hooks.c 162.5 KB
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/*
 *  NSA Security-Enhanced Linux (SELinux) security module
 *
 *  This file contains the SELinux hook function implementations.
 *
 *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
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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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 *
 *	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>
#include <linux/sched.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 "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 "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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/*
 * 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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 * get the subjective security ID of the current task
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 */
static inline u32 current_sid(void)
{
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	const struct task_security_struct *tsec = current_security();
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	return tsec->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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	mutex_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);
}

/* The file system's label must be initialized prior to use. */

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static const char *labeling_behaviors[7] = {
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	"uses xattr",
	"uses transition SIDs",
	"uses task SIDs",
	"uses genfs_contexts",
	"not configured for labeling",
	"uses mountpoint labeling",
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	"uses native labeling",
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};

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") ||
		!strcmp(sb->s_type->name, "rootfs");
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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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	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
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		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
		       sb->s_id, sb->s_type->name);
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	sbsec->flags |= SE_SBINITIALIZED;
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	if (selinux_is_sblabel_mnt(sb))
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		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,
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				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;

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

821 822 823 824 825
	if (!sbsec->behavior) {
		/*
		 * Determine the labeling behavior to use for this
		 * filesystem type.
		 */
826
		rc = security_fs_use(sb);
827 828 829 830 831 832
		if (rc) {
			printk(KERN_WARNING
				"%s: security_fs_use(%s) returned %d\n",
					__func__, sb->s_type->name, rc);
			goto out;
		}
833
	}
834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855

	/*
	 * If this is a user namespace mount, no contexts are allowed
	 * on the command line and security labels must be ignored.
	 */
	if (sb->s_user_ns != &init_user_ns) {
		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;
	}

856 857
	/* sets the context of the superblock for the fs being mounted. */
	if (fscontext_sid) {
858
		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
L
Linus Torvalds 已提交
859
		if (rc)
860
			goto out;
L
Linus Torvalds 已提交
861

862
		sbsec->sid = fscontext_sid;
863 864 865 866 867 868 869
	}

	/*
	 * 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.
	 */
870 871 872 873 874
	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
		sbsec->behavior = SECURITY_FS_USE_NATIVE;
		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
	}

875 876
	if (context_sid) {
		if (!fscontext_sid) {
877 878
			rc = may_context_mount_sb_relabel(context_sid, sbsec,
							  cred);
879
			if (rc)
880 881
				goto out;
			sbsec->sid = context_sid;
882
		} else {
883 884
			rc = may_context_mount_inode_relabel(context_sid, sbsec,
							     cred);
885
			if (rc)
886
				goto out;
887
		}
888 889
		if (!rootcontext_sid)
			rootcontext_sid = context_sid;
L
Linus Torvalds 已提交
890

891
		sbsec->mntpoint_sid = context_sid;
892
		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
L
Linus Torvalds 已提交
893 894
	}

895
	if (rootcontext_sid) {
896 897
		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
						     cred);
898
		if (rc)
899
			goto out;
900

901
		root_isec->sid = rootcontext_sid;
902
		root_isec->initialized = LABEL_INITIALIZED;
903 904
	}

905
	if (defcontext_sid) {
906 907
		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
908 909 910 911
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux: defcontext option is "
			       "invalid for this filesystem type\n");
			goto out;
L
Linus Torvalds 已提交
912 913
		}

914 915
		if (defcontext_sid != sbsec->def_sid) {
			rc = may_context_mount_inode_relabel(defcontext_sid,
916
							     sbsec, cred);
917 918 919
			if (rc)
				goto out;
		}
L
Linus Torvalds 已提交
920

921
		sbsec->def_sid = defcontext_sid;
L
Linus Torvalds 已提交
922 923
	}

924
out_set_opts:
925
	rc = sb_finish_set_opts(sb);
L
Linus Torvalds 已提交
926
out:
927
	mutex_unlock(&sbsec->lock);
L
Linus Torvalds 已提交
928
	return rc;
929 930 931
out_double_mount:
	rc = -EINVAL;
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
932
	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
933
	goto out;
L
Linus Torvalds 已提交
934 935
}

936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952
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) {
953 954
		struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
		struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
955 956 957 958 959 960 961 962 963 964 965 966
		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,
967
					struct super_block *newsb)
L
Linus Torvalds 已提交
968
{
969 970
	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
	struct superblock_security_struct *newsbsec = newsb->s_security;
L
Linus Torvalds 已提交
971

972 973 974
	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
975

976 977
	/*
	 * if the parent was able to be mounted it clearly had no special lsm
978
	 * mount options.  thus we can safely deal with this superblock later
979
	 */
980
	if (!ss_initialized)
981
		return 0;
982 983

	/* how can we clone if the old one wasn't set up?? */
984
	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
985

986
	/* if fs is reusing a sb, make sure that the contexts match */
987
	if (newsbsec->flags & SE_SBINITIALIZED)
988
		return selinux_cmp_sb_context(oldsb, newsb);
989

990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003
	mutex_lock(&newsbsec->lock);

	newsbsec->flags = oldsbsec->flags;

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

	if (set_context) {
		u32 sid = oldsbsec->mntpoint_sid;

		if (!set_fscontext)
			newsbsec->sid = sid;
		if (!set_rootcontext) {
1004
			struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
1005 1006 1007
			newisec->sid = sid;
		}
		newsbsec->mntpoint_sid = sid;
L
Linus Torvalds 已提交
1008
	}
1009
	if (set_rootcontext) {
1010 1011
		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
1012

1013
		newisec->sid = oldisec->sid;
L
Linus Torvalds 已提交
1014 1015
	}

1016 1017
	sb_finish_set_opts(newsb);
	mutex_unlock(&newsbsec->lock);
1018
	return 0;
1019 1020
}

1021 1022
static int selinux_parse_opts_str(char *options,
				  struct security_mnt_opts *opts)
1023
{
1024
	char *p;
1025 1026
	char *context = NULL, *defcontext = NULL;
	char *fscontext = NULL, *rootcontext = NULL;
1027
	int rc, num_mnt_opts = 0;
L
Linus Torvalds 已提交
1028

1029
	opts->num_mnt_opts = 0;
L
Linus Torvalds 已提交
1030

1031 1032 1033 1034
	/* Standard string-based options. */
	while ((p = strsep(&options, "|")) != NULL) {
		int token;
		substring_t args[MAX_OPT_ARGS];
L
Linus Torvalds 已提交
1035

1036 1037
		if (!*p)
			continue;
L
Linus Torvalds 已提交
1038

1039
		token = match_token(p, tokens, args);
L
Linus Torvalds 已提交
1040

1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092
		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;
1093 1094
		case Opt_labelsupport:
			break;
1095 1096 1097 1098
		default:
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux:  unknown mount option\n");
			goto out_err;
L
Linus Torvalds 已提交
1099 1100 1101

		}
	}
1102

1103
	rc = -ENOMEM;
1104
	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_KERNEL);
1105 1106 1107
	if (!opts->mnt_opts)
		goto out_err;

1108 1109
	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int),
				       GFP_KERNEL);
1110 1111 1112 1113 1114
	if (!opts->mnt_opts_flags) {
		kfree(opts->mnt_opts);
		goto out_err;
	}

1115
	if (fscontext) {
1116 1117
		opts->mnt_opts[num_mnt_opts] = fscontext;
		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
1118 1119
	}
	if (context) {
1120 1121
		opts->mnt_opts[num_mnt_opts] = context;
		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
1122 1123
	}
	if (rootcontext) {
1124 1125
		opts->mnt_opts[num_mnt_opts] = rootcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
1126 1127
	}
	if (defcontext) {
1128 1129
		opts->mnt_opts[num_mnt_opts] = defcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
1130 1131
	}

1132 1133 1134
	opts->num_mnt_opts = num_mnt_opts;
	return 0;

1135 1136 1137 1138 1139
out_err:
	kfree(context);
	kfree(defcontext);
	kfree(fscontext);
	kfree(rootcontext);
L
Linus Torvalds 已提交
1140 1141
	return rc;
}
1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162
/*
 * 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:
1163
	rc = selinux_set_mnt_opts(sb, &opts, 0, NULL);
1164 1165 1166 1167 1168

out_err:
	security_free_mnt_opts(&opts);
	return rc;
}
L
Linus Torvalds 已提交
1169

A
Adrian Bunk 已提交
1170 1171
static void selinux_write_opts(struct seq_file *m,
			       struct security_mnt_opts *opts)
1172 1173 1174 1175 1176
{
	int i;
	char *prefix;

	for (i = 0; i < opts->num_mnt_opts; i++) {
1177 1178 1179 1180 1181 1182
		char *has_comma;

		if (opts->mnt_opts[i])
			has_comma = strchr(opts->mnt_opts[i], ',');
		else
			has_comma = NULL;
1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196

		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;
1197
		case SBLABEL_MNT:
1198 1199 1200
			seq_putc(m, ',');
			seq_puts(m, LABELSUPP_STR);
			continue;
1201 1202
		default:
			BUG();
1203
			return;
1204 1205 1206 1207 1208 1209
		};
		/* we need a comma before each option */
		seq_putc(m, ',');
		seq_puts(m, prefix);
		if (has_comma)
			seq_putc(m, '\"');
1210
		seq_escape(m, opts->mnt_opts[i], "\"\n\\");
1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221
		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);
1222 1223 1224 1225
	if (rc) {
		/* before policy load we may get EINVAL, don't show anything */
		if (rc == -EINVAL)
			rc = 0;
1226
		return rc;
1227
	}
1228 1229 1230 1231 1232 1233 1234 1235

	selinux_write_opts(m, &opts);

	security_free_mnt_opts(&opts);

	return rc;
}

L
Linus Torvalds 已提交
1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258
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;
}

1259 1260 1261 1262 1263 1264 1265 1266 1267 1268
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
1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284
static inline u16 socket_type_to_security_class(int family, int type, int protocol)
{
	switch (family) {
	case PF_UNIX:
		switch (type) {
		case SOCK_STREAM:
		case SOCK_SEQPACKET:
			return SECCLASS_UNIX_STREAM_SOCKET;
		case SOCK_DGRAM:
			return SECCLASS_UNIX_DGRAM_SOCKET;
		}
		break;
	case PF_INET:
	case PF_INET6:
		switch (type) {
		case SOCK_STREAM:
1285 1286 1287 1288
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
L
Linus Torvalds 已提交
1289
		case SOCK_DGRAM:
1290 1291 1292 1293
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
J
James Morris 已提交
1294 1295
		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
1296
		default:
L
Linus Torvalds 已提交
1297 1298 1299 1300 1301 1302 1303
			return SECCLASS_RAWIP_SOCKET;
		}
		break;
	case PF_NETLINK:
		switch (protocol) {
		case NETLINK_ROUTE:
			return SECCLASS_NETLINK_ROUTE_SOCKET;
1304
		case NETLINK_SOCK_DIAG:
L
Linus Torvalds 已提交
1305 1306 1307 1308 1309 1310 1311
			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;
1312 1313
		case NETLINK_ISCSI:
			return SECCLASS_NETLINK_ISCSI_SOCKET;
L
Linus Torvalds 已提交
1314 1315
		case NETLINK_AUDIT:
			return SECCLASS_NETLINK_AUDIT_SOCKET;
1316 1317 1318 1319 1320 1321
		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
1322 1323
		case NETLINK_DNRTMSG:
			return SECCLASS_NETLINK_DNRT_SOCKET;
1324 1325
		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1326 1327 1328 1329 1330 1331 1332 1333
		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
1334 1335 1336 1337 1338 1339 1340
		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
1341 1342
	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
L
Linus Torvalds 已提交
1343 1344 1345 1346 1347
	}

	return SECCLASS_SOCKET;
}

1348 1349 1350 1351
static int selinux_genfs_get_sid(struct dentry *dentry,
				 u16 tclass,
				 u16 flags,
				 u32 *sid)
L
Linus Torvalds 已提交
1352
{
1353
	int rc;
1354
	struct super_block *sb = dentry->d_sb;
1355
	char *buffer, *path;
L
Linus Torvalds 已提交
1356

1357
	buffer = (char *)__get_free_page(GFP_KERNEL);
L
Linus Torvalds 已提交
1358 1359 1360
	if (!buffer)
		return -ENOMEM;

1361 1362 1363 1364
	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
	if (IS_ERR(path))
		rc = PTR_ERR(path);
	else {
1365 1366 1367 1368 1369 1370 1371 1372
		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++;
			}
1373
		}
1374
		rc = security_genfs_sid(sb->s_type->name, path, tclass, sid);
L
Linus Torvalds 已提交
1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
	}
	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;
	u32 sid;
	struct dentry *dentry;
#define INITCONTEXTLEN 255
	char *context = NULL;
	unsigned len = 0;
	int rc = 0;

1392
	if (isec->initialized == LABEL_INITIALIZED)
L
Linus Torvalds 已提交
1393 1394
		goto out;

1395
	mutex_lock(&isec->lock);
1396
	if (isec->initialized == LABEL_INITIALIZED)
1397
		goto out_unlock;
L
Linus Torvalds 已提交
1398 1399

	sbsec = inode->i_sb->s_security;
1400
	if (!(sbsec->flags & SE_SBINITIALIZED)) {
L
Linus Torvalds 已提交
1401 1402 1403 1404 1405 1406 1407
		/* 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);
1408
		goto out_unlock;
L
Linus Torvalds 已提交
1409 1410 1411
	}

	switch (sbsec->behavior) {
1412 1413
	case SECURITY_FS_USE_NATIVE:
		break;
L
Linus Torvalds 已提交
1414
	case SECURITY_FS_USE_XATTR:
1415
		if (!(inode->i_opflags & IOP_XATTR)) {
L
Linus Torvalds 已提交
1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428
			isec->sid = sbsec->def_sid;
			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) {
1429 1430 1431 1432 1433 1434 1435 1436 1437
			/*
			 * 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.
			 */
1438
			goto out_unlock;
L
Linus Torvalds 已提交
1439 1440 1441
		}

		len = INITCONTEXTLEN;
1442
		context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1443 1444 1445
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
1446
			goto out_unlock;
L
Linus Torvalds 已提交
1447
		}
1448
		context[len] = '\0';
1449
		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
L
Linus Torvalds 已提交
1450
		if (rc == -ERANGE) {
1451 1452
			kfree(context);

L
Linus Torvalds 已提交
1453
			/* Need a larger buffer.  Query for the right size. */
1454
			rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
L
Linus Torvalds 已提交
1455 1456
			if (rc < 0) {
				dput(dentry);
1457
				goto out_unlock;
L
Linus Torvalds 已提交
1458 1459
			}
			len = rc;
1460
			context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1461 1462 1463
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
1464
				goto out_unlock;
L
Linus Torvalds 已提交
1465
			}
1466
			context[len] = '\0';
1467
			rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
L
Linus Torvalds 已提交
1468 1469 1470 1471
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
E
Eric Paris 已提交
1472
				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1473
				       "%d for dev=%s ino=%ld\n", __func__,
L
Linus Torvalds 已提交
1474 1475
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
1476
				goto out_unlock;
L
Linus Torvalds 已提交
1477 1478 1479 1480 1481
			}
			/* Map ENODATA to the default file SID */
			sid = sbsec->def_sid;
			rc = 0;
		} else {
1482
			rc = security_context_to_sid_default(context, rc, &sid,
1483 1484
							     sbsec->def_sid,
							     GFP_NOFS);
L
Linus Torvalds 已提交
1485
			if (rc) {
1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498
				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
1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516
				kfree(context);
				/* Leave with the unlabeled SID */
				rc = 0;
				break;
			}
		}
		kfree(context);
		isec->sid = sid;
		break;
	case SECURITY_FS_USE_TASK:
		isec->sid = isec->task_sid;
		break;
	case SECURITY_FS_USE_TRANS:
		/* Default to the fs SID. */
		isec->sid = sbsec->sid;

		/* Try to obtain a transition SID. */
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1517 1518
		rc = security_transition_sid(isec->task_sid, sbsec->sid,
					     isec->sclass, NULL, &sid);
L
Linus Torvalds 已提交
1519
		if (rc)
1520
			goto out_unlock;
L
Linus Torvalds 已提交
1521 1522
		isec->sid = sid;
		break;
1523 1524 1525
	case SECURITY_FS_USE_MNTPOINT:
		isec->sid = sbsec->mntpoint_sid;
		break;
L
Linus Torvalds 已提交
1526
	default:
1527
		/* Default to the fs superblock SID. */
L
Linus Torvalds 已提交
1528 1529
		isec->sid = sbsec->sid;

