/security/selinux/hooks.c

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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>
 *	      Chris Vance, <cvance@nai.com>
 *	      Wayne Salamon, <wsalamon@nai.com>
 *	      James Morris <jmorris@redhat.com>
 *
 *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
 *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
 *					   Eric Paris <eparis@redhat.com>
 *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
 *			    <dgoeddel@trustedcs.com>
 *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
 *	Paul Moore <paul@paul-moore.com>
 *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
 *		       Yuichi Nakamura <ynakam@hitachisoft.jp>
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License version 2,
 *	as published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/kd.h>
#include <linux/kernel.h>
#include <linux/tracehook.h>
#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>
#include <linux/proc_fs.h>
#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
#include <linux/dcache.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#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>
#include <net/ip.h>		
#include <net/tcp.h>		
#include <net/net_namespace.h>
#include <net/netlabel.h>
#include <linux/uaccess.h>
#include <asm/ioctls.h>
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>	
#include <linux/netlink.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/dccp.h>
#include <linux/quota.h>
#include <linux/un.h>		
#include <net/af_unix.h>	
#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>
#include <linux/string.h>
#include <linux/selinux.h>
#include <linux/mutex.h>
#include <linux/posix-timers.h>
#include <linux/syslog.h>
#include <linux/user_namespace.h>
#include <linux/export.h>
#include <linux/msg.h>
#include <linux/shm.h>

#include "avc.h"
#include "objsec.h"
#include "netif.h"
#include "netnode.h"
#include "netport.h"
#include "xfrm.h"
#include "netlabel.h"
#include "audit.h"
#include "avc_ss.h"

#define NUM_SEL_MNT_OPTS 5

extern struct security_operations *security_ops;

static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);

#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
int selinux_enforcing;

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

static struct kmem_cache *sel_inode_cache;

static int selinux_secmark_enabled(void)
{
	return (atomic_read(&selinux_secmark_refcount) > 0);
}

static void cred_init_security(void)
{
	struct cred *cred = (struct cred *) current->real_cred;
	struct task_security_struct *tsec;

	tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
	if (!tsec)
		panic("SELinux:  Failed to initialize initial task.\n");

	tsec->osid = tsec->sid = SECINITSID_KERNEL;
	cred->security = tsec;
}

static inline u32 cred_sid(const struct cred *cred)
{
	const struct task_security_struct *tsec;

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

static inline u32 task_sid(const struct task_struct *task)
{
	u32 sid;

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

static inline u32 current_sid(void)
{
	const struct task_security_struct *tsec = current_security();

	return tsec->sid;
}


static int inode_alloc_security(struct inode *inode)
{
	struct inode_security_struct *isec;
	u32 sid = current_sid();

	isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
	if (!isec)
		return -ENOMEM;

	mutex_init(&isec->lock);
	INIT_LIST_HEAD(&isec->list);
	isec->inode = inode;
	isec->sid = SECINITSID_UNLABELED;
	isec->sclass = SECCLASS_FILE;
	isec->task_sid = sid;
	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;
	kmem_cache_free(sel_inode_cache, isec);
}

static int file_alloc_security(struct file *file)
{
	struct file_security_struct *fsec;
	u32 sid = current_sid();

	fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
	if (!fsec)
		return -ENOMEM;

	fsec->sid = sid;
	fsec->fown_sid = sid;
	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;

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

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

	return 0;
}

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


static const char *labeling_behaviors[6] = {
	"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 {
	Opt_error = -1,
	Opt_context = 1,
	Opt_fscontext = 2,
	Opt_defcontext = 3,
	Opt_rootcontext = 4,
	Opt_labelsupport = 5,
};

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

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

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

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

static int sb_finish_set_opts(struct super_block *sb)
{
	struct superblock_security_struct *sbsec = sb->s_security;
	struct dentry *root = sb->s_root;
	struct inode *root_inode = root->d_inode;
	int rc = 0;

