hooks.c 171.5 KB
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/*
 *  NSA Security-Enhanced Linux (SELinux) security module
 *
 *  This file contains the SELinux hook function implementations.
 *
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 *  Authors:  Stephen Smalley, <sds@tycho.nsa.gov>
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 *	      Chris Vance, <cvance@nai.com>
 *	      Wayne Salamon, <wsalamon@nai.com>
 *	      James Morris <jmorris@redhat.com>
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 *
 *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
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 *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
 *					   Eric Paris <eparis@redhat.com>
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 *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
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 *			    <dgoeddel@trustedcs.com>
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 *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
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 *	Paul Moore <paul@paul-moore.com>
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 *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
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 *		       Yuichi Nakamura <ynakam@hitachisoft.jp>
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 *  Copyright (C) 2016 Mellanox Technologies
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 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License version 2,
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 *	as published by the Free Software Foundation.
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 */

#include <linux/init.h>
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#include <linux/kd.h>
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#include <linux/kernel.h>
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#include <linux/tracehook.h>
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#include <linux/errno.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/task.h>
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#include <linux/lsm_hooks.h>
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#include <linux/xattr.h>
#include <linux/capability.h>
#include <linux/unistd.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
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#include <linux/proc_fs.h>
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#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
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#include <linux/dcache.h>
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#include <linux/file.h>
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#include <linux/fdtable.h>
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#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/tty.h>
#include <net/icmp.h>
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#include <net/ip.h>		/* for local_port_range[] */
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#include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
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#include <net/inet_connection_sock.h>
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#include <net/net_namespace.h>
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#include <net/netlabel.h>
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#include <linux/uaccess.h>
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#include <asm/ioctls.h>
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#include <linux/atomic.h>
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#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>	/* for network interface checks */
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#include <net/netlink.h>
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#include <linux/tcp.h>
#include <linux/udp.h>
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#include <linux/dccp.h>
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#include <linux/quota.h>
#include <linux/un.h>		/* for Unix socket types */
#include <net/af_unix.h>	/* for Unix socket types */
#include <linux/parser.h>
#include <linux/nfs_mount.h>
#include <net/ipv6.h>
#include <linux/hugetlb.h>
#include <linux/personality.h>
#include <linux/audit.h>
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#include <linux/string.h>
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#include <linux/selinux.h>
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#include <linux/mutex.h>
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#include <linux/posix-timers.h>
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#include <linux/syslog.h>
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#include <linux/user_namespace.h>
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#include <linux/export.h>
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#include <linux/msg.h>
#include <linux/shm.h>
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#include <linux/bpf.h>
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#include "avc.h"
#include "objsec.h"
#include "netif.h"
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#include "netnode.h"
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#include "netport.h"
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#include "ibpkey.h"
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#include "xfrm.h"
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#include "netlabel.h"
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#include "audit.h"
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#include "avc_ss.h"
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/* SECMARK reference count */
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static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
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#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
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int selinux_enforcing;
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static int __init enforcing_setup(char *str)
{
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	unsigned long enforcing;
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	if (!kstrtoul(str, 0, &enforcing))
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		selinux_enforcing = enforcing ? 1 : 0;
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	return 1;
}
__setup("enforcing=", enforcing_setup);
#endif

#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;

static int __init selinux_enabled_setup(char *str)
{
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	unsigned long enabled;
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	if (!kstrtoul(str, 0, &enabled))
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		selinux_enabled = enabled ? 1 : 0;
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	return 1;
}
__setup("selinux=", selinux_enabled_setup);
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#else
int selinux_enabled = 1;
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#endif

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static struct kmem_cache *sel_inode_cache;
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static struct kmem_cache *file_security_cache;
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/**
 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
 *
 * Description:
 * This function checks the SECMARK reference counter to see if any SECMARK
 * targets are currently configured, if the reference counter is greater than
 * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
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 * enabled, false (0) if SECMARK is disabled.  If the always_check_network
 * policy capability is enabled, SECMARK is always considered enabled.
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 *
 */
static int selinux_secmark_enabled(void)
{
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	return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount));
}

/**
 * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
 *
 * Description:
 * This function checks if NetLabel or labeled IPSEC is enabled.  Returns true
 * (1) if any are enabled or false (0) if neither are enabled.  If the
 * always_check_network policy capability is enabled, peer labeling
 * is always considered enabled.
 *
 */
static int selinux_peerlbl_enabled(void)
{
	return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled());
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}

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static int selinux_netcache_avc_callback(u32 event)
{
	if (event == AVC_CALLBACK_RESET) {
		sel_netif_flush();
		sel_netnode_flush();
		sel_netport_flush();
		synchronize_net();
	}
	return 0;
}

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static int selinux_lsm_notifier_avc_callback(u32 event)
{
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	if (event == AVC_CALLBACK_RESET) {
		sel_ib_pkey_flush();
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		call_lsm_notifier(LSM_POLICY_CHANGE, NULL);
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	}
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	return 0;
}

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/*
 * initialise the security for the init task
 */
static void cred_init_security(void)
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{
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	struct cred *cred = (struct cred *) current->real_cred;
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	struct task_security_struct *tsec;

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	tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
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	if (!tsec)
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		panic("SELinux:  Failed to initialize initial task.\n");
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	tsec->osid = tsec->sid = SECINITSID_KERNEL;
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	cred->security = tsec;
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}

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/*
 * get the security ID of a set of credentials
 */
static inline u32 cred_sid(const struct cred *cred)
{
	const struct task_security_struct *tsec;

	tsec = cred->security;
	return tsec->sid;
}

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/*
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 * get the objective security ID of a task
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 */
static inline u32 task_sid(const struct task_struct *task)
{
	u32 sid;

	rcu_read_lock();
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	sid = cred_sid(__task_cred(task));
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	rcu_read_unlock();
	return sid;
}

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/* Allocate and free functions for each kind of security blob. */

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static int inode_alloc_security(struct inode *inode)
{
	struct inode_security_struct *isec;
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	u32 sid = current_sid();
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	isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
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	if (!isec)
		return -ENOMEM;

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	spin_lock_init(&isec->lock);
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	INIT_LIST_HEAD(&isec->list);
	isec->inode = inode;
	isec->sid = SECINITSID_UNLABELED;
	isec->sclass = SECCLASS_FILE;
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	isec->task_sid = sid;
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	isec->initialized = LABEL_INVALID;
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	inode->i_security = isec;

	return 0;
}

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static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);

/*
 * Try reloading inode security labels that have been marked as invalid.  The
 * @may_sleep parameter indicates when sleeping and thus reloading labels is
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 * allowed; when set to false, returns -ECHILD when the label is
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 * invalid.  The @opt_dentry parameter should be set to a dentry of the inode;
 * when no dentry is available, set it to NULL instead.
 */
static int __inode_security_revalidate(struct inode *inode,
				       struct dentry *opt_dentry,
				       bool may_sleep)
{
	struct inode_security_struct *isec = inode->i_security;

	might_sleep_if(may_sleep);

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	if (ss_initialized && isec->initialized != LABEL_INITIALIZED) {
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		if (!may_sleep)
			return -ECHILD;

		/*
		 * Try reloading the inode security label.  This will fail if
		 * @opt_dentry is NULL and no dentry for this inode can be
		 * found; in that case, continue using the old label.
		 */
		inode_doinit_with_dentry(inode, opt_dentry);
	}
	return 0;
}

static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
{
	return inode->i_security;
}

static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
{
	int error;

	error = __inode_security_revalidate(inode, NULL, !rcu);
	if (error)
		return ERR_PTR(error);
	return inode->i_security;
}

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/*
 * Get the security label of an inode.
 */
static struct inode_security_struct *inode_security(struct inode *inode)
{
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	__inode_security_revalidate(inode, NULL, true);
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	return inode->i_security;
}

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static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
{
	struct inode *inode = d_backing_inode(dentry);

	return inode->i_security;
}

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/*
 * Get the security label of a dentry's backing inode.
 */
static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
{
	struct inode *inode = d_backing_inode(dentry);

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	__inode_security_revalidate(inode, dentry, true);
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	return inode->i_security;
}

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static void inode_free_rcu(struct rcu_head *head)
{
	struct inode_security_struct *isec;

	isec = container_of(head, struct inode_security_struct, rcu);
	kmem_cache_free(sel_inode_cache, isec);
}

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static void inode_free_security(struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec = inode->i_sb->s_security;

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	/*
	 * As not all inode security structures are in a list, we check for
	 * empty list outside of the lock to make sure that we won't waste
	 * time taking a lock doing nothing.
	 *
	 * The list_del_init() function can be safely called more than once.
	 * It should not be possible for this function to be called with
	 * concurrent list_add(), but for better safety against future changes
	 * in the code, we use list_empty_careful() here.
	 */
	if (!list_empty_careful(&isec->list)) {
		spin_lock(&sbsec->isec_lock);
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		list_del_init(&isec->list);
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		spin_unlock(&sbsec->isec_lock);
	}
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	/*
	 * The inode may still be referenced in a path walk and
	 * a call to selinux_inode_permission() can be made
	 * after inode_free_security() is called. Ideally, the VFS
	 * wouldn't do this, but fixing that is a much harder
	 * job. For now, simply free the i_security via RCU, and
	 * leave the current inode->i_security pointer intact.
	 * The inode will be freed after the RCU grace period too.
	 */
	call_rcu(&isec->rcu, inode_free_rcu);
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}

static int file_alloc_security(struct file *file)
{
	struct file_security_struct *fsec;
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	u32 sid = current_sid();
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	fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL);
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	if (!fsec)
		return -ENOMEM;

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	fsec->sid = sid;
	fsec->fown_sid = sid;
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	file->f_security = fsec;

	return 0;
}

static void file_free_security(struct file *file)
{
	struct file_security_struct *fsec = file->f_security;
	file->f_security = NULL;
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	kmem_cache_free(file_security_cache, fsec);
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}

static int superblock_alloc_security(struct super_block *sb)
{
	struct superblock_security_struct *sbsec;

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	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
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	if (!sbsec)
		return -ENOMEM;

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	mutex_init(&sbsec->lock);
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	INIT_LIST_HEAD(&sbsec->isec_head);
	spin_lock_init(&sbsec->isec_lock);
	sbsec->sb = sb;
	sbsec->sid = SECINITSID_UNLABELED;
	sbsec->def_sid = SECINITSID_FILE;
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	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
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	sb->s_security = sbsec;

	return 0;
}

static void superblock_free_security(struct super_block *sb)
{
	struct superblock_security_struct *sbsec = sb->s_security;
	sb->s_security = NULL;
	kfree(sbsec);
}

static inline int inode_doinit(struct inode *inode)
{
	return inode_doinit_with_dentry(inode, NULL);
}

enum {
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	Opt_error = -1,
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	Opt_context = 1,
	Opt_fscontext = 2,
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	Opt_defcontext = 3,
	Opt_rootcontext = 4,
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	Opt_labelsupport = 5,
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	Opt_nextmntopt = 6,
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};

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#define NUM_SEL_MNT_OPTS	(Opt_nextmntopt - 1)

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static const match_table_t tokens = {
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	{Opt_context, CONTEXT_STR "%s"},
	{Opt_fscontext, FSCONTEXT_STR "%s"},
	{Opt_defcontext, DEFCONTEXT_STR "%s"},
	{Opt_rootcontext, ROOTCONTEXT_STR "%s"},
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	{Opt_labelsupport, LABELSUPP_STR},
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	{Opt_error, NULL},
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};

#define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"

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static int may_context_mount_sb_relabel(u32 sid,
			struct superblock_security_struct *sbsec,
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			const struct cred *cred)
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{
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	const struct task_security_struct *tsec = cred->security;
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	int rc;

	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
			  FILESYSTEM__RELABELFROM, NULL);
	if (rc)
		return rc;

	rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
			  FILESYSTEM__RELABELTO, NULL);
	return rc;
}

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static int may_context_mount_inode_relabel(u32 sid,
			struct superblock_security_struct *sbsec,
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			const struct cred *cred)
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{
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	const struct task_security_struct *tsec = cred->security;
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	int rc;
	rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
			  FILESYSTEM__RELABELFROM, NULL);
	if (rc)
		return rc;

	rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
			  FILESYSTEM__ASSOCIATE, NULL);
	return rc;
}

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static int selinux_is_sblabel_mnt(struct super_block *sb)
{
	struct superblock_security_struct *sbsec = sb->s_security;

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	return sbsec->behavior == SECURITY_FS_USE_XATTR ||
		sbsec->behavior == SECURITY_FS_USE_TRANS ||
		sbsec->behavior == SECURITY_FS_USE_TASK ||
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		sbsec->behavior == SECURITY_FS_USE_NATIVE ||
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		/* Special handling. Genfs but also in-core setxattr handler */
		!strcmp(sb->s_type->name, "sysfs") ||
		!strcmp(sb->s_type->name, "pstore") ||
		!strcmp(sb->s_type->name, "debugfs") ||
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		!strcmp(sb->s_type->name, "tracefs") ||
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		!strcmp(sb->s_type->name, "rootfs") ||
		(selinux_policycap_cgroupseclabel &&
		 (!strcmp(sb->s_type->name, "cgroup") ||
		  !strcmp(sb->s_type->name, "cgroup2")));
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}

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static int sb_finish_set_opts(struct super_block *sb)
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{
	struct superblock_security_struct *sbsec = sb->s_security;
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	struct dentry *root = sb->s_root;
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	struct inode *root_inode = d_backing_inode(root);
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	int rc = 0;
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	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
		/* Make sure that the xattr handler exists and that no
		   error other than -ENODATA is returned by getxattr on
		   the root directory.  -ENODATA is ok, as this may be
		   the first boot of the SELinux kernel before we have
		   assigned xattr values to the filesystem. */
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		if (!(root_inode->i_opflags & IOP_XATTR)) {
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			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
			       "xattr support\n", sb->s_id, sb->s_type->name);
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			rc = -EOPNOTSUPP;
			goto out;
		}
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		rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
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		if (rc < 0 && rc != -ENODATA) {
			if (rc == -EOPNOTSUPP)
				printk(KERN_WARNING "SELinux: (dev %s, type "
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				       "%s) has no security xattr handler\n",
				       sb->s_id, sb->s_type->name);
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			else
				printk(KERN_WARNING "SELinux: (dev %s, type "
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				       "%s) getxattr errno %d\n", sb->s_id,
				       sb->s_type->name, -rc);
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			goto out;
		}
	}
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	sbsec->flags |= SE_SBINITIALIZED;
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	/*
	 * Explicitly set or clear SBLABEL_MNT.  It's not sufficient to simply
	 * leave the flag untouched because sb_clone_mnt_opts might be handing
	 * us a superblock that needs the flag to be cleared.
	 */
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	if (selinux_is_sblabel_mnt(sb))
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		sbsec->flags |= SBLABEL_MNT;
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	else
		sbsec->flags &= ~SBLABEL_MNT;
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	/* Initialize the root inode. */
	rc = inode_doinit_with_dentry(root_inode, root);
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	/* Initialize any other inodes associated with the superblock, e.g.
	   inodes created prior to initial policy load or inodes created
	   during get_sb by a pseudo filesystem that directly
	   populates itself. */
	spin_lock(&sbsec->isec_lock);
next_inode:
	if (!list_empty(&sbsec->isec_head)) {
		struct inode_security_struct *isec =
				list_entry(sbsec->isec_head.next,
					   struct inode_security_struct, list);
		struct inode *inode = isec->inode;
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		list_del_init(&isec->list);
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		spin_unlock(&sbsec->isec_lock);
		inode = igrab(inode);
		if (inode) {
			if (!IS_PRIVATE(inode))
				inode_doinit(inode);
			iput(inode);
		}
		spin_lock(&sbsec->isec_lock);
		goto next_inode;
	}
	spin_unlock(&sbsec->isec_lock);
out:
	return rc;
}
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/*
 * This function should allow an FS to ask what it's mount security
 * options were so it can use those later for submounts, displaying
 * mount options, or whatever.
 */
static int selinux_get_mnt_opts(const struct super_block *sb,
576
				struct security_mnt_opts *opts)
577 578 579 580 581 582
{
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	char *context = NULL;
	u32 len;
	char tmp;
L
Linus Torvalds 已提交
583

584
	security_init_mnt_opts(opts);
L
Linus Torvalds 已提交
585

586
	if (!(sbsec->flags & SE_SBINITIALIZED))
587
		return -EINVAL;
L
Linus Torvalds 已提交
588

589 590
	if (!ss_initialized)
		return -EINVAL;
L
Linus Torvalds 已提交
591

592 593 594
	/* make sure we always check enough bits to cover the mask */
	BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));

595
	tmp = sbsec->flags & SE_MNTMASK;
596
	/* count the number of mount options for this sb */
597
	for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
598
		if (tmp & 0x01)
599
			opts->num_mnt_opts++;
600 601
		tmp >>= 1;
	}
602
	/* Check if the Label support flag is set */
603
	if (sbsec->flags & SBLABEL_MNT)
604
		opts->num_mnt_opts++;
L
Linus Torvalds 已提交
605

606 607
	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts) {
608 609 610
		rc = -ENOMEM;
		goto out_free;
	}
L
Linus Torvalds 已提交
611

612 613
	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
614 615 616
		rc = -ENOMEM;
		goto out_free;
	}
L
Linus Torvalds 已提交
617

618 619 620 621 622
	i = 0;
	if (sbsec->flags & FSCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->sid, &context, &len);
		if (rc)
			goto out_free;
623 624
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
625 626 627 628 629
	}
	if (sbsec->flags & CONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
		if (rc)
			goto out_free;
630 631
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
632 633 634 635 636
	}
	if (sbsec->flags & DEFCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
		if (rc)
			goto out_free;
637 638
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
639 640
	}
	if (sbsec->flags & ROOTCONTEXT_MNT) {
641 642
		struct dentry *root = sbsec->sb->s_root;
		struct inode_security_struct *isec = backing_inode_security(root);
643

644 645 646
		rc = security_sid_to_context(isec->sid, &context, &len);
		if (rc)
			goto out_free;
647 648
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
649
	}
650
	if (sbsec->flags & SBLABEL_MNT) {
651
		opts->mnt_opts[i] = NULL;
652
		opts->mnt_opts_flags[i++] = SBLABEL_MNT;
653
	}
L
Linus Torvalds 已提交
654

655
	BUG_ON(i != opts->num_mnt_opts);
L
Linus Torvalds 已提交
656

657 658 659
	return 0;

out_free:
660
	security_free_mnt_opts(opts);
661 662
	return rc;
}
L
Linus Torvalds 已提交
663

664 665 666
static int bad_option(struct superblock_security_struct *sbsec, char flag,
		      u32 old_sid, u32 new_sid)
{
667 668
	char mnt_flags = sbsec->flags & SE_MNTMASK;

669
	/* check if the old mount command had the same options */
670
	if (sbsec->flags & SE_SBINITIALIZED)
671 672 673 674 675 676 677
		if (!(sbsec->flags & flag) ||
		    (old_sid != new_sid))
			return 1;

	/* check if we were passed the same options twice,
	 * aka someone passed context=a,context=b
	 */
678 679
	if (!(sbsec->flags & SE_SBINITIALIZED))
		if (mnt_flags & flag)
680 681 682
			return 1;
	return 0;
}
683

684 685 686 687
/*
 * Allow filesystems with binary mount data to explicitly set mount point
 * labeling information.
 */
688
static int selinux_set_mnt_opts(struct super_block *sb,
689 690 691
				struct security_mnt_opts *opts,
				unsigned long kern_flags,
				unsigned long *set_kern_flags)
692
{
693
	const struct cred *cred = current_cred();
694 695
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
696
	const char *name = sb->s_type->name;
697
	struct dentry *root = sbsec->sb->s_root;
698
	struct inode_security_struct *root_isec;
699 700
	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
	u32 defcontext_sid = 0;
701 702 703
	char **mount_options = opts->mnt_opts;
	int *flags = opts->mnt_opts_flags;
	int num_opts = opts->num_mnt_opts;
704 705 706 707 708 709 710 711 712 713 714

	mutex_lock(&sbsec->lock);

	if (!ss_initialized) {
		if (!num_opts) {
			/* Defer initialization until selinux_complete_init,
			   after the initial policy is loaded and the security
			   server is ready to handle calls. */
			goto out;
		}
		rc = -EINVAL;
E
Eric Paris 已提交
715 716
		printk(KERN_WARNING "SELinux: Unable to set superblock options "
			"before the security server is initialized\n");
L
Linus Torvalds 已提交
717
		goto out;
718
	}
719 720 721 722 723 724
	if (kern_flags && !set_kern_flags) {
		/* Specifying internal flags without providing a place to
		 * place the results is not allowed */
		rc = -EINVAL;
		goto out;
	}
L
Linus Torvalds 已提交
725

726 727 728 729 730 731 732 733 734 735 736
	/*
	 * Binary mount data FS will come through this function twice.  Once
	 * from an explicit call and once from the generic calls from the vfs.
	 * Since the generic VFS calls will not contain any security mount data
	 * we need to skip the double mount verification.
	 *
	 * This does open a hole in which we will not notice if the first
	 * mount using this sb set explict options and a second mount using
	 * this sb does not set any security options.  (The first options
	 * will be used for both mounts)
	 */
737
	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
738
	    && (num_opts == 0))
739
		goto out;
740

741 742
	root_isec = backing_inode_security_novalidate(root);

743 744 745 746 747 748 749
	/*
	 * parse the mount options, check if they are valid sids.
	 * also check if someone is trying to mount the same sb more
	 * than once with different security options.
	 */
	for (i = 0; i < num_opts; i++) {
		u32 sid;
750

751
		if (flags[i] == SBLABEL_MNT)
752
			continue;
753
		rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL);
L
Linus Torvalds 已提交
754
		if (rc) {
755
			printk(KERN_WARNING "SELinux: security_context_str_to_sid"
756 757
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, name, rc);
758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801
			goto out;
		}
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			fscontext_sid = sid;

			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
					fscontext_sid))
				goto out_double_mount;

			sbsec->flags |= FSCONTEXT_MNT;
			break;
		case CONTEXT_MNT:
			context_sid = sid;

			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
					context_sid))
				goto out_double_mount;

			sbsec->flags |= CONTEXT_MNT;
			break;
		case ROOTCONTEXT_MNT:
			rootcontext_sid = sid;

			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
					rootcontext_sid))
				goto out_double_mount;

			sbsec->flags |= ROOTCONTEXT_MNT;

			break;
		case DEFCONTEXT_MNT:
			defcontext_sid = sid;

			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
					defcontext_sid))
				goto out_double_mount;

			sbsec->flags |= DEFCONTEXT_MNT;

			break;
		default:
			rc = -EINVAL;
			goto out;
L
Linus Torvalds 已提交
802
		}
803 804
	}

805
	if (sbsec->flags & SE_SBINITIALIZED) {
806
		/* previously mounted with options, but not on this attempt? */
807
		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
808 809 810 811 812
			goto out_double_mount;
		rc = 0;
		goto out;
	}

813
	if (strcmp(sb->s_type->name, "proc") == 0)
814 815
		sbsec->flags |= SE_SBPROC | SE_SBGENFS;

816
	if (!strcmp(sb->s_type->name, "debugfs") ||
817
	    !strcmp(sb->s_type->name, "tracefs") ||
818
	    !strcmp(sb->s_type->name, "sysfs") ||
819 820 821
	    !strcmp(sb->s_type->name, "pstore") ||
	    !strcmp(sb->s_type->name, "cgroup") ||
	    !strcmp(sb->s_type->name, "cgroup2"))
822
		sbsec->flags |= SE_SBGENFS;
823

824 825 826 827 828
	if (!sbsec->behavior) {
		/*
		 * Determine the labeling behavior to use for this
		 * filesystem type.
		 */
829
		rc = security_fs_use(sb);
830 831 832 833 834 835
		if (rc) {
			printk(KERN_WARNING
				"%s: security_fs_use(%s) returned %d\n",
					__func__, sb->s_type->name, rc);
			goto out;
		}
836
	}
837 838

	/*
839 840 841
	 * If this is a user namespace mount and the filesystem type is not
	 * explicitly whitelisted, then no contexts are allowed on the command
	 * line and security labels must be ignored.
842
	 */
843 844 845 846
	if (sb->s_user_ns != &init_user_ns &&
	    strcmp(sb->s_type->name, "tmpfs") &&
	    strcmp(sb->s_type->name, "ramfs") &&
	    strcmp(sb->s_type->name, "devpts")) {
847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862
		if (context_sid || fscontext_sid || rootcontext_sid ||
		    defcontext_sid) {
			rc = -EACCES;
			goto out;
		}
		if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
			sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
			rc = security_transition_sid(current_sid(), current_sid(),
						     SECCLASS_FILE, NULL,
						     &sbsec->mntpoint_sid);
			if (rc)
				goto out;
		}
		goto out_set_opts;
	}

863 864
	/* sets the context of the superblock for the fs being mounted. */
	if (fscontext_sid) {
865
		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
L
Linus Torvalds 已提交
866
		if (rc)
867
			goto out;
L
Linus Torvalds 已提交
868

869
		sbsec->sid = fscontext_sid;
870 871 872 873 874 875 876
	}

	/*
	 * Switch to using mount point labeling behavior.
	 * sets the label used on all file below the mountpoint, and will set
	 * the superblock context if not already set.
	 */
877 878 879 880 881
	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
		sbsec->behavior = SECURITY_FS_USE_NATIVE;
		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
	}

882 883
	if (context_sid) {
		if (!fscontext_sid) {
884 885
			rc = may_context_mount_sb_relabel(context_sid, sbsec,
							  cred);
886
			if (rc)
887 888
				goto out;
			sbsec->sid = context_sid;
889
		} else {
890 891
			rc = may_context_mount_inode_relabel(context_sid, sbsec,
							     cred);
892
			if (rc)
893
				goto out;
894
		}
895 896
		if (!rootcontext_sid)
			rootcontext_sid = context_sid;
L
Linus Torvalds 已提交
897

898
		sbsec->mntpoint_sid = context_sid;
899
		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
L
Linus Torvalds 已提交
900 901
	}

902
	if (rootcontext_sid) {
903 904
		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
						     cred);
905
		if (rc)
906
			goto out;
907

908
		root_isec->sid = rootcontext_sid;
909
		root_isec->initialized = LABEL_INITIALIZED;
910 911
	}

912
	if (defcontext_sid) {
913 914
		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
915 916 917 918
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux: defcontext option is "
			       "invalid for this filesystem type\n");
			goto out;
L
Linus Torvalds 已提交
919 920
		}

921 922
		if (defcontext_sid != sbsec->def_sid) {
			rc = may_context_mount_inode_relabel(defcontext_sid,
923
							     sbsec, cred);
924 925 926
			if (rc)
				goto out;
		}
L
Linus Torvalds 已提交
927

928
		sbsec->def_sid = defcontext_sid;
L
Linus Torvalds 已提交
929 930
	}

931
out_set_opts:
932
	rc = sb_finish_set_opts(sb);
L
Linus Torvalds 已提交
933
out:
934
	mutex_unlock(&sbsec->lock);
L
Linus Torvalds 已提交
935
	return rc;
936 937 938
out_double_mount:
	rc = -EINVAL;
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
939
	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
940
	goto out;
L
Linus Torvalds 已提交
941 942
}