1530
		if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) {
1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552
			/* 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)
				goto out_unlock;
			isec->sclass = inode_mode_to_security_class(inode->i_mode);
1553 1554
			rc = selinux_genfs_get_sid(dentry, isec->sclass,
						   sbsec->flags, &sid);
1555 1556 1557 1558
			dput(dentry);
			if (rc)
				goto out_unlock;
			isec->sid = sid;
L
Linus Torvalds 已提交
1559 1560 1561 1562
		}
		break;
	}

1563
	isec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
1564

1565 1566
out_unlock:
	mutex_unlock(&isec->lock);
L
Linus Torvalds 已提交
1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599
out:
	if (isec->sclass == SECCLASS_FILE)
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
	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;
}

D
David Howells 已提交
1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612
/*
 * Check permission between a pair of credentials
 * fork check, ptrace check, etc.
 */
static int cred_has_perm(const struct cred *actor,
			 const struct cred *target,
			 u32 perms)
{
	u32 asid = cred_sid(actor), tsid = cred_sid(target);

	return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
}

1613
/*
1614
 * Check permission between a pair of tasks, e.g. signal checks,
1615 1616
 * fork check, ptrace check, etc.
 * tsk1 is the actor and tsk2 is the target
1617
 * - this uses the default subjective creds of tsk1
1618 1619 1620
 */
static int task_has_perm(const struct task_struct *tsk1,
			 const struct task_struct *tsk2,
L
Linus Torvalds 已提交
1621 1622
			 u32 perms)
{
1623 1624
	const struct task_security_struct *__tsec1, *__tsec2;
	u32 sid1, sid2;
L
Linus Torvalds 已提交
1625

1626 1627 1628 1629 1630
	rcu_read_lock();
	__tsec1 = __task_cred(tsk1)->security;	sid1 = __tsec1->sid;
	__tsec2 = __task_cred(tsk2)->security;	sid2 = __tsec2->sid;
	rcu_read_unlock();
	return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
L
Linus Torvalds 已提交
1631 1632
}

1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648
/*
 * Check permission between current and another task, e.g. signal checks,
 * fork check, ptrace check, etc.
 * current is the actor and tsk2 is the target
 * - this uses current's subjective creds
 */
static int current_has_perm(const struct task_struct *tsk,
			    u32 perms)
{
	u32 sid, tsid;

	sid = current_sid();
	tsid = task_sid(tsk);
	return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
}

1649 1650 1651 1652
#if CAP_LAST_CAP > 63
#error Fix SELinux to handle capabilities > 63.
#endif

L
Linus Torvalds 已提交
1653
/* Check whether a task is allowed to use a capability. */
1654
static int cred_has_capability(const struct cred *cred,
1655
			       int cap, int audit, bool initns)
L
Linus Torvalds 已提交
1656
{
1657
	struct common_audit_data ad;
1658
	struct av_decision avd;
1659
	u16 sclass;
1660
	u32 sid = cred_sid(cred);
1661
	u32 av = CAP_TO_MASK(cap);
1662
	int rc;
L
Linus Torvalds 已提交
1663

1664
	ad.type = LSM_AUDIT_DATA_CAP;
L
Linus Torvalds 已提交
1665 1666
	ad.u.cap = cap;

1667 1668
	switch (CAP_TO_INDEX(cap)) {
	case 0:
1669
		sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1670 1671
		break;
	case 1:
1672
		sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1673 1674 1675 1676 1677
		break;
	default:
		printk(KERN_ERR
		       "SELinux:  out of range capability %d\n", cap);
		BUG();
1678
		return -EINVAL;
1679
	}
1680

1681
	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1682
	if (audit == SECURITY_CAP_AUDIT) {
1683
		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1684 1685 1686
		if (rc2)
			return rc2;
	}
1687
	return rc;
L
Linus Torvalds 已提交
1688 1689 1690 1691 1692 1693
}

/* Check whether a task is allowed to use a system operation. */
static int task_has_system(struct task_struct *tsk,
			   u32 perms)
{
1694
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
1695

1696
	return avc_has_perm(sid, SECINITSID_KERNEL,
L
Linus Torvalds 已提交
1697 1698 1699 1700 1701 1702
			    SECCLASS_SYSTEM, perms, NULL);
}

/* 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). */
1703
static int inode_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1704 1705
			  struct inode *inode,
			  u32 perms,
1706
			  struct common_audit_data *adp)
L
Linus Torvalds 已提交
1707 1708
{
	struct inode_security_struct *isec;
1709
	u32 sid;
L
Linus Torvalds 已提交
1710

1711 1712
	validate_creds(cred);

1713
	if (unlikely(IS_PRIVATE(inode)))
1714 1715
		return 0;

1716
	sid = cred_sid(cred);
L
Linus Torvalds 已提交
1717 1718
	isec = inode->i_security;

1719
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
L
Linus Torvalds 已提交
1720 1721 1722 1723 1724
}

/* 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. */
1725
static inline int dentry_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1726 1727 1728
				  struct dentry *dentry,
				  u32 av)
{
1729
	struct inode *inode = d_backing_inode(dentry);
1730
	struct common_audit_data ad;
1731

1732
	ad.type = LSM_AUDIT_DATA_DENTRY;
E
Eric Paris 已提交
1733
	ad.u.dentry = dentry;
1734
	__inode_security_revalidate(inode, dentry, true);
1735
	return inode_has_perm(cred, inode, av, &ad);
E
Eric Paris 已提交
1736 1737 1738 1739 1740 1741
}

/* 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,
1742
				const struct path *path,
E
Eric Paris 已提交
1743 1744
				u32 av)
{
1745
	struct inode *inode = d_backing_inode(path->dentry);
E
Eric Paris 已提交
1746 1747
	struct common_audit_data ad;

1748
	ad.type = LSM_AUDIT_DATA_PATH;
E
Eric Paris 已提交
1749
	ad.u.path = *path;
1750
	__inode_security_revalidate(inode, path->dentry, true);
1751
	return inode_has_perm(cred, inode, av, &ad);
L
Linus Torvalds 已提交
1752 1753
}

1754 1755 1756 1757 1758 1759 1760
/* 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;

1761 1762
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
1763
	return inode_has_perm(cred, file_inode(file), av, &ad);
1764 1765
}

L
Linus Torvalds 已提交
1766 1767 1768 1769 1770 1771 1772 1773
/* 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. */
1774 1775 1776
static int file_has_perm(const struct cred *cred,
			 struct file *file,
			 u32 av)
L
Linus Torvalds 已提交
1777 1778
{
	struct file_security_struct *fsec = file->f_security;
A
Al Viro 已提交
1779
	struct inode *inode = file_inode(file);
1780
	struct common_audit_data ad;
1781
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1782 1783
	int rc;

1784 1785
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
L
Linus Torvalds 已提交
1786

1787 1788
	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid,
L
Linus Torvalds 已提交
1789 1790 1791 1792
				  SECCLASS_FD,
				  FD__USE,
				  &ad);
		if (rc)
1793
			goto out;
L
Linus Torvalds 已提交
1794 1795 1796
	}

	/* av is zero if only checking access to the descriptor. */
1797
	rc = 0;
L
Linus Torvalds 已提交
1798
	if (av)
1799
		rc = inode_has_perm(cred, inode, av, &ad);
L
Linus Torvalds 已提交
1800

1801 1802
out:
	return rc;
L
Linus Torvalds 已提交
1803 1804
}

1805 1806 1807
/*
 * Determine the label for an inode that might be unioned.
 */
1808 1809 1810 1811 1812
static int
selinux_determine_inode_label(const struct task_security_struct *tsec,
				 struct inode *dir,
				 const struct qstr *name, u16 tclass,
				 u32 *_new_isid)
1813 1814 1815 1816 1817 1818 1819 1820 1821 1822
{
	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 {
1823
		const struct inode_security_struct *dsec = inode_security(dir);
1824 1825 1826 1827 1828 1829 1830
		return security_transition_sid(tsec->sid, dsec->sid, tclass,
					       name, _new_isid);
	}

	return 0;
}

L
Linus Torvalds 已提交
1831 1832 1833 1834 1835
/* Check whether a task can create a file. */
static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
1836
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
1837 1838
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
1839
	u32 sid, newsid;
1840
	struct common_audit_data ad;
L
Linus Torvalds 已提交
1841 1842
	int rc;

1843
	dsec = inode_security(dir);
L
Linus Torvalds 已提交
1844 1845
	sbsec = dir->i_sb->s_security;

1846 1847
	sid = tsec->sid;

1848
	ad.type = LSM_AUDIT_DATA_DENTRY;
1849
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1850

1851
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1852 1853 1854 1855 1856
			  DIR__ADD_NAME | DIR__SEARCH,
			  &ad);
	if (rc)
		return rc;

1857 1858
	rc = selinux_determine_inode_label(current_security(), dir,
					   &dentry->d_name, tclass, &newsid);
1859 1860
	if (rc)
		return rc;
L
Linus Torvalds 已提交
1861

1862
	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
L
Linus Torvalds 已提交
1863 1864 1865 1866 1867 1868 1869 1870
	if (rc)
		return rc;

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

1871 1872 1873 1874
/* Check whether a task can create a key. */
static int may_create_key(u32 ksid,
			  struct task_struct *ctx)
{
1875
	u32 sid = task_sid(ctx);
1876

1877
	return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1878 1879
}

1880 1881 1882
#define MAY_LINK	0
#define MAY_UNLINK	1
#define MAY_RMDIR	2
L
Linus Torvalds 已提交
1883 1884 1885 1886 1887 1888 1889 1890

/* 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;
1891
	struct common_audit_data ad;
1892
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1893 1894 1895
	u32 av;
	int rc;

1896 1897
	dsec = inode_security(dir);
	isec = backing_inode_security(dentry);
L
Linus Torvalds 已提交
1898

1899
	ad.type = LSM_AUDIT_DATA_DENTRY;
1900
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1901 1902 1903

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1904
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918
	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
1919 1920
		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
			__func__, kind);
L
Linus Torvalds 已提交
1921 1922 1923
		return 0;
	}

1924
	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
L
Linus Torvalds 已提交
1925 1926 1927 1928 1929 1930 1931 1932 1933
	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;
1934
	struct common_audit_data ad;
1935
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1936 1937 1938 1939
	u32 av;
	int old_is_dir, new_is_dir;
	int rc;

1940 1941
	old_dsec = inode_security(old_dir);
	old_isec = backing_inode_security(old_dentry);
1942
	old_is_dir = d_is_dir(old_dentry);
1943
	new_dsec = inode_security(new_dir);
L
Linus Torvalds 已提交
1944

1945
	ad.type = LSM_AUDIT_DATA_DENTRY;
L
Linus Torvalds 已提交
1946

1947
	ad.u.dentry = old_dentry;
1948
	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1949 1950 1951
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
1952
	rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1953 1954 1955 1956
			  old_isec->sclass, FILE__RENAME, &ad);
	if (rc)
		return rc;
	if (old_is_dir && new_dir != old_dir) {
1957
		rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1958 1959 1960 1961 1962
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

1963
	ad.u.dentry = new_dentry;
L
Linus Torvalds 已提交
1964
	av = DIR__ADD_NAME | DIR__SEARCH;
1965
	if (d_is_positive(new_dentry))
L
Linus Torvalds 已提交
1966
		av |= DIR__REMOVE_NAME;
1967
	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1968 1969
	if (rc)
		return rc;
1970
	if (d_is_positive(new_dentry)) {
1971
		new_isec = backing_inode_security(new_dentry);
1972
		new_is_dir = d_is_dir(new_dentry);
1973
		rc = avc_has_perm(sid, new_isec->sid,
L
Linus Torvalds 已提交
1974 1975 1976 1977 1978 1979 1980 1981 1982 1983
				  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. */
1984
static int superblock_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1985 1986
			       struct super_block *sb,
			       u32 perms,
1987
			       struct common_audit_data *ad)
L
Linus Torvalds 已提交
1988 1989
{
	struct superblock_security_struct *sbsec;
1990
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1991 1992

	sbsec = sb->s_security;
1993
	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
L
Linus Torvalds 已提交
1994 1995 1996 1997 1998 1999 2000
}

/* 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
2001
	if (!S_ISDIR(mode)) {
L
Linus Torvalds 已提交
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023
		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;
}

2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046
/* 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
2047
/*
2048
 * Convert a file to an access vector and include the correct open
E
Eric Paris 已提交
2049 2050
 * open permission.
 */
2051
static inline u32 open_file_to_av(struct file *file)
E
Eric Paris 已提交
2052
{
2053
	u32 av = file_to_av(file);
E
Eric Paris 已提交
2054

2055 2056 2057
	if (selinux_policycap_openperm)
		av |= FILE__OPEN;

E
Eric Paris 已提交
2058 2059 2060
	return av;
}

L
Linus Torvalds 已提交
2061 2062
/* Hook functions begin here. */

2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106
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;
2107
	struct dentry *dentry = file->f_path.dentry;
2108
	struct inode_security_struct *isec;
2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123
	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;
	}

2124
	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2125 2126
		return 0;

2127
	isec = backing_inode_security(dentry);
2128 2129 2130 2131
	return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
			    &ad);
}

2132
static int selinux_ptrace_access_check(struct task_struct *child,
2133
				     unsigned int mode)
L
Linus Torvalds 已提交
2134
{
2135
	if (mode & PTRACE_MODE_READ) {
2136 2137 2138
		u32 sid = current_sid();
		u32 csid = task_sid(child);
		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
2139 2140
	}

2141
	return current_has_perm(child, PROCESS__PTRACE);
2142 2143 2144 2145 2146
}

static int selinux_ptrace_traceme(struct task_struct *parent)
{
	return task_has_perm(parent, current, PROCESS__PTRACE);
L
Linus Torvalds 已提交
2147 2148 2149
}

static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
2150
			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
L
Linus Torvalds 已提交
2151
{
C
Casey Schaufler 已提交
2152
	return current_has_perm(target, PROCESS__GETCAP);
L
Linus Torvalds 已提交
2153 2154
}

D
David Howells 已提交
2155 2156 2157 2158
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
2159
{
D
David Howells 已提交
2160
	return cred_has_perm(old, new, PROCESS__SETCAP);
L
Linus Torvalds 已提交
2161 2162
}

2163 2164 2165 2166 2167 2168 2169 2170 2171 2172
/*
 * (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.
 */

2173 2174
static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
			   int cap, int audit)
L
Linus Torvalds 已提交
2175
{
2176
	return cred_has_capability(cred, cap, audit, ns == &init_user_ns);
L
Linus Torvalds 已提交
2177 2178 2179 2180
}

static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
{
2181
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2182 2183 2184 2185 2186 2187
	int rc = 0;

	if (!sb)
		return 0;

	switch (cmds) {
2188 2189 2190 2191 2192
	case Q_SYNC:
	case Q_QUOTAON:
	case Q_QUOTAOFF:
	case Q_SETINFO:
	case Q_SETQUOTA:
2193
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2194 2195 2196 2197
		break;
	case Q_GETFMT:
	case Q_GETINFO:
	case Q_GETQUOTA:
2198
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2199 2200 2201 2202
		break;
	default:
		rc = 0;  /* let the kernel handle invalid cmds */
		break;
L
Linus Torvalds 已提交
2203 2204 2205 2206 2207 2208
	}
	return rc;
}

static int selinux_quota_on(struct dentry *dentry)
{
2209 2210
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2211
	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
L
Linus Torvalds 已提交
2212 2213
}

2214
static int selinux_syslog(int type)
L
Linus Torvalds 已提交
2215 2216 2217 2218
{
	int rc;

	switch (type) {
2219 2220
	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
2221 2222
		rc = task_has_system(current, SYSTEM__SYSLOG_READ);
		break;
2223 2224 2225 2226
	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:
2227 2228
		rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
		break;
2229 2230 2231 2232 2233
	case SYSLOG_ACTION_CLOSE:	/* Close log */
	case SYSLOG_ACTION_OPEN:	/* Open log */
	case SYSLOG_ACTION_READ:	/* Read from log */
	case SYSLOG_ACTION_READ_CLEAR:	/* Read/clear last kernel messages */
	case SYSLOG_ACTION_CLEAR:	/* Clear ring buffer */
2234 2235 2236
	default:
		rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
		break;
L
Linus Torvalds 已提交
2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248
	}
	return rc;
}