	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
		if (!root_inode->i_op->getxattr) {
			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
			       "xattr support\n", sb->s_id, sb->s_type->name);
			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 "
				       "%s) has no security xattr handler\n",
				       sb->s_id, sb->s_type->name);
			else
				printk(KERN_WARNING "SELinux: (dev %s, type "
				       "%s) getxattr errno %d\n", sb->s_id,
				       sb->s_type->name, -rc);
			goto out;
		}
	}

	sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);

	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
		       sb->s_id, sb->s_type->name);
	else
		printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
		       sb->s_id, sb->s_type->name,
		       labeling_behaviors[sbsec->behavior-1]);

	if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
	    sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
	    sbsec->behavior == SECURITY_FS_USE_NONE ||
	    sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
		sbsec->flags &= ~SE_SBLABELSUPP;

	
	if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
		sbsec->flags |= SE_SBLABELSUPP;

	
	rc = inode_doinit_with_dentry(root_inode, root);

	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;
}

static int selinux_get_mnt_opts(const struct super_block *sb,
				struct security_mnt_opts *opts)
{
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	char *context = NULL;
	u32 len;
	char tmp;

	security_init_mnt_opts(opts);

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

	if (!ss_initialized)
		return -EINVAL;

	tmp = sbsec->flags & SE_MNTMASK;
	
	for (i = 0; i < 8; i++) {
		if (tmp & 0x01)
			opts->num_mnt_opts++;
		tmp >>= 1;
	}
	
	if (sbsec->flags & SE_SBLABELSUPP)
		opts->num_mnt_opts++;

	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts) {
		rc = -ENOMEM;
		goto out_free;
	}

	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
		rc = -ENOMEM;
		goto out_free;
	}

	i = 0;
	if (sbsec->flags & FSCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->sid, &context, &len);
		if (rc)
			goto out_free;
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
	}
	if (sbsec->flags & CONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
		if (rc)
			goto out_free;
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
	}
	if (sbsec->flags & DEFCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
		if (rc)
			goto out_free;
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
	}
	if (sbsec->flags & ROOTCONTEXT_MNT) {
		struct inode *root = sbsec->sb->s_root->d_inode;
		struct inode_security_struct *isec = root->i_security;

		rc = security_sid_to_context(isec->sid, &context, &len);
		if (rc)
			goto out_free;
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
	}
	if (sbsec->flags & SE_SBLABELSUPP) {
		opts->mnt_opts[i] = NULL;
		opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
	}

	BUG_ON(i != opts->num_mnt_opts);

	return 0;

out_free:
	security_free_mnt_opts(opts);
	return rc;
}

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

	
	if (sbsec->flags & SE_SBINITIALIZED)
		if (!(sbsec->flags & flag) ||
		    (old_sid != new_sid))
			return 1;

	if (!(sbsec->flags & SE_SBINITIALIZED))
		if (mnt_flags & flag)
			return 1;
	return 0;
}

static int selinux_set_mnt_opts(struct super_block *sb,
				struct security_mnt_opts *opts)
{
	const struct cred *cred = current_cred();
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	const char *name = sb->s_type->name;
	struct inode *inode = sbsec->sb->s_root->d_inode;
	struct inode_security_struct *root_isec = inode->i_security;
	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
	u32 defcontext_sid = 0;
	char **mount_options = opts->mnt_opts;
	int *flags = opts->mnt_opts_flags;
	int num_opts = opts->num_mnt_opts;

	mutex_lock(&sbsec->lock);

	if (!ss_initialized) {
		if (!num_opts) {
			goto out;
		}
		rc = -EINVAL;
		printk(KERN_WARNING "SELinux: Unable to set superblock options "
			"before the security server is initialized\n");
		goto out;
	}

	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
	    && (num_opts == 0))
		goto out;

	for (i = 0; i < num_opts; i++) {
		u32 sid;

		if (flags[i] == SE_SBLABELSUPP)
			continue;
		rc = security_context_to_sid(mount_options[i],
					     strlen(mount_options[i]), &sid);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, name, rc);
			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;
		}
	}

	if (sbsec->flags & SE_SBINITIALIZED) {
		
		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
			goto out_double_mount;
		rc = 0;
		goto out;
	}