943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959
static int selinux_cmp_sb_context(const struct super_block *oldsb,
				    const struct super_block *newsb)
{
	struct superblock_security_struct *old = oldsb->s_security;
	struct superblock_security_struct *new = newsb->s_security;
	char oldflags = old->flags & SE_MNTMASK;
	char newflags = new->flags & SE_MNTMASK;

	if (oldflags != newflags)
		goto mismatch;
	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
		goto mismatch;
	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
		goto mismatch;
	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
		goto mismatch;
	if (oldflags & ROOTCONTEXT_MNT) {
960 961
		struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
		struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
962 963 964 965 966 967 968 969 970 971 972 973
		if (oldroot->sid != newroot->sid)
			goto mismatch;
	}
	return 0;
mismatch:
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, "
			    "different security settings for (dev %s, "
			    "type %s)\n", newsb->s_id, newsb->s_type->name);
	return -EBUSY;
}

static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
974 975 976
					struct super_block *newsb,
					unsigned long kern_flags,
					unsigned long *set_kern_flags)
L
Linus Torvalds 已提交
977
{
978
	int rc = 0;
979 980
	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
	struct superblock_security_struct *newsbsec = newsb->s_security;
L
Linus Torvalds 已提交
981

982 983 984
	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);
L
Linus Torvalds 已提交
985

986 987
	/*
	 * if the parent was able to be mounted it clearly had no special lsm
988
	 * mount options.  thus we can safely deal with this superblock later
989
	 */
990
	if (!ss_initialized)
991
		return 0;
992

993 994 995 996 997 998 999
	/*
	 * Specifying internal flags without providing a place to
	 * place the results is not allowed.
	 */
	if (kern_flags && !set_kern_flags)
		return -EINVAL;

1000
	/* how can we clone if the old one wasn't set up?? */
1001
	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
1002

1003
	/* if fs is reusing a sb, make sure that the contexts match */
1004
	if (newsbsec->flags & SE_SBINITIALIZED)
1005
		return selinux_cmp_sb_context(oldsb, newsb);
1006

1007 1008 1009 1010 1011 1012 1013 1014
	mutex_lock(&newsbsec->lock);

	newsbsec->flags = oldsbsec->flags;

	newsbsec->sid = oldsbsec->sid;
	newsbsec->def_sid = oldsbsec->def_sid;
	newsbsec->behavior = oldsbsec->behavior;

1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026
	if (newsbsec->behavior == SECURITY_FS_USE_NATIVE &&
		!(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) {
		rc = security_fs_use(newsb);
		if (rc)
			goto out;
	}

	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) {
		newsbsec->behavior = SECURITY_FS_USE_NATIVE;
		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
	}

1027 1028 1029 1030 1031 1032
	if (set_context) {
		u32 sid = oldsbsec->mntpoint_sid;

		if (!set_fscontext)
			newsbsec->sid = sid;
		if (!set_rootcontext) {
1033
			struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
1034 1035 1036
			newisec->sid = sid;
		}
		newsbsec->mntpoint_sid = sid;
L
Linus Torvalds 已提交
1037
	}
1038
	if (set_rootcontext) {
1039 1040
		const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
		struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
L
Linus Torvalds 已提交
1041

1042
		newisec->sid = oldisec->sid;
L
Linus Torvalds 已提交
1043 1044
	}

1045
	sb_finish_set_opts(newsb);
1046
out:
1047
	mutex_unlock(&newsbsec->lock);
1048
	return rc;
1049 1050
}

1051 1052
static int selinux_parse_opts_str(char *options,
				  struct security_mnt_opts *opts)
1053
{
1054
	char *p;
1055 1056
	char *context = NULL, *defcontext = NULL;
	char *fscontext = NULL, *rootcontext = NULL;
1057
	int rc, num_mnt_opts = 0;
L
Linus Torvalds 已提交
1058

1059
	opts->num_mnt_opts = 0;
L
Linus Torvalds 已提交
1060

1061 1062 1063 1064
	/* Standard string-based options. */
	while ((p = strsep(&options, "|")) != NULL) {
		int token;
		substring_t args[MAX_OPT_ARGS];
L
Linus Torvalds 已提交
1065

1066 1067
		if (!*p)
			continue;
L
Linus Torvalds 已提交
1068

1069
		token = match_token(p, tokens, args);
L
Linus Torvalds 已提交
1070

1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122
		switch (token) {
		case Opt_context:
			if (context || defcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			context = match_strdup(&args[0]);
			if (!context) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_fscontext:
			if (fscontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			fscontext = match_strdup(&args[0]);
			if (!fscontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_rootcontext:
			if (rootcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			rootcontext = match_strdup(&args[0]);
			if (!rootcontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

		case Opt_defcontext:
			if (context || defcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			defcontext = match_strdup(&args[0]);
			if (!defcontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;
1123 1124
		case Opt_labelsupport:
			break;
1125 1126 1127 1128
		default:
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux:  unknown mount option\n");
			goto out_err;
L
Linus Torvalds 已提交
1129 1130 1131

		}
	}
1132

1133
	rc = -ENOMEM;
1134
	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_KERNEL);
1135 1136 1137
	if (!opts->mnt_opts)
		goto out_err;

1138 1139
	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int),
				       GFP_KERNEL);
1140
	if (!opts->mnt_opts_flags)
1141 1142
		goto out_err;

1143
	if (fscontext) {
1144 1145
		opts->mnt_opts[num_mnt_opts] = fscontext;
		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
1146 1147
	}
	if (context) {
1148 1149
		opts->mnt_opts[num_mnt_opts] = context;
		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
1150 1151
	}
	if (rootcontext) {
1152 1153
		opts->mnt_opts[num_mnt_opts] = rootcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
1154 1155
	}
	if (defcontext) {
1156 1157
		opts->mnt_opts[num_mnt_opts] = defcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
1158 1159
	}

1160 1161 1162
	opts->num_mnt_opts = num_mnt_opts;
	return 0;

1163
out_err:
1164
	security_free_mnt_opts(opts);
1165 1166 1167 1168
	kfree(context);
	kfree(defcontext);
	kfree(fscontext);
	kfree(rootcontext);
L
Linus Torvalds 已提交
1169 1170
	return rc;
}
1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191
/*
 * string mount options parsing and call set the sbsec
 */
static int superblock_doinit(struct super_block *sb, void *data)
{
	int rc = 0;
	char *options = data;
	struct security_mnt_opts opts;

	security_init_mnt_opts(&opts);

	if (!data)
		goto out;

	BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);

	rc = selinux_parse_opts_str(options, &opts);
	if (rc)
		goto out_err;

out:
1192
	rc = selinux_set_mnt_opts(sb, &opts, 0, NULL);
1193 1194 1195 1196 1197

out_err:
	security_free_mnt_opts(&opts);
	return rc;
}
L
Linus Torvalds 已提交
1198

A
Adrian Bunk 已提交
1199 1200
static void selinux_write_opts(struct seq_file *m,
			       struct security_mnt_opts *opts)
1201 1202 1203 1204 1205
{
	int i;
	char *prefix;

	for (i = 0; i < opts->num_mnt_opts; i++) {
1206 1207 1208 1209 1210 1211
		char *has_comma;

		if (opts->mnt_opts[i])
			has_comma = strchr(opts->mnt_opts[i], ',');
		else
			has_comma = NULL;
1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225

		switch (opts->mnt_opts_flags[i]) {
		case CONTEXT_MNT:
			prefix = CONTEXT_STR;
			break;
		case FSCONTEXT_MNT:
			prefix = FSCONTEXT_STR;
			break;
		case ROOTCONTEXT_MNT:
			prefix = ROOTCONTEXT_STR;
			break;
		case DEFCONTEXT_MNT:
			prefix = DEFCONTEXT_STR;
			break;
1226
		case SBLABEL_MNT:
1227 1228 1229
			seq_putc(m, ',');
			seq_puts(m, LABELSUPP_STR);
			continue;
1230 1231
		default:
			BUG();
1232
			return;
1233 1234 1235 1236 1237 1238
		};
		/* we need a comma before each option */
		seq_putc(m, ',');
		seq_puts(m, prefix);
		if (has_comma)
			seq_putc(m, '\"');
1239
		seq_escape(m, opts->mnt_opts[i], "\"\n\\");
1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250
		if (has_comma)
			seq_putc(m, '\"');
	}
}

static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
{
	struct security_mnt_opts opts;
	int rc;

	rc = selinux_get_mnt_opts(sb, &opts);
1251 1252 1253 1254
	if (rc) {
		/* before policy load we may get EINVAL, don't show anything */
		if (rc == -EINVAL)
			rc = 0;
1255
		return rc;
1256
	}
1257 1258 1259 1260 1261 1262 1263 1264

	selinux_write_opts(m, &opts);

	security_free_mnt_opts(&opts);

	return rc;
}

L
Linus Torvalds 已提交
1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287
static inline u16 inode_mode_to_security_class(umode_t mode)
{
	switch (mode & S_IFMT) {
	case S_IFSOCK:
		return SECCLASS_SOCK_FILE;
	case S_IFLNK:
		return SECCLASS_LNK_FILE;
	case S_IFREG:
		return SECCLASS_FILE;
	case S_IFBLK:
		return SECCLASS_BLK_FILE;
	case S_IFDIR:
		return SECCLASS_DIR;
	case S_IFCHR:
		return SECCLASS_CHR_FILE;
	case S_IFIFO:
		return SECCLASS_FIFO_FILE;

	}

	return SECCLASS_FILE;
}

1288 1289 1290 1291 1292 1293 1294 1295 1296 1297
static inline int default_protocol_stream(int protocol)
{
	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
}

static inline int default_protocol_dgram(int protocol)
{
	return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
}

L
Linus Torvalds 已提交
1298 1299
static inline u16 socket_type_to_security_class(int family, int type, int protocol)
{
1300 1301
	int extsockclass = selinux_policycap_extsockclass;

L
Linus Torvalds 已提交
1302 1303 1304 1305 1306 1307 1308
	switch (family) {
	case PF_UNIX:
		switch (type) {
		case SOCK_STREAM:
		case SOCK_SEQPACKET:
			return SECCLASS_UNIX_STREAM_SOCKET;
		case SOCK_DGRAM:
1309
		case SOCK_RAW:
L
Linus Torvalds 已提交
1310 1311 1312 1313 1314 1315 1316
			return SECCLASS_UNIX_DGRAM_SOCKET;
		}
		break;
	case PF_INET:
	case PF_INET6:
		switch (type) {
		case SOCK_STREAM:
1317
		case SOCK_SEQPACKET:
1318 1319
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
1320 1321
			else if (extsockclass && protocol == IPPROTO_SCTP)
				return SECCLASS_SCTP_SOCKET;
1322 1323
			else
				return SECCLASS_RAWIP_SOCKET;
L
Linus Torvalds 已提交
1324
		case SOCK_DGRAM:
1325 1326
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
1327 1328
			else if (extsockclass && (protocol == IPPROTO_ICMP ||
						  protocol == IPPROTO_ICMPV6))
1329
				return SECCLASS_ICMP_SOCKET;
1330 1331
			else
				return SECCLASS_RAWIP_SOCKET;
J
James Morris 已提交
1332 1333
		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
1334
		default:
L
Linus Torvalds 已提交
1335 1336 1337 1338 1339 1340 1341
			return SECCLASS_RAWIP_SOCKET;
		}
		break;
	case PF_NETLINK:
		switch (protocol) {
		case NETLINK_ROUTE:
			return SECCLASS_NETLINK_ROUTE_SOCKET;
1342
		case NETLINK_SOCK_DIAG:
L
Linus Torvalds 已提交
1343 1344 1345 1346 1347 1348 1349
			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
		case NETLINK_NFLOG:
			return SECCLASS_NETLINK_NFLOG_SOCKET;
		case NETLINK_XFRM:
			return SECCLASS_NETLINK_XFRM_SOCKET;
		case NETLINK_SELINUX:
			return SECCLASS_NETLINK_SELINUX_SOCKET;
1350 1351
		case NETLINK_ISCSI:
			return SECCLASS_NETLINK_ISCSI_SOCKET;
L
Linus Torvalds 已提交
1352 1353
		case NETLINK_AUDIT:
			return SECCLASS_NETLINK_AUDIT_SOCKET;
1354 1355 1356 1357 1358 1359
		case NETLINK_FIB_LOOKUP:
			return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
		case NETLINK_CONNECTOR:
			return SECCLASS_NETLINK_CONNECTOR_SOCKET;
		case NETLINK_NETFILTER:
			return SECCLASS_NETLINK_NETFILTER_SOCKET;
L
Linus Torvalds 已提交
1360 1361
		case NETLINK_DNRTMSG:
			return SECCLASS_NETLINK_DNRT_SOCKET;
1362 1363
		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1364 1365 1366 1367 1368 1369 1370 1371
		case NETLINK_GENERIC:
			return SECCLASS_NETLINK_GENERIC_SOCKET;
		case NETLINK_SCSITRANSPORT:
			return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
		case NETLINK_RDMA:
			return SECCLASS_NETLINK_RDMA_SOCKET;
		case NETLINK_CRYPTO:
			return SECCLASS_NETLINK_CRYPTO_SOCKET;
L
Linus Torvalds 已提交
1372 1373 1374 1375 1376 1377 1378
		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
1379 1380
	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
L
Linus Torvalds 已提交
1381 1382
	}

1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436
	if (extsockclass) {
		switch (family) {
		case PF_AX25:
			return SECCLASS_AX25_SOCKET;
		case PF_IPX:
			return SECCLASS_IPX_SOCKET;
		case PF_NETROM:
			return SECCLASS_NETROM_SOCKET;
		case PF_ATMPVC:
			return SECCLASS_ATMPVC_SOCKET;
		case PF_X25:
			return SECCLASS_X25_SOCKET;
		case PF_ROSE:
			return SECCLASS_ROSE_SOCKET;
		case PF_DECnet:
			return SECCLASS_DECNET_SOCKET;
		case PF_ATMSVC:
			return SECCLASS_ATMSVC_SOCKET;
		case PF_RDS:
			return SECCLASS_RDS_SOCKET;
		case PF_IRDA:
			return SECCLASS_IRDA_SOCKET;
		case PF_PPPOX:
			return SECCLASS_PPPOX_SOCKET;
		case PF_LLC:
			return SECCLASS_LLC_SOCKET;
		case PF_CAN:
			return SECCLASS_CAN_SOCKET;
		case PF_TIPC:
			return SECCLASS_TIPC_SOCKET;
		case PF_BLUETOOTH:
			return SECCLASS_BLUETOOTH_SOCKET;
		case PF_IUCV:
			return SECCLASS_IUCV_SOCKET;
		case PF_RXRPC:
			return SECCLASS_RXRPC_SOCKET;
		case PF_ISDN:
			return SECCLASS_ISDN_SOCKET;
		case PF_PHONET:
			return SECCLASS_PHONET_SOCKET;
		case PF_IEEE802154:
			return SECCLASS_IEEE802154_SOCKET;
		case PF_CAIF:
			return SECCLASS_CAIF_SOCKET;
		case PF_ALG:
			return SECCLASS_ALG_SOCKET;
		case PF_NFC:
			return SECCLASS_NFC_SOCKET;
		case PF_VSOCK:
			return SECCLASS_VSOCK_SOCKET;
		case PF_KCM:
			return SECCLASS_KCM_SOCKET;
		case PF_QIPCRTR:
			return SECCLASS_QIPCRTR_SOCKET;
1437 1438 1439
		case PF_SMC:
			return SECCLASS_SMC_SOCKET;
#if PF_MAX > 44
1440 1441 1442 1443 1444
#error New address family defined, please update this function.
#endif
		}
	}

L
Linus Torvalds 已提交
1445 1446 1447
	return SECCLASS_SOCKET;
}

1448 1449 1450 1451
static int selinux_genfs_get_sid(struct dentry *dentry,
				 u16 tclass,
				 u16 flags,
				 u32 *sid)
L
Linus Torvalds 已提交
1452
{
1453
	int rc;
1454
	struct super_block *sb = dentry->d_sb;
1455
	char *buffer, *path;
L
Linus Torvalds 已提交
1456

1457
	buffer = (char *)__get_free_page(GFP_KERNEL);
L
Linus Torvalds 已提交
1458 1459 1460
	if (!buffer)
		return -ENOMEM;

1461 1462 1463 1464
	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
	if (IS_ERR(path))
		rc = PTR_ERR(path);
	else {
1465 1466 1467 1468 1469 1470 1471 1472
		if (flags & SE_SBPROC) {
			/* each process gets a /proc/PID/ entry. Strip off the
			 * PID part to get a valid selinux labeling.
			 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
			while (path[1] >= '0' && path[1] <= '9') {
				path[1] = '/';
				path++;
			}
1473
		}
1474
		rc = security_genfs_sid(sb->s_type->name, path, tclass, sid);
L
Linus Torvalds 已提交
1475 1476 1477 1478 1479 1480 1481 1482 1483 1484
	}
	free_page((unsigned long)buffer);
	return rc;
}

/* The inode's security attributes must be initialized before first use. */
static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
{
	struct superblock_security_struct *sbsec = NULL;
	struct inode_security_struct *isec = inode->i_security;
1485 1486
	u32 task_sid, sid = 0;
	u16 sclass;
L
Linus Torvalds 已提交
1487 1488 1489 1490 1491 1492
	struct dentry *dentry;
#define INITCONTEXTLEN 255
	char *context = NULL;
	unsigned len = 0;
	int rc = 0;

1493
	if (isec->initialized == LABEL_INITIALIZED)
1494
		return 0;
L
Linus Torvalds 已提交
1495

1496
	spin_lock(&isec->lock);
1497
	if (isec->initialized == LABEL_INITIALIZED)
1498
		goto out_unlock;
L
Linus Torvalds 已提交
1499

1500 1501 1502
	if (isec->sclass == SECCLASS_FILE)
		isec->sclass = inode_mode_to_security_class(inode->i_mode);

L
Linus Torvalds 已提交
1503
	sbsec = inode->i_sb->s_security;
1504
	if (!(sbsec->flags & SE_SBINITIALIZED)) {
L
Linus Torvalds 已提交
1505 1506 1507 1508 1509 1510 1511
		/* Defer initialization until selinux_complete_init,
		   after the initial policy is loaded and the security
		   server is ready to handle calls. */
		spin_lock(&sbsec->isec_lock);
		if (list_empty(&isec->list))
			list_add(&isec->list, &sbsec->isec_head);
		spin_unlock(&sbsec->isec_lock);
1512
		goto out_unlock;
L
Linus Torvalds 已提交
1513 1514
	}

1515 1516 1517 1518 1519 1520
	sclass = isec->sclass;
	task_sid = isec->task_sid;
	sid = isec->sid;
	isec->initialized = LABEL_PENDING;
	spin_unlock(&isec->lock);

L
Linus Torvalds 已提交
1521
	switch (sbsec->behavior) {
1522 1523
	case SECURITY_FS_USE_NATIVE:
		break;
L
Linus Torvalds 已提交
1524
	case SECURITY_FS_USE_XATTR:
1525
		if (!(inode->i_opflags & IOP_XATTR)) {
1526
			sid = sbsec->def_sid;
L
Linus Torvalds 已提交
1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538
			break;
		}
		/* Need a dentry, since the xattr API requires one.
		   Life would be simpler if we could just pass the inode. */
		if (opt_dentry) {
			/* Called from d_instantiate or d_splice_alias. */
			dentry = dget(opt_dentry);
		} else {
			/* Called from selinux_complete_init, try to find a dentry. */
			dentry = d_find_alias(inode);
		}
		if (!dentry) {
1539 1540 1541 1542 1543 1544 1545 1546 1547
			/*
			 * this is can be hit on boot when a file is accessed
			 * before the policy is loaded.  When we load policy we
			 * may find inodes that have no dentry on the
			 * sbsec->isec_head list.  No reason to complain as these
			 * will get fixed up the next time we go through
			 * inode_doinit with a dentry, before these inodes could
			 * be used again by userspace.
			 */
1548
			goto out;
L
Linus Torvalds 已提交
1549 1550 1551
		}

		len = INITCONTEXTLEN;
1552
		context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1553 1554 1555
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
1556
			goto out;
L
Linus Torvalds 已提交
1557
		}
1558
		context[len] = '\0';
1559
		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
L
Linus Torvalds 已提交
1560
		if (rc == -ERANGE) {
1561 1562
			kfree(context);

L
Linus Torvalds 已提交
1563
			/* Need a larger buffer.  Query for the right size. */
1564
			rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
L
Linus Torvalds 已提交
1565 1566
			if (rc < 0) {
				dput(dentry);
1567
				goto out;
L
Linus Torvalds 已提交
1568 1569
			}
			len = rc;
1570
			context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1571 1572 1573
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
1574
				goto out;
L
Linus Torvalds 已提交
1575
			}
1576
			context[len] = '\0';
1577
			rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
L
Linus Torvalds 已提交
1578 1579 1580 1581
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
E
Eric Paris 已提交
1582
				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1583
				       "%d for dev=%s ino=%ld\n", __func__,
L
Linus Torvalds 已提交
1584 1585
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
1586
				goto out;
L
Linus Torvalds 已提交
1587 1588 1589 1590 1591
			}
			/* Map ENODATA to the default file SID */
			sid = sbsec->def_sid;
			rc = 0;
		} else {
1592
			rc = security_context_to_sid_default(context, rc, &sid,
1593 1594
							     sbsec->def_sid,
							     GFP_NOFS);
L
Linus Torvalds 已提交
1595
			if (rc) {
1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608
				char *dev = inode->i_sb->s_id;
				unsigned long ino = inode->i_ino;

				if (rc == -EINVAL) {
					if (printk_ratelimit())
						printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
							"context=%s.  This indicates you may need to relabel the inode or the "
							"filesystem in question.\n", ino, dev, context);
				} else {
					printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
					       "returned %d for dev=%s ino=%ld\n",
					       __func__, context, -rc, dev, ino);
				}
L
Linus Torvalds 已提交
1609 1610 1611 1612 1613 1614 1615 1616 1617
				kfree(context);
				/* Leave with the unlabeled SID */
				rc = 0;
				break;
			}
		}
		kfree(context);
		break;
	case SECURITY_FS_USE_TASK:
1618
		sid = task_sid;
L
Linus Torvalds 已提交
1619 1620 1621
		break;
	case SECURITY_FS_USE_TRANS:
		/* Default to the fs SID. */
1622
		sid = sbsec->sid;
L
Linus Torvalds 已提交
1623 1624

		/* Try to obtain a transition SID. */
1625
		rc = security_transition_sid(task_sid, sid, sclass, NULL, &sid);
L
Linus Torvalds 已提交
1626
		if (rc)
1627
			goto out;
L
Linus Torvalds 已提交
1628
		break;
1629
	case SECURITY_FS_USE_MNTPOINT:
1630
		sid = sbsec->mntpoint_sid;
1631
		break;
L
Linus Torvalds 已提交
1632
	default:
1633
		/* Default to the fs superblock SID. */
1634
		sid = sbsec->sid;
L
Linus Torvalds 已提交
1635

1636
		if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) {
1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656
			/* We must have a dentry to determine the label on
			 * procfs inodes */
			if (opt_dentry)
				/* Called from d_instantiate or
				 * d_splice_alias. */
				dentry = dget(opt_dentry);
			else
				/* Called from selinux_complete_init, try to
				 * find a dentry. */
				dentry = d_find_alias(inode);
			/*
			 * This can be hit on boot when a file is accessed
			 * before the policy is loaded.  When we load policy we
			 * may find inodes that have no dentry on the
			 * sbsec->isec_head list.  No reason to complain as
			 * these will get fixed up the next time we go through
			 * inode_doinit() with a dentry, before these inodes
			 * could be used again by userspace.
			 */
			if (!dentry)
1657 1658
				goto out;
			rc = selinux_genfs_get_sid(dentry, sclass,
1659
						   sbsec->flags, &sid);
1660 1661
			dput(dentry);
			if (rc)
1662
				goto out;
L
Linus Torvalds 已提交
1663 1664 1665 1666
		}
		break;
	}

1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677
out:
	spin_lock(&isec->lock);
	if (isec->initialized == LABEL_PENDING) {
		if (!sid || rc) {
			isec->initialized = LABEL_INVALID;
			goto out_unlock;
		}

		isec->initialized = LABEL_INITIALIZED;
		isec->sid = sid;
	}
L
Linus Torvalds 已提交
1678

1679
out_unlock:
1680
	spin_unlock(&isec->lock);
L
Linus Torvalds 已提交
1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710
	return rc;
}

/* Convert a Linux signal to an access vector. */
static inline u32 signal_to_av(int sig)
{
	u32 perm = 0;

	switch (sig) {
	case SIGCHLD:
		/* Commonly granted from child to parent. */
		perm = PROCESS__SIGCHLD;
		break;
	case SIGKILL:
		/* Cannot be caught or ignored */
		perm = PROCESS__SIGKILL;
		break;
	case SIGSTOP:
		/* Cannot be caught or ignored */
		perm = PROCESS__SIGSTOP;
		break;
	default:
		/* All other signals. */
		perm = PROCESS__SIGNAL;
		break;
	}

	return perm;
}

1711 1712 1713 1714
#if CAP_LAST_CAP > 63
#error Fix SELinux to handle capabilities > 63.
#endif

L
Linus Torvalds 已提交
1715
/* Check whether a task is allowed to use a capability. */
1716
static int cred_has_capability(const struct cred *cred,
1717
			       int cap, int audit, bool initns)
L
Linus Torvalds 已提交
1718
{
1719
	struct common_audit_data ad;
1720
	struct av_decision avd;
1721
	u16 sclass;
1722
	u32 sid = cred_sid(cred);
1723
	u32 av = CAP_TO_MASK(cap);
1724
	int rc;
L
Linus Torvalds 已提交
1725

1726
	ad.type = LSM_AUDIT_DATA_CAP;
L
Linus Torvalds 已提交
1727 1728
	ad.u.cap = cap;

1729 1730
	switch (CAP_TO_INDEX(cap)) {
	case 0:
1731
		sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1732 1733
		break;
	case 1:
1734
		sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1735 1736 1737 1738 1739
		break;
	default:
		printk(KERN_ERR
		       "SELinux:  out of range capability %d\n", cap);
		BUG();
1740
		return -EINVAL;
1741
	}
1742

1743
	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1744
	if (audit == SECURITY_CAP_AUDIT) {
1745
		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1746 1747 1748
		if (rc2)
			return rc2;
	}
1749
	return rc;
L
Linus Torvalds 已提交
1750 1751 1752 1753 1754
}

/* Check whether a task has a particular permission to an inode.
   The 'adp' parameter is optional and allows other audit
   data to be passed (e.g. the dentry). */
1755
static int inode_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1756 1757
			  struct inode *inode,
			  u32 perms,
1758
			  struct common_audit_data *adp)
L
Linus Torvalds 已提交
1759 1760
{
	struct inode_security_struct *isec;
1761
	u32 sid;
L
Linus Torvalds 已提交
1762

