hooks.c 121.2 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>
 *            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 Red Hat, Inc., James Morris <jmorris@redhat.com>
 *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
 *                          <dgoeddel@trustedcs.com>
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 *  Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
 *                     Paul Moore, <paul.moore@hp.com>
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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,
 *      as published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/ptrace.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/swap.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/ext2_fs.h>
#include <linux/proc_fs.h>
#include <linux/kd.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/tty.h>
#include <net/icmp.h>
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#include <net/ip.h>		/* for local_port_range[] */
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#include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>	/* for network interface checks */
#include <linux/netlink.h>
#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/sysctl.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 "avc.h"
#include "objsec.h"
#include "netif.h"
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#include "xfrm.h"
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#include "netlabel.h"
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#define XATTR_SELINUX_SUFFIX "selinux"
#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX

extern unsigned int policydb_loaded_version;
extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
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extern int selinux_compat_net;
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#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
int selinux_enforcing = 0;

static int __init enforcing_setup(char *str)
{
	selinux_enforcing = simple_strtol(str,NULL,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)
{
	selinux_enabled = simple_strtol(str, NULL, 0);
	return 1;
}
__setup("selinux=", selinux_enabled_setup);
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#else
int selinux_enabled = 1;
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#endif

/* Original (dummy) security module. */
static struct security_operations *original_ops = NULL;

/* Minimal support for a secondary security module,
   just to allow the use of the dummy or capability modules.
   The owlsm module can alternatively be used as a secondary
   module as long as CONFIG_OWLSM_FD is not enabled. */
static struct security_operations *secondary_ops = NULL;

/* Lists of inode and superblock security structures initialized
   before the policy was loaded. */
static LIST_HEAD(superblock_security_head);
static DEFINE_SPINLOCK(sb_security_lock);

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static struct kmem_cache *sel_inode_cache;
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/* Return security context for a given sid or just the context 
   length if the buffer is null or length is 0 */
static int selinux_getsecurity(u32 sid, void *buffer, size_t size)
{
	char *context;
	unsigned len;
	int rc;

	rc = security_sid_to_context(sid, &context, &len);
	if (rc)
		return rc;

	if (!buffer || !size)
		goto getsecurity_exit;

	if (size < len) {
		len = -ERANGE;
		goto getsecurity_exit;
	}
	memcpy(buffer, context, len);

getsecurity_exit:
	kfree(context);
	return len;
}

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

static int task_alloc_security(struct task_struct *task)
{
	struct task_security_struct *tsec;

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

	tsec->task = task;
	tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
	task->security = tsec;

	return 0;
}

static void task_free_security(struct task_struct *task)
{
	struct task_security_struct *tsec = task->security;
	task->security = NULL;
	kfree(tsec);
}

static int inode_alloc_security(struct inode *inode)
{
	struct task_security_struct *tsec = current->security;
	struct inode_security_struct *isec;

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	isec = kmem_cache_zalloc(sel_inode_cache, GFP_KERNEL);
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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 = tsec->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 task_security_struct *tsec = current->security;
	struct file_security_struct *fsec;

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

	fsec->file = file;
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	fsec->sid = tsec->sid;
	fsec->fown_sid = tsec->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->list);
	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;

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

	sb->s_security = NULL;
	kfree(sbsec);
}

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static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
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{
	struct sk_security_struct *ssec;

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

	ssec->sk = sk;
	ssec->peer_sid = SECINITSID_UNLABELED;
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	ssec->sid = SECINITSID_UNLABELED;
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	sk->sk_security = ssec;

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	selinux_netlbl_sk_security_init(ssec, family);

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	return 0;
}

static void sk_free_security(struct sock *sk)
{
	struct sk_security_struct *ssec = sk->sk_security;

	sk->sk_security = NULL;
	kfree(ssec);
}

/* The security server must be initialized before
   any labeling or access decisions can be provided. */
extern int ss_initialized;

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

static 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 {
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	Opt_error = -1,
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	Opt_context = 1,
	Opt_fscontext = 2,
	Opt_defcontext = 4,
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	Opt_rootcontext = 8,
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};

static match_table_t tokens = {
	{Opt_context, "context=%s"},
	{Opt_fscontext, "fscontext=%s"},
	{Opt_defcontext, "defcontext=%s"},
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	{Opt_rootcontext, "rootcontext=%s"},
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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,
			struct task_security_struct *tsec)
{
	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,
			struct task_security_struct *tsec)
{
	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 try_context_mount(struct super_block *sb, void *data)
{
	char *context = NULL, *defcontext = NULL;
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	char *fscontext = NULL, *rootcontext = NULL;
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	const char *name;
	u32 sid;
	int alloc = 0, rc = 0, seen = 0;
	struct task_security_struct *tsec = current->security;
	struct superblock_security_struct *sbsec = sb->s_security;

	if (!data)
		goto out;

	name = sb->s_type->name;

	if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {

		/* NFS we understand. */
		if (!strcmp(name, "nfs")) {
			struct nfs_mount_data *d = data;

			if (d->version <  NFS_MOUNT_VERSION)
				goto out;

			if (d->context[0]) {
				context = d->context;
				seen |= Opt_context;
			}
		} else
			goto out;

	} else {
		/* Standard string-based options. */
		char *p, *options = data;

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

			if (!*p)
				continue;

			token = match_token(p, tokens, args);

			switch (token) {
			case Opt_context:
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				if (seen & (Opt_context|Opt_defcontext)) {
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					rc = -EINVAL;
					printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
					goto out_free;
				}
				context = match_strdup(&args[0]);
				if (!context) {
					rc = -ENOMEM;
					goto out_free;
				}
				if (!alloc)
					alloc = 1;
				seen |= Opt_context;
				break;

			case Opt_fscontext:
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				if (seen & Opt_fscontext) {
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					rc = -EINVAL;
					printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
					goto out_free;
				}
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				fscontext = match_strdup(&args[0]);
				if (!fscontext) {
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					rc = -ENOMEM;
					goto out_free;
				}
				if (!alloc)
					alloc = 1;
				seen |= Opt_fscontext;
				break;

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			case Opt_rootcontext:
				if (seen & Opt_rootcontext) {
					rc = -EINVAL;
					printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
					goto out_free;
				}
				rootcontext = match_strdup(&args[0]);
				if (!rootcontext) {
					rc = -ENOMEM;
					goto out_free;
				}
				if (!alloc)
					alloc = 1;
				seen |= Opt_rootcontext;
				break;

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			case Opt_defcontext:
				if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
					rc = -EINVAL;
					printk(KERN_WARNING "SELinux:  "
					       "defcontext option is invalid "
					       "for this filesystem type\n");
					goto out_free;
				}
				if (seen & (Opt_context|Opt_defcontext)) {
					rc = -EINVAL;
					printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
					goto out_free;
				}
				defcontext = match_strdup(&args[0]);
				if (!defcontext) {
					rc = -ENOMEM;
					goto out_free;
				}
				if (!alloc)
					alloc = 1;
				seen |= Opt_defcontext;
				break;

			default:
				rc = -EINVAL;
				printk(KERN_WARNING "SELinux:  unknown mount "
				       "option\n");
				goto out_free;

			}
		}
	}

	if (!seen)
		goto out;

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	/* sets the context of the superblock for the fs being mounted. */
	if (fscontext) {
		rc = security_context_to_sid(fscontext, strlen(fscontext), &sid);
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		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
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			       fscontext, sb->s_id, name, rc);
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			goto out_free;
		}

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		rc = may_context_mount_sb_relabel(sid, sbsec, tsec);
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		if (rc)
			goto out_free;

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		sbsec->sid = sid;
	}

	/*
	 * 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.
	 */
	if (context) {
		rc = security_context_to_sid(context, strlen(context), &sid);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       context, sb->s_id, name, rc);
			goto out_free;
		}

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		if (!fscontext) {
			rc = may_context_mount_sb_relabel(sid, sbsec, tsec);
			if (rc)
				goto out_free;
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			sbsec->sid = sid;
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		} else {
			rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
			if (rc)
				goto out_free;
		}
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		sbsec->mntpoint_sid = sid;
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		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
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	}

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	if (rootcontext) {
		struct inode *inode = sb->s_root->d_inode;
		struct inode_security_struct *isec = inode->i_security;
		rc = security_context_to_sid(rootcontext, strlen(rootcontext), &sid);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       rootcontext, sb->s_id, name, rc);
			goto out_free;
		}

		rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
		if (rc)
			goto out_free;

		isec->sid = sid;
		isec->initialized = 1;
	}

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	if (defcontext) {
		rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       defcontext, sb->s_id, name, rc);
			goto out_free;
		}

		if (sid == sbsec->def_sid)
			goto out_free;

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		rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
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		if (rc)
			goto out_free;

		sbsec->def_sid = sid;
	}

out_free:
	if (alloc) {
		kfree(context);
		kfree(defcontext);
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		kfree(fscontext);
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		kfree(rootcontext);
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	}
out:
	return rc;
}

static int superblock_doinit(struct super_block *sb, void *data)
{
	struct superblock_security_struct *sbsec = sb->s_security;
	struct dentry *root = sb->s_root;
	struct inode *inode = root->d_inode;
	int rc = 0;

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	mutex_lock(&sbsec->lock);
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	if (sbsec->initialized)
		goto out;

	if (!ss_initialized) {
		/* Defer initialization until selinux_complete_init,
		   after the initial policy is loaded and the security
		   server is ready to handle calls. */
		spin_lock(&sb_security_lock);
		if (list_empty(&sbsec->list))
			list_add(&sbsec->list, &superblock_security_head);
		spin_unlock(&sb_security_lock);
		goto out;
	}

	/* Determine the labeling behavior to use for this filesystem type. */
	rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
	if (rc) {
		printk(KERN_WARNING "%s:  security_fs_use(%s) returned %d\n",
		       __FUNCTION__, sb->s_type->name, rc);
		goto out;
	}

	rc = try_context_mount(sb, data);
	if (rc)
		goto out;

	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 (!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 = 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;
		}
	}

	if (strcmp(sb->s_type->name, "proc") == 0)
		sbsec->proc = 1;

	sbsec->initialized = 1;

	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
657
		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
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		       sb->s_id, sb->s_type->name);
	}
	else {
661
		printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
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		       sb->s_id, sb->s_type->name,
		       labeling_behaviors[sbsec->behavior-1]);
	}

	/* Initialize the root inode. */
	rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);

	/* 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:
693
	mutex_unlock(&sbsec->lock);
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	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;
}

720 721 722 723 724 725 726 727 728 729
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);
}

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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:
746 747 748 749
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
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		case SOCK_DGRAM:
751 752 753 754
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
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		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
757
		default:
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			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;
767
		case NETLINK_INET_DIAG:
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			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;
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		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
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		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
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	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
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	}

	return SECCLASS_SOCKET;
}

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

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

	buflen = PAGE_SIZE;
	end = buffer+buflen;
	*--end = '\0';
	buflen--;
	path = end-1;
	*path = '/';
	while (de && de != de->parent) {
		buflen -= de->namelen + 1;
		if (buflen < 0)
			break;
		end -= de->namelen;
		memcpy(end, de->name, de->namelen);
		*--end = '/';
		path = end;
		de = de->parent;
	}
	rc = security_genfs_sid("proc", path, tclass, sid);
	free_page((unsigned long)buffer);
	return rc;
}
#else
static int selinux_proc_get_sid(struct proc_dir_entry *de,
				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;

853
	mutex_lock(&isec->lock);
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	if (isec->initialized)
855
		goto out_unlock;
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	sbsec = inode->i_sb->s_security;
	if (!sbsec->initialized) {
		/* 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);
866
		goto out_unlock;
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	}

	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) {
			printk(KERN_WARNING "%s:  no dentry for dev=%s "
			       "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
			       inode->i_ino);
889
			goto out_unlock;
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		}

		len = INITCONTEXTLEN;
		context = kmalloc(len, GFP_KERNEL);
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
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			goto out_unlock;
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		}
		rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
					   context, len);
		if (rc == -ERANGE) {
			/* 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);
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				goto out_unlock;
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			}
			kfree(context);
			len = rc;
			context = kmalloc(len, GFP_KERNEL);
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
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				goto out_unlock;
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			}
			rc = inode->i_op->getxattr(dentry,
						   XATTR_NAME_SELINUX,
						   context, len);
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
				printk(KERN_WARNING "%s:  getxattr returned "
				       "%d for dev=%s ino=%ld\n", __FUNCTION__,
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
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				goto out_unlock;
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			}
			/* Map ENODATA to the default file SID */
			sid = sbsec->def_sid;
			rc = 0;
		} else {
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			rc = security_context_to_sid_default(context, rc, &sid,
			                                     sbsec->def_sid);
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			if (rc) {
				printk(KERN_WARNING "%s:  context_to_sid(%s) "
				       "returned %d for dev=%s ino=%ld\n",
				       __FUNCTION__, context, -rc,
				       inode->i_sb->s_id, inode->i_ino);
				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);
		rc = security_transition_sid(isec->task_sid,
					     sbsec->sid,
					     isec->sclass,
					     &sid);
		if (rc)
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			goto out_unlock;
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		isec->sid = sid;
		break;
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	case SECURITY_FS_USE_MNTPOINT:
		isec->sid = sbsec->mntpoint_sid;
		break;
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	default:
971
		/* Default to the fs superblock SID. */
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		isec->sid = sbsec->sid;

		if (sbsec->proc) {
			struct proc_inode *proci = PROC_I(inode);
			if (proci->pde) {
				isec->sclass = inode_mode_to_security_class(inode->i_mode);
				rc = selinux_proc_get_sid(proci->pde,
							  isec->sclass,
							  &sid);
				if (rc)
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					goto out_unlock;
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				isec->sid = sid;
			}
		}
		break;
	}

	isec->initialized = 1;