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

	
	rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
	if (rc) {
		printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
		       __func__, sb->s_type->name, rc);
		goto out;
	}

	
	if (fscontext_sid) {
		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
		if (rc)
			goto out;

		sbsec->sid = fscontext_sid;
	}

	if (context_sid) {
		if (!fscontext_sid) {
			rc = may_context_mount_sb_relabel(context_sid, sbsec,
							  cred);
			if (rc)
				goto out;
			sbsec->sid = context_sid;
		} else {
			rc = may_context_mount_inode_relabel(context_sid, sbsec,
							     cred);
			if (rc)
				goto out;
		}
		if (!rootcontext_sid)
			rootcontext_sid = context_sid;

		sbsec->mntpoint_sid = context_sid;
		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
	}

	if (rootcontext_sid) {
		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
						     cred);
		if (rc)
			goto out;

		root_isec->sid = rootcontext_sid;
		root_isec->initialized = 1;
	}

	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;
		}

		if (defcontext_sid != sbsec->def_sid) {
			rc = may_context_mount_inode_relabel(defcontext_sid,
							     sbsec, cred);
			if (rc)
				goto out;
		}

		sbsec->def_sid = defcontext_sid;
	}

	rc = sb_finish_set_opts(sb);
out:
	mutex_unlock(&sbsec->lock);
	return rc;
out_double_mount:
	rc = -EINVAL;
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
	goto out;
}

static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
					struct super_block *newsb)
{
	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
	struct superblock_security_struct *newsbsec = newsb->s_security;

	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);

	if (!ss_initialized)
		return;

	
	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));

	
	if (newsbsec->flags & SE_SBINITIALIZED)
		return;

	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;
	}
	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;

		newisec->sid = oldisec->sid;
	}

	sb_finish_set_opts(newsb);
	mutex_unlock(&newsbsec->lock);
}

static int selinux_parse_opts_str(char *options,
				  struct security_mnt_opts *opts)
{
	char *p;
	char *context = NULL, *defcontext = NULL;
	char *fscontext = NULL, *rootcontext = NULL;
	int rc, num_mnt_opts = 0;

	opts->num_mnt_opts = 0;

	
	while ((p = strsep(&options, "|")) != NULL) {
		int token;
		substring_t args[MAX_OPT_ARGS];

		if (!*p)
			continue;

		token = match_token(p, tokens, args);

		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;
		case Opt_labelsupport:
			break;
		default:
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux:  unknown mount option\n");
			goto out_err;

		}
	}

	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;
	}

	if (fscontext) {
		opts->mnt_opts[num_mnt_opts] = fscontext;
		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
	}
	if (context) {
		opts->mnt_opts[num_mnt_opts] = context;
		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
	}
	if (rootcontext) {
		opts->mnt_opts[num_mnt_opts] = rootcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
	}
	if (defcontext) {
		opts->mnt_opts[num_mnt_opts] = defcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
	}

	opts->num_mnt_opts = num_mnt_opts;
	return 0;

out_err:
	kfree(context);
	kfree(defcontext);
	kfree(fscontext);
	kfree(rootcontext);
	return rc;
}
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;
}

static void selinux_write_opts(struct seq_file *m,
			       struct security_mnt_opts *opts)
{
	int i;
	char *prefix;

	for (i = 0; i < opts->num_mnt_opts; i++) {
		char *has_comma;

		if (opts->mnt_opts[i])
			has_comma = strchr(opts->mnt_opts[i], ',');
		else
			has_comma = NULL;

		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;
		case SE_SBLABELSUPP:
			seq_putc(m, ',');
			seq_puts(m, LABELSUPP_STR);
			continue;
		default:
			BUG();
			return;
		};
		
