hooks.c 145.1 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>
#include <linux/security.h>
#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/sock.h>
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#include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
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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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#define SB_TYPE_FMT "%s%s%s"
#define SB_SUBTYPE(sb) (sb->s_subtype && sb->s_subtype[0])
#define SB_TYPE_ARGS(sb) sb->s_type->name, SB_SUBTYPE(sb) ? "." : "", SB_SUBTYPE(sb) ? sb->s_subtype : ""

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extern struct security_operations *security_ops;
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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;
	if (!strict_strtoul(str, 0, &enforcing))
		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;
	if (!strict_strtoul(str, 0, &enabled))
		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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/**
 * 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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/*
 * 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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	inode->i_security = isec;

	return 0;
}

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;

	spin_lock(&sbsec->isec_lock);
	if (!list_empty(&isec->list))
		list_del_init(&isec->list);
	spin_unlock(&sbsec->isec_lock);

	inode->i_security = NULL;
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	kmem_cache_free(sel_inode_cache, isec);
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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 = kzalloc(sizeof(struct file_security_struct), 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;
	kfree(fsec);
}

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[6] = {
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	"uses xattr",
	"uses transition SIDs",
	"uses task SIDs",
	"uses genfs_contexts",
	"not configured for labeling",
	"uses mountpoint labeling",
};

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

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;

	if (sbsec->behavior == SECURITY_FS_USE_XATTR ||
	    sbsec->behavior == SECURITY_FS_USE_TRANS ||
	    sbsec->behavior == SECURITY_FS_USE_TASK)
		return 1;

	/* Special handling for sysfs. Is genfs but also has setxattr handler*/
	if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
		return 1;

	/*
	 * Special handling for rootfs. Is genfs but supports
	 * setting SELinux context on in-core inodes.
	 */
	if (strncmp(sb->s_type->name, "rootfs", sizeof("rootfs")) == 0)
		return 1;

	return 0;
}

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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;
	struct inode *root_inode = root->d_inode;
	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. */
		if (!root_inode->i_op->getxattr) {
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			printk(KERN_WARNING "SELinux: (dev %s, type "SB_TYPE_FMT") has no "
			       "xattr support\n", sb->s_id, SB_TYPE_ARGS(sb));
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			rc = -EOPNOTSUPP;
			goto out;
		}
		rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
		if (rc < 0 && rc != -ENODATA) {
			if (rc == -EOPNOTSUPP)
				printk(KERN_WARNING "SELinux: (dev %s, type "
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				       SB_TYPE_FMT") has no security xattr handler\n",
				       sb->s_id, SB_TYPE_ARGS(sb));
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			else
				printk(KERN_WARNING "SELinux: (dev %s, type "
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				       SB_TYPE_FMT") getxattr errno %d\n", sb->s_id,
				       SB_TYPE_ARGS(sb), -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 "SB_TYPE_FMT"), unknown behavior\n",
		       sb->s_id, SB_TYPE_ARGS(sb));
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	else
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		printk(KERN_DEBUG "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), %s\n",
		       sb->s_id, SB_TYPE_ARGS(sb),
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		       labeling_behaviors[sbsec->behavior-1]);
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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;
		spin_unlock(&sbsec->isec_lock);
		inode = igrab(inode);
		if (inode) {
			if (!IS_PRIVATE(inode))
				inode_doinit(inode);
			iput(inode);
		}
		spin_lock(&sbsec->isec_lock);
		list_del_init(&isec->list);
		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)
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{
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	char *context = NULL;
	u32 len;
	char tmp;
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	security_init_mnt_opts(opts);
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	if (!(sbsec->flags & SE_SBINITIALIZED))
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		return -EINVAL;
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	if (!ss_initialized)
		return -EINVAL;
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	/* make sure we always check enough bits to cover the mask */
	BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));

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	tmp = sbsec->flags & SE_MNTMASK;
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	/* count the number of mount options for this sb */
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	for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
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		if (tmp & 0x01)
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			opts->num_mnt_opts++;
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		tmp >>= 1;
	}
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	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts) {
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		rc = -ENOMEM;
		goto out_free;
	}
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	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
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		rc = -ENOMEM;
		goto out_free;
	}
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	i = 0;
	if (sbsec->flags & FSCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->sid, &context, &len);
		if (rc)
			goto out_free;
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		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
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	}
	if (sbsec->flags & CONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
		if (rc)
			goto out_free;
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		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
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	}
	if (sbsec->flags & DEFCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
		if (rc)
			goto out_free;
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		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
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	}
	if (sbsec->flags & ROOTCONTEXT_MNT) {
		struct inode *root = sbsec->sb->s_root->d_inode;
		struct inode_security_struct *isec = root->i_security;
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		rc = security_sid_to_context(isec->sid, &context, &len);
		if (rc)
			goto out_free;
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		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
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	}
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	if (sbsec->flags & SBLABEL_MNT) {
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		opts->mnt_opts[i] = NULL;
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		opts->mnt_opts_flags[i++] = SBLABEL_MNT;
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	}
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	BUG_ON(i != opts->num_mnt_opts);
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	return 0;

out_free:
562
	security_free_mnt_opts(opts);
563 564
	return rc;
}
L
Linus Torvalds 已提交
565

566 567 568
static int bad_option(struct superblock_security_struct *sbsec, char flag,
		      u32 old_sid, u32 new_sid)
{
569 570
	char mnt_flags = sbsec->flags & SE_MNTMASK;

571
	/* check if the old mount command had the same options */
572
	if (sbsec->flags & SE_SBINITIALIZED)
573 574 575 576 577 578 579
		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
	 */
580 581
	if (!(sbsec->flags & SE_SBINITIALIZED))
		if (mnt_flags & flag)
582 583 584
			return 1;
	return 0;
}
585

586 587 588 589
/*
 * Allow filesystems with binary mount data to explicitly set mount point
 * labeling information.
 */
590 591
static int selinux_set_mnt_opts(struct super_block *sb,
				struct security_mnt_opts *opts)
592
{
593
	const struct cred *cred = current_cred();
594 595
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
596 597
	struct inode *inode = sbsec->sb->s_root->d_inode;
	struct inode_security_struct *root_isec = inode->i_security;
598 599
	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
	u32 defcontext_sid = 0;
600 601 602
	char **mount_options = opts->mnt_opts;
	int *flags = opts->mnt_opts_flags;
	int num_opts = opts->num_mnt_opts;
603 604 605 606 607 608 609 610 611 612 613

	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
614 615
		printk(KERN_WARNING "SELinux: Unable to set superblock options "
			"before the security server is initialized\n");
L
Linus Torvalds 已提交
616
		goto out;
617
	}
L
Linus Torvalds 已提交
618

619 620 621 622 623 624 625 626 627 628 629
	/*
	 * 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)
	 */
630
	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
631
	    && (num_opts == 0))
632
		goto out;
633

634 635 636 637 638 639 640
	/*
	 * 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;
641

642
		if (flags[i] == SBLABEL_MNT)
643
			continue;
644 645
		rc = security_context_to_sid(mount_options[i],
					     strlen(mount_options[i]), &sid);
L
Linus Torvalds 已提交
646 647
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
648 649
			       "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n",
			       mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc);
650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
			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
694
		}
695 696
	}

697
	if (sbsec->flags & SE_SBINITIALIZED) {
698
		/* previously mounted with options, but not on this attempt? */
699
		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
700 701 702 703 704
			goto out_double_mount;
		rc = 0;
		goto out;
	}

705
	if (strcmp(sb->s_type->name, "proc") == 0)
706
		sbsec->flags |= SE_SBPROC;
707 708

	/* Determine the labeling behavior to use for this filesystem type. */
709
	rc = security_fs_use(sb);
710 711
	if (rc) {
		printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
712
		       __func__, sb->s_type->name, rc);
713 714
		goto out;
	}
L
Linus Torvalds 已提交
715

716 717
	/* sets the context of the superblock for the fs being mounted. */
	if (fscontext_sid) {
718
		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
L
Linus Torvalds 已提交
719
		if (rc)
720
			goto out;
L
Linus Torvalds 已提交
721

722
		sbsec->sid = fscontext_sid;
723 724 725 726 727 728 729
	}

	/*
	 * 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.
	 */
730 731
	if (context_sid) {
		if (!fscontext_sid) {
732 733
			rc = may_context_mount_sb_relabel(context_sid, sbsec,
							  cred);
734
			if (rc)
735 736
				goto out;
			sbsec->sid = context_sid;
737
		} else {
738 739
			rc = may_context_mount_inode_relabel(context_sid, sbsec,
							     cred);
740
			if (rc)
741
				goto out;
742
		}
743 744
		if (!rootcontext_sid)
			rootcontext_sid = context_sid;
L
Linus Torvalds 已提交
745

746
		sbsec->mntpoint_sid = context_sid;
747
		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
L
Linus Torvalds 已提交
748 749
	}

750
	if (rootcontext_sid) {
751 752
		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
						     cred);
753
		if (rc)
754
			goto out;
755

756 757
		root_isec->sid = rootcontext_sid;
		root_isec->initialized = 1;
758 759
	}

760 761 762 763 764 765
	if (defcontext_sid) {
		if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux: defcontext option is "
			       "invalid for this filesystem type\n");
			goto out;
L
Linus Torvalds 已提交
766 767
		}

768 769
		if (defcontext_sid != sbsec->def_sid) {
			rc = may_context_mount_inode_relabel(defcontext_sid,
770
							     sbsec, cred);
771 772 773
			if (rc)
				goto out;
		}
L
Linus Torvalds 已提交
774

775
		sbsec->def_sid = defcontext_sid;
L
Linus Torvalds 已提交
776 777
	}

778
	rc = sb_finish_set_opts(sb);
L
Linus Torvalds 已提交
779
out:
780
	mutex_unlock(&sbsec->lock);
L
Linus Torvalds 已提交
781
	return rc;
782 783 784
out_double_mount:
	rc = -EINVAL;
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
785 786
	       "security settings for (dev %s, type "SB_TYPE_FMT")\n", sb->s_id,
	       SB_TYPE_ARGS(sb));
787
	goto out;
L
Linus Torvalds 已提交
788 789
}

790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820
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) {
		struct inode_security_struct *oldroot = oldsb->s_root->d_inode->i_security;
		struct inode_security_struct *newroot = newsb->s_root->d_inode->i_security;
		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,
821
					struct super_block *newsb)
L
Linus Torvalds 已提交
822
{
823 824
	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
	struct superblock_security_struct *newsbsec = newsb->s_security;
L
Linus Torvalds 已提交
825

826 827 828
	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
829

830 831
	/*
	 * if the parent was able to be mounted it clearly had no special lsm
832
	 * mount options.  thus we can safely deal with this superblock later
833
	 */
834
	if (!ss_initialized)
835
		return 0;
836 837

	/* how can we clone if the old one wasn't set up?? */
838
	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
839

840
	/* if fs is reusing a sb, make sure that the contexts match */
841
	if (newsbsec->flags & SE_SBINITIALIZED)
842
		return selinux_cmp_sb_context(oldsb, newsb);
843

844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862
	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) {
			struct inode *newinode = newsb->s_root->d_inode;
			struct inode_security_struct *newisec = newinode->i_security;
			newisec->sid = sid;
		}
		newsbsec->mntpoint_sid = sid;
L
Linus Torvalds 已提交
863
	}
864 865 866 867 868
	if (set_rootcontext) {
		const struct inode *oldinode = oldsb->s_root->d_inode;
		const struct inode_security_struct *oldisec = oldinode->i_security;
		struct inode *newinode = newsb->s_root->d_inode;
		struct inode_security_struct *newisec = newinode->i_security;
L
Linus Torvalds 已提交
869

870
		newisec->sid = oldisec->sid;
L
Linus Torvalds 已提交
871 872
	}

873 874
	sb_finish_set_opts(newsb);
	mutex_unlock(&newsbsec->lock);
875
	return 0;
876 877
}

878 879
static int selinux_parse_opts_str(char *options,
				  struct security_mnt_opts *opts)
880
{
881
	char *p;
882 883
	char *context = NULL, *defcontext = NULL;
	char *fscontext = NULL, *rootcontext = NULL;
884
	int rc, num_mnt_opts = 0;
L
Linus Torvalds 已提交
885

886
	opts->num_mnt_opts = 0;
L
Linus Torvalds 已提交
887

888 889 890 891
	/* Standard string-based options. */
	while ((p = strsep(&options, "|")) != NULL) {
		int token;
		substring_t args[MAX_OPT_ARGS];
L
Linus Torvalds 已提交
892

893 894
		if (!*p)
			continue;
L
Linus Torvalds 已提交
895

896
		token = match_token(p, tokens, args);
L
Linus Torvalds 已提交
897

898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949
		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;
950 951
		case Opt_labelsupport:
			break;
952 953 954 955
		default:
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux:  unknown mount option\n");
			goto out_err;
L
Linus Torvalds 已提交
956 957 958

		}
	}
959

960 961 962 963 964 965 966 967 968 969 970
	rc = -ENOMEM;
	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts)
		goto out_err;

	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
		kfree(opts->mnt_opts);
		goto out_err;
	}

971
	if (fscontext) {
972 973
		opts->mnt_opts[num_mnt_opts] = fscontext;
		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
974 975
	}
	if (context) {
976 977
		opts->mnt_opts[num_mnt_opts] = context;
		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
978 979
	}
	if (rootcontext) {
980 981
		opts->mnt_opts[num_mnt_opts] = rootcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
982 983
	}
	if (defcontext) {
984 985
		opts->mnt_opts[num_mnt_opts] = defcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
986 987
	}

988 989 990
	opts->num_mnt_opts = num_mnt_opts;
	return 0;

991 992 993 994 995
out_err:
	kfree(context);
	kfree(defcontext);
	kfree(fscontext);
	kfree(rootcontext);
L
Linus Torvalds 已提交
996 997
	return rc;
}
998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024
/*
 * 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:
	rc = selinux_set_mnt_opts(sb, &opts);

out_err:
	security_free_mnt_opts(&opts);
	return rc;
}
L
Linus Torvalds 已提交
1025

A
Adrian Bunk 已提交
1026 1027
static void selinux_write_opts(struct seq_file *m,
			       struct security_mnt_opts *opts)
1028 1029 1030 1031 1032
{
	int i;
	char *prefix;

	for (i = 0; i < opts->num_mnt_opts; i++) {
1033 1034 1035 1036 1037 1038
		char *has_comma;

		if (opts->mnt_opts[i])
			has_comma = strchr(opts->mnt_opts[i], ',');
		else
			has_comma = NULL;
1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052

		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;
1053
		case SBLABEL_MNT:
1054 1055 1056
			seq_putc(m, ',');
			seq_puts(m, LABELSUPP_STR);
			continue;
1057 1058
		default:
			BUG();
1059
			return;
1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077
		};
		/* we need a comma before each option */
		seq_putc(m, ',');
		seq_puts(m, prefix);
		if (has_comma)
			seq_putc(m, '\"');
		seq_puts(m, opts->mnt_opts[i]);
		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);
1078 1079 1080 1081
	if (rc) {
		/* before policy load we may get EINVAL, don't show anything */
		if (rc == -EINVAL)
			rc = 0;
1082
		return rc;
1083
	}
1084 1085 1086 1087 1088 1089 1090 1091

	selinux_write_opts(m, &opts);

	security_free_mnt_opts(&opts);

	return rc;
}

L
Linus Torvalds 已提交
1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114
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;
}

1115 1116 1117 1118 1119 1120 1121 1122 1123 1124
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
1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140
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:
1141 1142 1143 1144
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
L
Linus Torvalds 已提交
1145
		case SOCK_DGRAM:
1146 1147 1148 1149
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
J
James Morris 已提交
1150 1151
		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
1152
		default:
L
Linus Torvalds 已提交
1153 1154 1155 1156 1157 1158 1159 1160 1161
			return SECCLASS_RAWIP_SOCKET;
		}
		break;
	case PF_NETLINK:
		switch (protocol) {
		case NETLINK_ROUTE:
			return SECCLASS_NETLINK_ROUTE_SOCKET;
		case NETLINK_FIREWALL:
			return SECCLASS_NETLINK_FIREWALL_SOCKET;
1162
		case NETLINK_SOCK_DIAG:
L
Linus Torvalds 已提交
1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175
			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;
		case NETLINK_AUDIT:
			return SECCLASS_NETLINK_AUDIT_SOCKET;
		case NETLINK_IP6_FW:
			return SECCLASS_NETLINK_IP6FW_SOCKET;
		case NETLINK_DNRTMSG:
			return SECCLASS_NETLINK_DNRT_SOCKET;
1176 1177
		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
L
Linus Torvalds 已提交
1178 1179 1180 1181 1182 1183 1184
		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
1185 1186
	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
L
Linus Torvalds 已提交
1187 1188 1189 1190 1191 1192
	}

	return SECCLASS_SOCKET;
}

#ifdef CONFIG_PROC_FS
1193
static int selinux_proc_get_sid(struct dentry *dentry,
L
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1194 1195 1196
				u16 tclass,
				u32 *sid)
{
1197 1198
	int rc;
	char *buffer, *path;
L
Linus Torvalds 已提交
1199

1200
	buffer = (char *)__get_free_page(GFP_KERNEL);
L
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1201 1202 1203
	if (!buffer)
		return -ENOMEM;