1763 1764
	validate_creds(cred);

1765
	if (unlikely(IS_PRIVATE(inode)))
1766 1767
		return 0;

1768
	sid = cred_sid(cred);
L
Linus Torvalds 已提交
1769 1770
	isec = inode->i_security;

1771
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
L
Linus Torvalds 已提交
1772 1773 1774 1775 1776
}

/* Same as inode_has_perm, but pass explicit audit data containing
   the dentry to help the auditing code to more easily generate the
   pathname if needed. */
1777
static inline int dentry_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1778 1779 1780
				  struct dentry *dentry,
				  u32 av)
{
1781
	struct inode *inode = d_backing_inode(dentry);
1782
	struct common_audit_data ad;
1783

1784
	ad.type = LSM_AUDIT_DATA_DENTRY;
E
Eric Paris 已提交
1785
	ad.u.dentry = dentry;
1786
	__inode_security_revalidate(inode, dentry, true);
1787
	return inode_has_perm(cred, inode, av, &ad);
E
Eric Paris 已提交
1788 1789 1790 1791 1792 1793
}

/* Same as inode_has_perm, but pass explicit audit data containing
   the path to help the auditing code to more easily generate the
   pathname if needed. */
static inline int path_has_perm(const struct cred *cred,
1794
				const struct path *path,
E
Eric Paris 已提交
1795 1796
				u32 av)
{
1797
	struct inode *inode = d_backing_inode(path->dentry);
E
Eric Paris 已提交
1798 1799
	struct common_audit_data ad;

1800
	ad.type = LSM_AUDIT_DATA_PATH;
E
Eric Paris 已提交
1801
	ad.u.path = *path;
1802
	__inode_security_revalidate(inode, path->dentry, true);
1803
	return inode_has_perm(cred, inode, av, &ad);
L
Linus Torvalds 已提交
1804 1805
}

1806 1807 1808 1809 1810 1811 1812
/* Same as path_has_perm, but uses the inode from the file struct. */
static inline int file_path_has_perm(const struct cred *cred,
				     struct file *file,
				     u32 av)
{
	struct common_audit_data ad;

1813 1814
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
1815
	return inode_has_perm(cred, file_inode(file), av, &ad);
1816 1817
}

1818 1819 1820 1821
#ifdef CONFIG_BPF_SYSCALL
static int bpf_fd_pass(struct file *file, u32 sid);
#endif

L
Linus Torvalds 已提交
1822 1823 1824 1825 1826 1827 1828 1829
/* Check whether a task can use an open file descriptor to
   access an inode in a given way.  Check access to the
   descriptor itself, and then use dentry_has_perm to
   check a particular permission to the file.
   Access to the descriptor is implicitly granted if it
   has the same SID as the process.  If av is zero, then
   access to the file is not checked, e.g. for cases
   where only the descriptor is affected like seek. */
1830 1831 1832
static int file_has_perm(const struct cred *cred,
			 struct file *file,
			 u32 av)
L
Linus Torvalds 已提交
1833 1834
{
	struct file_security_struct *fsec = file->f_security;
A
Al Viro 已提交
1835
	struct inode *inode = file_inode(file);
1836
	struct common_audit_data ad;
1837
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1838 1839
	int rc;

1840 1841
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
L
Linus Torvalds 已提交
1842

1843 1844
	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid,
L
Linus Torvalds 已提交
1845 1846 1847 1848
				  SECCLASS_FD,
				  FD__USE,
				  &ad);
		if (rc)
1849
			goto out;
L
Linus Torvalds 已提交
1850 1851
	}

1852 1853 1854 1855 1856 1857
#ifdef CONFIG_BPF_SYSCALL
	rc = bpf_fd_pass(file, cred_sid(cred));
	if (rc)
		return rc;
#endif

L
Linus Torvalds 已提交
1858
	/* av is zero if only checking access to the descriptor. */
1859
	rc = 0;
L
Linus Torvalds 已提交
1860
	if (av)
1861
		rc = inode_has_perm(cred, inode, av, &ad);
L
Linus Torvalds 已提交
1862

1863 1864
out:
	return rc;
L
Linus Torvalds 已提交
1865 1866
}

1867 1868 1869
/*
 * Determine the label for an inode that might be unioned.
 */
1870 1871 1872 1873 1874
static int
selinux_determine_inode_label(const struct task_security_struct *tsec,
				 struct inode *dir,
				 const struct qstr *name, u16 tclass,
				 u32 *_new_isid)
1875 1876 1877 1878 1879 1880 1881 1882 1883 1884
{
	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;

	if ((sbsec->flags & SE_SBINITIALIZED) &&
	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
		*_new_isid = sbsec->mntpoint_sid;
	} else if ((sbsec->flags & SBLABEL_MNT) &&
		   tsec->create_sid) {
		*_new_isid = tsec->create_sid;
	} else {
1885
		const struct inode_security_struct *dsec = inode_security(dir);
1886 1887 1888 1889 1890 1891 1892
		return security_transition_sid(tsec->sid, dsec->sid, tclass,
					       name, _new_isid);
	}

	return 0;
}

L
Linus Torvalds 已提交
1893 1894 1895 1896 1897
/* Check whether a task can create a file. */
static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
1898
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
1899 1900
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
1901
	u32 sid, newsid;
1902
	struct common_audit_data ad;
L
Linus Torvalds 已提交
1903 1904
	int rc;

1905
	dsec = inode_security(dir);
L
Linus Torvalds 已提交
1906 1907
	sbsec = dir->i_sb->s_security;

1908 1909
	sid = tsec->sid;

1910
	ad.type = LSM_AUDIT_DATA_DENTRY;
1911
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1912

1913
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1914 1915 1916 1917 1918
			  DIR__ADD_NAME | DIR__SEARCH,
			  &ad);
	if (rc)
		return rc;

1919 1920
	rc = selinux_determine_inode_label(current_security(), dir,
					   &dentry->d_name, tclass, &newsid);
1921 1922
	if (rc)
		return rc;
L
Linus Torvalds 已提交
1923

1924
	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
L
Linus Torvalds 已提交
1925 1926 1927 1928 1929 1930 1931 1932
	if (rc)
		return rc;

	return avc_has_perm(newsid, sbsec->sid,
			    SECCLASS_FILESYSTEM,
			    FILESYSTEM__ASSOCIATE, &ad);
}

1933 1934 1935
#define MAY_LINK	0
#define MAY_UNLINK	1
#define MAY_RMDIR	2
L
Linus Torvalds 已提交
1936 1937 1938 1939 1940 1941 1942 1943

/* Check whether a task can link, unlink, or rmdir a file/directory. */
static int may_link(struct inode *dir,
		    struct dentry *dentry,
		    int kind)

{
	struct inode_security_struct *dsec, *isec;
1944
	struct common_audit_data ad;
1945
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1946 1947 1948
	u32 av;
	int rc;

1949 1950
	dsec = inode_security(dir);
	isec = backing_inode_security(dentry);
L
Linus Torvalds 已提交
1951

1952
	ad.type = LSM_AUDIT_DATA_DENTRY;
1953
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1954 1955 1956

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1957
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
	if (rc)
		return rc;

	switch (kind) {
	case MAY_LINK:
		av = FILE__LINK;
		break;
	case MAY_UNLINK:
		av = FILE__UNLINK;
		break;
	case MAY_RMDIR:
		av = DIR__RMDIR;
		break;
	default:
E
Eric Paris 已提交
1972 1973
		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
			__func__, kind);
L
Linus Torvalds 已提交
1974 1975 1976
		return 0;
	}

1977
	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
L
Linus Torvalds 已提交
1978 1979 1980 1981 1982 1983 1984 1985 1986
	return rc;
}

static inline int may_rename(struct inode *old_dir,
			     struct dentry *old_dentry,
			     struct inode *new_dir,
			     struct dentry *new_dentry)
{
	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1987
	struct common_audit_data ad;
1988
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1989 1990 1991 1992
	u32 av;
	int old_is_dir, new_is_dir;
	int rc;

1993 1994
	old_dsec = inode_security(old_dir);
	old_isec = backing_inode_security(old_dentry);
1995
	old_is_dir = d_is_dir(old_dentry);
1996
	new_dsec = inode_security(new_dir);
L
Linus Torvalds 已提交
1997

1998
	ad.type = LSM_AUDIT_DATA_DENTRY;
L
Linus Torvalds 已提交
1999

2000
	ad.u.dentry = old_dentry;
2001
	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
2002 2003 2004
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
2005
	rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
2006 2007 2008 2009
			  old_isec->sclass, FILE__RENAME, &ad);
	if (rc)
		return rc;
	if (old_is_dir && new_dir != old_dir) {
2010
		rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
2011 2012 2013 2014 2015
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

2016
	ad.u.dentry = new_dentry;
L
Linus Torvalds 已提交
2017
	av = DIR__ADD_NAME | DIR__SEARCH;
2018
	if (d_is_positive(new_dentry))
L
Linus Torvalds 已提交
2019
		av |= DIR__REMOVE_NAME;
2020
	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
2021 2022
	if (rc)
		return rc;
2023
	if (d_is_positive(new_dentry)) {
2024
		new_isec = backing_inode_security(new_dentry);
2025
		new_is_dir = d_is_dir(new_dentry);
2026
		rc = avc_has_perm(sid, new_isec->sid,
L
Linus Torvalds 已提交
2027 2028 2029 2030 2031 2032 2033 2034 2035 2036
				  new_isec->sclass,
				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
		if (rc)
			return rc;
	}

	return 0;
}

/* Check whether a task can perform a filesystem operation. */
2037
static int superblock_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
2038 2039
			       struct super_block *sb,
			       u32 perms,
2040
			       struct common_audit_data *ad)
L
Linus Torvalds 已提交
2041 2042
{
	struct superblock_security_struct *sbsec;
2043
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
2044 2045

	sbsec = sb->s_security;
2046
	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
L
Linus Torvalds 已提交
2047 2048 2049 2050 2051 2052 2053
}

/* Convert a Linux mode and permission mask to an access vector. */
static inline u32 file_mask_to_av(int mode, int mask)
{
	u32 av = 0;

A
Al Viro 已提交
2054
	if (!S_ISDIR(mode)) {
L
Linus Torvalds 已提交
2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076
		if (mask & MAY_EXEC)
			av |= FILE__EXECUTE;
		if (mask & MAY_READ)
			av |= FILE__READ;

		if (mask & MAY_APPEND)
			av |= FILE__APPEND;
		else if (mask & MAY_WRITE)
			av |= FILE__WRITE;

	} else {
		if (mask & MAY_EXEC)
			av |= DIR__SEARCH;
		if (mask & MAY_WRITE)
			av |= DIR__WRITE;
		if (mask & MAY_READ)
			av |= DIR__READ;
	}

	return av;
}

2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099
/* Convert a Linux file to an access vector. */
static inline u32 file_to_av(struct file *file)
{
	u32 av = 0;

	if (file->f_mode & FMODE_READ)
		av |= FILE__READ;
	if (file->f_mode & FMODE_WRITE) {
		if (file->f_flags & O_APPEND)
			av |= FILE__APPEND;
		else
			av |= FILE__WRITE;
	}
	if (!av) {
		/*
		 * Special file opened with flags 3 for ioctl-only use.
		 */
		av = FILE__IOCTL;
	}

	return av;
}

E
Eric Paris 已提交
2100
/*
2101
 * Convert a file to an access vector and include the correct open
E
Eric Paris 已提交
2102 2103
 * open permission.
 */
2104
static inline u32 open_file_to_av(struct file *file)
E
Eric Paris 已提交
2105
{
2106
	u32 av = file_to_av(file);
2107
	struct inode *inode = file_inode(file);
E
Eric Paris 已提交
2108

2109
	if (selinux_policycap_openperm && inode->i_sb->s_magic != SOCKFS_MAGIC)
2110 2111
		av |= FILE__OPEN;

E
Eric Paris 已提交
2112 2113 2114
	return av;
}

L
Linus Torvalds 已提交
2115 2116
/* Hook functions begin here. */

2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160
static int selinux_binder_set_context_mgr(struct task_struct *mgr)
{
	u32 mysid = current_sid();
	u32 mgrsid = task_sid(mgr);

	return avc_has_perm(mysid, mgrsid, SECCLASS_BINDER,
			    BINDER__SET_CONTEXT_MGR, NULL);
}

static int selinux_binder_transaction(struct task_struct *from,
				      struct task_struct *to)
{
	u32 mysid = current_sid();
	u32 fromsid = task_sid(from);
	u32 tosid = task_sid(to);
	int rc;

	if (mysid != fromsid) {
		rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER,
				  BINDER__IMPERSONATE, NULL);
		if (rc)
			return rc;
	}

	return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__CALL,
			    NULL);
}

static int selinux_binder_transfer_binder(struct task_struct *from,
					  struct task_struct *to)
{
	u32 fromsid = task_sid(from);
	u32 tosid = task_sid(to);

	return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER,
			    NULL);
}

static int selinux_binder_transfer_file(struct task_struct *from,
					struct task_struct *to,
					struct file *file)
{
	u32 sid = task_sid(to);
	struct file_security_struct *fsec = file->f_security;
2161
	struct dentry *dentry = file->f_path.dentry;
2162
	struct inode_security_struct *isec;
2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177
	struct common_audit_data ad;
	int rc;

	ad.type = LSM_AUDIT_DATA_PATH;
	ad.u.path = file->f_path;

	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid,
				  SECCLASS_FD,
				  FD__USE,
				  &ad);
		if (rc)
			return rc;
	}

2178 2179 2180 2181 2182 2183
#ifdef CONFIG_BPF_SYSCALL
	rc = bpf_fd_pass(file, sid);
	if (rc)
		return rc;
#endif

2184
	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2185 2186
		return 0;

2187
	isec = backing_inode_security(dentry);
2188 2189 2190 2191
	return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
			    &ad);
}

2192
static int selinux_ptrace_access_check(struct task_struct *child,
2193
				     unsigned int mode)
L
Linus Torvalds 已提交
2194
{
2195 2196 2197 2198
	u32 sid = current_sid();
	u32 csid = task_sid(child);

	if (mode & PTRACE_MODE_READ)
2199
		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
2200

2201
	return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2202 2203 2204 2205
}

static int selinux_ptrace_traceme(struct task_struct *parent)
{
2206 2207
	return avc_has_perm(task_sid(parent), current_sid(), SECCLASS_PROCESS,
			    PROCESS__PTRACE, NULL);
L
Linus Torvalds 已提交
2208 2209 2210
}

static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
2211
			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
L
Linus Torvalds 已提交
2212
{
2213 2214
	return avc_has_perm(current_sid(), task_sid(target), SECCLASS_PROCESS,
			    PROCESS__GETCAP, NULL);
L
Linus Torvalds 已提交
2215 2216
}

D
David Howells 已提交
2217 2218 2219 2220
static int selinux_capset(struct cred *new, const struct cred *old,
			  const kernel_cap_t *effective,
			  const kernel_cap_t *inheritable,
			  const kernel_cap_t *permitted)
L
Linus Torvalds 已提交
2221
{
2222 2223
	return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
			    PROCESS__SETCAP, NULL);
L
Linus Torvalds 已提交
2224 2225
}

2226 2227 2228 2229 2230 2231 2232 2233 2234 2235
/*
 * (This comment used to live with the selinux_task_setuid hook,
 * which was removed).
 *
 * Since setuid only affects the current process, and since the SELinux
 * controls are not based on the Linux identity attributes, SELinux does not
 * need to control this operation.  However, SELinux does control the use of
 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
 */

2236 2237
static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
			   int cap, int audit)
L
Linus Torvalds 已提交
2238
{
2239
	return cred_has_capability(cred, cap, audit, ns == &init_user_ns);
L
Linus Torvalds 已提交
2240 2241 2242 2243
}

static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
{
2244
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2245 2246 2247 2248 2249 2250
	int rc = 0;

	if (!sb)
		return 0;

	switch (cmds) {
2251 2252 2253 2254 2255
	case Q_SYNC:
	case Q_QUOTAON:
	case Q_QUOTAOFF:
	case Q_SETINFO:
	case Q_SETQUOTA:
2256
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2257 2258 2259 2260
		break;
	case Q_GETFMT:
	case Q_GETINFO:
	case Q_GETQUOTA:
2261
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2262 2263 2264 2265
		break;
	default:
		rc = 0;  /* let the kernel handle invalid cmds */
		break;
L
Linus Torvalds 已提交
2266 2267 2268 2269 2270 2271
	}
	return rc;
}

static int selinux_quota_on(struct dentry *dentry)
{
2272 2273
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2274
	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
L
Linus Torvalds 已提交
2275 2276
}

2277
static int selinux_syslog(int type)
L
Linus Torvalds 已提交
2278 2279
{
	switch (type) {
2280 2281
	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
2282 2283
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2284 2285 2286 2287
	case SYSLOG_ACTION_CONSOLE_OFF:	/* Disable logging to console */
	case SYSLOG_ACTION_CONSOLE_ON:	/* Enable logging to console */
	/* Set level of messages printed to console */
	case SYSLOG_ACTION_CONSOLE_LEVEL:
2288 2289 2290
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
				    NULL);
L
Linus Torvalds 已提交
2291
	}
2292 2293 2294
	/* All other syslog types */
	return avc_has_perm(current_sid(), SECINITSID_KERNEL,
			    SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
L
Linus Torvalds 已提交
2295 2296 2297 2298 2299 2300 2301 2302 2303 2304
}

/*
 * Check that a process has enough memory to allocate a new virtual
 * mapping. 0 means there is enough memory for the allocation to
 * succeed and -ENOMEM implies there is not.
 *
 * Do not audit the selinux permission check, as this is applied to all
 * processes that allocate mappings.
 */
2305
static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
L
Linus Torvalds 已提交
2306 2307 2308
{
	int rc, cap_sys_admin = 0;

C
Casey Schaufler 已提交
2309
	rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2310
				 SECURITY_CAP_NOAUDIT, true);
L
Linus Torvalds 已提交
2311 2312 2313
	if (rc == 0)
		cap_sys_admin = 1;

C
Casey Schaufler 已提交
2314
	return cap_sys_admin;
L
Linus Torvalds 已提交
2315 2316 2317 2318
}

/* binprm security operations */

2319
static u32 ptrace_parent_sid(void)
2320 2321 2322 2323 2324
{
	u32 sid = 0;
	struct task_struct *tracer;

	rcu_read_lock();
2325
	tracer = ptrace_parent(current);
2326 2327 2328 2329 2330 2331 2332
	if (tracer)
		sid = task_sid(tracer);
	rcu_read_unlock();

	return sid;
}

2333 2334 2335 2336 2337
static int check_nnp_nosuid(const struct linux_binprm *bprm,
			    const struct task_security_struct *old_tsec,
			    const struct task_security_struct *new_tsec)
{
	int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2338
	int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2339
	int rc;
2340
	u32 av;
2341 2342 2343 2344 2345 2346 2347 2348

	if (!nnp && !nosuid)
		return 0; /* neither NNP nor nosuid */

	if (new_tsec->sid == old_tsec->sid)
		return 0; /* No change in credentials */

	/*
2349 2350 2351 2352
	 * If the policy enables the nnp_nosuid_transition policy capability,
	 * then we permit transitions under NNP or nosuid if the
	 * policy allows the corresponding permission between
	 * the old and new contexts.
2353
	 */
2354 2355
	if (selinux_policycap_nnp_nosuid_transition) {
		av = 0;
2356
		if (nnp)
2357 2358 2359 2360 2361 2362 2363
			av |= PROCESS2__NNP_TRANSITION;
		if (nosuid)
			av |= PROCESS2__NOSUID_TRANSITION;
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
				  SECCLASS_PROCESS2, av, NULL);
		if (!rc)
			return 0;
2364
	}
2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382

	/*
	 * We also permit NNP or nosuid transitions to bounded SIDs,
	 * i.e. SIDs that are guaranteed to only be allowed a subset
	 * of the permissions of the current SID.
	 */
	rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
	if (!rc)
		return 0;

	/*
	 * On failure, preserve the errno values for NNP vs nosuid.
	 * NNP:  Operation not permitted for caller.
	 * nosuid:  Permission denied to file.
	 */
	if (nnp)
		return -EPERM;
	return -EACCES;
2383 2384
}

2385
static int selinux_bprm_set_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2386
{
2387 2388
	const struct task_security_struct *old_tsec;
	struct task_security_struct *new_tsec;
L
Linus Torvalds 已提交
2389
	struct inode_security_struct *isec;
2390
	struct common_audit_data ad;
A
Al Viro 已提交
2391
	struct inode *inode = file_inode(bprm->file);
L
Linus Torvalds 已提交
2392 2393
	int rc;

2394 2395
	/* SELinux context only depends on initial program or script and not
	 * the script interpreter */
2396
	if (bprm->called_set_creds)
L
Linus Torvalds 已提交
2397 2398
		return 0;

2399 2400
	old_tsec = current_security();
	new_tsec = bprm->cred->security;
2401
	isec = inode_security(inode);
L
Linus Torvalds 已提交
2402 2403

	/* Default to the current task SID. */
2404 2405
	new_tsec->sid = old_tsec->sid;
	new_tsec->osid = old_tsec->sid;
L
Linus Torvalds 已提交
2406

2407
	/* Reset fs, key, and sock SIDs on execve. */
2408 2409 2410
	new_tsec->create_sid = 0;
	new_tsec->keycreate_sid = 0;
	new_tsec->sockcreate_sid = 0;
L
Linus Torvalds 已提交
2411

2412 2413
	if (old_tsec->exec_sid) {
		new_tsec->sid = old_tsec->exec_sid;
L
Linus Torvalds 已提交
2414
		/* Reset exec SID on execve. */
2415
		new_tsec->exec_sid = 0;
2416

2417 2418 2419 2420
		/* Fail on NNP or nosuid if not an allowed transition. */
		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
		if (rc)
			return rc;
L
Linus Torvalds 已提交
2421 2422
	} else {
		/* Check for a default transition on this program. */
2423
		rc = security_transition_sid(old_tsec->sid, isec->sid,
2424 2425
					     SECCLASS_PROCESS, NULL,
					     &new_tsec->sid);
L
Linus Torvalds 已提交
2426 2427
		if (rc)
			return rc;
2428 2429 2430 2431 2432 2433 2434 2435

		/*
		 * Fallback to old SID on NNP or nosuid if not an allowed
		 * transition.
		 */
		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
		if (rc)
			new_tsec->sid = old_tsec->sid;
L
Linus Torvalds 已提交
2436 2437
	}

2438 2439
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = bprm->file;
L
Linus Torvalds 已提交
2440

2441 2442
	if (new_tsec->sid == old_tsec->sid) {
		rc = avc_has_perm(old_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2443 2444 2445 2446 2447
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		/* Check permissions for the transition. */
2448
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
L
Linus Torvalds 已提交
2449 2450 2451 2452
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

2453
		rc = avc_has_perm(new_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2454 2455 2456 2457
				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
		if (rc)
			return rc;

2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468
		/* Check for shared state */
		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
					  SECCLASS_PROCESS, PROCESS__SHARE,
					  NULL);
			if (rc)
				return -EPERM;
		}

		/* Make sure that anyone attempting to ptrace over a task that
		 * changes its SID has the appropriate permit */
2469
		if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2470
			u32 ptsid = ptrace_parent_sid();
2471 2472 2473 2474 2475 2476 2477 2478
			if (ptsid != 0) {
				rc = avc_has_perm(ptsid, new_tsec->sid,
						  SECCLASS_PROCESS,
						  PROCESS__PTRACE, NULL);
				if (rc)
					return -EPERM;
			}
		}
L
Linus Torvalds 已提交
2479

2480 2481
		/* Clear any possibly unsafe personality bits on exec: */
		bprm->per_clear |= PER_CLEAR_ON_SETID;
2482

L
Linus Torvalds 已提交
2483 2484 2485
		/* Enable secure mode for SIDs transitions unless
		   the noatsecure permission is granted between
		   the two SIDs, i.e. ahp returns 0. */
2486 2487 2488 2489
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
				  SECCLASS_PROCESS, PROCESS__NOATSECURE,
				  NULL);
		bprm->secureexec |= !!rc;
L
Linus Torvalds 已提交
2490 2491
	}

2492
	return 0;
L
Linus Torvalds 已提交
2493 2494
}

A
Al Viro 已提交
2495 2496 2497 2498 2499
static int match_file(const void *p, struct file *file, unsigned fd)
{
	return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
}

L
Linus Torvalds 已提交
2500
/* Derived from fs/exec.c:flush_old_files. */
2501 2502
static inline void flush_unauthorized_files(const struct cred *cred,
					    struct files_struct *files)
L
Linus Torvalds 已提交
2503 2504
{
	struct file *file, *devnull = NULL;
2505
	struct tty_struct *tty;
2506
	int drop_tty = 0;
A
Al Viro 已提交
2507
	unsigned n;
L
Linus Torvalds 已提交
2508

2509
	tty = get_current_tty();
L
Linus Torvalds 已提交
2510
	if (tty) {
P
Peter Hurley 已提交
2511
		spin_lock(&tty->files_lock);
2512
		if (!list_empty(&tty->tty_files)) {
N
Nick Piggin 已提交
2513
			struct tty_file_private *file_priv;
2514

L
Linus Torvalds 已提交
2515
			/* Revalidate access to controlling tty.
2516 2517 2518 2519
			   Use file_path_has_perm on the tty path directly
			   rather than using file_has_perm, as this particular
			   open file may belong to another process and we are
			   only interested in the inode-based check here. */
N
Nick Piggin 已提交
2520 2521 2522
			file_priv = list_first_entry(&tty->tty_files,
						struct tty_file_private, list);
			file = file_priv->file;
2523
			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2524
				drop_tty = 1;
L
Linus Torvalds 已提交
2525
		}
P
Peter Hurley 已提交
2526
		spin_unlock(&tty->files_lock);
A
Alan Cox 已提交
2527
		tty_kref_put(tty);
L
Linus Torvalds 已提交
2528
	}
2529 2530 2531
	/* Reset controlling tty. */
	if (drop_tty)
		no_tty();
L
Linus Torvalds 已提交
2532 2533

	/* Revalidate access to inherited open files. */
A
Al Viro 已提交
2534 2535 2536
	n = iterate_fd(files, 0, match_file, cred);
	if (!n) /* none found? */
		return;
L
Linus Torvalds 已提交
2537

A
Al Viro 已提交
2538
	devnull = dentry_open(&selinux_null, O_RDWR, cred);
A
Al Viro 已提交
2539 2540 2541 2542 2543 2544 2545
	if (IS_ERR(devnull))
		devnull = NULL;
	/* replace all the matching ones with this */
	do {
		replace_fd(n - 1, devnull, 0);
	} while ((n = iterate_fd(files, n, match_file, cred)) != 0);
	if (devnull)
A
Al Viro 已提交
2546
		fput(devnull);
L
Linus Torvalds 已提交
2547 2548
}

