hooks.c 163.5 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6
/*
 *  NSA Security-Enhanced Linux (SELinux) security module
 *
 *  This file contains the SELinux hook function implementations.
 *
 *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
7 8 9
 *	      Chris Vance, <cvance@nai.com>
 *	      Wayne Salamon, <wsalamon@nai.com>
 *	      James Morris <jmorris@redhat.com>
L
Linus Torvalds 已提交
10 11
 *
 *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12 13
 *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
 *					   Eric Paris <eparis@redhat.com>
L
Linus Torvalds 已提交
14
 *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
15
 *			    <dgoeddel@trustedcs.com>
16
 *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
17
 *	Paul Moore <paul@paul-moore.com>
18
 *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
19
 *		       Yuichi Nakamura <ynakam@hitachisoft.jp>
L
Linus Torvalds 已提交
20 21 22
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License version 2,
23
 *	as published by the Free Software Foundation.
L
Linus Torvalds 已提交
24 25 26
 */

#include <linux/init.h>
27
#include <linux/kd.h>
L
Linus Torvalds 已提交
28
#include <linux/kernel.h>
29
#include <linux/tracehook.h>
L
Linus Torvalds 已提交
30
#include <linux/errno.h>
31
#include <linux/sched/signal.h>
C
Casey Schaufler 已提交
32
#include <linux/lsm_hooks.h>
L
Linus Torvalds 已提交
33 34 35 36 37 38 39
#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>
40
#include <linux/proc_fs.h>
L
Linus Torvalds 已提交
41 42 43
#include <linux/swap.h>
#include <linux/spinlock.h>
#include <linux/syscalls.h>
44
#include <linux/dcache.h>
L
Linus Torvalds 已提交
45
#include <linux/file.h>
A
Al Viro 已提交
46
#include <linux/fdtable.h>
L
Linus Torvalds 已提交
47 48 49 50 51 52
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/netfilter_ipv4.h>
#include <linux/netfilter_ipv6.h>
#include <linux/tty.h>
#include <net/icmp.h>
53
#include <net/ip.h>		/* for local_port_range[] */
L
Linus Torvalds 已提交
54
#include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
55
#include <net/inet_connection_sock.h>
56
#include <net/net_namespace.h>
57
#include <net/netlabel.h>
58
#include <linux/uaccess.h>
L
Linus Torvalds 已提交
59
#include <asm/ioctls.h>
A
Arun Sharma 已提交
60
#include <linux/atomic.h>
L
Linus Torvalds 已提交
61 62 63
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>	/* for network interface checks */
64
#include <net/netlink.h>
L
Linus Torvalds 已提交
65 66
#include <linux/tcp.h>
#include <linux/udp.h>
J
James Morris 已提交
67
#include <linux/dccp.h>
L
Linus Torvalds 已提交
68 69 70 71 72 73 74 75 76
#include <linux/quota.h>
#include <linux/un.h>		/* for Unix socket types */
#include <net/af_unix.h>	/* for Unix socket types */
#include <linux/parser.h>
#include <linux/nfs_mount.h>
#include <net/ipv6.h>
#include <linux/hugetlb.h>
#include <linux/personality.h>
#include <linux/audit.h>
77
#include <linux/string.h>
C
Catherine Zhang 已提交
78
#include <linux/selinux.h>
79
#include <linux/mutex.h>
80
#include <linux/posix-timers.h>
81
#include <linux/syslog.h>
82
#include <linux/user_namespace.h>
83
#include <linux/export.h>
A
Al Viro 已提交
84 85
#include <linux/msg.h>
#include <linux/shm.h>
L
Linus Torvalds 已提交
86 87 88 89

#include "avc.h"
#include "objsec.h"
#include "netif.h"
90
#include "netnode.h"
P
Paul Moore 已提交
91
#include "netport.h"
92
#include "xfrm.h"
93
#include "netlabel.h"
94
#include "audit.h"
95
#include "avc_ss.h"
L
Linus Torvalds 已提交
96

97
/* SECMARK reference count */
98
static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
99

L
Linus Torvalds 已提交
100
#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
101
int selinux_enforcing;
L
Linus Torvalds 已提交
102 103 104

static int __init enforcing_setup(char *str)
{
105
	unsigned long enforcing;
106
	if (!kstrtoul(str, 0, &enforcing))
107
		selinux_enforcing = enforcing ? 1 : 0;
L
Linus Torvalds 已提交
108 109 110 111 112 113 114 115 116 117
	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)
{
118
	unsigned long enabled;
119
	if (!kstrtoul(str, 0, &enabled))
120
		selinux_enabled = enabled ? 1 : 0;
L
Linus Torvalds 已提交
121 122 123
	return 1;
}
__setup("selinux=", selinux_enabled_setup);
124 125
#else
int selinux_enabled = 1;
L
Linus Torvalds 已提交
126 127
#endif

128
static struct kmem_cache *sel_inode_cache;
129
static struct kmem_cache *file_security_cache;
130

131 132 133 134 135 136 137
/**
 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
 *
 * Description:
 * This function checks the SECMARK reference counter to see if any SECMARK
 * targets are currently configured, if the reference counter is greater than
 * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
138 139
 * enabled, false (0) if SECMARK is disabled.  If the always_check_network
 * policy capability is enabled, SECMARK is always considered enabled.
140 141 142 143
 *
 */
static int selinux_secmark_enabled(void)
{
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159
	return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount));
}

/**
 * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled
 *
 * Description:
 * This function checks if NetLabel or labeled IPSEC is enabled.  Returns true
 * (1) if any are enabled or false (0) if neither are enabled.  If the
 * always_check_network policy capability is enabled, peer labeling
 * is always considered enabled.
 *
 */
static int selinux_peerlbl_enabled(void)
{
	return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled());
160 161
}

162 163 164 165 166 167 168 169 170 171 172
static int selinux_netcache_avc_callback(u32 event)
{
	if (event == AVC_CALLBACK_RESET) {
		sel_netif_flush();
		sel_netnode_flush();
		sel_netport_flush();
		synchronize_net();
	}
	return 0;
}

D
David Howells 已提交
173 174 175 176
/*
 * initialise the security for the init task
 */
static void cred_init_security(void)
L
Linus Torvalds 已提交
177
{
178
	struct cred *cred = (struct cred *) current->real_cred;
L
Linus Torvalds 已提交
179 180
	struct task_security_struct *tsec;

J
James Morris 已提交
181
	tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
182
	if (!tsec)
D
David Howells 已提交
183
		panic("SELinux:  Failed to initialize initial task.\n");
L
Linus Torvalds 已提交
184

D
David Howells 已提交
185
	tsec->osid = tsec->sid = SECINITSID_KERNEL;
186
	cred->security = tsec;
L
Linus Torvalds 已提交
187 188
}

189 190 191 192 193 194 195 196 197 198 199
/*
 * get the security ID of a set of credentials
 */
static inline u32 cred_sid(const struct cred *cred)
{
	const struct task_security_struct *tsec;

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

200
/*
201
 * get the objective security ID of a task
202 203 204 205 206 207
 */
static inline u32 task_sid(const struct task_struct *task)
{
	u32 sid;

	rcu_read_lock();
208
	sid = cred_sid(__task_cred(task));
209 210 211 212
	rcu_read_unlock();
	return sid;
}

213 214
/* Allocate and free functions for each kind of security blob. */

L
Linus Torvalds 已提交
215 216 217
static int inode_alloc_security(struct inode *inode)
{
	struct inode_security_struct *isec;
218
	u32 sid = current_sid();
L
Linus Torvalds 已提交
219

220
	isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
L
Linus Torvalds 已提交
221 222 223
	if (!isec)
		return -ENOMEM;

224
	spin_lock_init(&isec->lock);
L
Linus Torvalds 已提交
225 226 227 228
	INIT_LIST_HEAD(&isec->list);
	isec->inode = inode;
	isec->sid = SECINITSID_UNLABELED;
	isec->sclass = SECCLASS_FILE;
229
	isec->task_sid = sid;
A
Andreas Gruenbacher 已提交
230
	isec->initialized = LABEL_INVALID;
L
Linus Torvalds 已提交
231 232 233 234 235
	inode->i_security = isec;

	return 0;
}

236 237 238 239 240
static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);

/*
 * Try reloading inode security labels that have been marked as invalid.  The
 * @may_sleep parameter indicates when sleeping and thus reloading labels is
A
Andreas Gruenbacher 已提交
241
 * allowed; when set to false, returns -ECHILD when the label is
242 243 244 245 246 247 248 249 250 251 252
 * invalid.  The @opt_dentry parameter should be set to a dentry of the inode;
 * when no dentry is available, set it to NULL instead.
 */
static int __inode_security_revalidate(struct inode *inode,
				       struct dentry *opt_dentry,
				       bool may_sleep)
{
	struct inode_security_struct *isec = inode->i_security;

	might_sleep_if(may_sleep);

253
	if (ss_initialized && isec->initialized != LABEL_INITIALIZED) {
254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281
		if (!may_sleep)
			return -ECHILD;

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

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

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

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

282 283 284 285 286
/*
 * Get the security label of an inode.
 */
static struct inode_security_struct *inode_security(struct inode *inode)
{
287
	__inode_security_revalidate(inode, NULL, true);
288 289 290
	return inode->i_security;
}

291 292 293 294 295 296 297
static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry)
{
	struct inode *inode = d_backing_inode(dentry);

	return inode->i_security;
}

298 299 300 301 302 303 304
/*
 * Get the security label of a dentry's backing inode.
 */
static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
{
	struct inode *inode = d_backing_inode(dentry);

305
	__inode_security_revalidate(inode, dentry, true);
306 307 308
	return inode->i_security;
}

309 310 311 312 313 314 315 316
static void inode_free_rcu(struct rcu_head *head)
{
	struct inode_security_struct *isec;

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

L
Linus Torvalds 已提交
317 318 319 320 321
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;

322 323 324 325 326 327 328 329 330 331 332 333
	/*
	 * As not all inode security structures are in a list, we check for
	 * empty list outside of the lock to make sure that we won't waste
	 * time taking a lock doing nothing.
	 *
	 * The list_del_init() function can be safely called more than once.
	 * It should not be possible for this function to be called with
	 * concurrent list_add(), but for better safety against future changes
	 * in the code, we use list_empty_careful() here.
	 */
	if (!list_empty_careful(&isec->list)) {
		spin_lock(&sbsec->isec_lock);
L
Linus Torvalds 已提交
334
		list_del_init(&isec->list);
335 336
		spin_unlock(&sbsec->isec_lock);
	}
L
Linus Torvalds 已提交
337

338 339 340 341 342 343 344 345 346 347
	/*
	 * The inode may still be referenced in a path walk and
	 * a call to selinux_inode_permission() can be made
	 * after inode_free_security() is called. Ideally, the VFS
	 * wouldn't do this, but fixing that is a much harder
	 * job. For now, simply free the i_security via RCU, and
	 * leave the current inode->i_security pointer intact.
	 * The inode will be freed after the RCU grace period too.
	 */
	call_rcu(&isec->rcu, inode_free_rcu);
L
Linus Torvalds 已提交
348 349 350 351 352
}

static int file_alloc_security(struct file *file)
{
	struct file_security_struct *fsec;
353
	u32 sid = current_sid();
L
Linus Torvalds 已提交
354

355
	fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL);
L
Linus Torvalds 已提交
356 357 358
	if (!fsec)
		return -ENOMEM;

359 360
	fsec->sid = sid;
	fsec->fown_sid = sid;
L
Linus Torvalds 已提交
361 362 363 364 365 366 367 368 369
	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;
370
	kmem_cache_free(file_security_cache, fsec);
L
Linus Torvalds 已提交
371 372 373 374 375 376
}

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

J
James Morris 已提交
377
	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
378 379 380
	if (!sbsec)
		return -ENOMEM;

381
	mutex_init(&sbsec->lock);
L
Linus Torvalds 已提交
382 383 384 385 386
	INIT_LIST_HEAD(&sbsec->isec_head);
	spin_lock_init(&sbsec->isec_lock);
	sbsec->sb = sb;
	sbsec->sid = SECINITSID_UNLABELED;
	sbsec->def_sid = SECINITSID_FILE;
387
	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
L
Linus Torvalds 已提交
388 389 390 391 392 393 394 395 396 397 398 399 400 401
	sb->s_security = sbsec;

	return 0;
}

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

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

402
static const char *labeling_behaviors[7] = {
L
Linus Torvalds 已提交
403 404 405 406 407 408
	"uses xattr",
	"uses transition SIDs",
	"uses task SIDs",
	"uses genfs_contexts",
	"not configured for labeling",
	"uses mountpoint labeling",
409
	"uses native labeling",
L
Linus Torvalds 已提交
410 411 412 413 414 415 416 417
};

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

enum {
418
	Opt_error = -1,
L
Linus Torvalds 已提交
419 420
	Opt_context = 1,
	Opt_fscontext = 2,
421 422
	Opt_defcontext = 3,
	Opt_rootcontext = 4,
423
	Opt_labelsupport = 5,
424
	Opt_nextmntopt = 6,
L
Linus Torvalds 已提交
425 426
};

427 428
#define NUM_SEL_MNT_OPTS	(Opt_nextmntopt - 1)

429
static const match_table_t tokens = {
430 431 432 433
	{Opt_context, CONTEXT_STR "%s"},
	{Opt_fscontext, FSCONTEXT_STR "%s"},
	{Opt_defcontext, DEFCONTEXT_STR "%s"},
	{Opt_rootcontext, ROOTCONTEXT_STR "%s"},
434
	{Opt_labelsupport, LABELSUPP_STR},
435
	{Opt_error, NULL},
L
Linus Torvalds 已提交
436 437 438 439
};

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

440 441
static int may_context_mount_sb_relabel(u32 sid,
			struct superblock_security_struct *sbsec,
442
			const struct cred *cred)
443
{
444
	const struct task_security_struct *tsec = cred->security;
445 446 447 448 449 450 451 452 453 454 455 456
	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;
}

457 458
static int may_context_mount_inode_relabel(u32 sid,
			struct superblock_security_struct *sbsec,
459
			const struct cred *cred)
460
{
461
	const struct task_security_struct *tsec = cred->security;
462 463 464 465 466 467 468 469 470 471 472
	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;
}

473 474 475 476
static int selinux_is_sblabel_mnt(struct super_block *sb)
{
	struct superblock_security_struct *sbsec = sb->s_security;

477 478 479
	return sbsec->behavior == SECURITY_FS_USE_XATTR ||
		sbsec->behavior == SECURITY_FS_USE_TRANS ||
		sbsec->behavior == SECURITY_FS_USE_TASK ||
480
		sbsec->behavior == SECURITY_FS_USE_NATIVE ||
481 482
		/* Special handling. Genfs but also in-core setxattr handler */
		!strcmp(sb->s_type->name, "sysfs") ||
483 484
		!strcmp(sb->s_type->name, "cgroup") ||
		!strcmp(sb->s_type->name, "cgroup2") ||
485 486
		!strcmp(sb->s_type->name, "pstore") ||
		!strcmp(sb->s_type->name, "debugfs") ||
487
		!strcmp(sb->s_type->name, "tracefs") ||
488
		!strcmp(sb->s_type->name, "rootfs");
489 490
}

491
static int sb_finish_set_opts(struct super_block *sb)
L
Linus Torvalds 已提交
492 493
{
	struct superblock_security_struct *sbsec = sb->s_security;
494
	struct dentry *root = sb->s_root;
495
	struct inode *root_inode = d_backing_inode(root);
496
	int rc = 0;
L
Linus Torvalds 已提交
497

498 499 500 501 502 503
	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. */
504
		if (!(root_inode->i_opflags & IOP_XATTR)) {
505 506
			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
			       "xattr support\n", sb->s_id, sb->s_type->name);
507 508 509
			rc = -EOPNOTSUPP;
			goto out;
		}
510 511

		rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0);
512 513 514
		if (rc < 0 && rc != -ENODATA) {
			if (rc == -EOPNOTSUPP)
				printk(KERN_WARNING "SELinux: (dev %s, type "
515 516
				       "%s) has no security xattr handler\n",
				       sb->s_id, sb->s_type->name);
517 518
			else
				printk(KERN_WARNING "SELinux: (dev %s, type "
519 520
				       "%s) getxattr errno %d\n", sb->s_id,
				       sb->s_type->name, -rc);
521 522 523
			goto out;
		}
	}
L
Linus Torvalds 已提交
524

525
	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
526 527
		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
		       sb->s_id, sb->s_type->name);
L
Linus Torvalds 已提交
528

529
	sbsec->flags |= SE_SBINITIALIZED;
530
	if (selinux_is_sblabel_mnt(sb))
531
		sbsec->flags |= SBLABEL_MNT;
532

533 534
	/* Initialize the root inode. */
	rc = inode_doinit_with_dentry(root_inode, root);
L
Linus Torvalds 已提交
535

536 537 538 539 540 541 542 543 544 545 546
	/* 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;
547
		list_del_init(&isec->list);
548 549 550 551 552 553 554 555 556 557 558 559 560 561
		spin_unlock(&sbsec->isec_lock);
		inode = igrab(inode);
		if (inode) {
			if (!IS_PRIVATE(inode))
				inode_doinit(inode);
			iput(inode);
		}
		spin_lock(&sbsec->isec_lock);
		goto next_inode;
	}
	spin_unlock(&sbsec->isec_lock);
out:
	return rc;
}
L
Linus Torvalds 已提交
562

563 564 565 566 567 568
/*
 * This function should allow an FS to ask what it's mount security
 * options were so it can use those later for submounts, displaying
 * mount options, or whatever.
 */
static int selinux_get_mnt_opts(const struct super_block *sb,
569
				struct security_mnt_opts *opts)
570 571 572 573 574 575
{
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
	char *context = NULL;
	u32 len;
	char tmp;
L
Linus Torvalds 已提交
576

577
	security_init_mnt_opts(opts);
L
Linus Torvalds 已提交
578

579
	if (!(sbsec->flags & SE_SBINITIALIZED))
580
		return -EINVAL;
L
Linus Torvalds 已提交
581

582 583
	if (!ss_initialized)
		return -EINVAL;
L
Linus Torvalds 已提交
584

585 586 587
	/* make sure we always check enough bits to cover the mask */
	BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));

588
	tmp = sbsec->flags & SE_MNTMASK;
589
	/* count the number of mount options for this sb */
590
	for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
591
		if (tmp & 0x01)
592
			opts->num_mnt_opts++;
593 594
		tmp >>= 1;
	}
595
	/* Check if the Label support flag is set */
596
	if (sbsec->flags & SBLABEL_MNT)
597
		opts->num_mnt_opts++;
L
Linus Torvalds 已提交
598

599 600
	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts) {
601 602 603
		rc = -ENOMEM;
		goto out_free;
	}
L
Linus Torvalds 已提交
604

605 606
	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
607 608 609
		rc = -ENOMEM;
		goto out_free;
	}
L
Linus Torvalds 已提交
610

611 612 613 614 615
	i = 0;
	if (sbsec->flags & FSCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->sid, &context, &len);
		if (rc)
			goto out_free;
616 617
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
618 619 620 621 622
	}
	if (sbsec->flags & CONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
		if (rc)
			goto out_free;
623 624
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
625 626 627 628 629
	}
	if (sbsec->flags & DEFCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
		if (rc)
			goto out_free;
630 631
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
632 633
	}
	if (sbsec->flags & ROOTCONTEXT_MNT) {
634 635
		struct dentry *root = sbsec->sb->s_root;
		struct inode_security_struct *isec = backing_inode_security(root);
636

637 638 639
		rc = security_sid_to_context(isec->sid, &context, &len);
		if (rc)
			goto out_free;
640 641
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
642
	}
643
	if (sbsec->flags & SBLABEL_MNT) {
644
		opts->mnt_opts[i] = NULL;
645
		opts->mnt_opts_flags[i++] = SBLABEL_MNT;
646
	}
L
Linus Torvalds 已提交
647

648
	BUG_ON(i != opts->num_mnt_opts);
L
Linus Torvalds 已提交
649

650 651 652
	return 0;

out_free:
653
	security_free_mnt_opts(opts);
654 655
	return rc;
}
L
Linus Torvalds 已提交
656

657 658 659
static int bad_option(struct superblock_security_struct *sbsec, char flag,
		      u32 old_sid, u32 new_sid)
{
660 661
	char mnt_flags = sbsec->flags & SE_MNTMASK;

662
	/* check if the old mount command had the same options */
663
	if (sbsec->flags & SE_SBINITIALIZED)
664 665 666 667 668 669 670
		if (!(sbsec->flags & flag) ||
		    (old_sid != new_sid))
			return 1;