1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215
	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
	if (IS_ERR(path))
		rc = PTR_ERR(path);
	else {
		/* 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++;
		}
		rc = security_genfs_sid("proc", path, tclass, sid);
L
Linus Torvalds 已提交
1216 1217 1218 1219 1220
	}
	free_page((unsigned long)buffer);
	return rc;
}
#else
1221
static int selinux_proc_get_sid(struct dentry *dentry,
L
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1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243
				u16 tclass,
				u32 *sid)
{
	return -EINVAL;
}
#endif

/* 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;

	if (isec->initialized)
		goto out;

1244
	mutex_lock(&isec->lock);
L
Linus Torvalds 已提交
1245
	if (isec->initialized)
1246
		goto out_unlock;
L
Linus Torvalds 已提交
1247 1248

	sbsec = inode->i_sb->s_security;
1249
	if (!(sbsec->flags & SE_SBINITIALIZED)) {
L
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1250 1251 1252 1253 1254 1255 1256
		/* 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);
1257
		goto out_unlock;
L
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1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276
	}

	switch (sbsec->behavior) {
	case SECURITY_FS_USE_XATTR:
		if (!inode->i_op->getxattr) {
			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) {
1277 1278 1279 1280 1281 1282 1283 1284 1285
			/*
			 * 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.
			 */
1286
			goto out_unlock;
L
Linus Torvalds 已提交
1287 1288 1289
		}

		len = INITCONTEXTLEN;
1290
		context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1291 1292 1293
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
1294
			goto out_unlock;
L
Linus Torvalds 已提交
1295
		}
1296
		context[len] = '\0';
L
Linus Torvalds 已提交
1297 1298 1299
		rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
					   context, len);
		if (rc == -ERANGE) {
1300 1301
			kfree(context);

L
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1302 1303 1304 1305 1306
			/* Need a larger buffer.  Query for the right size. */
			rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
						   NULL, 0);
			if (rc < 0) {
				dput(dentry);
1307
				goto out_unlock;
L
Linus Torvalds 已提交
1308 1309
			}
			len = rc;
1310
			context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1311 1312 1313
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
1314
				goto out_unlock;
L
Linus Torvalds 已提交
1315
			}
1316
			context[len] = '\0';
L
Linus Torvalds 已提交
1317 1318 1319 1320 1321 1322 1323
			rc = inode->i_op->getxattr(dentry,
						   XATTR_NAME_SELINUX,
						   context, len);
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
E
Eric Paris 已提交
1324
				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1325
				       "%d for dev=%s ino=%ld\n", __func__,
L
Linus Torvalds 已提交
1326 1327
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
1328
				goto out_unlock;
L
Linus Torvalds 已提交
1329 1330 1331 1332 1333
			}
			/* Map ENODATA to the default file SID */
			sid = sbsec->def_sid;
			rc = 0;
		} else {
1334
			rc = security_context_to_sid_default(context, rc, &sid,
1335 1336
							     sbsec->def_sid,
							     GFP_NOFS);
L
Linus Torvalds 已提交
1337
			if (rc) {
1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350
				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
1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368
				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);
1369 1370
		rc = security_transition_sid(isec->task_sid, sbsec->sid,
					     isec->sclass, NULL, &sid);
L
Linus Torvalds 已提交
1371
		if (rc)
1372
			goto out_unlock;
L
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1373 1374
		isec->sid = sid;
		break;
1375 1376 1377
	case SECURITY_FS_USE_MNTPOINT:
		isec->sid = sbsec->mntpoint_sid;
		break;
L
Linus Torvalds 已提交
1378
	default:
1379
		/* Default to the fs superblock SID. */
L
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1380 1381
		isec->sid = sbsec->sid;

1382
		if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1383
			if (opt_dentry) {
L
Linus Torvalds 已提交
1384
				isec->sclass = inode_mode_to_security_class(inode->i_mode);
1385
				rc = selinux_proc_get_sid(opt_dentry,
L
Linus Torvalds 已提交
1386 1387 1388
							  isec->sclass,
							  &sid);
				if (rc)
1389
					goto out_unlock;
L
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1390 1391 1392 1393 1394 1395 1396 1397
				isec->sid = sid;
			}
		}
		break;
	}

	isec->initialized = 1;

1398 1399
out_unlock:
	mutex_unlock(&isec->lock);
L
Linus Torvalds 已提交
1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432
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
1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445
/*
 * 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);
}

1446
/*
1447
 * Check permission between a pair of tasks, e.g. signal checks,
1448 1449
 * fork check, ptrace check, etc.
 * tsk1 is the actor and tsk2 is the target
1450
 * - this uses the default subjective creds of tsk1
1451 1452 1453
 */
static int task_has_perm(const struct task_struct *tsk1,
			 const struct task_struct *tsk2,
L
Linus Torvalds 已提交
1454 1455
			 u32 perms)
{
1456 1457
	const struct task_security_struct *__tsec1, *__tsec2;
	u32 sid1, sid2;
L
Linus Torvalds 已提交
1458

1459 1460 1461 1462 1463
	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
1464 1465
}

1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481
/*
 * 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);
}

1482 1483 1484 1485
#if CAP_LAST_CAP > 63
#error Fix SELinux to handle capabilities > 63.
#endif

L
Linus Torvalds 已提交
1486
/* Check whether a task is allowed to use a capability. */
1487
static int cred_has_capability(const struct cred *cred,
1488
			       int cap, int audit)
L
Linus Torvalds 已提交
1489
{
1490
	struct common_audit_data ad;
1491
	struct av_decision avd;
1492
	u16 sclass;
1493
	u32 sid = cred_sid(cred);
1494
	u32 av = CAP_TO_MASK(cap);
1495
	int rc;
L
Linus Torvalds 已提交
1496

1497
	ad.type = LSM_AUDIT_DATA_CAP;
L
Linus Torvalds 已提交
1498 1499
	ad.u.cap = cap;

1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510
	switch (CAP_TO_INDEX(cap)) {
	case 0:
		sclass = SECCLASS_CAPABILITY;
		break;
	case 1:
		sclass = SECCLASS_CAPABILITY2;
		break;
	default:
		printk(KERN_ERR
		       "SELinux:  out of range capability %d\n", cap);
		BUG();
1511
		return -EINVAL;
1512
	}
1513

1514
	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1515 1516 1517 1518 1519
	if (audit == SECURITY_CAP_AUDIT) {
		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
		if (rc2)
			return rc2;
	}
1520
	return rc;
L
Linus Torvalds 已提交
1521 1522 1523 1524 1525 1526
}

/* Check whether a task is allowed to use a system operation. */
static int task_has_system(struct task_struct *tsk,
			   u32 perms)
{
1527
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
1528

1529
	return avc_has_perm(sid, SECINITSID_KERNEL,
L
Linus Torvalds 已提交
1530 1531 1532 1533 1534 1535
			    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). */
1536
static int inode_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1537 1538
			  struct inode *inode,
			  u32 perms,
1539 1540
			  struct common_audit_data *adp,
			  unsigned flags)
L
Linus Torvalds 已提交
1541 1542
{
	struct inode_security_struct *isec;
1543
	u32 sid;
L
Linus Torvalds 已提交
1544

1545 1546
	validate_creds(cred);

1547
	if (unlikely(IS_PRIVATE(inode)))
1548 1549
		return 0;

1550
	sid = cred_sid(cred);
L
Linus Torvalds 已提交
1551 1552
	isec = inode->i_security;

1553
	return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
L
Linus Torvalds 已提交
1554 1555 1556 1557 1558
}

/* 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. */
1559
static inline int dentry_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1560 1561 1562 1563
				  struct dentry *dentry,
				  u32 av)
{
	struct inode *inode = dentry->d_inode;
1564
	struct common_audit_data ad;
1565

1566
	ad.type = LSM_AUDIT_DATA_DENTRY;
E
Eric Paris 已提交
1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580
	ad.u.dentry = dentry;
	return inode_has_perm(cred, inode, av, &ad, 0);
}

/* 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,
				struct path *path,
				u32 av)
{
	struct inode *inode = path->dentry->d_inode;
	struct common_audit_data ad;

1581
	ad.type = LSM_AUDIT_DATA_PATH;
E
Eric Paris 已提交
1582
	ad.u.path = *path;
1583
	return inode_has_perm(cred, inode, av, &ad, 0);
L
Linus Torvalds 已提交
1584 1585 1586 1587 1588 1589 1590 1591 1592 1593
}

/* 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. */
1594 1595 1596
static int file_has_perm(const struct cred *cred,
			 struct file *file,
			 u32 av)
L
Linus Torvalds 已提交
1597 1598
{
	struct file_security_struct *fsec = file->f_security;
A
Al Viro 已提交
1599
	struct inode *inode = file_inode(file);
1600
	struct common_audit_data ad;
1601
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1602 1603
	int rc;

1604
	ad.type = LSM_AUDIT_DATA_PATH;
1605
	ad.u.path = file->f_path;
L
Linus Torvalds 已提交
1606

1607 1608
	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid,
L
Linus Torvalds 已提交
1609 1610 1611 1612
				  SECCLASS_FD,
				  FD__USE,
				  &ad);
		if (rc)
1613
			goto out;
L
Linus Torvalds 已提交
1614 1615 1616
	}

	/* av is zero if only checking access to the descriptor. */
1617
	rc = 0;
L
Linus Torvalds 已提交
1618
	if (av)
1619
		rc = inode_has_perm(cred, inode, av, &ad, 0);
L
Linus Torvalds 已提交
1620

1621 1622
out:
	return rc;
L
Linus Torvalds 已提交
1623 1624 1625 1626 1627 1628 1629
}

/* Check whether a task can create a file. */
static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
1630
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
1631 1632
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
1633
	u32 sid, newsid;
1634
	struct common_audit_data ad;
L
Linus Torvalds 已提交
1635 1636 1637 1638 1639
	int rc;

	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

1640 1641 1642
	sid = tsec->sid;
	newsid = tsec->create_sid;

1643
	ad.type = LSM_AUDIT_DATA_DENTRY;
1644
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1645

1646
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1647 1648 1649 1650 1651
			  DIR__ADD_NAME | DIR__SEARCH,
			  &ad);
	if (rc)
		return rc;

1652
	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
1653 1654
		rc = security_transition_sid(sid, dsec->sid, tclass,
					     &dentry->d_name, &newsid);
L
Linus Torvalds 已提交
1655 1656 1657 1658
		if (rc)
			return rc;
	}

1659
	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
L
Linus Torvalds 已提交
1660 1661 1662 1663 1664 1665 1666 1667
	if (rc)
		return rc;

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

1668 1669 1670 1671
/* Check whether a task can create a key. */
static int may_create_key(u32 ksid,
			  struct task_struct *ctx)
{
1672
	u32 sid = task_sid(ctx);
1673

1674
	return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1675 1676
}

1677 1678 1679
#define MAY_LINK	0
#define MAY_UNLINK	1
#define MAY_RMDIR	2
L
Linus Torvalds 已提交
1680 1681 1682 1683 1684 1685 1686 1687

/* 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;
1688
	struct common_audit_data ad;
1689
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1690 1691 1692 1693 1694 1695
	u32 av;
	int rc;

	dsec = dir->i_security;
	isec = dentry->d_inode->i_security;

1696
	ad.type = LSM_AUDIT_DATA_DENTRY;
1697
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1698 1699 1700

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1701
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715
	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
1716 1717
		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
			__func__, kind);
L
Linus Torvalds 已提交
1718 1719 1720
		return 0;
	}

1721
	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
L
Linus Torvalds 已提交
1722 1723 1724 1725 1726 1727 1728 1729 1730
	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;
1731
	struct common_audit_data ad;
1732
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1733 1734 1735 1736 1737 1738 1739 1740 1741
	u32 av;
	int old_is_dir, new_is_dir;
	int rc;

	old_dsec = old_dir->i_security;
	old_isec = old_dentry->d_inode->i_security;
	old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
	new_dsec = new_dir->i_security;

1742
	ad.type = LSM_AUDIT_DATA_DENTRY;
L
Linus Torvalds 已提交
1743

1744
	ad.u.dentry = old_dentry;
1745
	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1746 1747 1748
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
1749
	rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1750 1751 1752 1753
			  old_isec->sclass, FILE__RENAME, &ad);
	if (rc)
		return rc;
	if (old_is_dir && new_dir != old_dir) {
1754
		rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1755 1756 1757 1758 1759
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

1760
	ad.u.dentry = new_dentry;
L
Linus Torvalds 已提交
1761 1762 1763
	av = DIR__ADD_NAME | DIR__SEARCH;
	if (new_dentry->d_inode)
		av |= DIR__REMOVE_NAME;
1764
	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1765 1766 1767 1768 1769
	if (rc)
		return rc;
	if (new_dentry->d_inode) {
		new_isec = new_dentry->d_inode->i_security;
		new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1770
		rc = avc_has_perm(sid, new_isec->sid,
L
Linus Torvalds 已提交
1771 1772 1773 1774 1775 1776 1777 1778 1779 1780
				  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. */
1781
static int superblock_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1782 1783
			       struct super_block *sb,
			       u32 perms,
1784
			       struct common_audit_data *ad)
L
Linus Torvalds 已提交
1785 1786
{
	struct superblock_security_struct *sbsec;
1787
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1788 1789

	sbsec = sb->s_security;
1790
	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
L
Linus Torvalds 已提交
1791 1792 1793 1794 1795 1796 1797
}

/* 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
1798
	if (!S_ISDIR(mode)) {
L
Linus Torvalds 已提交
1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820
		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;
}

1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843
/* 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
1844
/*
1845
 * Convert a file to an access vector and include the correct open
E
Eric Paris 已提交
1846 1847
 * open permission.
 */
1848
static inline u32 open_file_to_av(struct file *file)
E
Eric Paris 已提交
1849
{
1850
	u32 av = file_to_av(file);
E
Eric Paris 已提交
1851

1852 1853 1854
	if (selinux_policycap_openperm)
		av |= FILE__OPEN;

E
Eric Paris 已提交
1855 1856 1857
	return av;
}

L
Linus Torvalds 已提交
1858 1859
/* Hook functions begin here. */

1860
static int selinux_ptrace_access_check(struct task_struct *child,
1861
				     unsigned int mode)
L
Linus Torvalds 已提交
1862 1863 1864
{
	int rc;

1865
	rc = cap_ptrace_access_check(child, mode);
L
Linus Torvalds 已提交
1866 1867 1868
	if (rc)
		return rc;

1869
	if (mode & PTRACE_MODE_READ) {
1870 1871 1872
		u32 sid = current_sid();
		u32 csid = task_sid(child);
		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1873 1874
	}

1875
	return current_has_perm(child, PROCESS__PTRACE);
1876 1877 1878 1879 1880 1881
}

static int selinux_ptrace_traceme(struct task_struct *parent)
{
	int rc;

1882
	rc = cap_ptrace_traceme(parent);
1883 1884 1885 1886
	if (rc)
		return rc;

	return task_has_perm(parent, current, PROCESS__PTRACE);
L
Linus Torvalds 已提交
1887 1888 1889
}

static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1890
			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
L
Linus Torvalds 已提交
1891 1892 1893
{
	int error;

1894
	error = current_has_perm(target, PROCESS__GETCAP);
L
Linus Torvalds 已提交
1895 1896 1897
	if (error)
		return error;

1898
	return cap_capget(target, effective, inheritable, permitted);
L
Linus Torvalds 已提交
1899 1900
}

D
David Howells 已提交
1901 1902 1903 1904
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
1905 1906 1907
{
	int error;

1908
	error = cap_capset(new, old,
D
David Howells 已提交
1909
				      effective, inheritable, permitted);
L
Linus Torvalds 已提交
1910 1911 1912
	if (error)
		return error;

D
David Howells 已提交
1913
	return cred_has_perm(old, new, PROCESS__SETCAP);
L
Linus Torvalds 已提交
1914 1915
}

1916 1917 1918 1919 1920 1921 1922 1923 1924 1925
/*
 * (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.
 */

1926 1927
static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
			   int cap, int audit)
L
Linus Torvalds 已提交
1928 1929 1930
{
	int rc;

1931
	rc = cap_capable(cred, ns, cap, audit);
L
Linus Torvalds 已提交
1932 1933 1934
	if (rc)
		return rc;

1935
	return cred_has_capability(cred, cap, audit);
L
Linus Torvalds 已提交
1936 1937 1938 1939
}

static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
{
1940
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
1941 1942 1943 1944 1945 1946
	int rc = 0;

	if (!sb)
		return 0;

	switch (cmds) {
1947 1948 1949 1950 1951
	case Q_SYNC:
	case Q_QUOTAON:
	case Q_QUOTAOFF:
	case Q_SETINFO:
	case Q_SETQUOTA:
1952
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1953 1954 1955 1956
		break;
	case Q_GETFMT:
	case Q_GETINFO:
	case Q_GETQUOTA:
1957
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1958 1959 1960 1961
		break;
	default:
		rc = 0;  /* let the kernel handle invalid cmds */
		break;
L
Linus Torvalds 已提交
1962 1963 1964 1965 1966 1967
	}
	return rc;
}

static int selinux_quota_on(struct dentry *dentry)
{
1968 1969
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
1970
	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
L
Linus Torvalds 已提交
1971 1972
}