991 992
out_unlock:
	mutex_unlock(&isec->lock);
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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;
}

/* Check permission betweeen a pair of tasks, e.g. signal checks,
   fork check, ptrace check, etc. */
static int task_has_perm(struct task_struct *tsk1,
			 struct task_struct *tsk2,
			 u32 perms)
{
	struct task_security_struct *tsec1, *tsec2;

	tsec1 = tsk1->security;
	tsec2 = tsk2->security;
	return avc_has_perm(tsec1->sid, tsec2->sid,
			    SECCLASS_PROCESS, perms, NULL);
}

/* Check whether a task is allowed to use a capability. */
static int task_has_capability(struct task_struct *tsk,
			       int cap)
{
	struct task_security_struct *tsec;
	struct avc_audit_data ad;

	tsec = tsk->security;

	AVC_AUDIT_DATA_INIT(&ad,CAP);
	ad.tsk = tsk;
	ad.u.cap = cap;

	return avc_has_perm(tsec->sid, tsec->sid,
			    SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
}

/* Check whether a task is allowed to use a system operation. */
static int task_has_system(struct task_struct *tsk,
			   u32 perms)
{
	struct task_security_struct *tsec;

	tsec = tsk->security;

	return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
			    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). */
static int inode_has_perm(struct task_struct *tsk,
			  struct inode *inode,
			  u32 perms,
			  struct avc_audit_data *adp)
{
	struct task_security_struct *tsec;
	struct inode_security_struct *isec;
	struct avc_audit_data ad;

1081 1082 1083
	if (unlikely (IS_PRIVATE (inode)))
		return 0;

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	tsec = tsk->security;
	isec = inode->i_security;

	if (!adp) {
		adp = &ad;
		AVC_AUDIT_DATA_INIT(&ad, FS);
		ad.u.fs.inode = inode;
	}

	return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
}

/* 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. */
static inline int dentry_has_perm(struct task_struct *tsk,
				  struct vfsmount *mnt,
				  struct dentry *dentry,
				  u32 av)
{
	struct inode *inode = dentry->d_inode;
	struct avc_audit_data ad;
	AVC_AUDIT_DATA_INIT(&ad,FS);
	ad.u.fs.mnt = mnt;
	ad.u.fs.dentry = dentry;
	return inode_has_perm(tsk, inode, av, &ad);
}

/* 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. */
1120
static int file_has_perm(struct task_struct *tsk,
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				struct file *file,
				u32 av)
{
	struct task_security_struct *tsec = tsk->security;
	struct file_security_struct *fsec = file->f_security;
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	struct vfsmount *mnt = file->f_path.mnt;
	struct dentry *dentry = file->f_path.dentry;
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	struct inode *inode = dentry->d_inode;
	struct avc_audit_data ad;
	int rc;

	AVC_AUDIT_DATA_INIT(&ad, FS);
	ad.u.fs.mnt = mnt;
	ad.u.fs.dentry = dentry;

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

	/* av is zero if only checking access to the descriptor. */
	if (av)
		return inode_has_perm(tsk, inode, av, &ad);

	return 0;
}

/* Check whether a task can create a file. */
static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
	struct task_security_struct *tsec;
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
	u32 newsid;
	struct avc_audit_data ad;
	int rc;

	tsec = current->security;
	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

	AVC_AUDIT_DATA_INIT(&ad, FS);
	ad.u.fs.dentry = dentry;

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

	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
		newsid = tsec->create_sid;
	} else {
		rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
					     &newsid);
		if (rc)
			return rc;
	}

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

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

1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205
/* Check whether a task can create a key. */
static int may_create_key(u32 ksid,
			  struct task_struct *ctx)
{
	struct task_security_struct *tsec;

	tsec = ctx->security;

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

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

/* 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 task_security_struct *tsec;
	struct inode_security_struct *dsec, *isec;
	struct avc_audit_data ad;
	u32 av;
	int rc;

	tsec = current->security;
	dsec = dir->i_security;
	isec = dentry->d_inode->i_security;

	AVC_AUDIT_DATA_INIT(&ad, FS);
	ad.u.fs.dentry = dentry;

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
	rc = avc_has_perm(tsec->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 "may_link:  unrecognized kind %d\n", kind);
		return 0;
	}

	rc = avc_has_perm(tsec->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 task_security_struct *tsec;
	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
	struct avc_audit_data ad;
	u32 av;
	int old_is_dir, new_is_dir;
	int rc;

	tsec = current->security;
	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;

	AVC_AUDIT_DATA_INIT(&ad, FS);

	ad.u.fs.dentry = old_dentry;
	rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
	rc = avc_has_perm(tsec->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(tsec->sid, old_isec->sid,
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

	ad.u.fs.dentry = new_dentry;
	av = DIR__ADD_NAME | DIR__SEARCH;
	if (new_dentry->d_inode)
		av |= DIR__REMOVE_NAME;
	rc = avc_has_perm(tsec->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(tsec->sid, new_isec->sid,
				  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. */
static int superblock_has_perm(struct task_struct *tsk,
			       struct super_block *sb,
			       u32 perms,
			       struct avc_audit_data *ad)
{
	struct task_security_struct *tsec;
	struct superblock_security_struct *sbsec;

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

/* 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;

	if ((mode & S_IFMT) != S_IFDIR) {
		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;
}

/* 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;
	}

	return av;
}

/* Hook functions begin here. */

static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
{
	struct task_security_struct *psec = parent->security;
	struct task_security_struct *csec = child->security;
	int rc;

	rc = secondary_ops->ptrace(parent,child);
	if (rc)
		return rc;

	rc = task_has_perm(parent, child, PROCESS__PTRACE);
	/* Save the SID of the tracing process for later use in apply_creds. */
1384
	if (!(child->ptrace & PT_PTRACED) && !rc)
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		csec->ptrace_sid = psec->sid;
	return rc;
}

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

	error = task_has_perm(current, target, PROCESS__GETCAP);
	if (error)
		return error;

	return secondary_ops->capget(target, effective, inheritable, permitted);
}

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

	error = secondary_ops->capset_check(target, effective, inheritable, permitted);
	if (error)
		return error;

	return task_has_perm(current, target, PROCESS__SETCAP);
}

static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
                               kernel_cap_t *inheritable, kernel_cap_t *permitted)
{
	secondary_ops->capset_set(target, effective, inheritable, permitted);
}

static int selinux_capable(struct task_struct *tsk, int cap)
{
	int rc;

	rc = secondary_ops->capable(tsk, cap);
	if (rc)
		return rc;

	return task_has_capability(tsk,cap);
}

1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457
static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
{
	int buflen, rc;
	char *buffer, *path, *end;

	rc = -ENOMEM;
	buffer = (char*)__get_free_page(GFP_KERNEL);
	if (!buffer)
		goto out;

	buflen = PAGE_SIZE;
	end = buffer+buflen;
	*--end = '\0';
	buflen--;
	path = end-1;
	*path = '/';
	while (table) {
		const char *name = table->procname;
		size_t namelen = strlen(name);
		buflen -= namelen + 1;
		if (buflen < 0)
			goto out_free;
		end -= namelen;
		memcpy(end, name, namelen);
		*--end = '/';
		path = end;
		table = table->parent;
	}
1458 1459 1460 1461 1462 1463
	buflen -= 4;
	if (buflen < 0)
		goto out_free;
	end -= 4;
	memcpy(end, "/sys", 4);
	path = end;
1464 1465 1466 1467 1468 1469 1470
	rc = security_genfs_sid("proc", path, tclass, sid);
out_free:
	free_page((unsigned long)buffer);
out:
	return rc;
}

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static int selinux_sysctl(ctl_table *table, int op)
{
	int error = 0;
	u32 av;
	struct task_security_struct *tsec;
	u32 tsid;
	int rc;

	rc = secondary_ops->sysctl(table, op);
	if (rc)
		return rc;

	tsec = current->security;

1485 1486
	rc = selinux_sysctl_get_sid(table, (op == 0001) ?
				    SECCLASS_DIR : SECCLASS_FILE, &tsid);
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	if (rc) {
		/* Default to the well-defined sysctl SID. */
		tsid = SECINITSID_SYSCTL;
	}

	/* The op values are "defined" in sysctl.c, thereby creating
	 * a bad coupling between this module and sysctl.c */
	if(op == 001) {
		error = avc_has_perm(tsec->sid, tsid,
				     SECCLASS_DIR, DIR__SEARCH, NULL);
	} else {
		av = 0;
		if (op & 004)
			av |= FILE__READ;
		if (op & 002)
			av |= FILE__WRITE;
		if (av)
			error = avc_has_perm(tsec->sid, tsid,
					     SECCLASS_FILE, av, NULL);
        }

	return error;
}

static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
{
	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(current,
						 sb,
						 FILESYSTEM__QUOTAMOD, NULL);
			break;
	        case Q_GETFMT:
	        case Q_GETINFO:
		case Q_GETQUOTA:
			rc = superblock_has_perm(current,
						 sb,
						 FILESYSTEM__QUOTAGET, NULL);
			break;
		default:
			rc = 0;  /* let the kernel handle invalid cmds */
			break;
	}
	return rc;
}

static int selinux_quota_on(struct dentry *dentry)
{
	return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
}

static int selinux_syslog(int type)
{
	int rc;

	rc = secondary_ops->syslog(type);
	if (rc)
		return rc;

	switch (type) {
		case 3:         /* Read last kernel messages */
		case 10:        /* Return size of the log buffer */
			rc = task_has_system(current, SYSTEM__SYSLOG_READ);
			break;
		case 6:         /* Disable logging to console */
		case 7:         /* Enable logging to console */
		case 8:		/* Set level of messages printed to console */
			rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
			break;
		case 0:         /* Close log */
		case 1:         /* Open log */
		case 2:         /* Read from log */
		case 4:         /* Read/clear last kernel messages */
		case 5:         /* Clear ring buffer */
		default:
			rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
			break;
	}
	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.
 *
 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
 * if the capability is granted, but __vm_enough_memory requires 1 if
 * the capability is granted.
 *
 * Do not audit the selinux permission check, as this is applied to all
 * processes that allocate mappings.
 */
1589
static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
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{
	int rc, cap_sys_admin = 0;
	struct task_security_struct *tsec = current->security;

	rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
	if (rc == 0)
		rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1597 1598 1599 1600
					  SECCLASS_CAPABILITY,
					  CAP_TO_MASK(CAP_SYS_ADMIN),
					  0,
					  NULL);
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	if (rc == 0)
		cap_sys_admin = 1;

1605
	return __vm_enough_memory(mm, pages, cap_sys_admin);
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}

/* binprm security operations */

static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
{
	struct bprm_security_struct *bsec;

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	bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
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	if (!bsec)
		return -ENOMEM;

	bsec->bprm = bprm;
	bsec->sid = SECINITSID_UNLABELED;
	bsec->set = 0;

	bprm->security = bsec;
	return 0;
}

static int selinux_bprm_set_security(struct linux_binprm *bprm)
{
	struct task_security_struct *tsec;
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	struct inode *inode = bprm->file->f_path.dentry->d_inode;
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	struct inode_security_struct *isec;
	struct bprm_security_struct *bsec;
	u32 newsid;
	struct avc_audit_data ad;
	int rc;

	rc = secondary_ops->bprm_set_security(bprm);
	if (rc)
		return rc;

	bsec = bprm->security;

	if (bsec->set)
		return 0;

	tsec = current->security;
	isec = inode->i_security;

	/* Default to the current task SID. */
	bsec->sid = tsec->sid;

1651
	/* Reset fs, key, and sock SIDs on execve. */
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	tsec->create_sid = 0;
1653
	tsec->keycreate_sid = 0;
1654
	tsec->sockcreate_sid = 0;
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	if (tsec->exec_sid) {
		newsid = tsec->exec_sid;
		/* Reset exec SID on execve. */
		tsec->exec_sid = 0;
	} else {
		/* Check for a default transition on this program. */
		rc = security_transition_sid(tsec->sid, isec->sid,
		                             SECCLASS_PROCESS, &newsid);
		if (rc)
			return rc;
	}

	AVC_AUDIT_DATA_INIT(&ad, FS);
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	ad.u.fs.mnt = bprm->file->f_path.mnt;
	ad.u.fs.dentry = bprm->file->f_path.dentry;
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	if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
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		newsid = tsec->sid;

        if (tsec->sid == newsid) {
		rc = avc_has_perm(tsec->sid, isec->sid,
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		/* Check permissions for the transition. */
		rc = avc_has_perm(tsec->sid, newsid,
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

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

		/* Clear any possibly unsafe personality bits on exec: */
		current->personality &= ~PER_CLEAR_ON_SETID;