	/* check if we were passed the same options twice,
	 * aka someone passed context=a,context=b
	 */
671 672
	if (!(sbsec->flags & SE_SBINITIALIZED))
		if (mnt_flags & flag)
673 674 675
			return 1;
	return 0;
}
676

677 678 679 680
/*
 * Allow filesystems with binary mount data to explicitly set mount point
 * labeling information.
 */
681
static int selinux_set_mnt_opts(struct super_block *sb,
682 683 684
				struct security_mnt_opts *opts,
				unsigned long kern_flags,
				unsigned long *set_kern_flags)
685
{
686
	const struct cred *cred = current_cred();
687 688
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
689
	const char *name = sb->s_type->name;
690
	struct dentry *root = sbsec->sb->s_root;
691
	struct inode_security_struct *root_isec;
692 693
	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
	u32 defcontext_sid = 0;
694 695 696
	char **mount_options = opts->mnt_opts;
	int *flags = opts->mnt_opts_flags;
	int num_opts = opts->num_mnt_opts;
697 698 699 700 701 702 703 704 705 706 707

	mutex_lock(&sbsec->lock);

	if (!ss_initialized) {
		if (!num_opts) {
			/* Defer initialization until selinux_complete_init,
			   after the initial policy is loaded and the security
			   server is ready to handle calls. */
			goto out;
		}
		rc = -EINVAL;
E
Eric Paris 已提交
708 709
		printk(KERN_WARNING "SELinux: Unable to set superblock options "
			"before the security server is initialized\n");
L
Linus Torvalds 已提交
710
		goto out;
711
	}
712 713 714 715 716 717
	if (kern_flags && !set_kern_flags) {
		/* Specifying internal flags without providing a place to
		 * place the results is not allowed */
		rc = -EINVAL;
		goto out;
	}
L
Linus Torvalds 已提交
718

719 720 721 722 723 724 725 726 727 728 729
	/*
	 * Binary mount data FS will come through this function twice.  Once
	 * from an explicit call and once from the generic calls from the vfs.
	 * Since the generic VFS calls will not contain any security mount data
	 * we need to skip the double mount verification.
	 *
	 * This does open a hole in which we will not notice if the first
	 * mount using this sb set explict options and a second mount using
	 * this sb does not set any security options.  (The first options
	 * will be used for both mounts)
	 */
730
	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
731
	    && (num_opts == 0))
732
		goto out;
733

734 735
	root_isec = backing_inode_security_novalidate(root);

736 737 738 739 740 741 742
	/*
	 * parse the mount options, check if they are valid sids.
	 * also check if someone is trying to mount the same sb more
	 * than once with different security options.
	 */
	for (i = 0; i < num_opts; i++) {
		u32 sid;
743

744
		if (flags[i] == SBLABEL_MNT)
745
			continue;
746
		rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL);
L
Linus Torvalds 已提交
747
		if (rc) {
748
			printk(KERN_WARNING "SELinux: security_context_str_to_sid"
749 750
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, name, rc);
751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794
			goto out;
		}
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			fscontext_sid = sid;

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

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

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

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

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

			sbsec->flags |= ROOTCONTEXT_MNT;

			break;
		case DEFCONTEXT_MNT:
			defcontext_sid = sid;

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

			sbsec->flags |= DEFCONTEXT_MNT;

			break;
		default:
			rc = -EINVAL;
			goto out;
L
Linus Torvalds 已提交
795
		}
796 797
	}

798
	if (sbsec->flags & SE_SBINITIALIZED) {
799
		/* previously mounted with options, but not on this attempt? */
800
		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
801 802 803 804 805
			goto out_double_mount;
		rc = 0;
		goto out;
	}

806
	if (strcmp(sb->s_type->name, "proc") == 0)
807 808
		sbsec->flags |= SE_SBPROC | SE_SBGENFS;

809 810 811
	if (!strcmp(sb->s_type->name, "debugfs") ||
	    !strcmp(sb->s_type->name, "sysfs") ||
	    !strcmp(sb->s_type->name, "pstore"))
812
		sbsec->flags |= SE_SBGENFS;
813

814 815 816 817 818
	if (!sbsec->behavior) {
		/*
		 * Determine the labeling behavior to use for this
		 * filesystem type.
		 */
819
		rc = security_fs_use(sb);
820 821 822 823 824 825
		if (rc) {
			printk(KERN_WARNING
				"%s: security_fs_use(%s) returned %d\n",
					__func__, sb->s_type->name, rc);
			goto out;
		}
826
	}
827 828

	/*
829 830 831
	 * If this is a user namespace mount and the filesystem type is not
	 * explicitly whitelisted, then no contexts are allowed on the command
	 * line and security labels must be ignored.
832
	 */
833 834 835 836
	if (sb->s_user_ns != &init_user_ns &&
	    strcmp(sb->s_type->name, "tmpfs") &&
	    strcmp(sb->s_type->name, "ramfs") &&
	    strcmp(sb->s_type->name, "devpts")) {
837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852
		if (context_sid || fscontext_sid || rootcontext_sid ||
		    defcontext_sid) {
			rc = -EACCES;
			goto out;
		}
		if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
			sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
			rc = security_transition_sid(current_sid(), current_sid(),
						     SECCLASS_FILE, NULL,
						     &sbsec->mntpoint_sid);
			if (rc)
				goto out;
		}
		goto out_set_opts;
	}

853 854
	/* sets the context of the superblock for the fs being mounted. */
	if (fscontext_sid) {
855
		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
L
Linus Torvalds 已提交
856
		if (rc)
857
			goto out;
L
Linus Torvalds 已提交
858

859
		sbsec->sid = fscontext_sid;
860 861 862 863 864 865 866
	}

	/*
	 * 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.
	 */
867 868 869 870 871
	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
		sbsec->behavior = SECURITY_FS_USE_NATIVE;
		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
	}

872 873
	if (context_sid) {
		if (!fscontext_sid) {
874 875
			rc = may_context_mount_sb_relabel(context_sid, sbsec,
							  cred);
876
			if (rc)
877 878
				goto out;
			sbsec->sid = context_sid;
879
		} else {
880 881
			rc = may_context_mount_inode_relabel(context_sid, sbsec,
							     cred);
882
			if (rc)
883
				goto out;
884
		}
885 886
		if (!rootcontext_sid)
			rootcontext_sid = context_sid;
L
Linus Torvalds 已提交
887

888
		sbsec->mntpoint_sid = context_sid;
889
		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
L
Linus Torvalds 已提交
890 891
	}

892
	if (rootcontext_sid) {
893 894
		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
						     cred);
895
		if (rc)
896
			goto out;
897

898
		root_isec->sid = rootcontext_sid;
899
		root_isec->initialized = LABEL_INITIALIZED;
900 901
	}

902
	if (defcontext_sid) {
903 904
		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
905 906 907 908
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux: defcontext option is "
			       "invalid for this filesystem type\n");
			goto out;
L
Linus Torvalds 已提交
909 910
		}

911 912
		if (defcontext_sid != sbsec->def_sid) {
			rc = may_context_mount_inode_relabel(defcontext_sid,
913
							     sbsec, cred);
914 915 916
			if (rc)
				goto out;
		}
L
Linus Torvalds 已提交
917

918
		sbsec->def_sid = defcontext_sid;
L
Linus Torvalds 已提交
919 920
	}

921
out_set_opts:
922
	rc = sb_finish_set_opts(sb);
L
Linus Torvalds 已提交
923
out:
924
	mutex_unlock(&sbsec->lock);
L
Linus Torvalds 已提交
925
	return rc;
926 927 928
out_double_mount:
	rc = -EINVAL;
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
929
	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
930
	goto out;
L
Linus Torvalds 已提交
931 932
}

933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949
static int selinux_cmp_sb_context(const struct super_block *oldsb,
				    const struct super_block *newsb)
{
	struct superblock_security_struct *old = oldsb->s_security;
	struct superblock_security_struct *new = newsb->s_security;
	char oldflags = old->flags & SE_MNTMASK;
	char newflags = new->flags & SE_MNTMASK;

	if (oldflags != newflags)
		goto mismatch;
	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
		goto mismatch;
	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
		goto mismatch;
	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
		goto mismatch;
	if (oldflags & ROOTCONTEXT_MNT) {
950 951
		struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
		struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
952 953 954 955 956 957 958 959 960 961 962 963
		if (oldroot->sid != newroot->sid)
			goto mismatch;
	}
	return 0;
mismatch:
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, "
			    "different security settings for (dev %s, "
			    "type %s)\n", newsb->s_id, newsb->s_type->name);
	return -EBUSY;
}

static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
964
					struct super_block *newsb)
L
Linus Torvalds 已提交
965
{
966 967
	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
	struct superblock_security_struct *newsbsec = newsb->s_security;
L
Linus Torvalds 已提交
968

969 970 971
	int set_fscontext =	(oldsbsec->flags & FSCONTEXT_MNT);
	int set_context =	(oldsbsec->flags & CONTEXT_MNT);
	int set_rootcontext =	(oldsbsec->flags & ROOTCONTEXT_MNT);
L
Linus Torvalds 已提交
972

973 974
	/*
	 * if the parent was able to be mounted it clearly had no special lsm
975
	 * mount options.  thus we can safely deal with this superblock later
976
	 */
977
	if (!ss_initialized)
978
		return 0;
979 980

	/* how can we clone if the old one wasn't set up?? */
981
	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
982

983
	/* if fs is reusing a sb, make sure that the contexts match */
984
	if (newsbsec->flags & SE_SBINITIALIZED)
985
		return selinux_cmp_sb_context(oldsb, newsb);
986

987 988 989 990 991 992 993 994 995 996 997 998 999 1000
	mutex_lock(&newsbsec->lock);

	newsbsec->flags = oldsbsec->flags;

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

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

		if (!set_fscontext)
			newsbsec->sid = sid;
		if (!set_rootcontext) {
1001
			struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
1002 1003 1004
			newisec->sid = sid;
		}
		newsbsec->mntpoint_sid = sid;
L
Linus Torvalds 已提交
1005
	}
1006
	if (set_rootcontext) {
1007 1008
		const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
		struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
L
Linus Torvalds 已提交
1009

1010
		newisec->sid = oldisec->sid;
L
Linus Torvalds 已提交
1011 1012
	}

1013 1014
	sb_finish_set_opts(newsb);
	mutex_unlock(&newsbsec->lock);
1015
	return 0;
1016 1017
}

1018 1019
static int selinux_parse_opts_str(char *options,
				  struct security_mnt_opts *opts)
1020
{
1021
	char *p;
1022 1023
	char *context = NULL, *defcontext = NULL;
	char *fscontext = NULL, *rootcontext = NULL;
1024
	int rc, num_mnt_opts = 0;
L
Linus Torvalds 已提交
1025

1026
	opts->num_mnt_opts = 0;
L
Linus Torvalds 已提交
1027

1028 1029 1030 1031
	/* Standard string-based options. */
	while ((p = strsep(&options, "|")) != NULL) {
		int token;
		substring_t args[MAX_OPT_ARGS];
L
Linus Torvalds 已提交
1032

1033 1034
		if (!*p)
			continue;
L
Linus Torvalds 已提交
1035

1036
		token = match_token(p, tokens, args);
L
Linus Torvalds 已提交
1037

1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089
		switch (token) {
		case Opt_context:
			if (context || defcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			context = match_strdup(&args[0]);
			if (!context) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;

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

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

		case Opt_defcontext:
			if (context || defcontext) {
				rc = -EINVAL;
				printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
				goto out_err;
			}
			defcontext = match_strdup(&args[0]);
			if (!defcontext) {
				rc = -ENOMEM;
				goto out_err;
			}
			break;
1090 1091
		case Opt_labelsupport:
			break;
1092 1093 1094 1095
		default:
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux:  unknown mount option\n");
			goto out_err;
L
Linus Torvalds 已提交
1096 1097 1098

		}
	}
1099

1100
	rc = -ENOMEM;
1101
	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_KERNEL);
1102 1103 1104
	if (!opts->mnt_opts)
		goto out_err;

1105 1106
	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int),
				       GFP_KERNEL);
1107 1108 1109 1110 1111
	if (!opts->mnt_opts_flags) {
		kfree(opts->mnt_opts);
		goto out_err;
	}

1112
	if (fscontext) {
1113 1114
		opts->mnt_opts[num_mnt_opts] = fscontext;
		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
1115 1116
	}
	if (context) {
1117 1118
		opts->mnt_opts[num_mnt_opts] = context;
		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
1119 1120
	}
	if (rootcontext) {
1121 1122
		opts->mnt_opts[num_mnt_opts] = rootcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
1123 1124
	}
	if (defcontext) {
1125 1126
		opts->mnt_opts[num_mnt_opts] = defcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
1127 1128
	}

1129 1130 1131
	opts->num_mnt_opts = num_mnt_opts;
	return 0;

1132 1133 1134 1135 1136
out_err:
	kfree(context);
	kfree(defcontext);
	kfree(fscontext);
	kfree(rootcontext);
L
Linus Torvalds 已提交
1137 1138
	return rc;
}
1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159
/*
 * string mount options parsing and call set the sbsec
 */
static int superblock_doinit(struct super_block *sb, void *data)
{
	int rc = 0;
	char *options = data;
	struct security_mnt_opts opts;

	security_init_mnt_opts(&opts);

	if (!data)
		goto out;

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

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

out:
1160
	rc = selinux_set_mnt_opts(sb, &opts, 0, NULL);
1161 1162 1163 1164 1165

out_err:
	security_free_mnt_opts(&opts);
	return rc;
}
L
Linus Torvalds 已提交
1166

A
Adrian Bunk 已提交
1167 1168
static void selinux_write_opts(struct seq_file *m,
			       struct security_mnt_opts *opts)
1169 1170 1171 1172 1173
{
	int i;
	char *prefix;

	for (i = 0; i < opts->num_mnt_opts; i++) {
1174 1175 1176 1177 1178 1179
		char *has_comma;

		if (opts->mnt_opts[i])
			has_comma = strchr(opts->mnt_opts[i], ',');
		else
			has_comma = NULL;
1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193

		switch (opts->mnt_opts_flags[i]) {
		case CONTEXT_MNT:
			prefix = CONTEXT_STR;
			break;
		case FSCONTEXT_MNT:
			prefix = FSCONTEXT_STR;
			break;
		case ROOTCONTEXT_MNT:
			prefix = ROOTCONTEXT_STR;
			break;
		case DEFCONTEXT_MNT:
			prefix = DEFCONTEXT_STR;
			break;
1194
		case SBLABEL_MNT:
1195 1196 1197
			seq_putc(m, ',');
			seq_puts(m, LABELSUPP_STR);
			continue;
1198 1199
		default:
			BUG();
1200
			return;
1201 1202 1203 1204 1205 1206
		};
		/* we need a comma before each option */
		seq_putc(m, ',');
		seq_puts(m, prefix);
		if (has_comma)
			seq_putc(m, '\"');
1207
		seq_escape(m, opts->mnt_opts[i], "\"\n\\");
1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218
		if (has_comma)
			seq_putc(m, '\"');
	}
}

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

	rc = selinux_get_mnt_opts(sb, &opts);
1219 1220 1221 1222
	if (rc) {
		/* before policy load we may get EINVAL, don't show anything */
		if (rc == -EINVAL)
			rc = 0;
1223
		return rc;
1224
	}
1225 1226 1227 1228 1229 1230 1231 1232

	selinux_write_opts(m, &opts);

	security_free_mnt_opts(&opts);

	return rc;
}

L
Linus Torvalds 已提交
1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255
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;
}

1256 1257 1258 1259 1260 1261 1262 1263 1264 1265
static inline int default_protocol_stream(int protocol)
{
	return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
}

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

L
Linus Torvalds 已提交
1266 1267
static inline u16 socket_type_to_security_class(int family, int type, int protocol)
{
1268 1269
	int extsockclass = selinux_policycap_extsockclass;

L
Linus Torvalds 已提交
1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283
	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:
1284
		case SOCK_SEQPACKET:
1285 1286
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
1287 1288
			else if (extsockclass && protocol == IPPROTO_SCTP)
				return SECCLASS_SCTP_SOCKET;
1289 1290
			else
				return SECCLASS_RAWIP_SOCKET;
L
Linus Torvalds 已提交
1291
		case SOCK_DGRAM:
1292 1293
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
1294 1295
			else if (extsockclass && (protocol == IPPROTO_ICMP ||
						  protocol == IPPROTO_ICMPV6))
1296
				return SECCLASS_ICMP_SOCKET;
1297 1298
			else
				return SECCLASS_RAWIP_SOCKET;
J
James Morris 已提交
1299 1300
		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
1301
		default:
L
Linus Torvalds 已提交
1302 1303 1304 1305 1306 1307 1308
			return SECCLASS_RAWIP_SOCKET;
		}
		break;
	case PF_NETLINK:
		switch (protocol) {
		case NETLINK_ROUTE:
			return SECCLASS_NETLINK_ROUTE_SOCKET;
1309
		case NETLINK_SOCK_DIAG:
L
Linus Torvalds 已提交
1310 1311 1312 1313 1314 1315 1316
			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;
1317 1318
		case NETLINK_ISCSI:
			return SECCLASS_NETLINK_ISCSI_SOCKET;
L
Linus Torvalds 已提交
1319 1320
		case NETLINK_AUDIT:
			return SECCLASS_NETLINK_AUDIT_SOCKET;
1321 1322 1323 1324 1325 1326
		case NETLINK_FIB_LOOKUP:
			return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET;
		case NETLINK_CONNECTOR:
			return SECCLASS_NETLINK_CONNECTOR_SOCKET;
		case NETLINK_NETFILTER:
			return SECCLASS_NETLINK_NETFILTER_SOCKET;
L
Linus Torvalds 已提交
1327 1328
		case NETLINK_DNRTMSG:
			return SECCLASS_NETLINK_DNRT_SOCKET;
1329 1330
		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1331 1332 1333 1334 1335 1336 1337 1338
		case NETLINK_GENERIC:
			return SECCLASS_NETLINK_GENERIC_SOCKET;
		case NETLINK_SCSITRANSPORT:
			return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET;
		case NETLINK_RDMA:
			return SECCLASS_NETLINK_RDMA_SOCKET;
		case NETLINK_CRYPTO:
			return SECCLASS_NETLINK_CRYPTO_SOCKET;
L
Linus Torvalds 已提交
1339 1340 1341 1342 1343 1344 1345
		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
1346 1347
	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
L
Linus Torvalds 已提交
1348 1349
	}

1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403
	if (extsockclass) {
		switch (family) {
		case PF_AX25:
			return SECCLASS_AX25_SOCKET;
		case PF_IPX:
			return SECCLASS_IPX_SOCKET;
		case PF_NETROM:
			return SECCLASS_NETROM_SOCKET;
		case PF_ATMPVC:
			return SECCLASS_ATMPVC_SOCKET;
		case PF_X25:
			return SECCLASS_X25_SOCKET;
		case PF_ROSE:
			return SECCLASS_ROSE_SOCKET;
		case PF_DECnet:
			return SECCLASS_DECNET_SOCKET;
		case PF_ATMSVC:
			return SECCLASS_ATMSVC_SOCKET;
		case PF_RDS:
			return SECCLASS_RDS_SOCKET;
		case PF_IRDA:
			return SECCLASS_IRDA_SOCKET;
		case PF_PPPOX:
			return SECCLASS_PPPOX_SOCKET;
		case PF_LLC:
			return SECCLASS_LLC_SOCKET;
		case PF_CAN:
			return SECCLASS_CAN_SOCKET;
		case PF_TIPC:
			return SECCLASS_TIPC_SOCKET;
		case PF_BLUETOOTH:
			return SECCLASS_BLUETOOTH_SOCKET;
		case PF_IUCV:
			return SECCLASS_IUCV_SOCKET;
		case PF_RXRPC:
			return SECCLASS_RXRPC_SOCKET;
		case PF_ISDN:
			return SECCLASS_ISDN_SOCKET;
		case PF_PHONET:
			return SECCLASS_PHONET_SOCKET;
		case PF_IEEE802154:
			return SECCLASS_IEEE802154_SOCKET;
		case PF_CAIF:
			return SECCLASS_CAIF_SOCKET;
		case PF_ALG:
			return SECCLASS_ALG_SOCKET;
		case PF_NFC:
			return SECCLASS_NFC_SOCKET;
		case PF_VSOCK:
			return SECCLASS_VSOCK_SOCKET;
		case PF_KCM:
			return SECCLASS_KCM_SOCKET;
		case PF_QIPCRTR:
			return SECCLASS_QIPCRTR_SOCKET;
1404 1405 1406
		case PF_SMC:
			return SECCLASS_SMC_SOCKET;
#if PF_MAX > 44
1407 1408 1409 1410 1411
#error New address family defined, please update this function.
#endif
		}
	}