1973
static int selinux_syslog(int type)
L
Linus Torvalds 已提交
1974 1975 1976 1977
{
	int rc;

	switch (type) {
1978 1979
	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
1980 1981
		rc = task_has_system(current, SYSTEM__SYSLOG_READ);
		break;
1982 1983 1984 1985
	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:
1986 1987
		rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
		break;
1988 1989 1990 1991 1992
	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 */
1993 1994 1995
	default:
		rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
		break;
L
Linus Torvalds 已提交
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
	}
	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.
 */
2008
static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
L
Linus Torvalds 已提交
2009 2010 2011
{
	int rc, cap_sys_admin = 0;

2012
	rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
2013
			     SECURITY_CAP_NOAUDIT);
L
Linus Torvalds 已提交
2014 2015 2016
	if (rc == 0)
		cap_sys_admin = 1;

2017
	return __vm_enough_memory(mm, pages, cap_sys_admin);
L
Linus Torvalds 已提交
2018 2019 2020 2021
}

/* binprm security operations */

2022
static int selinux_bprm_set_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2023
{
2024 2025
	const struct task_security_struct *old_tsec;
	struct task_security_struct *new_tsec;
L
Linus Torvalds 已提交
2026
	struct inode_security_struct *isec;
2027
	struct common_audit_data ad;
A
Al Viro 已提交
2028
	struct inode *inode = file_inode(bprm->file);
L
Linus Torvalds 已提交
2029 2030
	int rc;

2031
	rc = cap_bprm_set_creds(bprm);
L
Linus Torvalds 已提交
2032 2033 2034
	if (rc)
		return rc;

2035 2036 2037
	/* SELinux context only depends on initial program or script and not
	 * the script interpreter */
	if (bprm->cred_prepared)
L
Linus Torvalds 已提交
2038 2039
		return 0;

2040 2041
	old_tsec = current_security();
	new_tsec = bprm->cred->security;
L
Linus Torvalds 已提交
2042 2043 2044
	isec = inode->i_security;

	/* Default to the current task SID. */
2045 2046
	new_tsec->sid = old_tsec->sid;
	new_tsec->osid = old_tsec->sid;
L
Linus Torvalds 已提交
2047

2048
	/* Reset fs, key, and sock SIDs on execve. */
2049 2050 2051
	new_tsec->create_sid = 0;
	new_tsec->keycreate_sid = 0;
	new_tsec->sockcreate_sid = 0;
L
Linus Torvalds 已提交
2052

2053 2054
	if (old_tsec->exec_sid) {
		new_tsec->sid = old_tsec->exec_sid;
L
Linus Torvalds 已提交
2055
		/* Reset exec SID on execve. */
2056
		new_tsec->exec_sid = 0;
2057 2058 2059 2060 2061 2062 2063

		/*
		 * Minimize confusion: if no_new_privs and a transition is
		 * explicitly requested, then fail the exec.
		 */
		if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
			return -EPERM;
L
Linus Torvalds 已提交
2064 2065
	} else {
		/* Check for a default transition on this program. */
2066
		rc = security_transition_sid(old_tsec->sid, isec->sid,
2067 2068
					     SECCLASS_PROCESS, NULL,
					     &new_tsec->sid);
L
Linus Torvalds 已提交
2069 2070 2071 2072
		if (rc)
			return rc;
	}

2073
	ad.type = LSM_AUDIT_DATA_PATH;
2074
	ad.u.path = bprm->file->f_path;
L
Linus Torvalds 已提交
2075

2076 2077
	if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) ||
	    (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS))
2078
		new_tsec->sid = old_tsec->sid;
L
Linus Torvalds 已提交
2079

2080 2081
	if (new_tsec->sid == old_tsec->sid) {
		rc = avc_has_perm(old_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2082 2083 2084 2085 2086
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		/* Check permissions for the transition. */
2087
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
L
Linus Torvalds 已提交
2088 2089 2090 2091
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

2092
		rc = avc_has_perm(new_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2093 2094 2095 2096
				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
		if (rc)
			return rc;

2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114
		/* 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)) {
			struct task_struct *tracer;
			struct task_security_struct *sec;
			u32 ptsid = 0;

			rcu_read_lock();
2115
			tracer = ptrace_parent(current);
2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
			if (likely(tracer != NULL)) {
				sec = __task_cred(tracer)->security;
				ptsid = sec->sid;
			}
			rcu_read_unlock();

			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
2130

2131 2132
		/* Clear any possibly unsafe personality bits on exec: */
		bprm->per_clear |= PER_CLEAR_ON_SETID;
L
Linus Torvalds 已提交
2133 2134 2135 2136 2137
	}

	return 0;
}

2138
static int selinux_bprm_secureexec(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2139
{
2140
	const struct task_security_struct *tsec = current_security();
2141
	u32 sid, osid;
L
Linus Torvalds 已提交
2142 2143
	int atsecure = 0;

2144 2145 2146 2147
	sid = tsec->sid;
	osid = tsec->osid;

	if (osid != sid) {
L
Linus Torvalds 已提交
2148 2149 2150
		/* Enable secure mode for SIDs transitions unless
		   the noatsecure permission is granted between
		   the two SIDs, i.e. ahp returns 0. */
2151
		atsecure = avc_has_perm(osid, sid,
2152 2153
					SECCLASS_PROCESS,
					PROCESS__NOATSECURE, NULL);
L
Linus Torvalds 已提交
2154 2155
	}

2156
	return (atsecure || cap_bprm_secureexec(bprm));
L
Linus Torvalds 已提交
2157 2158
}

A
Al Viro 已提交
2159 2160 2161 2162 2163
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
2164
/* Derived from fs/exec.c:flush_old_files. */
2165 2166
static inline void flush_unauthorized_files(const struct cred *cred,
					    struct files_struct *files)
L
Linus Torvalds 已提交
2167 2168
{
	struct file *file, *devnull = NULL;
2169
	struct tty_struct *tty;
2170
	int drop_tty = 0;
A
Al Viro 已提交
2171
	unsigned n;
L
Linus Torvalds 已提交
2172

2173
	tty = get_current_tty();
L
Linus Torvalds 已提交
2174
	if (tty) {
N
Nick Piggin 已提交
2175
		spin_lock(&tty_files_lock);
2176
		if (!list_empty(&tty->tty_files)) {
N
Nick Piggin 已提交
2177
			struct tty_file_private *file_priv;
2178

L
Linus Torvalds 已提交
2179
			/* Revalidate access to controlling tty.
2180
			   Use path_has_perm on the tty path directly rather
L
Linus Torvalds 已提交
2181 2182 2183
			   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
2184 2185 2186
			file_priv = list_first_entry(&tty->tty_files,
						struct tty_file_private, list);
			file = file_priv->file;
2187
			if (path_has_perm(cred, &file->f_path, FILE__READ | FILE__WRITE))
2188
				drop_tty = 1;
L
Linus Torvalds 已提交
2189
		}
N
Nick Piggin 已提交
2190
		spin_unlock(&tty_files_lock);
A
Alan Cox 已提交
2191
		tty_kref_put(tty);
L
Linus Torvalds 已提交
2192
	}
2193 2194 2195
	/* Reset controlling tty. */
	if (drop_tty)
		no_tty();
L
Linus Torvalds 已提交
2196 2197

	/* Revalidate access to inherited open files. */
A
Al Viro 已提交
2198 2199 2200
	n = iterate_fd(files, 0, match_file, cred);
	if (!n) /* none found? */
		return;
L
Linus Torvalds 已提交
2201

A
Al Viro 已提交
2202
	devnull = dentry_open(&selinux_null, O_RDWR, cred);
A
Al Viro 已提交
2203 2204 2205 2206 2207 2208 2209
	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
2210
		fput(devnull);
L
Linus Torvalds 已提交
2211 2212
}

2213 2214 2215 2216
/*
 * 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
2217
{
2218 2219 2220
	struct task_security_struct *new_tsec;
	struct rlimit *rlim, *initrlim;
	int rc, i;
D
David Howells 已提交
2221

2222 2223 2224
	new_tsec = bprm->cred->security;
	if (new_tsec->sid == new_tsec->osid)
		return;
L
Linus Torvalds 已提交
2225

2226 2227
	/* Close files for which the new task SID is not authorized. */
	flush_unauthorized_files(bprm->cred, current->files);
R
Roland McGrath 已提交
2228

2229 2230
	/* Always clear parent death signal on SID transitions. */
	current->pdeath_signal = 0;
R
Roland McGrath 已提交
2231

2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244
	/* 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) {
2245 2246
		/* protect against do_prlimit() */
		task_lock(current);
2247 2248 2249 2250
		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
2251
		}
2252 2253
		task_unlock(current);
		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
L
Linus Torvalds 已提交
2254 2255 2256 2257
	}
}

/*
2258 2259
 * Clean up the process immediately after the installation of new credentials
 * due to exec
L
Linus Torvalds 已提交
2260
 */
2261
static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2262
{
2263
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
2264
	struct itimerval itimer;
2265
	u32 osid, sid;
L
Linus Torvalds 已提交
2266 2267
	int rc, i;

2268 2269 2270 2271
	osid = tsec->osid;
	sid = tsec->sid;

	if (sid == osid)
L
Linus Torvalds 已提交
2272 2273
		return;

2274 2275 2276 2277 2278 2279 2280 2281
	/* 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
2282 2283 2284 2285 2286
	if (rc) {
		memset(&itimer, 0, sizeof itimer);
		for (i = 0; i < 3; i++)
			do_setitimer(i, &itimer, NULL);
		spin_lock_irq(&current->sighand->siglock);
2287 2288 2289 2290 2291
		if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
			__flush_signals(current);
			flush_signal_handlers(current, 1);
			sigemptyset(&current->blocked);
		}
L
Linus Torvalds 已提交
2292 2293 2294
		spin_unlock_irq(&current->sighand->siglock);
	}

2295 2296
	/* Wake up the parent if it is waiting so that it can recheck
	 * wait permission to the new task SID. */
2297
	read_lock(&tasklist_lock);
2298
	__wake_up_parent(current, current->real_parent);
2299
	read_unlock(&tasklist_lock);
L
Linus Torvalds 已提交
2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323
}

/* 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)
{
2324 2325 2326
	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) ||
2327 2328
		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
2329 2330 2331 2332 2333 2334 2335
}

static inline void take_option(char **to, char *from, int *first, int len)
{
	if (!*first) {
		**to = ',';
		*to += 1;
2336
	} else
L
Linus Torvalds 已提交
2337 2338 2339 2340 2341
		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}

2342 2343
static inline void take_selinux_option(char **to, char *from, int *first,
				       int len)
2344 2345 2346 2347 2348 2349
{
	int current_size = 0;

	if (!*first) {
		**to = '|';
		*to += 1;
2350
	} else
2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362
		*first = 0;

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

2363
static int selinux_sb_copy_data(char *orig, char *copy)
L
Linus Torvalds 已提交
2364 2365 2366 2367
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_curr, *in_end;
	char *sec_curr, *nosec_save, *nosec;
2368
	int open_quote = 0;
L
Linus Torvalds 已提交
2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383

	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 {
2384 2385 2386 2387
		if (*in_end == '"')
			open_quote = !open_quote;
		if ((*in_end == ',' && open_quote == 0) ||
				*in_end == '\0') {
L
Linus Torvalds 已提交
2388 2389 2390
			int len = in_end - in_curr;

			if (selinux_option(in_curr, len))
2391
				take_selinux_option(&sec_curr, in_curr, &fsec, len);
L
Linus Torvalds 已提交
2392 2393 2394 2395 2396 2397 2398
			else
				take_option(&nosec, in_curr, &fnosec, len);

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

2399
	strcpy(in_save, nosec_save);
2400
	free_page((unsigned long)nosec_save);
L
Linus Torvalds 已提交
2401 2402 2403 2404
out:
	return rc;
}

2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439
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;
		size_t len;

2440
		if (flags[i] == SBLABEL_MNT)
2441 2442 2443 2444 2445
			continue;
		len = strlen(mount_options[i]);
		rc = security_context_to_sid(mount_options[i], len, &sid);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
2446 2447
			       "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n",
			       mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc);
2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484
			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;
			root_isec = sb->s_root->d_inode->i_security;

			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 "
2485 2486
	       "during remount (dev %s, type "SB_TYPE_FMT")\n", sb->s_id,
	       SB_TYPE_ARGS(sb));
2487 2488 2489
	goto out_free_opts;
}

2490
static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
L
Linus Torvalds 已提交
2491
{
2492
	const struct cred *cred = current_cred();
2493
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2494 2495 2496 2497 2498 2499
	int rc;

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

2500 2501 2502 2503
	/* Allow all mounts performed by the kernel */
	if (flags & MS_KERNMOUNT)
		return 0;

2504
	ad.type = LSM_AUDIT_DATA_DENTRY;
2505
	ad.u.dentry = sb->s_root;
2506
	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
L
Linus Torvalds 已提交
2507 2508
}

2509
static int selinux_sb_statfs(struct dentry *dentry)
L
Linus Torvalds 已提交
2510
{
2511
	const struct cred *cred = current_cred();
2512
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2513

2514
	ad.type = LSM_AUDIT_DATA_DENTRY;
2515
	ad.u.dentry = dentry->d_sb->s_root;
2516
	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
L
Linus Torvalds 已提交
2517 2518
}

A
Al Viro 已提交
2519
static int selinux_mount(const char *dev_name,
2520
			 struct path *path,
A
Al Viro 已提交
2521
			 const char *type,
2522 2523
			 unsigned long flags,
			 void *data)
L
Linus Torvalds 已提交
2524
{
2525
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2526 2527

	if (flags & MS_REMOUNT)
2528
		return superblock_has_perm(cred, path->dentry->d_sb,
2529
					   FILESYSTEM__REMOUNT, NULL);
L
Linus Torvalds 已提交
2530
	else
E
Eric Paris 已提交
2531
		return path_has_perm(cred, path, FILE__MOUNTON);
L
Linus Torvalds 已提交
2532 2533 2534 2535
}

static int selinux_umount(struct vfsmount *mnt, int flags)
{
2536
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2537

2538
	return superblock_has_perm(cred, mnt->mnt_sb,
2539
				   FILESYSTEM__UNMOUNT, NULL);
L
Linus Torvalds 已提交
2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553
}

/* 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);
}

2554
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2555 2556
				       const struct qstr *qstr, char **name,
				       void **value, size_t *len)
2557
{
2558
	const struct task_security_struct *tsec = current_security();
2559 2560
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
2561
	u32 sid, newsid, clen;
2562
	int rc;
2563
	char *namep = NULL, *context;
2564 2565 2566 2567

	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

2568 2569 2570
	sid = tsec->sid;
	newsid = tsec->create_sid;

2571 2572 2573
	if ((sbsec->flags & SE_SBINITIALIZED) &&
	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
		newsid = sbsec->mntpoint_sid;
2574
	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
2575
		rc = security_transition_sid(sid, dsec->sid,
2576
					     inode_mode_to_security_class(inode->i_mode),
2577
					     qstr, &newsid);
2578 2579 2580 2581
		if (rc) {
			printk(KERN_WARNING "%s:  "
			       "security_transition_sid failed, rc=%d (dev=%s "
			       "ino=%ld)\n",
2582
			       __func__,
2583 2584 2585 2586 2587
			       -rc, inode->i_sb->s_id, inode->i_ino);
			return rc;
		}
	}

2588
	/* Possibly defer initialization to selinux_complete_init. */
2589
	if (sbsec->flags & SE_SBINITIALIZED) {
2590 2591 2592 2593 2594
		struct inode_security_struct *isec = inode->i_security;
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		isec->sid = newsid;
		isec->initialized = 1;
	}
2595

2596
	if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
2597 2598
		return -EOPNOTSUPP;

2599
	if (name) {
2600
		namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2601 2602 2603 2604
		if (!namep)
			return -ENOMEM;
		*name = namep;
	}
2605

2606
	if (value && len) {
2607
		rc = security_sid_to_context_force(newsid, &context, &clen);
2608 2609 2610 2611 2612 2613
		if (rc) {
			kfree(namep);
			return rc;
		}
		*value = context;
		*len = clen;
2614 2615 2616 2617 2618
	}

	return 0;
}

A
Al Viro 已提交
2619
static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638
{
	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);
}

2639
static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
L
Linus Torvalds 已提交
2640 2641 2642 2643 2644 2645 2646 2647 2648
{
	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
2649
static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
L
Linus Torvalds 已提交
2650 2651 2652 2653 2654
{
	return may_create(dir, dentry, inode_mode_to_security_class(mode));
}

static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2655
				struct inode *new_inode, struct dentry *new_dentry)
L
Linus Torvalds 已提交
2656 2657 2658 2659 2660 2661
{
	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
}

static int selinux_inode_readlink(struct dentry *dentry)
{
2662 2663
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2664
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
2665 2666 2667 2668
}

static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
{
2669
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2670

E
Eric Paris 已提交
2671
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
2672 2673
}

2674 2675 2676
static noinline int audit_inode_permission(struct inode *inode,
					   u32 perms, u32 audited, u32 denied,
					   unsigned flags)
L
Linus Torvalds 已提交
2677
{
2678
	struct common_audit_data ad;
2679 2680 2681
	struct inode_security_struct *isec = inode->i_security;
	int rc;

2682
	ad.type = LSM_AUDIT_DATA_INODE;
2683 2684 2685 2686 2687 2688 2689 2690 2691
	ad.u.inode = inode;

	rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
			    audited, denied, &ad, flags);
	if (rc)
		return rc;
	return 0;
}