/*
 * 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.
 */
2249
static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
L
Linus Torvalds 已提交
2250 2251 2252
{
	int rc, cap_sys_admin = 0;

C
Casey Schaufler 已提交
2253
	rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2254
				 SECURITY_CAP_NOAUDIT, true);
L
Linus Torvalds 已提交
2255 2256 2257
	if (rc == 0)
		cap_sys_admin = 1;

C
Casey Schaufler 已提交
2258
	return cap_sys_admin;
L
Linus Torvalds 已提交
2259 2260 2261 2262
}

/* binprm security operations */

2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276
static u32 ptrace_parent_sid(struct task_struct *task)
{
	u32 sid = 0;
	struct task_struct *tracer;

	rcu_read_lock();
	tracer = ptrace_parent(task);
	if (tracer)
		sid = task_sid(tracer);
	rcu_read_unlock();

	return sid;
}

2277 2278 2279 2280 2281
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);
2282
	int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311
	int rc;

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

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

	/*
	 * The only transitions we permit under NNP or nosuid
	 * are 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) {
		/*
		 * 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;
		else
			return -EACCES;
	}
	return 0;
}

2312
static int selinux_bprm_set_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2313
{
2314 2315
	const struct task_security_struct *old_tsec;
	struct task_security_struct *new_tsec;
L
Linus Torvalds 已提交
2316
	struct inode_security_struct *isec;
2317
	struct common_audit_data ad;
A
Al Viro 已提交
2318
	struct inode *inode = file_inode(bprm->file);
L
Linus Torvalds 已提交
2319 2320
	int rc;

2321 2322 2323
	/* SELinux context only depends on initial program or script and not
	 * the script interpreter */
	if (bprm->cred_prepared)
L
Linus Torvalds 已提交
2324 2325
		return 0;

2326 2327
	old_tsec = current_security();
	new_tsec = bprm->cred->security;
2328
	isec = inode_security(inode);
L
Linus Torvalds 已提交
2329 2330

	/* Default to the current task SID. */
2331 2332
	new_tsec->sid = old_tsec->sid;
	new_tsec->osid = old_tsec->sid;
L
Linus Torvalds 已提交
2333

2334
	/* Reset fs, key, and sock SIDs on execve. */
2335 2336 2337
	new_tsec->create_sid = 0;
	new_tsec->keycreate_sid = 0;
	new_tsec->sockcreate_sid = 0;
L
Linus Torvalds 已提交
2338

2339 2340
	if (old_tsec->exec_sid) {
		new_tsec->sid = old_tsec->exec_sid;
L
Linus Torvalds 已提交
2341
		/* Reset exec SID on execve. */
2342
		new_tsec->exec_sid = 0;
2343

2344 2345 2346 2347
		/* 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
2348 2349
	} else {
		/* Check for a default transition on this program. */
2350
		rc = security_transition_sid(old_tsec->sid, isec->sid,
2351 2352
					     SECCLASS_PROCESS, NULL,
					     &new_tsec->sid);
L
Linus Torvalds 已提交
2353 2354
		if (rc)
			return rc;
2355 2356 2357 2358 2359 2360 2361 2362

		/*
		 * 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
2363 2364
	}

2365 2366
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = bprm->file;
L
Linus Torvalds 已提交
2367

2368 2369
	if (new_tsec->sid == old_tsec->sid) {
		rc = avc_has_perm(old_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2370 2371 2372 2373 2374
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		/* Check permissions for the transition. */
2375
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
L
Linus Torvalds 已提交
2376 2377 2378 2379
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

2380
		rc = avc_has_perm(new_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2381 2382 2383 2384
				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
		if (rc)
			return rc;

2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397
		/* 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 */
		if (bprm->unsafe &
		    (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2398
			u32 ptsid = ptrace_parent_sid(current);
2399 2400 2401 2402 2403 2404 2405 2406
			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
2407

2408 2409
		/* Clear any possibly unsafe personality bits on exec: */
		bprm->per_clear |= PER_CLEAR_ON_SETID;
L
Linus Torvalds 已提交
2410 2411 2412 2413 2414
	}

	return 0;
}

2415
static int selinux_bprm_secureexec(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2416
{
2417
	const struct task_security_struct *tsec = current_security();
2418
	u32 sid, osid;
L
Linus Torvalds 已提交
2419 2420
	int atsecure = 0;

2421 2422 2423 2424
	sid = tsec->sid;
	osid = tsec->osid;

	if (osid != sid) {
L
Linus Torvalds 已提交
2425 2426 2427
		/* Enable secure mode for SIDs transitions unless
		   the noatsecure permission is granted between
		   the two SIDs, i.e. ahp returns 0. */
2428
		atsecure = avc_has_perm(osid, sid,
2429 2430
					SECCLASS_PROCESS,
					PROCESS__NOATSECURE, NULL);
L
Linus Torvalds 已提交
2431 2432
	}

C
Casey Schaufler 已提交
2433
	return !!atsecure;
L
Linus Torvalds 已提交
2434 2435
}

A
Al Viro 已提交
2436 2437 2438 2439 2440
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
2441
/* Derived from fs/exec.c:flush_old_files. */
2442 2443
static inline void flush_unauthorized_files(const struct cred *cred,
					    struct files_struct *files)
L
Linus Torvalds 已提交
2444 2445
{
	struct file *file, *devnull = NULL;
2446
	struct tty_struct *tty;
2447
	int drop_tty = 0;
A
Al Viro 已提交
2448
	unsigned n;
L
Linus Torvalds 已提交
2449

2450
	tty = get_current_tty();
L
Linus Torvalds 已提交
2451
	if (tty) {
P
Peter Hurley 已提交
2452
		spin_lock(&tty->files_lock);
2453
		if (!list_empty(&tty->tty_files)) {
N
Nick Piggin 已提交
2454
			struct tty_file_private *file_priv;
2455

L
Linus Torvalds 已提交
2456
			/* Revalidate access to controlling tty.
2457 2458 2459 2460
			   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
2461 2462 2463
			file_priv = list_first_entry(&tty->tty_files,
						struct tty_file_private, list);
			file = file_priv->file;
2464
			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2465
				drop_tty = 1;
L
Linus Torvalds 已提交
2466
		}
P
Peter Hurley 已提交
2467
		spin_unlock(&tty->files_lock);
A
Alan Cox 已提交
2468
		tty_kref_put(tty);
L
Linus Torvalds 已提交
2469
	}
2470 2471 2472
	/* Reset controlling tty. */
	if (drop_tty)
		no_tty();
L
Linus Torvalds 已提交
2473 2474

	/* Revalidate access to inherited open files. */
A
Al Viro 已提交
2475 2476 2477
	n = iterate_fd(files, 0, match_file, cred);
	if (!n) /* none found? */
		return;
L
Linus Torvalds 已提交
2478

A
Al Viro 已提交
2479
	devnull = dentry_open(&selinux_null, O_RDWR, cred);
A
Al Viro 已提交
2480 2481 2482 2483 2484 2485 2486
	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
2487
		fput(devnull);
L
Linus Torvalds 已提交
2488 2489
}

2490 2491 2492 2493
/*
 * 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
2494
{
2495 2496 2497
	struct task_security_struct *new_tsec;
	struct rlimit *rlim, *initrlim;
	int rc, i;
D
David Howells 已提交
2498

2499 2500 2501
	new_tsec = bprm->cred->security;
	if (new_tsec->sid == new_tsec->osid)
		return;
L
Linus Torvalds 已提交
2502

2503 2504
	/* Close files for which the new task SID is not authorized. */
	flush_unauthorized_files(bprm->cred, current->files);
R
Roland McGrath 已提交
2505

2506 2507
	/* Always clear parent death signal on SID transitions. */
	current->pdeath_signal = 0;
R
Roland McGrath 已提交
2508

2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521
	/* 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) {
2522 2523
		/* protect against do_prlimit() */
		task_lock(current);
2524 2525 2526 2527
		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
2528
		}
2529 2530
		task_unlock(current);
		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
L
Linus Torvalds 已提交
2531 2532 2533 2534
	}
}

/*
2535 2536
 * Clean up the process immediately after the installation of new credentials
 * due to exec
L
Linus Torvalds 已提交
2537
 */
2538
static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2539
{
2540
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
2541
	struct itimerval itimer;
2542
	u32 osid, sid;
L
Linus Torvalds 已提交
2543 2544
	int rc, i;

2545 2546 2547 2548
	osid = tsec->osid;
	sid = tsec->sid;

	if (sid == osid)
L
Linus Torvalds 已提交
2549 2550
		return;

2551 2552 2553 2554 2555 2556 2557 2558
	/* 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
2559 2560 2561 2562 2563
	if (rc) {
		memset(&itimer, 0, sizeof itimer);
		for (i = 0; i < 3; i++)
			do_setitimer(i, &itimer, NULL);
		spin_lock_irq(&current->sighand->siglock);
2564 2565 2566
		if (!fatal_signal_pending(current)) {
			flush_sigqueue(&current->pending);
			flush_sigqueue(&current->signal->shared_pending);
2567 2568
			flush_signal_handlers(current, 1);
			sigemptyset(&current->blocked);
2569
			recalc_sigpending();
2570
		}
L
Linus Torvalds 已提交
2571 2572 2573
		spin_unlock_irq(&current->sighand->siglock);
	}

2574 2575
	/* Wake up the parent if it is waiting so that it can recheck
	 * wait permission to the new task SID. */
2576
	read_lock(&tasklist_lock);
2577
	__wake_up_parent(current, current->real_parent);
2578
	read_unlock(&tasklist_lock);
L
Linus Torvalds 已提交
2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602
}

/* 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)
{
2603 2604 2605
	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) ||
2606 2607
		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
2608 2609 2610 2611 2612 2613 2614
}

static inline void take_option(char **to, char *from, int *first, int len)
{
	if (!*first) {
		**to = ',';
		*to += 1;
2615
	} else
L
Linus Torvalds 已提交
2616 2617 2618 2619 2620
		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}

2621 2622
static inline void take_selinux_option(char **to, char *from, int *first,
				       int len)
2623 2624 2625 2626 2627 2628
{
	int current_size = 0;

	if (!*first) {
		**to = '|';
		*to += 1;
2629
	} else
2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641
		*first = 0;

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

2642
static int selinux_sb_copy_data(char *orig, char *copy)
L
Linus Torvalds 已提交
2643 2644 2645 2646
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_curr, *in_end;
	char *sec_curr, *nosec_save, *nosec;
2647
	int open_quote = 0;
L
Linus Torvalds 已提交
2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662

	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 {
2663 2664 2665 2666
		if (*in_end == '"')
			open_quote = !open_quote;
		if ((*in_end == ',' && open_quote == 0) ||
				*in_end == '\0') {
L
Linus Torvalds 已提交
2667 2668 2669
			int len = in_end - in_curr;

			if (selinux_option(in_curr, len))
2670
				take_selinux_option(&sec_curr, in_curr, &fsec, len);
L
Linus Torvalds 已提交
2671 2672 2673 2674 2675 2676 2677
			else
				take_option(&nosec, in_curr, &fnosec, len);

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

2678
	strcpy(in_save, nosec_save);
2679
	free_page((unsigned long)nosec_save);
L
Linus Torvalds 已提交
2680 2681 2682 2683
out:
	return rc;
}

2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717
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;

2718
		if (flags[i] == SBLABEL_MNT)
2719
			continue;
2720
		rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL);
2721
		if (rc) {
2722
			printk(KERN_WARNING "SELinux: security_context_str_to_sid"
2723 2724
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, sb->s_type->name, rc);
2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738
			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;
2739
			root_isec = backing_inode_security(sb->s_root);
2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761

			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 "
2762 2763
	       "during remount (dev %s, type=%s)\n", sb->s_id,
	       sb->s_type->name);
2764 2765 2766
	goto out_free_opts;
}

2767
static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
L
Linus Torvalds 已提交
2768
{
2769
	const struct cred *cred = current_cred();
2770
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2771 2772 2773 2774 2775 2776
	int rc;

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

2777 2778 2779 2780
	/* Allow all mounts performed by the kernel */
	if (flags & MS_KERNMOUNT)
		return 0;

2781
	ad.type = LSM_AUDIT_DATA_DENTRY;
2782
	ad.u.dentry = sb->s_root;
2783
	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
L
Linus Torvalds 已提交
2784 2785
}

2786
static int selinux_sb_statfs(struct dentry *dentry)
L
Linus Torvalds 已提交
2787
{
2788
	const struct cred *cred = current_cred();
2789
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2790

2791
	ad.type = LSM_AUDIT_DATA_DENTRY;
2792
	ad.u.dentry = dentry->d_sb->s_root;
2793
	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
L
Linus Torvalds 已提交
2794 2795
}

A
Al Viro 已提交
2796
static int selinux_mount(const char *dev_name,
A
Al Viro 已提交
2797
			 const struct path *path,
A
Al Viro 已提交
2798
			 const char *type,
2799 2800
			 unsigned long flags,
			 void *data)
L
Linus Torvalds 已提交
2801
{
2802
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2803 2804

	if (flags & MS_REMOUNT)
2805
		return superblock_has_perm(cred, path->dentry->d_sb,
2806
					   FILESYSTEM__REMOUNT, NULL);
L
Linus Torvalds 已提交
2807
	else
E
Eric Paris 已提交
2808
		return path_has_perm(cred, path, FILE__MOUNTON);
L
Linus Torvalds 已提交
2809 2810 2811 2812
}

static int selinux_umount(struct vfsmount *mnt, int flags)
{
2813
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2814

2815
	return superblock_has_perm(cred, mnt->mnt_sb,
2816
				   FILESYSTEM__UNMOUNT, NULL);
L
Linus Torvalds 已提交
2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830
}

/* 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);
}

2831
static int selinux_dentry_init_security(struct dentry *dentry, int mode,
A
Al Viro 已提交
2832
					const struct qstr *name, void **ctx,
2833 2834 2835 2836 2837
					u32 *ctxlen)
{
	u32 newsid;
	int rc;

2838 2839
	rc = selinux_determine_inode_label(current_security(),
					   d_inode(dentry->d_parent), name,
2840 2841 2842 2843
					   inode_mode_to_security_class(mode),
					   &newsid);
	if (rc)
		return rc;
2844 2845 2846 2847

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

2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868
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;
}

2869
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2870 2871
				       const struct qstr *qstr,
				       const char **name,
2872
				       void **value, size_t *len)
2873
{
2874
	const struct task_security_struct *tsec = current_security();
2875
	struct superblock_security_struct *sbsec;
2876
	u32 sid, newsid, clen;
2877
	int rc;
2878
	char *context;
2879 2880 2881

	sbsec = dir->i_sb->s_security;

2882 2883 2884
	sid = tsec->sid;
	newsid = tsec->create_sid;

2885
	rc = selinux_determine_inode_label(current_security(),
2886 2887 2888 2889 2890
		dir, qstr,
		inode_mode_to_security_class(inode->i_mode),
		&newsid);
	if (rc)
		return rc;
2891

2892
	/* Possibly defer initialization to selinux_complete_init. */
2893
	if (sbsec->flags & SE_SBINITIALIZED) {
2894 2895 2896
		struct inode_security_struct *isec = inode->i_security;
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		isec->sid = newsid;
2897
		isec->initialized = LABEL_INITIALIZED;
2898
	}
2899

2900
	if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
2901 2902
		return -EOPNOTSUPP;

2903 2904
	if (name)
		*name = XATTR_SELINUX_SUFFIX;
2905

2906
	if (value && len) {
2907
		rc = security_sid_to_context_force(newsid, &context, &clen);
2908
		if (rc)
2909 2910 2911
			return rc;
		*value = context;
		*len = clen;
2912 2913 2914 2915 2916
	}

	return 0;
}

A
Al Viro 已提交
2917
static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936
{
	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);
}

2937
static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
L
Linus Torvalds 已提交
2938 2939 2940 2941 2942 2943 2944 2945 2946
{
	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
2947
static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
L
Linus Torvalds 已提交
2948 2949 2950 2951 2952
{
	return may_create(dir, dentry, inode_mode_to_security_class(mode));
}

static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2953
				struct inode *new_inode, struct dentry *new_dentry)
L
Linus Torvalds 已提交
2954 2955 2956 2957 2958 2959
{
	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
}

static int selinux_inode_readlink(struct dentry *dentry)
{
2960 2961
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2962
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
2963 2964
}