		/* Set the security field to the new SID. */
		bsec->sid = newsid;
	}

	bsec->set = 1;
	return 0;
}

static int selinux_bprm_check_security (struct linux_binprm *bprm)
{
	return secondary_ops->bprm_check_security(bprm);
}


static int selinux_bprm_secureexec (struct linux_binprm *bprm)
{
	struct task_security_struct *tsec = current->security;
	int atsecure = 0;

	if (tsec->osid != tsec->sid) {
		/* Enable secure mode for SIDs transitions unless
		   the noatsecure permission is granted between
		   the two SIDs, i.e. ahp returns 0. */
		atsecure = avc_has_perm(tsec->osid, tsec->sid,
					 SECCLASS_PROCESS,
					 PROCESS__NOATSECURE, NULL);
	}

	return (atsecure || secondary_ops->bprm_secureexec(bprm));
}

static void selinux_bprm_free_security(struct linux_binprm *bprm)
{
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Jesper Juhl 已提交
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	kfree(bprm->security);
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	bprm->security = NULL;
}

extern struct vfsmount *selinuxfs_mount;
extern struct dentry *selinux_null;

/* Derived from fs/exec.c:flush_old_files. */
static inline void flush_unauthorized_files(struct files_struct * files)
{
	struct avc_audit_data ad;
	struct file *file, *devnull = NULL;
1740
	struct tty_struct *tty;
1741
	struct fdtable *fdt;
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Linus Torvalds 已提交
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	long j = -1;
1743
	int drop_tty = 0;
L
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1745
	mutex_lock(&tty_mutex);
1746
	tty = get_current_tty();
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	if (tty) {
		file_list_lock();
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Eric Dumazet 已提交
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		file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
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		if (file) {
			/* Revalidate access to controlling tty.
			   Use inode_has_perm on the tty inode directly rather
			   than using file_has_perm, as this particular open
			   file may belong to another process and we are only
			   interested in the inode-based check here. */
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			struct inode *inode = file->f_path.dentry->d_inode;
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			if (inode_has_perm(current, inode,
					   FILE__READ | FILE__WRITE, NULL)) {
1759
				drop_tty = 1;
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			}
		}
		file_list_unlock();
	}
1764
	mutex_unlock(&tty_mutex);
1765 1766 1767
	/* Reset controlling tty. */
	if (drop_tty)
		no_tty();
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	/* Revalidate access to inherited open files. */

	AVC_AUDIT_DATA_INIT(&ad,FS);

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

		j++;
		i = j * __NFDBITS;
1780
		fdt = files_fdtable(files);
1781
		if (i >= fdt->max_fds)
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Linus Torvalds 已提交
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			break;
1783
		set = fdt->open_fds->fds_bits[j];
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		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(current,
						  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) {
1804
						get_file(devnull);
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					} else {
						devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1807 1808
						if (IS_ERR(devnull)) {
							devnull = NULL;
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							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_apply_creds(struct linux_binprm *bprm, int unsafe)
{
	struct task_security_struct *tsec;
	struct bprm_security_struct *bsec;
	u32 sid;
	int rc;

	secondary_ops->bprm_apply_creds(bprm, unsafe);

	tsec = current->security;

	bsec = bprm->security;
	sid = bsec->sid;

	tsec->osid = tsec->sid;
	bsec->unsafe = 0;
	if (tsec->sid != sid) {
		/* Check for shared state.  If not ok, leave SID
		   unchanged and kill. */
		if (unsafe & LSM_UNSAFE_SHARE) {
			rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
					PROCESS__SHARE, NULL);
			if (rc) {
				bsec->unsafe = 1;
				return;
			}
		}

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and kill. */
		if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
			rc = avc_has_perm(tsec->ptrace_sid, sid,
					  SECCLASS_PROCESS, PROCESS__PTRACE,
					  NULL);
			if (rc) {
				bsec->unsafe = 1;
				return;
			}
		}
		tsec->sid = sid;
	}
}

/*
 * called after apply_creds without the task lock held
 */
static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
{
	struct task_security_struct *tsec;
	struct rlimit *rlim, *initrlim;
	struct itimerval itimer;
	struct bprm_security_struct *bsec;
	int rc, i;

	tsec = current->security;
	bsec = bprm->security;

	if (bsec->unsafe) {
		force_sig_specific(SIGKILL, current);
		return;
	}
	if (tsec->osid == tsec->sid)
		return;

	/* Close files for which the new task SID is not authorized. */
	flush_unauthorized_files(current->files);

	/* 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(tsec->osid, tsec->sid, SECCLASS_PROCESS,
			  PROCESS__SIGINH, NULL);
	if (rc) {
		memset(&itimer, 0, sizeof itimer);
		for (i = 0; i < 3; i++)
			do_setitimer(i, &itimer, NULL);
		flush_signals(current);
		spin_lock_irq(&current->sighand->siglock);
		flush_signal_handlers(current, 1);
		sigemptyset(&current->blocked);
		recalc_sigpending();
		spin_unlock_irq(&current->sighand->siglock);
	}

1912 1913 1914
	/* Always clear parent death signal on SID transitions. */
	current->pdeath_signal = 0;

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	/* 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(tsec->osid, tsec->sid, SECCLASS_PROCESS,
			  PROCESS__RLIMITINH, NULL);
	if (rc) {
		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);
		}
		if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
			/*
			 * This will cause RLIMIT_CPU calculations
			 * to be refigured.
			 */
			current->it_prof_expires = jiffies_to_cputime(1);
		}
	}

	/* Wake up the parent if it is waiting so that it can
	   recheck wait permission to the new task SID. */
	wake_up_interruptible(&current->parent->signal->wait_chldexit);
}

/* 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)
{
	return (match_prefix("context=", sizeof("context=")-1, option, len) ||
	        match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1971 1972
	        match_prefix("defcontext=", sizeof("defcontext=")-1, option, len) ||
		match_prefix("rootcontext=", sizeof("rootcontext=")-1, option, len));
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}

static inline void take_option(char **to, char *from, int *first, int len)
{
	if (!*first) {
		**to = ',';
		*to += 1;
1980
	} else
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		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}

1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
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;
	}
}

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static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_curr, *in_end;
	char *sec_curr, *nosec_save, *nosec;
2013
	int open_quote = 0;
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	in_curr = orig;
	sec_curr = copy;

	/* Binary mount data: just copy */
	if (type->fs_flags & FS_BINARY_MOUNTDATA) {
		copy_page(sec_curr, in_curr);
		goto out;
	}

	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 {
2035 2036 2037 2038
		if (*in_end == '"')
			open_quote = !open_quote;
		if ((*in_end == ',' && open_quote == 0) ||
				*in_end == '\0') {
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			int len = in_end - in_curr;

			if (selinux_option(in_curr, len))
2042
				take_selinux_option(&sec_curr, in_curr, &fsec, len);
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			else
				take_option(&nosec, in_curr, &fnosec, len);

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

2050
	strcpy(in_save, nosec_save);
2051
	free_page((unsigned long)nosec_save);
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out:
	return rc;
}

static int selinux_sb_kern_mount(struct super_block *sb, void *data)
{
	struct avc_audit_data ad;
	int rc;

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

	AVC_AUDIT_DATA_INIT(&ad,FS);
	ad.u.fs.dentry = sb->s_root;
	return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
}

2070
static int selinux_sb_statfs(struct dentry *dentry)
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{
	struct avc_audit_data ad;

	AVC_AUDIT_DATA_INIT(&ad,FS);
2075 2076
	ad.u.fs.dentry = dentry->d_sb->s_root;
	return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
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}

static int selinux_mount(char * dev_name,
                         struct nameidata *nd,
                         char * type,
                         unsigned long flags,
                         void * data)
{
	int rc;

	rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
	if (rc)
		return rc;

	if (flags & MS_REMOUNT)
		return superblock_has_perm(current, nd->mnt->mnt_sb,
		                           FILESYSTEM__REMOUNT, NULL);
	else
		return dentry_has_perm(current, nd->mnt, nd->dentry,
		                       FILE__MOUNTON);
}

static int selinux_umount(struct vfsmount *mnt, int flags)
{
	int rc;

	rc = secondary_ops->sb_umount(mnt, flags);
	if (rc)
		return rc;

	return superblock_has_perm(current,mnt->mnt_sb,
	                           FILESYSTEM__UNMOUNT,NULL);
}

/* 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);
}

2123 2124 2125 2126 2127 2128 2129
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
				       char **name, void **value,
				       size_t *len)
{
	struct task_security_struct *tsec;
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
2130
	u32 newsid, clen;
2131
	int rc;
2132
	char *namep = NULL, *context;
2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153

	tsec = current->security;
	dsec = dir->i_security;
	sbsec = dir->i_sb->s_security;

	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
		newsid = tsec->create_sid;
	} else {
		rc = security_transition_sid(tsec->sid, dsec->sid,
					     inode_mode_to_security_class(inode->i_mode),
					     &newsid);
		if (rc) {
			printk(KERN_WARNING "%s:  "
			       "security_transition_sid failed, rc=%d (dev=%s "
			       "ino=%ld)\n",
			       __FUNCTION__,
			       -rc, inode->i_sb->s_id, inode->i_ino);
			return rc;
		}
	}

2154 2155 2156 2157 2158 2159 2160
	/* Possibly defer initialization to selinux_complete_init. */
	if (sbsec->initialized) {
		struct inode_security_struct *isec = inode->i_security;
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		isec->sid = newsid;
		isec->initialized = 1;
	}
2161

2162
	if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2163 2164
		return -EOPNOTSUPP;

2165 2166 2167 2168 2169 2170
	if (name) {
		namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
		if (!namep)
			return -ENOMEM;
		*name = namep;
	}
2171

2172 2173 2174 2175 2176 2177 2178 2179
	if (value && len) {
		rc = security_sid_to_context(newsid, &context, &clen);
		if (rc) {
			kfree(namep);
			return rc;
		}
		*value = context;
		*len = clen;
2180 2181 2182 2183 2184
	}

	return 0;
}

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static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
{
	return may_create(dir, dentry, SECCLASS_FILE);
}

static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
{
	int rc;

	rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
	if (rc)
		return rc;
	return may_link(dir, old_dentry, MAY_LINK);
}

static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
{
	int rc;

	rc = secondary_ops->inode_unlink(dir, dentry);
	if (rc)
		return rc;
	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);
}

static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
{
	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);
}

static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
	int rc;

	rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
	if (rc)
		return rc;

	return may_create(dir, dentry, inode_mode_to_security_class(mode));
}

static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
                                struct inode *new_inode, struct dentry *new_dentry)
{
	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
}

static int selinux_inode_readlink(struct dentry *dentry)
{
	return dentry_has_perm(current, NULL, dentry, FILE__READ);
}

static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
{
	int rc;

	rc = secondary_ops->inode_follow_link(dentry,nameidata);
	if (rc)
		return rc;
	return dentry_has_perm(current, NULL, dentry, FILE__READ);
}

static int selinux_inode_permission(struct inode *inode, int mask,
				    struct nameidata *nd)
{
	int rc;

	rc = secondary_ops->inode_permission(inode, mask, nd);
	if (rc)
		return rc;

	if (!mask) {
		/* No permission to check.  Existence test. */
		return 0;
	}

	return inode_has_perm(current, inode,
			       file_mask_to_av(inode->i_mode, mask), NULL);
}

static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
	int rc;

	rc = secondary_ops->inode_setattr(dentry, iattr);
	if (rc)
		return rc;

	if (iattr->ia_valid & ATTR_FORCE)
		return 0;

	if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
			       ATTR_ATIME_SET | ATTR_MTIME_SET))
		return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);

	return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
}

static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
	return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
}

static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
{
	struct task_security_struct *tsec = current->security;
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec;
	struct avc_audit_data ad;
	u32 newsid;
	int rc = 0;

	if (strcmp(name, XATTR_NAME_SELINUX)) {
		if (!strncmp(name, XATTR_SECURITY_PREFIX,
			     sizeof XATTR_SECURITY_PREFIX - 1) &&
		    !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. */
		return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
	}

	sbsec = inode->i_sb->s_security;
	if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
		return -EOPNOTSUPP;

2326
	if (!is_owner_or_cap(inode))
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		return -EPERM;

	AVC_AUDIT_DATA_INIT(&ad,FS);
	ad.u.fs.dentry = dentry;

	rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
			  FILE__RELABELFROM, &ad);
	if (rc)
		return rc;

	rc = security_context_to_sid(value, size, &newsid);
	if (rc)
		return rc;

	rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
			  FILE__RELABELTO, &ad);
	if (rc)
		return rc;

	rc = security_validate_transition(isec->sid, newsid, tsec->sid,
	                                  isec->sclass);
	if (rc)
		return rc;

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

static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
                                        void *value, size_t size, int flags)
{
	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;
	}

	rc = security_context_to_sid(value, size, &newsid);
	if (rc) {
		printk(KERN_WARNING "%s:  unable to obtain SID for context "
		       "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
		return;
	}

	isec->sid = newsid;
	return;
}

static int selinux_inode_getxattr (struct dentry *dentry, char *name)
{
	return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
}

static int selinux_inode_listxattr (struct dentry *dentry)
{
	return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
}

static int selinux_inode_removexattr (struct dentry *dentry, char *name)
{
	if (strcmp(name, XATTR_NAME_SELINUX)) {
		if (!strncmp(name, XATTR_SECURITY_PREFIX,
			     sizeof XATTR_SECURITY_PREFIX - 1) &&
		    !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. Might want a separate
		   permission for removexattr. */
		return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
	}