L
Linus Torvalds 已提交
1412 1413 1414
	return SECCLASS_SOCKET;
}

1415 1416 1417 1418
static int selinux_genfs_get_sid(struct dentry *dentry,
				 u16 tclass,
				 u16 flags,
				 u32 *sid)
L
Linus Torvalds 已提交
1419
{
1420
	int rc;
1421
	struct super_block *sb = dentry->d_sb;
1422
	char *buffer, *path;
L
Linus Torvalds 已提交
1423

1424
	buffer = (char *)__get_free_page(GFP_KERNEL);
L
Linus Torvalds 已提交
1425 1426 1427
	if (!buffer)
		return -ENOMEM;

1428 1429 1430 1431
	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
	if (IS_ERR(path))
		rc = PTR_ERR(path);
	else {
1432 1433 1434 1435 1436 1437 1438 1439
		if (flags & SE_SBPROC) {
			/* each process gets a /proc/PID/ entry. Strip off the
			 * PID part to get a valid selinux labeling.
			 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
			while (path[1] >= '0' && path[1] <= '9') {
				path[1] = '/';
				path++;
			}
1440
		}
1441
		rc = security_genfs_sid(sb->s_type->name, path, tclass, sid);
L
Linus Torvalds 已提交
1442 1443 1444 1445 1446 1447 1448 1449 1450 1451
	}
	free_page((unsigned long)buffer);
	return rc;
}

/* The inode's security attributes must be initialized before first use. */
static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
{
	struct superblock_security_struct *sbsec = NULL;
	struct inode_security_struct *isec = inode->i_security;
1452 1453
	u32 task_sid, sid = 0;
	u16 sclass;
L
Linus Torvalds 已提交
1454 1455 1456 1457 1458 1459
	struct dentry *dentry;
#define INITCONTEXTLEN 255
	char *context = NULL;
	unsigned len = 0;
	int rc = 0;

1460
	if (isec->initialized == LABEL_INITIALIZED)
1461
		return 0;
L
Linus Torvalds 已提交
1462

1463
	spin_lock(&isec->lock);
1464
	if (isec->initialized == LABEL_INITIALIZED)
1465
		goto out_unlock;
L
Linus Torvalds 已提交
1466

1467 1468 1469
	if (isec->sclass == SECCLASS_FILE)
		isec->sclass = inode_mode_to_security_class(inode->i_mode);

L
Linus Torvalds 已提交
1470
	sbsec = inode->i_sb->s_security;
1471
	if (!(sbsec->flags & SE_SBINITIALIZED)) {
L
Linus Torvalds 已提交
1472 1473 1474 1475 1476 1477 1478
		/* 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);
1479
		goto out_unlock;
L
Linus Torvalds 已提交
1480 1481
	}

1482 1483 1484 1485 1486 1487
	sclass = isec->sclass;
	task_sid = isec->task_sid;
	sid = isec->sid;
	isec->initialized = LABEL_PENDING;
	spin_unlock(&isec->lock);

L
Linus Torvalds 已提交
1488
	switch (sbsec->behavior) {
1489 1490
	case SECURITY_FS_USE_NATIVE:
		break;
L
Linus Torvalds 已提交
1491
	case SECURITY_FS_USE_XATTR:
1492
		if (!(inode->i_opflags & IOP_XATTR)) {
1493
			sid = sbsec->def_sid;
L
Linus Torvalds 已提交
1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505
			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) {
1506 1507 1508 1509 1510 1511 1512 1513 1514
			/*
			 * this is can be hit on boot when a file is accessed
			 * before the policy is loaded.  When we load policy we
			 * may find inodes that have no dentry on the
			 * sbsec->isec_head list.  No reason to complain as these
			 * will get fixed up the next time we go through
			 * inode_doinit with a dentry, before these inodes could
			 * be used again by userspace.
			 */
1515
			goto out;
L
Linus Torvalds 已提交
1516 1517 1518
		}

		len = INITCONTEXTLEN;
1519
		context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1520 1521 1522
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
1523
			goto out;
L
Linus Torvalds 已提交
1524
		}
1525
		context[len] = '\0';
1526
		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
L
Linus Torvalds 已提交
1527
		if (rc == -ERANGE) {
1528 1529
			kfree(context);

L
Linus Torvalds 已提交
1530
			/* Need a larger buffer.  Query for the right size. */
1531
			rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
L
Linus Torvalds 已提交
1532 1533
			if (rc < 0) {
				dput(dentry);
1534
				goto out;
L
Linus Torvalds 已提交
1535 1536
			}
			len = rc;
1537
			context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1538 1539 1540
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
1541
				goto out;
L
Linus Torvalds 已提交
1542
			}
1543
			context[len] = '\0';
1544
			rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
L
Linus Torvalds 已提交
1545 1546 1547 1548
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
E
Eric Paris 已提交
1549
				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1550
				       "%d for dev=%s ino=%ld\n", __func__,
L
Linus Torvalds 已提交
1551 1552
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
1553
				goto out;
L
Linus Torvalds 已提交
1554 1555 1556 1557 1558
			}
			/* Map ENODATA to the default file SID */
			sid = sbsec->def_sid;
			rc = 0;
		} else {
1559
			rc = security_context_to_sid_default(context, rc, &sid,
1560 1561
							     sbsec->def_sid,
							     GFP_NOFS);
L
Linus Torvalds 已提交
1562
			if (rc) {
1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
				char *dev = inode->i_sb->s_id;
				unsigned long ino = inode->i_ino;

				if (rc == -EINVAL) {
					if (printk_ratelimit())
						printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
							"context=%s.  This indicates you may need to relabel the inode or the "
							"filesystem in question.\n", ino, dev, context);
				} else {
					printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
					       "returned %d for dev=%s ino=%ld\n",
					       __func__, context, -rc, dev, ino);
				}
L
Linus Torvalds 已提交
1576 1577 1578 1579 1580 1581 1582 1583 1584
				kfree(context);
				/* Leave with the unlabeled SID */
				rc = 0;
				break;
			}
		}
		kfree(context);
		break;
	case SECURITY_FS_USE_TASK:
1585
		sid = task_sid;
L
Linus Torvalds 已提交
1586 1587 1588
		break;
	case SECURITY_FS_USE_TRANS:
		/* Default to the fs SID. */
1589
		sid = sbsec->sid;
L
Linus Torvalds 已提交
1590 1591

		/* Try to obtain a transition SID. */
1592
		rc = security_transition_sid(task_sid, sid, sclass, NULL, &sid);
L
Linus Torvalds 已提交
1593
		if (rc)
1594
			goto out;
L
Linus Torvalds 已提交
1595
		break;
1596
	case SECURITY_FS_USE_MNTPOINT:
1597
		sid = sbsec->mntpoint_sid;
1598
		break;
L
Linus Torvalds 已提交
1599
	default:
1600
		/* Default to the fs superblock SID. */
1601
		sid = sbsec->sid;
L
Linus Torvalds 已提交
1602

1603
		if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) {
1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623
			/* We must have a dentry to determine the label on
			 * procfs inodes */
			if (opt_dentry)
				/* Called from d_instantiate or
				 * d_splice_alias. */
				dentry = dget(opt_dentry);
			else
				/* Called from selinux_complete_init, try to
				 * find a dentry. */
				dentry = d_find_alias(inode);
			/*
			 * This can be hit on boot when a file is accessed
			 * before the policy is loaded.  When we load policy we
			 * may find inodes that have no dentry on the
			 * sbsec->isec_head list.  No reason to complain as
			 * these will get fixed up the next time we go through
			 * inode_doinit() with a dentry, before these inodes
			 * could be used again by userspace.
			 */
			if (!dentry)
1624 1625
				goto out;
			rc = selinux_genfs_get_sid(dentry, sclass,
1626
						   sbsec->flags, &sid);
1627 1628
			dput(dentry);
			if (rc)
1629
				goto out;
L
Linus Torvalds 已提交
1630 1631 1632 1633
		}
		break;
	}

1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644
out:
	spin_lock(&isec->lock);
	if (isec->initialized == LABEL_PENDING) {
		if (!sid || rc) {
			isec->initialized = LABEL_INVALID;
			goto out_unlock;
		}

		isec->initialized = LABEL_INITIALIZED;
		isec->sid = sid;
	}
L
Linus Torvalds 已提交
1645

1646
out_unlock:
1647
	spin_unlock(&isec->lock);
L
Linus Torvalds 已提交
1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677
	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;
}

1678 1679 1680 1681
#if CAP_LAST_CAP > 63
#error Fix SELinux to handle capabilities > 63.
#endif

L
Linus Torvalds 已提交
1682
/* Check whether a task is allowed to use a capability. */
1683
static int cred_has_capability(const struct cred *cred,
1684
			       int cap, int audit, bool initns)
L
Linus Torvalds 已提交
1685
{
1686
	struct common_audit_data ad;
1687
	struct av_decision avd;
1688
	u16 sclass;
1689
	u32 sid = cred_sid(cred);
1690
	u32 av = CAP_TO_MASK(cap);
1691
	int rc;
L
Linus Torvalds 已提交
1692

1693
	ad.type = LSM_AUDIT_DATA_CAP;
L
Linus Torvalds 已提交
1694 1695
	ad.u.cap = cap;

1696 1697
	switch (CAP_TO_INDEX(cap)) {
	case 0:
1698
		sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS;
1699 1700
		break;
	case 1:
1701
		sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS;
1702 1703 1704 1705 1706
		break;
	default:
		printk(KERN_ERR
		       "SELinux:  out of range capability %d\n", cap);
		BUG();
1707
		return -EINVAL;
1708
	}
1709

1710
	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1711
	if (audit == SECURITY_CAP_AUDIT) {
1712
		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1713 1714 1715
		if (rc2)
			return rc2;
	}
1716
	return rc;
L
Linus Torvalds 已提交
1717 1718 1719 1720 1721
}

/* 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). */
1722
static int inode_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1723 1724
			  struct inode *inode,
			  u32 perms,
1725
			  struct common_audit_data *adp)
L
Linus Torvalds 已提交
1726 1727
{
	struct inode_security_struct *isec;
1728
	u32 sid;
L
Linus Torvalds 已提交
1729

1730 1731
	validate_creds(cred);

1732
	if (unlikely(IS_PRIVATE(inode)))
1733 1734
		return 0;

1735
	sid = cred_sid(cred);
L
Linus Torvalds 已提交
1736 1737
	isec = inode->i_security;

1738
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
L
Linus Torvalds 已提交
1739 1740 1741 1742 1743
}

/* 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. */
1744
static inline int dentry_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1745 1746 1747
				  struct dentry *dentry,
				  u32 av)
{
1748
	struct inode *inode = d_backing_inode(dentry);
1749
	struct common_audit_data ad;
1750

1751
	ad.type = LSM_AUDIT_DATA_DENTRY;
E
Eric Paris 已提交
1752
	ad.u.dentry = dentry;
1753
	__inode_security_revalidate(inode, dentry, true);
1754
	return inode_has_perm(cred, inode, av, &ad);
E
Eric Paris 已提交
1755 1756 1757 1758 1759 1760
}

/* Same as inode_has_perm, but pass explicit audit data containing
   the path to help the auditing code to more easily generate the
   pathname if needed. */
static inline int path_has_perm(const struct cred *cred,
1761
				const struct path *path,
E
Eric Paris 已提交
1762 1763
				u32 av)
{
1764
	struct inode *inode = d_backing_inode(path->dentry);
E
Eric Paris 已提交
1765 1766
	struct common_audit_data ad;

1767
	ad.type = LSM_AUDIT_DATA_PATH;
E
Eric Paris 已提交
1768
	ad.u.path = *path;
1769
	__inode_security_revalidate(inode, path->dentry, true);
1770
	return inode_has_perm(cred, inode, av, &ad);
L
Linus Torvalds 已提交
1771 1772
}

1773 1774 1775 1776 1777 1778 1779
/* Same as path_has_perm, but uses the inode from the file struct. */
static inline int file_path_has_perm(const struct cred *cred,
				     struct file *file,
				     u32 av)
{
	struct common_audit_data ad;

1780 1781
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
1782
	return inode_has_perm(cred, file_inode(file), av, &ad);
1783 1784
}

L
Linus Torvalds 已提交
1785 1786 1787 1788 1789 1790 1791 1792
/* 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. */
1793 1794 1795
static int file_has_perm(const struct cred *cred,
			 struct file *file,
			 u32 av)
L
Linus Torvalds 已提交
1796 1797
{
	struct file_security_struct *fsec = file->f_security;
A
Al Viro 已提交
1798
	struct inode *inode = file_inode(file);
1799
	struct common_audit_data ad;
1800
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1801 1802
	int rc;

1803 1804
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
L
Linus Torvalds 已提交
1805

1806 1807
	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid,
L
Linus Torvalds 已提交
1808 1809 1810 1811
				  SECCLASS_FD,
				  FD__USE,
				  &ad);
		if (rc)
1812
			goto out;
L
Linus Torvalds 已提交
1813 1814 1815
	}

	/* av is zero if only checking access to the descriptor. */
1816
	rc = 0;
L
Linus Torvalds 已提交
1817
	if (av)
1818
		rc = inode_has_perm(cred, inode, av, &ad);
L
Linus Torvalds 已提交
1819

1820 1821
out:
	return rc;
L
Linus Torvalds 已提交
1822 1823
}

1824 1825 1826
/*
 * Determine the label for an inode that might be unioned.
 */
1827 1828 1829 1830 1831
static int
selinux_determine_inode_label(const struct task_security_struct *tsec,
				 struct inode *dir,
				 const struct qstr *name, u16 tclass,
				 u32 *_new_isid)
1832 1833 1834 1835 1836 1837 1838 1839 1840 1841
{
	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;

	if ((sbsec->flags & SE_SBINITIALIZED) &&
	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) {
		*_new_isid = sbsec->mntpoint_sid;
	} else if ((sbsec->flags & SBLABEL_MNT) &&
		   tsec->create_sid) {
		*_new_isid = tsec->create_sid;
	} else {
1842
		const struct inode_security_struct *dsec = inode_security(dir);
1843 1844 1845 1846 1847 1848 1849
		return security_transition_sid(tsec->sid, dsec->sid, tclass,
					       name, _new_isid);
	}

	return 0;
}

L
Linus Torvalds 已提交
1850 1851 1852 1853 1854
/* Check whether a task can create a file. */
static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
1855
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
1856 1857
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
1858
	u32 sid, newsid;
1859
	struct common_audit_data ad;
L
Linus Torvalds 已提交
1860 1861
	int rc;

1862
	dsec = inode_security(dir);
L
Linus Torvalds 已提交
1863 1864
	sbsec = dir->i_sb->s_security;

1865 1866
	sid = tsec->sid;

1867
	ad.type = LSM_AUDIT_DATA_DENTRY;
1868
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1869

1870
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1871 1872 1873 1874 1875
			  DIR__ADD_NAME | DIR__SEARCH,
			  &ad);
	if (rc)
		return rc;

1876 1877
	rc = selinux_determine_inode_label(current_security(), dir,
					   &dentry->d_name, tclass, &newsid);
1878 1879
	if (rc)
		return rc;
L
Linus Torvalds 已提交
1880

1881
	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
L
Linus Torvalds 已提交
1882 1883 1884 1885 1886 1887 1888 1889
	if (rc)
		return rc;

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

1890 1891 1892
#define MAY_LINK	0
#define MAY_UNLINK	1
#define MAY_RMDIR	2
L
Linus Torvalds 已提交
1893 1894 1895 1896 1897 1898 1899 1900

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

{
	struct inode_security_struct *dsec, *isec;
1901
	struct common_audit_data ad;
1902
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1903 1904 1905
	u32 av;
	int rc;

1906 1907
	dsec = inode_security(dir);
	isec = backing_inode_security(dentry);
L
Linus Torvalds 已提交
1908

1909
	ad.type = LSM_AUDIT_DATA_DENTRY;
1910
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1911 1912 1913

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1914
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928
	if (rc)
		return rc;

	switch (kind) {
	case MAY_LINK:
		av = FILE__LINK;
		break;
	case MAY_UNLINK:
		av = FILE__UNLINK;
		break;
	case MAY_RMDIR:
		av = DIR__RMDIR;
		break;
	default:
E
Eric Paris 已提交
1929 1930
		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
			__func__, kind);
L
Linus Torvalds 已提交
1931 1932 1933
		return 0;
	}

1934
	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
L
Linus Torvalds 已提交
1935 1936 1937 1938 1939 1940 1941 1942 1943
	return rc;
}

static inline int may_rename(struct inode *old_dir,
			     struct dentry *old_dentry,
			     struct inode *new_dir,
			     struct dentry *new_dentry)
{
	struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1944
	struct common_audit_data ad;
1945
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1946 1947 1948 1949
	u32 av;
	int old_is_dir, new_is_dir;
	int rc;

1950 1951
	old_dsec = inode_security(old_dir);
	old_isec = backing_inode_security(old_dentry);
1952
	old_is_dir = d_is_dir(old_dentry);
1953
	new_dsec = inode_security(new_dir);
L
Linus Torvalds 已提交
1954

1955
	ad.type = LSM_AUDIT_DATA_DENTRY;
L
Linus Torvalds 已提交
1956

1957
	ad.u.dentry = old_dentry;
1958
	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1959 1960 1961
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
1962
	rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1963 1964 1965 1966
			  old_isec->sclass, FILE__RENAME, &ad);
	if (rc)
		return rc;
	if (old_is_dir && new_dir != old_dir) {
1967
		rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1968 1969 1970 1971 1972
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

1973
	ad.u.dentry = new_dentry;
L
Linus Torvalds 已提交
1974
	av = DIR__ADD_NAME | DIR__SEARCH;
1975
	if (d_is_positive(new_dentry))
L
Linus Torvalds 已提交
1976
		av |= DIR__REMOVE_NAME;
1977
	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1978 1979
	if (rc)
		return rc;
1980
	if (d_is_positive(new_dentry)) {
1981
		new_isec = backing_inode_security(new_dentry);
1982
		new_is_dir = d_is_dir(new_dentry);
1983
		rc = avc_has_perm(sid, new_isec->sid,
L
Linus Torvalds 已提交
1984 1985 1986 1987 1988 1989 1990 1991 1992 1993
				  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. */
1994
static int superblock_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1995 1996
			       struct super_block *sb,
			       u32 perms,
1997
			       struct common_audit_data *ad)
L
Linus Torvalds 已提交
1998 1999
{
	struct superblock_security_struct *sbsec;
2000
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
2001 2002

	sbsec = sb->s_security;
2003
	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
L
Linus Torvalds 已提交
2004 2005 2006 2007 2008 2009 2010
}

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

A
Al Viro 已提交
2011
	if (!S_ISDIR(mode)) {
L
Linus Torvalds 已提交
2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033
		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;
}

2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056
/* Convert a Linux file to an access vector. */
static inline u32 file_to_av(struct file *file)
{
	u32 av = 0;

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

	return av;
}

E
Eric Paris 已提交
2057
/*
2058
 * Convert a file to an access vector and include the correct open
E
Eric Paris 已提交
2059 2060
 * open permission.
 */
2061
static inline u32 open_file_to_av(struct file *file)
E
Eric Paris 已提交
2062
{
2063
	u32 av = file_to_av(file);
E
Eric Paris 已提交
2064

2065 2066 2067
	if (selinux_policycap_openperm)
		av |= FILE__OPEN;

E
Eric Paris 已提交
2068 2069 2070
	return av;
}

L
Linus Torvalds 已提交
2071 2072
/* Hook functions begin here. */

2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116
static int selinux_binder_set_context_mgr(struct task_struct *mgr)
{
	u32 mysid = current_sid();
	u32 mgrsid = task_sid(mgr);

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

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

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

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

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

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

static int selinux_binder_transfer_file(struct task_struct *from,
					struct task_struct *to,
					struct file *file)
{
	u32 sid = task_sid(to);
	struct file_security_struct *fsec = file->f_security;
2117
	struct dentry *dentry = file->f_path.dentry;
2118
	struct inode_security_struct *isec;
2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133
	struct common_audit_data ad;
	int rc;

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

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

2134
	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
2135 2136
		return 0;

2137
	isec = backing_inode_security(dentry);
2138 2139 2140 2141
	return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
			    &ad);
}