2692
static int selinux_inode_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
2693
{
2694
	const struct cred *cred = current_cred();
2695 2696
	u32 perms;
	bool from_access;
2697
	unsigned flags = mask & MAY_NOT_BLOCK;
2698 2699 2700 2701 2702
	struct inode_security_struct *isec;
	u32 sid;
	struct av_decision avd;
	int rc, rc2;
	u32 audited, denied;
L
Linus Torvalds 已提交
2703

2704
	from_access = mask & MAY_ACCESS;
2705 2706
	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);

2707 2708
	/* No permission to check.  Existence test. */
	if (!mask)
L
Linus Torvalds 已提交
2709 2710
		return 0;

2711
	validate_creds(cred);
2712

2713 2714
	if (unlikely(IS_PRIVATE(inode)))
		return 0;
2715 2716 2717

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

2718 2719 2720 2721 2722 2723 2724 2725 2726 2727
	sid = cred_sid(cred);
	isec = inode->i_security;

	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;

2728
	rc2 = audit_inode_permission(inode, perms, audited, denied, flags);
2729 2730 2731
	if (rc2)
		return rc2;
	return rc;
L
Linus Torvalds 已提交
2732 2733 2734 2735
}

static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
2736
	const struct cred *cred = current_cred();
2737
	unsigned int ia_valid = iattr->ia_valid;
2738
	__u32 av = FILE__WRITE;
L
Linus Torvalds 已提交
2739

2740 2741 2742 2743 2744 2745 2746
	/* 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
2747

2748 2749
	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
E
Eric Paris 已提交
2750
		return dentry_has_perm(cred, dentry, FILE__SETATTR);
L
Linus Torvalds 已提交
2751

2752
	if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE))
2753 2754 2755
		av |= FILE__OPEN;

	return dentry_has_perm(cred, dentry, av);
L
Linus Torvalds 已提交
2756 2757 2758 2759
}

static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
2760
	const struct cred *cred = current_cred();
E
Eric Paris 已提交
2761 2762 2763 2764
	struct path path;

	path.dentry = dentry;
	path.mnt = mnt;
2765

E
Eric Paris 已提交
2766
	return path_has_perm(cred, &path, FILE__GETATTR);
L
Linus Torvalds 已提交
2767 2768
}

2769
static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2770
{
2771 2772
	const struct cred *cred = current_cred();

2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786
	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
2787
	return dentry_has_perm(cred, dentry, FILE__SETATTR);
2788 2789
}

2790 2791
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
2792 2793 2794 2795
{
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec;
2796
	struct common_audit_data ad;
2797
	u32 newsid, sid = current_sid();
L
Linus Torvalds 已提交
2798 2799
	int rc = 0;

2800 2801
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
2802 2803

	sbsec = inode->i_sb->s_security;
2804
	if (!(sbsec->flags & SBLABEL_MNT))
L
Linus Torvalds 已提交
2805 2806
		return -EOPNOTSUPP;

2807
	if (!inode_owner_or_capable(inode))
L
Linus Torvalds 已提交
2808 2809
		return -EPERM;

2810
	ad.type = LSM_AUDIT_DATA_DENTRY;
2811
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
2812

2813
	rc = avc_has_perm(sid, isec->sid, isec->sclass,
L
Linus Torvalds 已提交
2814 2815 2816 2817 2818
			  FILE__RELABELFROM, &ad);
	if (rc)
		return rc;

	rc = security_context_to_sid(value, size, &newsid);
2819
	if (rc == -EINVAL) {
2820 2821 2822 2823 2824 2825 2826
		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 */
2827 2828 2829 2830 2831 2832 2833 2834 2835 2836
			if (value) {
				str = value;
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
			} else {
				str = "";
				audit_size = 0;
			}
2837 2838 2839 2840 2841
			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);

2842
			return rc;
2843
		}
2844 2845
		rc = security_context_to_sid_force(value, size, &newsid);
	}
L
Linus Torvalds 已提交
2846 2847 2848
	if (rc)
		return rc;

2849
	rc = avc_has_perm(sid, newsid, isec->sclass,
L
Linus Torvalds 已提交
2850 2851 2852 2853
			  FILE__RELABELTO, &ad);
	if (rc)
		return rc;

2854
	rc = security_validate_transition(isec->sid, newsid, sid,
2855
					  isec->sclass);
L
Linus Torvalds 已提交
2856 2857 2858 2859 2860 2861 2862 2863 2864 2865
	if (rc)
		return rc;

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

2866
static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2867
					const void *value, size_t size,
2868
					int flags)
L
Linus Torvalds 已提交
2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879
{
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	u32 newsid;
	int rc;

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

2880
	rc = security_context_to_sid_force(value, size, &newsid);
L
Linus Torvalds 已提交
2881
	if (rc) {
2882 2883 2884
		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
2885 2886 2887 2888 2889 2890 2891
		return;
	}

	isec->sid = newsid;
	return;
}

2892
static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
2893
{
2894 2895
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2896
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
2897 2898
}

2899
static int selinux_inode_listxattr(struct dentry *dentry)
L
Linus Torvalds 已提交
2900
{
2901 2902
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2903
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
2904 2905
}

2906
static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
2907
{
2908 2909
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
2910 2911 2912 2913 2914 2915

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

2916
/*
2917
 * Copy the inode security context value to the user.
2918 2919 2920
 *
 * Permission check is handled by selinux_inode_getxattr hook.
 */
2921
static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
L
Linus Torvalds 已提交
2922
{
2923 2924 2925
	u32 size;
	int error;
	char *context = NULL;
L
Linus Torvalds 已提交
2926
	struct inode_security_struct *isec = inode->i_security;
2927

2928 2929
	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;
2930

2931 2932 2933 2934 2935 2936 2937 2938 2939
	/*
	 * 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.
	 */
2940
	error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
2941
				SECURITY_CAP_NOAUDIT);
2942 2943 2944 2945 2946
	if (!error)
		error = security_sid_to_context_force(isec->sid, &context,
						      &size);
	else
		error = security_sid_to_context(isec->sid, &context, &size);
2947 2948 2949 2950 2951 2952 2953 2954 2955 2956
	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
2957 2958 2959
}

static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2960
				     const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971
{
	struct inode_security_struct *isec = inode->i_security;
	u32 newsid;
	int rc;

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

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

2972
	rc = security_context_to_sid((void *)value, size, &newsid);
L
Linus Torvalds 已提交
2973 2974 2975 2976
	if (rc)
		return rc;

	isec->sid = newsid;
2977
	isec->initialized = 1;
L
Linus Torvalds 已提交
2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988
	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;
}

2989 2990 2991 2992 2993 2994
static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
{
	struct inode_security_struct *isec = inode->i_security;
	*secid = isec->sid;
}

L
Linus Torvalds 已提交
2995 2996
/* file security operations */

2997
static int selinux_revalidate_file_permission(struct file *file, int mask)
L
Linus Torvalds 已提交
2998
{
2999
	const struct cred *cred = current_cred();
A
Al Viro 已提交
3000
	struct inode *inode = file_inode(file);
L
Linus Torvalds 已提交
3001 3002 3003 3004 3005

	/* 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;

3006 3007
	return file_has_perm(cred, file,
			     file_mask_to_av(inode->i_mode, mask));
L
Linus Torvalds 已提交
3008 3009
}

3010 3011
static int selinux_file_permission(struct file *file, int mask)
{
A
Al Viro 已提交
3012
	struct inode *inode = file_inode(file);
3013 3014 3015 3016
	struct file_security_struct *fsec = file->f_security;
	struct inode_security_struct *isec = inode->i_security;
	u32 sid = current_sid();

3017
	if (!mask)
3018 3019 3020
		/* No permission to check.  Existence test. */
		return 0;

3021 3022
	if (sid == fsec->sid && fsec->isid == isec->sid &&
	    fsec->pseqno == avc_policy_seqno())
3023
		/* No change since file_open check. */
3024 3025
		return 0;

3026 3027 3028
	return selinux_revalidate_file_permission(file, mask);
}

L
Linus Torvalds 已提交
3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041
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);
}

static int selinux_file_ioctl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3042
	const struct cred *cred = current_cred();
3043
	int error = 0;
L
Linus Torvalds 已提交
3044

3045 3046 3047 3048 3049 3050 3051
	switch (cmd) {
	case FIONREAD:
	/* fall through */
	case FIBMAP:
	/* fall through */
	case FIGETBSZ:
	/* fall through */
3052
	case FS_IOC_GETFLAGS:
3053
	/* fall through */
3054
	case FS_IOC_GETVERSION:
3055 3056
		error = file_has_perm(cred, file, FILE__GETATTR);
		break;
L
Linus Torvalds 已提交
3057

3058
	case FS_IOC_SETFLAGS:
3059
	/* fall through */
3060
	case FS_IOC_SETVERSION:
3061 3062 3063 3064 3065 3066 3067 3068 3069
		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
3070

3071 3072
	case KDSKBENT:
	case KDSKBSENT:
3073 3074
		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
					    SECURITY_CAP_AUDIT);
3075 3076 3077 3078 3079 3080 3081 3082 3083
		break;

	/* default case assumes that the command will go
	 * to the file's ioctl() function.
	 */
	default:
		error = file_has_perm(cred, file, FILE__IOCTL);
	}
	return error;
L
Linus Torvalds 已提交
3084 3085
}

3086 3087
static int default_noexec;

L
Linus Torvalds 已提交
3088 3089
static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
3090
	const struct cred *cred = current_cred();
D
David Howells 已提交
3091
	int rc = 0;
3092

3093 3094
	if (default_noexec &&
	    (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
L
Linus Torvalds 已提交
3095 3096 3097 3098 3099
		/*
		 * 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
3100
		rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
L
Linus Torvalds 已提交
3101
		if (rc)
D
David Howells 已提交
3102
			goto error;
L
Linus Torvalds 已提交
3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115
	}

	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;

3116
		return file_has_perm(cred, file, av);
L
Linus Torvalds 已提交
3117
	}
D
David Howells 已提交
3118 3119 3120

error:
	return rc;
L
Linus Torvalds 已提交
3121 3122
}

3123
static int selinux_mmap_addr(unsigned long addr)
L
Linus Torvalds 已提交
3124
{
3125
	int rc = 0;
3126
	u32 sid = current_sid();
L
Linus Torvalds 已提交
3127

3128 3129 3130 3131 3132 3133
	/*
	 * notice that we are intentionally putting the SELinux check before
	 * the secondary cap_file_mmap check.  This is such a likely attempt
	 * at bad behaviour/exploit that we always want to get the AVC, even
	 * if DAC would have also denied the operation.
	 */
3134
	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3135 3136
		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
				  MEMPROTECT__MMAP_ZERO, NULL);
3137 3138 3139 3140 3141
		if (rc)
			return rc;
	}

	/* do DAC check on address space usage */
3142 3143
	return cap_mmap_addr(addr);
}
L
Linus Torvalds 已提交
3144

3145 3146 3147
static int selinux_mmap_file(struct file *file, unsigned long reqprot,
			     unsigned long prot, unsigned long flags)
{
L
Linus Torvalds 已提交
3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158
	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)
{
3159
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3160 3161 3162 3163

	if (selinux_checkreqprot)
		prot = reqprot;

3164 3165
	if (default_noexec &&
	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3166
		int rc = 0;
3167 3168
		if (vma->vm_start >= vma->vm_mm->start_brk &&
		    vma->vm_end <= vma->vm_mm->brk) {
D
David Howells 已提交
3169
			rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3170 3171 3172
		} else if (!vma->vm_file &&
			   vma->vm_start <= vma->vm_mm->start_stack &&
			   vma->vm_end >= vma->vm_mm->start_stack) {
3173
			rc = current_has_perm(current, PROCESS__EXECSTACK);
3174 3175 3176 3177 3178 3179 3180 3181
		} 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
3182
			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3183
		}
3184 3185 3186
		if (rc)
			return rc;
	}
L
Linus Torvalds 已提交
3187 3188 3189 3190 3191 3192

	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)
{
3193 3194 3195
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, FILE__LOCK);
L
Linus Torvalds 已提交
3196 3197 3198 3199 3200
}

static int selinux_file_fcntl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3201
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3202 3203 3204
	int err = 0;

	switch (cmd) {
3205 3206
	case F_SETFL:
		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3207
			err = file_has_perm(cred, file, FILE__WRITE);
L
Linus Torvalds 已提交
3208
			break;
3209 3210 3211 3212 3213 3214 3215
		}
		/* fall through */
	case F_SETOWN:
	case F_SETSIG:
	case F_GETFL:
	case F_GETOWN:
	case F_GETSIG:
3216
	case F_GETOWNER_UIDS:
3217
		/* Just check FD__USE permission */
3218
		err = file_has_perm(cred, file, 0);
3219 3220 3221 3222
		break;
	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
L
Linus Torvalds 已提交
3223
#if BITS_PER_LONG == 32
3224 3225 3226
	case F_GETLK64:
	case F_SETLK64:
	case F_SETLKW64:
L
Linus Torvalds 已提交
3227
#endif
3228
		err = file_has_perm(cred, file, FILE__LOCK);
3229
		break;
L
Linus Torvalds 已提交
3230 3231 3232 3233 3234 3235 3236 3237 3238 3239
	}

	return err;
}

static int selinux_file_set_fowner(struct file *file)
{
	struct file_security_struct *fsec;

	fsec = file->f_security;
3240
	fsec->fown_sid = current_sid();
L
Linus Torvalds 已提交
3241 3242 3243 3244 3245 3246 3247

	return 0;
}

static int selinux_file_send_sigiotask(struct task_struct *tsk,
				       struct fown_struct *fown, int signum)
{
3248
	struct file *file;
3249
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
3250 3251 3252 3253
	u32 perm;
	struct file_security_struct *fsec;

	/* struct fown_struct is never outside the context of a struct file */
3254
	file = container_of(fown, struct file, f_owner);
L
Linus Torvalds 已提交
3255 3256 3257 3258 3259 3260 3261 3262

	fsec = file->f_security;

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

3263
	return avc_has_perm(fsec->fown_sid, sid,
L
Linus Torvalds 已提交
3264 3265 3266 3267 3268
			    SECCLASS_PROCESS, perm, NULL);
}

static int selinux_file_receive(struct file *file)
{
3269 3270 3271
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, file_to_av(file));
L
Linus Torvalds 已提交
3272 3273
}

3274
static int selinux_file_open(struct file *file, const struct cred *cred)
3275 3276 3277
{
	struct file_security_struct *fsec;
	struct inode_security_struct *isec;
D
David Howells 已提交
3278

3279
	fsec = file->f_security;
A
Al Viro 已提交
3280
	isec = file_inode(file)->i_security;
3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297
	/*
	 * 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.
	 */
3298
	return path_has_perm(cred, &file->f_path, open_file_to_av(file));
3299 3300
}

L
Linus Torvalds 已提交
3301 3302 3303 3304
/* task security operations */

static int selinux_task_create(unsigned long clone_flags)
{
3305
	return current_has_perm(current, PROCESS__FORK);
L
Linus Torvalds 已提交
3306 3307
}

3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322
/*
 * 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
3323 3324 3325 3326
/*
 * 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
3327
{
D
David Howells 已提交
3328
	struct task_security_struct *tsec = cred->security;
3329

3330 3331 3332 3333 3334
	/*
	 * 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);
3335
	cred->security = (void *) 0x7UL;
D
David Howells 已提交
3336 3337
	kfree(tsec);
}
L
Linus Torvalds 已提交
3338

D
David Howells 已提交
3339 3340 3341 3342 3343 3344 3345 3346
/*
 * 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
3347

D
David Howells 已提交
3348
	old_tsec = old->security;
L
Linus Torvalds 已提交
3349

D
David Howells 已提交
3350 3351 3352
	tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
	if (!tsec)
		return -ENOMEM;
L
Linus Torvalds 已提交
3353

D
David Howells 已提交
3354
	new->security = tsec;
L
Linus Torvalds 已提交
3355 3356 3357
	return 0;
}

3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368
/*
 * 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;
}

3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409
/*
 * 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)
{
	struct inode_security_struct *isec = inode->i_security;
	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;
3410
	return ret;
3411 3412
}

3413
static int selinux_kernel_module_request(char *kmod_name)
3414
{
3415 3416 3417 3418 3419
	u32 sid;
	struct common_audit_data ad;

	sid = task_sid(current);

3420
	ad.type = LSM_AUDIT_DATA_KMOD;
3421 3422 3423 3424
	ad.u.kmod_name = kmod_name;

	return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
			    SYSTEM__MODULE_REQUEST, &ad);
3425 3426
}

L
Linus Torvalds 已提交
3427 3428
static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
{
3429
	return current_has_perm(p, PROCESS__SETPGID);
L
Linus Torvalds 已提交
3430 3431 3432 3433
}

static int selinux_task_getpgid(struct task_struct *p)
{
3434
	return current_has_perm(p, PROCESS__GETPGID);
L
Linus Torvalds 已提交
3435 3436 3437 3438
}

static int selinux_task_getsid(struct task_struct *p)
{
3439
	return current_has_perm(p, PROCESS__GETSESSION);
L
Linus Torvalds 已提交
3440 3441
}

3442 3443
static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
{
3444
	*secid = task_sid(p);
3445 3446
}

L
Linus Torvalds 已提交
3447 3448 3449 3450
static int selinux_task_setnice(struct task_struct *p, int nice)
{
	int rc;

3451
	rc = cap_task_setnice(p, nice);
L
Linus Torvalds 已提交
3452 3453 3454
	if (rc)
		return rc;