		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);
	if (rc) {
		
		if (rc == -EINVAL)
			rc = 0;
		return rc;
	}

	selinux_write_opts(m, &opts);

	security_free_mnt_opts(&opts);

	return rc;
}

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;
}

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);
}

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:
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
		case SOCK_DGRAM:
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
		default:
			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;
		case NETLINK_SOCK_DIAG:
			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;
		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
	}

	return SECCLASS_SOCKET;
}

#ifdef CONFIG_PROC_FS
static int selinux_proc_get_sid(struct dentry *dentry,
				u16 tclass,
				u32 *sid)
{
	int rc;
	char *buffer, *path;

	buffer = (char *)__get_free_page(GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
	if (IS_ERR(path))
		rc = PTR_ERR(path);
	else {
		while (path[1] >= '0' && path[1] <= '9') {
			path[1] = '/';
			path++;
		}
		rc = security_genfs_sid("proc", path, tclass, sid);
	}
	free_page((unsigned long)buffer);
	return rc;
}
#else
static int selinux_proc_get_sid(struct dentry *dentry,
				u16 tclass,
				u32 *sid)
{
	return -EINVAL;
}
#endif

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;

	mutex_lock(&isec->lock);
	if (isec->initialized)
		goto out_unlock;

	sbsec = inode->i_sb->s_security;
	if (!(sbsec->flags & SE_SBINITIALIZED)) {
		spin_lock(&sbsec->isec_lock);
		if (list_empty(&isec->list))
			list_add(&isec->list, &sbsec->isec_head);
		spin_unlock(&sbsec->isec_lock);
		goto out_unlock;
	}

	switch (sbsec->behavior) {
	case SECURITY_FS_USE_XATTR:
		if (!inode->i_op->getxattr) {
			isec->sid = sbsec->def_sid;
			break;
		}

		if (opt_dentry) {
			
			dentry = dget(opt_dentry);
		} else {
			
			dentry = d_find_alias(inode);
		}
		if (!dentry) {
			goto out_unlock;
		}

		len = INITCONTEXTLEN;
		context = kmalloc(len+1, GFP_NOFS);
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
			goto out_unlock;
		}
		context[len] = '\0';
		rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
					   context, len);
		if (rc == -ERANGE) {
			kfree(context);

			
			rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
						   NULL, 0);
			if (rc < 0) {
				dput(dentry);
				goto out_unlock;
			}
			len = rc;
			context = kmalloc(len+1, GFP_NOFS);
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
				goto out_unlock;
			}
			context[len] = '\0';
			rc = inode->i_op->getxattr(dentry,
						   XATTR_NAME_SELINUX,
						   context, len);
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
				       "%d for dev=%s ino=%ld\n", __func__,
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
				goto out_unlock;
			}
			
			sid = sbsec->def_sid;
			rc = 0;
		} else {
			rc = security_context_to_sid_default(context, rc, &sid,
							     sbsec->def_sid,
							     GFP_NOFS);
			if (rc) {
				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);
				}
				kfree(context);
				
				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:
		
		isec->sid = sbsec->sid;

		
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		rc = security_transition_sid(isec->task_sid, sbsec->sid,
					     isec->sclass, NULL, &sid);
		if (rc)
			goto out_unlock;
		isec->sid = sid;
		break;
	case SECURITY_FS_USE_MNTPOINT:
		isec->sid = sbsec->mntpoint_sid;
		break;
	default:
		
		isec->sid = sbsec->sid;

		if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
			if (opt_dentry) {
				isec->sclass = inode_mode_to_security_class(inode->i_mode);
				rc = selinux_proc_get_sid(opt_dentry,
							  isec->sclass,
							  &sid);
				if (rc)
					goto out_unlock;
				isec->sid = sid;
			}
		}
		break;
	}

	isec->initialized = 1;

out_unlock:
	mutex_unlock(&isec->lock);
out:
	if (isec->sclass == SECCLASS_FILE)
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
	return rc;
}

static inline u32 signal_to_av(int sig)
{
	u32 perm = 0;

	switch (sig) {
	case SIGCHLD:
		
		perm = PROCESS__SIGCHLD;
		break;
	case SIGKILL:
		
		perm = PROCESS__SIGKILL;
		break;
	case SIGSTOP:
		
		perm = PROCESS__SIGSTOP;
		break;
	default:
		
		perm = PROCESS__SIGNAL;
		break;
	}

	return perm;
}

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);
}

static int task_has_perm(const struct task_struct *tsk1,
			 const struct task_struct *tsk2,
			 u32 perms)
{
	const struct task_security_struct *__tsec1, *__tsec2;
	u32 sid1, sid2;