2142
static int selinux_ptrace_access_check(struct task_struct *child,
2143
				     unsigned int mode)
L
Linus Torvalds 已提交
2144
{
2145 2146 2147 2148
	u32 sid = current_sid();
	u32 csid = task_sid(child);

	if (mode & PTRACE_MODE_READ)
2149
		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
2150

2151
	return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL);
2152 2153 2154 2155
}

static int selinux_ptrace_traceme(struct task_struct *parent)
{
2156 2157
	return avc_has_perm(task_sid(parent), current_sid(), SECCLASS_PROCESS,
			    PROCESS__PTRACE, NULL);
L
Linus Torvalds 已提交
2158 2159 2160
}

static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
2161
			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
L
Linus Torvalds 已提交
2162
{
2163 2164
	return avc_has_perm(current_sid(), task_sid(target), SECCLASS_PROCESS,
			    PROCESS__GETCAP, NULL);
L
Linus Torvalds 已提交
2165 2166
}

D
David Howells 已提交
2167 2168 2169 2170
static int selinux_capset(struct cred *new, const struct cred *old,
			  const kernel_cap_t *effective,
			  const kernel_cap_t *inheritable,
			  const kernel_cap_t *permitted)
L
Linus Torvalds 已提交
2171
{
2172 2173
	return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS,
			    PROCESS__SETCAP, NULL);
L
Linus Torvalds 已提交
2174 2175
}

2176 2177 2178 2179 2180 2181 2182 2183 2184 2185
/*
 * (This comment used to live with the selinux_task_setuid hook,
 * which was removed).
 *
 * Since setuid only affects the current process, and since the SELinux
 * controls are not based on the Linux identity attributes, SELinux does not
 * need to control this operation.  However, SELinux does control the use of
 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
 */

2186 2187
static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
			   int cap, int audit)
L
Linus Torvalds 已提交
2188
{
2189
	return cred_has_capability(cred, cap, audit, ns == &init_user_ns);
L
Linus Torvalds 已提交
2190 2191 2192 2193
}

static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
{
2194
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2195 2196 2197 2198 2199 2200
	int rc = 0;

	if (!sb)
		return 0;

	switch (cmds) {
2201 2202 2203 2204 2205
	case Q_SYNC:
	case Q_QUOTAON:
	case Q_QUOTAOFF:
	case Q_SETINFO:
	case Q_SETQUOTA:
2206
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
2207 2208 2209 2210
		break;
	case Q_GETFMT:
	case Q_GETINFO:
	case Q_GETQUOTA:
2211
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
2212 2213 2214 2215
		break;
	default:
		rc = 0;  /* let the kernel handle invalid cmds */
		break;
L
Linus Torvalds 已提交
2216 2217 2218 2219 2220 2221
	}
	return rc;
}

static int selinux_quota_on(struct dentry *dentry)
{
2222 2223
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2224
	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
L
Linus Torvalds 已提交
2225 2226
}

2227
static int selinux_syslog(int type)
L
Linus Torvalds 已提交
2228 2229
{
	switch (type) {
2230 2231
	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
2232 2233
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL);
2234 2235 2236 2237
	case SYSLOG_ACTION_CONSOLE_OFF:	/* Disable logging to console */
	case SYSLOG_ACTION_CONSOLE_ON:	/* Enable logging to console */
	/* Set level of messages printed to console */
	case SYSLOG_ACTION_CONSOLE_LEVEL:
2238 2239 2240
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE,
				    NULL);
L
Linus Torvalds 已提交
2241
	}
2242 2243 2244
	/* All other syslog types */
	return avc_has_perm(current_sid(), SECINITSID_KERNEL,
			    SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL);
L
Linus Torvalds 已提交
2245 2246 2247 2248 2249 2250 2251 2252 2253 2254
}

/*
 * Check that a process has enough memory to allocate a new virtual
 * mapping. 0 means there is enough memory for the allocation to
 * succeed and -ENOMEM implies there is not.
 *
 * Do not audit the selinux permission check, as this is applied to all
 * processes that allocate mappings.
 */
2255
static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
L
Linus Torvalds 已提交
2256 2257 2258
{
	int rc, cap_sys_admin = 0;

C
Casey Schaufler 已提交
2259
	rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN,
2260
				 SECURITY_CAP_NOAUDIT, true);
L
Linus Torvalds 已提交
2261 2262 2263
	if (rc == 0)
		cap_sys_admin = 1;

C
Casey Schaufler 已提交
2264
	return cap_sys_admin;
L
Linus Torvalds 已提交
2265 2266 2267 2268
}

/* binprm security operations */

2269
static u32 ptrace_parent_sid(void)
2270 2271 2272 2273 2274
{
	u32 sid = 0;
	struct task_struct *tracer;

	rcu_read_lock();
2275
	tracer = ptrace_parent(current);
2276 2277 2278 2279 2280 2281 2282
	if (tracer)
		sid = task_sid(tracer);
	rcu_read_unlock();

	return sid;
}

2283 2284 2285 2286 2287
static int check_nnp_nosuid(const struct linux_binprm *bprm,
			    const struct task_security_struct *old_tsec,
			    const struct task_security_struct *new_tsec)
{
	int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
2288
	int nosuid = !mnt_may_suid(bprm->file->f_path.mnt);
2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317
	int rc;

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

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

	/*
	 * The only transitions we permit under NNP or nosuid
	 * are transitions to bounded SIDs, i.e. SIDs that are
	 * guaranteed to only be allowed a subset of the permissions
	 * of the current SID.
	 */
	rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
	if (rc) {
		/*
		 * On failure, preserve the errno values for NNP vs nosuid.
		 * NNP:  Operation not permitted for caller.
		 * nosuid:  Permission denied to file.
		 */
		if (nnp)
			return -EPERM;
		else
			return -EACCES;
	}
	return 0;
}

2318
static int selinux_bprm_set_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2319
{
2320 2321
	const struct task_security_struct *old_tsec;
	struct task_security_struct *new_tsec;
L
Linus Torvalds 已提交
2322
	struct inode_security_struct *isec;
2323
	struct common_audit_data ad;
A
Al Viro 已提交
2324
	struct inode *inode = file_inode(bprm->file);
L
Linus Torvalds 已提交
2325 2326
	int rc;

2327 2328 2329
	/* SELinux context only depends on initial program or script and not
	 * the script interpreter */
	if (bprm->cred_prepared)
L
Linus Torvalds 已提交
2330 2331
		return 0;

2332 2333
	old_tsec = current_security();
	new_tsec = bprm->cred->security;
2334
	isec = inode_security(inode);
L
Linus Torvalds 已提交
2335 2336

	/* Default to the current task SID. */
2337 2338
	new_tsec->sid = old_tsec->sid;
	new_tsec->osid = old_tsec->sid;
L
Linus Torvalds 已提交
2339

2340
	/* Reset fs, key, and sock SIDs on execve. */
2341 2342 2343
	new_tsec->create_sid = 0;
	new_tsec->keycreate_sid = 0;
	new_tsec->sockcreate_sid = 0;
L
Linus Torvalds 已提交
2344

2345 2346
	if (old_tsec->exec_sid) {
		new_tsec->sid = old_tsec->exec_sid;
L
Linus Torvalds 已提交
2347
		/* Reset exec SID on execve. */
2348
		new_tsec->exec_sid = 0;
2349

2350 2351 2352 2353
		/* Fail on NNP or nosuid if not an allowed transition. */
		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
		if (rc)
			return rc;
L
Linus Torvalds 已提交
2354 2355
	} else {
		/* Check for a default transition on this program. */
2356
		rc = security_transition_sid(old_tsec->sid, isec->sid,
2357 2358
					     SECCLASS_PROCESS, NULL,
					     &new_tsec->sid);
L
Linus Torvalds 已提交
2359 2360
		if (rc)
			return rc;
2361 2362 2363 2364 2365 2366 2367 2368

		/*
		 * Fallback to old SID on NNP or nosuid if not an allowed
		 * transition.
		 */
		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
		if (rc)
			new_tsec->sid = old_tsec->sid;
L
Linus Torvalds 已提交
2369 2370
	}

2371 2372
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = bprm->file;
L
Linus Torvalds 已提交
2373

2374 2375
	if (new_tsec->sid == old_tsec->sid) {
		rc = avc_has_perm(old_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2376 2377 2378 2379 2380
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		/* Check permissions for the transition. */
2381
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
L
Linus Torvalds 已提交
2382 2383 2384 2385
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

2386
		rc = avc_has_perm(new_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2387 2388 2389 2390
				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
		if (rc)
			return rc;

2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401
		/* Check for shared state */
		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
					  SECCLASS_PROCESS, PROCESS__SHARE,
					  NULL);
			if (rc)
				return -EPERM;
		}

		/* Make sure that anyone attempting to ptrace over a task that
		 * changes its SID has the appropriate permit */
2402
		if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
2403
			u32 ptsid = ptrace_parent_sid();
2404 2405 2406 2407 2408 2409 2410 2411
			if (ptsid != 0) {
				rc = avc_has_perm(ptsid, new_tsec->sid,
						  SECCLASS_PROCESS,
						  PROCESS__PTRACE, NULL);
				if (rc)
					return -EPERM;
			}
		}
L
Linus Torvalds 已提交
2412

2413 2414
		/* Clear any possibly unsafe personality bits on exec: */
		bprm->per_clear |= PER_CLEAR_ON_SETID;
L
Linus Torvalds 已提交
2415 2416 2417 2418 2419
	}

	return 0;
}

2420
static int selinux_bprm_secureexec(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2421
{
2422
	const struct task_security_struct *tsec = current_security();
2423
	u32 sid, osid;
L
Linus Torvalds 已提交
2424 2425
	int atsecure = 0;

2426 2427 2428 2429
	sid = tsec->sid;
	osid = tsec->osid;

	if (osid != sid) {
L
Linus Torvalds 已提交
2430 2431 2432
		/* Enable secure mode for SIDs transitions unless
		   the noatsecure permission is granted between
		   the two SIDs, i.e. ahp returns 0. */
2433
		atsecure = avc_has_perm(osid, sid,
2434 2435
					SECCLASS_PROCESS,
					PROCESS__NOATSECURE, NULL);
L
Linus Torvalds 已提交
2436 2437
	}

C
Casey Schaufler 已提交
2438
	return !!atsecure;
L
Linus Torvalds 已提交
2439 2440
}

A
Al Viro 已提交
2441 2442 2443 2444 2445
static int match_file(const void *p, struct file *file, unsigned fd)
{
	return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0;
}

L
Linus Torvalds 已提交
2446
/* Derived from fs/exec.c:flush_old_files. */
2447 2448
static inline void flush_unauthorized_files(const struct cred *cred,
					    struct files_struct *files)
L
Linus Torvalds 已提交
2449 2450
{
	struct file *file, *devnull = NULL;
2451
	struct tty_struct *tty;
2452
	int drop_tty = 0;
A
Al Viro 已提交
2453
	unsigned n;
L
Linus Torvalds 已提交
2454

2455
	tty = get_current_tty();
L
Linus Torvalds 已提交
2456
	if (tty) {
P
Peter Hurley 已提交
2457
		spin_lock(&tty->files_lock);
2458
		if (!list_empty(&tty->tty_files)) {
N
Nick Piggin 已提交
2459
			struct tty_file_private *file_priv;
2460

L
Linus Torvalds 已提交
2461
			/* Revalidate access to controlling tty.
2462 2463 2464 2465
			   Use file_path_has_perm on the tty path directly
			   rather than using file_has_perm, as this particular
			   open file may belong to another process and we are
			   only interested in the inode-based check here. */
N
Nick Piggin 已提交
2466 2467 2468
			file_priv = list_first_entry(&tty->tty_files,
						struct tty_file_private, list);
			file = file_priv->file;
2469
			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2470
				drop_tty = 1;
L
Linus Torvalds 已提交
2471
		}
P
Peter Hurley 已提交
2472
		spin_unlock(&tty->files_lock);
A
Alan Cox 已提交
2473
		tty_kref_put(tty);
L
Linus Torvalds 已提交
2474
	}
2475 2476 2477
	/* Reset controlling tty. */
	if (drop_tty)
		no_tty();
L
Linus Torvalds 已提交
2478 2479

	/* Revalidate access to inherited open files. */
A
Al Viro 已提交
2480 2481 2482
	n = iterate_fd(files, 0, match_file, cred);
	if (!n) /* none found? */
		return;
L
Linus Torvalds 已提交
2483

A
Al Viro 已提交
2484
	devnull = dentry_open(&selinux_null, O_RDWR, cred);
A
Al Viro 已提交
2485 2486 2487 2488 2489 2490 2491
	if (IS_ERR(devnull))
		devnull = NULL;
	/* replace all the matching ones with this */
	do {
		replace_fd(n - 1, devnull, 0);
	} while ((n = iterate_fd(files, n, match_file, cred)) != 0);
	if (devnull)
A
Al Viro 已提交
2492
		fput(devnull);
L
Linus Torvalds 已提交
2493 2494
}

2495 2496 2497 2498
/*
 * Prepare a process for imminent new credential changes due to exec
 */
static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2499
{
2500 2501 2502
	struct task_security_struct *new_tsec;
	struct rlimit *rlim, *initrlim;
	int rc, i;
D
David Howells 已提交
2503

2504 2505 2506
	new_tsec = bprm->cred->security;
	if (new_tsec->sid == new_tsec->osid)
		return;
L
Linus Torvalds 已提交
2507

2508 2509
	/* Close files for which the new task SID is not authorized. */
	flush_unauthorized_files(bprm->cred, current->files);
R
Roland McGrath 已提交
2510

2511 2512
	/* Always clear parent death signal on SID transitions. */
	current->pdeath_signal = 0;
R
Roland McGrath 已提交
2513

2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526
	/* Check whether the new SID can inherit resource limits from the old
	 * SID.  If not, reset all soft limits to the lower of the current
	 * task's hard limit and the init task's soft limit.
	 *
	 * Note that the setting of hard limits (even to lower them) can be
	 * controlled by the setrlimit check.  The inclusion of the init task's
	 * soft limit into the computation is to avoid resetting soft limits
	 * higher than the default soft limit for cases where the default is
	 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
	 */
	rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
			  PROCESS__RLIMITINH, NULL);
	if (rc) {
2527 2528
		/* protect against do_prlimit() */
		task_lock(current);
2529 2530 2531 2532
		for (i = 0; i < RLIM_NLIMITS; i++) {
			rlim = current->signal->rlim + i;
			initrlim = init_task.signal->rlim + i;
			rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
L
Linus Torvalds 已提交
2533
		}
2534
		task_unlock(current);
2535 2536
		if (IS_ENABLED(CONFIG_POSIX_TIMERS))
			update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
L
Linus Torvalds 已提交
2537 2538 2539 2540
	}
}

/*
2541 2542
 * Clean up the process immediately after the installation of new credentials
 * due to exec
L
Linus Torvalds 已提交
2543
 */
2544
static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2545
{
2546
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
2547
	struct itimerval itimer;
2548
	u32 osid, sid;
L
Linus Torvalds 已提交
2549 2550
	int rc, i;

2551 2552 2553 2554
	osid = tsec->osid;
	sid = tsec->sid;

	if (sid == osid)
L
Linus Torvalds 已提交
2555 2556
		return;

2557 2558 2559 2560 2561 2562 2563 2564
	/* Check whether the new SID can inherit signal state from the old SID.
	 * If not, clear itimers to avoid subsequent signal generation and
	 * flush and unblock signals.
	 *
	 * This must occur _after_ the task SID has been updated so that any
	 * kill done after the flush will be checked against the new SID.
	 */
	rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
L
Linus Torvalds 已提交
2565
	if (rc) {
2566 2567 2568 2569 2570
		if (IS_ENABLED(CONFIG_POSIX_TIMERS)) {
			memset(&itimer, 0, sizeof itimer);
			for (i = 0; i < 3; i++)
				do_setitimer(i, &itimer, NULL);
		}
L
Linus Torvalds 已提交
2571
		spin_lock_irq(&current->sighand->siglock);
2572 2573 2574
		if (!fatal_signal_pending(current)) {
			flush_sigqueue(&current->pending);
			flush_sigqueue(&current->signal->shared_pending);
2575 2576
			flush_signal_handlers(current, 1);
			sigemptyset(&current->blocked);
2577
			recalc_sigpending();
2578
		}
L
Linus Torvalds 已提交
2579 2580 2581
		spin_unlock_irq(&current->sighand->siglock);
	}

2582 2583
	/* Wake up the parent if it is waiting so that it can recheck
	 * wait permission to the new task SID. */
2584
	read_lock(&tasklist_lock);
2585
	__wake_up_parent(current, current->real_parent);
2586
	read_unlock(&tasklist_lock);
L
Linus Torvalds 已提交
2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610
}

/* 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)
{
2611 2612 2613
	return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
		match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
		match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2614 2615
		match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
		match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
L
Linus Torvalds 已提交
2616 2617 2618 2619 2620 2621 2622
}

static inline void take_option(char **to, char *from, int *first, int len)
{
	if (!*first) {
		**to = ',';
		*to += 1;
2623
	} else
L
Linus Torvalds 已提交
2624 2625 2626 2627 2628
		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}

2629 2630
static inline void take_selinux_option(char **to, char *from, int *first,
				       int len)
2631 2632 2633 2634 2635 2636
{
	int current_size = 0;

	if (!*first) {
		**to = '|';
		*to += 1;
2637
	} else
2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649
		*first = 0;

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

2650
static int selinux_sb_copy_data(char *orig, char *copy)
L
Linus Torvalds 已提交
2651 2652 2653 2654
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_curr, *in_end;
	char *sec_curr, *nosec_save, *nosec;
2655
	int open_quote = 0;
L
Linus Torvalds 已提交
2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670

	in_curr = orig;
	sec_curr = copy;

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

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

	do {
2671 2672 2673 2674
		if (*in_end == '"')
			open_quote = !open_quote;
		if ((*in_end == ',' && open_quote == 0) ||
				*in_end == '\0') {
L
Linus Torvalds 已提交
2675 2676 2677
			int len = in_end - in_curr;

			if (selinux_option(in_curr, len))
2678
				take_selinux_option(&sec_curr, in_curr, &fsec, len);
L
Linus Torvalds 已提交
2679 2680 2681 2682 2683 2684 2685
			else
				take_option(&nosec, in_curr, &fnosec, len);

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

2686
	strcpy(in_save, nosec_save);
2687
	free_page((unsigned long)nosec_save);
L
Linus Torvalds 已提交
2688 2689 2690 2691
out:
	return rc;
}

2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725
static int selinux_sb_remount(struct super_block *sb, void *data)
{
	int rc, i, *flags;
	struct security_mnt_opts opts;
	char *secdata, **mount_options;
	struct superblock_security_struct *sbsec = sb->s_security;

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

	if (!data)
		return 0;

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

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

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

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

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

2726
		if (flags[i] == SBLABEL_MNT)
2727
			continue;
2728
		rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL);
2729
		if (rc) {
2730
			printk(KERN_WARNING "SELinux: security_context_str_to_sid"
2731 2732
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, sb->s_type->name, rc);
2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746
			goto out_free_opts;
		}
		rc = -EINVAL;
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
				goto out_bad_option;
			break;
		case CONTEXT_MNT:
			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
				goto out_bad_option;
			break;
		case ROOTCONTEXT_MNT: {
			struct inode_security_struct *root_isec;
2747
			root_isec = backing_inode_security(sb->s_root);
2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769

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

	rc = 0;
out_free_opts:
	security_free_mnt_opts(&opts);
out_free_secdata:
	free_secdata(secdata);
	return rc;
out_bad_option:
	printk(KERN_WARNING "SELinux: unable to change security options "
2770 2771
	       "during remount (dev %s, type=%s)\n", sb->s_id,
	       sb->s_type->name);
2772 2773 2774
	goto out_free_opts;
}

2775
static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
L
Linus Torvalds 已提交
2776
{
2777
	const struct cred *cred = current_cred();
2778
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2779 2780 2781 2782 2783 2784
	int rc;

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

2785 2786 2787 2788
	/* Allow all mounts performed by the kernel */
	if (flags & MS_KERNMOUNT)
		return 0;

2789
	ad.type = LSM_AUDIT_DATA_DENTRY;
2790
	ad.u.dentry = sb->s_root;
2791
	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
L
Linus Torvalds 已提交
2792 2793
}

2794
static int selinux_sb_statfs(struct dentry *dentry)
L
Linus Torvalds 已提交
2795
{
2796
	const struct cred *cred = current_cred();
2797
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2798