2965 2966
static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
				     bool rcu)
L
Linus Torvalds 已提交
2967
{
2968
	const struct cred *cred = current_cred();
2969 2970 2971
	struct common_audit_data ad;
	struct inode_security_struct *isec;
	u32 sid;
L
Linus Torvalds 已提交
2972

2973 2974 2975 2976 2977
	validate_creds(cred);

	ad.type = LSM_AUDIT_DATA_DENTRY;
	ad.u.dentry = dentry;
	sid = cred_sid(cred);
2978 2979 2980
	isec = inode_security_rcu(inode, rcu);
	if (IS_ERR(isec))
		return PTR_ERR(isec);
2981 2982 2983

	return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad,
				  rcu ? MAY_NOT_BLOCK : 0);
L
Linus Torvalds 已提交
2984 2985
}

2986 2987
static noinline int audit_inode_permission(struct inode *inode,
					   u32 perms, u32 audited, u32 denied,
2988
					   int result,
2989
					   unsigned flags)
L
Linus Torvalds 已提交
2990
{
2991
	struct common_audit_data ad;
2992 2993 2994
	struct inode_security_struct *isec = inode->i_security;
	int rc;

2995
	ad.type = LSM_AUDIT_DATA_INODE;
2996 2997 2998
	ad.u.inode = inode;

	rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
2999
			    audited, denied, result, &ad, flags);
3000 3001 3002 3003 3004
	if (rc)
		return rc;
	return 0;
}

3005
static int selinux_inode_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
3006
{
3007
	const struct cred *cred = current_cred();
3008 3009
	u32 perms;
	bool from_access;
3010
	unsigned flags = mask & MAY_NOT_BLOCK;
3011 3012 3013 3014 3015
	struct inode_security_struct *isec;
	u32 sid;
	struct av_decision avd;
	int rc, rc2;
	u32 audited, denied;
L
Linus Torvalds 已提交
3016

3017
	from_access = mask & MAY_ACCESS;
3018 3019
	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);

3020 3021
	/* No permission to check.  Existence test. */
	if (!mask)
L
Linus Torvalds 已提交
3022 3023
		return 0;

3024
	validate_creds(cred);
3025

3026 3027
	if (unlikely(IS_PRIVATE(inode)))
		return 0;
3028 3029 3030

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

3031
	sid = cred_sid(cred);
3032 3033 3034
	isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK);
	if (IS_ERR(isec))
		return PTR_ERR(isec);
3035 3036 3037 3038 3039 3040 3041 3042

	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;

3043
	rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
3044 3045 3046
	if (rc2)
		return rc2;
	return rc;
L
Linus Torvalds 已提交
3047 3048 3049 3050
}

static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
3051
	const struct cred *cred = current_cred();
3052
	unsigned int ia_valid = iattr->ia_valid;
3053
	__u32 av = FILE__WRITE;
L
Linus Torvalds 已提交
3054

3055 3056 3057 3058 3059 3060 3061
	/* 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
3062

3063 3064
	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
E
Eric Paris 已提交
3065
		return dentry_has_perm(cred, dentry, FILE__SETATTR);
L
Linus Torvalds 已提交
3066

3067 3068
	if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE)
			&& !(ia_valid & ATTR_FILE))
3069 3070 3071
		av |= FILE__OPEN;

	return dentry_has_perm(cred, dentry, av);
L
Linus Torvalds 已提交
3072 3073
}

3074
static int selinux_inode_getattr(const struct path *path)
L
Linus Torvalds 已提交
3075
{
3076
	return path_has_perm(current_cred(), path, FILE__GETATTR);
L
Linus Torvalds 已提交
3077 3078
}

3079
static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
3080
{
3081 3082
	const struct cred *cred = current_cred();

3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096
	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
3097
	return dentry_has_perm(cred, dentry, FILE__SETATTR);
3098 3099
}

3100 3101
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
3102
{
3103
	struct inode *inode = d_backing_inode(dentry);
3104
	struct inode_security_struct *isec;
L
Linus Torvalds 已提交
3105
	struct superblock_security_struct *sbsec;
3106
	struct common_audit_data ad;
3107
	u32 newsid, sid = current_sid();
L
Linus Torvalds 已提交
3108 3109
	int rc = 0;

3110 3111
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
3112 3113

	sbsec = inode->i_sb->s_security;
3114
	if (!(sbsec->flags & SBLABEL_MNT))
L
Linus Torvalds 已提交
3115 3116
		return -EOPNOTSUPP;

3117
	if (!inode_owner_or_capable(inode))
L
Linus Torvalds 已提交
3118 3119
		return -EPERM;

3120
	ad.type = LSM_AUDIT_DATA_DENTRY;
3121
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
3122

3123
	isec = backing_inode_security(dentry);
3124
	rc = avc_has_perm(sid, isec->sid, isec->sclass,
L
Linus Torvalds 已提交
3125 3126 3127 3128
			  FILE__RELABELFROM, &ad);
	if (rc)
		return rc;

3129
	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
3130
	if (rc == -EINVAL) {
3131 3132 3133 3134 3135 3136 3137
		if (!capable(CAP_MAC_ADMIN)) {
			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 */
3138 3139 3140 3141 3142 3143 3144 3145 3146 3147
			if (value) {
				str = value;
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
			} else {
				str = "";
				audit_size = 0;
			}
3148 3149 3150 3151 3152
			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);

3153
			return rc;
3154
		}
3155 3156
		rc = security_context_to_sid_force(value, size, &newsid);
	}
L
Linus Torvalds 已提交
3157 3158 3159
	if (rc)
		return rc;

3160
	rc = avc_has_perm(sid, newsid, isec->sclass,
L
Linus Torvalds 已提交
3161 3162 3163 3164
			  FILE__RELABELTO, &ad);
	if (rc)
		return rc;

3165
	rc = security_validate_transition(isec->sid, newsid, sid,
3166
					  isec->sclass);
L
Linus Torvalds 已提交
3167 3168 3169 3170 3171 3172 3173 3174 3175 3176
	if (rc)
		return rc;

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

3177
static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3178
					const void *value, size_t size,
3179
					int flags)
L
Linus Torvalds 已提交
3180
{
3181
	struct inode *inode = d_backing_inode(dentry);
3182
	struct inode_security_struct *isec;
L
Linus Torvalds 已提交
3183 3184 3185 3186 3187 3188 3189 3190
	u32 newsid;
	int rc;

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

3191
	rc = security_context_to_sid_force(value, size, &newsid);
L
Linus Torvalds 已提交
3192
	if (rc) {
3193 3194 3195
		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
3196 3197 3198
		return;
	}

3199
	isec = backing_inode_security(dentry);
3200
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
3201
	isec->sid = newsid;
3202
	isec->initialized = LABEL_INITIALIZED;
3203

L
Linus Torvalds 已提交
3204 3205 3206
	return;
}

3207
static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
3208
{
3209 3210
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
3211
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
3212 3213
}

3214
static int selinux_inode_listxattr(struct dentry *dentry)
L
Linus Torvalds 已提交
3215
{
3216 3217
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
3218
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
3219 3220
}

3221
static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
3222
{
3223 3224
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
3225 3226 3227 3228 3229 3230

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

3231
/*
3232
 * Copy the inode security context value to the user.
3233 3234 3235
 *
 * Permission check is handled by selinux_inode_getxattr hook.
 */
3236
static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc)
L
Linus Torvalds 已提交
3237
{
3238 3239 3240
	u32 size;
	int error;
	char *context = NULL;
3241
	struct inode_security_struct *isec;
3242

3243 3244
	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;
3245

3246 3247 3248 3249 3250 3251 3252 3253 3254
	/*
	 * 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.
	 */
C
Casey Schaufler 已提交
3255 3256 3257 3258
	error = cap_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
			    SECURITY_CAP_NOAUDIT);
	if (!error)
		error = cred_has_capability(current_cred(), CAP_MAC_ADMIN,
3259
					    SECURITY_CAP_NOAUDIT, true);
3260
	isec = inode_security(inode);
3261 3262 3263 3264 3265
	if (!error)
		error = security_sid_to_context_force(isec->sid, &context,
						      &size);
	else
		error = security_sid_to_context(isec->sid, &context, &size);
3266 3267 3268 3269 3270 3271 3272 3273 3274 3275
	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
3276 3277 3278
}

static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3279
				     const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
3280
{
3281
	struct inode_security_struct *isec = inode_security_novalidate(inode);
L
Linus Torvalds 已提交
3282 3283 3284 3285 3286 3287 3288 3289 3290
	u32 newsid;
	int rc;

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

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

3291
	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
L
Linus Torvalds 已提交
3292 3293 3294
	if (rc)
		return rc;

3295
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
3296
	isec->sid = newsid;
3297
	isec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308
	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;
}

3309
static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3310
{
3311
	struct inode_security_struct *isec = inode_security_novalidate(inode);
3312 3313 3314
	*secid = isec->sid;
}

3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334
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;
}

3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349
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
3350 3351
/* file security operations */

3352
static int selinux_revalidate_file_permission(struct file *file, int mask)
L
Linus Torvalds 已提交
3353
{
3354
	const struct cred *cred = current_cred();
A
Al Viro 已提交
3355
	struct inode *inode = file_inode(file);
L
Linus Torvalds 已提交
3356 3357 3358 3359 3360

	/* 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;

3361 3362
	return file_has_perm(cred, file,
			     file_mask_to_av(inode->i_mode, mask));
L
Linus Torvalds 已提交
3363 3364
}

3365 3366
static int selinux_file_permission(struct file *file, int mask)
{
A
Al Viro 已提交
3367
	struct inode *inode = file_inode(file);
3368
	struct file_security_struct *fsec = file->f_security;
3369
	struct inode_security_struct *isec;
3370 3371
	u32 sid = current_sid();

3372
	if (!mask)
3373 3374 3375
		/* No permission to check.  Existence test. */
		return 0;

3376
	isec = inode_security(inode);
3377 3378
	if (sid == fsec->sid && fsec->isid == isec->sid &&
	    fsec->pseqno == avc_policy_seqno())
3379
		/* No change since file_open check. */
3380 3381
		return 0;

3382 3383 3384
	return selinux_revalidate_file_permission(file, mask);
}

L
Linus Torvalds 已提交
3385 3386 3387 3388 3389 3390 3391 3392 3393 3394
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);
}

3395 3396 3397 3398
/*
 * Check whether a task has the ioctl permission and cmd
 * operation to an inode.
 */
3399
static int ioctl_has_perm(const struct cred *cred, struct file *file,
3400 3401 3402 3403 3404
		u32 requested, u16 cmd)
{
	struct common_audit_data ad;
	struct file_security_struct *fsec = file->f_security;
	struct inode *inode = file_inode(file);
3405
	struct inode_security_struct *isec;
3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428
	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;

3429
	isec = inode_security(inode);
3430 3431 3432 3433 3434 3435
	rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
			requested, driver, xperm, &ad);
out:
	return rc;
}

L
Linus Torvalds 已提交
3436 3437 3438
static int selinux_file_ioctl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3439
	const struct cred *cred = current_cred();
3440
	int error = 0;
L
Linus Torvalds 已提交
3441

3442 3443 3444 3445 3446 3447 3448
	switch (cmd) {
	case FIONREAD:
	/* fall through */
	case FIBMAP:
	/* fall through */
	case FIGETBSZ:
	/* fall through */
3449
	case FS_IOC_GETFLAGS:
3450
	/* fall through */
3451
	case FS_IOC_GETVERSION:
3452 3453
		error = file_has_perm(cred, file, FILE__GETATTR);
		break;
L
Linus Torvalds 已提交
3454

3455
	case FS_IOC_SETFLAGS:
3456
	/* fall through */
3457
	case FS_IOC_SETVERSION:
3458 3459 3460 3461 3462 3463 3464 3465 3466
		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
3467

3468 3469
	case KDSKBENT:
	case KDSKBSENT:
3470
		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3471
					    SECURITY_CAP_AUDIT, true);
3472 3473 3474 3475 3476 3477
		break;

	/* default case assumes that the command will go
	 * to the file's ioctl() function.
	 */
	default:
3478
		error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3479 3480
	}
	return error;
L
Linus Torvalds 已提交
3481 3482
}

3483 3484
static int default_noexec;

L
Linus Torvalds 已提交
3485 3486
static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
3487
	const struct cred *cred = current_cred();
D
David Howells 已提交
3488
	int rc = 0;
3489

3490
	if (default_noexec &&
3491 3492
	    (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
				   (!shared && (prot & PROT_WRITE)))) {
L
Linus Torvalds 已提交
3493 3494 3495 3496 3497
		/*
		 * We are making executable an anonymous mapping or a
		 * private file mapping that will also be writable.
		 * This has an additional check.
		 */
D
David Howells 已提交
3498
		rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
L
Linus Torvalds 已提交
3499
		if (rc)
D
David Howells 已提交
3500
			goto error;
L
Linus Torvalds 已提交
3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513
	}

	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;

3514
		return file_has_perm(cred, file, av);
L
Linus Torvalds 已提交
3515
	}
D
David Howells 已提交
3516 3517 3518

error:
	return rc;
L
Linus Torvalds 已提交
3519 3520
}

3521
static int selinux_mmap_addr(unsigned long addr)
L
Linus Torvalds 已提交
3522
{
C
Casey Schaufler 已提交
3523
	int rc = 0;
L
Linus Torvalds 已提交
3524

3525
	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3526
		u32 sid = current_sid();
3527 3528
		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
				  MEMPROTECT__MMAP_ZERO, NULL);
3529 3530
	}

3531
	return rc;
3532
}
L
Linus Torvalds 已提交
3533

3534 3535 3536
static int selinux_mmap_file(struct file *file, unsigned long reqprot,
			     unsigned long prot, unsigned long flags)
{
L
Linus Torvalds 已提交
3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547
	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)
{
3548
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3549 3550 3551 3552

	if (selinux_checkreqprot)
		prot = reqprot;

3553 3554
	if (default_noexec &&
	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3555
		int rc = 0;
3556 3557
		if (vma->vm_start >= vma->vm_mm->start_brk &&
		    vma->vm_end <= vma->vm_mm->brk) {
D
David Howells 已提交
3558
			rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3559
		} else if (!vma->vm_file &&
3560 3561
			   ((vma->vm_start <= vma->vm_mm->start_stack &&
			     vma->vm_end >= vma->vm_mm->start_stack) ||
3562
			    vma_is_stack_for_current(vma))) {
3563
			rc = current_has_perm(current, PROCESS__EXECSTACK);
3564 3565 3566 3567 3568 3569 3570 3571
		} 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
3572
			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3573
		}
3574 3575 3576
		if (rc)
			return rc;
	}
L
Linus Torvalds 已提交
3577 3578 3579 3580 3581 3582

	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)
{
3583 3584 3585
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, FILE__LOCK);
L
Linus Torvalds 已提交
3586 3587 3588 3589 3590
}

static int selinux_file_fcntl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3591
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3592 3593 3594
	int err = 0;

	switch (cmd) {
3595 3596
	case F_SETFL:
		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3597
			err = file_has_perm(cred, file, FILE__WRITE);
L
Linus Torvalds 已提交
3598
			break;
3599 3600 3601 3602 3603 3604 3605
		}
		/* fall through */
	case F_SETOWN:
	case F_SETSIG:
	case F_GETFL:
	case F_GETOWN:
	case F_GETSIG:
3606
	case F_GETOWNER_UIDS:
3607
		/* Just check FD__USE permission */
3608
		err = file_has_perm(cred, file, 0);
3609 3610 3611 3612
		break;
	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
3613 3614 3615
	case F_OFD_GETLK:
	case F_OFD_SETLK:
	case F_OFD_SETLKW:
L
Linus Torvalds 已提交
3616
#if BITS_PER_LONG == 32
3617 3618 3619
	case F_GETLK64:
	case F_SETLK64:
	case F_SETLKW64:
L
Linus Torvalds 已提交
3620
#endif
3621
		err = file_has_perm(cred, file, FILE__LOCK);
3622
		break;
L
Linus Torvalds 已提交
3623 3624 3625 3626 3627
	}

	return err;
}

3628
static void selinux_file_set_fowner(struct file *file)
L
Linus Torvalds 已提交
3629 3630 3631 3632
{
	struct file_security_struct *fsec;

	fsec = file->f_security;
3633
	fsec->fown_sid = current_sid();
L
Linus Torvalds 已提交
3634 3635 3636 3637 3638
}

static int selinux_file_send_sigiotask(struct task_struct *tsk,
				       struct fown_struct *fown, int signum)
{
3639
	struct file *file;
3640
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
3641 3642 3643 3644
	u32 perm;
	struct file_security_struct *fsec;