2549 2550 2551 2552
/*
 * Prepare a process for imminent new credential changes due to exec
 */
static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2553
{
2554 2555 2556
	struct task_security_struct *new_tsec;
	struct rlimit *rlim, *initrlim;
	int rc, i;
D
David Howells 已提交
2557

2558 2559 2560
	new_tsec = bprm->cred->security;
	if (new_tsec->sid == new_tsec->osid)
		return;
L
Linus Torvalds 已提交
2561

2562 2563
	/* Close files for which the new task SID is not authorized. */
	flush_unauthorized_files(bprm->cred, current->files);
R
Roland McGrath 已提交
2564

2565 2566
	/* Always clear parent death signal on SID transitions. */
	current->pdeath_signal = 0;
R
Roland McGrath 已提交
2567

2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580
	/* Check whether the new SID can inherit resource limits from the old
	 * SID.  If not, reset all soft limits to the lower of the current
	 * task's hard limit and the init task's soft limit.
	 *
	 * Note that the setting of hard limits (even to lower them) can be
	 * controlled by the setrlimit check.  The inclusion of the init task's
	 * soft limit into the computation is to avoid resetting soft limits
	 * higher than the default soft limit for cases where the default is
	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
	 */
	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
			  PROCESS__RLIMITINH, NULL);
	if (rc) {
2581 2582
		/* protect against do_prlimit() */
		task_lock(current);
2583 2584 2585 2586
		for (i = 0; i < RLIM_NLIMITS; i++) {
			rlim = current->signal->rlim + i;
			initrlim = init_task.signal->rlim + i;
			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
L
Linus Torvalds 已提交
2587
		}
2588
		task_unlock(current);
2589 2590
		if (IS_ENABLED(CONFIG_POSIX_TIMERS))
			update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
L
Linus Torvalds 已提交
2591 2592 2593 2594
	}
}

/*
2595 2596
 * Clean up the process immediately after the installation of new credentials
 * due to exec
L
Linus Torvalds 已提交
2597
 */
2598
static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2599
{
2600
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
2601
	struct itimerval itimer;
2602
	u32 osid, sid;
L
Linus Torvalds 已提交
2603 2604
	int rc, i;

2605 2606 2607 2608
	osid = tsec->osid;
	sid = tsec->sid;

	if (sid == osid)
L
Linus Torvalds 已提交
2609 2610
		return;

2611 2612 2613 2614 2615 2616 2617 2618
	/* Check whether the new SID can inherit signal state from the old SID.
	 * If not, clear itimers to avoid subsequent signal generation and
	 * flush and unblock signals.
	 *
	 * This must occur _after_ the task SID has been updated so that any
	 * kill done after the flush will be checked against the new SID.
	 */
	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
L
Linus Torvalds 已提交
2619
	if (rc) {
2620 2621 2622 2623 2624
		if (IS_ENABLED(CONFIG_POSIX_TIMERS)) {
			memset(&itimer, 0, sizeof itimer);
			for (i = 0; i < 3; i++)
				do_setitimer(i, &itimer, NULL);
		}
L
Linus Torvalds 已提交
2625
		spin_lock_irq(&current->sighand->siglock);
2626 2627 2628
		if (!fatal_signal_pending(current)) {
			flush_sigqueue(&current->pending);
			flush_sigqueue(&current->signal->shared_pending);
2629 2630
			flush_signal_handlers(current, 1);
			sigemptyset(&current->blocked);
2631
			recalc_sigpending();
2632
		}
L
Linus Torvalds 已提交
2633 2634 2635
		spin_unlock_irq(&current->sighand->siglock);
	}

2636 2637
	/* Wake up the parent if it is waiting so that it can recheck
	 * wait permission to the new task SID. */
2638
	read_lock(&tasklist_lock);
2639
	__wake_up_parent(current, current->real_parent);
2640
	read_unlock(&tasklist_lock);
L
Linus Torvalds 已提交
2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664
}

/* superblock security operations */

static int selinux_sb_alloc_security(struct super_block *sb)
{
	return superblock_alloc_security(sb);
}

static void selinux_sb_free_security(struct super_block *sb)
{
	superblock_free_security(sb);
}

static inline int match_prefix(char *prefix, int plen, char *option, int olen)
{
	if (plen > olen)
		return 0;

	return !memcmp(prefix, option, plen);
}

static inline int selinux_option(char *option, int len)
{
2665 2666 2667
	return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
		match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
		match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2668 2669
		match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
		match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
L
Linus Torvalds 已提交
2670 2671 2672 2673 2674 2675 2676
}

static inline void take_option(char **to, char *from, int *first, int len)
{
	if (!*first) {
		**to = ',';
		*to += 1;
2677
	} else
L
Linus Torvalds 已提交
2678 2679 2680 2681 2682
		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}

2683 2684
static inline void take_selinux_option(char **to, char *from, int *first,
				       int len)
2685 2686 2687 2688 2689 2690
{
	int current_size = 0;

	if (!*first) {
		**to = '|';
		*to += 1;
2691
	} else
2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703
		*first = 0;

	while (current_size < len) {
		if (*from != '"') {
			**to = *from;
			*to += 1;
		}
		from += 1;
		current_size += 1;
	}
}

2704
static int selinux_sb_copy_data(char *orig, char *copy)
L
Linus Torvalds 已提交
2705 2706 2707 2708
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_curr, *in_end;
	char *sec_curr, *nosec_save, *nosec;
2709
	int open_quote = 0;
L
Linus Torvalds 已提交
2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724

	in_curr = orig;
	sec_curr = copy;

	nosec = (char *)get_zeroed_page(GFP_KERNEL);
	if (!nosec) {
		rc = -ENOMEM;
		goto out;
	}

	nosec_save = nosec;
	fnosec = fsec = 1;
	in_save = in_end = orig;

	do {
2725 2726 2727 2728
		if (*in_end == '"')
			open_quote = !open_quote;
		if ((*in_end == ',' && open_quote == 0) ||
				*in_end == '\0') {
L
Linus Torvalds 已提交
2729 2730 2731
			int len = in_end - in_curr;

			if (selinux_option(in_curr, len))
2732
				take_selinux_option(&sec_curr, in_curr, &fsec, len);
L
Linus Torvalds 已提交
2733 2734 2735 2736 2737 2738 2739
			else
				take_option(&nosec, in_curr, &fnosec, len);

			in_curr = in_end + 1;
		}
	} while (*in_end++);

2740
	strcpy(in_save, nosec_save);
2741
	free_page((unsigned long)nosec_save);
L
Linus Torvalds 已提交
2742 2743 2744 2745
out:
	return rc;
}

2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779
static int selinux_sb_remount(struct super_block *sb, void *data)
{
	int rc, i, *flags;
	struct security_mnt_opts opts;
	char *secdata, **mount_options;
	struct superblock_security_struct *sbsec = sb->s_security;

	if (!(sbsec->flags & SE_SBINITIALIZED))
		return 0;

	if (!data)
		return 0;

	if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
		return 0;

	security_init_mnt_opts(&opts);
	secdata = alloc_secdata();
	if (!secdata)
		return -ENOMEM;
	rc = selinux_sb_copy_data(data, secdata);
	if (rc)
		goto out_free_secdata;

	rc = selinux_parse_opts_str(secdata, &opts);
	if (rc)
		goto out_free_secdata;

	mount_options = opts.mnt_opts;
	flags = opts.mnt_opts_flags;

	for (i = 0; i < opts.num_mnt_opts; i++) {
		u32 sid;

2780
		if (flags[i] == SBLABEL_MNT)
2781
			continue;
2782
		rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL);
2783
		if (rc) {
2784
			printk(KERN_WARNING "SELinux: security_context_str_to_sid"
2785 2786
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, sb->s_type->name, rc);
2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800
			goto out_free_opts;
		}
		rc = -EINVAL;
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
				goto out_bad_option;
			break;
		case CONTEXT_MNT:
			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
				goto out_bad_option;
			break;
		case ROOTCONTEXT_MNT: {
			struct inode_security_struct *root_isec;
2801
			root_isec = backing_inode_security(sb->s_root);
2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823

			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
				goto out_bad_option;
			break;
		}
		case DEFCONTEXT_MNT:
			if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
				goto out_bad_option;
			break;
		default:
			goto out_free_opts;
		}
	}

	rc = 0;
out_free_opts:
	security_free_mnt_opts(&opts);
out_free_secdata:
	free_secdata(secdata);
	return rc;
out_bad_option:
	printk(KERN_WARNING "SELinux: unable to change security options "
2824 2825
	       "during remount (dev %s, type=%s)\n", sb->s_id,
	       sb->s_type->name);
2826 2827 2828
	goto out_free_opts;
}

2829
static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
L
Linus Torvalds 已提交
2830
{
2831
	const struct cred *cred = current_cred();
2832
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2833 2834 2835 2836 2837 2838
	int rc;

	rc = superblock_doinit(sb, data);
	if (rc)
		return rc;

2839 2840 2841 2842
	/* Allow all mounts performed by the kernel */
	if (flags & MS_KERNMOUNT)
		return 0;

2843
	ad.type = LSM_AUDIT_DATA_DENTRY;
2844
	ad.u.dentry = sb->s_root;
2845
	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
L
Linus Torvalds 已提交
2846 2847
}

2848
static int selinux_sb_statfs(struct dentry *dentry)
L
Linus Torvalds 已提交
2849
{
2850
	const struct cred *cred = current_cred();
2851
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2852

2853
	ad.type = LSM_AUDIT_DATA_DENTRY;
2854
	ad.u.dentry = dentry->d_sb->s_root;
2855
	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
L
Linus Torvalds 已提交
2856 2857
}

A
Al Viro 已提交
2858
static int selinux_mount(const char *dev_name,
A
Al Viro 已提交
2859
			 const struct path *path,
A
Al Viro 已提交
2860
			 const char *type,
2861 2862
			 unsigned long flags,
			 void *data)
L
Linus Torvalds 已提交
2863
{
2864
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2865 2866

	if (flags & MS_REMOUNT)
2867
		return superblock_has_perm(cred, path->dentry->d_sb,
2868
					   FILESYSTEM__REMOUNT, NULL);
L
Linus Torvalds 已提交
2869
	else
E
Eric Paris 已提交
2870
		return path_has_perm(cred, path, FILE__MOUNTON);
L
Linus Torvalds 已提交
2871 2872 2873 2874
}

static int selinux_umount(struct vfsmount *mnt, int flags)
{
2875
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2876

2877
	return superblock_has_perm(cred, mnt->mnt_sb,
2878
				   FILESYSTEM__UNMOUNT, NULL);
L
Linus Torvalds 已提交
2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892
}

/* inode security operations */

static int selinux_inode_alloc_security(struct inode *inode)
{
	return inode_alloc_security(inode);
}

static void selinux_inode_free_security(struct inode *inode)
{
	inode_free_security(inode);
}

2893
static int selinux_dentry_init_security(struct dentry *dentry, int mode,
A
Al Viro 已提交
2894
					const struct qstr *name, void **ctx,
2895 2896 2897 2898 2899
					u32 *ctxlen)
{
	u32 newsid;
	int rc;

2900 2901
	rc = selinux_determine_inode_label(current_security(),
					   d_inode(dentry->d_parent), name,
2902 2903 2904 2905
					   inode_mode_to_security_class(mode),
					   &newsid);
	if (rc)
		return rc;
2906 2907 2908 2909

	return security_sid_to_context(newsid, (char **)ctx, ctxlen);
}

2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930
static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
					  struct qstr *name,
					  const struct cred *old,
					  struct cred *new)
{
	u32 newsid;
	int rc;
	struct task_security_struct *tsec;

	rc = selinux_determine_inode_label(old->security,
					   d_inode(dentry->d_parent), name,
					   inode_mode_to_security_class(mode),
					   &newsid);
	if (rc)
		return rc;

	tsec = new->security;
	tsec->create_sid = newsid;
	return 0;
}

2931
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2932 2933
				       const struct qstr *qstr,
				       const char **name,
2934
				       void **value, size_t *len)
2935
{
2936
	const struct task_security_struct *tsec = current_security();
2937
	struct superblock_security_struct *sbsec;
2938
	u32 sid, newsid, clen;
2939
	int rc;
2940
	char *context;
2941 2942 2943

	sbsec = dir->i_sb->s_security;

2944 2945 2946
	sid = tsec->sid;
	newsid = tsec->create_sid;

2947
	rc = selinux_determine_inode_label(current_security(),
2948 2949 2950 2951 2952
		dir, qstr,
		inode_mode_to_security_class(inode->i_mode),
		&newsid);
	if (rc)
		return rc;
2953

2954
	/* Possibly defer initialization to selinux_complete_init. */
2955
	if (sbsec->flags & SE_SBINITIALIZED) {
2956 2957 2958
		struct inode_security_struct *isec = inode->i_security;
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		isec->sid = newsid;
2959
		isec->initialized = LABEL_INITIALIZED;
2960
	}
2961

2962
	if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
2963 2964
		return -EOPNOTSUPP;

2965 2966
	if (name)
		*name = XATTR_SELINUX_SUFFIX;
2967

2968
	if (value && len) {
2969
		rc = security_sid_to_context_force(newsid, &context, &clen);
2970
		if (rc)
2971 2972 2973
			return rc;
		*value = context;
		*len = clen;
2974 2975 2976 2977 2978
	}

	return 0;
}

A
Al Viro 已提交
2979
static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998
{
	return may_create(dir, dentry, SECCLASS_FILE);
}

static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
{
	return may_link(dir, old_dentry, MAY_LINK);
}

static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
{
	return may_link(dir, dentry, MAY_UNLINK);
}

static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
{
	return may_create(dir, dentry, SECCLASS_LNK_FILE);
}

2999
static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
L
Linus Torvalds 已提交
3000 3001 3002 3003 3004 3005 3006 3007 3008
{
	return may_create(dir, dentry, SECCLASS_DIR);
}

static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
{
	return may_link(dir, dentry, MAY_RMDIR);
}

A
Al Viro 已提交
3009
static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
L
Linus Torvalds 已提交
3010 3011 3012 3013 3014
{
	return may_create(dir, dentry, inode_mode_to_security_class(mode));
}

static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
3015
				struct inode *new_inode, struct dentry *new_dentry)
L
Linus Torvalds 已提交
3016 3017 3018 3019 3020 3021
{
	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
}

static int selinux_inode_readlink(struct dentry *dentry)
{
3022 3023
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
3024
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
3025 3026
}

3027 3028
static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
				     bool rcu)
L
Linus Torvalds 已提交
3029
{
3030
	const struct cred *cred = current_cred();
3031 3032 3033
	struct common_audit_data ad;
	struct inode_security_struct *isec;
	u32 sid;
L
Linus Torvalds 已提交
3034

3035 3036 3037 3038 3039
	validate_creds(cred);

	ad.type = LSM_AUDIT_DATA_DENTRY;
	ad.u.dentry = dentry;
	sid = cred_sid(cred);
3040 3041 3042
	isec = inode_security_rcu(inode, rcu);
	if (IS_ERR(isec))
		return PTR_ERR(isec);
3043 3044 3045

	return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad,
				  rcu ? MAY_NOT_BLOCK : 0);
L
Linus Torvalds 已提交
3046 3047
}

3048 3049
static noinline int audit_inode_permission(struct inode *inode,
					   u32 perms, u32 audited, u32 denied,
3050
					   int result,
3051
					   unsigned flags)
L
Linus Torvalds 已提交
3052
{
3053
	struct common_audit_data ad;
3054 3055 3056
	struct inode_security_struct *isec = inode->i_security;
	int rc;

3057
	ad.type = LSM_AUDIT_DATA_INODE;
3058 3059 3060
	ad.u.inode = inode;

	rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
3061
			    audited, denied, result, &ad, flags);
3062 3063 3064 3065 3066
	if (rc)
		return rc;
	return 0;
}

3067
static int selinux_inode_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
3068
{
3069
	const struct cred *cred = current_cred();
3070 3071
	u32 perms;
	bool from_access;
3072
	unsigned flags = mask & MAY_NOT_BLOCK;
3073 3074 3075 3076 3077
	struct inode_security_struct *isec;
	u32 sid;
	struct av_decision avd;
	int rc, rc2;
	u32 audited, denied;
L
Linus Torvalds 已提交
3078

3079
	from_access = mask & MAY_ACCESS;
3080 3081
	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);

3082 3083
	/* No permission to check.  Existence test. */
	if (!mask)
L
Linus Torvalds 已提交
3084 3085
		return 0;

3086
	validate_creds(cred);
3087

3088 3089
	if (unlikely(IS_PRIVATE(inode)))
		return 0;
3090 3091 3092

	perms = file_mask_to_av(inode->i_mode, mask);

3093
	sid = cred_sid(cred);
3094 3095 3096
	isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK);
	if (IS_ERR(isec))
		return PTR_ERR(isec);
3097 3098 3099 3100 3101 3102 3103 3104

	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
	audited = avc_audit_required(perms, &avd, rc,
				     from_access ? FILE__AUDIT_ACCESS : 0,
				     &denied);
	if (likely(!audited))
		return rc;

3105
	rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
3106 3107 3108
	if (rc2)
		return rc2;
	return rc;
L
Linus Torvalds 已提交
3109 3110 3111 3112
}

static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
3113
	const struct cred *cred = current_cred();
3114
	struct inode *inode = d_backing_inode(dentry);
3115
	unsigned int ia_valid = iattr->ia_valid;
3116
	__u32 av = FILE__WRITE;
L
Linus Torvalds 已提交
3117

3118 3119 3120 3121 3122 3123 3124
	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
	if (ia_valid & ATTR_FORCE) {
		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
			      ATTR_FORCE);
		if (!ia_valid)
			return 0;
	}
L
Linus Torvalds 已提交
3125

3126 3127
	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
E
Eric Paris 已提交
3128
		return dentry_has_perm(cred, dentry, FILE__SETATTR);
L
Linus Torvalds 已提交
3129

3130 3131 3132 3133
	if (selinux_policycap_openperm &&
	    inode->i_sb->s_magic != SOCKFS_MAGIC &&
	    (ia_valid & ATTR_SIZE) &&
	    !(ia_valid & ATTR_FILE))
3134 3135 3136
		av |= FILE__OPEN;

	return dentry_has_perm(cred, dentry, av);
L
Linus Torvalds 已提交
3137 3138
}

3139
static int selinux_inode_getattr(const struct path *path)
L
Linus Torvalds 已提交
3140
{
3141
	return path_has_perm(current_cred(), path, FILE__GETATTR);
L
Linus Torvalds 已提交
3142 3143
}

3144
static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
3145
{
3146 3147
	const struct cred *cred = current_cred();

3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161
	if (!strncmp(name, XATTR_SECURITY_PREFIX,
		     sizeof XATTR_SECURITY_PREFIX - 1)) {
		if (!strcmp(name, XATTR_NAME_CAPS)) {
			if (!capable(CAP_SETFCAP))
				return -EPERM;
		} else if (!capable(CAP_SYS_ADMIN)) {
			/* A different attribute in the security namespace.
			   Restrict to administrator. */
			return -EPERM;
		}
	}

	/* Not an attribute we recognize, so just check the
	   ordinary setattr permission. */
E
Eric Paris 已提交
3162
	return dentry_has_perm(cred, dentry, FILE__SETATTR);
3163 3164
}

3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176
static bool has_cap_mac_admin(bool audit)
{
	const struct cred *cred = current_cred();
	int cap_audit = audit ? SECURITY_CAP_AUDIT : SECURITY_CAP_NOAUDIT;

	if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, cap_audit))
		return false;
	if (cred_has_capability(cred, CAP_MAC_ADMIN, cap_audit, true))
		return false;
	return true;
}

3177 3178
static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
				  const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
3179
{
3180
	struct inode *inode = d_backing_inode(dentry);
3181
	struct inode_security_struct *isec;
L
Linus Torvalds 已提交
3182
	struct superblock_security_struct *sbsec;
3183
	struct common_audit_data ad;
3184
	u32 newsid, sid = current_sid();
L
Linus Torvalds 已提交
3185 3186
	int rc = 0;

3187 3188
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
3189 3190

	sbsec = inode->i_sb->s_security;
3191
	if (!(sbsec->flags & SBLABEL_MNT))
L
Linus Torvalds 已提交
3192 3193
		return -EOPNOTSUPP;

3194
	if (!inode_owner_or_capable(inode))
L
Linus Torvalds 已提交
3195 3196
		return -EPERM;

3197
	ad.type = LSM_AUDIT_DATA_DENTRY;
3198
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
3199

3200
	isec = backing_inode_security(dentry);
3201
	rc = avc_has_perm(sid, isec->sid, isec->sclass,
L
Linus Torvalds 已提交
3202 3203 3204 3205
			  FILE__RELABELFROM, &ad);
	if (rc)
		return rc;

3206
	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
3207
	if (rc == -EINVAL) {
3208
		if (!has_cap_mac_admin(true)) {
3209 3210 3211 3212 3213 3214
			struct audit_buffer *ab;
			size_t audit_size;
			const char *str;

			/* We strip a nul only if it is at the end, otherwise the
			 * context contains a nul and we should audit that */
3215 3216 3217 3218 3219 3220 3221 3222 3223 3224
			if (value) {
				str = value;
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
			} else {
				str = "";
				audit_size = 0;
			}
3225 3226 3227 3228 3229
			ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
			audit_log_format(ab, "op=setxattr invalid_context=");
			audit_log_n_untrustedstring(ab, value, audit_size);
			audit_log_end(ab);

3230
			return rc;
3231
		}
3232 3233
		rc = security_context_to_sid_force(value, size, &newsid);
	}
L
Linus Torvalds 已提交
3234 3235 3236
	if (rc)
		return rc;

3237
	rc = avc_has_perm(sid, newsid, isec->sclass,
L
Linus Torvalds 已提交
3238 3239 3240 3241
			  FILE__RELABELTO, &ad);
	if (rc)
		return rc;

3242
	rc = security_validate_transition(isec->sid, newsid, sid,
3243
					  isec->sclass);
L
Linus Torvalds 已提交
3244 3245 3246 3247 3248 3249 3250 3251 3252 3253
	if (rc)
		return rc;

	return avc_has_perm(newsid,
			    sbsec->sid,
			    SECCLASS_FILESYSTEM,
			    FILESYSTEM__ASSOCIATE,
			    &ad);
}

3254
static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3255
					const void *value, size_t size,
3256
					int flags)
L
Linus Torvalds 已提交
3257
{
3258
	struct inode *inode = d_backing_inode(dentry);
3259
	struct inode_security_struct *isec;
L
Linus Torvalds 已提交
3260 3261 3262 3263 3264 3265 3266 3267
	u32 newsid;
	int rc;

	if (strcmp(name, XATTR_NAME_SELINUX)) {
		/* Not an attribute we recognize, so nothing to do. */
		return;
	}

3268
	rc = security_context_to_sid_force(value, size, &newsid);
L
Linus Torvalds 已提交
3269
	if (rc) {
3270 3271 3272
		printk(KERN_ERR "SELinux:  unable to map context to SID"
		       "for (%s, %lu), rc=%d\n",
		       inode->i_sb->s_id, inode->i_ino, -rc);
L
Linus Torvalds 已提交
3273 3274 3275
		return;
	}

3276
	isec = backing_inode_security(dentry);
3277
	spin_lock(&isec->lock);
3278
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
3279
	isec->sid = newsid;
3280
	isec->initialized = LABEL_INITIALIZED;
3281
	spin_unlock(&isec->lock);
3282

L
Linus Torvalds 已提交
3283 3284 3285
	return;
}

3286
static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
3287
{
3288 3289
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
3290
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
3291 3292
}

3293
static int selinux_inode_listxattr(struct dentry *dentry)
L
Linus Torvalds 已提交
3294
{
3295 3296
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
3297
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
3298 3299
}

3300
static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
3301
{
3302 3303
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
3304 3305 3306 3307 3308 3309

	/* No one is allowed to remove a SELinux security label.
	   You can change the label, but all data must be labeled. */
	return -EACCES;
}

3310
/*
3311
 * Copy the inode security context value to the user.
3312 3313 3314
 *
 * Permission check is handled by selinux_inode_getxattr hook.
 */
3315
static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc)
L
Linus Torvalds 已提交
3316
{
3317 3318 3319
	u32 size;
	int error;
	char *context = NULL;
3320
	struct inode_security_struct *isec;
3321

3322 3323
	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;
3324

3325 3326 3327 3328 3329 3330 3331 3332 3333
	/*
	 * If the caller has CAP_MAC_ADMIN, then get the raw context
	 * value even if it is not defined by current policy; otherwise,
	 * use the in-core value under current policy.
	 * Use the non-auditing forms of the permission checks since
	 * getxattr may be called by unprivileged processes commonly
	 * and lack of permission just means that we fall back to the
	 * in-core context value, not a denial.
	 */
3334
	isec = inode_security(inode);
3335
	if (has_cap_mac_admin(false))
3336 3337 3338 3339
		error = security_sid_to_context_force(isec->sid, &context,
						      &size);
	else
		error = security_sid_to_context(isec->sid, &context, &size);
3340 3341 3342 3343 3344 3345 3346 3347 3348 3349
	if (error)
		return error;
	error = size;
	if (alloc) {
		*buffer = context;
		goto out_nofree;
	}
	kfree(context);
out_nofree:
	return error;
L
Linus Torvalds 已提交
3350 3351 3352
}

static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3353
				     const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
3354
{
3355
	struct inode_security_struct *isec = inode_security_novalidate(inode);
L
Linus Torvalds 已提交
3356 3357 3358 3359 3360 3361 3362 3363 3364
	u32 newsid;
	int rc;

	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;

	if (!value || !size)
		return -EACCES;

3365
	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
L
Linus Torvalds 已提交
3366 3367 3368
	if (rc)
		return rc;

3369
	spin_lock(&isec->lock);
3370
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
3371
	isec->sid = newsid;
3372
	isec->initialized = LABEL_INITIALIZED;
3373
	spin_unlock(&isec->lock);
L
Linus Torvalds 已提交
3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384
	return 0;
}

static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
{
	const int len = sizeof(XATTR_NAME_SELINUX);
	if (buffer && len <= buffer_size)
		memcpy(buffer, XATTR_NAME_SELINUX, len);
	return len;
}

3385
static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3386
{
3387
	struct inode_security_struct *isec = inode_security_novalidate(inode);
3388 3389 3390
	*secid = isec->sid;
}

3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410
static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
{
	u32 sid;
	struct task_security_struct *tsec;
	struct cred *new_creds = *new;

	if (new_creds == NULL) {
		new_creds = prepare_creds();
		if (!new_creds)
			return -ENOMEM;
	}

	tsec = new_creds->security;
	/* Get label from overlay inode and set it in create_sid */
	selinux_inode_getsecid(d_inode(src), &sid);
	tsec->create_sid = sid;
	*new = new_creds;
	return 0;
}