2799
	ad.type = LSM_AUDIT_DATA_DENTRY;
2800
	ad.u.dentry = dentry->d_sb->s_root;
2801
	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
L
Linus Torvalds 已提交
2802 2803
}

A
Al Viro 已提交
2804
static int selinux_mount(const char *dev_name,
A
Al Viro 已提交
2805
			 const struct path *path,
A
Al Viro 已提交
2806
			 const char *type,
2807 2808
			 unsigned long flags,
			 void *data)
L
Linus Torvalds 已提交
2809
{
2810
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2811 2812

	if (flags & MS_REMOUNT)
2813
		return superblock_has_perm(cred, path->dentry->d_sb,
2814
					   FILESYSTEM__REMOUNT, NULL);
L
Linus Torvalds 已提交
2815
	else
E
Eric Paris 已提交
2816
		return path_has_perm(cred, path, FILE__MOUNTON);
L
Linus Torvalds 已提交
2817 2818 2819 2820
}

static int selinux_umount(struct vfsmount *mnt, int flags)
{
2821
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2822

2823
	return superblock_has_perm(cred, mnt->mnt_sb,
2824
				   FILESYSTEM__UNMOUNT, NULL);
L
Linus Torvalds 已提交
2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838
}

/* 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);
}

2839
static int selinux_dentry_init_security(struct dentry *dentry, int mode,
A
Al Viro 已提交
2840
					const struct qstr *name, void **ctx,
2841 2842 2843 2844 2845
					u32 *ctxlen)
{
	u32 newsid;
	int rc;

2846 2847
	rc = selinux_determine_inode_label(current_security(),
					   d_inode(dentry->d_parent), name,
2848 2849 2850 2851
					   inode_mode_to_security_class(mode),
					   &newsid);
	if (rc)
		return rc;
2852 2853 2854 2855

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

2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876
static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
					  struct qstr *name,
					  const struct cred *old,
					  struct cred *new)
{
	u32 newsid;
	int rc;
	struct task_security_struct *tsec;

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

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

2877
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2878 2879
				       const struct qstr *qstr,
				       const char **name,
2880
				       void **value, size_t *len)
2881
{
2882
	const struct task_security_struct *tsec = current_security();
2883
	struct superblock_security_struct *sbsec;
2884
	u32 sid, newsid, clen;
2885
	int rc;
2886
	char *context;
2887 2888 2889

	sbsec = dir->i_sb->s_security;

2890 2891 2892
	sid = tsec->sid;
	newsid = tsec->create_sid;

2893
	rc = selinux_determine_inode_label(current_security(),
2894 2895 2896 2897 2898
		dir, qstr,
		inode_mode_to_security_class(inode->i_mode),
		&newsid);
	if (rc)
		return rc;
2899

2900
	/* Possibly defer initialization to selinux_complete_init. */
2901
	if (sbsec->flags & SE_SBINITIALIZED) {
2902 2903 2904
		struct inode_security_struct *isec = inode->i_security;
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		isec->sid = newsid;
2905
		isec->initialized = LABEL_INITIALIZED;
2906
	}
2907

2908
	if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
2909 2910
		return -EOPNOTSUPP;

2911 2912
	if (name)
		*name = XATTR_SELINUX_SUFFIX;
2913

2914
	if (value && len) {
2915
		rc = security_sid_to_context_force(newsid, &context, &clen);
2916
		if (rc)
2917 2918 2919
			return rc;
		*value = context;
		*len = clen;
2920 2921 2922 2923 2924
	}

	return 0;
}

A
Al Viro 已提交
2925
static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944
{
	return may_create(dir, dentry, SECCLASS_FILE);
}

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

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

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

2945
static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
L
Linus Torvalds 已提交
2946 2947 2948 2949 2950 2951 2952 2953 2954
{
	return may_create(dir, dentry, SECCLASS_DIR);
}

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

A
Al Viro 已提交
2955
static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
L
Linus Torvalds 已提交
2956 2957 2958 2959 2960
{
	return may_create(dir, dentry, inode_mode_to_security_class(mode));
}

static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2961
				struct inode *new_inode, struct dentry *new_dentry)
L
Linus Torvalds 已提交
2962 2963 2964 2965 2966 2967
{
	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
}

static int selinux_inode_readlink(struct dentry *dentry)
{
2968 2969
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2970
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
2971 2972
}

2973 2974
static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
				     bool rcu)
L
Linus Torvalds 已提交
2975
{
2976
	const struct cred *cred = current_cred();
2977 2978 2979
	struct common_audit_data ad;
	struct inode_security_struct *isec;
	u32 sid;
L
Linus Torvalds 已提交
2980

2981 2982 2983 2984 2985
	validate_creds(cred);

	ad.type = LSM_AUDIT_DATA_DENTRY;
	ad.u.dentry = dentry;
	sid = cred_sid(cred);
2986 2987 2988
	isec = inode_security_rcu(inode, rcu);
	if (IS_ERR(isec))
		return PTR_ERR(isec);
2989 2990 2991

	return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad,
				  rcu ? MAY_NOT_BLOCK : 0);
L
Linus Torvalds 已提交
2992 2993
}

2994 2995
static noinline int audit_inode_permission(struct inode *inode,
					   u32 perms, u32 audited, u32 denied,
2996
					   int result,
2997
					   unsigned flags)
L
Linus Torvalds 已提交
2998
{
2999
	struct common_audit_data ad;
3000 3001 3002
	struct inode_security_struct *isec = inode->i_security;
	int rc;

3003
	ad.type = LSM_AUDIT_DATA_INODE;
3004 3005 3006
	ad.u.inode = inode;

	rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms,
3007
			    audited, denied, result, &ad, flags);
3008 3009 3010 3011 3012
	if (rc)
		return rc;
	return 0;
}

3013
static int selinux_inode_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
3014
{
3015
	const struct cred *cred = current_cred();
3016 3017
	u32 perms;
	bool from_access;
3018
	unsigned flags = mask & MAY_NOT_BLOCK;
3019 3020 3021 3022 3023
	struct inode_security_struct *isec;
	u32 sid;
	struct av_decision avd;
	int rc, rc2;
	u32 audited, denied;
L
Linus Torvalds 已提交
3024

3025
	from_access = mask & MAY_ACCESS;
3026 3027
	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);

3028 3029
	/* No permission to check.  Existence test. */
	if (!mask)
L
Linus Torvalds 已提交
3030 3031
		return 0;

3032
	validate_creds(cred);
3033

3034 3035
	if (unlikely(IS_PRIVATE(inode)))
		return 0;
3036 3037 3038

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

3039
	sid = cred_sid(cred);
3040 3041 3042
	isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK);
	if (IS_ERR(isec))
		return PTR_ERR(isec);
3043 3044 3045 3046 3047 3048 3049 3050

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

3051
	rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
3052 3053 3054
	if (rc2)
		return rc2;
	return rc;
L
Linus Torvalds 已提交
3055 3056 3057 3058
}

static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
3059
	const struct cred *cred = current_cred();
3060
	unsigned int ia_valid = iattr->ia_valid;
3061
	__u32 av = FILE__WRITE;
L
Linus Torvalds 已提交
3062

3063 3064 3065 3066 3067 3068 3069
	/* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
	if (ia_valid & ATTR_FORCE) {
		ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
			      ATTR_FORCE);
		if (!ia_valid)
			return 0;
	}
L
Linus Torvalds 已提交
3070

3071 3072
	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
E
Eric Paris 已提交
3073
		return dentry_has_perm(cred, dentry, FILE__SETATTR);
L
Linus Torvalds 已提交
3074

3075 3076
	if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE)
			&& !(ia_valid & ATTR_FILE))
3077 3078 3079
		av |= FILE__OPEN;

	return dentry_has_perm(cred, dentry, av);
L
Linus Torvalds 已提交
3080 3081
}

3082
static int selinux_inode_getattr(const struct path *path)
L
Linus Torvalds 已提交
3083
{
3084
	return path_has_perm(current_cred(), path, FILE__GETATTR);
L
Linus Torvalds 已提交
3085 3086
}

3087
static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
3088
{
3089 3090
	const struct cred *cred = current_cred();

3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104
	if (!strncmp(name, XATTR_SECURITY_PREFIX,
		     sizeof XATTR_SECURITY_PREFIX - 1)) {
		if (!strcmp(name, XATTR_NAME_CAPS)) {
			if (!capable(CAP_SETFCAP))
				return -EPERM;
		} else if (!capable(CAP_SYS_ADMIN)) {
			/* A different attribute in the security namespace.
			   Restrict to administrator. */
			return -EPERM;
		}
	}

	/* Not an attribute we recognize, so just check the
	   ordinary setattr permission. */
E
Eric Paris 已提交
3105
	return dentry_has_perm(cred, dentry, FILE__SETATTR);
3106 3107
}

3108 3109
static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
				  const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
3110
{
3111
	struct inode *inode = d_backing_inode(dentry);
3112
	struct inode_security_struct *isec;
L
Linus Torvalds 已提交
3113
	struct superblock_security_struct *sbsec;
3114
	struct common_audit_data ad;
3115
	u32 newsid, sid = current_sid();
L
Linus Torvalds 已提交
3116 3117
	int rc = 0;

3118 3119
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
3120 3121

	sbsec = inode->i_sb->s_security;
3122
	if (!(sbsec->flags & SBLABEL_MNT))
L
Linus Torvalds 已提交
3123 3124
		return -EOPNOTSUPP;

3125
	if (!inode_owner_or_capable(inode))
L
Linus Torvalds 已提交
3126 3127
		return -EPERM;

3128
	ad.type = LSM_AUDIT_DATA_DENTRY;
3129
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
3130

3131
	isec = backing_inode_security(dentry);
3132
	rc = avc_has_perm(sid, isec->sid, isec->sclass,
L
Linus Torvalds 已提交
3133 3134 3135 3136
			  FILE__RELABELFROM, &ad);
	if (rc)
		return rc;

3137
	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
3138
	if (rc == -EINVAL) {
3139 3140 3141 3142 3143 3144 3145
		if (!capable(CAP_MAC_ADMIN)) {
			struct audit_buffer *ab;
			size_t audit_size;
			const char *str;

			/* We strip a nul only if it is at the end, otherwise the
			 * context contains a nul and we should audit that */
3146 3147 3148 3149 3150 3151 3152 3153 3154 3155
			if (value) {
				str = value;
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
			} else {
				str = "";
				audit_size = 0;
			}
3156 3157 3158 3159 3160
			ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
			audit_log_format(ab, "op=setxattr invalid_context=");
			audit_log_n_untrustedstring(ab, value, audit_size);
			audit_log_end(ab);

3161
			return rc;
3162
		}
3163 3164
		rc = security_context_to_sid_force(value, size, &newsid);
	}
L
Linus Torvalds 已提交
3165 3166 3167
	if (rc)
		return rc;

3168
	rc = avc_has_perm(sid, newsid, isec->sclass,
L
Linus Torvalds 已提交
3169 3170 3171 3172
			  FILE__RELABELTO, &ad);
	if (rc)
		return rc;

3173
	rc = security_validate_transition(isec->sid, newsid, sid,
3174
					  isec->sclass);
L
Linus Torvalds 已提交
3175 3176 3177 3178 3179 3180 3181 3182 3183 3184
	if (rc)
		return rc;

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

3185
static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
3186
					const void *value, size_t size,
3187
					int flags)
L
Linus Torvalds 已提交
3188
{
3189
	struct inode *inode = d_backing_inode(dentry);
3190
	struct inode_security_struct *isec;
L
Linus Torvalds 已提交
3191 3192 3193 3194 3195 3196 3197 3198
	u32 newsid;
	int rc;

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

3199
	rc = security_context_to_sid_force(value, size, &newsid);
L
Linus Torvalds 已提交
3200
	if (rc) {
3201 3202 3203
		printk(KERN_ERR "SELinux:  unable to map context to SID"
		       "for (%s, %lu), rc=%d\n",
		       inode->i_sb->s_id, inode->i_ino, -rc);
L
Linus Torvalds 已提交
3204 3205 3206
		return;
	}

3207
	isec = backing_inode_security(dentry);
3208
	spin_lock(&isec->lock);
3209
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
3210
	isec->sid = newsid;
3211
	isec->initialized = LABEL_INITIALIZED;
3212
	spin_unlock(&isec->lock);
3213

L
Linus Torvalds 已提交
3214 3215 3216
	return;
}

3217
static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
3218
{
3219 3220
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
3221
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
3222 3223
}

3224
static int selinux_inode_listxattr(struct dentry *dentry)
L
Linus Torvalds 已提交
3225
{
3226 3227
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
3228
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
3229 3230
}

3231
static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
3232
{
3233 3234
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
3235 3236 3237 3238 3239 3240

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

3241
/*
3242
 * Copy the inode security context value to the user.
3243 3244 3245
 *
 * Permission check is handled by selinux_inode_getxattr hook.
 */
3246
static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc)
L
Linus Torvalds 已提交
3247
{
3248 3249 3250
	u32 size;
	int error;
	char *context = NULL;
3251
	struct inode_security_struct *isec;
3252

3253 3254
	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;
3255

3256 3257 3258 3259 3260 3261 3262 3263 3264
	/*
	 * If the caller has CAP_MAC_ADMIN, then get the raw context
	 * value even if it is not defined by current policy; otherwise,
	 * use the in-core value under current policy.
	 * Use the non-auditing forms of the permission checks since
	 * getxattr may be called by unprivileged processes commonly
	 * and lack of permission just means that we fall back to the
	 * in-core context value, not a denial.
	 */
C
Casey Schaufler 已提交
3265 3266 3267 3268
	error = cap_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
			    SECURITY_CAP_NOAUDIT);
	if (!error)
		error = cred_has_capability(current_cred(), CAP_MAC_ADMIN,
3269
					    SECURITY_CAP_NOAUDIT, true);
3270
	isec = inode_security(inode);
3271 3272 3273 3274 3275
	if (!error)
		error = security_sid_to_context_force(isec->sid, &context,
						      &size);
	else
		error = security_sid_to_context(isec->sid, &context, &size);
3276 3277 3278 3279 3280 3281 3282 3283 3284 3285
	if (error)
		return error;
	error = size;
	if (alloc) {
		*buffer = context;
		goto out_nofree;
	}
	kfree(context);
out_nofree:
	return error;
L
Linus Torvalds 已提交
3286 3287 3288
}

static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3289
				     const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
3290
{
3291
	struct inode_security_struct *isec = inode_security_novalidate(inode);
L
Linus Torvalds 已提交
3292 3293 3294 3295 3296 3297 3298 3299 3300
	u32 newsid;
	int rc;

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

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

3301
	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
L
Linus Torvalds 已提交
3302 3303 3304
	if (rc)
		return rc;

3305
	spin_lock(&isec->lock);
3306
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
3307
	isec->sid = newsid;
3308
	isec->initialized = LABEL_INITIALIZED;
3309
	spin_unlock(&isec->lock);
L
Linus Torvalds 已提交
3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320
	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;
}

3321
static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
3322
{
3323
	struct inode_security_struct *isec = inode_security_novalidate(inode);
3324 3325 3326
	*secid = isec->sid;
}

3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346
static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
{
	u32 sid;
	struct task_security_struct *tsec;
	struct cred *new_creds = *new;

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

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

3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361
static int selinux_inode_copy_up_xattr(const char *name)
{
	/* The copy_up hook above sets the initial context on an inode, but we
	 * don't then want to overwrite it by blindly copying all the lower
	 * xattrs up.  Instead, we have to filter out SELinux-related xattrs.
	 */
	if (strcmp(name, XATTR_NAME_SELINUX) == 0)
		return 1; /* Discard */
	/*
	 * Any other attribute apart from SELINUX is not claimed, supported
	 * by selinux.
	 */
	return -EOPNOTSUPP;
}

L
Linus Torvalds 已提交
3362 3363
/* file security operations */

3364
static int selinux_revalidate_file_permission(struct file *file, int mask)
L
Linus Torvalds 已提交
3365
{
3366
	const struct cred *cred = current_cred();
A
Al Viro 已提交
3367
	struct inode *inode = file_inode(file);
L
Linus Torvalds 已提交
3368 3369 3370 3371 3372

	/* 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;

3373 3374
	return file_has_perm(cred, file,
			     file_mask_to_av(inode->i_mode, mask));
L
Linus Torvalds 已提交
3375 3376
}

3377 3378
static int selinux_file_permission(struct file *file, int mask)
{
A
Al Viro 已提交
3379
	struct inode *inode = file_inode(file);
3380
	struct file_security_struct *fsec = file->f_security;
3381
	struct inode_security_struct *isec;
3382 3383
	u32 sid = current_sid();

3384
	if (!mask)
3385 3386 3387
		/* No permission to check.  Existence test. */
		return 0;

3388
	isec = inode_security(inode);
3389 3390
	if (sid == fsec->sid && fsec->isid == isec->sid &&
	    fsec->pseqno == avc_policy_seqno())
3391
		/* No change since file_open check. */
3392 3393
		return 0;

3394 3395 3396
	return selinux_revalidate_file_permission(file, mask);
}

L
Linus Torvalds 已提交
3397 3398 3399 3400 3401 3402 3403 3404 3405 3406
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);
}

3407 3408 3409 3410
/*
 * Check whether a task has the ioctl permission and cmd
 * operation to an inode.
 */
3411
static int ioctl_has_perm(const struct cred *cred, struct file *file,
3412 3413 3414 3415 3416
		u32 requested, u16 cmd)
{
	struct common_audit_data ad;
	struct file_security_struct *fsec = file->f_security;
	struct inode *inode = file_inode(file);
3417
	struct inode_security_struct *isec;
3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440
	struct lsm_ioctlop_audit ioctl;
	u32 ssid = cred_sid(cred);
	int rc;
	u8 driver = cmd >> 8;
	u8 xperm = cmd & 0xff;

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

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

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

3441
	isec = inode_security(inode);
3442 3443 3444 3445 3446 3447
	rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass,
			requested, driver, xperm, &ad);
out:
	return rc;
}

L
Linus Torvalds 已提交
3448 3449 3450
static int selinux_file_ioctl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3451
	const struct cred *cred = current_cred();
3452
	int error = 0;
L
Linus Torvalds 已提交
3453

3454 3455 3456 3457 3458 3459 3460
	switch (cmd) {
	case FIONREAD:
	/* fall through */
	case FIBMAP:
	/* fall through */
	case FIGETBSZ:
	/* fall through */
3461
	case FS_IOC_GETFLAGS:
3462
	/* fall through */
3463
	case FS_IOC_GETVERSION:
3464 3465
		error = file_has_perm(cred, file, FILE__GETATTR);
		break;
L
Linus Torvalds 已提交
3466

3467
	case FS_IOC_SETFLAGS:
3468
	/* fall through */
3469
	case FS_IOC_SETVERSION:
3470 3471 3472 3473 3474 3475 3476 3477 3478
		error = file_has_perm(cred, file, FILE__SETATTR);
		break;

	/* sys_ioctl() checks */
	case FIONBIO:
	/* fall through */
	case FIOASYNC:
		error = file_has_perm(cred, file, 0);
		break;
L
Linus Torvalds 已提交
3479

3480 3481
	case KDSKBENT:
	case KDSKBSENT:
3482
		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3483
					    SECURITY_CAP_AUDIT, true);
3484 3485 3486 3487 3488 3489
		break;

	/* default case assumes that the command will go
	 * to the file's ioctl() function.
	 */
	default:
3490
		error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd);
3491 3492
	}
	return error;
L
Linus Torvalds 已提交
3493 3494
}

3495 3496
static int default_noexec;

L
Linus Torvalds 已提交
3497 3498
static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
3499
	const struct cred *cred = current_cred();
3500
	u32 sid = cred_sid(cred);
D
David Howells 已提交
3501
	int rc = 0;
3502

3503
	if (default_noexec &&
3504 3505
	    (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) ||
				   (!shared && (prot & PROT_WRITE)))) {
L
Linus Torvalds 已提交
3506 3507 3508 3509 3510
		/*
		 * We are making executable an anonymous mapping or a
		 * private file mapping that will also be writable.
		 * This has an additional check.
		 */
3511 3512
		rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
				  PROCESS__EXECMEM, NULL);
L
Linus Torvalds 已提交
3513
		if (rc)
D
David Howells 已提交
3514
			goto error;
L
Linus Torvalds 已提交
3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527
	}

	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;