	/* struct fown_struct is never outside the context of a struct file */
3645
	file = container_of(fown, struct file, f_owner);
L
Linus Torvalds 已提交
3646 3647 3648 3649 3650 3651 3652 3653

	fsec = file->f_security;

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

3654
	return avc_has_perm(fsec->fown_sid, sid,
L
Linus Torvalds 已提交
3655 3656 3657 3658 3659
			    SECCLASS_PROCESS, perm, NULL);
}

static int selinux_file_receive(struct file *file)
{
3660 3661 3662
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, file_to_av(file));
L
Linus Torvalds 已提交
3663 3664
}

3665
static int selinux_file_open(struct file *file, const struct cred *cred)
3666 3667 3668
{
	struct file_security_struct *fsec;
	struct inode_security_struct *isec;
D
David Howells 已提交
3669

3670
	fsec = file->f_security;
3671
	isec = inode_security(file_inode(file));
3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688
	/*
	 * 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.
	 */
3689
	return file_path_has_perm(cred, file, open_file_to_av(file));
3690 3691
}

L
Linus Torvalds 已提交
3692 3693 3694 3695
/* task security operations */

static int selinux_task_create(unsigned long clone_flags)
{
3696
	return current_has_perm(current, PROCESS__FORK);
L
Linus Torvalds 已提交
3697 3698
}

3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713
/*
 * 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
3714 3715 3716 3717
/*
 * 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
3718
{
D
David Howells 已提交
3719
	struct task_security_struct *tsec = cred->security;
3720

3721 3722 3723 3724 3725
	/*
	 * 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);
3726
	cred->security = (void *) 0x7UL;
D
David Howells 已提交
3727 3728
	kfree(tsec);
}
L
Linus Torvalds 已提交
3729

D
David Howells 已提交
3730 3731 3732 3733 3734 3735 3736 3737
/*
 * 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
3738

D
David Howells 已提交
3739
	old_tsec = old->security;
L
Linus Torvalds 已提交
3740

D
David Howells 已提交
3741 3742 3743
	tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
	if (!tsec)
		return -ENOMEM;
L
Linus Torvalds 已提交
3744

D
David Howells 已提交
3745
	new->security = tsec;
L
Linus Torvalds 已提交
3746 3747 3748
	return 0;
}

3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759
/*
 * 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;
}

3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788
/*
 * 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)
{
3789
	struct inode_security_struct *isec = inode_security(inode);
3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800
	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;
3801
	return ret;
3802 3803
}

3804
static int selinux_kernel_module_request(char *kmod_name)
3805
{
3806 3807 3808 3809 3810
	u32 sid;
	struct common_audit_data ad;

	sid = task_sid(current);

3811
	ad.type = LSM_AUDIT_DATA_KMOD;
3812 3813 3814 3815
	ad.u.kmod_name = kmod_name;

	return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
			    SYSTEM__MODULE_REQUEST, &ad);
3816 3817
}

3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831
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 */
3832

3833 3834
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
3835 3836 3837 3838 3839 3840 3841 3842

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

3843
	isec = inode_security(file_inode(file));
3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863
	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
3864 3865
static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
{
3866
	return current_has_perm(p, PROCESS__SETPGID);
L
Linus Torvalds 已提交
3867 3868 3869 3870
}

static int selinux_task_getpgid(struct task_struct *p)
{
3871
	return current_has_perm(p, PROCESS__GETPGID);
L
Linus Torvalds 已提交
3872 3873 3874 3875
}

static int selinux_task_getsid(struct task_struct *p)
{
3876
	return current_has_perm(p, PROCESS__GETSESSION);
L
Linus Torvalds 已提交
3877 3878
}

3879 3880
static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
{
3881
	*secid = task_sid(p);
3882 3883
}

L
Linus Torvalds 已提交
3884 3885
static int selinux_task_setnice(struct task_struct *p, int nice)
{
3886
	return current_has_perm(p, PROCESS__SETSCHED);
L
Linus Torvalds 已提交
3887 3888
}

3889 3890
static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
3891
	return current_has_perm(p, PROCESS__SETSCHED);
3892 3893
}

3894 3895
static int selinux_task_getioprio(struct task_struct *p)
{
3896
	return current_has_perm(p, PROCESS__GETSCHED);
3897 3898
}

3899 3900
static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
		struct rlimit *new_rlim)
L
Linus Torvalds 已提交
3901
{
3902
	struct rlimit *old_rlim = p->signal->rlim + resource;
L
Linus Torvalds 已提交
3903 3904 3905 3906

	/* 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
3907
	   upon context transitions.  See selinux_bprm_committing_creds. */
L
Linus Torvalds 已提交
3908
	if (old_rlim->rlim_max != new_rlim->rlim_max)
3909
		return current_has_perm(p, PROCESS__SETRLIMIT);
L
Linus Torvalds 已提交
3910 3911 3912 3913

	return 0;
}

3914
static int selinux_task_setscheduler(struct task_struct *p)
L
Linus Torvalds 已提交
3915
{
3916
	return current_has_perm(p, PROCESS__SETSCHED);
L
Linus Torvalds 已提交
3917 3918 3919 3920
}

static int selinux_task_getscheduler(struct task_struct *p)
{
3921
	return current_has_perm(p, PROCESS__GETSCHED);
L
Linus Torvalds 已提交
3922 3923
}

3924 3925
static int selinux_task_movememory(struct task_struct *p)
{
3926
	return current_has_perm(p, PROCESS__SETSCHED);
3927 3928
}

3929 3930
static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
				int sig, u32 secid)
L
Linus Torvalds 已提交
3931 3932 3933 3934 3935 3936 3937 3938
{
	u32 perm;
	int rc;

	if (!sig)
		perm = PROCESS__SIGNULL; /* null signal; existence test */
	else
		perm = signal_to_av(sig);
3939
	if (secid)
3940 3941
		rc = avc_has_perm(secid, task_sid(p),
				  SECCLASS_PROCESS, perm, NULL);
3942
	else
3943
		rc = current_has_perm(p, perm);
3944
	return rc;
L
Linus Torvalds 已提交
3945 3946 3947 3948
}

static int selinux_task_wait(struct task_struct *p)
{
3949
	return task_has_perm(p, current, PROCESS__SIGCHLD);
L
Linus Torvalds 已提交
3950 3951 3952 3953 3954 3955
}

static void selinux_task_to_inode(struct task_struct *p,
				  struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
3956
	u32 sid = task_sid(p);
L
Linus Torvalds 已提交
3957

3958
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3959
	isec->sid = sid;
3960
	isec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
3961 3962 3963
}

/* Returns error only if unable to parse addresses */
3964
static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3965
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
3966 3967 3968 3969
{
	int offset, ihlen, ret = -EINVAL;
	struct iphdr _iph, *ih;

3970
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
3971 3972 3973 3974 3975 3976 3977 3978
	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
	if (ih == NULL)
		goto out;

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

3979 3980
	ad->u.net->v4info.saddr = ih->saddr;
	ad->u.net->v4info.daddr = ih->daddr;
L
Linus Torvalds 已提交
3981 3982
	ret = 0;

3983 3984 3985
	if (proto)
		*proto = ih->protocol;

L
Linus Torvalds 已提交
3986
	switch (ih->protocol) {
3987 3988
	case IPPROTO_TCP: {
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
3989

3990 3991
		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;
L
Linus Torvalds 已提交
3992 3993 3994 3995 3996 3997

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

3998 3999
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
4000
		break;
4001 4002 4003 4004 4005 4006 4007 4008
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

L
Linus Torvalds 已提交
4009
		offset += ihlen;
4010
		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
L
Linus Torvalds 已提交
4011
		if (uh == NULL)
4012
			break;
L
Linus Torvalds 已提交
4013

4014 4015
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
4016 4017
		break;
	}
L
Linus Torvalds 已提交
4018

J
James Morris 已提交
4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029
	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;

4030 4031
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
4032
		break;
4033
	}
J
James Morris 已提交
4034

4035 4036 4037
	default:
		break;
	}
L
Linus Torvalds 已提交
4038 4039 4040 4041
out:
	return ret;
}

4042
#if IS_ENABLED(CONFIG_IPV6)
L
Linus Torvalds 已提交
4043 4044

/* Returns error only if unable to parse addresses */
4045
static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4046
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
4047 4048 4049 4050
{
	u8 nexthdr;
	int ret = -EINVAL, offset;
	struct ipv6hdr _ipv6h, *ip6;
4051
	__be16 frag_off;
L
Linus Torvalds 已提交
4052

4053
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
4054 4055 4056 4057
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		goto out;

4058 4059
	ad->u.net->v6info.saddr = ip6->saddr;
	ad->u.net->v6info.daddr = ip6->daddr;
L
Linus Torvalds 已提交
4060 4061 4062 4063
	ret = 0;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
4064
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
L
Linus Torvalds 已提交
4065 4066 4067
	if (offset < 0)
		goto out;

4068 4069 4070
	if (proto)
		*proto = nexthdr;

L
Linus Torvalds 已提交
4071 4072
	switch (nexthdr) {
	case IPPROTO_TCP: {
4073
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
4074 4075 4076 4077 4078

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

4079 4080
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
4081 4082 4083 4084 4085 4086 4087 4088 4089 4090
		break;
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

4091 4092
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
L
Linus Torvalds 已提交
4093 4094 4095
		break;
	}

J
James Morris 已提交
4096 4097 4098 4099 4100 4101 4102
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

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

4103 4104
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
4105
		break;
4106
	}
J
James Morris 已提交
4107

L
Linus Torvalds 已提交
4108 4109 4110 4111 4112 4113 4114 4115 4116 4117
	/* includes fragments */
	default:
		break;
	}
out:
	return ret;
}

#endif /* IPV6 */

4118
static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4119
			     char **_addrp, int src, u8 *proto)
L
Linus Torvalds 已提交
4120
{
4121 4122
	char *addrp;
	int ret;
L
Linus Torvalds 已提交
4123

4124
	switch (ad->u.net->family) {
L
Linus Torvalds 已提交
4125
	case PF_INET:
4126
		ret = selinux_parse_skb_ipv4(skb, ad, proto);
4127 4128
		if (ret)
			goto parse_error;
4129 4130
		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
				       &ad->u.net->v4info.daddr);
4131
		goto okay;
L
Linus Torvalds 已提交
4132

4133
#if IS_ENABLED(CONFIG_IPV6)
L
Linus Torvalds 已提交
4134
	case PF_INET6:
4135
		ret = selinux_parse_skb_ipv6(skb, ad, proto);
4136 4137
		if (ret)
			goto parse_error;
4138 4139
		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
				       &ad->u.net->v6info.daddr);
4140
		goto okay;
L
Linus Torvalds 已提交
4141 4142
#endif	/* IPV6 */
	default:
4143 4144
		addrp = NULL;
		goto okay;
L
Linus Torvalds 已提交
4145 4146
	}

4147 4148 4149 4150
parse_error:
	printk(KERN_WARNING
	       "SELinux: failure in selinux_parse_skb(),"
	       " unable to parse packet\n");
L
Linus Torvalds 已提交
4151
	return ret;
4152 4153 4154 4155 4156

okay:
	if (_addrp)
		*_addrp = addrp;
	return 0;
L
Linus Torvalds 已提交
4157 4158
}

4159
/**
4160
 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4161
 * @skb: the packet
4162
 * @family: protocol family
4163
 * @sid: the packet's peer label SID
4164 4165
 *
 * Description:
4166 4167 4168 4169 4170 4171
 * 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.
4172 4173
 *
 */
4174
static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4175
{
4176
	int err;
4177 4178
	u32 xfrm_sid;
	u32 nlbl_sid;
4179
	u32 nlbl_type;
4180

4181
	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4182 4183 4184 4185 4186
	if (unlikely(err))
		return -EACCES;
	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
	if (unlikely(err))
		return -EACCES;
4187

4188 4189 4190 4191 4192
	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");
4193
		return -EACCES;
4194
	}
4195 4196

	return 0;
4197 4198
}

4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222
/**
 * 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
4223
/* socket security operations */
4224

4225 4226
static int socket_sockcreate_sid(const struct task_security_struct *tsec,
				 u16 secclass, u32 *socksid)
4227
{
4228 4229 4230 4231 4232 4233 4234
	if (tsec->sockcreate_sid > SECSID_NULL) {
		*socksid = tsec->sockcreate_sid;
		return 0;
	}

	return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
				       socksid);
4235 4236
}

4237
static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
L
Linus Torvalds 已提交
4238
{
4239
	struct sk_security_struct *sksec = sk->sk_security;
4240
	struct common_audit_data ad;
4241
	struct lsm_network_audit net = {0,};
4242
	u32 tsid = task_sid(task);
L
Linus Torvalds 已提交
4243

4244 4245
	if (sksec->sid == SECINITSID_KERNEL)
		return 0;
L
Linus Torvalds 已提交
4246

4247
	ad.type = LSM_AUDIT_DATA_NET;
4248 4249
	ad.u.net = &net;
	ad.u.net->sk = sk;
L
Linus Torvalds 已提交
4250

4251
	return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
L
Linus Torvalds 已提交
4252 4253 4254 4255 4256
}

static int selinux_socket_create(int family, int type,
				 int protocol, int kern)
{
4257
	const struct task_security_struct *tsec = current_security();
4258
	u32 newsid;
4259
	u16 secclass;
4260
	int rc;
L
Linus Torvalds 已提交
4261 4262

	if (kern)
4263
		return 0;
4264 4265

	secclass = socket_type_to_security_class(family, type, protocol);
4266 4267 4268 4269
	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
	if (rc)
		return rc;

4270
	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
L
Linus Torvalds 已提交
4271 4272
}

V
Venkat Yekkirala 已提交
4273 4274
static int selinux_socket_post_create(struct socket *sock, int family,
				      int type, int protocol, int kern)
L
Linus Torvalds 已提交
4275
{
4276
	const struct task_security_struct *tsec = current_security();
4277
	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4278
	struct sk_security_struct *sksec;
4279 4280
	int err = 0;

4281 4282
	isec->sclass = socket_type_to_security_class(family, type, protocol);

4283 4284
	if (kern)
		isec->sid = SECINITSID_KERNEL;
4285 4286 4287 4288 4289
	else {
		err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
		if (err)
			return err;
	}
4290

4291
	isec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
4292

4293 4294 4295
	if (sock->sk) {
		sksec = sock->sk->sk_security;
		sksec->sid = isec->sid;
4296
		sksec->sclass = isec->sclass;
4297
		err = selinux_netlbl_socket_post_create(sock->sk, family);
4298 4299
	}

V
Venkat Yekkirala 已提交
4300
	return err;
L
Linus Torvalds 已提交
4301 4302 4303 4304 4305 4306 4307 4308
}

/* 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)
{
4309
	struct sock *sk = sock->sk;
L
Linus Torvalds 已提交
4310 4311 4312
	u16 family;
	int err;

4313
	err = sock_has_perm(current, sk, SOCKET__BIND);
L
Linus Torvalds 已提交
4314 4315 4316 4317 4318
	if (err)
		goto out;

	/*
	 * If PF_INET or PF_INET6, check name_bind permission for the port.
4319 4320
	 * Multiple address binding for SCTP is not supported yet: we just
	 * check the first address now.
L
Linus Torvalds 已提交
4321
	 */
4322
	family = sk->sk_family;
L
Linus Torvalds 已提交
4323 4324
	if (family == PF_INET || family == PF_INET6) {
		char *addrp;
4325
		struct sk_security_struct *sksec = sk->sk_security;
4326
		struct common_audit_data ad;
4327
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4328 4329 4330
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
4331
		u32 sid, node_perm;
L
Linus Torvalds 已提交
4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342

		if (family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
			snum = ntohs(addr4->sin_port);
			addrp = (char *)&addr4->sin_addr.s_addr;
		} else {
			addr6 = (struct sockaddr_in6 *)address;
			snum = ntohs(addr6->sin6_port);
			addrp = (char *)&addr6->sin6_addr.s6_addr;
		}