	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);
}

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);
}

#if CAP_LAST_CAP > 63
#error Fix SELinux to handle capabilities > 63.
#endif

static int cred_has_capability(const struct cred *cred,
			       int cap, int audit)
{
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};
	struct av_decision avd;
	u16 sclass;
	u32 sid = cred_sid(cred);
	u32 av = CAP_TO_MASK(cap);
	int rc;

	COMMON_AUDIT_DATA_INIT(&ad, CAP);
	ad.selinux_audit_data = &sad;
	ad.tsk = current;
	ad.u.cap = cap;

	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();
		return -EINVAL;
	}

	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
	if (audit == SECURITY_CAP_AUDIT) {
		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
		if (rc2)
			return rc2;
	}
	return rc;
}

static int task_has_system(struct task_struct *tsk,
			   u32 perms)
{
	u32 sid = task_sid(tsk);

	return avc_has_perm(sid, SECINITSID_KERNEL,
			    SECCLASS_SYSTEM, perms, NULL);
}

static int inode_has_perm(const struct cred *cred,
			  struct inode *inode,
			  u32 perms,
			  struct common_audit_data *adp,
			  unsigned flags)
{
	struct inode_security_struct *isec;
	u32 sid;

	validate_creds(cred);

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

	sid = cred_sid(cred);
	isec = inode->i_security;

	if (unlikely(isec == NULL)) {
		printk(KERN_WARNING "SELinux: inode->i_security is NULL, return 0 to aovid access isec this NULL pointer");
		return 0;
	}

	return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
}

static int inode_has_perm_noadp(const struct cred *cred,
				struct inode *inode,
				u32 perms,
				unsigned flags)
{
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};

	COMMON_AUDIT_DATA_INIT(&ad, INODE);
	ad.u.inode = inode;
	ad.selinux_audit_data = &sad;
	return inode_has_perm(cred, inode, perms, &ad, flags);
}

static inline int dentry_has_perm(const struct cred *cred,
				  struct dentry *dentry,
				  u32 av)
{
	struct inode *inode = dentry->d_inode;
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};

	COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
	ad.u.dentry = dentry;
	ad.selinux_audit_data = &sad;
	return inode_has_perm(cred, inode, av, &ad, 0);
}

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;
	struct selinux_audit_data sad = {0,};

	COMMON_AUDIT_DATA_INIT(&ad, PATH);
	ad.u.path = *path;
	ad.selinux_audit_data = &sad;
	return inode_has_perm(cred, inode, av, &ad, 0);
}

static int file_has_perm(const struct cred *cred,
			 struct file *file,
			 u32 av)
{
	struct file_security_struct *fsec = file->f_security;
	struct inode *inode = file->f_path.dentry->d_inode;
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};
	u32 sid = cred_sid(cred);
	int rc;

	COMMON_AUDIT_DATA_INIT(&ad, PATH);
	ad.u.path = file->f_path;
	ad.selinux_audit_data = &sad;

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

	
	rc = 0;
	if (av)
		rc = inode_has_perm(cred, inode, av, &ad, 0);

out:
	return rc;
}

static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
	const struct task_security_struct *tsec = current_security();
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
	u32 sid, newsid;
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};
	int rc;

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

	sid = tsec->sid;
	newsid = tsec->create_sid;

	COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
	ad.u.dentry = dentry;
	ad.selinux_audit_data = &sad;

	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
			  DIR__ADD_NAME | DIR__SEARCH,
			  &ad);
	if (rc)
		return rc;

	if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
		rc = security_transition_sid(sid, dsec->sid, tclass,
					     &dentry->d_name, &newsid);
		if (rc)
			return rc;
	}

	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
	if (rc)
		return rc;

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

static int may_create_key(u32 ksid,
			  struct task_struct *ctx)
{
	u32 sid = task_sid(ctx);