3528
		return file_has_perm(cred, file, av);
L
Linus Torvalds 已提交
3529
	}
D
David Howells 已提交
3530 3531 3532

error:
	return rc;
L
Linus Torvalds 已提交
3533 3534
}

3535
static int selinux_mmap_addr(unsigned long addr)
L
Linus Torvalds 已提交
3536
{
C
Casey Schaufler 已提交
3537
	int rc = 0;
L
Linus Torvalds 已提交
3538

3539
	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3540
		u32 sid = current_sid();
3541 3542
		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
				  MEMPROTECT__MMAP_ZERO, NULL);
3543 3544
	}

3545
	return rc;
3546
}
L
Linus Torvalds 已提交
3547

3548 3549 3550
static int selinux_mmap_file(struct file *file, unsigned long reqprot,
			     unsigned long prot, unsigned long flags)
{
L
Linus Torvalds 已提交
3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561
	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)
{
3562
	const struct cred *cred = current_cred();
3563
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
3564 3565 3566 3567

	if (selinux_checkreqprot)
		prot = reqprot;

3568 3569
	if (default_noexec &&
	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3570
		int rc = 0;
3571 3572
		if (vma->vm_start >= vma->vm_mm->start_brk &&
		    vma->vm_end <= vma->vm_mm->brk) {
3573 3574
			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
					  PROCESS__EXECHEAP, NULL);
3575
		} else if (!vma->vm_file &&
3576 3577
			   ((vma->vm_start <= vma->vm_mm->start_stack &&
			     vma->vm_end >= vma->vm_mm->start_stack) ||
3578
			    vma_is_stack_for_current(vma))) {
3579 3580
			rc = avc_has_perm(sid, sid, SECCLASS_PROCESS,
					  PROCESS__EXECSTACK, NULL);
3581 3582 3583 3584 3585 3586 3587 3588
		} else if (vma->vm_file && vma->anon_vma) {
			/*
			 * We are making executable a file mapping that has
			 * had some COW done. Since pages might have been
			 * written, check ability to execute the possibly
			 * modified content.  This typically should only
			 * occur for text relocations.
			 */
D
David Howells 已提交
3589
			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3590
		}
3591 3592 3593
		if (rc)
			return rc;
	}
L
Linus Torvalds 已提交
3594 3595 3596 3597 3598 3599

	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)
{
3600 3601 3602
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, FILE__LOCK);
L
Linus Torvalds 已提交
3603 3604 3605 3606 3607
}

static int selinux_file_fcntl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3608
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3609 3610 3611
	int err = 0;

	switch (cmd) {
3612 3613
	case F_SETFL:
		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3614
			err = file_has_perm(cred, file, FILE__WRITE);
L
Linus Torvalds 已提交
3615
			break;
3616 3617 3618 3619 3620 3621 3622
		}
		/* fall through */
	case F_SETOWN:
	case F_SETSIG:
	case F_GETFL:
	case F_GETOWN:
	case F_GETSIG:
3623
	case F_GETOWNER_UIDS:
3624
		/* Just check FD__USE permission */
3625
		err = file_has_perm(cred, file, 0);
3626 3627 3628 3629
		break;
	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
3630 3631 3632
	case F_OFD_GETLK:
	case F_OFD_SETLK:
	case F_OFD_SETLKW:
L
Linus Torvalds 已提交
3633
#if BITS_PER_LONG == 32
3634 3635 3636
	case F_GETLK64:
	case F_SETLK64:
	case F_SETLKW64:
L
Linus Torvalds 已提交
3637
#endif
3638
		err = file_has_perm(cred, file, FILE__LOCK);
3639
		break;
L
Linus Torvalds 已提交
3640 3641 3642 3643 3644
	}

	return err;
}

3645
static void selinux_file_set_fowner(struct file *file)
L
Linus Torvalds 已提交
3646 3647 3648 3649
{
	struct file_security_struct *fsec;

	fsec = file->f_security;
3650
	fsec->fown_sid = current_sid();
L
Linus Torvalds 已提交
3651 3652 3653 3654 3655
}

static int selinux_file_send_sigiotask(struct task_struct *tsk,
				       struct fown_struct *fown, int signum)
{
3656
	struct file *file;
3657
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
3658 3659 3660 3661
	u32 perm;
	struct file_security_struct *fsec;

	/* struct fown_struct is never outside the context of a struct file */
3662
	file = container_of(fown, struct file, f_owner);
L
Linus Torvalds 已提交
3663 3664 3665 3666 3667 3668 3669 3670

	fsec = file->f_security;

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

3671
	return avc_has_perm(fsec->fown_sid, sid,
L
Linus Torvalds 已提交
3672 3673 3674 3675 3676
			    SECCLASS_PROCESS, perm, NULL);
}

static int selinux_file_receive(struct file *file)
{
3677 3678 3679
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, file_to_av(file));
L
Linus Torvalds 已提交
3680 3681
}

3682
static int selinux_file_open(struct file *file, const struct cred *cred)
3683 3684 3685
{
	struct file_security_struct *fsec;
	struct inode_security_struct *isec;
D
David Howells 已提交
3686

3687
	fsec = file->f_security;
3688
	isec = inode_security(file_inode(file));
3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705
	/*
	 * Save inode label and policy sequence number
	 * at open-time so that selinux_file_permission
	 * can determine whether revalidation is necessary.
	 * Task label is already saved in the file security
	 * struct as its SID.
	 */
	fsec->isid = isec->sid;
	fsec->pseqno = avc_policy_seqno();
	/*
	 * Since the inode label or policy seqno may have changed
	 * between the selinux_inode_permission check and the saving
	 * of state above, recheck that access is still permitted.
	 * Otherwise, access might never be revalidated against the
	 * new inode label or new policy.
	 * This check is not redundant - do not remove.
	 */
3706
	return file_path_has_perm(cred, file, open_file_to_av(file));
3707 3708
}

L
Linus Torvalds 已提交
3709 3710 3711 3712
/* task security operations */

static int selinux_task_create(unsigned long clone_flags)
{
3713 3714 3715
	u32 sid = current_sid();

	return avc_has_perm(sid, sid, SECCLASS_PROCESS, PROCESS__FORK, NULL);
L
Linus Torvalds 已提交
3716 3717
}

3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732
/*
 * allocate the SELinux part of blank credentials
 */
static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
{
	struct task_security_struct *tsec;

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

	cred->security = tsec;
	return 0;
}

D
David Howells 已提交
3733 3734 3735 3736
/*
 * detach and free the LSM part of a set of credentials
 */
static void selinux_cred_free(struct cred *cred)
L
Linus Torvalds 已提交
3737
{
D
David Howells 已提交
3738
	struct task_security_struct *tsec = cred->security;
3739

3740 3741 3742 3743 3744
	/*
	 * cred->security == NULL if security_cred_alloc_blank() or
	 * security_prepare_creds() returned an error.
	 */
	BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3745
	cred->security = (void *) 0x7UL;
D
David Howells 已提交
3746 3747
	kfree(tsec);
}
L
Linus Torvalds 已提交
3748

D
David Howells 已提交
3749 3750 3751 3752 3753 3754 3755 3756
/*
 * prepare a new set of credentials for modification
 */
static int selinux_cred_prepare(struct cred *new, const struct cred *old,
				gfp_t gfp)
{
	const struct task_security_struct *old_tsec;
	struct task_security_struct *tsec;
L
Linus Torvalds 已提交
3757

D
David Howells 已提交
3758
	old_tsec = old->security;
L
Linus Torvalds 已提交
3759

D
David Howells 已提交
3760 3761 3762
	tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
	if (!tsec)
		return -ENOMEM;
L
Linus Torvalds 已提交
3763

D
David Howells 已提交
3764
	new->security = tsec;
L
Linus Torvalds 已提交
3765 3766 3767
	return 0;
}

3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778
/*
 * transfer the SELinux data to a blank set of creds
 */
static void selinux_cred_transfer(struct cred *new, const struct cred *old)
{
	const struct task_security_struct *old_tsec = old->security;
	struct task_security_struct *tsec = new->security;

	*tsec = *old_tsec;
}

3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807
/*
 * set the security data for a kernel service
 * - all the creation contexts are set to unlabelled
 */
static int selinux_kernel_act_as(struct cred *new, u32 secid)
{
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

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

/*
 * set the file creation context in a security record to the same as the
 * objective context of the specified inode
 */
static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
{
3808
	struct inode_security_struct *isec = inode_security(inode);
3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

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

	if (ret == 0)
		tsec->create_sid = isec->sid;
3820
	return ret;
3821 3822
}

3823
static int selinux_kernel_module_request(char *kmod_name)
3824
{
3825 3826
	struct common_audit_data ad;

3827
	ad.type = LSM_AUDIT_DATA_KMOD;
3828 3829
	ad.u.kmod_name = kmod_name;

3830
	return avc_has_perm(current_sid(), SECINITSID_KERNEL, SECCLASS_SYSTEM,
3831
			    SYSTEM__MODULE_REQUEST, &ad);
3832 3833
}

3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847
static int selinux_kernel_module_from_file(struct file *file)
{
	struct common_audit_data ad;
	struct inode_security_struct *isec;
	struct file_security_struct *fsec;
	u32 sid = current_sid();
	int rc;

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

	/* finit_module */
3848

3849 3850
	ad.type = LSM_AUDIT_DATA_FILE;
	ad.u.file = file;
3851 3852 3853 3854 3855 3856 3857 3858

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

3859
	isec = inode_security(file_inode(file));
3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879
	return avc_has_perm(sid, isec->sid, SECCLASS_SYSTEM,
				SYSTEM__MODULE_LOAD, &ad);
}

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

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

	return rc;
}

L
Linus Torvalds 已提交
3880 3881
static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
{
3882 3883
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETPGID, NULL);
L
Linus Torvalds 已提交
3884 3885 3886 3887
}

static int selinux_task_getpgid(struct task_struct *p)
{
3888 3889
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__GETPGID, NULL);
L
Linus Torvalds 已提交
3890 3891 3892 3893
}

static int selinux_task_getsid(struct task_struct *p)
{
3894 3895
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__GETSESSION, NULL);
L
Linus Torvalds 已提交
3896 3897
}

3898 3899
static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
{
3900
	*secid = task_sid(p);
3901 3902
}

L
Linus Torvalds 已提交
3903 3904
static int selinux_task_setnice(struct task_struct *p, int nice)
{
3905 3906
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETSCHED, NULL);
L
Linus Torvalds 已提交
3907 3908
}

3909 3910
static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
3911 3912
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETSCHED, NULL);
3913 3914
}

3915 3916
static int selinux_task_getioprio(struct task_struct *p)
{
3917 3918
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__GETSCHED, NULL);
3919 3920
}

3921 3922
static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
		struct rlimit *new_rlim)
L
Linus Torvalds 已提交
3923
{
3924
	struct rlimit *old_rlim = p->signal->rlim + resource;
L
Linus Torvalds 已提交
3925 3926 3927 3928

	/* Control the ability to change the hard limit (whether
	   lowering or raising it), so that the hard limit can
	   later be used as a safe reset point for the soft limit
D
David Howells 已提交
3929
	   upon context transitions.  See selinux_bprm_committing_creds. */
L
Linus Torvalds 已提交
3930
	if (old_rlim->rlim_max != new_rlim->rlim_max)
3931 3932
		return avc_has_perm(current_sid(), task_sid(p),
				    SECCLASS_PROCESS, PROCESS__SETRLIMIT, NULL);
L
Linus Torvalds 已提交
3933 3934 3935 3936

	return 0;
}

3937
static int selinux_task_setscheduler(struct task_struct *p)
L
Linus Torvalds 已提交
3938
{
3939 3940
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETSCHED, NULL);
L
Linus Torvalds 已提交
3941 3942 3943 3944
}

static int selinux_task_getscheduler(struct task_struct *p)
{
3945 3946
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__GETSCHED, NULL);
L
Linus Torvalds 已提交
3947 3948
}

3949 3950
static int selinux_task_movememory(struct task_struct *p)
{
3951 3952
	return avc_has_perm(current_sid(), task_sid(p), SECCLASS_PROCESS,
			    PROCESS__SETSCHED, NULL);
3953 3954
}

3955 3956
static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
				int sig, u32 secid)
L
Linus Torvalds 已提交
3957 3958 3959 3960 3961 3962 3963
{
	u32 perm;

	if (!sig)
		perm = PROCESS__SIGNULL; /* null signal; existence test */
	else
		perm = signal_to_av(sig);
3964 3965 3966
	if (!secid)
		secid = current_sid();
	return avc_has_perm(secid, task_sid(p), SECCLASS_PROCESS, perm, NULL);
L
Linus Torvalds 已提交
3967 3968 3969 3970 3971 3972
}

static void selinux_task_to_inode(struct task_struct *p,
				  struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
3973
	u32 sid = task_sid(p);
L
Linus Torvalds 已提交
3974

3975
	spin_lock(&isec->lock);
3976
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
3977
	isec->sid = sid;
3978
	isec->initialized = LABEL_INITIALIZED;
3979
	spin_unlock(&isec->lock);
L
Linus Torvalds 已提交
3980 3981 3982
}

/* Returns error only if unable to parse addresses */
3983
static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3984
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
3985 3986 3987 3988
{
	int offset, ihlen, ret = -EINVAL;
	struct iphdr _iph, *ih;

3989
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
3990 3991 3992 3993 3994 3995 3996 3997
	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
	if (ih == NULL)
		goto out;

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

3998 3999
	ad->u.net->v4info.saddr = ih->saddr;
	ad->u.net->v4info.daddr = ih->daddr;
L
Linus Torvalds 已提交
4000 4001
	ret = 0;

4002 4003 4004
	if (proto)
		*proto = ih->protocol;

L
Linus Torvalds 已提交
4005
	switch (ih->protocol) {
4006 4007
	case IPPROTO_TCP: {
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
4008

4009 4010
		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;
L
Linus Torvalds 已提交
4011 4012 4013 4014 4015 4016

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

4017 4018
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
4019
		break;
4020 4021 4022 4023 4024 4025 4026 4027
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

L
Linus Torvalds 已提交
4028
		offset += ihlen;
4029
		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
L
Linus Torvalds 已提交
4030
		if (uh == NULL)
4031
			break;
L
Linus Torvalds 已提交
4032

4033 4034
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
4035 4036
		break;
	}
L
Linus Torvalds 已提交
4037

J
James Morris 已提交
4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048
	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;

4049 4050
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
4051
		break;
4052
	}
J
James Morris 已提交
4053

4054 4055 4056
	default:
		break;
	}
L
Linus Torvalds 已提交
4057 4058 4059 4060
out:
	return ret;
}

4061
#if IS_ENABLED(CONFIG_IPV6)
L
Linus Torvalds 已提交
4062 4063

/* Returns error only if unable to parse addresses */
4064
static int selinux_parse_skb_ipv6(struct sk_buff *skb,
4065
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
4066 4067 4068 4069
{
	u8 nexthdr;
	int ret = -EINVAL, offset;
	struct ipv6hdr _ipv6h, *ip6;
4070
	__be16 frag_off;
L
Linus Torvalds 已提交
4071

4072
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
4073 4074 4075 4076
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		goto out;

4077 4078
	ad->u.net->v6info.saddr = ip6->saddr;
	ad->u.net->v6info.daddr = ip6->daddr;
L
Linus Torvalds 已提交
4079 4080 4081 4082
	ret = 0;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
4083
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
L
Linus Torvalds 已提交
4084 4085 4086
	if (offset < 0)
		goto out;

4087 4088 4089
	if (proto)
		*proto = nexthdr;

L
Linus Torvalds 已提交
4090 4091
	switch (nexthdr) {
	case IPPROTO_TCP: {
4092
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
4093 4094 4095 4096 4097

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

4098 4099
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
4100 4101 4102 4103 4104 4105 4106 4107 4108 4109
		break;
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

4110 4111
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
L
Linus Torvalds 已提交
4112 4113 4114
		break;
	}

J
James Morris 已提交
4115 4116 4117 4118 4119 4120 4121
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

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

4122 4123
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
4124
		break;
4125
	}
J
James Morris 已提交
4126

L
Linus Torvalds 已提交
4127 4128 4129 4130 4131 4132 4133 4134 4135 4136
	/* includes fragments */
	default:
		break;
	}
out:
	return ret;
}

#endif /* IPV6 */

4137
static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
4138
			     char **_addrp, int src, u8 *proto)
L
Linus Torvalds 已提交
4139
{
4140 4141
	char *addrp;
	int ret;
L
Linus Torvalds 已提交
4142

4143
	switch (ad->u.net->family) {
L
Linus Torvalds 已提交
4144
	case PF_INET:
4145
		ret = selinux_parse_skb_ipv4(skb, ad, proto);
4146 4147
		if (ret)
			goto parse_error;
4148 4149
		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
				       &ad->u.net->v4info.daddr);
4150
		goto okay;
L
Linus Torvalds 已提交
4151

4152
#if IS_ENABLED(CONFIG_IPV6)
L
Linus Torvalds 已提交
4153
	case PF_INET6:
4154
		ret = selinux_parse_skb_ipv6(skb, ad, proto);
4155 4156
		if (ret)
			goto parse_error;
4157 4158
		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
				       &ad->u.net->v6info.daddr);
4159
		goto okay;
L
Linus Torvalds 已提交
4160 4161
#endif	/* IPV6 */
	default:
4162 4163
		addrp = NULL;
		goto okay;
L
Linus Torvalds 已提交
4164 4165
	}

4166 4167 4168 4169
parse_error:
	printk(KERN_WARNING
	       "SELinux: failure in selinux_parse_skb(),"
	       " unable to parse packet\n");
L
Linus Torvalds 已提交
4170
	return ret;
4171 4172 4173 4174 4175

okay:
	if (_addrp)
		*_addrp = addrp;
	return 0;
L
Linus Torvalds 已提交
4176 4177
}

4178
/**
4179
 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
4180
 * @skb: the packet
4181
 * @family: protocol family
4182
 * @sid: the packet's peer label SID
4183 4184
 *
 * Description:
4185 4186 4187 4188 4189 4190
 * Check the various different forms of network peer labeling and determine
 * the peer label/SID for the packet; most of the magic actually occurs in
 * the security server function security_net_peersid_cmp().  The function
 * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
 * or -EACCES if @sid is invalid due to inconsistencies with the different
 * peer labels.
4191 4192
 *
 */
4193
static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
4194
{
4195
	int err;
4196 4197
	u32 xfrm_sid;
	u32 nlbl_sid;
4198
	u32 nlbl_type;
4199

4200
	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
4201 4202 4203 4204 4205
	if (unlikely(err))
		return -EACCES;
	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
	if (unlikely(err))
		return -EACCES;
4206

4207 4208 4209 4210 4211
	err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
	if (unlikely(err)) {
		printk(KERN_WARNING
		       "SELinux: failure in selinux_skb_peerlbl_sid(),"
		       " unable to determine packet's peer label\n");
4212
		return -EACCES;
4213
	}
4214 4215

	return 0;
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
/**
 * selinux_conn_sid - Determine the child socket label for a connection
 * @sk_sid: the parent socket's SID
 * @skb_sid: the packet's SID
 * @conn_sid: the resulting connection SID
 *
 * If @skb_sid is valid then the user:role:type information from @sk_sid is
 * combined with the MLS information from @skb_sid in order to create
 * @conn_sid.  If @skb_sid is not valid then then @conn_sid is simply a copy
 * of @sk_sid.  Returns zero on success, negative values on failure.
 *
 */
static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)
{
	int err = 0;

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

	return err;
}

L
Linus Torvalds 已提交
4242
/* socket security operations */
4243

4244 4245
static int socket_sockcreate_sid(const struct task_security_struct *tsec,
				 u16 secclass, u32 *socksid)
4246
{
4247 4248 4249 4250 4251 4252 4253
	if (tsec->sockcreate_sid > SECSID_NULL) {
		*socksid = tsec->sockcreate_sid;
		return 0;
	}

	return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
				       socksid);
4254 4255
}

4256
static int sock_has_perm(struct sock *sk, u32 perms)
L
Linus Torvalds 已提交
4257
{
4258
	struct sk_security_struct *sksec = sk->sk_security;
4259
	struct common_audit_data ad;
4260
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4261

4262 4263
	if (sksec->sid == SECINITSID_KERNEL)
		return 0;
L
Linus Torvalds 已提交
4264

4265
	ad.type = LSM_AUDIT_DATA_NET;
4266 4267
	ad.u.net = &net;
	ad.u.net->sk = sk;
L
Linus Torvalds 已提交
4268