4343 4344 4345
		if (snum) {
			int low, high;

4346
			inet_get_local_port_range(sock_net(sk), &low, &high);
4347 4348

			if (snum < max(PROT_SOCK, low) || snum > high) {
P
Paul Moore 已提交
4349 4350
				err = sel_netport_sid(sk->sk_protocol,
						      snum, &sid);
4351 4352
				if (err)
					goto out;
4353
				ad.type = LSM_AUDIT_DATA_NET;
4354 4355 4356
				ad.u.net = &net;
				ad.u.net->sport = htons(snum);
				ad.u.net->family = family;
4357 4358
				err = avc_has_perm(sksec->sid, sid,
						   sksec->sclass,
4359 4360 4361 4362
						   SOCKET__NAME_BIND, &ad);
				if (err)
					goto out;
			}
L
Linus Torvalds 已提交
4363
		}
4364

4365
		switch (sksec->sclass) {
4366
		case SECCLASS_TCP_SOCKET:
L
Linus Torvalds 已提交
4367 4368
			node_perm = TCP_SOCKET__NODE_BIND;
			break;
4369

4370
		case SECCLASS_UDP_SOCKET:
L
Linus Torvalds 已提交
4371 4372
			node_perm = UDP_SOCKET__NODE_BIND;
			break;
J
James Morris 已提交
4373 4374 4375 4376 4377

		case SECCLASS_DCCP_SOCKET:
			node_perm = DCCP_SOCKET__NODE_BIND;
			break;

L
Linus Torvalds 已提交
4378 4379 4380 4381
		default:
			node_perm = RAWIP_SOCKET__NODE_BIND;
			break;
		}
4382

4383
		err = sel_netnode_sid(addrp, family, &sid);
L
Linus Torvalds 已提交
4384 4385
		if (err)
			goto out;
4386

4387
		ad.type = LSM_AUDIT_DATA_NET;
4388 4389 4390
		ad.u.net = &net;
		ad.u.net->sport = htons(snum);
		ad.u.net->family = family;
L
Linus Torvalds 已提交
4391 4392

		if (family == PF_INET)
4393
			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
L
Linus Torvalds 已提交
4394
		else
4395
			ad.u.net->v6info.saddr = addr6->sin6_addr;
L
Linus Torvalds 已提交
4396

4397 4398
		err = avc_has_perm(sksec->sid, sid,
				   sksec->sclass, node_perm, &ad);
L
Linus Torvalds 已提交
4399 4400 4401 4402 4403 4404 4405 4406 4407
		if (err)
			goto out;
	}
out:
	return err;
}

static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
{
4408
	struct sock *sk = sock->sk;
4409
	struct sk_security_struct *sksec = sk->sk_security;
L
Linus Torvalds 已提交
4410 4411
	int err;

4412
	err = sock_has_perm(current, sk, SOCKET__CONNECT);
L
Linus Torvalds 已提交
4413 4414 4415 4416
	if (err)
		return err;

	/*
J
James Morris 已提交
4417
	 * If a TCP or DCCP socket, check name_connect permission for the port.
L
Linus Torvalds 已提交
4418
	 */
4419 4420
	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
4421
		struct common_audit_data ad;
4422
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4423 4424 4425
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
J
James Morris 已提交
4426
		u32 sid, perm;
L
Linus Torvalds 已提交
4427 4428 4429

		if (sk->sk_family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
4430
			if (addrlen < sizeof(struct sockaddr_in))
L
Linus Torvalds 已提交
4431 4432 4433 4434
				return -EINVAL;
			snum = ntohs(addr4->sin_port);
		} else {
			addr6 = (struct sockaddr_in6 *)address;
4435
			if (addrlen < SIN6_LEN_RFC2133)
L
Linus Torvalds 已提交
4436 4437 4438 4439
				return -EINVAL;
			snum = ntohs(addr6->sin6_port);
		}

P
Paul Moore 已提交
4440
		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
L
Linus Torvalds 已提交
4441 4442 4443
		if (err)
			goto out;

4444
		perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
J
James Morris 已提交
4445 4446
		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;

4447
		ad.type = LSM_AUDIT_DATA_NET;
4448 4449 4450
		ad.u.net = &net;
		ad.u.net->dport = htons(snum);
		ad.u.net->family = sk->sk_family;
4451
		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
L
Linus Torvalds 已提交
4452 4453 4454 4455
		if (err)
			goto out;
	}

4456 4457
	err = selinux_netlbl_socket_connect(sk, address);

L
Linus Torvalds 已提交
4458 4459 4460 4461 4462 4463
out:
	return err;
}

static int selinux_socket_listen(struct socket *sock, int backlog)
{
4464
	return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
L
Linus Torvalds 已提交
4465 4466 4467 4468 4469 4470 4471 4472
}

static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
{
	int err;
	struct inode_security_struct *isec;
	struct inode_security_struct *newisec;

4473
	err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
L
Linus Torvalds 已提交
4474 4475 4476
	if (err)
		return err;

4477
	newisec = inode_security_novalidate(SOCK_INODE(newsock));
L
Linus Torvalds 已提交
4478

4479
	isec = inode_security_novalidate(SOCK_INODE(sock));
L
Linus Torvalds 已提交
4480 4481
	newisec->sclass = isec->sclass;
	newisec->sid = isec->sid;
4482
	newisec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
4483 4484 4485 4486 4487

	return 0;
}

static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4488
				  int size)
L
Linus Torvalds 已提交
4489
{
4490
	return sock_has_perm(current, sock->sk, SOCKET__WRITE);
L
Linus Torvalds 已提交
4491 4492 4493 4494 4495
}

static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
				  int size, int flags)
{
4496
	return sock_has_perm(current, sock->sk, SOCKET__READ);
L
Linus Torvalds 已提交
4497 4498 4499 4500
}

static int selinux_socket_getsockname(struct socket *sock)
{
4501
	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4502 4503 4504 4505
}

static int selinux_socket_getpeername(struct socket *sock)
{
4506
	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4507 4508
}

4509
static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
L
Linus Torvalds 已提交
4510
{
4511 4512
	int err;

4513
	err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4514 4515 4516 4517
	if (err)
		return err;

	return selinux_netlbl_socket_setsockopt(sock, level, optname);
L
Linus Torvalds 已提交
4518 4519 4520 4521 4522
}

static int selinux_socket_getsockopt(struct socket *sock, int level,
				     int optname)
{
4523
	return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
L
Linus Torvalds 已提交
4524 4525 4526 4527
}

static int selinux_socket_shutdown(struct socket *sock, int how)
{
4528
	return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
L
Linus Torvalds 已提交
4529 4530
}

4531 4532
static int selinux_socket_unix_stream_connect(struct sock *sock,
					      struct sock *other,
L
Linus Torvalds 已提交
4533 4534
					      struct sock *newsk)
{
4535 4536
	struct sk_security_struct *sksec_sock = sock->sk_security;
	struct sk_security_struct *sksec_other = other->sk_security;
4537
	struct sk_security_struct *sksec_new = newsk->sk_security;
4538
	struct common_audit_data ad;
4539
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4540 4541
	int err;

4542
	ad.type = LSM_AUDIT_DATA_NET;
4543 4544
	ad.u.net = &net;
	ad.u.net->sk = other;
L
Linus Torvalds 已提交
4545

4546 4547
	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
			   sksec_other->sclass,
L
Linus Torvalds 已提交
4548 4549 4550 4551 4552
			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
	if (err)
		return err;

	/* server child socket */
4553 4554 4555 4556 4557
	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;
4558

4559 4560 4561 4562
	/* connecting socket */
	sksec_sock->peer_sid = sksec_new->sid;

	return 0;
L
Linus Torvalds 已提交
4563 4564 4565 4566 4567
}

static int selinux_socket_unix_may_send(struct socket *sock,
					struct socket *other)
{
4568 4569
	struct sk_security_struct *ssec = sock->sk->sk_security;
	struct sk_security_struct *osec = other->sk->sk_security;
4570
	struct common_audit_data ad;
4571
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4572

4573
	ad.type = LSM_AUDIT_DATA_NET;
4574 4575
	ad.u.net = &net;
	ad.u.net->sk = other->sk;
L
Linus Torvalds 已提交
4576

4577 4578
	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
			    &ad);
L
Linus Torvalds 已提交
4579 4580
}

4581 4582
static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
				    char *addrp, u16 family, u32 peer_sid,
4583
				    struct common_audit_data *ad)
4584 4585 4586 4587 4588
{
	int err;
	u32 if_sid;
	u32 node_sid;

4589
	err = sel_netif_sid(ns, ifindex, &if_sid);
4590 4591 4592 4593 4594 4595 4596 4597 4598 4599 4600 4601 4602 4603
	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);
}

4604
static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4605
				       u16 family)
4606
{
4607
	int err = 0;
4608 4609
	struct sk_security_struct *sksec = sk->sk_security;
	u32 sk_sid = sksec->sid;
4610
	struct common_audit_data ad;
4611
	struct lsm_network_audit net = {0,};
4612 4613
	char *addrp;

4614
	ad.type = LSM_AUDIT_DATA_NET;
4615 4616 4617
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4618 4619 4620
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
	if (err)
		return err;
L
Linus Torvalds 已提交
4621

4622
	if (selinux_secmark_enabled()) {
4623
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4624
				   PACKET__RECV, &ad);
4625 4626 4627
		if (err)
			return err;
	}
4628

4629 4630 4631 4632
	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
	if (err)
		return err;
	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4633

4634 4635 4636 4637 4638
	return err;
}

static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
4639
	int err;
4640
	struct sk_security_struct *sksec = sk->sk_security;
4641 4642
	u16 family = sk->sk_family;
	u32 sk_sid = sksec->sid;
4643
	struct common_audit_data ad;
4644
	struct lsm_network_audit net = {0,};
4645
	char *addrp;
4646 4647
	u8 secmark_active;
	u8 peerlbl_active;
4648 4649

	if (family != PF_INET && family != PF_INET6)
4650
		return 0;
4651 4652

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
A
Al Viro 已提交
4653
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4654 4655
		family = PF_INET;

4656 4657 4658 4659
	/* 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. */
4660
	if (!selinux_policycap_netpeer)
4661 4662 4663
		return selinux_sock_rcv_skb_compat(sk, skb, family);

	secmark_active = selinux_secmark_enabled();
4664
	peerlbl_active = selinux_peerlbl_enabled();
4665 4666 4667
	if (!secmark_active && !peerlbl_active)
		return 0;

4668
	ad.type = LSM_AUDIT_DATA_NET;
4669 4670 4671
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4672
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4673
	if (err)
4674
		return err;
4675

4676
	if (peerlbl_active) {
4677 4678 4679
		u32 peer_sid;

		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4680 4681
		if (err)
			return err;
4682 4683
		err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
					       addrp, family, peer_sid, &ad);
4684
		if (err) {
4685
			selinux_netlbl_err(skb, family, err, 0);
4686
			return err;
4687
		}
4688 4689
		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
				   PEER__RECV, &ad);
C
Chad Hanson 已提交
4690
		if (err) {
4691
			selinux_netlbl_err(skb, family, err, 0);
C
Chad Hanson 已提交
4692 4693
			return err;
		}
4694 4695
	}

4696
	if (secmark_active) {
4697 4698 4699 4700 4701 4702
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
				   PACKET__RECV, &ad);
		if (err)
			return err;
	}

4703
	return err;
L
Linus Torvalds 已提交
4704 4705
}

C
Catherine Zhang 已提交
4706 4707
static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
					    int __user *optlen, unsigned len)
L
Linus Torvalds 已提交
4708 4709 4710 4711
{
	int err = 0;
	char *scontext;
	u32 scontext_len;
4712
	struct sk_security_struct *sksec = sock->sk->sk_security;
4713
	u32 peer_sid = SECSID_NULL;
L
Linus Torvalds 已提交
4714

4715 4716
	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
	    sksec->sclass == SECCLASS_TCP_SOCKET)
4717
		peer_sid = sksec->peer_sid;
4718 4719
	if (peer_sid == SECSID_NULL)
		return -ENOPROTOOPT;
L
Linus Torvalds 已提交
4720

C
Catherine Zhang 已提交
4721
	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
L
Linus Torvalds 已提交
4722
	if (err)
4723
		return err;
L
Linus Torvalds 已提交
4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739

	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;
}

4740
static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
C
Catherine Zhang 已提交
4741
{
4742
	u32 peer_secid = SECSID_NULL;
4743
	u16 family;
4744
	struct inode_security_struct *isec;
C
Catherine Zhang 已提交
4745

4746 4747 4748 4749 4750
	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)
4751 4752 4753 4754
		family = sock->sk->sk_family;
	else
		goto out;

4755 4756 4757 4758
	if (sock && family == PF_UNIX) {
		isec = inode_security_novalidate(SOCK_INODE(sock));
		peer_secid = isec->sid;
	} else if (skb)
4759
		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
C
Catherine Zhang 已提交
4760

4761
out:
4762
	*secid = peer_secid;
4763 4764 4765
	if (peer_secid == SECSID_NULL)
		return -EINVAL;
	return 0;
C
Catherine Zhang 已提交
4766 4767
}

A
Al Viro 已提交
4768
static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
L
Linus Torvalds 已提交
4769
{
4770 4771 4772 4773 4774 4775 4776 4777
	struct sk_security_struct *sksec;

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

	sksec->peer_sid = SECINITSID_UNLABELED;
	sksec->sid = SECINITSID_UNLABELED;
4778
	sksec->sclass = SECCLASS_SOCKET;
4779 4780 4781 4782
	selinux_netlbl_sk_security_reset(sksec);
	sk->sk_security = sksec;

	return 0;
L
Linus Torvalds 已提交
4783 4784 4785 4786
}

static void selinux_sk_free_security(struct sock *sk)
{
4787 4788 4789 4790 4791
	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
4792 4793
}

4794
static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4795
{
4796 4797
	struct sk_security_struct *sksec = sk->sk_security;
	struct sk_security_struct *newsksec = newsk->sk_security;
4798

4799 4800 4801
	newsksec->sid = sksec->sid;
	newsksec->peer_sid = sksec->peer_sid;
	newsksec->sclass = sksec->sclass;
4802

4803
	selinux_netlbl_sk_security_reset(newsksec);
4804 4805
}

V
Venkat Yekkirala 已提交
4806
static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4807
{
4808
	if (!sk)
V
Venkat Yekkirala 已提交
4809
		*secid = SECINITSID_ANY_SOCKET;
4810 4811
	else {
		struct sk_security_struct *sksec = sk->sk_security;
4812

V
Venkat Yekkirala 已提交
4813
		*secid = sksec->sid;
4814
	}
4815 4816
}

4817
static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4818
{
4819 4820
	struct inode_security_struct *isec =
		inode_security_novalidate(SOCK_INODE(parent));
4821 4822
	struct sk_security_struct *sksec = sk->sk_security;

4823 4824
	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
	    sk->sk_family == PF_UNIX)
4825
		isec->sid = sksec->sid;
4826
	sksec->sclass = isec->sclass;
4827 4828
}

4829 4830
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				     struct request_sock *req)
4831 4832 4833
{
	struct sk_security_struct *sksec = sk->sk_security;
	int err;
4834
	u16 family = req->rsk_ops->family;
4835
	u32 connsid;
4836 4837
	u32 peersid;

4838
	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4839 4840
	if (err)
		return err;
4841 4842 4843 4844 4845
	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
	if (err)
		return err;
	req->secid = connsid;
	req->peer_secid = peersid;
4846

4847
	return selinux_netlbl_inet_conn_request(req, family);
4848 4849
}

4850 4851
static void selinux_inet_csk_clone(struct sock *newsk,
				   const struct request_sock *req)
4852 4853 4854 4855
{
	struct sk_security_struct *newsksec = newsk->sk_security;

	newsksec->sid = req->secid;
4856
	newsksec->peer_sid = req->peer_secid;
4857 4858 4859 4860
	/* 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. */
4861

P
Paul Moore 已提交
4862 4863
	/* We don't need to take any sort of lock here as we are the only
	 * thread with access to newsksec */
4864
	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4865 4866
}

4867
static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4868
{
4869
	u16 family = sk->sk_family;
4870 4871
	struct sk_security_struct *sksec = sk->sk_security;