3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425
static int selinux_inode_copy_up_xattr(const char *name)
{
	/* The copy_up hook above sets the initial context on an inode, but we
	 * don't then want to overwrite it by blindly copying all the lower
	 * xattrs up.  Instead, we have to filter out SELinux-related xattrs.
	 */
	if (strcmp(name, XATTR_NAME_SELINUX) == 0)
		return 1; /* Discard */
	/*
	 * Any other attribute apart from SELINUX is not claimed, supported
	 * by selinux.
	 */
	return -EOPNOTSUPP;
}

L
Linus Torvalds 已提交
3426 3427
/* file security operations */

3428
static int selinux_revalidate_file_permission(struct file *file, int mask)
L
Linus Torvalds 已提交
3429
{
3430
	const struct cred *cred = current_cred();
A
Al Viro 已提交
3431
	struct inode *inode = file_inode(file);
L
Linus Torvalds 已提交
3432 3433 3434 3435 3436

	/* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
	if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
		mask |= MAY_APPEND;

3437 3438
	return file_has_perm(cred, file,
			     file_mask_to_av(inode->i_mode, mask));
L
Linus Torvalds 已提交
3439 3440
}

3441 3442
static int selinux_file_permission(struct file *file, int mask)
{
A
Al Viro 已提交
3443
	struct inode *inode = file_inode(file);
3444
	struct file_security_struct *fsec = file->f_security;
3445
	struct inode_security_struct *isec;
3446 3447
	u32 sid = current_sid();

3448
	if (!mask)
3449 3450 3451
		/* No permission to check.  Existence test. */
		return 0;

3452
	isec = inode_security(inode);
3453 3454
	if (sid == fsec->sid && fsec->isid == isec->sid &&
	    fsec->pseqno == avc_policy_seqno())
3455
		/* No change since file_open check. */
3456 3457
		return 0;

3458 3459 3460
	return selinux_revalidate_file_permission(file, mask);
}

L
Linus Torvalds 已提交
3461 3462 3463 3464 3465 3466 3467 3468 3469 3470
static int selinux_file_alloc_security(struct file *file)
{
	return file_alloc_security(file);
}

static void selinux_file_free_security(struct file *file)
{
	file_free_security(file);
}

3471 3472 3473 3474
/*
 * Check whether a task has the ioctl permission and cmd
 * operation to an inode.
 */
3475
static int ioctl_has_perm(const struct cred *cred, struct file *file,
3476 3477 3478 3479 3480
		u32 requested, u16 cmd)
{
	struct common_audit_data ad;
	struct file_security_struct *fsec = file->f_security;
	struct inode *inode = file_inode(file);
3481
	struct inode_security_struct *isec;
3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504
	struct lsm_ioctlop_audit ioctl;
	u32 ssid = cred_sid(cred);
	int rc;
	u8 driver = cmd >> 8;
	u8 xperm = cmd & 0xff;

	ad.type = LSM_AUDIT_DATA_IOCTL_OP;
	ad.u.op = &ioctl;
	ad.u.op->cmd = cmd;
	ad.u.op->path = file->f_path;

	if (ssid != fsec->sid) {
		rc = avc_has_perm(ssid, fsec->sid,
				SECCLASS_FD,
				FD__USE,
				&ad);
		if (rc)
			goto out;
	}

	if (unlikely(IS_PRIVATE(inode)))
		return 0;

3505
	isec = inode_security(inode);
3506 3507 3508 3509 3510 3511
	rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
			requested, driver, xperm, &ad);
out:
	return rc;
}

L
Linus Torvalds 已提交
3512 3513 3514
static int selinux_file_ioctl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3515
	const struct cred *cred = current_cred();
3516
	int error = 0;
L
Linus Torvalds 已提交
3517

3518 3519 3520 3521 3522 3523 3524
	switch (cmd) {
	case FIONREAD:
	/* fall through */
	case FIBMAP:
	/* fall through */
	case FIGETBSZ:
	/* fall through */
3525
	case FS_IOC_GETFLAGS:
3526
	/* fall through */
3527
	case FS_IOC_GETVERSION:
3528 3529
		error = file_has_perm(cred, file, FILE__GETATTR);
		break;
L
Linus Torvalds 已提交
3530

3531
	case FS_IOC_SETFLAGS:
3532
	/* fall through */
3533
	case FS_IOC_SETVERSION:
3534 3535 3536 3537 3538 3539 3540 3541 3542
		error = file_has_perm(cred, file, FILE__SETATTR);
		break;

	/* sys_ioctl() checks */
	case FIONBIO:
	/* fall through */
	case FIOASYNC:
		error = file_has_perm(cred, file, 0);
		break;
L
Linus Torvalds 已提交
3543

3544 3545
	case KDSKBENT:
	case KDSKBSENT:
3546
		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3547
					    SECURITY_CAP_AUDIT, true);
3548 3549 3550 3551 3552 3553
		break;

	/* default case assumes that the command will go
	 * to the file's ioctl() function.
	 */
	default:
3554
		error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3555 3556
	}
	return error;
L
Linus Torvalds 已提交
3557 3558
}

3559 3560
static int default_noexec;

L
Linus Torvalds 已提交
3561 3562
static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
3563
	const struct cred *cred = current_cred();
3564
	u32 sid = cred_sid(cred);
D
David Howells 已提交
3565
	int rc = 0;
3566

3567
	if (default_noexec &&
3568 3569
	    (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
				   (!shared && (prot & PROT_WRITE)))) {
L
Linus Torvalds 已提交
3570 3571 3572 3573 3574
		/*
		 * We are making executable an anonymous mapping or a
		 * private file mapping that will also be writable.
		 * This has an additional check.
		 */
3575 3576
		rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
				  PROCESS__EXECMEM, NULL);
L
Linus Torvalds 已提交
3577
		if (rc)
D
David Howells 已提交
3578
			goto error;
L
Linus Torvalds 已提交
3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591
	}

	if (file) {
		/* read access is always possible with a mapping */
		u32 av = FILE__READ;

		/* write access only matters if the mapping is shared */
		if (shared && (prot & PROT_WRITE))
			av |= FILE__WRITE;

		if (prot & PROT_EXEC)
			av |= FILE__EXECUTE;

3592
		return file_has_perm(cred, file, av);
L
Linus Torvalds 已提交
3593
	}
D
David Howells 已提交
3594 3595 3596

error:
	return rc;
L
Linus Torvalds 已提交
3597 3598
}

3599
static int selinux_mmap_addr(unsigned long addr)
L
Linus Torvalds 已提交
3600
{
C
Casey Schaufler 已提交
3601
	int rc = 0;
L
Linus Torvalds 已提交
3602

3603
	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3604
		u32 sid = current_sid();
3605 3606
		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
				  MEMPROTECT__MMAP_ZERO, NULL);
3607 3608
	}

3609
	return rc;
3610
}
L
Linus Torvalds 已提交
3611

3612 3613 3614
static int selinux_mmap_file(struct file *file, unsigned long reqprot,
			     unsigned long prot, unsigned long flags)
{
3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626
	struct common_audit_data ad;
	int rc;

	if (file) {
		ad.type = LSM_AUDIT_DATA_FILE;
		ad.u.file = file;
		rc = inode_has_perm(current_cred(), file_inode(file),
				    FILE__MAP, &ad);
		if (rc)
			return rc;
	}

L
Linus Torvalds 已提交
3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637
	if (selinux_checkreqprot)
		prot = reqprot;

	return file_map_prot_check(file, prot,
				   (flags & MAP_TYPE) == MAP_SHARED);
}

static int selinux_file_mprotect(struct vm_area_struct *vma,
				 unsigned long reqprot,
				 unsigned long prot)
{
3638
	const struct cred *cred = current_cred();
3639
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
3640 3641 3642 3643

	if (selinux_checkreqprot)
		prot = reqprot;

3644 3645
	if (default_noexec &&
	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3646
		int rc = 0;
3647 3648
		if (vma->vm_start >= vma->vm_mm->start_brk &&
		    vma->vm_end <= vma->vm_mm->brk) {
3649 3650
			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
					  PROCESS__EXECHEAP, NULL);
3651
		} else if (!vma->vm_file &&
3652 3653
			   ((vma->vm_start <= vma->vm_mm->start_stack &&
			     vma->vm_end >= vma->vm_mm->start_stack) ||
3654
			    vma_is_stack_for_current(vma))) {
3655 3656
			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
					  PROCESS__EXECSTACK, NULL);
3657 3658 3659 3660 3661 3662 3663 3664
		} else if (vma->vm_file && vma->anon_vma) {
			/*
			 * We are making executable a file mapping that has
			 * had some COW done. Since pages might have been
			 * written, check ability to execute the possibly
			 * modified content.  This typically should only
			 * occur for text relocations.
			 */
D
David Howells 已提交
3665
			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3666
		}
3667 3668 3669
		if (rc)
			return rc;
	}
L
Linus Torvalds 已提交
3670 3671 3672 3673 3674 3675

	return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
}

static int selinux_file_lock(struct file *file, unsigned int cmd)
{
3676 3677 3678
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, FILE__LOCK);
L
Linus Torvalds 已提交
3679 3680 3681 3682 3683
}

static int selinux_file_fcntl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3684
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3685 3686 3687
	int err = 0;

	switch (cmd) {
3688 3689
	case F_SETFL:
		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3690
			err = file_has_perm(cred, file, FILE__WRITE);
L
Linus Torvalds 已提交
3691
			break;
3692 3693 3694 3695 3696 3697 3698
		}
		/* fall through */
	case F_SETOWN:
	case F_SETSIG:
	case F_GETFL:
	case F_GETOWN:
	case F_GETSIG:
3699
	case F_GETOWNER_UIDS:
3700
		/* Just check FD__USE permission */
3701
		err = file_has_perm(cred, file, 0);
3702 3703 3704 3705
		break;
	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
3706 3707 3708
	case F_OFD_GETLK:
	case F_OFD_SETLK:
	case F_OFD_SETLKW:
L
Linus Torvalds 已提交
3709
#if BITS_PER_LONG == 32
3710 3711 3712
	case F_GETLK64:
	case F_SETLK64:
	case F_SETLKW64:
L
Linus Torvalds 已提交
3713
#endif
3714
		err = file_has_perm(cred, file, FILE__LOCK);
3715
		break;
L
Linus Torvalds 已提交
3716 3717 3718 3719 3720
	}

	return err;
}

3721
static void selinux_file_set_fowner(struct file *file)
L
Linus Torvalds 已提交
3722 3723 3724 3725
{
	struct file_security_struct *fsec;

	fsec = file->f_security;
3726
	fsec->fown_sid = current_sid();
L
Linus Torvalds 已提交
3727 3728 3729 3730 3731
}

static int selinux_file_send_sigiotask(struct task_struct *tsk,
				       struct fown_struct *fown, int signum)
{
3732
	struct file *file;
3733
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
3734 3735 3736 3737
	u32 perm;
	struct file_security_struct *fsec;

	/* struct fown_struct is never outside the context of a struct file */
3738
	file = container_of(fown, struct file, f_owner);
L
Linus Torvalds 已提交
3739 3740 3741 3742 3743 3744 3745 3746

	fsec = file->f_security;

	if (!signum)
		perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
	else
		perm = signal_to_av(signum);

3747
	return avc_has_perm(fsec->fown_sid, sid,
L
Linus Torvalds 已提交
3748 3749 3750 3751 3752
			    SECCLASS_PROCESS, perm, NULL);
}

static int selinux_file_receive(struct file *file)
{
3753 3754 3755
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, file_to_av(file));
L
Linus Torvalds 已提交
3756 3757
}

3758
static int selinux_file_open(struct file *file, const struct cred *cred)
3759 3760 3761
{
	struct file_security_struct *fsec;
	struct inode_security_struct *isec;
D
David Howells 已提交
3762

3763
	fsec = file->f_security;
3764
	isec = inode_security(file_inode(file));
3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781
	/*
	 * Save inode label and policy sequence number
	 * at open-time so that selinux_file_permission
	 * can determine whether revalidation is necessary.
	 * Task label is already saved in the file security
	 * struct as its SID.
	 */
	fsec->isid = isec->sid;
	fsec->pseqno = avc_policy_seqno();
	/*
	 * Since the inode label or policy seqno may have changed
	 * between the selinux_inode_permission check and the saving
	 * of state above, recheck that access is still permitted.
	 * Otherwise, access might never be revalidated against the
	 * new inode label or new policy.
	 * This check is not redundant - do not remove.
	 */
3782
	return file_path_has_perm(cred, file, open_file_to_av(file));
3783 3784
}

L
Linus Torvalds 已提交
3785 3786
/* task security operations */

3787 3788
static int selinux_task_alloc(struct task_struct *task,
			      unsigned long clone_flags)
L
Linus Torvalds 已提交
3789
{
3790 3791 3792
	u32 sid = current_sid();

	return avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
L
Linus Torvalds 已提交
3793 3794
}

3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809
/*
 * allocate the SELinux part of blank credentials
 */
static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
	struct task_security_struct *tsec;

	tsec = kzalloc(sizeof(struct task_security_struct), gfp);
	if (!tsec)
		return -ENOMEM;

	cred->security = tsec;
	return 0;
}

D
David Howells 已提交
3810 3811 3812 3813
/*
 * detach and free the LSM part of a set of credentials
 */
static void selinux_cred_free(struct cred *cred)
L
Linus Torvalds 已提交
3814
{
D
David Howells 已提交
3815
	struct task_security_struct *tsec = cred->security;
3816

3817 3818 3819 3820 3821
	/*
	 * cred->security == NULL if security_cred_alloc_blank() or
	 * security_prepare_creds() returned an error.
	 */
	BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3822
	cred->security = (void *) 0x7UL;
D
David Howells 已提交
3823 3824
	kfree(tsec);
}
L
Linus Torvalds 已提交
3825

D
David Howells 已提交
3826 3827 3828 3829 3830 3831 3832 3833
/*
 * prepare a new set of credentials for modification
 */
static int selinux_cred_prepare(struct cred *new, const struct cred *old,
				gfp_t gfp)
{
	const struct task_security_struct *old_tsec;
	struct task_security_struct *tsec;
L
Linus Torvalds 已提交
3834

D
David Howells 已提交
3835
	old_tsec = old->security;
L
Linus Torvalds 已提交
3836

D
David Howells 已提交
3837 3838 3839
	tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
	if (!tsec)
		return -ENOMEM;
L
Linus Torvalds 已提交
3840

D
David Howells 已提交
3841
	new->security = tsec;
L
Linus Torvalds 已提交
3842 3843 3844
	return 0;
}

3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855
/*
 * transfer the SELinux data to a blank set of creds
 */
static void selinux_cred_transfer(struct cred *new, const struct cred *old)
{
	const struct task_security_struct *old_tsec = old->security;
	struct task_security_struct *tsec = new->security;

	*tsec = *old_tsec;
}

3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884
/*
 * set the security data for a kernel service
 * - all the creation contexts are set to unlabelled
 */
static int selinux_kernel_act_as(struct cred *new, u32 secid)
{
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

	ret = avc_has_perm(sid, secid,
			   SECCLASS_KERNEL_SERVICE,
			   KERNEL_SERVICE__USE_AS_OVERRIDE,
			   NULL);
	if (ret == 0) {
		tsec->sid = secid;
		tsec->create_sid = 0;
		tsec->keycreate_sid = 0;
		tsec->sockcreate_sid = 0;
	}
	return ret;
}

/*
 * set the file creation context in a security record to the same as the
 * objective context of the specified inode
 */
static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
{
3885
	struct inode_security_struct *isec = inode_security(inode);
3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

	ret = avc_has_perm(sid, isec->sid,
			   SECCLASS_KERNEL_SERVICE,
			   KERNEL_SERVICE__CREATE_FILES_AS,
			   NULL);

	if (ret == 0)
		tsec->create_sid = isec->sid;
3897
	return ret;
3898 3899
}

3900
static int selinux_kernel_module_request(char *kmod_name)
3901
{
3902 3903
	struct common_audit_data ad;

3904
	ad.type = LSM_AUDIT_DATA_KMOD;
3905 3906
	ad.u.kmod_name = kmod_name;

3907
	return avc_has_perm(current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
3908
			    SYSTEM__MODULE_REQUEST, &ad);
3909 3910
}

3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924
static int selinux_kernel_module_from_file(struct file *file)
{
	struct common_audit_data ad;
	struct inode_security_struct *isec;
	struct file_security_struct *fsec;
	u32 sid = current_sid();
	int rc;

	/* init_module */
	if (file == NULL)
		return avc_has_perm(sid, sid, SECCLASS_SYSTEM,
					SYSTEM__MODULE_LOAD, NULL);

	/* finit_module */
3925

3926 3927
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
3928 3929 3930 3931 3932 3933 3934 3935

	fsec = file->f_security;
	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, FD__USE, &ad);
		if (rc)
			return rc;
	}

3936
	isec = inode_security(file_inode(file));
3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956
	return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM,
				SYSTEM__MODULE_LOAD, &ad);
}

static int selinux_kernel_read_file(struct file *file,
				    enum kernel_read_file_id id)
{
	int rc = 0;

	switch (id) {
	case READING_MODULE:
		rc = selinux_kernel_module_from_file(file);
		break;
	default:
		break;
	}

	return rc;
}

L
Linus Torvalds 已提交
3957 3958
static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
{
3959 3960
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETPGID, NULL);
L
Linus Torvalds 已提交
3961 3962 3963 3964
}

static int selinux_task_getpgid(struct task_struct *p)
{
3965 3966
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__GETPGID, NULL);
L
Linus Torvalds 已提交
3967 3968 3969 3970
}

static int selinux_task_getsid(struct task_struct *p)
{
3971 3972
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__GETSESSION, NULL);
L
Linus Torvalds 已提交
3973 3974
}

3975 3976
static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
{
3977
	*secid = task_sid(p);
3978 3979
}

L
Linus Torvalds 已提交
3980 3981
static int selinux_task_setnice(struct task_struct *p, int nice)
{
3982 3983
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETSCHED, NULL);
L
Linus Torvalds 已提交
3984 3985
}

3986 3987
static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
3988 3989
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETSCHED, NULL);
3990 3991
}

3992 3993
static int selinux_task_getioprio(struct task_struct *p)
{
3994 3995
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__GETSCHED, NULL);
3996 3997
}

3998 3999 4000 4001 4002
int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred,
			 unsigned int flags)
{
	u32 av = 0;

4003 4004
	if (!flags)
		return 0;
4005 4006 4007 4008 4009 4010 4011 4012
	if (flags & LSM_PRLIMIT_WRITE)
		av |= PROCESS__SETRLIMIT;
	if (flags & LSM_PRLIMIT_READ)
		av |= PROCESS__GETRLIMIT;
	return avc_has_perm(cred_sid(cred), cred_sid(tcred),
			    SECCLASS_PROCESS, av, NULL);
}

4013 4014
static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
		struct rlimit *new_rlim)
L
Linus Torvalds 已提交
4015
{
4016
	struct rlimit *old_rlim = p->signal->rlim + resource;
L
Linus Torvalds 已提交
4017 4018 4019 4020

	/* Control the ability to change the hard limit (whether
	   lowering or raising it), so that the hard limit can
	   later be used as a safe reset point for the soft limit
D
David Howells 已提交
4021
	   upon context transitions.  See selinux_bprm_committing_creds. */
L
Linus Torvalds 已提交
4022
	if (old_rlim->rlim_max != new_rlim->rlim_max)
4023 4024
		return avc_has_perm(current_sid(), task_sid(p),
				    SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
L
Linus Torvalds 已提交
4025 4026 4027 4028

	return 0;
}

4029
static int selinux_task_setscheduler(struct task_struct *p)
L
Linus Torvalds 已提交
4030
{
4031 4032
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETSCHED, NULL);
L
Linus Torvalds 已提交
4033 4034 4035 4036
}

static int selinux_task_getscheduler(struct task_struct *p)
{
4037 4038
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__GETSCHED, NULL);
L
Linus Torvalds 已提交
4039 4040
}

4041 4042
static int selinux_task_movememory(struct task_struct *p)
{
4043 4044
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETSCHED, NULL);
4045 4046
}

4047 4048
static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
				int sig, u32 secid)
L
Linus Torvalds 已提交
4049 4050 4051 4052 4053 4054 4055
{
	u32 perm;

	if (!sig)
		perm = PROCESS__SIGNULL; /* null signal; existence test */
	else
		perm = signal_to_av(sig);
4056 4057 4058
	if (!secid)
		secid = current_sid();
	return avc_has_perm(secid, task_sid(p), SECCLASS_PROCESS, perm, NULL);
L
Linus Torvalds 已提交
4059 4060 4061 4062 4063 4064
}

static void selinux_task_to_inode(struct task_struct *p,
				  struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
4065
	u32 sid = task_sid(p);
L
Linus Torvalds 已提交
4066

4067
	spin_lock(&isec->lock);
4068
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
4069
	isec->sid = sid;
4070
	isec->initialized = LABEL_INITIALIZED;
4071
	spin_unlock(&isec->lock);
L
Linus Torvalds 已提交
4072 4073 4074
}

/* Returns error only if unable to parse addresses */
4075
static int selinux_parse_skb_ipv4(struct sk_buff *skb,
4076
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
4077 4078 4079 4080
{
	int offset, ihlen, ret = -EINVAL;
	struct iphdr _iph, *ih;

4081
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
4082 4083 4084 4085 4086 4087 4088 4089
	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
	if (ih == NULL)
		goto out;

	ihlen = ih->ihl * 4;
	if (ihlen < sizeof(_iph))
		goto out;

4090 4091
	ad->u.net->v4info.saddr = ih->saddr;
	ad->u.net->v4info.daddr = ih->daddr;
L
Linus Torvalds 已提交
4092 4093
	ret = 0;

4094 4095 4096
	if (proto)
		*proto = ih->protocol;

L
Linus Torvalds 已提交
4097
	switch (ih->protocol) {
4098 4099
	case IPPROTO_TCP: {
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
4100

4101 4102
		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;
L
Linus Torvalds 已提交
4103 4104 4105 4106 4107 4108

		offset += ihlen;
		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
		if (th == NULL)
			break;

4109 4110
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
4111
		break;
4112 4113 4114 4115 4116 4117 4118 4119
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

L
Linus Torvalds 已提交
4120
		offset += ihlen;
4121
		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
L
Linus Torvalds 已提交
4122
		if (uh == NULL)
4123
			break;
L
Linus Torvalds 已提交
4124

4125 4126
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
4127 4128
		break;
	}
L
Linus Torvalds 已提交
4129

J
James Morris 已提交
4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

		offset += ihlen;
		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
		if (dh == NULL)
			break;

4141 4142
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
4143
		break;
4144
	}
J
James Morris 已提交
4145

4146 4147 4148
	default:
		break;
	}
L
Linus Torvalds 已提交
4149 4150 4151 4152
out:
	return ret;
}

4153
#if IS_ENABLED(CONFIG_IPV6)
L
Linus Torvalds 已提交
4154 4155

/* Returns error only if unable to parse addresses */
4156
static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4157
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
4158 4159 4160 4161
{
	u8 nexthdr;
	int ret = -EINVAL, offset;
	struct ipv6hdr _ipv6h, *ip6;
4162
	__be16 frag_off;
L
Linus Torvalds 已提交
4163

4164
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
4165 4166 4167 4168
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		goto out;

4169 4170
	ad->u.net->v6info.saddr = ip6->saddr;
	ad->u.net->v6info.daddr = ip6->daddr;
L
Linus Torvalds 已提交
4171 4172 4173 4174
	ret = 0;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
4175
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
L
Linus Torvalds 已提交
4176 4177 4178
	if (offset < 0)
		goto out;

4179 4180 4181
	if (proto)
		*proto = nexthdr;

L
Linus Torvalds 已提交
4182 4183
	switch (nexthdr) {
	case IPPROTO_TCP: {
4184
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
4185 4186 4187 4188 4189

		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
		if (th == NULL)
			break;

4190 4191
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
4192 4193 4194 4195 4196 4197 4198 4199 4200 4201
		break;
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
		if (uh == NULL)
			break;

4202 4203
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
L
Linus Torvalds 已提交
4204 4205 4206
		break;
	}

J
James Morris 已提交
4207 4208 4209 4210 4211 4212 4213
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
		if (dh == NULL)
			break;

4214 4215
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
4216
		break;
4217
	}
J
James Morris 已提交
4218

L
Linus Torvalds 已提交
4219 4220 4221 4222 4223 4224 4225 4226 4227 4228
	/* includes fragments */
	default:
		break;
	}
out:
	return ret;
}

#endif /* IPV6 */

4229
static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4230
			     char **_addrp, int src, u8 *proto)
L
Linus Torvalds 已提交
4231
{
4232 4233
	char *addrp;
	int ret;
L
Linus Torvalds 已提交
4234

4235
	switch (ad->u.net->family) {
L
Linus Torvalds 已提交
4236
	case PF_INET:
4237
		ret = selinux_parse_skb_ipv4(skb, ad, proto);
4238 4239
		if (ret)
			goto parse_error;
4240 4241
		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
				       &ad->u.net->v4info.daddr);
4242
		goto okay;
L
Linus Torvalds 已提交
4243

4244
#if IS_ENABLED(CONFIG_IPV6)
L
Linus Torvalds 已提交
4245
	case PF_INET6:
4246
		ret = selinux_parse_skb_ipv6(skb, ad, proto);
4247 4248
		if (ret)
			goto parse_error;
4249 4250
		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
				       &ad->u.net->v6info.daddr);
4251
		goto okay;
L
Linus Torvalds 已提交
4252 4253
#endif	/* IPV6 */
	default:
4254 4255
		addrp = NULL;
		goto okay;
L
Linus Torvalds 已提交
4256 4257
	}

4258 4259 4260 4261
parse_error:
	printk(KERN_WARNING
	       "SELinux: failure in selinux_parse_skb(),"
	       " unable to parse packet\n");
L
Linus Torvalds 已提交
4262
	return ret;
4263 4264 4265 4266 4267

okay:
	if (_addrp)
		*_addrp = addrp;
	return 0;
L
Linus Torvalds 已提交
4268 4269
}

4270
/**
4271
 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4272
 * @skb: the packet
4273
 * @family: protocol family
4274
 * @sid: the packet's peer label SID
4275 4276
 *
 * Description:
4277 4278 4279 4280 4281 4282
 * Check the various different forms of network peer labeling and determine
 * the peer label/SID for the packet; most of the magic actually occurs in
 * the security server function security_net_peersid_cmp().  The function
 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
 * or -EACCES if @sid is invalid due to inconsistencies with the different
 * peer labels.
4283 4284
 *
 */
4285
static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4286
{
4287
	int err;
4288 4289
	u32 xfrm_sid;
	u32 nlbl_sid;
4290
	u32 nlbl_type;
4291

4292
	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4293 4294 4295 4296 4297
	if (unlikely(err))
		return -EACCES;
	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
	if (unlikely(err))
		return -EACCES;
4298