4269 4270
	return avc_has_perm(current_sid(), sksec->sid, sksec->sclass, perms,
			    &ad);
L
Linus Torvalds 已提交
4271 4272 4273 4274 4275
}

static int selinux_socket_create(int family, int type,
				 int protocol, int kern)
{
4276
	const struct task_security_struct *tsec = current_security();
4277
	u32 newsid;
4278
	u16 secclass;
4279
	int rc;
L
Linus Torvalds 已提交
4280 4281

	if (kern)
4282
		return 0;
4283 4284

	secclass = socket_type_to_security_class(family, type, protocol);
4285 4286 4287 4288
	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
	if (rc)
		return rc;

4289
	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
L
Linus Torvalds 已提交
4290 4291
}

V
Venkat Yekkirala 已提交
4292 4293
static int selinux_socket_post_create(struct socket *sock, int family,
				      int type, int protocol, int kern)
L
Linus Torvalds 已提交
4294
{
4295
	const struct task_security_struct *tsec = current_security();
4296
	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
4297
	struct sk_security_struct *sksec;
4298 4299
	u16 sclass = socket_type_to_security_class(family, type, protocol);
	u32 sid = SECINITSID_KERNEL;
4300 4301
	int err = 0;

4302 4303
	if (!kern) {
		err = socket_sockcreate_sid(tsec, sclass, &sid);
4304 4305 4306
		if (err)
			return err;
	}
4307

4308 4309
	isec->sclass = sclass;
	isec->sid = sid;
4310
	isec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
4311

4312 4313
	if (sock->sk) {
		sksec = sock->sk->sk_security;
4314 4315
		sksec->sclass = sclass;
		sksec->sid = sid;
4316
		err = selinux_netlbl_socket_post_create(sock->sk, family);
4317 4318
	}

V
Venkat Yekkirala 已提交
4319
	return err;
L
Linus Torvalds 已提交
4320 4321 4322 4323 4324 4325 4326 4327
}

/* 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)
{
4328
	struct sock *sk = sock->sk;
L
Linus Torvalds 已提交
4329 4330 4331
	u16 family;
	int err;

4332
	err = sock_has_perm(sk, SOCKET__BIND);
L
Linus Torvalds 已提交
4333 4334 4335 4336 4337
	if (err)
		goto out;

	/*
	 * If PF_INET or PF_INET6, check name_bind permission for the port.
4338 4339
	 * Multiple address binding for SCTP is not supported yet: we just
	 * check the first address now.
L
Linus Torvalds 已提交
4340
	 */
4341
	family = sk->sk_family;
L
Linus Torvalds 已提交
4342 4343
	if (family == PF_INET || family == PF_INET6) {
		char *addrp;
4344
		struct sk_security_struct *sksec = sk->sk_security;
4345
		struct common_audit_data ad;
4346
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4347 4348 4349
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
4350
		u32 sid, node_perm;
L
Linus Torvalds 已提交
4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361

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

4362 4363 4364
		if (snum) {
			int low, high;

4365
			inet_get_local_port_range(sock_net(sk), &low, &high);
4366

4367 4368
			if (snum < max(inet_prot_sock(sock_net(sk)), low) ||
			    snum > high) {
P
Paul Moore 已提交
4369 4370
				err = sel_netport_sid(sk->sk_protocol,
						      snum, &sid);
4371 4372
				if (err)
					goto out;
4373
				ad.type = LSM_AUDIT_DATA_NET;
4374 4375 4376
				ad.u.net = &net;
				ad.u.net->sport = htons(snum);
				ad.u.net->family = family;
4377 4378
				err = avc_has_perm(sksec->sid, sid,
						   sksec->sclass,
4379 4380 4381 4382
						   SOCKET__NAME_BIND, &ad);
				if (err)
					goto out;
			}
L
Linus Torvalds 已提交
4383
		}
4384

4385
		switch (sksec->sclass) {
4386
		case SECCLASS_TCP_SOCKET:
L
Linus Torvalds 已提交
4387 4388
			node_perm = TCP_SOCKET__NODE_BIND;
			break;
4389

4390
		case SECCLASS_UDP_SOCKET:
L
Linus Torvalds 已提交
4391 4392
			node_perm = UDP_SOCKET__NODE_BIND;
			break;
J
James Morris 已提交
4393 4394 4395 4396 4397

		case SECCLASS_DCCP_SOCKET:
			node_perm = DCCP_SOCKET__NODE_BIND;
			break;

L
Linus Torvalds 已提交
4398 4399 4400 4401
		default:
			node_perm = RAWIP_SOCKET__NODE_BIND;
			break;
		}
4402

4403
		err = sel_netnode_sid(addrp, family, &sid);
L
Linus Torvalds 已提交
4404 4405
		if (err)
			goto out;
4406

4407
		ad.type = LSM_AUDIT_DATA_NET;
4408 4409 4410
		ad.u.net = &net;
		ad.u.net->sport = htons(snum);
		ad.u.net->family = family;
L
Linus Torvalds 已提交
4411 4412

		if (family == PF_INET)
4413
			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
L
Linus Torvalds 已提交
4414
		else
4415
			ad.u.net->v6info.saddr = addr6->sin6_addr;
L
Linus Torvalds 已提交
4416

4417 4418
		err = avc_has_perm(sksec->sid, sid,
				   sksec->sclass, node_perm, &ad);
L
Linus Torvalds 已提交
4419 4420 4421 4422 4423 4424 4425 4426 4427
		if (err)
			goto out;
	}
out:
	return err;
}

static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
{
4428
	struct sock *sk = sock->sk;
4429
	struct sk_security_struct *sksec = sk->sk_security;
L
Linus Torvalds 已提交
4430 4431
	int err;

4432
	err = sock_has_perm(sk, SOCKET__CONNECT);
L
Linus Torvalds 已提交
4433 4434 4435 4436
	if (err)
		return err;

	/*
J
James Morris 已提交
4437
	 * If a TCP or DCCP socket, check name_connect permission for the port.
L
Linus Torvalds 已提交
4438
	 */
4439 4440
	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
4441
		struct common_audit_data ad;
4442
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4443 4444 4445
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
J
James Morris 已提交
4446
		u32 sid, perm;
L
Linus Torvalds 已提交
4447 4448 4449

		if (sk->sk_family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
4450
			if (addrlen < sizeof(struct sockaddr_in))
L
Linus Torvalds 已提交
4451 4452 4453 4454
				return -EINVAL;
			snum = ntohs(addr4->sin_port);
		} else {
			addr6 = (struct sockaddr_in6 *)address;
4455
			if (addrlen < SIN6_LEN_RFC2133)
L
Linus Torvalds 已提交
4456 4457 4458 4459
				return -EINVAL;
			snum = ntohs(addr6->sin6_port);
		}

P
Paul Moore 已提交
4460
		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
L
Linus Torvalds 已提交
4461 4462 4463
		if (err)
			goto out;

4464
		perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
J
James Morris 已提交
4465 4466
		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;

4467
		ad.type = LSM_AUDIT_DATA_NET;
4468 4469 4470
		ad.u.net = &net;
		ad.u.net->dport = htons(snum);
		ad.u.net->family = sk->sk_family;
4471
		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
L
Linus Torvalds 已提交
4472 4473 4474 4475
		if (err)
			goto out;
	}

4476 4477
	err = selinux_netlbl_socket_connect(sk, address);

L
Linus Torvalds 已提交
4478 4479 4480 4481 4482 4483
out:
	return err;
}

static int selinux_socket_listen(struct socket *sock, int backlog)
{
4484
	return sock_has_perm(sock->sk, SOCKET__LISTEN);
L
Linus Torvalds 已提交
4485 4486 4487 4488 4489 4490 4491
}

static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
{
	int err;
	struct inode_security_struct *isec;
	struct inode_security_struct *newisec;
4492 4493
	u16 sclass;
	u32 sid;
L
Linus Torvalds 已提交
4494

4495
	err = sock_has_perm(sock->sk, SOCKET__ACCEPT);
L
Linus Torvalds 已提交
4496 4497 4498
	if (err)
		return err;

4499
	isec = inode_security_novalidate(SOCK_INODE(sock));
4500 4501 4502 4503 4504 4505 4506 4507
	spin_lock(&isec->lock);
	sclass = isec->sclass;
	sid = isec->sid;
	spin_unlock(&isec->lock);

	newisec = inode_security_novalidate(SOCK_INODE(newsock));
	newisec->sclass = sclass;
	newisec->sid = sid;
4508
	newisec->initialized = LABEL_INITIALIZED;
L
Linus Torvalds 已提交
4509 4510 4511 4512 4513

	return 0;
}

static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4514
				  int size)
L
Linus Torvalds 已提交
4515
{
4516
	return sock_has_perm(sock->sk, SOCKET__WRITE);
L
Linus Torvalds 已提交
4517 4518 4519 4520 4521
}

static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
				  int size, int flags)
{
4522
	return sock_has_perm(sock->sk, SOCKET__READ);
L
Linus Torvalds 已提交
4523 4524 4525 4526
}

static int selinux_socket_getsockname(struct socket *sock)
{
4527
	return sock_has_perm(sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4528 4529 4530 4531
}

static int selinux_socket_getpeername(struct socket *sock)
{
4532
	return sock_has_perm(sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4533 4534
}

4535
static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
L
Linus Torvalds 已提交
4536
{
4537 4538
	int err;

4539
	err = sock_has_perm(sock->sk, SOCKET__SETOPT);
4540 4541 4542 4543
	if (err)
		return err;

	return selinux_netlbl_socket_setsockopt(sock, level, optname);
L
Linus Torvalds 已提交
4544 4545 4546 4547 4548
}

static int selinux_socket_getsockopt(struct socket *sock, int level,
				     int optname)
{
4549
	return sock_has_perm(sock->sk, SOCKET__GETOPT);
L
Linus Torvalds 已提交
4550 4551 4552 4553
}

static int selinux_socket_shutdown(struct socket *sock, int how)
{
4554
	return sock_has_perm(sock->sk, SOCKET__SHUTDOWN);
L
Linus Torvalds 已提交
4555 4556
}

4557 4558
static int selinux_socket_unix_stream_connect(struct sock *sock,
					      struct sock *other,
L
Linus Torvalds 已提交
4559 4560
					      struct sock *newsk)
{
4561 4562
	struct sk_security_struct *sksec_sock = sock->sk_security;
	struct sk_security_struct *sksec_other = other->sk_security;
4563
	struct sk_security_struct *sksec_new = newsk->sk_security;
4564
	struct common_audit_data ad;
4565
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4566 4567
	int err;

4568
	ad.type = LSM_AUDIT_DATA_NET;
4569 4570
	ad.u.net = &net;
	ad.u.net->sk = other;
L
Linus Torvalds 已提交
4571

4572 4573
	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
			   sksec_other->sclass,
L
Linus Torvalds 已提交
4574 4575 4576 4577 4578
			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
	if (err)
		return err;

	/* server child socket */
4579 4580 4581 4582 4583
	sksec_new->peer_sid = sksec_sock->sid;
	err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
				    &sksec_new->sid);
	if (err)
		return err;
4584

4585 4586 4587 4588
	/* connecting socket */
	sksec_sock->peer_sid = sksec_new->sid;

	return 0;
L
Linus Torvalds 已提交
4589 4590 4591 4592 4593
}

static int selinux_socket_unix_may_send(struct socket *sock,
					struct socket *other)
{
4594 4595
	struct sk_security_struct *ssec = sock->sk->sk_security;
	struct sk_security_struct *osec = other->sk->sk_security;
4596
	struct common_audit_data ad;
4597
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4598

4599
	ad.type = LSM_AUDIT_DATA_NET;
4600 4601
	ad.u.net = &net;
	ad.u.net->sk = other->sk;
L
Linus Torvalds 已提交
4602

4603 4604
	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
			    &ad);
L
Linus Torvalds 已提交
4605 4606
}

4607 4608
static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
				    char *addrp, u16 family, u32 peer_sid,
4609
				    struct common_audit_data *ad)
4610 4611 4612 4613 4614
{
	int err;
	u32 if_sid;
	u32 node_sid;

4615
	err = sel_netif_sid(ns, ifindex, &if_sid);
4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629
	if (err)
		return err;
	err = avc_has_perm(peer_sid, if_sid,
			   SECCLASS_NETIF, NETIF__INGRESS, ad);
	if (err)
		return err;

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

4630
static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4631
				       u16 family)
4632
{
4633
	int err = 0;
4634 4635
	struct sk_security_struct *sksec = sk->sk_security;
	u32 sk_sid = sksec->sid;
4636
	struct common_audit_data ad;
4637
	struct lsm_network_audit net = {0,};
4638 4639
	char *addrp;

4640
	ad.type = LSM_AUDIT_DATA_NET;
4641 4642 4643
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4644 4645 4646
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
	if (err)
		return err;
L
Linus Torvalds 已提交
4647

4648
	if (selinux_secmark_enabled()) {
4649
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4650
				   PACKET__RECV, &ad);
4651 4652 4653
		if (err)
			return err;
	}
4654

4655 4656 4657 4658
	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
	if (err)
		return err;
	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4659

4660 4661 4662 4663 4664
	return err;
}

static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
4665
	int err;
4666
	struct sk_security_struct *sksec = sk->sk_security;
4667 4668
	u16 family = sk->sk_family;
	u32 sk_sid = sksec->sid;
4669
	struct common_audit_data ad;
4670
	struct lsm_network_audit net = {0,};
4671
	char *addrp;
4672 4673
	u8 secmark_active;
	u8 peerlbl_active;
4674 4675

	if (family != PF_INET && family != PF_INET6)
4676
		return 0;
4677 4678

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
A
Al Viro 已提交
4679
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4680 4681
		family = PF_INET;

4682 4683 4684 4685
	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_sock_rcv_skb_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
4686
	if (!selinux_policycap_netpeer)
4687 4688 4689
		return selinux_sock_rcv_skb_compat(sk, skb, family);

	secmark_active = selinux_secmark_enabled();
4690
	peerlbl_active = selinux_peerlbl_enabled();
4691 4692 4693
	if (!secmark_active && !peerlbl_active)
		return 0;

4694
	ad.type = LSM_AUDIT_DATA_NET;
4695 4696 4697
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4698
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4699
	if (err)
4700
		return err;
4701

4702
	if (peerlbl_active) {
4703 4704 4705
		u32 peer_sid;

		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4706 4707
		if (err)
			return err;
4708 4709
		err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
					       addrp, family, peer_sid, &ad);
4710
		if (err) {
4711
			selinux_netlbl_err(skb, family, err, 0);
4712
			return err;
4713
		}
4714 4715
		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
				   PEER__RECV, &ad);
C
Chad Hanson 已提交
4716
		if (err) {
4717
			selinux_netlbl_err(skb, family, err, 0);
C
Chad Hanson 已提交
4718 4719
			return err;
		}
4720 4721
	}

4722
	if (secmark_active) {
4723 4724 4725 4726 4727 4728
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
				   PACKET__RECV, &ad);
		if (err)
			return err;
	}

4729
	return err;
L
Linus Torvalds 已提交
4730 4731
}

C
Catherine Zhang 已提交
4732 4733
static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
					    int __user *optlen, unsigned len)
L
Linus Torvalds 已提交
4734 4735 4736 4737
{
	int err = 0;
	char *scontext;
	u32 scontext_len;
4738
	struct sk_security_struct *sksec = sock->sk->sk_security;
4739
	u32 peer_sid = SECSID_NULL;
L
Linus Torvalds 已提交
4740

4741 4742
	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
	    sksec->sclass == SECCLASS_TCP_SOCKET)
4743
		peer_sid = sksec->peer_sid;
4744 4745
	if (peer_sid == SECSID_NULL)
		return -ENOPROTOOPT;
L
Linus Torvalds 已提交
4746

C
Catherine Zhang 已提交
4747
	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
L
Linus Torvalds 已提交
4748
	if (err)
4749
		return err;
L
Linus Torvalds 已提交
4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760 4761 4762 4763 4764 4765

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

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

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

4766
static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
C
Catherine Zhang 已提交
4767
{
4768
	u32 peer_secid = SECSID_NULL;
4769
	u16 family;
4770
	struct inode_security_struct *isec;
C
Catherine Zhang 已提交
4771

4772 4773 4774 4775 4776
	if (skb && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;
	else if (skb && skb->protocol == htons(ETH_P_IPV6))
		family = PF_INET6;
	else if (sock)
4777 4778 4779 4780
		family = sock->sk->sk_family;
	else
		goto out;

4781 4782 4783 4784
	if (sock && family == PF_UNIX) {
		isec = inode_security_novalidate(SOCK_INODE(sock));
		peer_secid = isec->sid;
	} else if (skb)
4785
		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
C
Catherine Zhang 已提交
4786

4787
out:
4788
	*secid = peer_secid;
4789 4790 4791
	if (peer_secid == SECSID_NULL)
		return -EINVAL;
	return 0;
C
Catherine Zhang 已提交
4792 4793
}

A
Al Viro 已提交
4794
static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
L
Linus Torvalds 已提交
4795
{
4796 4797 4798 4799 4800 4801 4802 4803
	struct sk_security_struct *sksec;

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

	sksec->peer_sid = SECINITSID_UNLABELED;
	sksec->sid = SECINITSID_UNLABELED;
4804
	sksec->sclass = SECCLASS_SOCKET;
4805 4806 4807 4808
	selinux_netlbl_sk_security_reset(sksec);
	sk->sk_security = sksec;

	return 0;
L
Linus Torvalds 已提交
4809 4810 4811 4812
}

static void selinux_sk_free_security(struct sock *sk)
{
4813 4814 4815 4816 4817
	struct sk_security_struct *sksec = sk->sk_security;

	sk->sk_security = NULL;
	selinux_netlbl_sk_security_free(sksec);
	kfree(sksec);
L
Linus Torvalds 已提交
4818 4819
}

4820
static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4821
{
4822 4823
	struct sk_security_struct *sksec = sk->sk_security;
	struct sk_security_struct *newsksec = newsk->sk_security;
4824

4825 4826 4827
	newsksec->sid = sksec->sid;
	newsksec->peer_sid = sksec->peer_sid;
	newsksec->sclass = sksec->sclass;
4828

4829
	selinux_netlbl_sk_security_reset(newsksec);
4830 4831
}

V
Venkat Yekkirala 已提交
4832
static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4833
{
4834
	if (!sk)
V
Venkat Yekkirala 已提交
4835
		*secid = SECINITSID_ANY_SOCKET;
4836 4837
	else {
		struct sk_security_struct *sksec = sk->sk_security;
4838

V
Venkat Yekkirala 已提交
4839
		*secid = sksec->sid;
4840
	}
4841 4842
}

4843
static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4844
{
4845 4846
	struct inode_security_struct *isec =
		inode_security_novalidate(SOCK_INODE(parent));
4847 4848
	struct sk_security_struct *sksec = sk->sk_security;

4849 4850
	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
	    sk->sk_family == PF_UNIX)
4851
		isec->sid = sksec->sid;
4852
	sksec->sclass = isec->sclass;
4853 4854
}

4855 4856
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				     struct request_sock *req)
4857 4858 4859
{
	struct sk_security_struct *sksec = sk->sk_security;
	int err;
4860
	u16 family = req->rsk_ops->family;
4861
	u32 connsid;
4862 4863
	u32 peersid;

4864
	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4865 4866
	if (err)
		return err;
4867 4868 4869 4870 4871
	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
	if (err)
		return err;
	req->secid = connsid;
	req->peer_secid = peersid;
4872

4873
	return selinux_netlbl_inet_conn_request(req, family);
4874 4875
}

4876 4877
static void selinux_inet_csk_clone(struct sock *newsk,
				   const struct request_sock *req)
4878 4879 4880 4881
{
	struct sk_security_struct *newsksec = newsk->sk_security;

	newsksec->sid = req->secid;
4882
	newsksec->peer_sid = req->peer_secid;
4883 4884 4885 4886
	/* 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. */
4887

P
Paul Moore 已提交
4888 4889
	/* We don't need to take any sort of lock here as we are the only
	 * thread with access to newsksec */
4890
	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4891 4892
}

4893
static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4894
{
4895
	u16 family = sk->sk_family;
4896 4897
	struct sk_security_struct *sksec = sk->sk_security;

4898 4899 4900 4901 4902
	/* handle mapped IPv4 packets arriving via IPv6 sockets */
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
		family = PF_INET;

	selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4903 4904
}

4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917 4918 4919 4920 4921 4922 4923 4924 4925
static int selinux_secmark_relabel_packet(u32 sid)
{
	const struct task_security_struct *__tsec;
	u32 tsid;

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

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

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

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

4926 4927
static void selinux_req_classify_flow(const struct request_sock *req,
				      struct flowi *fl)
4928
{
4929
	fl->flowi_secid = req->secid;
4930 4931
}