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

2414 2415 2416 2417 2418
static const char *selinux_inode_xattr_getsuffix(void)
{
      return XATTR_SELINUX_SUFFIX;
}

2419 2420 2421 2422 2423 2424 2425
/*
 * Copy the in-core inode security context value to the user.  If the
 * getxattr() prior to this succeeded, check to see if we need to
 * canonicalize the value to be finally returned to the user.
 *
 * Permission check is handled by selinux_inode_getxattr hook.
 */
2426
static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
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{
	struct inode_security_struct *isec = inode->i_security;
2429

2430 2431
	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;
2432

2433
	return selinux_getsecurity(isec->sid, buffer, size);
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}

static int selinux_inode_setsecurity(struct inode *inode, const char *name,
                                     const void *value, size_t size, int flags)
{
	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;

	rc = security_context_to_sid((void*)value, size, &newsid);
	if (rc)
		return rc;

	isec->sid = newsid;
	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;
}

/* file security operations */

static int selinux_file_permission(struct file *file, int mask)
{
V
Venkat Yekkirala 已提交
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	int rc;
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	struct inode *inode = file->f_path.dentry->d_inode;
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	if (!mask) {
		/* No permission to check.  Existence test. */
		return 0;
	}

	/* 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;

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	rc = file_has_perm(current, file,
			   file_mask_to_av(inode->i_mode, mask));
	if (rc)
		return rc;

	return selinux_netlbl_inode_permission(inode, mask);
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}

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)
{
	int error = 0;

	switch (cmd) {
		case FIONREAD:
		/* fall through */
		case FIBMAP:
		/* fall through */
		case FIGETBSZ:
		/* fall through */
		case EXT2_IOC_GETFLAGS:
		/* fall through */
		case EXT2_IOC_GETVERSION:
			error = file_has_perm(current, file, FILE__GETATTR);
			break;

		case EXT2_IOC_SETFLAGS:
		/* fall through */
		case EXT2_IOC_SETVERSION:
			error = file_has_perm(current, file, FILE__SETATTR);
			break;

		/* sys_ioctl() checks */
		case FIONBIO:
		/* fall through */
		case FIOASYNC:
			error = file_has_perm(current, file, 0);
			break;

	        case KDSKBENT:
	        case KDSKBSENT:
			error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
			break;

		/* default case assumes that the command will go
		 * to the file's ioctl() function.
		 */
		default:
			error = file_has_perm(current, file, FILE__IOCTL);

	}
	return error;
}

static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
#ifndef CONFIG_PPC32
	if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
		/*
		 * We are making executable an anonymous mapping or a
		 * private file mapping that will also be writable.
		 * This has an additional check.
		 */
		int rc = task_has_perm(current, current, PROCESS__EXECMEM);
		if (rc)
			return rc;
	}
#endif

	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;

		return file_has_perm(current, file, av);
	}
	return 0;
}

static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2577 2578
			     unsigned long prot, unsigned long flags,
			     unsigned long addr, unsigned long addr_only)
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{
2580 2581
	int rc = 0;
	u32 sid = ((struct task_security_struct*)(current->security))->sid;
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2583 2584 2585 2586
	if (addr < mmap_min_addr)
		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
				  MEMPROTECT__MMAP_ZERO, NULL);
	if (rc || addr_only)
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		return rc;

	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)
{
	int rc;

	rc = secondary_ops->file_mprotect(vma, reqprot, prot);
	if (rc)
		return rc;

	if (selinux_checkreqprot)
		prot = reqprot;

#ifndef CONFIG_PPC32
2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630
	if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
		rc = 0;
		if (vma->vm_start >= vma->vm_mm->start_brk &&
		    vma->vm_end <= vma->vm_mm->brk) {
			rc = task_has_perm(current, current,
					   PROCESS__EXECHEAP);
		} else if (!vma->vm_file &&
			   vma->vm_start <= vma->vm_mm->start_stack &&
			   vma->vm_end >= vma->vm_mm->start_stack) {
			rc = task_has_perm(current, current, PROCESS__EXECSTACK);
		} 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.
			 */
			rc = file_has_perm(current, vma->vm_file,
					   FILE__EXECMOD);
		}
2631 2632 2633
		if (rc)
			return rc;
	}
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#endif

	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)
{
	return file_has_perm(current, file, FILE__LOCK);
}

static int selinux_file_fcntl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
	int err = 0;

	switch (cmd) {
	        case F_SETFL:
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			if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
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				err = -EINVAL;
				break;
			}

			if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
				err = file_has_perm(current, file,FILE__WRITE);
				break;
			}
			/* fall through */
	        case F_SETOWN:
	        case F_SETSIG:
	        case F_GETFL:
	        case F_GETOWN:
	        case F_GETSIG:
			/* Just check FD__USE permission */
			err = file_has_perm(current, file, 0);
			break;
		case F_GETLK:
		case F_SETLK:
	        case F_SETLKW:
#if BITS_PER_LONG == 32
	        case F_GETLK64:
		case F_SETLK64:
	        case F_SETLKW64:
#endif
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			if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
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				err = -EINVAL;
				break;
			}
			err = file_has_perm(current, file, FILE__LOCK);
			break;
	}

	return err;
}

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

	tsec = current->security;
	fsec = file->f_security;
	fsec->fown_sid = tsec->sid;

	return 0;
}

static int selinux_file_send_sigiotask(struct task_struct *tsk,
				       struct fown_struct *fown, int signum)
{
        struct file *file;
	u32 perm;
	struct task_security_struct *tsec;
	struct file_security_struct *fsec;

	/* struct fown_struct is never outside the context of a struct file */
2709
        file = container_of(fown, struct file, f_owner);
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	tsec = tsk->security;
	fsec = file->f_security;

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

	return avc_has_perm(fsec->fown_sid, tsec->sid,
			    SECCLASS_PROCESS, perm, NULL);
}

static int selinux_file_receive(struct file *file)
{
	return file_has_perm(current, file, file_to_av(file));
}

/* task security operations */

static int selinux_task_create(unsigned long clone_flags)
{
	int rc;

	rc = secondary_ops->task_create(clone_flags);
	if (rc)
		return rc;

	return task_has_perm(current, current, PROCESS__FORK);
}

static int selinux_task_alloc_security(struct task_struct *tsk)
{
	struct task_security_struct *tsec1, *tsec2;
	int rc;

	tsec1 = current->security;

	rc = task_alloc_security(tsk);
	if (rc)
		return rc;
	tsec2 = tsk->security;

	tsec2->osid = tsec1->osid;
	tsec2->sid = tsec1->sid;

2756
	/* Retain the exec, fs, key, and sock SIDs across fork */
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	tsec2->exec_sid = tsec1->exec_sid;
	tsec2->create_sid = tsec1->create_sid;
2759
	tsec2->keycreate_sid = tsec1->keycreate_sid;
2760
	tsec2->sockcreate_sid = tsec1->sockcreate_sid;
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	/* Retain ptracer SID across fork, if any.
	   This will be reset by the ptrace hook upon any
	   subsequent ptrace_attach operations. */
	tsec2->ptrace_sid = tsec1->ptrace_sid;

	return 0;
}

static void selinux_task_free_security(struct task_struct *tsk)
{
	task_free_security(tsk);
}

static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
{
	/* 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. */
	return 0;
}

static int selinux_task_post_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
{
	return secondary_ops->task_post_setuid(id0,id1,id2,flags);
}

static int selinux_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags)
{
	/* See the comment for setuid above. */
	return 0;
}

static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
{
	return task_has_perm(current, p, PROCESS__SETPGID);
}

static int selinux_task_getpgid(struct task_struct *p)
{
	return task_has_perm(current, p, PROCESS__GETPGID);
}

static int selinux_task_getsid(struct task_struct *p)
{
	return task_has_perm(current, p, PROCESS__GETSESSION);
}

2812 2813 2814 2815 2816
static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
{
	selinux_get_task_sid(p, secid);
}

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2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833
static int selinux_task_setgroups(struct group_info *group_info)
{
	/* See the comment for setuid above. */
	return 0;
}

static int selinux_task_setnice(struct task_struct *p, int nice)
{
	int rc;

	rc = secondary_ops->task_setnice(p, nice);
	if (rc)
		return rc;

	return task_has_perm(current,p, PROCESS__SETSCHED);
}

2834 2835 2836 2837 2838
static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
	return task_has_perm(current, p, PROCESS__SETSCHED);
}

2839 2840 2841 2842 2843
static int selinux_task_getioprio(struct task_struct *p)
{
	return task_has_perm(current, p, PROCESS__GETSCHED);
}

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2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872
static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
{
	struct rlimit *old_rlim = current->signal->rlim + resource;
	int rc;

	rc = secondary_ops->task_setrlimit(resource, new_rlim);
	if (rc)
		return rc;

	/* 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
	   upon context transitions. See selinux_bprm_apply_creds. */
	if (old_rlim->rlim_max != new_rlim->rlim_max)
		return task_has_perm(current, current, PROCESS__SETRLIMIT);

	return 0;
}

static int selinux_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp)
{
	return task_has_perm(current, p, PROCESS__SETSCHED);
}

static int selinux_task_getscheduler(struct task_struct *p)
{
	return task_has_perm(current, p, PROCESS__GETSCHED);
}

2873 2874 2875 2876 2877
static int selinux_task_movememory(struct task_struct *p)
{
	return task_has_perm(current, p, PROCESS__SETSCHED);
}

2878 2879
static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
				int sig, u32 secid)
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2880 2881 2882
{
	u32 perm;
	int rc;
2883
	struct task_security_struct *tsec;
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2884

2885
	rc = secondary_ops->task_kill(p, info, sig, secid);
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2886 2887 2888
	if (rc)
		return rc;

2889
	if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
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2890 2891 2892 2893 2894 2895
		return 0;

	if (!sig)
		perm = PROCESS__SIGNULL; /* null signal; existence test */
	else
		perm = signal_to_av(sig);
2896 2897 2898 2899 2900 2901
	tsec = p->security;
	if (secid)
		rc = avc_has_perm(secid, tsec->sid, SECCLASS_PROCESS, perm, NULL);
	else
		rc = task_has_perm(current, p, perm);
	return rc;
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2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948
}

static int selinux_task_prctl(int option,
			      unsigned long arg2,
			      unsigned long arg3,
			      unsigned long arg4,
			      unsigned long arg5)
{
	/* The current prctl operations do not appear to require
	   any SELinux controls since they merely observe or modify
	   the state of the current process. */
	return 0;
}

static int selinux_task_wait(struct task_struct *p)
{
	u32 perm;

	perm = signal_to_av(p->exit_signal);

	return task_has_perm(p, current, perm);
}

static void selinux_task_reparent_to_init(struct task_struct *p)
{
  	struct task_security_struct *tsec;

	secondary_ops->task_reparent_to_init(p);

	tsec = p->security;
	tsec->osid = tsec->sid;
	tsec->sid = SECINITSID_KERNEL;
	return;
}

static void selinux_task_to_inode(struct task_struct *p,
				  struct inode *inode)
{
	struct task_security_struct *tsec = p->security;
	struct inode_security_struct *isec = inode->i_security;

	isec->sid = tsec->sid;
	isec->initialized = 1;
	return;
}

/* Returns error only if unable to parse addresses */
2949 2950
static int selinux_parse_skb_ipv4(struct sk_buff *skb,
			struct avc_audit_data *ad, u8 *proto)
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2951 2952 2953 2954
{
	int offset, ihlen, ret = -EINVAL;
	struct iphdr _iph, *ih;

2955
	offset = skb_network_offset(skb);
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2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967
	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
	if (ih == NULL)
		goto out;

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

	ad->u.net.v4info.saddr = ih->saddr;
	ad->u.net.v4info.daddr = ih->daddr;
	ret = 0;

2968 2969 2970
	if (proto)
		*proto = ih->protocol;

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2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003
	switch (ih->protocol) {
        case IPPROTO_TCP: {
        	struct tcphdr _tcph, *th;

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

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

		ad->u.net.sport = th->source;
		ad->u.net.dport = th->dest;
		break;
        }
        
        case IPPROTO_UDP: {
        	struct udphdr _udph, *uh;
        	
        	if (ntohs(ih->frag_off) & IP_OFFSET)
        		break;
        		
		offset += ihlen;
        	uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
		if (uh == NULL)
			break;	

        	ad->u.net.sport = uh->source;
        	ad->u.net.dport = uh->dest;
        	break;
        }

J
James Morris 已提交
3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019
	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;

		ad->u.net.sport = dh->dccph_sport;
		ad->u.net.dport = dh->dccph_dport;
		break;
        }

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3020 3021 3022 3023 3024 3025 3026 3027 3028 3029
        default:
        	break;
        }
out:
	return ret;
}

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

/* Returns error only if unable to parse addresses */
3030 3031
static int selinux_parse_skb_ipv6(struct sk_buff *skb,
			struct avc_audit_data *ad, u8 *proto)
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Linus Torvalds 已提交
3032 3033 3034 3035 3036
{
	u8 nexthdr;
	int ret = -EINVAL, offset;
	struct ipv6hdr _ipv6h, *ip6;