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

#define MAY_LINK	0
#define MAY_UNLINK	1
#define MAY_RMDIR	2

static int may_link(struct inode *dir,
		    struct dentry *dentry,
		    int kind)

{
	struct inode_security_struct *dsec, *isec;
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};
	u32 sid = current_sid();
	u32 av;
	int rc;

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

	COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
	ad.u.dentry = dentry;
	ad.selinux_audit_data = &sad;

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
	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:
		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
			__func__, kind);
		return 0;
	}

	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
	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;
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};
	u32 sid = current_sid();
	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;

	COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
	ad.selinux_audit_data = &sad;

	ad.u.dentry = old_dentry;
	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
	rc = avc_has_perm(sid, old_isec->sid,
			  old_isec->sclass, FILE__RENAME, &ad);
	if (rc)
		return rc;
	if (old_is_dir && new_dir != old_dir) {
		rc = avc_has_perm(sid, old_isec->sid,
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

	ad.u.dentry = new_dentry;
	av = DIR__ADD_NAME | DIR__SEARCH;
	if (new_dentry->d_inode)
		av |= DIR__REMOVE_NAME;
	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
	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);
		rc = avc_has_perm(sid, new_isec->sid,
				  new_isec->sclass,
				  (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
		if (rc)
			return rc;
	}

	return 0;
}

static int superblock_has_perm(const struct cred *cred,
			       struct super_block *sb,
			       u32 perms,
			       struct common_audit_data *ad)
{
	struct superblock_security_struct *sbsec;
	u32 sid = cred_sid(cred);

	sbsec = sb->s_security;
	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
}

static inline u32 file_mask_to_av(int mode, int mask)
{
	u32 av = 0;

	if (!S_ISDIR(mode)) {
		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;
}

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) {
		av = FILE__IOCTL;
	}

	return av;
}

static inline u32 open_file_to_av(struct file *file)
{
	u32 av = file_to_av(file);

	if (selinux_policycap_openperm)
		av |= FILE__OPEN;

	return av;
}


static int selinux_binder_set_context_mgr(struct task_struct *mgr)
{
	u32 mysid = current_sid();
	u32 mgrsid = task_sid(mgr);

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

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

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

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

static int selinux_binder_transfer_binder(struct task_struct *from, struct task_struct *to)
{
	u32 fromsid = task_sid(from);
	u32 tosid = task_sid(to);
	return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER, NULL);
}

static int selinux_binder_transfer_file(struct task_struct *from, struct task_struct *to, struct file *file)
{
	u32 sid = task_sid(to);
	struct file_security_struct *fsec = file->f_security;
	struct inode *inode = file->f_path.dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};
	int rc;

	COMMON_AUDIT_DATA_INIT(&ad, PATH);
	ad.u.path = file->f_path;
	ad.selinux_audit_data = &sad;

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

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

	return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
			    &ad);
}

static int selinux_ptrace_access_check(struct task_struct *child,
				     unsigned int mode)
{
	int rc;

	rc = cap_ptrace_access_check(child, mode);
	if (rc)
		return rc;

	if (mode & PTRACE_MODE_READ) {
		u32 sid = current_sid();
		u32 csid = task_sid(child);
		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
	}

	return current_has_perm(child, PROCESS__PTRACE);
}

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

	rc = cap_ptrace_traceme(parent);
	if (rc)
		return rc;

	return task_has_perm(parent, current, PROCESS__PTRACE);
}

static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
	int error;

	error = current_has_perm(target, PROCESS__GETCAP);
	if (error)
		return error;

	return cap_capget(target, effective, inheritable, permitted);
}

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)
{
	int error;

	error = cap_capset(new, old,
				      effective, inheritable, permitted);
	if (error)
		return error;

	return cred_has_perm(old, new, PROCESS__SETCAP);
}


static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
			   int cap, int audit)
{
	int rc;

	rc = cap_capable(cred, ns, cap, audit);
	if (rc)
		return rc;

	return cred_has_capability(cred, cap, audit);
}

static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
{
	const struct cred *cred = current_cred();
	int rc = 0;

	if (!sb)
		return 0;

	switch (cmds) {
	case Q_SYNC:
	case Q_QUOTAON:
	case Q_QUOTAOFF:
	case Q_SETINFO:
	case Q_SETQUOTA:
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
		break;
	case Q_GETFMT:
	case Q_GETINFO:
	case Q_GETQUOTA:
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
		break;
	default:
		rc = 0;  
		break;
	}
	return rc;
}