4872 4873 4874 4875 4876
	/* 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);
4877 4878
}

4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898 4899
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);
}

4900 4901
static void selinux_req_classify_flow(const struct request_sock *req,
				      struct flowi *fl)
4902
{
4903
	fl->flowi_secid = req->secid;
4904 4905
}

4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923
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);
}

4924 4925 4926 4927 4928 4929 4930 4931 4932 4933 4934 4935 4936 4937 4938
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);
}

4939
static int selinux_tun_dev_attach_queue(void *security)
4940
{
4941 4942 4943 4944 4945 4946 4947 4948 4949
	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;
4950 4951 4952 4953 4954 4955 4956 4957 4958
	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 */

4959
	sksec->sid = tunsec->sid;
4960
	sksec->sclass = SECCLASS_TUN_SOCKET;
4961 4962

	return 0;
4963 4964
}

4965
static int selinux_tun_dev_open(void *security)
4966
{
4967
	struct tun_security_struct *tunsec = security;
4968 4969 4970
	u32 sid = current_sid();
	int err;

4971
	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
4972 4973 4974 4975 4976 4977 4978
			   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;
4979
	tunsec->sid = sid;
4980 4981 4982 4983

	return 0;
}

L
Linus Torvalds 已提交
4984 4985 4986 4987 4988
static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
{
	int err = 0;
	u32 perm;
	struct nlmsghdr *nlh;
4989
	struct sk_security_struct *sksec = sk->sk_security;
4990

4991
	if (skb->len < NLMSG_HDRLEN) {
L
Linus Torvalds 已提交
4992 4993 4994
		err = -EINVAL;
		goto out;
	}
4995
	nlh = nlmsg_hdr(skb);
4996

4997
	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
L
Linus Torvalds 已提交
4998 4999
	if (err) {
		if (err == -EINVAL) {
5000 5001 5002
			pr_warn_ratelimited("SELinux: unrecognized netlink"
			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
			       " pig=%d comm=%s\n",
5003
			       sk->sk_protocol, nlh->nlmsg_type,
5004 5005
			       secclass_map[sksec->sclass - 1].name,
			       task_pid_nr(current), current->comm);
5006
			if (!selinux_enforcing || security_get_allow_unknown())
L
Linus Torvalds 已提交
5007 5008 5009 5010 5011 5012 5013 5014 5015
				err = 0;
		}

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

5016
	err = sock_has_perm(current, sk, perm);
L
Linus Torvalds 已提交
5017 5018 5019 5020 5021 5022
out:
	return err;
}

#ifdef CONFIG_NETFILTER

5023 5024
static unsigned int selinux_ip_forward(struct sk_buff *skb,
				       const struct net_device *indev,
5025
				       u16 family)
L
Linus Torvalds 已提交
5026
{
5027
	int err;
5028 5029
	char *addrp;
	u32 peer_sid;
5030
	struct common_audit_data ad;
5031
	struct lsm_network_audit net = {0,};
5032
	u8 secmark_active;
5033
	u8 netlbl_active;
5034
	u8 peerlbl_active;
5035

5036 5037
	if (!selinux_policycap_netpeer)
		return NF_ACCEPT;
5038

5039
	secmark_active = selinux_secmark_enabled();
5040
	netlbl_active = netlbl_enabled();
5041
	peerlbl_active = selinux_peerlbl_enabled();
5042 5043
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;
5044

5045 5046 5047
	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
		return NF_DROP;

5048
	ad.type = LSM_AUDIT_DATA_NET;
5049
	ad.u.net = &net;
5050
	ad.u.net->netif = indev->ifindex;
5051
	ad.u.net->family = family;
5052 5053 5054
	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
		return NF_DROP;

5055
	if (peerlbl_active) {
5056 5057
		err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
					       addrp, family, peer_sid, &ad);
5058
		if (err) {
5059
			selinux_netlbl_err(skb, family, err, 1);
5060
			return NF_DROP;
5061 5062
		}
	}
5063 5064 5065 5066 5067 5068

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

5069 5070 5071 5072 5073 5074 5075 5076
	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;

5077 5078 5079
	return NF_ACCEPT;
}

5080
static unsigned int selinux_ipv4_forward(void *priv,
5081
					 struct sk_buff *skb,
5082
					 const struct nf_hook_state *state)
5083
{
5084
	return selinux_ip_forward(skb, state->in, PF_INET);
5085 5086
}

5087
#if IS_ENABLED(CONFIG_IPV6)
5088
static unsigned int selinux_ipv6_forward(void *priv,
5089
					 struct sk_buff *skb,
5090
					 const struct nf_hook_state *state)
5091
{
5092
	return selinux_ip_forward(skb, state->in, PF_INET6);
5093 5094 5095
}
#endif	/* IPV6 */

5096 5097 5098
static unsigned int selinux_ip_output(struct sk_buff *skb,
				      u16 family)
{
5099
	struct sock *sk;
5100 5101 5102 5103 5104 5105 5106 5107
	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 */
5108 5109 5110 5111
	sk = skb->sk;
	if (sk) {
		struct sk_security_struct *sksec;

5112
		if (sk_listener(sk))
5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128
			/* 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;
5129 5130 5131 5132 5133 5134 5135 5136 5137
		sid = sksec->sid;
	} else
		sid = SECINITSID_KERNEL;
	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
		return NF_DROP;

	return NF_ACCEPT;
}

5138
static unsigned int selinux_ipv4_output(void *priv,
5139
					struct sk_buff *skb,
5140
					const struct nf_hook_state *state)
5141 5142 5143 5144
{
	return selinux_ip_output(skb, PF_INET);
}

5145
#if IS_ENABLED(CONFIG_IPV6)
5146 5147 5148 5149 5150 5151 5152 5153
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 */

5154 5155
static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
						int ifindex,
5156
						u16 family)
5157
{
5158
	struct sock *sk = skb_to_full_sk(skb);
5159
	struct sk_security_struct *sksec;
5160
	struct common_audit_data ad;
5161
	struct lsm_network_audit net = {0,};
5162 5163
	char *addrp;
	u8 proto;
L
Linus Torvalds 已提交
5164

5165 5166 5167 5168
	if (sk == NULL)
		return NF_ACCEPT;
	sksec = sk->sk_security;

5169
	ad.type = LSM_AUDIT_DATA_NET;
5170 5171 5172
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
5173 5174 5175
	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
		return NF_DROP;

5176
	if (selinux_secmark_enabled())
5177
		if (avc_has_perm(sksec->sid, skb->secmark,
5178
				 SECCLASS_PACKET, PACKET__SEND, &ad))
5179
			return NF_DROP_ERR(-ECONNREFUSED);
5180

5181 5182
	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
		return NF_DROP_ERR(-ECONNREFUSED);
5183 5184

	return NF_ACCEPT;
5185 5186
}

5187 5188
static unsigned int selinux_ip_postroute(struct sk_buff *skb,
					 const struct net_device *outdev,
5189
					 u16 family)
5190
{
5191 5192
	u32 secmark_perm;
	u32 peer_sid;
5193
	int ifindex = outdev->ifindex;
5194
	struct sock *sk;
5195
	struct common_audit_data ad;
5196
	struct lsm_network_audit net = {0,};
5197 5198 5199
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;
5200

5201 5202 5203 5204
	/* 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. */
5205
	if (!selinux_policycap_netpeer)
5206
		return selinux_ip_postroute_compat(skb, ifindex, family);
5207 5208 5209 5210 5211 5212

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

5213
	sk = skb_to_full_sk(skb);
5214

5215
#ifdef CONFIG_XFRM
5216 5217 5218 5219 5220
	/* 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
5221 5222 5223 5224 5225 5226 5227
	 *       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 &&
5228
	    !(sk && sk_listener(sk)))
5229
		return NF_ACCEPT;
5230
#endif
5231

5232
	if (sk == NULL) {
5233 5234 5235 5236
		/* 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. */
5237 5238
		if (skb->skb_iif) {
			secmark_perm = PACKET__FORWARD_OUT;
5239
			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5240
				return NF_DROP;
5241 5242
		} else {
			secmark_perm = PACKET__SEND;
5243
			peer_sid = SECINITSID_KERNEL;
5244
		}
5245
	} else if (sk_listener(sk)) {
5246 5247 5248 5249 5250 5251 5252 5253 5254 5255
		/* 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;
5256 5257 5258
		struct sk_security_struct *sksec;

		sksec = sk->sk_security;
5259 5260
		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
			return NF_DROP;
5261 5262 5263 5264 5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275
		/* 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;
5276
				break;
5277 5278 5279 5280
			default:
				return NF_DROP_ERR(-ECONNREFUSED);
			}
		}
5281 5282 5283
		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
			return NF_DROP;
		secmark_perm = PACKET__SEND;
5284
	} else {
5285 5286
		/* Locally generated packet, fetch the security label from the
		 * associated socket. */
5287 5288 5289 5290
		struct sk_security_struct *sksec = sk->sk_security;
		peer_sid = sksec->sid;
		secmark_perm = PACKET__SEND;
	}
5291

5292
	ad.type = LSM_AUDIT_DATA_NET;
5293 5294 5295
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
5296
	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5297
		return NF_DROP;
5298

5299 5300 5301
	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, secmark_perm, &ad))
5302
			return NF_DROP_ERR(-ECONNREFUSED);
5303 5304 5305 5306 5307

	if (peerlbl_active) {
		u32 if_sid;
		u32 node_sid;

5308
		if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
5309
			return NF_DROP;
5310 5311
		if (avc_has_perm(peer_sid, if_sid,
				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5312
			return NF_DROP_ERR(-ECONNREFUSED);
5313 5314

		if (sel_netnode_sid(addrp, family, &node_sid))
5315
			return NF_DROP;
5316 5317
		if (avc_has_perm(peer_sid, node_sid,
				 SECCLASS_NODE, NODE__SENDTO, &ad))
5318
			return NF_DROP_ERR(-ECONNREFUSED);
5319
	}
5320

5321
	return NF_ACCEPT;
L
Linus Torvalds 已提交
5322 5323
}

5324
static unsigned int selinux_ipv4_postroute(void *priv,
5325
					   struct sk_buff *skb,
5326
					   const struct nf_hook_state *state)
L
Linus Torvalds 已提交
5327
{
5328
	return selinux_ip_postroute(skb, state->out, PF_INET);
L
Linus Torvalds 已提交
5329 5330
}

5331
#if IS_ENABLED(CONFIG_IPV6)
5332
static unsigned int selinux_ipv6_postroute(void *priv,
5333
					   struct sk_buff *skb,
5334
					   const struct nf_hook_state *state)
L
Linus Torvalds 已提交
5335
{
5336
	return selinux_ip_postroute(skb, state->out, PF_INET6);
L
Linus Torvalds 已提交
5337 5338 5339 5340 5341 5342 5343
}
#endif	/* IPV6 */

#endif	/* CONFIG_NETFILTER */

static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
{
5344
	return selinux_nlmsg_perm(sk, skb);
L
Linus Torvalds 已提交
5345 5346 5347 5348 5349 5350 5351
}

static int ipc_alloc_security(struct task_struct *task,
			      struct kern_ipc_perm *perm,
			      u16 sclass)
{
	struct ipc_security_struct *isec;
5352
	u32 sid;
L
Linus Torvalds 已提交
5353

J
James Morris 已提交
5354
	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
5355 5356 5357
	if (!isec)
		return -ENOMEM;

5358
	sid = task_sid(task);
L
Linus Torvalds 已提交
5359
	isec->sclass = sclass;
5360
	isec->sid = sid;
L
Linus Torvalds 已提交
5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376
	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
5377
	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
5378 5379 5380 5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395
	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,
5396
			u32 perms)
L
Linus Torvalds 已提交
5397 5398
{
	struct ipc_security_struct *isec;
5399
	struct common_audit_data ad;
5400
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5401 5402 5403

	isec = ipc_perms->security;

5404
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5405 5406
	ad.u.ipc_id = ipc_perms->key;

5407
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
L
Linus Torvalds 已提交
5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 5419 5420 5421 5422 5423
}

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;
5424
	struct common_audit_data ad;
5425
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5426 5427 5428 5429 5430 5431 5432 5433
	int rc;

	rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
	if (rc)
		return rc;

	isec = msq->q_perm.security;

5434
	ad.type = LSM_AUDIT_DATA_IPC;
5435
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5436

5437
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453
			  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;
5454
	struct common_audit_data ad;
5455
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5456 5457 5458

	isec = msq->q_perm.security;

5459
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5460 5461
	ad.u.ipc_id = msq->q_perm.key;

5462
	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5463 5464 5465 5466 5467 5468 5469 5470
			    MSGQ__ASSOCIATE, &ad);
}

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

5471
	switch (cmd) {
L
Linus Torvalds 已提交
5472 5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489
	case IPC_INFO:
	case MSG_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	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;
	}

5490
	err = ipc_has_perm(&msq->q_perm, perms);
L
Linus Torvalds 已提交
5491 5492 5493 5494 5495 5496 5497
	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;
5498
	struct common_audit_data ad;
5499
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5500 5501 5502 5503 5504 5505 5506 5507 5508 5509 5510 5511 5512
	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
		 */
5513
		rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5514
					     NULL, &msec->sid);
L
Linus Torvalds 已提交
5515 5516 5517 5518
		if (rc)
			return rc;
	}

5519
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5520 5521 5522
	ad.u.ipc_id = msq->q_perm.key;

	/* Can this process write to the queue? */
5523
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5524 5525 5526
			  MSGQ__WRITE, &ad);
	if (!rc)
		/* Can this process send the message */
5527 5528
		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
				  MSG__SEND, &ad);
L
Linus Torvalds 已提交
5529 5530
	if (!rc)
		/* Can the message be put in the queue? */
5531 5532
		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
				  MSGQ__ENQUEUE, &ad);
L
Linus Torvalds 已提交
5533 5534 5535 5536 5537 5538 5539 5540 5541 5542

	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;
5543
	struct common_audit_data ad;
5544
	u32 sid = task_sid(target);
L
Linus Torvalds 已提交
5545 5546 5547 5548 5549
	int rc;

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

5550
	ad.type = LSM_AUDIT_DATA_IPC;
5551
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5552

5553
	rc = avc_has_perm(sid, isec->sid,
L
Linus Torvalds 已提交
5554 5555
			  SECCLASS_MSGQ, MSGQ__READ, &ad);
	if (!rc)
5556
		rc = avc_has_perm(sid, msec->sid,
L
Linus Torvalds 已提交
5557 5558 5559 5560 5561 5562 5563 5564
				  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;
5565
	struct common_audit_data ad;
5566
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5567 5568 5569 5570 5571 5572 5573 5574
	int rc;

	rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
	if (rc)
		return rc;

	isec = shp->shm_perm.security;

5575
	ad.type = LSM_AUDIT_DATA_IPC;
5576
	ad.u.ipc_id = shp->shm_perm.key;
L
Linus Torvalds 已提交
5577

5578
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5579 5580 5581 5582 5583 5584 5585 5586 5587 5588 5589 5590 5591 5592 5593 5594
			  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;
5595
	struct common_audit_data ad;
5596
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5597 5598 5599

	isec = shp->shm_perm.security;

5600
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5601 5602
	ad.u.ipc_id = shp->shm_perm.key;

5603
	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5604 5605 5606 5607 5608 5609 5610 5611 5612
			    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;

5613
	switch (cmd) {
L
Linus Torvalds 已提交
5614 5615 5616 5617 5618 5619 5620 5621 5622 5623 5624 5625 5626 5627 5628 5629 5630 5631 5632 5633 5634 5635
	case IPC_INFO:
	case SHM_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	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;
	}

5636
	err = ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649
	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;

5650
	return ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5651 5652 5653 5654 5655 5656
}

/* Semaphore security operations */
static int selinux_sem_alloc_security(struct sem_array *sma)
{
	struct ipc_security_struct *isec;
5657
	struct common_audit_data ad;
5658
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5659 5660 5661 5662 5663 5664 5665 5666
	int rc;

	rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
	if (rc)
		return rc;

	isec = sma->sem_perm.security;

5667
	ad.type = LSM_AUDIT_DATA_IPC;
5668
	ad.u.ipc_id = sma->sem_perm.key;
L
Linus Torvalds 已提交
5669

5670
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5671 5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 5683 5684 5685 5686
			  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;
5687
	struct common_audit_data ad;
5688
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5689 5690 5691

	isec = sma->sem_perm.security;