3037
	offset = skb_network_offset(skb);
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3038 3039 3040 3041 3042 3043 3044 3045 3046 3047
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		goto out;

	ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr);
	ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr);
	ret = 0;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
3048
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr);
L
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3049 3050 3051
	if (offset < 0)
		goto out;

3052 3053 3054
	if (proto)
		*proto = nexthdr;

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3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079
	switch (nexthdr) {
	case IPPROTO_TCP: {
        	struct tcphdr _tcph, *th;

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

		ad->u.net.sport = th->source;
		ad->u.net.dport = th->dest;
		break;
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

		ad->u.net.sport = uh->source;
		ad->u.net.dport = uh->dest;
		break;
	}

J
James Morris 已提交
3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

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

		ad->u.net.sport = dh->dccph_sport;
		ad->u.net.dport = dh->dccph_dport;
		break;
        }

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3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102
	/* includes fragments */
	default:
		break;
	}
out:
	return ret;
}

#endif /* IPV6 */

static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
3103
			     char **addrp, int *len, int src, u8 *proto)
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3104 3105 3106 3107 3108
{
	int ret = 0;

	switch (ad->u.net.family) {
	case PF_INET:
3109
		ret = selinux_parse_skb_ipv4(skb, ad, proto);
L
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3110 3111 3112 3113 3114 3115 3116 3117 3118
		if (ret || !addrp)
			break;
		*len = 4;
		*addrp = (char *)(src ? &ad->u.net.v4info.saddr :
					&ad->u.net.v4info.daddr);
		break;

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	case PF_INET6:
3119
		ret = selinux_parse_skb_ipv6(skb, ad, proto);
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3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133
		if (ret || !addrp)
			break;
		*len = 16;
		*addrp = (char *)(src ? &ad->u.net.v6info.saddr :
					&ad->u.net.v6info.daddr);
		break;
#endif	/* IPV6 */
	default:
		break;
	}

	return ret;
}

3134 3135 3136 3137 3138 3139 3140
/**
 * selinux_skb_extlbl_sid - Determine the external label of a packet
 * @skb: the packet
 * @sid: the packet's SID
 *
 * Description:
 * Check the various different forms of external packet labeling and determine
3141 3142 3143 3144 3145 3146
 * the external SID for the packet.  If only one form of external labeling is
 * present then it is used, if both labeled IPsec and NetLabel labels are
 * present then the SELinux type information is taken from the labeled IPsec
 * SA and the MLS sensitivity label information is taken from the NetLabel
 * security attributes.  This bit of "magic" is done in the call to
 * selinux_netlbl_skbuff_getsid().
3147 3148
 *
 */
3149
static void selinux_skb_extlbl_sid(struct sk_buff *skb, u32 *sid)
3150 3151 3152 3153 3154 3155 3156
{
	u32 xfrm_sid;
	u32 nlbl_sid;

	selinux_skb_xfrm_sid(skb, &xfrm_sid);
	if (selinux_netlbl_skbuff_getsid(skb,
					 (xfrm_sid == SECSID_NULL ?
3157
					  SECINITSID_NETMSG : xfrm_sid),
3158 3159 3160 3161 3162
					 &nlbl_sid) != 0)
		nlbl_sid = SECSID_NULL;
	*sid = (nlbl_sid == SECSID_NULL ? xfrm_sid : nlbl_sid);
}

L
Linus Torvalds 已提交
3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190
/* socket security operations */
static int socket_has_perm(struct task_struct *task, struct socket *sock,
			   u32 perms)
{
	struct inode_security_struct *isec;
	struct task_security_struct *tsec;
	struct avc_audit_data ad;
	int err = 0;

	tsec = task->security;
	isec = SOCK_INODE(sock)->i_security;

	if (isec->sid == SECINITSID_KERNEL)
		goto out;

	AVC_AUDIT_DATA_INIT(&ad,NET);
	ad.u.net.sk = sock->sk;
	err = avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad);

out:
	return err;
}

static int selinux_socket_create(int family, int type,
				 int protocol, int kern)
{
	int err = 0;
	struct task_security_struct *tsec;
3191
	u32 newsid;
L
Linus Torvalds 已提交
3192 3193 3194 3195 3196

	if (kern)
		goto out;

	tsec = current->security;
3197 3198
	newsid = tsec->sockcreate_sid ? : tsec->sid;
	err = avc_has_perm(tsec->sid, newsid,
L
Linus Torvalds 已提交
3199 3200 3201 3202 3203 3204 3205
			   socket_type_to_security_class(family, type,
			   protocol), SOCKET__CREATE, NULL);

out:
	return err;
}

V
Venkat Yekkirala 已提交
3206 3207
static int selinux_socket_post_create(struct socket *sock, int family,
				      int type, int protocol, int kern)
L
Linus Torvalds 已提交
3208
{
V
Venkat Yekkirala 已提交
3209
	int err = 0;
L
Linus Torvalds 已提交
3210 3211
	struct inode_security_struct *isec;
	struct task_security_struct *tsec;
3212
	struct sk_security_struct *sksec;
3213
	u32 newsid;
L
Linus Torvalds 已提交
3214 3215 3216 3217

	isec = SOCK_INODE(sock)->i_security;

	tsec = current->security;
3218
	newsid = tsec->sockcreate_sid ? : tsec->sid;
L
Linus Torvalds 已提交
3219
	isec->sclass = socket_type_to_security_class(family, type, protocol);
3220
	isec->sid = kern ? SECINITSID_KERNEL : newsid;
L
Linus Torvalds 已提交
3221 3222
	isec->initialized = 1;

3223 3224 3225
	if (sock->sk) {
		sksec = sock->sk->sk_security;
		sksec->sid = isec->sid;
P
Paul Moore 已提交
3226
		err = selinux_netlbl_socket_post_create(sock);
3227 3228
	}

V
Venkat Yekkirala 已提交
3229
	return err;
L
Linus Torvalds 已提交
3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246
}

/* 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)
{
	u16 family;
	int err;

	err = socket_has_perm(current, sock, SOCKET__BIND);
	if (err)
		goto out;

	/*
	 * If PF_INET or PF_INET6, check name_bind permission for the port.
3247 3248
	 * Multiple address binding for SCTP is not supported yet: we just
	 * check the first address now.
L
Linus Torvalds 已提交
3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276
	 */
	family = sock->sk->sk_family;
	if (family == PF_INET || family == PF_INET6) {
		char *addrp;
		struct inode_security_struct *isec;
		struct task_security_struct *tsec;
		struct avc_audit_data ad;
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
		struct sock *sk = sock->sk;
		u32 sid, node_perm, addrlen;

		tsec = current->security;
		isec = SOCK_INODE(sock)->i_security;

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

3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297
		if (snum) {
			int low, high;

			inet_get_local_port_range(&low, &high);

			if (snum < max(PROT_SOCK, low) || snum > high) {
				err = security_port_sid(sk->sk_family,
							sk->sk_type,
							sk->sk_protocol, snum,
							&sid);
				if (err)
					goto out;
				AVC_AUDIT_DATA_INIT(&ad,NET);
				ad.u.net.sport = htons(snum);
				ad.u.net.family = family;
				err = avc_has_perm(isec->sid, sid,
						   isec->sclass,
						   SOCKET__NAME_BIND, &ad);
				if (err)
					goto out;
			}
L
Linus Torvalds 已提交
3298 3299
		}
		
3300 3301
		switch(isec->sclass) {
		case SECCLASS_TCP_SOCKET:
L
Linus Torvalds 已提交
3302 3303 3304
			node_perm = TCP_SOCKET__NODE_BIND;
			break;
			
3305
		case SECCLASS_UDP_SOCKET:
L
Linus Torvalds 已提交
3306 3307
			node_perm = UDP_SOCKET__NODE_BIND;
			break;
J
James Morris 已提交
3308 3309 3310 3311 3312

		case SECCLASS_DCCP_SOCKET:
			node_perm = DCCP_SOCKET__NODE_BIND;
			break;

L
Linus Torvalds 已提交
3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349
		default:
			node_perm = RAWIP_SOCKET__NODE_BIND;
			break;
		}
		
		err = security_node_sid(family, addrp, addrlen, &sid);
		if (err)
			goto out;
		
		AVC_AUDIT_DATA_INIT(&ad,NET);
		ad.u.net.sport = htons(snum);
		ad.u.net.family = family;

		if (family == PF_INET)
			ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
		else
			ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr);

		err = avc_has_perm(isec->sid, sid,
		                   isec->sclass, node_perm, &ad);
		if (err)
			goto out;
	}
out:
	return err;
}

static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
{
	struct inode_security_struct *isec;
	int err;

	err = socket_has_perm(current, sock, SOCKET__CONNECT);
	if (err)
		return err;

	/*
J
James Morris 已提交
3350
	 * If a TCP or DCCP socket, check name_connect permission for the port.
L
Linus Torvalds 已提交
3351 3352
	 */
	isec = SOCK_INODE(sock)->i_security;
J
James Morris 已提交
3353 3354
	if (isec->sclass == SECCLASS_TCP_SOCKET ||
	    isec->sclass == SECCLASS_DCCP_SOCKET) {
L
Linus Torvalds 已提交
3355 3356 3357 3358 3359
		struct sock *sk = sock->sk;
		struct avc_audit_data ad;
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
J
James Morris 已提交
3360
		u32 sid, perm;
L
Linus Torvalds 已提交
3361 3362 3363

		if (sk->sk_family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
3364
			if (addrlen < sizeof(struct sockaddr_in))
L
Linus Torvalds 已提交
3365 3366 3367 3368
				return -EINVAL;
			snum = ntohs(addr4->sin_port);
		} else {
			addr6 = (struct sockaddr_in6 *)address;
3369
			if (addrlen < SIN6_LEN_RFC2133)
L
Linus Torvalds 已提交
3370 3371 3372 3373 3374 3375 3376 3377 3378
				return -EINVAL;
			snum = ntohs(addr6->sin6_port);
		}

		err = security_port_sid(sk->sk_family, sk->sk_type,
					sk->sk_protocol, snum, &sid);
		if (err)
			goto out;

J
James Morris 已提交
3379 3380 3381
		perm = (isec->sclass == SECCLASS_TCP_SOCKET) ?
		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;

L
Linus Torvalds 已提交
3382 3383 3384
		AVC_AUDIT_DATA_INIT(&ad,NET);
		ad.u.net.dport = htons(snum);
		ad.u.net.family = sk->sk_family;
J
James Morris 已提交
3385
		err = avc_has_perm(isec->sid, sid, isec->sclass, perm, &ad);
L
Linus Torvalds 已提交
3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421
		if (err)
			goto out;
	}

out:
	return err;
}

static int selinux_socket_listen(struct socket *sock, int backlog)
{
	return socket_has_perm(current, sock, SOCKET__LISTEN);
}

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

	err = socket_has_perm(current, sock, SOCKET__ACCEPT);
	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,
 				  int size)
{
V
Venkat Yekkirala 已提交
3422 3423 3424 3425 3426 3427 3428
	int rc;

	rc = socket_has_perm(current, sock, SOCKET__WRITE);
	if (rc)
		return rc;

	return selinux_netlbl_inode_permission(SOCK_INODE(sock), MAY_WRITE);
L
Linus Torvalds 已提交
3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448
}

static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
				  int size, int flags)
{
	return socket_has_perm(current, sock, SOCKET__READ);
}

static int selinux_socket_getsockname(struct socket *sock)
{
	return socket_has_perm(current, sock, SOCKET__GETATTR);
}

static int selinux_socket_getpeername(struct socket *sock)
{
	return socket_has_perm(current, sock, SOCKET__GETATTR);
}

static int selinux_socket_setsockopt(struct socket *sock,int level,int optname)
{
3449 3450 3451 3452 3453 3454 3455
	int err;

	err = socket_has_perm(current, sock, SOCKET__SETOPT);
	if (err)
		return err;

	return selinux_netlbl_socket_setsockopt(sock, level, optname);
L
Linus Torvalds 已提交
3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501
}

static int selinux_socket_getsockopt(struct socket *sock, int level,
				     int optname)
{
	return socket_has_perm(current, sock, SOCKET__GETOPT);
}

static int selinux_socket_shutdown(struct socket *sock, int how)
{
	return socket_has_perm(current, sock, SOCKET__SHUTDOWN);
}

static int selinux_socket_unix_stream_connect(struct socket *sock,
					      struct socket *other,
					      struct sock *newsk)
{
	struct sk_security_struct *ssec;
	struct inode_security_struct *isec;
	struct inode_security_struct *other_isec;
	struct avc_audit_data ad;
	int err;

	err = secondary_ops->unix_stream_connect(sock, other, newsk);
	if (err)
		return err;

	isec = SOCK_INODE(sock)->i_security;
	other_isec = SOCK_INODE(other)->i_security;

	AVC_AUDIT_DATA_INIT(&ad,NET);
	ad.u.net.sk = other->sk;

	err = avc_has_perm(isec->sid, other_isec->sid,
			   isec->sclass,
			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
	if (err)
		return err;

	/* connecting socket */
	ssec = sock->sk->sk_security;
	ssec->peer_sid = other_isec->sid;
	