4299 4300 4301 4302 4303
	err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
	if (unlikely(err)) {
		printk(KERN_WARNING
		       "SELinux: failure in selinux_skb_peerlbl_sid(),"
		       " unable to determine packet's peer label\n");
4304
		return -EACCES;
4305
	}
4306 4307

	return 0;
4308 4309
}

4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333
/**
 * selinux_conn_sid - Determine the child socket label for a connection
 * @sk_sid: the parent socket's SID
 * @skb_sid: the packet's SID
 * @conn_sid: the resulting connection SID
 *
 * If @skb_sid is valid then the user:role:type information from @sk_sid is
 * combined with the MLS information from @skb_sid in order to create
 * @conn_sid.  If @skb_sid is not valid then then @conn_sid is simply a copy
 * of @sk_sid.  Returns zero on success, negative values on failure.
 *
 */
static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
{
	int err = 0;

	if (skb_sid != SECSID_NULL)
		err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid);
	else
		*conn_sid = sk_sid;

	return err;
}

L
Linus Torvalds 已提交
4334
/* socket security operations */
4335

4336 4337
static int socket_sockcreate_sid(const struct task_security_struct *tsec,
				 u16 secclass, u32 *socksid)
4338
{
4339 4340 4341 4342 4343 4344 4345
	if (tsec->sockcreate_sid > SECSID_NULL) {
		*socksid = tsec->sockcreate_sid;
		return 0;
	}

	return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
				       socksid);
4346 4347
}

4348
static int sock_has_perm(struct sock *sk, u32 perms)
L
Linus Torvalds 已提交
4349
{
4350
	struct sk_security_struct *sksec = sk->sk_security;
4351
	struct common_audit_data ad;
4352
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4353

4354 4355
	if (sksec->sid == SECINITSID_KERNEL)
		return 0;
L
Linus Torvalds 已提交
4356

4357
	ad.type = LSM_AUDIT_DATA_NET;
4358 4359
	ad.u.net = &net;
	ad.u.net->sk = sk;
L
Linus Torvalds 已提交
4360

4361 4362
	return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms,
			    &ad);
L
Linus Torvalds 已提交
4363 4364 4365 4366 4367
}

static int selinux_socket_create(int family, int type,
				 int protocol, int kern)
{
4368
	const struct task_security_struct *tsec = current_security();
4369
	u32 newsid;
4370
	u16 secclass;
4371
	int rc;
L
Linus Torvalds 已提交
4372 4373

	if (kern)
4374
		return 0;
4375 4376

	secclass = socket_type_to_security_class(family, type, protocol);
4377 4378 4379 4380
	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
	if (rc)
		return rc;

4381
	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
L
Linus Torvalds 已提交
4382 4383
}

V
Venkat Yekkirala 已提交
4384 4385
static int selinux_socket_post_create(struct socket *sock, int family,
				      int type, int protocol, int kern)
L
Linus Torvalds 已提交
4386
{
4387
	const struct task_security_struct *tsec = current_security();
4388
	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4389
	struct sk_security_struct *sksec;
4390 4391
	u16 sclass = socket_type_to_security_class(family, type, protocol);
	u32 sid = SECINITSID_KERNEL;
4392 4393
	int err = 0;

4394 4395
	if (!kern) {
		err = socket_sockcreate_sid(tsec, sclass, &sid);
4396 4397 4398
		if (err)
			return err;
	}
4399

4400 4401
	isec->sclass = sclass;
	isec->sid = sid;
4402
	isec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
4403

4404 4405
	if (sock->sk) {
		sksec = sock->sk->sk_security;
4406 4407
		sksec->sclass = sclass;
		sksec->sid = sid;
4408
		err = selinux_netlbl_socket_post_create(sock->sk, family);
4409 4410
	}

V
Venkat Yekkirala 已提交
4411
	return err;
L
Linus Torvalds 已提交
4412 4413 4414 4415 4416 4417 4418 4419
}

/* Range of port numbers used to automatically bind.
   Need to determine whether we should perform a name_bind
   permission check between the socket and the port number. */

static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
{
4420
	struct sock *sk = sock->sk;
L
Linus Torvalds 已提交
4421 4422 4423
	u16 family;
	int err;

4424
	err = sock_has_perm(sk, SOCKET__BIND);
L
Linus Torvalds 已提交
4425 4426 4427 4428 4429
	if (err)
		goto out;

	/*
	 * If PF_INET or PF_INET6, check name_bind permission for the port.
4430 4431
	 * Multiple address binding for SCTP is not supported yet: we just
	 * check the first address now.
L
Linus Torvalds 已提交
4432
	 */
4433
	family = sk->sk_family;
L
Linus Torvalds 已提交
4434 4435
	if (family == PF_INET || family == PF_INET6) {
		char *addrp;
4436
		struct sk_security_struct *sksec = sk->sk_security;
4437
		struct common_audit_data ad;
4438
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4439 4440 4441
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
4442
		u32 sid, node_perm;
L
Linus Torvalds 已提交
4443 4444

		if (family == PF_INET) {
4445 4446 4447 4448
			if (addrlen < sizeof(struct sockaddr_in)) {
				err = -EINVAL;
				goto out;
			}
L
Linus Torvalds 已提交
4449 4450 4451 4452
			addr4 = (struct sockaddr_in *)address;
			snum = ntohs(addr4->sin_port);
			addrp = (char *)&addr4->sin_addr.s_addr;
		} else {
4453 4454 4455 4456
			if (addrlen < SIN6_LEN_RFC2133) {
				err = -EINVAL;
				goto out;
			}
L
Linus Torvalds 已提交
4457 4458 4459 4460 4461
			addr6 = (struct sockaddr_in6 *)address;
			snum = ntohs(addr6->sin6_port);
			addrp = (char *)&addr6->sin6_addr.s6_addr;
		}

4462 4463 4464
		if (snum) {
			int low, high;

4465
			inet_get_local_port_range(sock_net(sk), &low, &high);
4466

4467 4468
			if (snum < max(inet_prot_sock(sock_net(sk)), low) ||
			    snum > high) {
P
Paul Moore 已提交
4469 4470
				err = sel_netport_sid(sk->sk_protocol,
						      snum, &sid);
4471 4472
				if (err)
					goto out;
4473
				ad.type = LSM_AUDIT_DATA_NET;
4474 4475 4476
				ad.u.net = &net;
				ad.u.net->sport = htons(snum);
				ad.u.net->family = family;
4477 4478
				err = avc_has_perm(sksec->sid, sid,
						   sksec->sclass,
4479 4480 4481 4482
						   SOCKET__NAME_BIND, &ad);
				if (err)
					goto out;
			}
L
Linus Torvalds 已提交
4483
		}
4484

4485
		switch (sksec->sclass) {
4486
		case SECCLASS_TCP_SOCKET:
L
Linus Torvalds 已提交
4487 4488
			node_perm = TCP_SOCKET__NODE_BIND;
			break;
4489

4490
		case SECCLASS_UDP_SOCKET:
L
Linus Torvalds 已提交
4491 4492
			node_perm = UDP_SOCKET__NODE_BIND;
			break;
J
James Morris 已提交
4493 4494 4495 4496 4497

		case SECCLASS_DCCP_SOCKET:
			node_perm = DCCP_SOCKET__NODE_BIND;
			break;

L
Linus Torvalds 已提交
4498 4499 4500 4501
		default:
			node_perm = RAWIP_SOCKET__NODE_BIND;
			break;
		}
4502

4503
		err = sel_netnode_sid(addrp, family, &sid);
L
Linus Torvalds 已提交
4504 4505
		if (err)
			goto out;
4506

4507
		ad.type = LSM_AUDIT_DATA_NET;
4508 4509 4510
		ad.u.net = &net;
		ad.u.net->sport = htons(snum);
		ad.u.net->family = family;
L
Linus Torvalds 已提交
4511 4512

		if (family == PF_INET)
4513
			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
L
Linus Torvalds 已提交
4514
		else
4515
			ad.u.net->v6info.saddr = addr6->sin6_addr;
L
Linus Torvalds 已提交
4516

4517 4518
		err = avc_has_perm(sksec->sid, sid,
				   sksec->sclass, node_perm, &ad);
L
Linus Torvalds 已提交
4519 4520 4521 4522 4523 4524 4525 4526 4527
		if (err)
			goto out;
	}
out:
	return err;
}

static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
{
4528
	struct sock *sk = sock->sk;
4529
	struct sk_security_struct *sksec = sk->sk_security;
L
Linus Torvalds 已提交
4530 4531
	int err;

4532
	err = sock_has_perm(sk, SOCKET__CONNECT);
L
Linus Torvalds 已提交
4533 4534 4535 4536
	if (err)
		return err;

	/*
J
James Morris 已提交
4537
	 * If a TCP or DCCP socket, check name_connect permission for the port.
L
Linus Torvalds 已提交
4538
	 */
4539 4540
	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
4541
		struct common_audit_data ad;
4542
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4543 4544 4545
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
J
James Morris 已提交
4546
		u32 sid, perm;
L
Linus Torvalds 已提交
4547 4548 4549

		if (sk->sk_family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
4550
			if (addrlen < sizeof(struct sockaddr_in))
L
Linus Torvalds 已提交
4551 4552 4553 4554
				return -EINVAL;
			snum = ntohs(addr4->sin_port);
		} else {
			addr6 = (struct sockaddr_in6 *)address;
4555
			if (addrlen < SIN6_LEN_RFC2133)
L
Linus Torvalds 已提交
4556 4557 4558 4559
				return -EINVAL;
			snum = ntohs(addr6->sin6_port);
		}

P
Paul Moore 已提交
4560
		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
L
Linus Torvalds 已提交
4561 4562 4563
		if (err)
			goto out;

4564
		perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
J
James Morris 已提交
4565 4566
		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;

4567
		ad.type = LSM_AUDIT_DATA_NET;
4568 4569 4570
		ad.u.net = &net;
		ad.u.net->dport = htons(snum);
		ad.u.net->family = sk->sk_family;
4571
		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
L
Linus Torvalds 已提交
4572 4573 4574 4575
		if (err)
			goto out;
	}

4576 4577
	err = selinux_netlbl_socket_connect(sk, address);

L
Linus Torvalds 已提交
4578 4579 4580 4581 4582 4583
out:
	return err;
}

static int selinux_socket_listen(struct socket *sock, int backlog)
{
4584
	return sock_has_perm(sock->sk, SOCKET__LISTEN);
L
Linus Torvalds 已提交
4585 4586 4587 4588 4589 4590 4591
}

static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
{
	int err;
	struct inode_security_struct *isec;
	struct inode_security_struct *newisec;
4592 4593
	u16 sclass;
	u32 sid;
L
Linus Torvalds 已提交
4594

4595
	err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
L
Linus Torvalds 已提交
4596 4597 4598
	if (err)
		return err;

4599
	isec = inode_security_novalidate(SOCK_INODE(sock));
4600 4601 4602 4603 4604 4605 4606 4607
	spin_lock(&isec->lock);
	sclass = isec->sclass;
	sid = isec->sid;
	spin_unlock(&isec->lock);

	newisec = inode_security_novalidate(SOCK_INODE(newsock));
	newisec->sclass = sclass;
	newisec->sid = sid;
4608
	newisec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
4609 4610 4611 4612 4613

	return 0;
}

static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4614
				  int size)
L
Linus Torvalds 已提交
4615
{
4616
	return sock_has_perm(sock->sk, SOCKET__WRITE);
L
Linus Torvalds 已提交
4617 4618 4619 4620 4621
}

static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
				  int size, int flags)
{
4622
	return sock_has_perm(sock->sk, SOCKET__READ);
L
Linus Torvalds 已提交
4623 4624 4625 4626
}

static int selinux_socket_getsockname(struct socket *sock)
{
4627
	return sock_has_perm(sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4628 4629 4630 4631
}

static int selinux_socket_getpeername(struct socket *sock)
{
4632
	return sock_has_perm(sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4633 4634
}

4635
static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
L
Linus Torvalds 已提交
4636
{
4637 4638
	int err;

4639
	err = sock_has_perm(sock->sk, SOCKET__SETOPT);
4640 4641 4642 4643
	if (err)
		return err;

	return selinux_netlbl_socket_setsockopt(sock, level, optname);
L
Linus Torvalds 已提交
4644 4645 4646 4647 4648
}

static int selinux_socket_getsockopt(struct socket *sock, int level,
				     int optname)
{
4649
	return sock_has_perm(sock->sk, SOCKET__GETOPT);
L
Linus Torvalds 已提交
4650 4651 4652 4653
}

static int selinux_socket_shutdown(struct socket *sock, int how)
{
4654
	return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
L
Linus Torvalds 已提交
4655 4656
}

4657 4658
static int selinux_socket_unix_stream_connect(struct sock *sock,
					      struct sock *other,
L
Linus Torvalds 已提交
4659 4660
					      struct sock *newsk)
{
4661 4662
	struct sk_security_struct *sksec_sock = sock->sk_security;
	struct sk_security_struct *sksec_other = other->sk_security;
4663
	struct sk_security_struct *sksec_new = newsk->sk_security;
4664
	struct common_audit_data ad;
4665
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4666 4667
	int err;

4668
	ad.type = LSM_AUDIT_DATA_NET;
4669 4670
	ad.u.net = &net;
	ad.u.net->sk = other;
L
Linus Torvalds 已提交
4671

4672 4673
	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
			   sksec_other->sclass,
L
Linus Torvalds 已提交
4674 4675 4676 4677 4678
			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
	if (err)
		return err;

	/* server child socket */
4679 4680 4681 4682 4683
	sksec_new->peer_sid = sksec_sock->sid;
	err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
				    &sksec_new->sid);
	if (err)
		return err;
4684

4685 4686 4687 4688
	/* connecting socket */
	sksec_sock->peer_sid = sksec_new->sid;

	return 0;
L
Linus Torvalds 已提交
4689 4690 4691 4692 4693
}

static int selinux_socket_unix_may_send(struct socket *sock,
					struct socket *other)
{
4694 4695
	struct sk_security_struct *ssec = sock->sk->sk_security;
	struct sk_security_struct *osec = other->sk->sk_security;
4696
	struct common_audit_data ad;
4697
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4698

4699
	ad.type = LSM_AUDIT_DATA_NET;
4700 4701
	ad.u.net = &net;
	ad.u.net->sk = other->sk;
L
Linus Torvalds 已提交
4702

4703 4704
	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
			    &ad);
L
Linus Torvalds 已提交
4705 4706
}

4707 4708
static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
				    char *addrp, u16 family, u32 peer_sid,
4709
				    struct common_audit_data *ad)
4710 4711 4712 4713 4714
{
	int err;
	u32 if_sid;
	u32 node_sid;

4715
	err = sel_netif_sid(ns, ifindex, &if_sid);
4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727 4728 4729
	if (err)
		return err;
	err = avc_has_perm(peer_sid, if_sid,
			   SECCLASS_NETIF, NETIF__INGRESS, ad);
	if (err)
		return err;

	err = sel_netnode_sid(addrp, family, &node_sid);
	if (err)
		return err;
	return avc_has_perm(peer_sid, node_sid,
			    SECCLASS_NODE, NODE__RECVFROM, ad);
}

4730
static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4731
				       u16 family)
4732
{
4733
	int err = 0;
4734 4735
	struct sk_security_struct *sksec = sk->sk_security;
	u32 sk_sid = sksec->sid;
4736
	struct common_audit_data ad;
4737
	struct lsm_network_audit net = {0,};
4738 4739
	char *addrp;

4740
	ad.type = LSM_AUDIT_DATA_NET;
4741 4742 4743
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4744 4745 4746
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
	if (err)
		return err;
L
Linus Torvalds 已提交
4747

4748
	if (selinux_secmark_enabled()) {
4749
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4750
				   PACKET__RECV, &ad);
4751 4752 4753
		if (err)
			return err;
	}
4754

4755 4756 4757 4758
	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
	if (err)
		return err;
	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4759

4760 4761 4762 4763 4764
	return err;
}

static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
4765
	int err;
4766
	struct sk_security_struct *sksec = sk->sk_security;
4767 4768
	u16 family = sk->sk_family;
	u32 sk_sid = sksec->sid;
4769
	struct common_audit_data ad;
4770
	struct lsm_network_audit net = {0,};
4771
	char *addrp;
4772 4773
	u8 secmark_active;
	u8 peerlbl_active;
4774 4775

	if (family != PF_INET && family != PF_INET6)
4776
		return 0;
4777 4778

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
A
Al Viro 已提交
4779
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4780 4781
		family = PF_INET;

4782 4783 4784 4785
	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_sock_rcv_skb_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
4786
	if (!selinux_policycap_netpeer)
4787 4788 4789
		return selinux_sock_rcv_skb_compat(sk, skb, family);

	secmark_active = selinux_secmark_enabled();
4790
	peerlbl_active = selinux_peerlbl_enabled();
4791 4792 4793
	if (!secmark_active && !peerlbl_active)
		return 0;

4794
	ad.type = LSM_AUDIT_DATA_NET;
4795 4796 4797
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4798
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4799
	if (err)
4800
		return err;
4801

4802
	if (peerlbl_active) {
4803 4804 4805
		u32 peer_sid;

		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4806 4807
		if (err)
			return err;
4808 4809
		err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
					       addrp, family, peer_sid, &ad);
4810
		if (err) {
4811
			selinux_netlbl_err(skb, family, err, 0);
4812
			return err;
4813
		}
4814 4815
		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
				   PEER__RECV, &ad);
C
Chad Hanson 已提交
4816
		if (err) {
4817
			selinux_netlbl_err(skb, family, err, 0);
C
Chad Hanson 已提交
4818 4819
			return err;
		}
4820 4821
	}

4822
	if (secmark_active) {
4823 4824 4825 4826 4827 4828
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
				   PACKET__RECV, &ad);
		if (err)
			return err;
	}

4829
	return err;
L
Linus Torvalds 已提交
4830 4831
}

C
Catherine Zhang 已提交
4832 4833
static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
					    int __user *optlen, unsigned len)
L
Linus Torvalds 已提交
4834 4835 4836 4837
{
	int err = 0;
	char *scontext;
	u32 scontext_len;
4838
	struct sk_security_struct *sksec = sock->sk->sk_security;
4839
	u32 peer_sid = SECSID_NULL;
L
Linus Torvalds 已提交
4840

4841 4842
	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
	    sksec->sclass == SECCLASS_TCP_SOCKET)
4843
		peer_sid = sksec->peer_sid;
4844 4845
	if (peer_sid == SECSID_NULL)
		return -ENOPROTOOPT;
L
Linus Torvalds 已提交
4846

C
Catherine Zhang 已提交
4847
	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
L
Linus Torvalds 已提交
4848
	if (err)
4849
		return err;
L
Linus Torvalds 已提交
4850 4851 4852 4853 4854 4855 4856 4857 4858 4859 4860 4861 4862 4863 4864 4865

	if (scontext_len > len) {
		err = -ERANGE;
		goto out_len;
	}

	if (copy_to_user(optval, scontext, scontext_len))
		err = -EFAULT;

out_len:
	if (put_user(scontext_len, optlen))
		err = -EFAULT;
	kfree(scontext);
	return err;
}

4866
static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
C
Catherine Zhang 已提交
4867
{
4868
	u32 peer_secid = SECSID_NULL;
4869
	u16 family;
4870
	struct inode_security_struct *isec;
C
Catherine Zhang 已提交
4871

4872 4873 4874 4875 4876
	if (skb && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;
	else if (skb && skb->protocol == htons(ETH_P_IPV6))
		family = PF_INET6;
	else if (sock)
4877 4878 4879 4880
		family = sock->sk->sk_family;
	else
		goto out;

4881 4882 4883 4884
	if (sock && family == PF_UNIX) {
		isec = inode_security_novalidate(SOCK_INODE(sock));
		peer_secid = isec->sid;
	} else if (skb)
4885
		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
C
Catherine Zhang 已提交
4886

4887
out:
4888
	*secid = peer_secid;
4889 4890 4891
	if (peer_secid == SECSID_NULL)
		return -EINVAL;
	return 0;
C
Catherine Zhang 已提交
4892 4893
}

A
Al Viro 已提交
4894
static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
L
Linus Torvalds 已提交
4895
{
4896 4897 4898 4899 4900 4901 4902 4903
	struct sk_security_struct *sksec;

	sksec = kzalloc(sizeof(*sksec), priority);
	if (!sksec)
		return -ENOMEM;

	sksec->peer_sid = SECINITSID_UNLABELED;
	sksec->sid = SECINITSID_UNLABELED;
4904
	sksec->sclass = SECCLASS_SOCKET;
4905 4906 4907 4908
	selinux_netlbl_sk_security_reset(sksec);
	sk->sk_security = sksec;

	return 0;
L
Linus Torvalds 已提交
4909 4910 4911 4912
}

static void selinux_sk_free_security(struct sock *sk)
{
4913 4914 4915 4916 4917
	struct sk_security_struct *sksec = sk->sk_security;

	sk->sk_security = NULL;
	selinux_netlbl_sk_security_free(sksec);
	kfree(sksec);
L
Linus Torvalds 已提交
4918 4919
}

4920
static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4921
{
4922 4923
	struct sk_security_struct *sksec = sk->sk_security;
	struct sk_security_struct *newsksec = newsk->sk_security;
4924

4925 4926 4927
	newsksec->sid = sksec->sid;
	newsksec->peer_sid = sksec->peer_sid;
	newsksec->sclass = sksec->sclass;
4928

4929
	selinux_netlbl_sk_security_reset(newsksec);
4930 4931
}

V
Venkat Yekkirala 已提交
4932
static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4933
{
4934
	if (!sk)
V
Venkat Yekkirala 已提交
4935
		*secid = SECINITSID_ANY_SOCKET;
4936 4937
	else {
		struct sk_security_struct *sksec = sk->sk_security;
4938

V
Venkat Yekkirala 已提交
4939
		*secid = sksec->sid;
4940
	}
4941 4942
}

4943
static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4944
{
4945 4946
	struct inode_security_struct *isec =
		inode_security_novalidate(SOCK_INODE(parent));
4947 4948
	struct sk_security_struct *sksec = sk->sk_security;

4949 4950
	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
	    sk->sk_family == PF_UNIX)
4951
		isec->sid = sksec->sid;
4952
	sksec->sclass = isec->sclass;
4953 4954
}

4955 4956
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				     struct request_sock *req)
4957 4958 4959
{
	struct sk_security_struct *sksec = sk->sk_security;
	int err;
4960
	u16 family = req->rsk_ops->family;
4961
	u32 connsid;
4962 4963
	u32 peersid;

4964
	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4965 4966
	if (err)
		return err;
4967 4968 4969 4970 4971
	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
	if (err)
		return err;
	req->secid = connsid;
	req->peer_secid = peersid;
4972

4973
	return selinux_netlbl_inet_conn_request(req, family);
4974 4975
}

4976 4977
static void selinux_inet_csk_clone(struct sock *newsk,
				   const struct request_sock *req)
4978 4979 4980 4981
{
	struct sk_security_struct *newsksec = newsk->sk_security;

	newsksec->sid = req->secid;
4982
	newsksec->peer_sid = req->peer_secid;
4983 4984 4985 4986
	/* NOTE: Ideally, we should also get the isec->sid for the
	   new socket in sync, but we don't have the isec available yet.
	   So we will wait until sock_graft to do it, by which
	   time it will have been created and available. */
4987

P
Paul Moore 已提交
4988 4989
	/* We don't need to take any sort of lock here as we are the only
	 * thread with access to newsksec */
4990
	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4991 4992
}

4993
static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4994
{
4995
	u16 family = sk->sk_family;
4996 4997
	struct sk_security_struct *sksec = sk->sk_security;

4998 4999 5000 5001 5002
	/* handle mapped IPv4 packets arriving via IPv6 sockets */
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;

	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
5003 5004
}

5005 5006 5007 5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025
static int selinux_secmark_relabel_packet(u32 sid)
{
	const struct task_security_struct *__tsec;
	u32 tsid;

	__tsec = current_security();
	tsid = __tsec->sid;

	return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
}

static void selinux_secmark_refcount_inc(void)
{
	atomic_inc(&selinux_secmark_refcount);
}

static void selinux_secmark_refcount_dec(void)
{
	atomic_dec(&selinux_secmark_refcount);
}

5026 5027
static void selinux_req_classify_flow(const struct request_sock *req,
				      struct flowi *fl)
5028
{
5029
	fl->flowi_secid = req->secid;
5030 5031
}

5032 5033 5034 5035 5036 5037 5038 5039 5040 5041 5042 5043 5044 5045 5046 5047 5048 5049
static int selinux_tun_dev_alloc_security(void **security)
{
	struct tun_security_struct *tunsec;

	tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL);
	if (!tunsec)
		return -ENOMEM;
	tunsec->sid = current_sid();

	*security = tunsec;
	return 0;
}

static void selinux_tun_dev_free_security(void *security)
{
	kfree(security);
}

5050 5051 5052 5053 5054 5055 5056 5057 5058 5059 5060 5061 5062 5063 5064
static int selinux_tun_dev_create(void)
{
	u32 sid = current_sid();

	/* we aren't taking into account the "sockcreate" SID since the socket
	 * that is being created here is not a socket in the traditional sense,
	 * instead it is a private sock, accessible only to the kernel, and
	 * representing a wide range of network traffic spanning multiple
	 * connections unlike traditional sockets - check the TUN driver to
	 * get a better understanding of why this socket is special */

	return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
			    NULL);
}

5065
static int selinux_tun_dev_attach_queue(void *security)
5066
{
5067 5068 5069 5070 5071 5072 5073 5074 5075
	struct tun_security_struct *tunsec = security;

	return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET,
			    TUN_SOCKET__ATTACH_QUEUE, NULL);
}

static int selinux_tun_dev_attach(struct sock *sk, void *security)
{
	struct tun_security_struct *tunsec = security;
5076 5077 5078 5079 5080 5081 5082 5083 5084
	struct sk_security_struct *sksec = sk->sk_security;

	/* we don't currently perform any NetLabel based labeling here and it
	 * isn't clear that we would want to do so anyway; while we could apply
	 * labeling without the support of the TUN user the resulting labeled
	 * traffic from the other end of the connection would almost certainly
	 * cause confusion to the TUN user that had no idea network labeling
	 * protocols were being used */

5085
	sksec->sid = tunsec->sid;
5086
	sksec->sclass = SECCLASS_TUN_SOCKET;
5087 5088

	return 0;
5089 5090
}

5091
static int selinux_tun_dev_open(void *security)
5092
{
5093
	struct tun_security_struct *tunsec = security;
5094 5095 5096
	u32 sid = current_sid();
	int err;

5097
	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
5098 5099 5100 5101 5102 5103 5104
			   TUN_SOCKET__RELABELFROM, NULL);
	if (err)
		return err;
	err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
			   TUN_SOCKET__RELABELTO, NULL);
	if (err)
		return err;
5105
	tunsec->sid = sid;
5106 5107 5108 5109

	return 0;
}

L
Linus Torvalds 已提交
5110 5111 5112 5113 5114
static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
{
	int err = 0;
	u32 perm;
	struct nlmsghdr *nlh;
5115
	struct sk_security_struct *sksec = sk->sk_security;
5116

5117
	if (skb->len < NLMSG_HDRLEN) {
L
Linus Torvalds 已提交
5118 5119 5120
		err = -EINVAL;
		goto out;
	}
5121
	nlh = nlmsg_hdr(skb);
5122