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

	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
}

static int selinux_syslog(int type)
{
	int rc;

	switch (type) {
	case SYSLOG_ACTION_READ_ALL:	
	case SYSLOG_ACTION_SIZE_BUFFER:	
		rc = task_has_system(current, SYSTEM__SYSLOG_READ);
		break;
	case SYSLOG_ACTION_CONSOLE_OFF:	
	case SYSLOG_ACTION_CONSOLE_ON:	
	
	case SYSLOG_ACTION_CONSOLE_LEVEL:
		rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
		break;
	case SYSLOG_ACTION_CLOSE:	
	case SYSLOG_ACTION_OPEN:	
	case SYSLOG_ACTION_READ:	
	case SYSLOG_ACTION_READ_CLEAR:	
	case SYSLOG_ACTION_CLEAR:	
	default:
		rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
		break;
	}
	return rc;
}

static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
{
	int rc, cap_sys_admin = 0;

	rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
			     SECURITY_CAP_NOAUDIT);
	if (rc == 0)
		cap_sys_admin = 1;

	return __vm_enough_memory(mm, pages, cap_sys_admin);
}


static int selinux_bprm_set_creds(struct linux_binprm *bprm)
{
	const struct task_security_struct *old_tsec;
	struct task_security_struct *new_tsec;
	struct inode_security_struct *isec;
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};
	struct inode *inode = bprm->file->f_path.dentry->d_inode;
	int rc;

	rc = cap_bprm_set_creds(bprm);
	if (rc)
		return rc;

	if (bprm->cred_prepared)
		return 0;

	old_tsec = current_security();
	new_tsec = bprm->cred->security;
	isec = inode->i_security;

	
	new_tsec->sid = old_tsec->sid;
	new_tsec->osid = old_tsec->sid;

	
	new_tsec->create_sid = 0;
	new_tsec->keycreate_sid = 0;
	new_tsec->sockcreate_sid = 0;

	if (old_tsec->exec_sid) {
		new_tsec->sid = old_tsec->exec_sid;
		
		new_tsec->exec_sid = 0;
	} else {
		
		rc = security_transition_sid(old_tsec->sid, isec->sid,
					     SECCLASS_PROCESS, NULL,
					     &new_tsec->sid);
		if (rc)
			return rc;
	}

	COMMON_AUDIT_DATA_INIT(&ad, PATH);
	ad.selinux_audit_data = &sad;
	ad.u.path = bprm->file->f_path;

	if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
		new_tsec->sid = old_tsec->sid;

	if (new_tsec->sid == old_tsec->sid) {
		rc = avc_has_perm(old_tsec->sid, isec->sid,
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

		rc = avc_has_perm(new_tsec->sid, isec->sid,
				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
		if (rc)
			return rc;

		
		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;
		}

		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();
			tracer = ptrace_parent(current);
			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;
			}
		}

		
		bprm->per_clear |= PER_CLEAR_ON_SETID;
	}

	return 0;
}

static int selinux_bprm_secureexec(struct linux_binprm *bprm)
{
	const struct task_security_struct *tsec = current_security();
	u32 sid, osid;
	int atsecure = 0;

	sid = tsec->sid;
	osid = tsec->osid;

	if (osid != sid) {
		atsecure = avc_has_perm(osid, sid,
					SECCLASS_PROCESS,
					PROCESS__NOATSECURE, NULL);
	}