	/* server child socket */
	ssec = newsk->sk_security;
	ssec->peer_sid = isec->sid;
3502 3503 3504
	err = security_sid_mls_copy(other_isec->sid, ssec->peer_sid, &ssec->sid);

	return err;
L
Linus Torvalds 已提交
3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528
}

static int selinux_socket_unix_may_send(struct socket *sock,
					struct socket *other)
{
	struct inode_security_struct *isec;
	struct inode_security_struct *other_isec;
	struct avc_audit_data ad;
	int err;

	isec = SOCK_INODE(sock)->i_security;
	other_isec = SOCK_INODE(other)->i_security;

	AVC_AUDIT_DATA_INIT(&ad,NET);
	ad.u.net.sk = other->sk;

	err = avc_has_perm(isec->sid, other_isec->sid,
			   isec->sclass, SOCKET__SENDTO, &ad);
	if (err)
		return err;

	return 0;
}

3529
static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
3530
		struct avc_audit_data *ad, u16 family, char *addrp, int len)
L
Linus Torvalds 已提交
3531
{
3532
	int err = 0;
L
Linus Torvalds 已提交
3533
	u32 netif_perm, node_perm, node_sid, if_sid, recv_perm = 0;
3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552
	struct socket *sock;
	u16 sock_class = 0;
	u32 sock_sid = 0;

 	read_lock_bh(&sk->sk_callback_lock);
 	sock = sk->sk_socket;
 	if (sock) {
 		struct inode *inode;
 		inode = SOCK_INODE(sock);
 		if (inode) {
 			struct inode_security_struct *isec;
 			isec = inode->i_security;
 			sock_sid = isec->sid;
 			sock_class = isec->sclass;
 		}
 	}
 	read_unlock_bh(&sk->sk_callback_lock);
 	if (!sock_sid)
  		goto out;
L
Linus Torvalds 已提交
3553

3554
	if (!skb->dev)
L
Linus Torvalds 已提交
3555 3556
		goto out;

3557
	err = sel_netif_sids(skb->dev, &if_sid, NULL);
L
Linus Torvalds 已提交
3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572
	if (err)
		goto out;

	switch (sock_class) {
	case SECCLASS_UDP_SOCKET:
		netif_perm = NETIF__UDP_RECV;
		node_perm = NODE__UDP_RECV;
		recv_perm = UDP_SOCKET__RECV_MSG;
		break;
	
	case SECCLASS_TCP_SOCKET:
		netif_perm = NETIF__TCP_RECV;
		node_perm = NODE__TCP_RECV;
		recv_perm = TCP_SOCKET__RECV_MSG;
		break;
J
James Morris 已提交
3573 3574 3575 3576 3577 3578 3579

	case SECCLASS_DCCP_SOCKET:
		netif_perm = NETIF__DCCP_RECV;
		node_perm = NODE__DCCP_RECV;
		recv_perm = DCCP_SOCKET__RECV_MSG;
		break;

L
Linus Torvalds 已提交
3580 3581 3582 3583 3584 3585
	default:
		netif_perm = NETIF__RAWIP_RECV;
		node_perm = NODE__RAWIP_RECV;
		break;
	}

3586
	err = avc_has_perm(sock_sid, if_sid, SECCLASS_NETIF, netif_perm, ad);
L
Linus Torvalds 已提交
3587 3588 3589 3590 3591 3592 3593
	if (err)
		goto out;
	
	err = security_node_sid(family, addrp, len, &node_sid);
	if (err)
		goto out;
	
3594
	err = avc_has_perm(sock_sid, node_sid, SECCLASS_NODE, node_perm, ad);
L
Linus Torvalds 已提交
3595 3596 3597 3598 3599 3600 3601
	if (err)
		goto out;

	if (recv_perm) {
		u32 port_sid;

		err = security_port_sid(sk->sk_family, sk->sk_type,
3602
		                        sk->sk_protocol, ntohs(ad->u.net.sport),
L
Linus Torvalds 已提交
3603 3604 3605 3606 3607
		                        &port_sid);
		if (err)
			goto out;

		err = avc_has_perm(sock_sid, port_sid,
3608
				   sock_class, recv_perm, ad);
L
Linus Torvalds 已提交
3609
	}
3610

3611 3612 3613 3614 3615 3616 3617 3618 3619 3620
out:
	return err;
}

static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
	u16 family;
	char *addrp;
	int len, err = 0;
	struct avc_audit_data ad;
3621
	struct sk_security_struct *sksec = sk->sk_security;
3622 3623 3624 3625 3626 3627

	family = sk->sk_family;
	if (family != PF_INET && family != PF_INET6)
		goto out;

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
A
Al Viro 已提交
3628
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3629 3630 3631 3632 3633 3634
		family = PF_INET;

	AVC_AUDIT_DATA_INIT(&ad, NET);
	ad.u.net.netif = skb->dev ? skb->dev->name : "[unknown]";
	ad.u.net.family = family;

3635
	err = selinux_parse_skb(skb, &ad, &addrp, &len, 1, NULL);
3636 3637 3638 3639
	if (err)
		goto out;

	if (selinux_compat_net)
3640
		err = selinux_sock_rcv_skb_compat(sk, skb, &ad, family,
3641 3642
						  addrp, len);
	else
3643
		err = avc_has_perm(sksec->sid, skb->secmark, SECCLASS_PACKET,
3644 3645 3646
				   PACKET__RECV, &ad);
	if (err)
		goto out;
3647

V
Venkat Yekkirala 已提交
3648 3649 3650 3651
	err = selinux_netlbl_sock_rcv_skb(sksec, skb, &ad);
	if (err)
		goto out;

3652
	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
L
Linus Torvalds 已提交
3653 3654 3655 3656
out:	
	return err;
}

C
Catherine Zhang 已提交
3657 3658
static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
					    int __user *optlen, unsigned len)
L
Linus Torvalds 已提交
3659 3660 3661 3662 3663 3664
{
	int err = 0;
	char *scontext;
	u32 scontext_len;
	struct sk_security_struct *ssec;
	struct inode_security_struct *isec;
3665
	u32 peer_sid = SECSID_NULL;
L
Linus Torvalds 已提交
3666 3667

	isec = SOCK_INODE(sock)->i_security;
C
Catherine Zhang 已提交
3668

3669 3670
	if (isec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
	    isec->sclass == SECCLASS_TCP_SOCKET) {
C
Catherine Zhang 已提交
3671 3672 3673
		ssec = sock->sk->sk_security;
		peer_sid = ssec->peer_sid;
	}
3674
	if (peer_sid == SECSID_NULL) {
L
Linus Torvalds 已提交
3675 3676 3677 3678
		err = -ENOPROTOOPT;
		goto out;
	}

C
Catherine Zhang 已提交
3679 3680
	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);

L
Linus Torvalds 已提交
3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700
	if (err)
		goto out;

	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);
out:	
	return err;
}

3701
static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
C
Catherine Zhang 已提交
3702
{
3703
	u32 peer_secid = SECSID_NULL;
C
Catherine Zhang 已提交
3704
	int err = 0;
C
Catherine Zhang 已提交
3705

3706
	if (sock && sock->sk->sk_family == PF_UNIX)
3707
		selinux_get_inode_sid(SOCK_INODE(sock), &peer_secid);
3708
	else if (skb)
3709
		selinux_skb_extlbl_sid(skb, &peer_secid);
C
Catherine Zhang 已提交
3710

3711 3712 3713
	if (peer_secid == SECSID_NULL)
		err = -EINVAL;
	*secid = peer_secid;
C
Catherine Zhang 已提交
3714

3715
	return err;
C
Catherine Zhang 已提交
3716 3717
}

A
Al Viro 已提交
3718
static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
L
Linus Torvalds 已提交
3719 3720 3721 3722 3723 3724 3725 3726 3727
{
	return sk_alloc_security(sk, family, priority);
}

static void selinux_sk_free_security(struct sock *sk)
{
	sk_free_security(sk);
}

3728
static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
3729
{
3730 3731
	struct sk_security_struct *ssec = sk->sk_security;
	struct sk_security_struct *newssec = newsk->sk_security;
3732

3733 3734
	newssec->sid = ssec->sid;
	newssec->peer_sid = ssec->peer_sid;
3735

P
Paul Moore 已提交
3736
	selinux_netlbl_sk_security_clone(ssec, newssec);
3737 3738
}

V
Venkat Yekkirala 已提交
3739
static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
3740
{
3741
	if (!sk)
V
Venkat Yekkirala 已提交
3742
		*secid = SECINITSID_ANY_SOCKET;
3743 3744
	else {
		struct sk_security_struct *sksec = sk->sk_security;
3745

V
Venkat Yekkirala 已提交
3746
		*secid = sksec->sid;
3747
	}
3748 3749
}

3750
static void selinux_sock_graft(struct sock* sk, struct socket *parent)
3751 3752 3753 3754
{
	struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
	struct sk_security_struct *sksec = sk->sk_security;

3755 3756 3757
	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
	    sk->sk_family == PF_UNIX)
		isec->sid = sksec->sid;
V
Venkat Yekkirala 已提交
3758 3759

	selinux_netlbl_sock_graft(sk, parent);
3760 3761
}

3762 3763
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				     struct request_sock *req)
3764 3765 3766
{
	struct sk_security_struct *sksec = sk->sk_security;
	int err;
V
Venkat Yekkirala 已提交
3767
	u32 newsid;
3768 3769
	u32 peersid;

3770
	selinux_skb_extlbl_sid(skb, &peersid);
3771 3772
	if (peersid == SECSID_NULL) {
		req->secid = sksec->sid;
3773
		req->peer_secid = SECSID_NULL;
3774 3775 3776
		return 0;
	}

3777 3778 3779 3780 3781
	err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
	if (err)
		return err;

	req->secid = newsid;
3782
	req->peer_secid = peersid;
3783 3784 3785
	return 0;
}

3786 3787
static void selinux_inet_csk_clone(struct sock *newsk,
				   const struct request_sock *req)
3788 3789 3790 3791
{
	struct sk_security_struct *newsksec = newsk->sk_security;

	newsksec->sid = req->secid;
3792
	newsksec->peer_sid = req->peer_secid;
3793 3794 3795 3796
	/* 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. */
3797

P
Paul Moore 已提交
3798 3799 3800
	/* We don't need to take any sort of lock here as we are the only
	 * thread with access to newsksec */
	selinux_netlbl_sk_security_reset(newsksec, req->rsk_ops->family);
3801 3802
}

3803 3804 3805 3806 3807
static void selinux_inet_conn_established(struct sock *sk,
				struct sk_buff *skb)
{
	struct sk_security_struct *sksec = sk->sk_security;

3808
	selinux_skb_extlbl_sid(skb, &sksec->peer_sid);
3809 3810
}

3811 3812
static void selinux_req_classify_flow(const struct request_sock *req,
				      struct flowi *fl)
3813 3814 3815 3816
{
	fl->secid = req->secid;
}

L
Linus Torvalds 已提交
3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828
static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
{
	int err = 0;
	u32 perm;
	struct nlmsghdr *nlh;
	struct socket *sock = sk->sk_socket;
	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
	
	if (skb->len < NLMSG_SPACE(0)) {
		err = -EINVAL;
		goto out;
	}
3829
	nlh = nlmsg_hdr(skb);
L
Linus Torvalds 已提交
3830 3831 3832 3833
	
	err = selinux_nlmsg_lookup(isec->sclass, nlh->nlmsg_type, &perm);
	if (err) {
		if (err == -EINVAL) {
3834
			audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
L
Linus Torvalds 已提交
3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854
				  "SELinux:  unrecognized netlink message"
				  " type=%hu for sclass=%hu\n",
				  nlh->nlmsg_type, isec->sclass);
			if (!selinux_enforcing)
				err = 0;
		}

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

	err = socket_has_perm(current, sock, perm);
out:
	return err;
}

#ifdef CONFIG_NETFILTER

3855 3856 3857
static int selinux_ip_postroute_last_compat(struct sock *sk, struct net_device *dev,
					    struct avc_audit_data *ad,
					    u16 family, char *addrp, int len)
L
Linus Torvalds 已提交
3858
{
3859
	int err = 0;
L
Linus Torvalds 已提交
3860
	u32 netif_perm, node_perm, node_sid, if_sid, send_perm = 0;
3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873
	struct socket *sock;
	struct inode *inode;
	struct inode_security_struct *isec;

	sock = sk->sk_socket;
	if (!sock)
		goto out;

	inode = SOCK_INODE(sock);
	if (!inode)
		goto out;

	isec = inode->i_security;
L
Linus Torvalds 已提交
3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890
	
	err = sel_netif_sids(dev, &if_sid, NULL);
	if (err)
		goto out;

	switch (isec->sclass) {
	case SECCLASS_UDP_SOCKET:
		netif_perm = NETIF__UDP_SEND;
		node_perm = NODE__UDP_SEND;
		send_perm = UDP_SOCKET__SEND_MSG;
		break;
	
	case SECCLASS_TCP_SOCKET:
		netif_perm = NETIF__TCP_SEND;
		node_perm = NODE__TCP_SEND;
		send_perm = TCP_SOCKET__SEND_MSG;
		break;
J
James Morris 已提交
3891 3892 3893 3894 3895 3896 3897

	case SECCLASS_DCCP_SOCKET:
		netif_perm = NETIF__DCCP_SEND;
		node_perm = NODE__DCCP_SEND;
		send_perm = DCCP_SOCKET__SEND_MSG;
		break;