5123
	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
L
Linus Torvalds 已提交
5124 5125
	if (err) {
		if (err == -EINVAL) {
5126 5127 5128
			pr_warn_ratelimited("SELinux: unrecognized netlink"
			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
			       " pig=%d comm=%s\n",
5129
			       sk->sk_protocol, nlh->nlmsg_type,
5130 5131
			       secclass_map[sksec->sclass - 1].name,
			       task_pid_nr(current), current->comm);
5132
			if (!selinux_enforcing || security_get_allow_unknown())
L
Linus Torvalds 已提交
5133 5134 5135 5136 5137 5138 5139 5140 5141
				err = 0;
		}

		/* Ignore */
		if (err == -ENOENT)
			err = 0;
		goto out;
	}

5142
	err = sock_has_perm(sk, perm);
L
Linus Torvalds 已提交
5143 5144 5145 5146 5147 5148
out:
	return err;
}

#ifdef CONFIG_NETFILTER

5149 5150
static unsigned int selinux_ip_forward(struct sk_buff *skb,
				       const struct net_device *indev,
5151
				       u16 family)
L
Linus Torvalds 已提交
5152
{
5153
	int err;
5154 5155
	char *addrp;
	u32 peer_sid;
5156
	struct common_audit_data ad;
5157
	struct lsm_network_audit net = {0,};
5158
	u8 secmark_active;
5159
	u8 netlbl_active;
5160
	u8 peerlbl_active;
5161

5162 5163
	if (!selinux_policycap_netpeer)
		return NF_ACCEPT;
5164

5165
	secmark_active = selinux_secmark_enabled();
5166
	netlbl_active = netlbl_enabled();
5167
	peerlbl_active = selinux_peerlbl_enabled();
5168 5169
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;
5170

5171 5172 5173
	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
		return NF_DROP;

5174
	ad.type = LSM_AUDIT_DATA_NET;
5175
	ad.u.net = &net;
5176
	ad.u.net->netif = indev->ifindex;
5177
	ad.u.net->family = family;
5178 5179 5180
	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
		return NF_DROP;

5181
	if (peerlbl_active) {
5182 5183
		err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
					       addrp, family, peer_sid, &ad);
5184
		if (err) {
5185
			selinux_netlbl_err(skb, family, err, 1);
5186
			return NF_DROP;
5187 5188
		}
	}
5189 5190 5191 5192 5193 5194

	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
			return NF_DROP;

5195 5196 5197 5198 5199 5200 5201 5202
	if (netlbl_active)
		/* we do this in the FORWARD path and not the POST_ROUTING
		 * path because we want to make sure we apply the necessary
		 * labeling before IPsec is applied so we can leverage AH
		 * protection */
		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
			return NF_DROP;

5203 5204 5205
	return NF_ACCEPT;
}

5206
static unsigned int selinux_ipv4_forward(void *priv,
5207
					 struct sk_buff *skb,
5208
					 const struct nf_hook_state *state)
5209
{
5210
	return selinux_ip_forward(skb, state->in, PF_INET);
5211 5212
}

5213
#if IS_ENABLED(CONFIG_IPV6)
5214
static unsigned int selinux_ipv6_forward(void *priv,
5215
					 struct sk_buff *skb,
5216
					 const struct nf_hook_state *state)
5217
{
5218
	return selinux_ip_forward(skb, state->in, PF_INET6);
5219 5220 5221
}
#endif	/* IPV6 */

5222 5223 5224
static unsigned int selinux_ip_output(struct sk_buff *skb,
				      u16 family)
{
5225
	struct sock *sk;
5226 5227 5228 5229 5230 5231 5232 5233
	u32 sid;

	if (!netlbl_enabled())
		return NF_ACCEPT;

	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
	 * because we want to make sure we apply the necessary labeling
	 * before IPsec is applied so we can leverage AH protection */
5234 5235 5236 5237
	sk = skb->sk;
	if (sk) {
		struct sk_security_struct *sksec;

5238
		if (sk_listener(sk))
5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254
			/* if the socket is the listening state then this
			 * packet is a SYN-ACK packet which means it needs to
			 * be labeled based on the connection/request_sock and
			 * not the parent socket.  unfortunately, we can't
			 * lookup the request_sock yet as it isn't queued on
			 * the parent socket until after the SYN-ACK is sent.
			 * the "solution" is to simply pass the packet as-is
			 * as any IP option based labeling should be copied
			 * from the initial connection request (in the IP
			 * layer).  it is far from ideal, but until we get a
			 * security label in the packet itself this is the
			 * best we can do. */
			return NF_ACCEPT;

		/* standard practice, label using the parent socket */
		sksec = sk->sk_security;
5255 5256 5257 5258 5259 5260 5261 5262 5263
		sid = sksec->sid;
	} else
		sid = SECINITSID_KERNEL;
	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
		return NF_DROP;

	return NF_ACCEPT;
}

5264
static unsigned int selinux_ipv4_output(void *priv,
5265
					struct sk_buff *skb,
5266
					const struct nf_hook_state *state)
5267 5268 5269 5270
{
	return selinux_ip_output(skb, PF_INET);
}

5271
#if IS_ENABLED(CONFIG_IPV6)
5272 5273 5274 5275 5276 5277 5278 5279
static unsigned int selinux_ipv6_output(void *priv,
					struct sk_buff *skb,
					const struct nf_hook_state *state)
{
	return selinux_ip_output(skb, PF_INET6);
}
#endif	/* IPV6 */

5280 5281
static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
						int ifindex,
5282
						u16 family)
5283
{
5284
	struct sock *sk = skb_to_full_sk(skb);
5285
	struct sk_security_struct *sksec;
5286
	struct common_audit_data ad;
5287
	struct lsm_network_audit net = {0,};
5288 5289
	char *addrp;
	u8 proto;
L
Linus Torvalds 已提交
5290

5291 5292 5293 5294
	if (sk == NULL)
		return NF_ACCEPT;
	sksec = sk->sk_security;

5295
	ad.type = LSM_AUDIT_DATA_NET;
5296 5297 5298
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
5299 5300 5301
	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
		return NF_DROP;

5302
	if (selinux_secmark_enabled())
5303
		if (avc_has_perm(sksec->sid, skb->secmark,
5304
				 SECCLASS_PACKET, PACKET__SEND, &ad))
5305
			return NF_DROP_ERR(-ECONNREFUSED);
5306

5307 5308
	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
		return NF_DROP_ERR(-ECONNREFUSED);
5309 5310

	return NF_ACCEPT;
5311 5312
}

5313 5314
static unsigned int selinux_ip_postroute(struct sk_buff *skb,
					 const struct net_device *outdev,
5315
					 u16 family)
5316
{
5317 5318
	u32 secmark_perm;
	u32 peer_sid;
5319
	int ifindex = outdev->ifindex;
5320
	struct sock *sk;
5321
	struct common_audit_data ad;
5322
	struct lsm_network_audit net = {0,};
5323 5324 5325
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;
5326

5327 5328 5329 5330
	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_ip_postroute_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
5331
	if (!selinux_policycap_netpeer)
5332
		return selinux_ip_postroute_compat(skb, ifindex, family);
5333 5334 5335 5336 5337 5338

	secmark_active = selinux_secmark_enabled();
	peerlbl_active = selinux_peerlbl_enabled();
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;

5339
	sk = skb_to_full_sk(skb);
5340

5341
#ifdef CONFIG_XFRM
5342 5343 5344 5345 5346
	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
	 * packet transformation so allow the packet to pass without any checks
	 * since we'll have another chance to perform access control checks
	 * when the packet is on it's final way out.
	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5347 5348 5349 5350 5351 5352 5353
	 *       is NULL, in this case go ahead and apply access control.
	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
	 *       TCP listening state we cannot wait until the XFRM processing
	 *       is done as we will miss out on the SA label if we do;
	 *       unfortunately, this means more work, but it is only once per
	 *       connection. */
	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5354
	    !(sk && sk_listener(sk)))
5355
		return NF_ACCEPT;
5356
#endif
5357

5358
	if (sk == NULL) {
5359 5360 5361 5362
		/* Without an associated socket the packet is either coming
		 * from the kernel or it is being forwarded; check the packet
		 * to determine which and if the packet is being forwarded
		 * query the packet directly to determine the security label. */
5363 5364
		if (skb->skb_iif) {
			secmark_perm = PACKET__FORWARD_OUT;
5365
			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5366
				return NF_DROP;
5367 5368
		} else {
			secmark_perm = PACKET__SEND;
5369
			peer_sid = SECINITSID_KERNEL;
5370
		}
5371
	} else if (sk_listener(sk)) {
5372 5373 5374 5375 5376 5377 5378 5379 5380 5381
		/* Locally generated packet but the associated socket is in the
		 * listening state which means this is a SYN-ACK packet.  In
		 * this particular case the correct security label is assigned
		 * to the connection/request_sock but unfortunately we can't
		 * query the request_sock as it isn't queued on the parent
		 * socket until after the SYN-ACK packet is sent; the only
		 * viable choice is to regenerate the label like we do in
		 * selinux_inet_conn_request().  See also selinux_ip_output()
		 * for similar problems. */
		u32 skb_sid;
5382 5383 5384
		struct sk_security_struct *sksec;

		sksec = sk->sk_security;
5385 5386
		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
			return NF_DROP;
5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401
		/* At this point, if the returned skb peerlbl is SECSID_NULL
		 * and the packet has been through at least one XFRM
		 * transformation then we must be dealing with the "final"
		 * form of labeled IPsec packet; since we've already applied
		 * all of our access controls on this packet we can safely
		 * pass the packet. */
		if (skb_sid == SECSID_NULL) {
			switch (family) {
			case PF_INET:
				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
					return NF_ACCEPT;
				break;
			case PF_INET6:
				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
					return NF_ACCEPT;
5402
				break;
5403 5404 5405 5406
			default:
				return NF_DROP_ERR(-ECONNREFUSED);
			}
		}
5407 5408 5409
		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
			return NF_DROP;
		secmark_perm = PACKET__SEND;
5410
	} else {
5411 5412
		/* Locally generated packet, fetch the security label from the
		 * associated socket. */
5413 5414 5415 5416
		struct sk_security_struct *sksec = sk->sk_security;
		peer_sid = sksec->sid;
		secmark_perm = PACKET__SEND;
	}
5417

5418
	ad.type = LSM_AUDIT_DATA_NET;
5419 5420 5421
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
5422
	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5423
		return NF_DROP;
5424

5425 5426 5427
	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, secmark_perm, &ad))
5428
			return NF_DROP_ERR(-ECONNREFUSED);
5429 5430 5431 5432 5433

	if (peerlbl_active) {
		u32 if_sid;
		u32 node_sid;

5434
		if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
5435
			return NF_DROP;
5436 5437
		if (avc_has_perm(peer_sid, if_sid,
				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5438
			return NF_DROP_ERR(-ECONNREFUSED);
5439 5440

		if (sel_netnode_sid(addrp, family, &node_sid))
5441
			return NF_DROP;
5442 5443
		if (avc_has_perm(peer_sid, node_sid,
				 SECCLASS_NODE, NODE__SENDTO, &ad))
5444
			return NF_DROP_ERR(-ECONNREFUSED);
5445
	}
5446

5447
	return NF_ACCEPT;
L
Linus Torvalds 已提交
5448 5449
}

5450
static unsigned int selinux_ipv4_postroute(void *priv,
5451
					   struct sk_buff *skb,
5452
					   const struct nf_hook_state *state)
L
Linus Torvalds 已提交
5453
{
5454
	return selinux_ip_postroute(skb, state->out, PF_INET);
L
Linus Torvalds 已提交
5455 5456
}

5457
#if IS_ENABLED(CONFIG_IPV6)
5458
static unsigned int selinux_ipv6_postroute(void *priv,
5459
					   struct sk_buff *skb,
5460
					   const struct nf_hook_state *state)
L
Linus Torvalds 已提交
5461
{
5462
	return selinux_ip_postroute(skb, state->out, PF_INET6);
L
Linus Torvalds 已提交
5463 5464 5465 5466 5467 5468 5469
}
#endif	/* IPV6 */

#endif	/* CONFIG_NETFILTER */

static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
{
5470
	return selinux_nlmsg_perm(sk, skb);
L
Linus Torvalds 已提交
5471 5472
}

5473
static int ipc_alloc_security(struct kern_ipc_perm *perm,
L
Linus Torvalds 已提交
5474 5475 5476 5477
			      u16 sclass)
{
	struct ipc_security_struct *isec;

J
James Morris 已提交
5478
	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
5479 5480 5481 5482
	if (!isec)
		return -ENOMEM;

	isec->sclass = sclass;
5483
	isec->sid = current_sid();
L
Linus Torvalds 已提交
5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499
	perm->security = isec;

	return 0;
}

static void ipc_free_security(struct kern_ipc_perm *perm)
{
	struct ipc_security_struct *isec = perm->security;
	perm->security = NULL;
	kfree(isec);
}

static int msg_msg_alloc_security(struct msg_msg *msg)
{
	struct msg_security_struct *msec;

J
James Morris 已提交
5500
	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
5501 5502 5503 5504 5505 5506 5507 5508 5509 5510 5511 5512 5513 5514 5515 5516 5517 5518
	if (!msec)
		return -ENOMEM;

	msec->sid = SECINITSID_UNLABELED;
	msg->security = msec;

	return 0;
}

static void msg_msg_free_security(struct msg_msg *msg)
{
	struct msg_security_struct *msec = msg->security;

	msg->security = NULL;
	kfree(msec);
}

static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5519
			u32 perms)
L
Linus Torvalds 已提交
5520 5521
{
	struct ipc_security_struct *isec;
5522
	struct common_audit_data ad;
5523
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5524 5525 5526

	isec = ipc_perms->security;

5527
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5528 5529
	ad.u.ipc_id = ipc_perms->key;

5530
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
L
Linus Torvalds 已提交
5531 5532 5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 5544 5545 5546
}

static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
{
	return msg_msg_alloc_security(msg);
}

static void selinux_msg_msg_free_security(struct msg_msg *msg)
{
	msg_msg_free_security(msg);
}

/* message queue security operations */
static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
{
	struct ipc_security_struct *isec;
5547
	struct common_audit_data ad;
5548
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5549 5550
	int rc;

5551
	rc = ipc_alloc_security(&msq->q_perm, SECCLASS_MSGQ);
L
Linus Torvalds 已提交
5552 5553 5554 5555 5556
	if (rc)
		return rc;

	isec = msq->q_perm.security;

5557
	ad.type = LSM_AUDIT_DATA_IPC;
5558
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5559

5560
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5561 5562 5563 5564 5565 5566 5567 5568 5569 5570 5571 5572 5573 5574 5575 5576
			  MSGQ__CREATE, &ad);
	if (rc) {
		ipc_free_security(&msq->q_perm);
		return rc;
	}
	return 0;
}

static void selinux_msg_queue_free_security(struct msg_queue *msq)
{
	ipc_free_security(&msq->q_perm);
}

static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
{
	struct ipc_security_struct *isec;
5577
	struct common_audit_data ad;
5578
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5579 5580 5581

	isec = msq->q_perm.security;

5582
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5583 5584
	ad.u.ipc_id = msq->q_perm.key;

5585
	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5586 5587 5588 5589 5590 5591 5592 5593
			    MSGQ__ASSOCIATE, &ad);
}

static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
{
	int err;
	int perms;

5594
	switch (cmd) {
L
Linus Torvalds 已提交
5595 5596 5597
	case IPC_INFO:
	case MSG_INFO:
		/* No specific object, just general system-wide information. */
5598 5599
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
L
Linus Torvalds 已提交
5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613
	case IPC_STAT:
	case MSG_STAT:
		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
		break;
	case IPC_SET:
		perms = MSGQ__SETATTR;
		break;
	case IPC_RMID:
		perms = MSGQ__DESTROY;
		break;
	default:
		return 0;
	}

5614
	err = ipc_has_perm(&msq->q_perm, perms);
L
Linus Torvalds 已提交
5615 5616 5617 5618 5619 5620 5621
	return err;
}

static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
{
	struct ipc_security_struct *isec;
	struct msg_security_struct *msec;
5622
	struct common_audit_data ad;
5623
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5624 5625 5626 5627 5628 5629 5630 5631 5632 5633 5634 5635 5636
	int rc;

	isec = msq->q_perm.security;
	msec = msg->security;

	/*
	 * First time through, need to assign label to the message
	 */
	if (msec->sid == SECINITSID_UNLABELED) {
		/*
		 * Compute new sid based on current process and
		 * message queue this message will be stored in
		 */
5637
		rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5638
					     NULL, &msec->sid);
L
Linus Torvalds 已提交
5639 5640 5641 5642
		if (rc)
			return rc;
	}

5643
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5644 5645 5646
	ad.u.ipc_id = msq->q_perm.key;

	/* Can this process write to the queue? */
5647
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5648 5649 5650
			  MSGQ__WRITE, &ad);
	if (!rc)
		/* Can this process send the message */
5651 5652
		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
				  MSG__SEND, &ad);
L
Linus Torvalds 已提交
5653 5654
	if (!rc)
		/* Can the message be put in the queue? */
5655 5656
		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
				  MSGQ__ENQUEUE, &ad);
L
Linus Torvalds 已提交
5657 5658 5659 5660 5661 5662 5663 5664 5665 5666

	return rc;
}

static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
				    struct task_struct *target,
				    long type, int mode)
{
	struct ipc_security_struct *isec;
	struct msg_security_struct *msec;
5667
	struct common_audit_data ad;
5668
	u32 sid = task_sid(target);
L
Linus Torvalds 已提交
5669 5670 5671 5672 5673
	int rc;

	isec = msq->q_perm.security;
	msec = msg->security;

5674
	ad.type = LSM_AUDIT_DATA_IPC;
5675
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5676

5677
	rc = avc_has_perm(sid, isec->sid,
L
Linus Torvalds 已提交
5678 5679
			  SECCLASS_MSGQ, MSGQ__READ, &ad);
	if (!rc)
5680
		rc = avc_has_perm(sid, msec->sid,
L
Linus Torvalds 已提交
5681 5682 5683 5684 5685 5686 5687 5688
				  SECCLASS_MSG, MSG__RECEIVE, &ad);
	return rc;
}

/* Shared Memory security operations */
static int selinux_shm_alloc_security(struct shmid_kernel *shp)
{
	struct ipc_security_struct *isec;
5689
	struct common_audit_data ad;
5690
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5691 5692
	int rc;

5693
	rc = ipc_alloc_security(&shp->shm_perm, SECCLASS_SHM);
L
Linus Torvalds 已提交
5694 5695 5696 5697 5698
	if (rc)
		return rc;

	isec = shp->shm_perm.security;

5699
	ad.type = LSM_AUDIT_DATA_IPC;
5700
	ad.u.ipc_id = shp->shm_perm.key;
L
Linus Torvalds 已提交
5701

5702
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5703 5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718
			  SHM__CREATE, &ad);
	if (rc) {
		ipc_free_security(&shp->shm_perm);
		return rc;
	}
	return 0;
}

static void selinux_shm_free_security(struct shmid_kernel *shp)
{
	ipc_free_security(&shp->shm_perm);
}

static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
{
	struct ipc_security_struct *isec;
5719
	struct common_audit_data ad;
5720
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5721 5722 5723

	isec = shp->shm_perm.security;

5724
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5725 5726
	ad.u.ipc_id = shp->shm_perm.key;

5727
	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5728 5729 5730 5731 5732 5733 5734 5735 5736
			    SHM__ASSOCIATE, &ad);
}

/* Note, at this point, shp is locked down */
static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
{
	int perms;
	int err;

5737
	switch (cmd) {
L
Linus Torvalds 已提交
5738 5739 5740
	case IPC_INFO:
	case SHM_INFO:
		/* No specific object, just general system-wide information. */
5741 5742
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
L
Linus Torvalds 已提交
5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760
	case IPC_STAT:
	case SHM_STAT:
		perms = SHM__GETATTR | SHM__ASSOCIATE;
		break;
	case IPC_SET:
		perms = SHM__SETATTR;
		break;
	case SHM_LOCK:
	case SHM_UNLOCK:
		perms = SHM__LOCK;
		break;
	case IPC_RMID:
		perms = SHM__DESTROY;
		break;
	default:
		return 0;
	}

5761
	err = ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5762 5763 5764 5765 5766 5767 5768 5769 5770 5771 5772 5773 5774
	return err;
}

static int selinux_shm_shmat(struct shmid_kernel *shp,
			     char __user *shmaddr, int shmflg)
{
	u32 perms;

	if (shmflg & SHM_RDONLY)
		perms = SHM__READ;
	else
		perms = SHM__READ | SHM__WRITE;

5775
	return ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5776 5777 5778 5779 5780 5781
}

/* Semaphore security operations */
static int selinux_sem_alloc_security(struct sem_array *sma)
{
	struct ipc_security_struct *isec;
5782
	struct common_audit_data ad;
5783
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5784 5785
	int rc;

5786
	rc = ipc_alloc_security(&sma->sem_perm, SECCLASS_SEM);
L
Linus Torvalds 已提交
5787 5788 5789 5790 5791
	if (rc)
		return rc;

	isec = sma->sem_perm.security;

5792
	ad.type = LSM_AUDIT_DATA_IPC;
5793
	ad.u.ipc_id = sma->sem_perm.key;
L
Linus Torvalds 已提交
5794

5795
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5796 5797 5798 5799 5800 5801 5802 5803 5804 5805 5806 5807 5808 5809 5810 5811
			  SEM__CREATE, &ad);
	if (rc) {
		ipc_free_security(&sma->sem_perm);
		return rc;
	}
	return 0;
}

static void selinux_sem_free_security(struct sem_array *sma)
{
	ipc_free_security(&sma->sem_perm);
}

static int selinux_sem_associate(struct sem_array *sma, int semflg)
{
	struct ipc_security_struct *isec;
5812
	struct common_audit_data ad;
5813
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5814 5815 5816

	isec = sma->sem_perm.security;

5817
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5818 5819
	ad.u.ipc_id = sma->sem_perm.key;

5820
	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5821 5822 5823 5824 5825 5826 5827 5828 5829
			    SEM__ASSOCIATE, &ad);
}

/* Note, at this point, sma is locked down */
static int selinux_sem_semctl(struct sem_array *sma, int cmd)
{
	int err;
	u32 perms;

5830
	switch (cmd) {
L
Linus Torvalds 已提交
5831 5832 5833
	case IPC_INFO:
	case SEM_INFO:
		/* No specific object, just general system-wide information. */
5834 5835
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
L
Linus Torvalds 已提交
5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862
	case GETPID:
	case GETNCNT:
	case GETZCNT:
		perms = SEM__GETATTR;
		break;
	case GETVAL:
	case GETALL:
		perms = SEM__READ;
		break;
	case SETVAL:
	case SETALL:
		perms = SEM__WRITE;
		break;
	case IPC_RMID:
		perms = SEM__DESTROY;
		break;
	case IPC_SET:
		perms = SEM__SETATTR;
		break;
	case IPC_STAT:
	case SEM_STAT:
		perms = SEM__GETATTR | SEM__ASSOCIATE;
		break;
	default:
		return 0;
	}

5863
	err = ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875 5876
	return err;
}

static int selinux_sem_semop(struct sem_array *sma,
			     struct sembuf *sops, unsigned nsops, int alter)
{
	u32 perms;

	if (alter)
		perms = SEM__READ | SEM__WRITE;
	else
		perms = SEM__READ;

5877
	return ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5878 5879 5880 5881 5882 5883 5884 5885 5886 5887 5888 5889 5890 5891 5892
}

static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
{
	u32 av = 0;

	av = 0;
	if (flag & S_IRUGO)
		av |= IPC__UNIX_READ;
	if (flag & S_IWUGO)
		av |= IPC__UNIX_WRITE;

	if (av == 0)
		return 0;

5893
	return ipc_has_perm(ipcp, av);
L
Linus Torvalds 已提交
5894 5895
}

5896 5897 5898 5899 5900 5901
static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
{
	struct ipc_security_struct *isec = ipcp->security;
	*secid = isec->sid;
}

5902
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
L
Linus Torvalds 已提交
5903 5904 5905 5906 5907 5908
{
	if (inode)
		inode_doinit_with_dentry(inode, dentry);
}

static int selinux_getprocattr(struct task_struct *p,
5909
			       char *name, char **value)
L
Linus Torvalds 已提交
5910
{
5911
	const struct task_security_struct *__tsec;
5912
	u32 sid;
L
Linus Torvalds 已提交
5913
	int error;
5914
	unsigned len;
L
Linus Torvalds 已提交
5915

5916 5917 5918
	rcu_read_lock();
	__tsec = __task_cred(p)->security;

L
Linus Torvalds 已提交
5919
	if (current != p) {
5920 5921
		error = avc_has_perm(current_sid(), __tsec->sid,
				     SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
L
Linus Torvalds 已提交
5922
		if (error)
5923
			goto bad;
L
Linus Torvalds 已提交
5924 5925 5926
	}

	if (!strcmp(name, "current"))
5927
		sid = __tsec->sid;
L
Linus Torvalds 已提交
5928
	else if (!strcmp(name, "prev"))
5929
		sid = __tsec->osid;
L
Linus Torvalds 已提交
5930
	else if (!strcmp(name, "exec"))
5931
		sid = __tsec->exec_sid;
L
Linus Torvalds 已提交
5932
	else if (!strcmp(name, "fscreate"))
5933
		sid = __tsec->create_sid;
5934
	else if (!strcmp(name, "keycreate"))
5935
		sid = __tsec->keycreate_sid;
5936
	else if (!strcmp(name, "sockcreate"))
5937
		sid = __tsec->sockcreate_sid;
5938 5939 5940 5941
	else {
		error = -EINVAL;
		goto bad;
	}
5942
	rcu_read_unlock();
L
Linus Torvalds 已提交
5943 5944 5945 5946

	if (!sid)
		return 0;

5947 5948 5949 5950
	error = security_sid_to_context(sid, value, &len);
	if (error)
		return error;
	return len;
5951

5952
bad:
5953
	rcu_read_unlock();
5954
	return error;
L
Linus Torvalds 已提交
5955 5956
}

5957
static int selinux_setprocattr(const char *name, void *value, size_t size)
L
Linus Torvalds 已提交
5958 5959
{
	struct task_security_struct *tsec;
D
David Howells 已提交
5960
	struct cred *new;
5961
	u32 mysid = current_sid(), sid = 0, ptsid;
L
Linus Torvalds 已提交
5962 5963 5964 5965 5966 5967 5968
	int error;
	char *str = value;

	/*
	 * Basic control over ability to set these attributes at all.
	 */
	if (!strcmp(name, "exec"))
5969 5970
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETEXEC, NULL);
L
Linus Torvalds 已提交
5971
	else if (!strcmp(name, "fscreate"))
5972 5973
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETFSCREATE, NULL);
5974
	else if (!strcmp(name, "keycreate"))
5975 5976
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETKEYCREATE, NULL);
5977
	else if (!strcmp(name, "sockcreate"))
5978 5979
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETSOCKCREATE, NULL);
L
Linus Torvalds 已提交
5980
	else if (!strcmp(name, "current"))
5981 5982
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETCURRENT, NULL);
L
Linus Torvalds 已提交
5983 5984 5985 5986 5987 5988
	else
		error = -EINVAL;
	if (error)
		return error;