3455
	return current_has_perm(p, PROCESS__SETSCHED);
L
Linus Torvalds 已提交
3456 3457
}

3458 3459
static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
3460 3461
	int rc;

3462
	rc = cap_task_setioprio(p, ioprio);
3463 3464 3465
	if (rc)
		return rc;

3466
	return current_has_perm(p, PROCESS__SETSCHED);
3467 3468
}

3469 3470
static int selinux_task_getioprio(struct task_struct *p)
{
3471
	return current_has_perm(p, PROCESS__GETSCHED);
3472 3473
}

3474 3475
static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
		struct rlimit *new_rlim)
L
Linus Torvalds 已提交
3476
{
3477
	struct rlimit *old_rlim = p->signal->rlim + resource;
L
Linus Torvalds 已提交
3478 3479 3480 3481

	/* 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
3482
	   upon context transitions.  See selinux_bprm_committing_creds. */
L
Linus Torvalds 已提交
3483
	if (old_rlim->rlim_max != new_rlim->rlim_max)
3484
		return current_has_perm(p, PROCESS__SETRLIMIT);
L
Linus Torvalds 已提交
3485 3486 3487 3488

	return 0;
}

3489
static int selinux_task_setscheduler(struct task_struct *p)
L
Linus Torvalds 已提交
3490
{
3491 3492
	int rc;

3493
	rc = cap_task_setscheduler(p);
3494 3495 3496
	if (rc)
		return rc;

3497
	return current_has_perm(p, PROCESS__SETSCHED);
L
Linus Torvalds 已提交
3498 3499 3500 3501
}

static int selinux_task_getscheduler(struct task_struct *p)
{
3502
	return current_has_perm(p, PROCESS__GETSCHED);
L
Linus Torvalds 已提交
3503 3504
}

3505 3506
static int selinux_task_movememory(struct task_struct *p)
{
3507
	return current_has_perm(p, PROCESS__SETSCHED);
3508 3509
}

3510 3511
static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
				int sig, u32 secid)
L
Linus Torvalds 已提交
3512 3513 3514 3515 3516 3517 3518 3519
{
	u32 perm;
	int rc;

	if (!sig)
		perm = PROCESS__SIGNULL; /* null signal; existence test */
	else
		perm = signal_to_av(sig);
3520
	if (secid)
3521 3522
		rc = avc_has_perm(secid, task_sid(p),
				  SECCLASS_PROCESS, perm, NULL);
3523
	else
3524
		rc = current_has_perm(p, perm);
3525
	return rc;
L
Linus Torvalds 已提交
3526 3527 3528 3529
}

static int selinux_task_wait(struct task_struct *p)
{
3530
	return task_has_perm(p, current, PROCESS__SIGCHLD);
L
Linus Torvalds 已提交
3531 3532 3533 3534 3535 3536
}

static void selinux_task_to_inode(struct task_struct *p,
				  struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
3537
	u32 sid = task_sid(p);
L
Linus Torvalds 已提交
3538

3539
	isec->sid = sid;
L
Linus Torvalds 已提交
3540 3541 3542 3543
	isec->initialized = 1;
}

/* Returns error only if unable to parse addresses */
3544
static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3545
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
3546 3547 3548 3549
{
	int offset, ihlen, ret = -EINVAL;
	struct iphdr _iph, *ih;

3550
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
3551 3552 3553 3554 3555 3556 3557 3558
	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
	if (ih == NULL)
		goto out;

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

3559 3560
	ad->u.net->v4info.saddr = ih->saddr;
	ad->u.net->v4info.daddr = ih->daddr;
L
Linus Torvalds 已提交
3561 3562
	ret = 0;

3563 3564 3565
	if (proto)
		*proto = ih->protocol;

L
Linus Torvalds 已提交
3566
	switch (ih->protocol) {
3567 3568
	case IPPROTO_TCP: {
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
3569

3570 3571
		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;
L
Linus Torvalds 已提交
3572 3573 3574 3575 3576 3577

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

3578 3579
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
3580
		break;
3581 3582 3583 3584 3585 3586 3587 3588
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

L
Linus Torvalds 已提交
3589
		offset += ihlen;
3590
		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
L
Linus Torvalds 已提交
3591
		if (uh == NULL)
3592
			break;
L
Linus Torvalds 已提交
3593

3594 3595
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
3596 3597
		break;
	}
L
Linus Torvalds 已提交
3598

J
James Morris 已提交
3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609
	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;

3610 3611
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
3612
		break;
3613
	}
J
James Morris 已提交
3614

3615 3616 3617
	default:
		break;
	}
L
Linus Torvalds 已提交
3618 3619 3620 3621 3622 3623 3624
out:
	return ret;
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

/* Returns error only if unable to parse addresses */
3625
static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3626
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
3627 3628 3629 3630
{
	u8 nexthdr;
	int ret = -EINVAL, offset;
	struct ipv6hdr _ipv6h, *ip6;
3631
	__be16 frag_off;
L
Linus Torvalds 已提交
3632

3633
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
3634 3635 3636 3637
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		goto out;

3638 3639
	ad->u.net->v6info.saddr = ip6->saddr;
	ad->u.net->v6info.daddr = ip6->daddr;
L
Linus Torvalds 已提交
3640 3641 3642 3643
	ret = 0;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
3644
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
L
Linus Torvalds 已提交
3645 3646 3647
	if (offset < 0)
		goto out;

3648 3649 3650
	if (proto)
		*proto = nexthdr;

L
Linus Torvalds 已提交
3651 3652
	switch (nexthdr) {
	case IPPROTO_TCP: {
3653
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
3654 3655 3656 3657 3658

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

3659 3660
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
3661 3662 3663 3664 3665 3666 3667 3668 3669 3670
		break;
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

3671 3672
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
L
Linus Torvalds 已提交
3673 3674 3675
		break;
	}

J
James Morris 已提交
3676 3677 3678 3679 3680 3681 3682
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

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

3683 3684
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
3685
		break;
3686
	}
J
James Morris 已提交
3687

L
Linus Torvalds 已提交
3688 3689 3690 3691 3692 3693 3694 3695 3696 3697
	/* includes fragments */
	default:
		break;
	}
out:
	return ret;
}

#endif /* IPV6 */

3698
static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3699
			     char **_addrp, int src, u8 *proto)
L
Linus Torvalds 已提交
3700
{
3701 3702
	char *addrp;
	int ret;
L
Linus Torvalds 已提交
3703

3704
	switch (ad->u.net->family) {
L
Linus Torvalds 已提交
3705
	case PF_INET:
3706
		ret = selinux_parse_skb_ipv4(skb, ad, proto);
3707 3708
		if (ret)
			goto parse_error;
3709 3710
		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
				       &ad->u.net->v4info.daddr);
3711
		goto okay;
L
Linus Torvalds 已提交
3712 3713 3714

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	case PF_INET6:
3715
		ret = selinux_parse_skb_ipv6(skb, ad, proto);
3716 3717
		if (ret)
			goto parse_error;
3718 3719
		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
				       &ad->u.net->v6info.daddr);
3720
		goto okay;
L
Linus Torvalds 已提交
3721 3722
#endif	/* IPV6 */
	default:
3723 3724
		addrp = NULL;
		goto okay;
L
Linus Torvalds 已提交
3725 3726
	}

3727 3728 3729 3730
parse_error:
	printk(KERN_WARNING
	       "SELinux: failure in selinux_parse_skb(),"
	       " unable to parse packet\n");
L
Linus Torvalds 已提交
3731
	return ret;
3732 3733 3734 3735 3736

okay:
	if (_addrp)
		*_addrp = addrp;
	return 0;
L
Linus Torvalds 已提交
3737 3738
}

3739
/**
3740
 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3741
 * @skb: the packet
3742
 * @family: protocol family
3743
 * @sid: the packet's peer label SID
3744 3745
 *
 * Description:
3746 3747 3748 3749 3750 3751
 * 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.
3752 3753
 *
 */
3754
static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3755
{
3756
	int err;
3757 3758
	u32 xfrm_sid;
	u32 nlbl_sid;
3759
	u32 nlbl_type;
3760

3761 3762 3763 3764 3765 3766
	err = selinux_skb_xfrm_sid(skb, &xfrm_sid);
	if (unlikely(err))
		return -EACCES;
	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
	if (unlikely(err))
		return -EACCES;
3767

3768 3769 3770 3771 3772
	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");
3773
		return -EACCES;
3774
	}
3775 3776

	return 0;
3777 3778
}

L
Linus Torvalds 已提交
3779
/* socket security operations */
3780

3781 3782
static int socket_sockcreate_sid(const struct task_security_struct *tsec,
				 u16 secclass, u32 *socksid)
3783
{
3784 3785 3786 3787 3788 3789 3790
	if (tsec->sockcreate_sid > SECSID_NULL) {
		*socksid = tsec->sockcreate_sid;
		return 0;
	}

	return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
				       socksid);
3791 3792
}

3793
static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
L
Linus Torvalds 已提交
3794
{
3795
	struct sk_security_struct *sksec = sk->sk_security;
3796
	struct common_audit_data ad;
3797
	struct lsm_network_audit net = {0,};
3798
	u32 tsid = task_sid(task);
L
Linus Torvalds 已提交
3799

3800 3801
	if (sksec->sid == SECINITSID_KERNEL)
		return 0;
L
Linus Torvalds 已提交
3802

3803
	ad.type = LSM_AUDIT_DATA_NET;
3804 3805
	ad.u.net = &net;
	ad.u.net->sk = sk;
L
Linus Torvalds 已提交
3806

3807
	return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
L
Linus Torvalds 已提交
3808 3809 3810 3811 3812
}

static int selinux_socket_create(int family, int type,
				 int protocol, int kern)
{
3813
	const struct task_security_struct *tsec = current_security();
3814
	u32 newsid;
3815
	u16 secclass;
3816
	int rc;
L
Linus Torvalds 已提交
3817 3818

	if (kern)
3819
		return 0;
3820 3821

	secclass = socket_type_to_security_class(family, type, protocol);
3822 3823 3824 3825
	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
	if (rc)
		return rc;

3826
	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
L
Linus Torvalds 已提交
3827 3828
}

V
Venkat Yekkirala 已提交
3829 3830
static int selinux_socket_post_create(struct socket *sock, int family,
				      int type, int protocol, int kern)
L
Linus Torvalds 已提交
3831
{
3832
	const struct task_security_struct *tsec = current_security();
3833
	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3834
	struct sk_security_struct *sksec;
3835 3836
	int err = 0;

3837 3838
	isec->sclass = socket_type_to_security_class(family, type, protocol);

3839 3840
	if (kern)
		isec->sid = SECINITSID_KERNEL;
3841 3842 3843 3844 3845
	else {
		err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
		if (err)
			return err;
	}
3846

L
Linus Torvalds 已提交
3847 3848
	isec->initialized = 1;

3849 3850 3851
	if (sock->sk) {
		sksec = sock->sk->sk_security;
		sksec->sid = isec->sid;
3852
		sksec->sclass = isec->sclass;
3853
		err = selinux_netlbl_socket_post_create(sock->sk, family);
3854 3855
	}

V
Venkat Yekkirala 已提交
3856
	return err;
L
Linus Torvalds 已提交
3857 3858 3859 3860 3861 3862 3863 3864
}

/* 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)
{
3865
	struct sock *sk = sock->sk;
L
Linus Torvalds 已提交
3866 3867 3868
	u16 family;
	int err;

3869
	err = sock_has_perm(current, sk, SOCKET__BIND);
L
Linus Torvalds 已提交
3870 3871 3872 3873 3874
	if (err)
		goto out;

	/*
	 * If PF_INET or PF_INET6, check name_bind permission for the port.
3875 3876
	 * Multiple address binding for SCTP is not supported yet: we just
	 * check the first address now.
L
Linus Torvalds 已提交
3877
	 */
3878
	family = sk->sk_family;
L
Linus Torvalds 已提交
3879 3880
	if (family == PF_INET || family == PF_INET6) {
		char *addrp;
3881
		struct sk_security_struct *sksec = sk->sk_security;
3882
		struct common_audit_data ad;
3883
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
3884 3885 3886
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
3887
		u32 sid, node_perm;
L
Linus Torvalds 已提交
3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898

		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;
		}

3899 3900 3901 3902 3903 3904
		if (snum) {
			int low, high;

			inet_get_local_port_range(&low, &high);

			if (snum < max(PROT_SOCK, low) || snum > high) {
P
Paul Moore 已提交
3905 3906
				err = sel_netport_sid(sk->sk_protocol,
						      snum, &sid);
3907 3908
				if (err)
					goto out;
3909
				ad.type = LSM_AUDIT_DATA_NET;
3910 3911 3912
				ad.u.net = &net;
				ad.u.net->sport = htons(snum);
				ad.u.net->family = family;
3913 3914
				err = avc_has_perm(sksec->sid, sid,
						   sksec->sclass,
3915 3916 3917 3918
						   SOCKET__NAME_BIND, &ad);
				if (err)
					goto out;
			}
L
Linus Torvalds 已提交
3919
		}
3920

3921
		switch (sksec->sclass) {
3922
		case SECCLASS_TCP_SOCKET:
L
Linus Torvalds 已提交
3923 3924
			node_perm = TCP_SOCKET__NODE_BIND;
			break;
3925

3926
		case SECCLASS_UDP_SOCKET:
L
Linus Torvalds 已提交
3927 3928
			node_perm = UDP_SOCKET__NODE_BIND;
			break;
J
James Morris 已提交
3929 3930 3931 3932 3933

		case SECCLASS_DCCP_SOCKET:
			node_perm = DCCP_SOCKET__NODE_BIND;
			break;

L
Linus Torvalds 已提交
3934 3935 3936 3937
		default:
			node_perm = RAWIP_SOCKET__NODE_BIND;
			break;
		}
3938

3939
		err = sel_netnode_sid(addrp, family, &sid);
L
Linus Torvalds 已提交
3940 3941
		if (err)
			goto out;
3942

3943
		ad.type = LSM_AUDIT_DATA_NET;
3944 3945 3946
		ad.u.net = &net;
		ad.u.net->sport = htons(snum);
		ad.u.net->family = family;
L
Linus Torvalds 已提交
3947 3948

		if (family == PF_INET)
3949
			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
L
Linus Torvalds 已提交
3950
		else
3951
			ad.u.net->v6info.saddr = addr6->sin6_addr;
L
Linus Torvalds 已提交
3952

3953 3954
		err = avc_has_perm(sksec->sid, sid,
				   sksec->sclass, node_perm, &ad);
L
Linus Torvalds 已提交
3955 3956 3957 3958 3959 3960 3961 3962 3963
		if (err)
			goto out;
	}
out:
	return err;
}

static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
{
3964
	struct sock *sk = sock->sk;
3965
	struct sk_security_struct *sksec = sk->sk_security;
L
Linus Torvalds 已提交
3966 3967
	int err;

3968
	err = sock_has_perm(current, sk, SOCKET__CONNECT);
L
Linus Torvalds 已提交
3969 3970 3971 3972
	if (err)
		return err;

	/*
J
James Morris 已提交
3973
	 * If a TCP or DCCP socket, check name_connect permission for the port.
L
Linus Torvalds 已提交
3974
	 */
3975 3976
	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
3977
		struct common_audit_data ad;
3978
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
3979 3980 3981
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
J
James Morris 已提交
3982
		u32 sid, perm;
L
Linus Torvalds 已提交
3983 3984 3985

		if (sk->sk_family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
3986
			if (addrlen < sizeof(struct sockaddr_in))
L
Linus Torvalds 已提交
3987 3988 3989 3990
				return -EINVAL;
			snum = ntohs(addr4->sin_port);
		} else {
			addr6 = (struct sockaddr_in6 *)address;
3991
			if (addrlen < SIN6_LEN_RFC2133)
L
Linus Torvalds 已提交
3992 3993 3994 3995
				return -EINVAL;
			snum = ntohs(addr6->sin6_port);
		}

P
Paul Moore 已提交
3996
		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
L
Linus Torvalds 已提交
3997 3998 3999
		if (err)
			goto out;

4000
		perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
J
James Morris 已提交
4001 4002
		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;

4003
		ad.type = LSM_AUDIT_DATA_NET;
4004 4005 4006
		ad.u.net = &net;
		ad.u.net->dport = htons(snum);
		ad.u.net->family = sk->sk_family;
4007
		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
L
Linus Torvalds 已提交
4008 4009 4010 4011
		if (err)
			goto out;
	}

4012 4013
	err = selinux_netlbl_socket_connect(sk, address);

L
Linus Torvalds 已提交
4014 4015 4016 4017 4018 4019
out:
	return err;
}

static int selinux_socket_listen(struct socket *sock, int backlog)
{
4020
	return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
L
Linus Torvalds 已提交
4021 4022 4023 4024 4025 4026 4027 4028
}

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

4029
	err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
L
Linus Torvalds 已提交
4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043
	if (err)
		return err;

	newisec = SOCK_INODE(newsock)->i_security;

	isec = SOCK_INODE(sock)->i_security;
	newisec->sclass = isec->sclass;
	newisec->sid = isec->sid;
	newisec->initialized = 1;

	return 0;
}

static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4044
				  int size)
L
Linus Torvalds 已提交
4045
{
4046
	return sock_has_perm(current, sock->sk, SOCKET__WRITE);
L
Linus Torvalds 已提交
4047 4048 4049 4050 4051
}

static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
				  int size, int flags)
{
4052
	return sock_has_perm(current, sock->sk, SOCKET__READ);
L
Linus Torvalds 已提交
4053 4054 4055 4056
}

static int selinux_socket_getsockname(struct socket *sock)
{
4057
	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4058 4059 4060 4061
}

static int selinux_socket_getpeername(struct socket *sock)
{
4062
	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4063 4064
}