L
Linus Torvalds 已提交
3898 3899 3900 3901 3902 3903
	default:
		netif_perm = NETIF__RAWIP_SEND;
		node_perm = NODE__RAWIP_SEND;
		break;
	}

3904 3905
	err = avc_has_perm(isec->sid, if_sid, SECCLASS_NETIF, netif_perm, ad);
	if (err)
L
Linus Torvalds 已提交
3906 3907
		goto out;
		
3908 3909
	err = security_node_sid(family, addrp, len, &node_sid);
	if (err)
L
Linus Torvalds 已提交
3910 3911
		goto out;
	
3912 3913
	err = avc_has_perm(isec->sid, node_sid, SECCLASS_NODE, node_perm, ad);
	if (err)
L
Linus Torvalds 已提交
3914 3915 3916 3917 3918 3919 3920 3921
		goto out;

	if (send_perm) {
		u32 port_sid;
		
		err = security_port_sid(sk->sk_family,
		                        sk->sk_type,
		                        sk->sk_protocol,
3922 3923 3924
		                        ntohs(ad->u.net.dport),
		                        &port_sid);
		if (err)
L
Linus Torvalds 已提交
3925 3926 3927
			goto out;

		err = avc_has_perm(isec->sid, port_sid, isec->sclass,
3928
				   send_perm, ad);
L
Linus Torvalds 已提交
3929
	}
3930 3931 3932 3933 3934
out:
	return err;
}

static unsigned int selinux_ip_postroute_last(unsigned int hooknum,
3935
                                              struct sk_buff *skb,
3936 3937 3938 3939 3940 3941 3942 3943 3944 3945
                                              const struct net_device *in,
                                              const struct net_device *out,
                                              int (*okfn)(struct sk_buff *),
                                              u16 family)
{
	char *addrp;
	int len, err = 0;
	struct sock *sk;
	struct avc_audit_data ad;
	struct net_device *dev = (struct net_device *)out;
3946
	struct sk_security_struct *sksec;
3947
	u8 proto;
L
Linus Torvalds 已提交
3948

3949 3950
	sk = skb->sk;
	if (!sk)
3951 3952
		goto out;

3953
	sksec = sk->sk_security;
3954 3955 3956 3957 3958

	AVC_AUDIT_DATA_INIT(&ad, NET);
	ad.u.net.netif = dev->name;
	ad.u.net.family = family;

3959
	err = selinux_parse_skb(skb, &ad, &addrp, &len, 0, &proto);
3960 3961 3962 3963
	if (err)
		goto out;

	if (selinux_compat_net)
3964
		err = selinux_ip_postroute_last_compat(sk, dev, &ad,
3965 3966
						       family, addrp, len);
	else
3967
		err = avc_has_perm(sksec->sid, skb->secmark, SECCLASS_PACKET,
3968
				   PACKET__SEND, &ad);
3969

3970 3971 3972
	if (err)
		goto out;

3973
	err = selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto);
L
Linus Torvalds 已提交
3974
out:
3975
	return err ? NF_DROP : NF_ACCEPT;
L
Linus Torvalds 已提交
3976 3977 3978
}

static unsigned int selinux_ipv4_postroute_last(unsigned int hooknum,
3979
						struct sk_buff *skb,
L
Linus Torvalds 已提交
3980 3981 3982 3983
						const struct net_device *in,
						const struct net_device *out,
						int (*okfn)(struct sk_buff *))
{
3984
	return selinux_ip_postroute_last(hooknum, skb, in, out, okfn, PF_INET);
L
Linus Torvalds 已提交
3985 3986 3987 3988 3989
}

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

static unsigned int selinux_ipv6_postroute_last(unsigned int hooknum,
3990
						struct sk_buff *skb,
L
Linus Torvalds 已提交
3991 3992 3993 3994
						const struct net_device *in,
						const struct net_device *out,
						int (*okfn)(struct sk_buff *))
{
3995
	return selinux_ip_postroute_last(hooknum, skb, in, out, okfn, PF_INET6);
L
Linus Torvalds 已提交
3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015
}

#endif	/* IPV6 */

#endif	/* CONFIG_NETFILTER */

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

	err = secondary_ops->netlink_send(sk, skb);
	if (err)
		return err;

	if (policydb_loaded_version >= POLICYDB_VERSION_NLCLASS)
		err = selinux_nlmsg_perm(sk, skb);

	return err;
}

4016
static int selinux_netlink_recv(struct sk_buff *skb, int capability)
L
Linus Torvalds 已提交
4017
{
4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029
	int err;
	struct avc_audit_data ad;

	err = secondary_ops->netlink_recv(skb, capability);
	if (err)
		return err;

	AVC_AUDIT_DATA_INIT(&ad, CAP);
	ad.u.cap = capability;

	return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid,
	                    SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad);
L
Linus Torvalds 已提交
4030 4031 4032 4033 4034 4035 4036 4037 4038
}

static int ipc_alloc_security(struct task_struct *task,
			      struct kern_ipc_perm *perm,
			      u16 sclass)
{
	struct task_security_struct *tsec = task->security;
	struct ipc_security_struct *isec;

J
James Morris 已提交
4039
	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
4040 4041 4042 4043 4044
	if (!isec)
		return -ENOMEM;

	isec->sclass = sclass;
	isec->ipc_perm = perm;
4045
	isec->sid = tsec->sid;
L
Linus Torvalds 已提交
4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061
	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
4062
	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081
	if (!msec)
		return -ENOMEM;

	msec->msg = msg;
	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,
4082
			u32 perms)
L
Linus Torvalds 已提交
4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093
{
	struct task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct avc_audit_data ad;

	tsec = current->security;
	isec = ipc_perms->security;

	AVC_AUDIT_DATA_INIT(&ad, IPC);
	ad.u.ipc_id = ipc_perms->key;

4094
	return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, &ad);
L
Linus Torvalds 已提交
4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178
}

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 task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct avc_audit_data ad;
	int rc;

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

	tsec = current->security;
	isec = msq->q_perm.security;

	AVC_AUDIT_DATA_INIT(&ad, IPC);
 	ad.u.ipc_id = msq->q_perm.key;

	rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
			  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 task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct avc_audit_data ad;

	tsec = current->security;
	isec = msq->q_perm.security;

	AVC_AUDIT_DATA_INIT(&ad, IPC);
	ad.u.ipc_id = msq->q_perm.key;

	return avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
			    MSGQ__ASSOCIATE, &ad);
}

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

	switch(cmd) {
	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;
	}

4179
	err = ipc_has_perm(&msq->q_perm, perms);
L
Linus Torvalds 已提交
4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267 4268 4269 4270 4271 4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 4295 4296 4297 4298 4299 4300 4301 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330
	return err;
}

static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
{
	struct task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct msg_security_struct *msec;
	struct avc_audit_data ad;
	int rc;

	tsec = current->security;
	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
		 */
		rc = security_transition_sid(tsec->sid,
					     isec->sid,
					     SECCLASS_MSG,
					     &msec->sid);
		if (rc)
			return rc;
	}

	AVC_AUDIT_DATA_INIT(&ad, IPC);
	ad.u.ipc_id = msq->q_perm.key;

	/* Can this process write to the queue? */
	rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_MSGQ,
			  MSGQ__WRITE, &ad);
	if (!rc)
		/* Can this process send the message */
		rc = avc_has_perm(tsec->sid, msec->sid,
				  SECCLASS_MSG, MSG__SEND, &ad);
	if (!rc)
		/* Can the message be put in the queue? */
		rc = avc_has_perm(msec->sid, isec->sid,
				  SECCLASS_MSGQ, MSGQ__ENQUEUE, &ad);

	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 task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct msg_security_struct *msec;
	struct avc_audit_data ad;
	int rc;

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

	AVC_AUDIT_DATA_INIT(&ad, IPC);
 	ad.u.ipc_id = msq->q_perm.key;

	rc = avc_has_perm(tsec->sid, isec->sid,
			  SECCLASS_MSGQ, MSGQ__READ, &ad);
	if (!rc)
		rc = avc_has_perm(tsec->sid, msec->sid,
				  SECCLASS_MSG, MSG__RECEIVE, &ad);
	return rc;
}

/* Shared Memory security operations */
static int selinux_shm_alloc_security(struct shmid_kernel *shp)
{
	struct task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct avc_audit_data ad;
	int rc;

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

	tsec = current->security;
	isec = shp->shm_perm.security;

	AVC_AUDIT_DATA_INIT(&ad, IPC);
 	ad.u.ipc_id = shp->shm_perm.key;

	rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_SHM,
			  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 task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct avc_audit_data ad;

	tsec = current->security;
	isec = shp->shm_perm.security;

	AVC_AUDIT_DATA_INIT(&ad, IPC);
	ad.u.ipc_id = shp->shm_perm.key;

	return avc_has_perm(tsec->sid, isec->sid, SECCLASS_SHM,
			    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;

	switch(cmd) {
	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;
	}

4331
	err = ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
4332 4333 4334 4335 4336 4337 4338 4339 4340 4341 4342 4343 4344 4345 4346 4347 4348 4349
	return err;
}

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

	rc = secondary_ops->shm_shmat(shp, shmaddr, shmflg);
	if (rc)
		return rc;

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

4350
	return ipc_has_perm(&shp->shm_perm, perms);
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}

/* Semaphore security operations */
static int selinux_sem_alloc_security(struct sem_array *sma)
{
	struct task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct avc_audit_data ad;
	int rc;

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

	tsec = current->security;
	isec = sma->sem_perm.security;

	AVC_AUDIT_DATA_INIT(&ad, IPC);
 	ad.u.ipc_id = sma->sem_perm.key;

	rc = avc_has_perm(tsec->sid, isec->sid, SECCLASS_SEM,
			  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 task_security_struct *tsec;
	struct ipc_security_struct *isec;
	struct avc_audit_data ad;

	tsec = current->security;
	isec = sma->sem_perm.security;

	AVC_AUDIT_DATA_INIT(&ad, IPC);
	ad.u.ipc_id = sma->sem_perm.key;

	return avc_has_perm(tsec->sid, isec->sid, SECCLASS_SEM,
			    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;

	switch(cmd) {
	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;
	}

4439
	err = ipc_has_perm(&sma->sem_perm, perms);
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	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;

4453
	return ipc_has_perm(&sma->sem_perm, perms);
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}

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;

4469
	return ipc_has_perm(ipcp, av);
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}

/* module stacking operations */
static int selinux_register_security (const char *name, struct security_operations *ops)
{
	if (secondary_ops != original_ops) {
4476
		printk(KERN_ERR "%s:  There is already a secondary security "
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		       "module registered.\n", __FUNCTION__);
		return -EINVAL;
 	}

	secondary_ops = ops;

	printk(KERN_INFO "%s:  Registering secondary module %s\n",
	       __FUNCTION__,
	       name);

	return 0;
}

static int selinux_unregister_security (const char *name, struct security_operations *ops)
{
	if (ops != secondary_ops) {
4493
		printk(KERN_ERR "%s:  trying to unregister a security module "
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		        "that is not registered.\n", __FUNCTION__);
		return -EINVAL;
	}

	secondary_ops = original_ops;

	return 0;
}

static void selinux_d_instantiate (struct dentry *dentry, struct inode *inode)
{
	if (inode)
		inode_doinit_with_dentry(inode, dentry);
}

static int selinux_getprocattr(struct task_struct *p,
4510
			       char *name, char **value)
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{
	struct task_security_struct *tsec;
4513
	u32 sid;
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	int error;
4515
	unsigned len;
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	if (current != p) {
		error = task_has_perm(current, p, PROCESS__GETATTR);
		if (error)
			return error;
	}

	tsec = p->security;

	if (!strcmp(name, "current"))
		sid = tsec->sid;
	else if (!strcmp(name, "prev"))
		sid = tsec->osid;
	else if (!strcmp(name, "exec"))
		sid = tsec->exec_sid;
	else if (!strcmp(name, "fscreate"))
		sid = tsec->create_sid;
4533 4534
	else if (!strcmp(name, "keycreate"))
		sid = tsec->keycreate_sid;
4535 4536
	else if (!strcmp(name, "sockcreate"))
		sid = tsec->sockcreate_sid;
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	else
		return -EINVAL;

	if (!sid)
		return 0;

4543 4544 4545 4546
	error = security_sid_to_context(sid, value, &len);
	if (error)
		return error;
	return len;
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}

static int selinux_setprocattr(struct task_struct *p,
			       char *name, void *value, size_t size)
{
	struct task_security_struct *tsec;
	u32 sid = 0;
	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"))
		error = task_has_perm(current, p, PROCESS__SETEXEC);
	else if (!strcmp(name, "fscreate"))
		error = task_has_perm(current, p, PROCESS__SETFSCREATE);
4572 4573
	else if (!strcmp(name, "keycreate"))
		error = task_has_perm(current, p, PROCESS__SETKEYCREATE);
4574 4575
	else if (!strcmp(name, "sockcreate"))
		error = task_has_perm(current, p, PROCESS__SETSOCKCREATE);
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	else if (!strcmp(name, "current"))
		error = task_has_perm(current, p, PROCESS__SETCURRENT);
	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);
		if (error)
			return error;
	}