	/* Obtain a SID for the context, if one was specified. */
5989
	if (size && str[0] && str[0] != '\n') {
L
Linus Torvalds 已提交
5990 5991 5992 5993
		if (str[size-1] == '\n') {
			str[size-1] = 0;
			size--;
		}
5994
		error = security_context_to_sid(value, size, &sid, GFP_KERNEL);
5995
		if (error == -EINVAL && !strcmp(name, "fscreate")) {
5996
			if (!has_cap_mac_admin(true)) {
5997 5998 5999 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010
				struct audit_buffer *ab;
				size_t audit_size;

				/* We strip a nul only if it is at the end, otherwise the
				 * context contains a nul and we should audit that */
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
				ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
				audit_log_format(ab, "op=fscreate invalid_context=");
				audit_log_n_untrustedstring(ab, value, audit_size);
				audit_log_end(ab);

6011
				return error;
6012
			}
6013 6014 6015
			error = security_context_to_sid_force(value, size,
							      &sid);
		}
L
Linus Torvalds 已提交
6016 6017 6018 6019
		if (error)
			return error;
	}

D
David Howells 已提交
6020 6021 6022 6023
	new = prepare_creds();
	if (!new)
		return -ENOMEM;

L
Linus Torvalds 已提交
6024 6025 6026
	/* Permission checking based on the specified context is
	   performed during the actual operation (execve,
	   open/mkdir/...), when we know the full context of the
D
David Howells 已提交
6027
	   operation.  See selinux_bprm_set_creds for the execve
L
Linus Torvalds 已提交
6028 6029
	   checks and may_create for the file creation checks. The
	   operation will then fail if the context is not permitted. */
D
David Howells 已提交
6030 6031
	tsec = new->security;
	if (!strcmp(name, "exec")) {
L
Linus Torvalds 已提交
6032
		tsec->exec_sid = sid;
D
David Howells 已提交
6033
	} else if (!strcmp(name, "fscreate")) {
L
Linus Torvalds 已提交
6034
		tsec->create_sid = sid;
D
David Howells 已提交
6035
	} else if (!strcmp(name, "keycreate")) {
6036 6037
		error = avc_has_perm(mysid, sid, SECCLASS_KEY, KEY__CREATE,
				     NULL);
6038
		if (error)
D
David Howells 已提交
6039
			goto abort_change;
6040
		tsec->keycreate_sid = sid;
D
David Howells 已提交
6041
	} else if (!strcmp(name, "sockcreate")) {
6042
		tsec->sockcreate_sid = sid;
D
David Howells 已提交
6043 6044
	} else if (!strcmp(name, "current")) {
		error = -EINVAL;
L
Linus Torvalds 已提交
6045
		if (sid == 0)
D
David Howells 已提交
6046 6047 6048 6049
			goto abort_change;

		/* Only allow single threaded processes to change context */
		error = -EPERM;
6050
		if (!current_is_single_threaded()) {
D
David Howells 已提交
6051 6052 6053
			error = security_bounded_transition(tsec->sid, sid);
			if (error)
				goto abort_change;
6054
		}
L
Linus Torvalds 已提交
6055 6056 6057

		/* Check permissions for the transition. */
		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
6058
				     PROCESS__DYNTRANSITION, NULL);
L
Linus Torvalds 已提交
6059
		if (error)
D
David Howells 已提交
6060
			goto abort_change;
L
Linus Torvalds 已提交
6061 6062 6063

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and fail. */
6064
		ptsid = ptrace_parent_sid();
6065
		if (ptsid != 0) {
D
David Howells 已提交
6066 6067
			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
					     PROCESS__PTRACE, NULL);
L
Linus Torvalds 已提交
6068
			if (error)
D
David Howells 已提交
6069
				goto abort_change;
L
Linus Torvalds 已提交
6070 6071
		}

D
David Howells 已提交
6072 6073 6074 6075 6076 6077 6078
		tsec->sid = sid;
	} else {
		error = -EINVAL;
		goto abort_change;
	}

	commit_creds(new);
L
Linus Torvalds 已提交
6079
	return size;
D
David Howells 已提交
6080 6081 6082 6083

abort_change:
	abort_creds(new);
	return error;
L
Linus Torvalds 已提交
6084 6085
}

6086 6087 6088 6089 6090
static int selinux_ismaclabel(const char *name)
{
	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
}

6091 6092 6093 6094 6095
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
	return security_sid_to_context(secid, secdata, seclen);
}

6096
static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
6097
{
6098
	return security_context_to_sid(secdata, seclen, secid, GFP_KERNEL);
6099 6100
}

6101 6102
static void selinux_release_secctx(char *secdata, u32 seclen)
{
6103
	kfree(secdata);
6104 6105
}

6106 6107 6108 6109
static void selinux_inode_invalidate_secctx(struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;

6110
	spin_lock(&isec->lock);
6111
	isec->initialized = LABEL_INVALID;
6112
	spin_unlock(&isec->lock);
6113 6114
}

6115 6116 6117 6118 6119 6120 6121 6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132 6133 6134 6135 6136 6137 6138 6139 6140
/*
 *	called with inode->i_mutex locked
 */
static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
{
	return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
}

/*
 *	called with inode->i_mutex locked
 */
static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
{
	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
}

static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
{
	int len = 0;
	len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
						ctx, true);
	if (len < 0)
		return len;
	*ctxlen = len;
	return 0;
}
6141 6142
#ifdef CONFIG_KEYS

D
David Howells 已提交
6143
static int selinux_key_alloc(struct key *k, const struct cred *cred,
6144
			     unsigned long flags)
6145
{
D
David Howells 已提交
6146
	const struct task_security_struct *tsec;
6147 6148 6149 6150 6151 6152
	struct key_security_struct *ksec;

	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
	if (!ksec)
		return -ENOMEM;

D
David Howells 已提交
6153 6154 6155
	tsec = cred->security;
	if (tsec->keycreate_sid)
		ksec->sid = tsec->keycreate_sid;
6156
	else
D
David Howells 已提交
6157
		ksec->sid = tsec->sid;
6158

6159
	k->security = ksec;
6160 6161 6162 6163 6164 6165 6166 6167 6168 6169 6170 6171
	return 0;
}

static void selinux_key_free(struct key *k)
{
	struct key_security_struct *ksec = k->security;

	k->security = NULL;
	kfree(ksec);
}

static int selinux_key_permission(key_ref_t key_ref,
D
David Howells 已提交
6172
				  const struct cred *cred,
6173
				  unsigned perm)
6174 6175 6176
{
	struct key *key;
	struct key_security_struct *ksec;
6177
	u32 sid;
6178 6179 6180 6181 6182 6183 6184

	/* if no specific permissions are requested, we skip the
	   permission check. No serious, additional covert channels
	   appear to be created. */
	if (perm == 0)
		return 0;

D
David Howells 已提交
6185
	sid = cred_sid(cred);
6186 6187 6188 6189 6190

	key = key_ref_to_ptr(key_ref);
	ksec = key->security;

	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6191 6192
}

6193 6194 6195 6196 6197 6198 6199 6200 6201 6202 6203 6204 6205
static int selinux_key_getsecurity(struct key *key, char **_buffer)
{
	struct key_security_struct *ksec = key->security;
	char *context = NULL;
	unsigned len;
	int rc;

	rc = security_sid_to_context(ksec->sid, &context, &len);
	if (!rc)
		rc = len;
	*_buffer = context;
	return rc;
}
6206 6207 6208
#endif

#ifdef CONFIG_SECURITY_INFINIBAND
6209 6210 6211 6212 6213 6214 6215 6216
static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
{
	struct common_audit_data ad;
	int err;
	u32 sid = 0;
	struct ib_security_struct *sec = ib_sec;
	struct lsm_ibpkey_audit ibpkey;

6217
	err = sel_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 6228 6229
	if (err)
		return err;

	ad.type = LSM_AUDIT_DATA_IBPKEY;
	ibpkey.subnet_prefix = subnet_prefix;
	ibpkey.pkey = pkey_val;
	ad.u.ibpkey = &ibpkey;
	return avc_has_perm(sec->sid, sid,
			    SECCLASS_INFINIBAND_PKEY,
			    INFINIBAND_PKEY__ACCESS, &ad);
}

6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242 6243 6244 6245 6246 6247 6248 6249 6250 6251 6252
static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
					    u8 port_num)
{
	struct common_audit_data ad;
	int err;
	u32 sid = 0;
	struct ib_security_struct *sec = ib_sec;
	struct lsm_ibendport_audit ibendport;

	err = security_ib_endport_sid(dev_name, port_num, &sid);

	if (err)
		return err;

	ad.type = LSM_AUDIT_DATA_IBENDPORT;
	strncpy(ibendport.dev_name, dev_name, sizeof(ibendport.dev_name));
	ibendport.port = port_num;
	ad.u.ibendport = &ibendport;
	return avc_has_perm(sec->sid, sid,
			    SECCLASS_INFINIBAND_ENDPORT,
			    INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
}

6253 6254 6255
static int selinux_ib_alloc_security(void **ib_sec)
{
	struct ib_security_struct *sec;
6256

6257 6258 6259 6260 6261 6262 6263 6264
	sec = kzalloc(sizeof(*sec), GFP_KERNEL);
	if (!sec)
		return -ENOMEM;
	sec->sid = current_sid();

	*ib_sec = sec;
	return 0;
}
6265

6266 6267 6268 6269
static void selinux_ib_free_security(void *ib_sec)
{
	kfree(ib_sec);
}
6270 6271
#endif

6272 6273 6274 6275 6276 6277 6278 6279 6280 6281 6282 6283 6284 6285 6286 6287 6288 6289 6290 6291 6292 6293 6294 6295 6296 6297 6298 6299 6300 6301 6302 6303 6304 6305 6306
#ifdef CONFIG_BPF_SYSCALL
static int selinux_bpf(int cmd, union bpf_attr *attr,
				     unsigned int size)
{
	u32 sid = current_sid();
	int ret;

	switch (cmd) {
	case BPF_MAP_CREATE:
		ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__MAP_CREATE,
				   NULL);
		break;
	case BPF_PROG_LOAD:
		ret = avc_has_perm(sid, sid, SECCLASS_BPF, BPF__PROG_LOAD,
				   NULL);
		break;
	default:
		ret = 0;
		break;
	}

	return ret;
}

static u32 bpf_map_fmode_to_av(fmode_t fmode)
{
	u32 av = 0;

	if (fmode & FMODE_READ)
		av |= BPF__MAP_READ;
	if (fmode & FMODE_WRITE)
		av |= BPF__MAP_WRITE;
	return av;
}

6307 6308 6309 6310 6311 6312 6313 6314 6315 6316 6317 6318 6319 6320 6321 6322 6323 6324 6325 6326 6327 6328 6329 6330 6331 6332 6333 6334 6335 6336 6337 6338 6339
/* This function will check the file pass through unix socket or binder to see
 * if it is a bpf related object. And apply correspinding checks on the bpf
 * object based on the type. The bpf maps and programs, not like other files and
 * socket, are using a shared anonymous inode inside the kernel as their inode.
 * So checking that inode cannot identify if the process have privilege to
 * access the bpf object and that's why we have to add this additional check in
 * selinux_file_receive and selinux_binder_transfer_files.
 */
static int bpf_fd_pass(struct file *file, u32 sid)
{
	struct bpf_security_struct *bpfsec;
	struct bpf_prog *prog;
	struct bpf_map *map;
	int ret;

	if (file->f_op == &bpf_map_fops) {
		map = file->private_data;
		bpfsec = map->security;
		ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
				   bpf_map_fmode_to_av(file->f_mode), NULL);
		if (ret)
			return ret;
	} else if (file->f_op == &bpf_prog_fops) {
		prog = file->private_data;
		bpfsec = prog->aux->security;
		ret = avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
				   BPF__PROG_RUN, NULL);
		if (ret)
			return ret;
	}
	return 0;
}

6340 6341 6342 6343 6344 6345 6346 6347 6348 6349 6350 6351 6352 6353 6354 6355 6356 6357 6358 6359 6360 6361 6362 6363 6364 6365 6366 6367 6368 6369 6370 6371 6372 6373 6374 6375 6376 6377 6378 6379 6380 6381 6382 6383 6384 6385 6386 6387 6388 6389 6390 6391 6392 6393 6394 6395 6396 6397 6398 6399 6400 6401 6402 6403 6404
static int selinux_bpf_map(struct bpf_map *map, fmode_t fmode)
{
	u32 sid = current_sid();
	struct bpf_security_struct *bpfsec;

	bpfsec = map->security;
	return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
			    bpf_map_fmode_to_av(fmode), NULL);
}

static int selinux_bpf_prog(struct bpf_prog *prog)
{
	u32 sid = current_sid();
	struct bpf_security_struct *bpfsec;

	bpfsec = prog->aux->security;
	return avc_has_perm(sid, bpfsec->sid, SECCLASS_BPF,
			    BPF__PROG_RUN, NULL);
}

static int selinux_bpf_map_alloc(struct bpf_map *map)
{
	struct bpf_security_struct *bpfsec;

	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
	if (!bpfsec)
		return -ENOMEM;

	bpfsec->sid = current_sid();
	map->security = bpfsec;

	return 0;
}

static void selinux_bpf_map_free(struct bpf_map *map)
{
	struct bpf_security_struct *bpfsec = map->security;

	map->security = NULL;
	kfree(bpfsec);
}

static int selinux_bpf_prog_alloc(struct bpf_prog_aux *aux)
{
	struct bpf_security_struct *bpfsec;

	bpfsec = kzalloc(sizeof(*bpfsec), GFP_KERNEL);
	if (!bpfsec)
		return -ENOMEM;

	bpfsec->sid = current_sid();
	aux->security = bpfsec;

	return 0;
}

static void selinux_bpf_prog_free(struct bpf_prog_aux *aux)
{
	struct bpf_security_struct *bpfsec = aux->security;

	aux->security = NULL;
	kfree(bpfsec);
}
#endif

6405
static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
6406 6407 6408 6409 6410 6411 6412 6413 6414 6415 6416 6417 6418 6419 6420 6421 6422 6423 6424 6425 6426 6427 6428 6429 6430 6431 6432 6433 6434 6435 6436 6437 6438 6439 6440
	LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
	LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
	LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
	LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),

	LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
	LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
	LSM_HOOK_INIT(capget, selinux_capget),
	LSM_HOOK_INIT(capset, selinux_capset),
	LSM_HOOK_INIT(capable, selinux_capable),
	LSM_HOOK_INIT(quotactl, selinux_quotactl),
	LSM_HOOK_INIT(quota_on, selinux_quota_on),
	LSM_HOOK_INIT(syslog, selinux_syslog),
	LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),

	LSM_HOOK_INIT(netlink_send, selinux_netlink_send),

	LSM_HOOK_INIT(bprm_set_creds, selinux_bprm_set_creds),
	LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
	LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),

	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
	LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
	LSM_HOOK_INIT(sb_copy_data, selinux_sb_copy_data),
	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
	LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
	LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
	LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
	LSM_HOOK_INIT(sb_mount, selinux_mount),
	LSM_HOOK_INIT(sb_umount, selinux_umount),
	LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
	LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
	LSM_HOOK_INIT(sb_parse_opts_str, selinux_parse_opts_str),

	LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
6441
	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
6442 6443 6444 6445 6446 6447 6448 6449 6450 6451 6452 6453 6454 6455 6456 6457 6458 6459 6460 6461 6462 6463 6464 6465 6466 6467

	LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
	LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
	LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
	LSM_HOOK_INIT(inode_create, selinux_inode_create),
	LSM_HOOK_INIT(inode_link, selinux_inode_link),
	LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
	LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
	LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
	LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
	LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
	LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
	LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
	LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
	LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
	LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
	LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
	LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
	LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
	LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
	LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
	LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
	LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
	LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
	LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
	LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
6468
	LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
6469
	LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
6470 6471 6472 6473 6474 6475 6476 6477 6478 6479 6480 6481 6482 6483 6484 6485

	LSM_HOOK_INIT(file_permission, selinux_file_permission),
	LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
	LSM_HOOK_INIT(file_free_security, selinux_file_free_security),
	LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
	LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
	LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
	LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
	LSM_HOOK_INIT(file_lock, selinux_file_lock),
	LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
	LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
	LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
	LSM_HOOK_INIT(file_receive, selinux_file_receive),

	LSM_HOOK_INIT(file_open, selinux_file_open),

6486
	LSM_HOOK_INIT(task_alloc, selinux_task_alloc),
6487 6488 6489 6490 6491 6492 6493
	LSM_HOOK_INIT(cred_alloc_blank, selinux_cred_alloc_blank),
	LSM_HOOK_INIT(cred_free, selinux_cred_free),
	LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
	LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
	LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
	LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
	LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
6494
	LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
6495 6496 6497 6498 6499 6500 6501
	LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
	LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
	LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
	LSM_HOOK_INIT(task_getsecid, selinux_task_getsecid),
	LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
	LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
	LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
6502
	LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit),
6503 6504 6505 6506 6507 6508 6509 6510 6511 6512 6513 6514 6515 6516 6517 6518 6519 6520 6521 6522 6523 6524 6525 6526 6527 6528 6529 6530 6531 6532 6533 6534 6535 6536 6537 6538 6539 6540 6541 6542 6543 6544
	LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
	LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
	LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
	LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
	LSM_HOOK_INIT(task_kill, selinux_task_kill),
	LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),

	LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
	LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),

	LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
	LSM_HOOK_INIT(msg_msg_free_security, selinux_msg_msg_free_security),

	LSM_HOOK_INIT(msg_queue_alloc_security,
			selinux_msg_queue_alloc_security),
	LSM_HOOK_INIT(msg_queue_free_security, selinux_msg_queue_free_security),
	LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
	LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
	LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
	LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),

	LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
	LSM_HOOK_INIT(shm_free_security, selinux_shm_free_security),
	LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
	LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
	LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),

	LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
	LSM_HOOK_INIT(sem_free_security, selinux_sem_free_security),
	LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
	LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
	LSM_HOOK_INIT(sem_semop, selinux_sem_semop),

	LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),

	LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
	LSM_HOOK_INIT(setprocattr, selinux_setprocattr),

	LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
	LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
	LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
	LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
6545
	LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
6546 6547 6548 6549 6550 6551 6552 6553 6554 6555 6556 6557 6558 6559 6560 6561 6562 6563 6564 6565 6566 6567 6568 6569 6570 6571 6572 6573 6574 6575 6576 6577 6578 6579 6580 6581 6582 6583 6584 6585 6586 6587
	LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
	LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
	LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),

	LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
	LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),

	LSM_HOOK_INIT(socket_create, selinux_socket_create),
	LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
	LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
	LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
	LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
	LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
	LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
	LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
	LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
	LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
	LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
	LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
	LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
	LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
	LSM_HOOK_INIT(socket_getpeersec_stream,
			selinux_socket_getpeersec_stream),
	LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
	LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
	LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
	LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
	LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
	LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
	LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
	LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
	LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
	LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
	LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
	LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
	LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
	LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
	LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security),
	LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
	LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
	LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
6588
#ifdef CONFIG_SECURITY_INFINIBAND
6589
	LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
6590 6591
	LSM_HOOK_INIT(ib_endport_manage_subnet,
		      selinux_ib_endport_manage_subnet),
6592 6593 6594
	LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
	LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
#endif
6595
#ifdef CONFIG_SECURITY_NETWORK_XFRM
6596 6597 6598 6599 6600 6601 6602 6603 6604 6605 6606 6607 6608
	LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
	LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
	LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
	LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
	LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
	LSM_HOOK_INIT(xfrm_state_alloc_acquire,
			selinux_xfrm_state_alloc_acquire),
	LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
	LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
	LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
	LSM_HOOK_INIT(xfrm_state_pol_flow_match,
			selinux_xfrm_state_pol_flow_match),
	LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
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#endif
6610 6611

#ifdef CONFIG_KEYS
6612 6613 6614 6615
	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
	LSM_HOOK_INIT(key_free, selinux_key_free),
	LSM_HOOK_INIT(key_permission, selinux_key_permission),
	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
6616
#endif
6617 6618

#ifdef CONFIG_AUDIT
6619 6620 6621 6622
	LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
	LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
	LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
	LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
6623
#endif
6624 6625 6626 6627 6628 6629 6630 6631 6632 6633

#ifdef CONFIG_BPF_SYSCALL
	LSM_HOOK_INIT(bpf, selinux_bpf),
	LSM_HOOK_INIT(bpf_map, selinux_bpf_map),
	LSM_HOOK_INIT(bpf_prog, selinux_bpf_prog),
	LSM_HOOK_INIT(bpf_map_alloc_security, selinux_bpf_map_alloc),
	LSM_HOOK_INIT(bpf_prog_alloc_security, selinux_bpf_prog_alloc),
	LSM_HOOK_INIT(bpf_map_free_security, selinux_bpf_map_free),
	LSM_HOOK_INIT(bpf_prog_free_security, selinux_bpf_prog_free),
#endif
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};

static __init int selinux_init(void)
{
C
Casey Schaufler 已提交
6638
	if (!security_module_enable("selinux")) {
6639 6640 6641 6642
		selinux_enabled = 0;
		return 0;
	}

L
Linus Torvalds 已提交
6643 6644 6645 6646 6647 6648 6649 6650
	if (!selinux_enabled) {
		printk(KERN_INFO "SELinux:  Disabled at boot.\n");
		return 0;
	}

	printk(KERN_INFO "SELinux:  Initializing.\n");

	/* Set the security state for the initial task. */
D
David Howells 已提交
6651
	cred_init_security();
L
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6652

6653 6654
	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);

6655 6656
	sel_inode_cache = kmem_cache_create("selinux_inode_security",
					    sizeof(struct inode_security_struct),
6657
					    0, SLAB_PANIC, NULL);
6658 6659 6660
	file_security_cache = kmem_cache_create("selinux_file_security",
					    sizeof(struct file_security_struct),
					    0, SLAB_PANIC, NULL);
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	avc_init();

6663
	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
L
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6664

6665 6666 6667
	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
		panic("SELinux: Unable to register AVC netcache callback\n");

6668 6669 6670
	if (avc_add_callback(selinux_lsm_notifier_avc_callback, AVC_CALLBACK_RESET))
		panic("SELinux: Unable to register AVC LSM notifier callback\n");

6671
	if (selinux_enforcing)
6672
		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
6673
	else
6674
		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
6675

L
Linus Torvalds 已提交
6676 6677 6678
	return 0;
}

6679 6680 6681 6682 6683
static void delayed_superblock_init(struct super_block *sb, void *unused)
{
	superblock_doinit(sb, NULL);
}

L
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void selinux_complete_init(void)
{
6686
	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
L
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6687 6688

	/* Set up any superblocks initialized prior to the policy load. */
6689
	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
6690
	iterate_supers(delayed_superblock_init, NULL);
L
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6691 6692 6693 6694 6695 6696
}

/* SELinux requires early initialization in order to label
   all processes and objects when they are created. */
security_initcall(selinux_init);

6697
#if defined(CONFIG_NETFILTER)
L
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6698

6699
static const struct nf_hook_ops selinux_nf_ops[] = {
6700 6701
	{
		.hook =		selinux_ipv4_postroute,
6702
		.pf =		NFPROTO_IPV4,
6703 6704 6705 6706 6707
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv4_forward,
6708
		.pf =		NFPROTO_IPV4,
6709 6710
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
6711 6712 6713
	},
	{
		.hook =		selinux_ipv4_output,
6714
		.pf =		NFPROTO_IPV4,
6715 6716
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
6717
	},
6718
#if IS_ENABLED(CONFIG_IPV6)
6719 6720
	{
		.hook =		selinux_ipv6_postroute,
6721
		.pf =		NFPROTO_IPV6,
6722 6723 6724 6725 6726
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP6_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv6_forward,
6727
		.pf =		NFPROTO_IPV6,
6728 6729
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
6730
	},
6731 6732 6733 6734 6735 6736
	{
		.hook =		selinux_ipv6_output,
		.pf =		NFPROTO_IPV6,
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
	},
L
Linus Torvalds 已提交
6737
#endif	/* IPV6 */
6738
};
L
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6739

6740 6741 6742 6743 6744 6745 6746 6747 6748 6749 6750 6751 6752 6753 6754 6755 6756
static int __net_init selinux_nf_register(struct net *net)
{
	return nf_register_net_hooks(net, selinux_nf_ops,
				     ARRAY_SIZE(selinux_nf_ops));
}

static void __net_exit selinux_nf_unregister(struct net *net)
{
	nf_unregister_net_hooks(net, selinux_nf_ops,
				ARRAY_SIZE(selinux_nf_ops));
}

static struct pernet_operations selinux_net_ops = {
	.init = selinux_nf_register,
	.exit = selinux_nf_unregister,
};

L
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6757 6758
static int __init selinux_nf_ip_init(void)
{
6759
	int err;
L
Linus Torvalds 已提交
6760 6761

	if (!selinux_enabled)
6762
		return 0;
6763 6764 6765

	printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");

6766
	err = register_pernet_subsys(&selinux_net_ops);
6767
	if (err)
6768
		panic("SELinux: register_pernet_subsys: error %d\n", err);
L
Linus Torvalds 已提交
6769

6770
	return 0;
L
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6771 6772 6773 6774 6775 6776
}
__initcall(selinux_nf_ip_init);

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static void selinux_nf_ip_exit(void)
{
6777
	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
L
Linus Torvalds 已提交
6778

6779
	unregister_pernet_subsys(&selinux_net_ops);
L
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6780 6781 6782
}
#endif

6783
#else /* CONFIG_NETFILTER */
L
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6784 6785 6786 6787 6788

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
#define selinux_nf_ip_exit()
#endif

6789
#endif /* CONFIG_NETFILTER */
L
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6790 6791

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
6792 6793
static int selinux_disabled;

L
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6794 6795 6796 6797 6798 6799 6800 6801 6802 6803 6804 6805 6806 6807 6808
int selinux_disable(void)
{
	if (ss_initialized) {
		/* Not permitted after initial policy load. */
		return -EINVAL;
	}

	if (selinux_disabled) {
		/* Only do this once. */
		return -EINVAL;
	}

	printk(KERN_INFO "SELinux:  Disabled at runtime.\n");

	selinux_disabled = 1;
6809
	selinux_enabled = 0;
L
Linus Torvalds 已提交
6810

C
Casey Schaufler 已提交
6811
	security_delete_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));
L
Linus Torvalds 已提交
6812

6813 6814 6815
	/* Try to destroy the avc node cache */
	avc_disable();

L
Linus Torvalds 已提交
6816 6817 6818 6819 6820 6821 6822 6823 6824
	/* Unregister netfilter hooks. */
	selinux_nf_ip_exit();

	/* Unregister selinuxfs. */
	exit_sel_fs();

	return 0;
}
#endif