4065
static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
L
Linus Torvalds 已提交
4066
{
4067 4068
	int err;

4069
	err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4070 4071 4072 4073
	if (err)
		return err;

	return selinux_netlbl_socket_setsockopt(sock, level, optname);
L
Linus Torvalds 已提交
4074 4075 4076 4077 4078
}

static int selinux_socket_getsockopt(struct socket *sock, int level,
				     int optname)
{
4079
	return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
L
Linus Torvalds 已提交
4080 4081 4082 4083
}

static int selinux_socket_shutdown(struct socket *sock, int how)
{
4084
	return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
L
Linus Torvalds 已提交
4085 4086
}

4087 4088
static int selinux_socket_unix_stream_connect(struct sock *sock,
					      struct sock *other,
L
Linus Torvalds 已提交
4089 4090
					      struct sock *newsk)
{
4091 4092
	struct sk_security_struct *sksec_sock = sock->sk_security;
	struct sk_security_struct *sksec_other = other->sk_security;
4093
	struct sk_security_struct *sksec_new = newsk->sk_security;
4094
	struct common_audit_data ad;
4095
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4096 4097
	int err;

4098
	ad.type = LSM_AUDIT_DATA_NET;
4099 4100
	ad.u.net = &net;
	ad.u.net->sk = other;
L
Linus Torvalds 已提交
4101

4102 4103
	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
			   sksec_other->sclass,
L
Linus Torvalds 已提交
4104 4105 4106 4107 4108
			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
	if (err)
		return err;

	/* server child socket */
4109 4110 4111 4112 4113
	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;
4114

4115 4116 4117 4118
	/* connecting socket */
	sksec_sock->peer_sid = sksec_new->sid;

	return 0;
L
Linus Torvalds 已提交
4119 4120 4121 4122 4123
}

static int selinux_socket_unix_may_send(struct socket *sock,
					struct socket *other)
{
4124 4125
	struct sk_security_struct *ssec = sock->sk->sk_security;
	struct sk_security_struct *osec = other->sk->sk_security;
4126
	struct common_audit_data ad;
4127
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4128

4129
	ad.type = LSM_AUDIT_DATA_NET;
4130 4131
	ad.u.net = &net;
	ad.u.net->sk = other->sk;
L
Linus Torvalds 已提交
4132

4133 4134
	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
			    &ad);
L
Linus Torvalds 已提交
4135 4136
}

4137 4138
static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
				    u32 peer_sid,
4139
				    struct common_audit_data *ad)
4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159
{
	int err;
	u32 if_sid;
	u32 node_sid;

	err = sel_netif_sid(ifindex, &if_sid);
	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);
}

4160
static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4161
				       u16 family)
4162
{
4163
	int err = 0;
4164 4165
	struct sk_security_struct *sksec = sk->sk_security;
	u32 sk_sid = sksec->sid;
4166
	struct common_audit_data ad;
4167
	struct lsm_network_audit net = {0,};
4168 4169
	char *addrp;

4170
	ad.type = LSM_AUDIT_DATA_NET;
4171 4172 4173
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4174 4175 4176
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
	if (err)
		return err;
L
Linus Torvalds 已提交
4177

4178
	if (selinux_secmark_enabled()) {
4179
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4180
				   PACKET__RECV, &ad);
4181 4182 4183
		if (err)
			return err;
	}
4184

4185 4186 4187 4188
	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
	if (err)
		return err;
	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4189

4190 4191 4192 4193 4194
	return err;
}

static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
4195
	int err;
4196
	struct sk_security_struct *sksec = sk->sk_security;
4197 4198
	u16 family = sk->sk_family;
	u32 sk_sid = sksec->sid;
4199
	struct common_audit_data ad;
4200
	struct lsm_network_audit net = {0,};
4201
	char *addrp;
4202 4203
	u8 secmark_active;
	u8 peerlbl_active;
4204 4205

	if (family != PF_INET && family != PF_INET6)
4206
		return 0;
4207 4208

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
A
Al Viro 已提交
4209
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4210 4211
		family = PF_INET;

4212 4213 4214 4215
	/* 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. */
4216
	if (!selinux_policycap_netpeer)
4217 4218 4219
		return selinux_sock_rcv_skb_compat(sk, skb, family);

	secmark_active = selinux_secmark_enabled();
4220
	peerlbl_active = selinux_peerlbl_enabled();
4221 4222 4223
	if (!secmark_active && !peerlbl_active)
		return 0;

4224
	ad.type = LSM_AUDIT_DATA_NET;
4225 4226 4227
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4228
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4229
	if (err)
4230
		return err;
4231

4232
	if (peerlbl_active) {
4233 4234 4235
		u32 peer_sid;

		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4236 4237
		if (err)
			return err;
4238
		err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4239
					       peer_sid, &ad);
4240 4241
		if (err) {
			selinux_netlbl_err(skb, err, 0);
4242
			return err;
4243
		}
4244 4245
		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
				   PEER__RECV, &ad);
4246 4247
		if (err)
			selinux_netlbl_err(skb, err, 0);
4248 4249
	}

4250
	if (secmark_active) {
4251 4252 4253 4254 4255 4256
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
				   PACKET__RECV, &ad);
		if (err)
			return err;
	}

4257
	return err;
L
Linus Torvalds 已提交
4258 4259
}

C
Catherine Zhang 已提交
4260 4261
static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
					    int __user *optlen, unsigned len)
L
Linus Torvalds 已提交
4262 4263 4264 4265
{
	int err = 0;
	char *scontext;
	u32 scontext_len;
4266
	struct sk_security_struct *sksec = sock->sk->sk_security;
4267
	u32 peer_sid = SECSID_NULL;
L
Linus Torvalds 已提交
4268

4269 4270
	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
	    sksec->sclass == SECCLASS_TCP_SOCKET)
4271
		peer_sid = sksec->peer_sid;
4272 4273
	if (peer_sid == SECSID_NULL)
		return -ENOPROTOOPT;
L
Linus Torvalds 已提交
4274

C
Catherine Zhang 已提交
4275
	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
L
Linus Torvalds 已提交
4276
	if (err)
4277
		return err;
L
Linus Torvalds 已提交
4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293

	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;
}

4294
static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
C
Catherine Zhang 已提交
4295
{
4296
	u32 peer_secid = SECSID_NULL;
4297
	u16 family;
C
Catherine Zhang 已提交
4298

4299 4300 4301 4302 4303
	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)
4304 4305 4306 4307 4308
		family = sock->sk->sk_family;
	else
		goto out;

	if (sock && family == PF_UNIX)
4309
		selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4310
	else if (skb)
4311
		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
C
Catherine Zhang 已提交
4312

4313
out:
4314
	*secid = peer_secid;
4315 4316 4317
	if (peer_secid == SECSID_NULL)
		return -EINVAL;
	return 0;
C
Catherine Zhang 已提交
4318 4319
}

A
Al Viro 已提交
4320
static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
L
Linus Torvalds 已提交
4321
{
4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333
	struct sk_security_struct *sksec;

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

	sksec->peer_sid = SECINITSID_UNLABELED;
	sksec->sid = SECINITSID_UNLABELED;
	selinux_netlbl_sk_security_reset(sksec);
	sk->sk_security = sksec;

	return 0;
L
Linus Torvalds 已提交
4334 4335 4336 4337
}

static void selinux_sk_free_security(struct sock *sk)
{
4338 4339 4340 4341 4342
	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
4343 4344
}

4345
static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4346
{
4347 4348
	struct sk_security_struct *sksec = sk->sk_security;
	struct sk_security_struct *newsksec = newsk->sk_security;
4349

4350 4351 4352
	newsksec->sid = sksec->sid;
	newsksec->peer_sid = sksec->peer_sid;
	newsksec->sclass = sksec->sclass;
4353

4354
	selinux_netlbl_sk_security_reset(newsksec);
4355 4356
}

V
Venkat Yekkirala 已提交
4357
static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4358
{
4359
	if (!sk)
V
Venkat Yekkirala 已提交
4360
		*secid = SECINITSID_ANY_SOCKET;
4361 4362
	else {
		struct sk_security_struct *sksec = sk->sk_security;
4363

V
Venkat Yekkirala 已提交
4364
		*secid = sksec->sid;
4365
	}
4366 4367
}

4368
static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4369 4370 4371 4372
{
	struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
	struct sk_security_struct *sksec = sk->sk_security;

4373 4374 4375
	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
	    sk->sk_family == PF_UNIX)
		isec->sid = sksec->sid;
4376
	sksec->sclass = isec->sclass;
4377 4378
}

4379 4380
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				     struct request_sock *req)
4381 4382 4383
{
	struct sk_security_struct *sksec = sk->sk_security;
	int err;
4384
	u16 family = sk->sk_family;
V
Venkat Yekkirala 已提交
4385
	u32 newsid;
4386 4387
	u32 peersid;

4388 4389 4390 4391 4392
	/* handle mapped IPv4 packets arriving via IPv6 sockets */
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;

	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4393 4394
	if (err)
		return err;
4395 4396
	if (peersid == SECSID_NULL) {
		req->secid = sksec->sid;
4397
		req->peer_secid = SECSID_NULL;
4398 4399 4400 4401 4402 4403
	} else {
		err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
		if (err)
			return err;
		req->secid = newsid;
		req->peer_secid = peersid;
4404 4405
	}

4406
	return selinux_netlbl_inet_conn_request(req, family);
4407 4408
}

4409 4410
static void selinux_inet_csk_clone(struct sock *newsk,
				   const struct request_sock *req)
4411 4412 4413 4414
{
	struct sk_security_struct *newsksec = newsk->sk_security;

	newsksec->sid = req->secid;
4415
	newsksec->peer_sid = req->peer_secid;
4416 4417 4418 4419
	/* 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. */
4420

P
Paul Moore 已提交
4421 4422
	/* We don't need to take any sort of lock here as we are the only
	 * thread with access to newsksec */
4423
	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4424 4425
}

4426
static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4427
{
4428
	u16 family = sk->sk_family;
4429 4430
	struct sk_security_struct *sksec = sk->sk_security;

4431 4432 4433 4434 4435
	/* 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);
4436 4437
}

4438 4439 4440 4441 4442
static void selinux_skb_owned_by(struct sk_buff *skb, struct sock *sk)
{
	skb_set_owner_w(skb, sk);
}

4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463
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);
}

4464 4465
static void selinux_req_classify_flow(const struct request_sock *req,
				      struct flowi *fl)
4466
{
4467
	fl->flowi_secid = req->secid;
4468 4469
}

4470 4471 4472 4473 4474 4475 4476 4477 4478 4479 4480 4481 4482 4483 4484 4485 4486 4487
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);
}

4488 4489 4490 4491 4492 4493 4494 4495 4496 4497 4498 4499 4500 4501 4502
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);
}

4503
static int selinux_tun_dev_attach_queue(void *security)
4504
{
4505 4506 4507 4508 4509 4510 4511 4512 4513
	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;
4514 4515 4516 4517 4518 4519 4520 4521 4522
	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 */

4523
	sksec->sid = tunsec->sid;
4524
	sksec->sclass = SECCLASS_TUN_SOCKET;
4525 4526

	return 0;
4527 4528
}

4529
static int selinux_tun_dev_open(void *security)
4530
{
4531
	struct tun_security_struct *tunsec = security;
4532 4533 4534
	u32 sid = current_sid();
	int err;

4535
	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
4536 4537 4538 4539 4540 4541 4542
			   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;
4543
	tunsec->sid = sid;
4544 4545 4546 4547

	return 0;
}

L
Linus Torvalds 已提交
4548 4549 4550 4551 4552
static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
{
	int err = 0;
	u32 perm;
	struct nlmsghdr *nlh;
4553
	struct sk_security_struct *sksec = sk->sk_security;
4554

4555
	if (skb->len < NLMSG_HDRLEN) {
L
Linus Torvalds 已提交
4556 4557 4558
		err = -EINVAL;
		goto out;
	}
4559
	nlh = nlmsg_hdr(skb);
4560

4561
	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
L
Linus Torvalds 已提交
4562 4563
	if (err) {
		if (err == -EINVAL) {
4564
			audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
L
Linus Torvalds 已提交
4565 4566
				  "SELinux:  unrecognized netlink message"
				  " type=%hu for sclass=%hu\n",
4567
				  nlh->nlmsg_type, sksec->sclass);
4568
			if (!selinux_enforcing || security_get_allow_unknown())
L
Linus Torvalds 已提交
4569 4570 4571 4572 4573 4574 4575 4576 4577
				err = 0;
		}

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

4578
	err = sock_has_perm(current, sk, perm);
L
Linus Torvalds 已提交
4579 4580 4581 4582 4583 4584
out:
	return err;
}

#ifdef CONFIG_NETFILTER

4585 4586
static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
				       u16 family)
L
Linus Torvalds 已提交
4587
{
4588
	int err;
4589 4590
	char *addrp;
	u32 peer_sid;
4591
	struct common_audit_data ad;
4592
	struct lsm_network_audit net = {0,};
4593
	u8 secmark_active;
4594
	u8 netlbl_active;
4595
	u8 peerlbl_active;
4596

4597 4598
	if (!selinux_policycap_netpeer)
		return NF_ACCEPT;
4599

4600
	secmark_active = selinux_secmark_enabled();
4601
	netlbl_active = netlbl_enabled();
4602
	peerlbl_active = selinux_peerlbl_enabled();
4603 4604
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;
4605

4606 4607 4608
	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
		return NF_DROP;

4609
	ad.type = LSM_AUDIT_DATA_NET;
4610 4611 4612
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4613 4614 4615
	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
		return NF_DROP;

4616 4617 4618 4619 4620
	if (peerlbl_active) {
		err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
					       peer_sid, &ad);
		if (err) {
			selinux_netlbl_err(skb, err, 1);
4621
			return NF_DROP;
4622 4623
		}
	}
4624 4625 4626 4627 4628 4629

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

4630 4631 4632 4633 4634 4635 4636 4637
	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;

4638 4639 4640 4641 4642 4643 4644 4645 4646 4647 4648 4649 4650 4651 4652 4653 4654 4655 4656 4657 4658 4659 4660
	return NF_ACCEPT;
}

static unsigned int selinux_ipv4_forward(unsigned int hooknum,
					 struct sk_buff *skb,
					 const struct net_device *in,
					 const struct net_device *out,
					 int (*okfn)(struct sk_buff *))
{
	return selinux_ip_forward(skb, in->ifindex, PF_INET);
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
static unsigned int selinux_ipv6_forward(unsigned int hooknum,
					 struct sk_buff *skb,
					 const struct net_device *in,
					 const struct net_device *out,
					 int (*okfn)(struct sk_buff *))
{
	return selinux_ip_forward(skb, in->ifindex, PF_INET6);
}
#endif	/* IPV6 */

4661 4662 4663 4664 4665 4666 4667 4668 4669 4670 4671 4672 4673 4674 4675 4676 4677 4678 4679 4680 4681 4682 4683 4684 4685 4686 4687 4688 4689 4690 4691
static unsigned int selinux_ip_output(struct sk_buff *skb,
				      u16 family)
{
	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 */
	if (skb->sk) {
		struct sk_security_struct *sksec = skb->sk->sk_security;
		sid = sksec->sid;
	} else
		sid = SECINITSID_KERNEL;
	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
		return NF_DROP;

	return NF_ACCEPT;
}

static unsigned int selinux_ipv4_output(unsigned int hooknum,
					struct sk_buff *skb,
					const struct net_device *in,
					const struct net_device *out,
					int (*okfn)(struct sk_buff *))
{
	return selinux_ip_output(skb, PF_INET);
}

4692 4693
static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
						int ifindex,
4694
						u16 family)
4695 4696 4697
{
	struct sock *sk = skb->sk;
	struct sk_security_struct *sksec;
4698
	struct common_audit_data ad;
4699
	struct lsm_network_audit net = {0,};
4700 4701
	char *addrp;
	u8 proto;
L
Linus Torvalds 已提交
4702

4703 4704 4705 4706
	if (sk == NULL)
		return NF_ACCEPT;
	sksec = sk->sk_security;

4707
	ad.type = LSM_AUDIT_DATA_NET;
4708 4709 4710
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4711 4712 4713
	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
		return NF_DROP;

4714
	if (selinux_secmark_enabled())
4715
		if (avc_has_perm(sksec->sid, skb->secmark,
4716
				 SECCLASS_PACKET, PACKET__SEND, &ad))
4717
			return NF_DROP_ERR(-ECONNREFUSED);
4718

4719 4720
	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
		return NF_DROP_ERR(-ECONNREFUSED);
4721 4722

	return NF_ACCEPT;
4723 4724
}

4725 4726
static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
					 u16 family)
4727
{
4728 4729
	u32 secmark_perm;
	u32 peer_sid;
4730
	struct sock *sk;
4731
	struct common_audit_data ad;
4732
	struct lsm_network_audit net = {0,};
4733 4734 4735
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;
4736