	/* Permission checking based on the specified context is
	   performed during the actual operation (execve,
	   open/mkdir/...), when we know the full context of the
	   operation.  See selinux_bprm_set_security for the execve
	   checks and may_create for the file creation checks. The
	   operation will then fail if the context is not permitted. */
	tsec = p->security;
	if (!strcmp(name, "exec"))
		tsec->exec_sid = sid;
	else if (!strcmp(name, "fscreate"))
		tsec->create_sid = sid;
4605 4606 4607 4608 4609
	else if (!strcmp(name, "keycreate")) {
		error = may_create_key(sid, p);
		if (error)
			return error;
		tsec->keycreate_sid = sid;
4610 4611 4612
	} else if (!strcmp(name, "sockcreate"))
		tsec->sockcreate_sid = sid;
	else if (!strcmp(name, "current")) {
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		struct av_decision avd;

		if (sid == 0)
			return -EINVAL;

		/* Only allow single threaded processes to change context */
		if (atomic_read(&p->mm->mm_users) != 1) {
			struct task_struct *g, *t;
			struct mm_struct *mm = p->mm;
			read_lock(&tasklist_lock);
			do_each_thread(g, t)
				if (t->mm == mm && t != p) {
					read_unlock(&tasklist_lock);
					return -EPERM;
				}
			while_each_thread(g, t);
			read_unlock(&tasklist_lock);
                }

		/* Check permissions for the transition. */
		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
		                     PROCESS__DYNTRANSITION, NULL);
		if (error)
			return error;

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and fail. */
		task_lock(p);
		if (p->ptrace & PT_PTRACED) {
			error = avc_has_perm_noaudit(tsec->ptrace_sid, sid,
						     SECCLASS_PROCESS,
4644
						     PROCESS__PTRACE, 0, &avd);
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			if (!error)
				tsec->sid = sid;
			task_unlock(p);
			avc_audit(tsec->ptrace_sid, sid, SECCLASS_PROCESS,
				  PROCESS__PTRACE, &avd, error, NULL);
			if (error)
				return error;
		} else {
			tsec->sid = sid;
			task_unlock(p);
		}
	}
	else
		return -EINVAL;

	return size;
}

4663 4664 4665 4666 4667 4668 4669
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
	return security_sid_to_context(secid, secdata, seclen);
}

static void selinux_release_secctx(char *secdata, u32 seclen)
{
4670
	kfree(secdata);
4671 4672
}

4673 4674
#ifdef CONFIG_KEYS

4675 4676
static int selinux_key_alloc(struct key *k, struct task_struct *tsk,
			     unsigned long flags)
4677 4678 4679 4680 4681 4682 4683 4684 4685
{
	struct task_security_struct *tsec = tsk->security;
	struct key_security_struct *ksec;

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

	ksec->obj = k;
4686 4687 4688 4689
	if (tsec->keycreate_sid)
		ksec->sid = tsec->keycreate_sid;
	else
		ksec->sid = tsec->sid;
4690 4691 4692 4693 4694 4695 4696 4697 4698 4699 4700 4701 4702 4703 4704 4705 4706 4707 4708 4709 4710 4711 4712 4713 4714 4715 4716 4717 4718 4719 4720 4721 4722 4723 4724 4725 4726 4727
	k->security = ksec;

	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,
			    struct task_struct *ctx,
			    key_perm_t perm)
{
	struct key *key;
	struct task_security_struct *tsec;
	struct key_security_struct *ksec;

	key = key_ref_to_ptr(key_ref);

	tsec = ctx->security;
	ksec = key->security;

	/* 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;

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

#endif

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static struct security_operations selinux_ops = {
	.ptrace =			selinux_ptrace,
	.capget =			selinux_capget,
	.capset_check =			selinux_capset_check,
	.capset_set =			selinux_capset_set,
	.sysctl =			selinux_sysctl,
	.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,
        .netlink_recv =			selinux_netlink_recv,

	.bprm_alloc_security =		selinux_bprm_alloc_security,
	.bprm_free_security =		selinux_bprm_free_security,
	.bprm_apply_creds =		selinux_bprm_apply_creds,
	.bprm_post_apply_creds =	selinux_bprm_post_apply_creds,
	.bprm_set_security =		selinux_bprm_set_security,
	.bprm_check_security =		selinux_bprm_check_security,
	.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,
	.sb_kern_mount =	        selinux_sb_kern_mount,
	.sb_statfs =			selinux_sb_statfs,
	.sb_mount =			selinux_mount,
	.sb_umount =			selinux_umount,

	.inode_alloc_security =		selinux_inode_alloc_security,
	.inode_free_security =		selinux_inode_free_security,
4761
	.inode_init_security =		selinux_inode_init_security,
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	.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,
4780
	.inode_xattr_getsuffix =        selinux_inode_xattr_getsuffix,
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	.inode_getsecurity =            selinux_inode_getsecurity,
	.inode_setsecurity =            selinux_inode_setsecurity,
	.inode_listsecurity =           selinux_inode_listsecurity,

	.file_permission =		selinux_file_permission,
	.file_alloc_security =		selinux_file_alloc_security,
	.file_free_security =		selinux_file_free_security,
	.file_ioctl =			selinux_file_ioctl,
	.file_mmap =			selinux_file_mmap,
	.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,

	.task_create =			selinux_task_create,
	.task_alloc_security =		selinux_task_alloc_security,
	.task_free_security =		selinux_task_free_security,
	.task_setuid =			selinux_task_setuid,
	.task_post_setuid =		selinux_task_post_setuid,
	.task_setgid =			selinux_task_setgid,
	.task_setpgid =			selinux_task_setpgid,
	.task_getpgid =			selinux_task_getpgid,
	.task_getsid =		        selinux_task_getsid,
4806
	.task_getsecid =		selinux_task_getsecid,
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	.task_setgroups =		selinux_task_setgroups,
	.task_setnice =			selinux_task_setnice,
4809
	.task_setioprio =		selinux_task_setioprio,
4810
	.task_getioprio =		selinux_task_getioprio,
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	.task_setrlimit =		selinux_task_setrlimit,
	.task_setscheduler =		selinux_task_setscheduler,
	.task_getscheduler =		selinux_task_getscheduler,
4814
	.task_movememory =		selinux_task_movememory,
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	.task_kill =			selinux_task_kill,
	.task_wait =			selinux_task_wait,
	.task_prctl =			selinux_task_prctl,
	.task_reparent_to_init =	selinux_task_reparent_to_init,
	.task_to_inode =                selinux_task_to_inode,

	.ipc_permission =		selinux_ipc_permission,

	.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,

	.sem_alloc_security = 		selinux_sem_alloc_security,
	.sem_free_security =  		selinux_sem_free_security,
	.sem_associate =		selinux_sem_associate,
	.sem_semctl =			selinux_sem_semctl,
	.sem_semop =			selinux_sem_semop,

	.register_security =		selinux_register_security,
	.unregister_security =		selinux_unregister_security,

	.d_instantiate =                selinux_d_instantiate,

	.getprocattr =                  selinux_getprocattr,
	.setprocattr =                  selinux_setprocattr,

4853 4854 4855
	.secid_to_secctx =		selinux_secid_to_secctx,
	.release_secctx =		selinux_release_secctx,

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        .unix_stream_connect =		selinux_socket_unix_stream_connect,
	.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,
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	.socket_getpeersec_stream =	selinux_socket_getpeersec_stream,
	.socket_getpeersec_dgram =	selinux_socket_getpeersec_dgram,
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	.sk_alloc_security =		selinux_sk_alloc_security,
	.sk_free_security =		selinux_sk_free_security,
4877
	.sk_clone_security =		selinux_sk_clone_security,
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Venkat Yekkirala 已提交
4878
	.sk_getsecid = 			selinux_sk_getsecid,
4879 4880 4881
	.sock_graft =			selinux_sock_graft,
	.inet_conn_request =		selinux_inet_conn_request,
	.inet_csk_clone =		selinux_inet_csk_clone,
4882
	.inet_conn_established =	selinux_inet_conn_established,
4883
	.req_classify_flow =		selinux_req_classify_flow,
4884 4885 4886 4887 4888

#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,
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	.xfrm_policy_delete_security =	selinux_xfrm_policy_delete,
4890 4891
	.xfrm_state_alloc_security =	selinux_xfrm_state_alloc,
	.xfrm_state_free_security =	selinux_xfrm_state_free,
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	.xfrm_state_delete_security =	selinux_xfrm_state_delete,
4893
	.xfrm_policy_lookup = 		selinux_xfrm_policy_lookup,
4894 4895
	.xfrm_state_pol_flow_match =	selinux_xfrm_state_pol_flow_match,
	.xfrm_decode_session =		selinux_xfrm_decode_session,
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#endif
4897 4898 4899 4900 4901 4902

#ifdef CONFIG_KEYS
	.key_alloc =                    selinux_key_alloc,
	.key_free =                     selinux_key_free,
	.key_permission =               selinux_key_permission,
#endif
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};

static __init int selinux_init(void)
{
	struct task_security_struct *tsec;

	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. */
	if (task_alloc_security(current))
		panic("SELinux:  Failed to initialize initial task.\n");
	tsec = current->security;
	tsec->osid = tsec->sid = SECINITSID_KERNEL;

4922 4923
	sel_inode_cache = kmem_cache_create("selinux_inode_security",
					    sizeof(struct inode_security_struct),
4924
					    0, SLAB_PANIC, NULL);
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	avc_init();

	original_ops = secondary_ops = security_ops;
	if (!secondary_ops)
		panic ("SELinux: No initial security operations\n");
	if (register_security (&selinux_ops))
		panic("SELinux: Unable to register with kernel.\n");

	if (selinux_enforcing) {
4934
		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
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	} else {
4936
		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
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	}
4938 4939 4940

#ifdef CONFIG_KEYS
	/* Add security information to initial keyrings */
4941 4942 4943 4944
	selinux_key_alloc(&root_user_keyring, current,
			  KEY_ALLOC_NOT_IN_QUOTA);
	selinux_key_alloc(&root_session_keyring, current,
			  KEY_ALLOC_NOT_IN_QUOTA);
4945 4946
#endif

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	return 0;
}

void selinux_complete_init(void)
{
4952
	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
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	/* Set up any superblocks initialized prior to the policy load. */
4955
	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
4956
	spin_lock(&sb_lock);
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	spin_lock(&sb_security_lock);
next_sb:
	if (!list_empty(&superblock_security_head)) {
		struct superblock_security_struct *sbsec =
				list_entry(superblock_security_head.next,
				           struct superblock_security_struct,
				           list);
		struct super_block *sb = sbsec->sb;
		sb->s_count++;
		spin_unlock(&sb_security_lock);
4967
		spin_unlock(&sb_lock);
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		down_read(&sb->s_umount);
		if (sb->s_root)
			superblock_doinit(sb, NULL);
		drop_super(sb);
4972
		spin_lock(&sb_lock);
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		spin_lock(&sb_security_lock);
		list_del_init(&sbsec->list);
		goto next_sb;
	}
	spin_unlock(&sb_security_lock);
4978
	spin_unlock(&sb_lock);
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}

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

4985
#if defined(CONFIG_NETFILTER)
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static struct nf_hook_ops selinux_ipv4_op = {
	.hook =		selinux_ipv4_postroute_last,
	.owner =	THIS_MODULE,
	.pf =		PF_INET,
	.hooknum =	NF_IP_POST_ROUTING,
	.priority =	NF_IP_PRI_SELINUX_LAST,
};

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

static struct nf_hook_ops selinux_ipv6_op = {
	.hook =		selinux_ipv6_postroute_last,
	.owner =	THIS_MODULE,
	.pf =		PF_INET6,
	.hooknum =	NF_IP6_POST_ROUTING,
	.priority =	NF_IP6_PRI_SELINUX_LAST,
};

#endif	/* IPV6 */

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

	if (!selinux_enabled)
		goto out;
5013 5014 5015

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

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	err = nf_register_hook(&selinux_ipv4_op);
	if (err)
		panic("SELinux: nf_register_hook for IPv4: error %d\n", err);

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

	err = nf_register_hook(&selinux_ipv6_op);
	if (err)
		panic("SELinux: nf_register_hook for IPv6: error %d\n", err);

#endif	/* IPV6 */
5027

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out:
	return err;
}

__initcall(selinux_nf_ip_init);

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static void selinux_nf_ip_exit(void)
{
5037
	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
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	nf_unregister_hook(&selinux_ipv4_op);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	nf_unregister_hook(&selinux_ipv6_op);
#endif	/* IPV6 */
}
#endif

5046
#else /* CONFIG_NETFILTER */
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#ifdef CONFIG_SECURITY_SELINUX_DISABLE
#define selinux_nf_ip_exit()
#endif

5052
#endif /* CONFIG_NETFILTER */
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#ifdef CONFIG_SECURITY_SELINUX_DISABLE
int selinux_disable(void)
{
	extern void exit_sel_fs(void);
	static int selinux_disabled = 0;

	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;
5073
	selinux_enabled = 0;
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	/* Reset security_ops to the secondary module, dummy or capability. */
	security_ops = secondary_ops;

	/* Unregister netfilter hooks. */
	selinux_nf_ip_exit();

	/* Unregister selinuxfs. */
	exit_sel_fs();

	return 0;
}
#endif