5692
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5693 5694
	ad.u.ipc_id = sma->sem_perm.key;

5695
	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5696 5697 5698 5699 5700 5701 5702 5703 5704
			    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;

5705
	switch (cmd) {
L
Linus Torvalds 已提交
5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724 5725 5726 5727 5728 5729 5730 5731 5732 5733 5734 5735 5736
	case IPC_INFO:
	case SEM_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	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;
	}

5737
	err = ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750
	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;

5751
	return ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766
}

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;

5767
	return ipc_has_perm(ipcp, av);
L
Linus Torvalds 已提交
5768 5769
}

5770 5771 5772 5773 5774 5775
static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
{
	struct ipc_security_struct *isec = ipcp->security;
	*secid = isec->sid;
}

5776
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
L
Linus Torvalds 已提交
5777 5778 5779 5780 5781 5782
{
	if (inode)
		inode_doinit_with_dentry(inode, dentry);
}

static int selinux_getprocattr(struct task_struct *p,
5783
			       char *name, char **value)
L
Linus Torvalds 已提交
5784
{
5785
	const struct task_security_struct *__tsec;
5786
	u32 sid;
L
Linus Torvalds 已提交
5787
	int error;
5788
	unsigned len;
L
Linus Torvalds 已提交
5789 5790

	if (current != p) {
5791
		error = current_has_perm(p, PROCESS__GETATTR);
L
Linus Torvalds 已提交
5792 5793 5794 5795
		if (error)
			return error;
	}

5796 5797
	rcu_read_lock();
	__tsec = __task_cred(p)->security;
L
Linus Torvalds 已提交
5798 5799

	if (!strcmp(name, "current"))
5800
		sid = __tsec->sid;
L
Linus Torvalds 已提交
5801
	else if (!strcmp(name, "prev"))
5802
		sid = __tsec->osid;
L
Linus Torvalds 已提交
5803
	else if (!strcmp(name, "exec"))
5804
		sid = __tsec->exec_sid;
L
Linus Torvalds 已提交
5805
	else if (!strcmp(name, "fscreate"))
5806
		sid = __tsec->create_sid;
5807
	else if (!strcmp(name, "keycreate"))
5808
		sid = __tsec->keycreate_sid;
5809
	else if (!strcmp(name, "sockcreate"))
5810
		sid = __tsec->sockcreate_sid;
L
Linus Torvalds 已提交
5811
	else
5812 5813
		goto invalid;
	rcu_read_unlock();
L
Linus Torvalds 已提交
5814 5815 5816 5817

	if (!sid)
		return 0;

5818 5819 5820 5821
	error = security_sid_to_context(sid, value, &len);
	if (error)
		return error;
	return len;
5822 5823 5824 5825

invalid:
	rcu_read_unlock();
	return -EINVAL;
L
Linus Torvalds 已提交
5826 5827 5828 5829 5830 5831
}

static int selinux_setprocattr(struct task_struct *p,
			       char *name, void *value, size_t size)
{
	struct task_security_struct *tsec;
D
David Howells 已提交
5832 5833
	struct cred *new;
	u32 sid = 0, ptsid;
L
Linus Torvalds 已提交
5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848
	int error;
	char *str = value;

	if (current != p) {
		/* SELinux only allows a process to change its own
		   security attributes. */
		return -EACCES;
	}

	/*
	 * Basic control over ability to set these attributes at all.
	 * current == p, but we'll pass them separately in case the
	 * above restriction is ever removed.
	 */
	if (!strcmp(name, "exec"))
5849
		error = current_has_perm(p, PROCESS__SETEXEC);
L
Linus Torvalds 已提交
5850
	else if (!strcmp(name, "fscreate"))
5851
		error = current_has_perm(p, PROCESS__SETFSCREATE);
5852
	else if (!strcmp(name, "keycreate"))
5853
		error = current_has_perm(p, PROCESS__SETKEYCREATE);
5854
	else if (!strcmp(name, "sockcreate"))
5855
		error = current_has_perm(p, PROCESS__SETSOCKCREATE);
L
Linus Torvalds 已提交
5856
	else if (!strcmp(name, "current"))
5857
		error = current_has_perm(p, PROCESS__SETCURRENT);
L
Linus Torvalds 已提交
5858 5859 5860 5861 5862 5863 5864 5865 5866 5867 5868
	else
		error = -EINVAL;
	if (error)
		return error;

	/* Obtain a SID for the context, if one was specified. */
	if (size && str[1] && str[1] != '\n') {
		if (str[size-1] == '\n') {
			str[size-1] = 0;
			size--;
		}
5869
		error = security_context_to_sid(value, size, &sid, GFP_KERNEL);
5870
		if (error == -EINVAL && !strcmp(name, "fscreate")) {
5871 5872 5873 5874 5875 5876 5877 5878 5879 5880 5881 5882 5883 5884 5885
			if (!capable(CAP_MAC_ADMIN)) {
				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);

5886
				return error;
5887
			}
5888 5889 5890
			error = security_context_to_sid_force(value, size,
							      &sid);
		}
L
Linus Torvalds 已提交
5891 5892 5893 5894
		if (error)
			return error;
	}

D
David Howells 已提交
5895 5896 5897 5898
	new = prepare_creds();
	if (!new)
		return -ENOMEM;

L
Linus Torvalds 已提交
5899 5900 5901
	/* 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
5902
	   operation.  See selinux_bprm_set_creds for the execve
L
Linus Torvalds 已提交
5903 5904
	   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
5905 5906
	tsec = new->security;
	if (!strcmp(name, "exec")) {
L
Linus Torvalds 已提交
5907
		tsec->exec_sid = sid;
D
David Howells 已提交
5908
	} else if (!strcmp(name, "fscreate")) {
L
Linus Torvalds 已提交
5909
		tsec->create_sid = sid;
D
David Howells 已提交
5910
	} else if (!strcmp(name, "keycreate")) {
5911 5912
		error = may_create_key(sid, p);
		if (error)
D
David Howells 已提交
5913
			goto abort_change;
5914
		tsec->keycreate_sid = sid;
D
David Howells 已提交
5915
	} else if (!strcmp(name, "sockcreate")) {
5916
		tsec->sockcreate_sid = sid;
D
David Howells 已提交
5917 5918
	} else if (!strcmp(name, "current")) {
		error = -EINVAL;
L
Linus Torvalds 已提交
5919
		if (sid == 0)
D
David Howells 已提交
5920 5921 5922 5923
			goto abort_change;

		/* Only allow single threaded processes to change context */
		error = -EPERM;
5924
		if (!current_is_single_threaded()) {
D
David Howells 已提交
5925 5926 5927
			error = security_bounded_transition(tsec->sid, sid);
			if (error)
				goto abort_change;
5928
		}
L
Linus Torvalds 已提交
5929 5930 5931

		/* Check permissions for the transition. */
		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5932
				     PROCESS__DYNTRANSITION, NULL);
L
Linus Torvalds 已提交
5933
		if (error)
D
David Howells 已提交
5934
			goto abort_change;
L
Linus Torvalds 已提交
5935 5936 5937

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and fail. */
5938 5939
		ptsid = ptrace_parent_sid(p);
		if (ptsid != 0) {
D
David Howells 已提交
5940 5941
			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
					     PROCESS__PTRACE, NULL);
L
Linus Torvalds 已提交
5942
			if (error)
D
David Howells 已提交
5943
				goto abort_change;
L
Linus Torvalds 已提交
5944 5945
		}

D
David Howells 已提交
5946 5947 5948 5949 5950 5951 5952
		tsec->sid = sid;
	} else {
		error = -EINVAL;
		goto abort_change;
	}

	commit_creds(new);
L
Linus Torvalds 已提交
5953
	return size;
D
David Howells 已提交
5954 5955 5956 5957

abort_change:
	abort_creds(new);
	return error;
L
Linus Torvalds 已提交
5958 5959
}

5960 5961 5962 5963 5964
static int selinux_ismaclabel(const char *name)
{
	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
}

5965 5966 5967 5968 5969
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
	return security_sid_to_context(secid, secdata, seclen);
}

5970
static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5971
{
5972
	return security_context_to_sid(secdata, seclen, secid, GFP_KERNEL);
5973 5974
}

5975 5976
static void selinux_release_secctx(char *secdata, u32 seclen)
{
5977
	kfree(secdata);
5978 5979
}

5980 5981 5982 5983 5984 5985 5986 5987 5988
static void selinux_inode_invalidate_secctx(struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;

	mutex_lock(&isec->lock);
	isec->initialized = LABEL_INVALID;
	mutex_unlock(&isec->lock);
}

5989 5990 5991 5992 5993 5994 5995 5996 5997 5998 5999 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6011 6012 6013 6014
/*
 *	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;
}
6015 6016
#ifdef CONFIG_KEYS

D
David Howells 已提交
6017
static int selinux_key_alloc(struct key *k, const struct cred *cred,
6018
			     unsigned long flags)
6019
{
D
David Howells 已提交
6020
	const struct task_security_struct *tsec;
6021 6022 6023 6024 6025 6026
	struct key_security_struct *ksec;

	ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
	if (!ksec)
		return -ENOMEM;

D
David Howells 已提交
6027 6028 6029
	tsec = cred->security;
	if (tsec->keycreate_sid)
		ksec->sid = tsec->keycreate_sid;
6030
	else
D
David Howells 已提交
6031
		ksec->sid = tsec->sid;
6032

6033
	k->security = ksec;
6034 6035 6036 6037 6038 6039 6040 6041 6042 6043 6044 6045
	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
6046
				  const struct cred *cred,
6047
				  unsigned perm)
6048 6049 6050
{
	struct key *key;
	struct key_security_struct *ksec;
6051
	u32 sid;
6052 6053 6054 6055 6056 6057 6058

	/* 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
6059
	sid = cred_sid(cred);
6060 6061 6062 6063 6064

	key = key_ref_to_ptr(key_ref);
	ksec = key->security;

	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6065 6066
}

6067 6068 6069 6070 6071 6072 6073 6074 6075 6076 6077 6078 6079 6080
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;
}

6081 6082
#endif

C
Casey Schaufler 已提交
6083
static struct security_hook_list selinux_hooks[] = {
6084 6085 6086 6087 6088 6089 6090 6091 6092 6093 6094 6095 6096 6097 6098 6099 6100 6101 6102 6103 6104 6105 6106 6107 6108 6109 6110 6111 6112 6113 6114 6115 6116 6117 6118 6119
	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(bprm_secureexec, selinux_bprm_secureexec),

	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),
6120
	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
6121 6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132 6133 6134 6135 6136 6137 6138 6139 6140 6141 6142 6143 6144 6145 6146

	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),
6147
	LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
6148
	LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
6149 6150 6151 6152 6153 6154 6155 6156 6157 6158 6159 6160 6161 6162 6163 6164 6165 6166 6167 6168 6169 6170 6171 6172

	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),

	LSM_HOOK_INIT(task_create, selinux_task_create),
	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),
6173
	LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
6174 6175 6176 6177 6178 6179 6180 6181 6182 6183 6184 6185 6186 6187 6188 6189 6190 6191 6192 6193 6194 6195 6196 6197 6198 6199 6200 6201 6202 6203 6204 6205 6206 6207 6208 6209 6210 6211 6212 6213 6214 6215 6216 6217 6218 6219 6220 6221 6222 6223
	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),
	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_wait, selinux_task_wait),
	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),
6224
	LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242 6243 6244 6245 6246 6247 6248 6249 6250 6251 6252 6253 6254 6255 6256 6257 6258 6259 6260 6261 6262 6263 6264 6265 6266
	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),
6267 6268

#ifdef CONFIG_SECURITY_NETWORK_XFRM
6269 6270 6271 6272 6273 6274 6275 6276 6277 6278 6279 6280 6281
	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
6283 6284

#ifdef CONFIG_KEYS
6285 6286 6287 6288
	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),
6289
#endif
6290 6291

#ifdef CONFIG_AUDIT
6292 6293 6294 6295
	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),
6296
#endif
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6297 6298 6299 6300
};

static __init int selinux_init(void)
{
C
Casey Schaufler 已提交
6301
	if (!security_module_enable("selinux")) {
6302 6303 6304 6305
		selinux_enabled = 0;
		return 0;
	}

L
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6306 6307 6308 6309 6310 6311 6312 6313
	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
6314
	cred_init_security();
L
Linus Torvalds 已提交
6315

6316 6317
	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);

6318 6319
	sel_inode_cache = kmem_cache_create("selinux_inode_security",
					    sizeof(struct inode_security_struct),
6320
					    0, SLAB_PANIC, NULL);
6321 6322 6323
	file_security_cache = kmem_cache_create("selinux_file_security",
					    sizeof(struct file_security_struct),
					    0, SLAB_PANIC, NULL);
L
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6324 6325
	avc_init();

C
Casey Schaufler 已提交
6326
	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));
L
Linus Torvalds 已提交
6327

6328 6329 6330
	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
		panic("SELinux: Unable to register AVC netcache callback\n");

6331
	if (selinux_enforcing)
6332
		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
6333
	else
6334
		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
6335

L
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6336 6337 6338
	return 0;
}

6339 6340 6341 6342 6343
static void delayed_superblock_init(struct super_block *sb, void *unused)
{
	superblock_doinit(sb, NULL);
}

L
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6344 6345
void selinux_complete_init(void)
{
6346
	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
L
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6347 6348

	/* Set up any superblocks initialized prior to the policy load. */
6349
	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
6350
	iterate_supers(delayed_superblock_init, NULL);
L
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6351 6352 6353 6354 6355 6356
}

/* SELinux requires early initialization in order to label
   all processes and objects when they are created. */
security_initcall(selinux_init);

6357
#if defined(CONFIG_NETFILTER)
L
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6358

6359
static struct nf_hook_ops selinux_nf_ops[] = {
6360 6361
	{
		.hook =		selinux_ipv4_postroute,
6362
		.pf =		NFPROTO_IPV4,
6363 6364 6365 6366 6367
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv4_forward,
6368
		.pf =		NFPROTO_IPV4,
6369 6370
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
6371 6372 6373
	},
	{
		.hook =		selinux_ipv4_output,
6374
		.pf =		NFPROTO_IPV4,
6375 6376
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
6377
	},
6378
#if IS_ENABLED(CONFIG_IPV6)
6379 6380
	{
		.hook =		selinux_ipv6_postroute,
6381
		.pf =		NFPROTO_IPV6,
6382 6383 6384 6385 6386
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP6_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv6_forward,
6387
		.pf =		NFPROTO_IPV6,
6388 6389
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
6390
	},
6391 6392 6393 6394 6395 6396
	{
		.hook =		selinux_ipv6_output,
		.pf =		NFPROTO_IPV6,
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
	},
L
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6397
#endif	/* IPV6 */
6398
};
L
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6399 6400 6401

static int __init selinux_nf_ip_init(void)
{
6402
	int err;
L
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6403 6404

	if (!selinux_enabled)
6405
		return 0;
6406 6407 6408

	printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");

6409
	err = nf_register_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
6410
	if (err)
6411
		panic("SELinux: nf_register_hooks: error %d\n", err);
L
Linus Torvalds 已提交
6412

6413
	return 0;
L
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6414 6415 6416 6417 6418 6419 6420
}

__initcall(selinux_nf_ip_init);

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static void selinux_nf_ip_exit(void)
{
6421
	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
L
Linus Torvalds 已提交
6422

6423
	nf_unregister_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
L
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6424 6425 6426
}
#endif

6427
#else /* CONFIG_NETFILTER */
L
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6428 6429 6430 6431 6432

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
#define selinux_nf_ip_exit()
#endif

6433
#endif /* CONFIG_NETFILTER */
L
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6434 6435

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
6436 6437
static int selinux_disabled;

L
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6438 6439 6440 6441 6442 6443 6444 6445 6446 6447 6448 6449 6450 6451 6452
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;
6453
	selinux_enabled = 0;
L
Linus Torvalds 已提交
6454

C
Casey Schaufler 已提交
6455
	security_delete_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));
L
Linus Torvalds 已提交
6456

6457 6458 6459
	/* Try to destroy the avc node cache */
	avc_disable();

L
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6460 6461 6462 6463 6464 6465 6466 6467 6468
	/* Unregister netfilter hooks. */
	selinux_nf_ip_exit();

	/* Unregister selinuxfs. */
	exit_sel_fs();

	return 0;
}
#endif