4737 4738 4739 4740
	/* 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. */
4741
	if (!selinux_policycap_netpeer)
4742
		return selinux_ip_postroute_compat(skb, ifindex, family);
4743
#ifdef CONFIG_XFRM
4744 4745 4746 4747 4748 4749
	/* 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
	 *       is NULL, in this case go ahead and apply access control. */
E
Eric Dumazet 已提交
4750
	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4751
		return NF_ACCEPT;
4752
#endif
4753
	secmark_active = selinux_secmark_enabled();
4754
	peerlbl_active = selinux_peerlbl_enabled();
4755 4756 4757
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;

4758 4759 4760 4761
	/* if the packet is being forwarded then get the peer label from the
	 * packet itself; otherwise check to see if it is from a local
	 * application or the kernel, if from an application get the peer label
	 * from the sending socket, otherwise use the kernel's sid */
4762
	sk = skb->sk;
4763
	if (sk == NULL) {
4764 4765
		if (skb->skb_iif) {
			secmark_perm = PACKET__FORWARD_OUT;
4766
			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4767
				return NF_DROP;
4768 4769
		} else {
			secmark_perm = PACKET__SEND;
4770
			peer_sid = SECINITSID_KERNEL;
4771
		}
4772
	} else {
4773 4774 4775 4776
		struct sk_security_struct *sksec = sk->sk_security;
		peer_sid = sksec->sid;
		secmark_perm = PACKET__SEND;
	}
4777

4778
	ad.type = LSM_AUDIT_DATA_NET;
4779 4780 4781
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4782
	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4783
		return NF_DROP;
4784

4785 4786 4787
	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, secmark_perm, &ad))
4788
			return NF_DROP_ERR(-ECONNREFUSED);
4789 4790 4791 4792 4793 4794

	if (peerlbl_active) {
		u32 if_sid;
		u32 node_sid;

		if (sel_netif_sid(ifindex, &if_sid))
4795
			return NF_DROP;
4796 4797
		if (avc_has_perm(peer_sid, if_sid,
				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4798
			return NF_DROP_ERR(-ECONNREFUSED);
4799 4800

		if (sel_netnode_sid(addrp, family, &node_sid))
4801
			return NF_DROP;
4802 4803
		if (avc_has_perm(peer_sid, node_sid,
				 SECCLASS_NODE, NODE__SENDTO, &ad))
4804
			return NF_DROP_ERR(-ECONNREFUSED);
4805
	}
4806

4807
	return NF_ACCEPT;
L
Linus Torvalds 已提交
4808 4809
}

4810 4811 4812 4813 4814
static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
					   struct sk_buff *skb,
					   const struct net_device *in,
					   const struct net_device *out,
					   int (*okfn)(struct sk_buff *))
L
Linus Torvalds 已提交
4815
{
4816
	return selinux_ip_postroute(skb, out->ifindex, PF_INET);
L
Linus Torvalds 已提交
4817 4818 4819
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4820 4821 4822 4823 4824
static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
					   struct sk_buff *skb,
					   const struct net_device *in,
					   const struct net_device *out,
					   int (*okfn)(struct sk_buff *))
L
Linus Torvalds 已提交
4825
{
4826
	return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
L
Linus Torvalds 已提交
4827 4828 4829 4830 4831 4832 4833 4834 4835
}
#endif	/* IPV6 */

#endif	/* CONFIG_NETFILTER */

static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
{
	int err;

4836
	err = cap_netlink_send(sk, skb);
L
Linus Torvalds 已提交
4837 4838 4839
	if (err)
		return err;

4840
	return selinux_nlmsg_perm(sk, skb);
L
Linus Torvalds 已提交
4841 4842 4843 4844 4845 4846 4847
}

static int ipc_alloc_security(struct task_struct *task,
			      struct kern_ipc_perm *perm,
			      u16 sclass)
{
	struct ipc_security_struct *isec;
4848
	u32 sid;
L
Linus Torvalds 已提交
4849

J
James Morris 已提交
4850
	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
4851 4852 4853
	if (!isec)
		return -ENOMEM;

4854
	sid = task_sid(task);
L
Linus Torvalds 已提交
4855
	isec->sclass = sclass;
4856
	isec->sid = sid;
L
Linus Torvalds 已提交
4857 4858 4859 4860 4861 4862 4863 4864 4865 4866 4867 4868 4869 4870 4871 4872
	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
4873
	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891
	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,
4892
			u32 perms)
L
Linus Torvalds 已提交
4893 4894
{
	struct ipc_security_struct *isec;
4895
	struct common_audit_data ad;
4896
	u32 sid = current_sid();
L
Linus Torvalds 已提交
4897 4898 4899

	isec = ipc_perms->security;

4900
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
4901 4902
	ad.u.ipc_id = ipc_perms->key;

4903
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
L
Linus Torvalds 已提交
4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919
}

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;
4920
	struct common_audit_data ad;
4921
	u32 sid = current_sid();
L
Linus Torvalds 已提交
4922 4923 4924 4925 4926 4927 4928 4929
	int rc;

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

	isec = msq->q_perm.security;

4930
	ad.type = LSM_AUDIT_DATA_IPC;
4931
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
4932

4933
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949
			  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;
4950
	struct common_audit_data ad;
4951
	u32 sid = current_sid();
L
Linus Torvalds 已提交
4952 4953 4954

	isec = msq->q_perm.security;

4955
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
4956 4957
	ad.u.ipc_id = msq->q_perm.key;

4958
	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
4959 4960 4961 4962 4963 4964 4965 4966
			    MSGQ__ASSOCIATE, &ad);
}

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

4967
	switch (cmd) {
L
Linus Torvalds 已提交
4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983 4984 4985
	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;
	}

4986
	err = ipc_has_perm(&msq->q_perm, perms);
L
Linus Torvalds 已提交
4987 4988 4989 4990 4991 4992 4993
	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;
4994
	struct common_audit_data ad;
4995
	u32 sid = current_sid();
L
Linus Torvalds 已提交
4996 4997 4998 4999 5000 5001 5002 5003 5004 5005 5006 5007 5008
	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
		 */
5009
		rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5010
					     NULL, &msec->sid);
L
Linus Torvalds 已提交
5011 5012 5013 5014
		if (rc)
			return rc;
	}

5015
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5016 5017 5018
	ad.u.ipc_id = msq->q_perm.key;

	/* Can this process write to the queue? */
5019
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5020 5021 5022
			  MSGQ__WRITE, &ad);
	if (!rc)
		/* Can this process send the message */
5023 5024
		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
				  MSG__SEND, &ad);
L
Linus Torvalds 已提交
5025 5026
	if (!rc)
		/* Can the message be put in the queue? */
5027 5028
		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
				  MSGQ__ENQUEUE, &ad);
L
Linus Torvalds 已提交
5029 5030 5031 5032 5033 5034 5035 5036 5037 5038

	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;
5039
	struct common_audit_data ad;
5040
	u32 sid = task_sid(target);
L
Linus Torvalds 已提交
5041 5042 5043 5044 5045
	int rc;

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

5046
	ad.type = LSM_AUDIT_DATA_IPC;
5047
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5048

5049
	rc = avc_has_perm(sid, isec->sid,
L
Linus Torvalds 已提交
5050 5051
			  SECCLASS_MSGQ, MSGQ__READ, &ad);
	if (!rc)
5052
		rc = avc_has_perm(sid, msec->sid,
L
Linus Torvalds 已提交
5053 5054 5055 5056 5057 5058 5059 5060
				  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;
5061
	struct common_audit_data ad;
5062
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5063 5064 5065 5066 5067 5068 5069 5070
	int rc;

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

	isec = shp->shm_perm.security;

5071
	ad.type = LSM_AUDIT_DATA_IPC;
5072
	ad.u.ipc_id = shp->shm_perm.key;
L
Linus Torvalds 已提交
5073

5074
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5075 5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090
			  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;
5091
	struct common_audit_data ad;
5092
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5093 5094 5095

	isec = shp->shm_perm.security;

5096
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5097 5098
	ad.u.ipc_id = shp->shm_perm.key;

5099
	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5100 5101 5102 5103 5104 5105 5106 5107 5108
			    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;

5109
	switch (cmd) {
L
Linus Torvalds 已提交
5110 5111 5112 5113 5114 5115 5116 5117 5118 5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131
	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;
	}

5132
	err = ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5133 5134 5135 5136 5137 5138 5139 5140 5141 5142 5143 5144 5145
	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;

5146
	return ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5147 5148 5149 5150 5151 5152
}

/* Semaphore security operations */
static int selinux_sem_alloc_security(struct sem_array *sma)
{
	struct ipc_security_struct *isec;
5153
	struct common_audit_data ad;
5154
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5155 5156 5157 5158 5159 5160 5161 5162
	int rc;

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

	isec = sma->sem_perm.security;

5163
	ad.type = LSM_AUDIT_DATA_IPC;
5164
	ad.u.ipc_id = sma->sem_perm.key;
L
Linus Torvalds 已提交
5165

5166
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178 5179 5180 5181 5182
			  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;
5183
	struct common_audit_data ad;
5184
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5185 5186 5187

	isec = sma->sem_perm.security;

5188
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5189 5190
	ad.u.ipc_id = sma->sem_perm.key;

5191
	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5192 5193 5194 5195 5196 5197 5198 5199 5200
			    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;

5201
	switch (cmd) {
L
Linus Torvalds 已提交
5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232
	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;
	}

5233
	err = ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246
	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;

5247
	return ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259 5260 5261 5262
}

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;

5263
	return ipc_has_perm(ipcp, av);
L
Linus Torvalds 已提交
5264 5265
}

5266 5267 5268 5269 5270 5271
static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
{
	struct ipc_security_struct *isec = ipcp->security;
	*secid = isec->sid;
}

5272
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
L
Linus Torvalds 已提交
5273 5274 5275 5276 5277 5278
{
	if (inode)
		inode_doinit_with_dentry(inode, dentry);
}

static int selinux_getprocattr(struct task_struct *p,
5279
			       char *name, char **value)
L
Linus Torvalds 已提交
5280
{
5281
	const struct task_security_struct *__tsec;
5282
	u32 sid;
L
Linus Torvalds 已提交
5283
	int error;
5284
	unsigned len;
L
Linus Torvalds 已提交
5285 5286

	if (current != p) {
5287
		error = current_has_perm(p, PROCESS__GETATTR);
L
Linus Torvalds 已提交
5288 5289 5290 5291
		if (error)
			return error;
	}

5292 5293
	rcu_read_lock();
	__tsec = __task_cred(p)->security;
L
Linus Torvalds 已提交
5294 5295

	if (!strcmp(name, "current"))
5296
		sid = __tsec->sid;
L
Linus Torvalds 已提交
5297
	else if (!strcmp(name, "prev"))
5298
		sid = __tsec->osid;
L
Linus Torvalds 已提交
5299
	else if (!strcmp(name, "exec"))
5300
		sid = __tsec->exec_sid;
L
Linus Torvalds 已提交
5301
	else if (!strcmp(name, "fscreate"))
5302
		sid = __tsec->create_sid;
5303
	else if (!strcmp(name, "keycreate"))
5304
		sid = __tsec->keycreate_sid;
5305
	else if (!strcmp(name, "sockcreate"))
5306
		sid = __tsec->sockcreate_sid;
L
Linus Torvalds 已提交
5307
	else
5308 5309
		goto invalid;
	rcu_read_unlock();
L
Linus Torvalds 已提交
5310 5311 5312 5313

	if (!sid)
		return 0;

5314 5315 5316 5317
	error = security_sid_to_context(sid, value, &len);
	if (error)
		return error;
	return len;
5318 5319 5320 5321

invalid:
	rcu_read_unlock();
	return -EINVAL;
L
Linus Torvalds 已提交
5322 5323 5324 5325 5326 5327
}

static int selinux_setprocattr(struct task_struct *p,
			       char *name, void *value, size_t size)
{
	struct task_security_struct *tsec;
R
Roland McGrath 已提交
5328
	struct task_struct *tracer;
D
David Howells 已提交
5329 5330
	struct cred *new;
	u32 sid = 0, ptsid;
L
Linus Torvalds 已提交
5331 5332 5333 5334 5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345
	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"))
5346
		error = current_has_perm(p, PROCESS__SETEXEC);
L
Linus Torvalds 已提交
5347
	else if (!strcmp(name, "fscreate"))
5348
		error = current_has_perm(p, PROCESS__SETFSCREATE);
5349
	else if (!strcmp(name, "keycreate"))
5350
		error = current_has_perm(p, PROCESS__SETKEYCREATE);
5351
	else if (!strcmp(name, "sockcreate"))
5352
		error = current_has_perm(p, PROCESS__SETSOCKCREATE);
L
Linus Torvalds 已提交
5353
	else if (!strcmp(name, "current"))
5354
		error = current_has_perm(p, PROCESS__SETCURRENT);
L
Linus Torvalds 已提交
5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366
	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--;
		}
		error = security_context_to_sid(value, size, &sid);
5367
		if (error == -EINVAL && !strcmp(name, "fscreate")) {
5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 5381 5382
			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);

5383
				return error;
5384
			}
5385 5386 5387
			error = security_context_to_sid_force(value, size,
							      &sid);
		}
L
Linus Torvalds 已提交
5388 5389 5390 5391
		if (error)
			return error;
	}

D
David Howells 已提交
5392 5393 5394 5395
	new = prepare_creds();
	if (!new)
		return -ENOMEM;

L
Linus Torvalds 已提交
5396 5397 5398
	/* 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
5399
	   operation.  See selinux_bprm_set_creds for the execve
L
Linus Torvalds 已提交
5400 5401
	   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
5402 5403
	tsec = new->security;
	if (!strcmp(name, "exec")) {
L
Linus Torvalds 已提交
5404
		tsec->exec_sid = sid;
D
David Howells 已提交
5405
	} else if (!strcmp(name, "fscreate")) {
L
Linus Torvalds 已提交
5406
		tsec->create_sid = sid;
D
David Howells 已提交
5407
	} else if (!strcmp(name, "keycreate")) {
5408 5409
		error = may_create_key(sid, p);
		if (error)
D
David Howells 已提交
5410
			goto abort_change;
5411
		tsec->keycreate_sid = sid;
D
David Howells 已提交
5412
	} else if (!strcmp(name, "sockcreate")) {
5413
		tsec->sockcreate_sid = sid;
D
David Howells 已提交
5414 5415
	} else if (!strcmp(name, "current")) {
		error = -EINVAL;
L
Linus Torvalds 已提交
5416
		if (sid == 0)
D
David Howells 已提交
5417 5418 5419 5420
			goto abort_change;

		/* Only allow single threaded processes to change context */
		error = -EPERM;
5421
		if (!current_is_single_threaded()) {
D
David Howells 已提交
5422 5423 5424
			error = security_bounded_transition(tsec->sid, sid);
			if (error)
				goto abort_change;
5425
		}
L
Linus Torvalds 已提交
5426 5427 5428

		/* Check permissions for the transition. */
		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5429
				     PROCESS__DYNTRANSITION, NULL);
L
Linus Torvalds 已提交
5430
		if (error)
D
David Howells 已提交
5431
			goto abort_change;
L
Linus Torvalds 已提交
5432 5433 5434

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and fail. */
D
David Howells 已提交
5435
		ptsid = 0;
L
Linus Torvalds 已提交
5436
		task_lock(p);
5437
		tracer = ptrace_parent(p);
D
David Howells 已提交
5438 5439 5440 5441 5442 5443 5444
		if (tracer)
			ptsid = task_sid(tracer);
		task_unlock(p);

		if (tracer) {
			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
					     PROCESS__PTRACE, NULL);
L
Linus Torvalds 已提交
5445
			if (error)
D
David Howells 已提交
5446
				goto abort_change;
L
Linus Torvalds 已提交
5447 5448
		}

D
David Howells 已提交
5449 5450 5451 5452 5453 5454 5455
		tsec->sid = sid;
	} else {
		error = -EINVAL;
		goto abort_change;
	}

	commit_creds(new);
L
Linus Torvalds 已提交
5456
	return size;
D
David Howells 已提交
5457 5458 5459 5460

abort_change:
	abort_creds(new);
	return error;
L
Linus Torvalds 已提交
5461 5462
}

5463 5464 5465 5466 5467
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
	return security_sid_to_context(secid, secdata, seclen);
}

5468
static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5469 5470 5471 5472
{
	return security_context_to_sid(secdata, seclen, secid);
}

5473 5474
static void selinux_release_secctx(char *secdata, u32 seclen)
{
5475
	kfree(secdata);
5476 5477
}

5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503
/*
 *	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;
}
5504 5505
#ifdef CONFIG_KEYS

D
David Howells 已提交
5506
static int selinux_key_alloc(struct key *k, const struct cred *cred,
5507
			     unsigned long flags)
5508
{
D
David Howells 已提交
5509
	const struct task_security_struct *tsec;
5510 5511 5512 5513 5514 5515
	struct key_security_struct *ksec;

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

D
David Howells 已提交
5516 5517 5518
	tsec = cred->security;
	if (tsec->keycreate_sid)
		ksec->sid = tsec->keycreate_sid;
5519
	else
D
David Howells 已提交
5520
		ksec->sid = tsec->sid;
5521

5522
	k->security = ksec;
5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534
	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
5535 5536
				  const struct cred *cred,
				  key_perm_t perm)
5537 5538 5539
{
	struct key *key;
	struct key_security_struct *ksec;
5540
	u32 sid;
5541 5542 5543 5544 5545 5546 5547

	/* 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
5548
	sid = cred_sid(cred);
5549 5550 5551 5552 5553