	return (atsecure || cap_bprm_secureexec(bprm));
}

static inline void flush_unauthorized_files(const struct cred *cred,
					    struct files_struct *files)
{
	struct common_audit_data ad;
	struct selinux_audit_data sad = {0,};
	struct file *file, *devnull = NULL;
	struct tty_struct *tty;
	struct fdtable *fdt;
	long j = -1;
	int drop_tty = 0;

	tty = get_current_tty();
	if (tty) {
		spin_lock(&tty_files_lock);
		if (!list_empty(&tty->tty_files)) {
			struct tty_file_private *file_priv;
			struct inode *inode;

			file_priv = list_first_entry(&tty->tty_files,
						struct tty_file_private, list);
			file = file_priv->file;
			inode = file->f_path.dentry->d_inode;
			if (inode_has_perm_noadp(cred, inode,
					   FILE__READ | FILE__WRITE, 0)) {
				drop_tty = 1;
			}
		}
		spin_unlock(&tty_files_lock);
		tty_kref_put(tty);
	}
	
	if (drop_tty)
		no_tty();

	

	COMMON_AUDIT_DATA_INIT(&ad, INODE);
	ad.selinux_audit_data = &sad;

	spin_lock(&files->file_lock);
	for (;;) {
		unsigned long set, i;
		int fd;

		j++;
		i = j * BITS_PER_LONG;
		fdt = files_fdtable(files);
		if (i >= fdt->max_fds)
			break;
		set = fdt->open_fds[j];
		if (!set)
			continue;
		spin_unlock(&files->file_lock);
		for ( ; set ; i++, set >>= 1) {
			if (set & 1) {
				file = fget(i);
				if (!file)
					continue;
				if (file_has_perm(cred,
						  file,
						  file_to_av(file))) {
					sys_close(i);
					fd = get_unused_fd();
					if (fd != i) {
						if (fd >= 0)
							put_unused_fd(fd);
						fput(file);
						continue;
					}
					if (devnull) {
						get_file(devnull);
					} else {
						devnull = dentry_open(
							dget(selinux_null),
							mntget(selinuxfs_mount),
							O_RDWR, cred);
						if (IS_ERR(devnull)) {
							devnull = NULL;
							put_unused_fd(fd);
							fput(file);
							continue;
						}
					}
					fd_install(fd, devnull);
				}
				fput(file);
			}
		}
		spin_lock(&files->file_lock);

	}
	spin_unlock(&files->file_lock);
}

static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
{
	struct task_security_struct *new_tsec;
	struct rlimit *rlim, *initrlim;
	int rc, i;

	new_tsec = bprm->cred->security;
	if (new_tsec->sid == new_tsec->osid)
		return;

	
	flush_unauthorized_files(bprm->cred, current->files);

	
	current->pdeath_signal = 0;

	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
			  PROCESS__RLIMITINH, NULL);
	if (rc) {
		
		task_lock(current);
		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);
		}
		task_unlock(current);
		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
	}
}

static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
{
	const struct task_security_struct *tsec = current_security();
	struct itimerval itimer;
	u32 osid, sid;
	int rc, i;

	osid = tsec->osid;
	sid = tsec->sid;

	if (sid == osid)
		return;

	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
	if (rc) {
		memset(&itimer, 0, sizeof itimer);
		for (i = 0; i < 3; i++)
			do_setitimer(i, &itimer, NULL);
		spin_lock_irq(&current->sighand->siglock);
		if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
			__flush_signals(current);
			flush_signal_handlers(current, 1);
			sigemptyset(&current->blocked);
		}
		spin_unlock_irq(&current->sighand->siglock);
	}

	read_lock(&tasklist_lock);
	__wake_up_parent(current, current->real_parent);
	read_unlock(&tasklist_lock);
}


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)
{
	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) ||
		match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
		match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
}

static inline void take_option(char **to, char *from, int *first, int len)
{
	if (!*first) {
		**to = ',';
		*to += 1;
	} else
		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}

static inline void take_selinux_option(char **to, char *from, int *first,
				       int len)
{
	int current_size = 0;

	if (!*first) {
		**to = '|';
		*to += 1;
	} else
		*first = 0;

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

static int selinux_sb_copy_data(char *orig, char *copy)
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_cur…