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

	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5554 5555
}

5556 5557 5558 5559 5560 5561 5562 5563 5564 5565 5566 5567 5568 5569
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;
}

5570 5571
#endif

L
Linus Torvalds 已提交
5572
static struct security_operations selinux_ops = {
5573 5574
	.name =				"selinux",

5575
	.ptrace_access_check =		selinux_ptrace_access_check,
5576
	.ptrace_traceme =		selinux_ptrace_traceme,
L
Linus Torvalds 已提交
5577
	.capget =			selinux_capget,
D
David Howells 已提交
5578
	.capset =			selinux_capset,
L
Linus Torvalds 已提交
5579 5580 5581 5582 5583 5584 5585 5586
	.capable =			selinux_capable,
	.quotactl =			selinux_quotactl,
	.quota_on =			selinux_quota_on,
	.syslog =			selinux_syslog,
	.vm_enough_memory =		selinux_vm_enough_memory,

	.netlink_send =			selinux_netlink_send,

5587 5588 5589
	.bprm_set_creds =		selinux_bprm_set_creds,
	.bprm_committing_creds =	selinux_bprm_committing_creds,
	.bprm_committed_creds =		selinux_bprm_committed_creds,
L
Linus Torvalds 已提交
5590 5591 5592 5593 5594
	.bprm_secureexec =		selinux_bprm_secureexec,

	.sb_alloc_security =		selinux_sb_alloc_security,
	.sb_free_security =		selinux_sb_free_security,
	.sb_copy_data =			selinux_sb_copy_data,
5595
	.sb_remount =			selinux_sb_remount,
5596
	.sb_kern_mount =		selinux_sb_kern_mount,
5597
	.sb_show_options =		selinux_sb_show_options,
L
Linus Torvalds 已提交
5598 5599 5600
	.sb_statfs =			selinux_sb_statfs,
	.sb_mount =			selinux_mount,
	.sb_umount =			selinux_umount,
5601
	.sb_set_mnt_opts =		selinux_set_mnt_opts,
5602
	.sb_clone_mnt_opts =		selinux_sb_clone_mnt_opts,
5603 5604
	.sb_parse_opts_str = 		selinux_parse_opts_str,

L
Linus Torvalds 已提交
5605 5606 5607

	.inode_alloc_security =		selinux_inode_alloc_security,
	.inode_free_security =		selinux_inode_free_security,
5608
	.inode_init_security =		selinux_inode_init_security,
L
Linus Torvalds 已提交
5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620 5621 5622 5623 5624 5625 5626
	.inode_create =			selinux_inode_create,
	.inode_link =			selinux_inode_link,
	.inode_unlink =			selinux_inode_unlink,
	.inode_symlink =		selinux_inode_symlink,
	.inode_mkdir =			selinux_inode_mkdir,
	.inode_rmdir =			selinux_inode_rmdir,
	.inode_mknod =			selinux_inode_mknod,
	.inode_rename =			selinux_inode_rename,
	.inode_readlink =		selinux_inode_readlink,
	.inode_follow_link =		selinux_inode_follow_link,
	.inode_permission =		selinux_inode_permission,
	.inode_setattr =		selinux_inode_setattr,
	.inode_getattr =		selinux_inode_getattr,
	.inode_setxattr =		selinux_inode_setxattr,
	.inode_post_setxattr =		selinux_inode_post_setxattr,
	.inode_getxattr =		selinux_inode_getxattr,
	.inode_listxattr =		selinux_inode_listxattr,
	.inode_removexattr =		selinux_inode_removexattr,
5627 5628 5629
	.inode_getsecurity =		selinux_inode_getsecurity,
	.inode_setsecurity =		selinux_inode_setsecurity,
	.inode_listsecurity =		selinux_inode_listsecurity,
5630
	.inode_getsecid =		selinux_inode_getsecid,
L
Linus Torvalds 已提交
5631 5632 5633 5634 5635

	.file_permission =		selinux_file_permission,
	.file_alloc_security =		selinux_file_alloc_security,
	.file_free_security =		selinux_file_free_security,
	.file_ioctl =			selinux_file_ioctl,
5636 5637
	.mmap_file =			selinux_mmap_file,
	.mmap_addr =			selinux_mmap_addr,
L
Linus Torvalds 已提交
5638 5639 5640 5641 5642 5643 5644
	.file_mprotect =		selinux_file_mprotect,
	.file_lock =			selinux_file_lock,
	.file_fcntl =			selinux_file_fcntl,
	.file_set_fowner =		selinux_file_set_fowner,
	.file_send_sigiotask =		selinux_file_send_sigiotask,
	.file_receive =			selinux_file_receive,

5645
	.file_open =			selinux_file_open,
5646

L
Linus Torvalds 已提交
5647
	.task_create =			selinux_task_create,
5648
	.cred_alloc_blank =		selinux_cred_alloc_blank,
5649
	.cred_free =			selinux_cred_free,
D
David Howells 已提交
5650
	.cred_prepare =			selinux_cred_prepare,
5651
	.cred_transfer =		selinux_cred_transfer,
5652 5653
	.kernel_act_as =		selinux_kernel_act_as,
	.kernel_create_files_as =	selinux_kernel_create_files_as,
5654
	.kernel_module_request =	selinux_kernel_module_request,
L
Linus Torvalds 已提交
5655 5656
	.task_setpgid =			selinux_task_setpgid,
	.task_getpgid =			selinux_task_getpgid,
5657
	.task_getsid =			selinux_task_getsid,
5658
	.task_getsecid =		selinux_task_getsecid,
L
Linus Torvalds 已提交
5659
	.task_setnice =			selinux_task_setnice,
5660
	.task_setioprio =		selinux_task_setioprio,
5661
	.task_getioprio =		selinux_task_getioprio,
L
Linus Torvalds 已提交
5662 5663 5664
	.task_setrlimit =		selinux_task_setrlimit,
	.task_setscheduler =		selinux_task_setscheduler,
	.task_getscheduler =		selinux_task_getscheduler,
5665
	.task_movememory =		selinux_task_movememory,
L
Linus Torvalds 已提交
5666 5667
	.task_kill =			selinux_task_kill,
	.task_wait =			selinux_task_wait,
5668
	.task_to_inode =		selinux_task_to_inode,
L
Linus Torvalds 已提交
5669 5670

	.ipc_permission =		selinux_ipc_permission,
5671
	.ipc_getsecid =			selinux_ipc_getsecid,
L
Linus Torvalds 已提交
5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 5683 5684 5685 5686 5687 5688

	.msg_msg_alloc_security =	selinux_msg_msg_alloc_security,
	.msg_msg_free_security =	selinux_msg_msg_free_security,

	.msg_queue_alloc_security =	selinux_msg_queue_alloc_security,
	.msg_queue_free_security =	selinux_msg_queue_free_security,
	.msg_queue_associate =		selinux_msg_queue_associate,
	.msg_queue_msgctl =		selinux_msg_queue_msgctl,
	.msg_queue_msgsnd =		selinux_msg_queue_msgsnd,
	.msg_queue_msgrcv =		selinux_msg_queue_msgrcv,

	.shm_alloc_security =		selinux_shm_alloc_security,
	.shm_free_security =		selinux_shm_free_security,
	.shm_associate =		selinux_shm_associate,
	.shm_shmctl =			selinux_shm_shmctl,
	.shm_shmat =			selinux_shm_shmat,

5689 5690
	.sem_alloc_security =		selinux_sem_alloc_security,
	.sem_free_security =		selinux_sem_free_security,
L
Linus Torvalds 已提交
5691 5692 5693 5694
	.sem_associate =		selinux_sem_associate,
	.sem_semctl =			selinux_sem_semctl,
	.sem_semop =			selinux_sem_semop,

5695
	.d_instantiate =		selinux_d_instantiate,
L
Linus Torvalds 已提交
5696

5697 5698
	.getprocattr =			selinux_getprocattr,
	.setprocattr =			selinux_setprocattr,
L
Linus Torvalds 已提交
5699

5700
	.secid_to_secctx =		selinux_secid_to_secctx,
5701
	.secctx_to_secid =		selinux_secctx_to_secid,
5702
	.release_secctx =		selinux_release_secctx,
5703 5704 5705
	.inode_notifysecctx =		selinux_inode_notifysecctx,
	.inode_setsecctx =		selinux_inode_setsecctx,
	.inode_getsecctx =		selinux_inode_getsecctx,
5706

5707
	.unix_stream_connect =		selinux_socket_unix_stream_connect,
L
Linus Torvalds 已提交
5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723
	.unix_may_send =		selinux_socket_unix_may_send,

	.socket_create =		selinux_socket_create,
	.socket_post_create =		selinux_socket_post_create,
	.socket_bind =			selinux_socket_bind,
	.socket_connect =		selinux_socket_connect,
	.socket_listen =		selinux_socket_listen,
	.socket_accept =		selinux_socket_accept,
	.socket_sendmsg =		selinux_socket_sendmsg,
	.socket_recvmsg =		selinux_socket_recvmsg,
	.socket_getsockname =		selinux_socket_getsockname,
	.socket_getpeername =		selinux_socket_getpeername,
	.socket_getsockopt =		selinux_socket_getsockopt,
	.socket_setsockopt =		selinux_socket_setsockopt,
	.socket_shutdown =		selinux_socket_shutdown,
	.socket_sock_rcv_skb =		selinux_socket_sock_rcv_skb,
C
Catherine Zhang 已提交
5724 5725
	.socket_getpeersec_stream =	selinux_socket_getpeersec_stream,
	.socket_getpeersec_dgram =	selinux_socket_getpeersec_dgram,
L
Linus Torvalds 已提交
5726 5727
	.sk_alloc_security =		selinux_sk_alloc_security,
	.sk_free_security =		selinux_sk_free_security,
5728
	.sk_clone_security =		selinux_sk_clone_security,
5729
	.sk_getsecid =			selinux_sk_getsecid,
5730 5731 5732
	.sock_graft =			selinux_sock_graft,
	.inet_conn_request =		selinux_inet_conn_request,
	.inet_csk_clone =		selinux_inet_csk_clone,
5733
	.inet_conn_established =	selinux_inet_conn_established,
5734 5735 5736
	.secmark_relabel_packet =	selinux_secmark_relabel_packet,
	.secmark_refcount_inc =		selinux_secmark_refcount_inc,
	.secmark_refcount_dec =		selinux_secmark_refcount_dec,
5737
	.req_classify_flow =		selinux_req_classify_flow,
5738 5739
	.tun_dev_alloc_security =	selinux_tun_dev_alloc_security,
	.tun_dev_free_security =	selinux_tun_dev_free_security,
5740
	.tun_dev_create =		selinux_tun_dev_create,
5741
	.tun_dev_attach_queue =		selinux_tun_dev_attach_queue,
5742
	.tun_dev_attach =		selinux_tun_dev_attach,
5743
	.tun_dev_open =			selinux_tun_dev_open,
5744
	.skb_owned_by =			selinux_skb_owned_by,
5745 5746 5747 5748 5749

#ifdef CONFIG_SECURITY_NETWORK_XFRM
	.xfrm_policy_alloc_security =	selinux_xfrm_policy_alloc,
	.xfrm_policy_clone_security =	selinux_xfrm_policy_clone,
	.xfrm_policy_free_security =	selinux_xfrm_policy_free,
C
Catherine Zhang 已提交
5750
	.xfrm_policy_delete_security =	selinux_xfrm_policy_delete,
5751 5752
	.xfrm_state_alloc =		selinux_xfrm_state_alloc,
	.xfrm_state_alloc_acquire =	selinux_xfrm_state_alloc_acquire,
5753
	.xfrm_state_free_security =	selinux_xfrm_state_free,
C
Catherine Zhang 已提交
5754
	.xfrm_state_delete_security =	selinux_xfrm_state_delete,
5755
	.xfrm_policy_lookup =		selinux_xfrm_policy_lookup,
5756 5757
	.xfrm_state_pol_flow_match =	selinux_xfrm_state_pol_flow_match,
	.xfrm_decode_session =		selinux_xfrm_decode_session,
L
Linus Torvalds 已提交
5758
#endif
5759 5760

#ifdef CONFIG_KEYS
5761 5762 5763
	.key_alloc =			selinux_key_alloc,
	.key_free =			selinux_key_free,
	.key_permission =		selinux_key_permission,
5764
	.key_getsecurity =		selinux_key_getsecurity,
5765
#endif
5766 5767 5768 5769 5770 5771 5772

#ifdef CONFIG_AUDIT
	.audit_rule_init =		selinux_audit_rule_init,
	.audit_rule_known =		selinux_audit_rule_known,
	.audit_rule_match =		selinux_audit_rule_match,
	.audit_rule_free =		selinux_audit_rule_free,
#endif
L
Linus Torvalds 已提交
5773 5774 5775 5776
};

static __init int selinux_init(void)
{
5777 5778 5779 5780 5781
	if (!security_module_enable(&selinux_ops)) {
		selinux_enabled = 0;
		return 0;
	}

L
Linus Torvalds 已提交
5782 5783 5784 5785 5786 5787 5788 5789
	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
5790
	cred_init_security();
L
Linus Torvalds 已提交
5791

5792 5793
	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);

5794 5795
	sel_inode_cache = kmem_cache_create("selinux_inode_security",
					    sizeof(struct inode_security_struct),
5796
					    0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
5797 5798
	avc_init();

5799
	if (register_security(&selinux_ops))
L
Linus Torvalds 已提交
5800 5801
		panic("SELinux: Unable to register with kernel.\n");

5802
	if (selinux_enforcing)
5803
		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
5804
	else
5805
		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
5806

L
Linus Torvalds 已提交
5807 5808 5809
	return 0;
}

5810 5811 5812 5813 5814
static void delayed_superblock_init(struct super_block *sb, void *unused)
{
	superblock_doinit(sb, NULL);
}

L
Linus Torvalds 已提交
5815 5816
void selinux_complete_init(void)
{
5817
	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
L
Linus Torvalds 已提交
5818 5819

	/* Set up any superblocks initialized prior to the policy load. */
5820
	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
5821
	iterate_supers(delayed_superblock_init, NULL);
L
Linus Torvalds 已提交
5822 5823 5824 5825 5826 5827
}

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

5828
#if defined(CONFIG_NETFILTER)
L
Linus Torvalds 已提交
5829

5830 5831 5832 5833
static struct nf_hook_ops selinux_ipv4_ops[] = {
	{
		.hook =		selinux_ipv4_postroute,
		.owner =	THIS_MODULE,
5834
		.pf =		NFPROTO_IPV4,
5835 5836 5837 5838 5839 5840
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv4_forward,
		.owner =	THIS_MODULE,
5841
		.pf =		NFPROTO_IPV4,
5842 5843
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
5844 5845 5846 5847
	},
	{
		.hook =		selinux_ipv4_output,
		.owner =	THIS_MODULE,
5848
		.pf =		NFPROTO_IPV4,
5849 5850
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
5851
	}
L
Linus Torvalds 已提交
5852 5853 5854 5855
};

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

5856 5857 5858 5859
static struct nf_hook_ops selinux_ipv6_ops[] = {
	{
		.hook =		selinux_ipv6_postroute,
		.owner =	THIS_MODULE,
5860
		.pf =		NFPROTO_IPV6,
5861 5862 5863 5864 5865 5866
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP6_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv6_forward,
		.owner =	THIS_MODULE,
5867
		.pf =		NFPROTO_IPV6,
5868 5869 5870
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
	}
L
Linus Torvalds 已提交
5871 5872 5873 5874 5875 5876 5877 5878 5879 5880
};

#endif	/* IPV6 */

static int __init selinux_nf_ip_init(void)
{
	int err = 0;

	if (!selinux_enabled)
		goto out;
5881 5882 5883

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

5884 5885 5886
	err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
	if (err)
		panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
L
Linus Torvalds 已提交
5887 5888

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5889 5890 5891
	err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
	if (err)
		panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
L
Linus Torvalds 已提交
5892
#endif	/* IPV6 */
5893

L
Linus Torvalds 已提交
5894 5895 5896 5897 5898 5899 5900 5901 5902
out:
	return err;
}

__initcall(selinux_nf_ip_init);

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static void selinux_nf_ip_exit(void)
{
5903
	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
L
Linus Torvalds 已提交
5904

5905
	nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
L
Linus Torvalds 已提交
5906
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5907
	nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
L
Linus Torvalds 已提交
5908 5909 5910 5911
#endif	/* IPV6 */
}
#endif

5912
#else /* CONFIG_NETFILTER */
L
Linus Torvalds 已提交
5913 5914 5915 5916 5917

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
#define selinux_nf_ip_exit()
#endif

5918
#endif /* CONFIG_NETFILTER */
L
Linus Torvalds 已提交
5919 5920

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
5921 5922
static int selinux_disabled;

L
Linus Torvalds 已提交
5923 5924 5925 5926 5927 5928 5929 5930 5931 5932 5933 5934 5935 5936 5937
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;
5938
	selinux_enabled = 0;
L
Linus Torvalds 已提交
5939

5940
	reset_security_ops();
L
Linus Torvalds 已提交
5941

5942 5943 5944
	/* Try to destroy the avc node cache */
	avc_disable();

L
Linus Torvalds 已提交
5945 5946 5947 5948 5949 5950 5951 5952 5953
	/* Unregister netfilter hooks. */
	selinux_nf_ip_exit();

	/* Unregister selinuxfs. */
	exit_sel_fs();

	return 0;
}
#endif