4932 4933 4934 4935 4936 4937 4938 4939 4940 4941 4942 4943 4944 4945 4946 4947 4948 4949
static int selinux_tun_dev_alloc_security(void **security)
{
	struct tun_security_struct *tunsec;

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

	*security = tunsec;
	return 0;
}

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

4950 4951 4952 4953 4954 4955 4956 4957 4958 4959 4960 4961 4962 4963 4964
static int selinux_tun_dev_create(void)
{
	u32 sid = current_sid();

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

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

4965
static int selinux_tun_dev_attach_queue(void *security)
4966
{
4967 4968 4969 4970 4971 4972 4973 4974 4975
	struct tun_security_struct *tunsec = security;

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

static int selinux_tun_dev_attach(struct sock *sk, void *security)
{
	struct tun_security_struct *tunsec = security;
4976 4977 4978 4979 4980 4981 4982 4983 4984
	struct sk_security_struct *sksec = sk->sk_security;

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

4985
	sksec->sid = tunsec->sid;
4986
	sksec->sclass = SECCLASS_TUN_SOCKET;
4987 4988

	return 0;
4989 4990
}

4991
static int selinux_tun_dev_open(void *security)
4992
{
4993
	struct tun_security_struct *tunsec = security;
4994 4995 4996
	u32 sid = current_sid();
	int err;

4997
	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
4998 4999 5000 5001 5002 5003 5004
			   TUN_SOCKET__RELABELFROM, NULL);
	if (err)
		return err;
	err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
			   TUN_SOCKET__RELABELTO, NULL);
	if (err)
		return err;
5005
	tunsec->sid = sid;
5006 5007 5008 5009

	return 0;
}

L
Linus Torvalds 已提交
5010 5011 5012 5013 5014
static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
{
	int err = 0;
	u32 perm;
	struct nlmsghdr *nlh;
5015
	struct sk_security_struct *sksec = sk->sk_security;
5016

5017
	if (skb->len < NLMSG_HDRLEN) {
L
Linus Torvalds 已提交
5018 5019 5020
		err = -EINVAL;
		goto out;
	}
5021
	nlh = nlmsg_hdr(skb);
5022

5023
	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
L
Linus Torvalds 已提交
5024 5025
	if (err) {
		if (err == -EINVAL) {
5026 5027 5028
			pr_warn_ratelimited("SELinux: unrecognized netlink"
			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
			       " pig=%d comm=%s\n",
5029
			       sk->sk_protocol, nlh->nlmsg_type,
5030 5031
			       secclass_map[sksec->sclass - 1].name,
			       task_pid_nr(current), current->comm);
5032
			if (!selinux_enforcing || security_get_allow_unknown())
L
Linus Torvalds 已提交
5033 5034 5035 5036 5037 5038 5039 5040 5041
				err = 0;
		}

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

5042
	err = sock_has_perm(sk, perm);
L
Linus Torvalds 已提交
5043 5044 5045 5046 5047 5048
out:
	return err;
}

#ifdef CONFIG_NETFILTER

5049 5050
static unsigned int selinux_ip_forward(struct sk_buff *skb,
				       const struct net_device *indev,
5051
				       u16 family)
L
Linus Torvalds 已提交
5052
{
5053
	int err;
5054 5055
	char *addrp;
	u32 peer_sid;
5056
	struct common_audit_data ad;
5057
	struct lsm_network_audit net = {0,};
5058
	u8 secmark_active;
5059
	u8 netlbl_active;
5060
	u8 peerlbl_active;
5061

5062 5063
	if (!selinux_policycap_netpeer)
		return NF_ACCEPT;
5064

5065
	secmark_active = selinux_secmark_enabled();
5066
	netlbl_active = netlbl_enabled();
5067
	peerlbl_active = selinux_peerlbl_enabled();
5068 5069
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;
5070

5071 5072 5073
	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
		return NF_DROP;

5074
	ad.type = LSM_AUDIT_DATA_NET;
5075
	ad.u.net = &net;
5076
	ad.u.net->netif = indev->ifindex;
5077
	ad.u.net->family = family;
5078 5079 5080
	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
		return NF_DROP;

5081
	if (peerlbl_active) {
5082 5083
		err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
					       addrp, family, peer_sid, &ad);
5084
		if (err) {
5085
			selinux_netlbl_err(skb, family, err, 1);
5086
			return NF_DROP;
5087 5088
		}
	}
5089 5090 5091 5092 5093 5094

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

5095 5096 5097 5098 5099 5100 5101 5102
	if (netlbl_active)
		/* we do this in the FORWARD path and not the POST_ROUTING
		 * path because we want to make sure we apply the necessary
		 * labeling before IPsec is applied so we can leverage AH
		 * protection */
		if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
			return NF_DROP;

5103 5104 5105
	return NF_ACCEPT;
}

5106
static unsigned int selinux_ipv4_forward(void *priv,
5107
					 struct sk_buff *skb,
5108
					 const struct nf_hook_state *state)
5109
{
5110
	return selinux_ip_forward(skb, state->in, PF_INET);
5111 5112
}

5113
#if IS_ENABLED(CONFIG_IPV6)
5114
static unsigned int selinux_ipv6_forward(void *priv,
5115
					 struct sk_buff *skb,
5116
					 const struct nf_hook_state *state)
5117
{
5118
	return selinux_ip_forward(skb, state->in, PF_INET6);
5119 5120 5121
}
#endif	/* IPV6 */

5122 5123 5124
static unsigned int selinux_ip_output(struct sk_buff *skb,
				      u16 family)
{
5125
	struct sock *sk;
5126 5127 5128 5129 5130 5131 5132 5133
	u32 sid;

	if (!netlbl_enabled())
		return NF_ACCEPT;

	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path
	 * because we want to make sure we apply the necessary labeling
	 * before IPsec is applied so we can leverage AH protection */
5134 5135 5136 5137
	sk = skb->sk;
	if (sk) {
		struct sk_security_struct *sksec;

5138
		if (sk_listener(sk))
5139 5140 5141 5142 5143 5144 5145 5146 5147 5148 5149 5150 5151 5152 5153 5154
			/* if the socket is the listening state then this
			 * packet is a SYN-ACK packet which means it needs to
			 * be labeled based on the connection/request_sock and
			 * not the parent socket.  unfortunately, we can't
			 * lookup the request_sock yet as it isn't queued on
			 * the parent socket until after the SYN-ACK is sent.
			 * the "solution" is to simply pass the packet as-is
			 * as any IP option based labeling should be copied
			 * from the initial connection request (in the IP
			 * layer).  it is far from ideal, but until we get a
			 * security label in the packet itself this is the
			 * best we can do. */
			return NF_ACCEPT;

		/* standard practice, label using the parent socket */
		sksec = sk->sk_security;
5155 5156 5157 5158 5159 5160 5161 5162 5163
		sid = sksec->sid;
	} else
		sid = SECINITSID_KERNEL;
	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
		return NF_DROP;

	return NF_ACCEPT;
}

5164
static unsigned int selinux_ipv4_output(void *priv,
5165
					struct sk_buff *skb,
5166
					const struct nf_hook_state *state)
5167 5168 5169 5170
{
	return selinux_ip_output(skb, PF_INET);
}

5171
#if IS_ENABLED(CONFIG_IPV6)
5172 5173 5174 5175 5176 5177 5178 5179
static unsigned int selinux_ipv6_output(void *priv,
					struct sk_buff *skb,
					const struct nf_hook_state *state)
{
	return selinux_ip_output(skb, PF_INET6);
}
#endif	/* IPV6 */

5180 5181
static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
						int ifindex,
5182
						u16 family)
5183
{
5184
	struct sock *sk = skb_to_full_sk(skb);
5185
	struct sk_security_struct *sksec;
5186
	struct common_audit_data ad;
5187
	struct lsm_network_audit net = {0,};
5188 5189
	char *addrp;
	u8 proto;
L
Linus Torvalds 已提交
5190

5191 5192 5193 5194
	if (sk == NULL)
		return NF_ACCEPT;
	sksec = sk->sk_security;

5195
	ad.type = LSM_AUDIT_DATA_NET;
5196 5197 5198
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
5199 5200 5201
	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
		return NF_DROP;

5202
	if (selinux_secmark_enabled())
5203
		if (avc_has_perm(sksec->sid, skb->secmark,
5204
				 SECCLASS_PACKET, PACKET__SEND, &ad))
5205
			return NF_DROP_ERR(-ECONNREFUSED);
5206

5207 5208
	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
		return NF_DROP_ERR(-ECONNREFUSED);
5209 5210

	return NF_ACCEPT;
5211 5212
}

5213 5214
static unsigned int selinux_ip_postroute(struct sk_buff *skb,
					 const struct net_device *outdev,
5215
					 u16 family)
5216
{
5217 5218
	u32 secmark_perm;
	u32 peer_sid;
5219
	int ifindex = outdev->ifindex;
5220
	struct sock *sk;
5221
	struct common_audit_data ad;
5222
	struct lsm_network_audit net = {0,};
5223 5224 5225
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;
5226

5227 5228 5229 5230
	/* If any sort of compatibility mode is enabled then handoff processing
	 * to the selinux_ip_postroute_compat() function to deal with the
	 * special handling.  We do this in an attempt to keep this function
	 * as fast and as clean as possible. */
5231
	if (!selinux_policycap_netpeer)
5232
		return selinux_ip_postroute_compat(skb, ifindex, family);
5233 5234 5235 5236 5237 5238

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

5239
	sk = skb_to_full_sk(skb);
5240

5241
#ifdef CONFIG_XFRM
5242 5243 5244 5245 5246
	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
	 * packet transformation so allow the packet to pass without any checks
	 * since we'll have another chance to perform access control checks
	 * when the packet is on it's final way out.
	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst
5247 5248 5249 5250 5251 5252 5253
	 *       is NULL, in this case go ahead and apply access control.
	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the
	 *       TCP listening state we cannot wait until the XFRM processing
	 *       is done as we will miss out on the SA label if we do;
	 *       unfortunately, this means more work, but it is only once per
	 *       connection. */
	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&
5254
	    !(sk && sk_listener(sk)))
5255
		return NF_ACCEPT;
5256
#endif
5257

5258
	if (sk == NULL) {
5259 5260 5261 5262
		/* Without an associated socket the packet is either coming
		 * from the kernel or it is being forwarded; check the packet
		 * to determine which and if the packet is being forwarded
		 * query the packet directly to determine the security label. */
5263 5264
		if (skb->skb_iif) {
			secmark_perm = PACKET__FORWARD_OUT;
5265
			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
5266
				return NF_DROP;
5267 5268
		} else {
			secmark_perm = PACKET__SEND;
5269
			peer_sid = SECINITSID_KERNEL;
5270
		}
5271
	} else if (sk_listener(sk)) {
5272 5273 5274 5275 5276 5277 5278 5279 5280 5281
		/* Locally generated packet but the associated socket is in the
		 * listening state which means this is a SYN-ACK packet.  In
		 * this particular case the correct security label is assigned
		 * to the connection/request_sock but unfortunately we can't
		 * query the request_sock as it isn't queued on the parent
		 * socket until after the SYN-ACK packet is sent; the only
		 * viable choice is to regenerate the label like we do in
		 * selinux_inet_conn_request().  See also selinux_ip_output()
		 * for similar problems. */
		u32 skb_sid;
5282 5283 5284
		struct sk_security_struct *sksec;

		sksec = sk->sk_security;
5285 5286
		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
			return NF_DROP;
5287 5288 5289 5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301
		/* At this point, if the returned skb peerlbl is SECSID_NULL
		 * and the packet has been through at least one XFRM
		 * transformation then we must be dealing with the "final"
		 * form of labeled IPsec packet; since we've already applied
		 * all of our access controls on this packet we can safely
		 * pass the packet. */
		if (skb_sid == SECSID_NULL) {
			switch (family) {
			case PF_INET:
				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
					return NF_ACCEPT;
				break;
			case PF_INET6:
				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
					return NF_ACCEPT;
5302
				break;
5303 5304 5305 5306
			default:
				return NF_DROP_ERR(-ECONNREFUSED);
			}
		}
5307 5308 5309
		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
			return NF_DROP;
		secmark_perm = PACKET__SEND;
5310
	} else {
5311 5312
		/* Locally generated packet, fetch the security label from the
		 * associated socket. */
5313 5314 5315 5316
		struct sk_security_struct *sksec = sk->sk_security;
		peer_sid = sksec->sid;
		secmark_perm = PACKET__SEND;
	}
5317

5318
	ad.type = LSM_AUDIT_DATA_NET;
5319 5320 5321
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
5322
	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
5323
		return NF_DROP;
5324

5325 5326 5327
	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, secmark_perm, &ad))
5328
			return NF_DROP_ERR(-ECONNREFUSED);
5329 5330 5331 5332 5333

	if (peerlbl_active) {
		u32 if_sid;
		u32 node_sid;

5334
		if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
5335
			return NF_DROP;
5336 5337
		if (avc_has_perm(peer_sid, if_sid,
				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
5338
			return NF_DROP_ERR(-ECONNREFUSED);
5339 5340

		if (sel_netnode_sid(addrp, family, &node_sid))
5341
			return NF_DROP;
5342 5343
		if (avc_has_perm(peer_sid, node_sid,
				 SECCLASS_NODE, NODE__SENDTO, &ad))
5344
			return NF_DROP_ERR(-ECONNREFUSED);
5345
	}
5346

5347
	return NF_ACCEPT;
L
Linus Torvalds 已提交
5348 5349
}

5350
static unsigned int selinux_ipv4_postroute(void *priv,
5351
					   struct sk_buff *skb,
5352
					   const struct nf_hook_state *state)
L
Linus Torvalds 已提交
5353
{
5354
	return selinux_ip_postroute(skb, state->out, PF_INET);
L
Linus Torvalds 已提交
5355 5356
}

5357
#if IS_ENABLED(CONFIG_IPV6)
5358
static unsigned int selinux_ipv6_postroute(void *priv,
5359
					   struct sk_buff *skb,
5360
					   const struct nf_hook_state *state)
L
Linus Torvalds 已提交
5361
{
5362
	return selinux_ip_postroute(skb, state->out, PF_INET6);
L
Linus Torvalds 已提交
5363 5364 5365 5366 5367 5368 5369
}
#endif	/* IPV6 */

#endif	/* CONFIG_NETFILTER */

static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
{
5370
	return selinux_nlmsg_perm(sk, skb);
L
Linus Torvalds 已提交
5371 5372
}

5373
static int ipc_alloc_security(struct kern_ipc_perm *perm,
L
Linus Torvalds 已提交
5374 5375 5376 5377
			      u16 sclass)
{
	struct ipc_security_struct *isec;

J
James Morris 已提交
5378
	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
5379 5380 5381 5382
	if (!isec)
		return -ENOMEM;

	isec->sclass = sclass;
5383
	isec->sid = current_sid();
L
Linus Torvalds 已提交
5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399
	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
5400
	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
5401 5402 5403 5404 5405 5406 5407 5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418
	if (!msec)
		return -ENOMEM;

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

	return 0;
}

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

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

static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
5419
			u32 perms)
L
Linus Torvalds 已提交
5420 5421
{
	struct ipc_security_struct *isec;
5422
	struct common_audit_data ad;
5423
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5424 5425 5426

	isec = ipc_perms->security;

5427
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5428 5429
	ad.u.ipc_id = ipc_perms->key;

5430
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
L
Linus Torvalds 已提交
5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446
}

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

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

/* message queue security operations */
static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
{
	struct ipc_security_struct *isec;
5447
	struct common_audit_data ad;
5448
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5449 5450
	int rc;

5451
	rc = ipc_alloc_security(&msq->q_perm, SECCLASS_MSGQ);
L
Linus Torvalds 已提交
5452 5453 5454 5455 5456
	if (rc)
		return rc;

	isec = msq->q_perm.security;

5457
	ad.type = LSM_AUDIT_DATA_IPC;
5458
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5459

5460
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5461 5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476
			  MSGQ__CREATE, &ad);
	if (rc) {
		ipc_free_security(&msq->q_perm);
		return rc;
	}
	return 0;
}

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

static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
{
	struct ipc_security_struct *isec;
5477
	struct common_audit_data ad;
5478
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5479 5480 5481

	isec = msq->q_perm.security;

5482
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5483 5484
	ad.u.ipc_id = msq->q_perm.key;

5485
	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5486 5487 5488 5489 5490 5491 5492 5493
			    MSGQ__ASSOCIATE, &ad);
}

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

5494
	switch (cmd) {
L
Linus Torvalds 已提交
5495 5496 5497
	case IPC_INFO:
	case MSG_INFO:
		/* No specific object, just general system-wide information. */
5498 5499
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
L
Linus Torvalds 已提交
5500 5501 5502 5503 5504 5505 5506 5507 5508 5509 5510 5511 5512 5513
	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;
	}

5514
	err = ipc_has_perm(&msq->q_perm, perms);
L
Linus Torvalds 已提交
5515 5516 5517 5518 5519 5520 5521
	return err;
}

static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
{
	struct ipc_security_struct *isec;
	struct msg_security_struct *msec;
5522
	struct common_audit_data ad;
5523
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536
	int rc;

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

	/*
	 * First time through, need to assign label to the message
	 */
	if (msec->sid == SECINITSID_UNLABELED) {
		/*
		 * Compute new sid based on current process and
		 * message queue this message will be stored in
		 */
5537
		rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5538
					     NULL, &msec->sid);
L
Linus Torvalds 已提交
5539 5540 5541 5542
		if (rc)
			return rc;
	}

5543
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5544 5545 5546
	ad.u.ipc_id = msq->q_perm.key;

	/* Can this process write to the queue? */
5547
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5548 5549 5550
			  MSGQ__WRITE, &ad);
	if (!rc)
		/* Can this process send the message */
5551 5552
		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
				  MSG__SEND, &ad);
L
Linus Torvalds 已提交
5553 5554
	if (!rc)
		/* Can the message be put in the queue? */
5555 5556
		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
				  MSGQ__ENQUEUE, &ad);
L
Linus Torvalds 已提交
5557 5558 5559 5560 5561 5562 5563 5564 5565 5566

	return rc;
}

static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
				    struct task_struct *target,
				    long type, int mode)
{
	struct ipc_security_struct *isec;
	struct msg_security_struct *msec;
5567
	struct common_audit_data ad;
5568
	u32 sid = task_sid(target);
L
Linus Torvalds 已提交
5569 5570 5571 5572 5573
	int rc;

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

5574
	ad.type = LSM_AUDIT_DATA_IPC;
5575
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5576

5577
	rc = avc_has_perm(sid, isec->sid,
L
Linus Torvalds 已提交
5578 5579
			  SECCLASS_MSGQ, MSGQ__READ, &ad);
	if (!rc)
5580
		rc = avc_has_perm(sid, msec->sid,
L
Linus Torvalds 已提交
5581 5582 5583 5584 5585 5586 5587 5588
				  SECCLASS_MSG, MSG__RECEIVE, &ad);
	return rc;
}

/* Shared Memory security operations */
static int selinux_shm_alloc_security(struct shmid_kernel *shp)
{
	struct ipc_security_struct *isec;
5589
	struct common_audit_data ad;
5590
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5591 5592
	int rc;

5593
	rc = ipc_alloc_security(&shp->shm_perm, SECCLASS_SHM);
L
Linus Torvalds 已提交
5594 5595 5596 5597 5598
	if (rc)
		return rc;

	isec = shp->shm_perm.security;

5599
	ad.type = LSM_AUDIT_DATA_IPC;
5600
	ad.u.ipc_id = shp->shm_perm.key;
L
Linus Torvalds 已提交
5601

5602
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618
			  SHM__CREATE, &ad);
	if (rc) {
		ipc_free_security(&shp->shm_perm);
		return rc;
	}
	return 0;
}

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

static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
{
	struct ipc_security_struct *isec;
5619
	struct common_audit_data ad;
5620
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5621 5622 5623

	isec = shp->shm_perm.security;

5624
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5625 5626
	ad.u.ipc_id = shp->shm_perm.key;

5627
	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5628 5629 5630 5631 5632 5633 5634 5635 5636
			    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;

5637
	switch (cmd) {
L
Linus Torvalds 已提交
5638 5639 5640
	case IPC_INFO:
	case SHM_INFO:
		/* No specific object, just general system-wide information. */
5641 5642
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
L
Linus Torvalds 已提交
5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660
	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;
	}

5661
	err = ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5662 5663 5664 5665 5666 5667 5668 5669 5670 5671 5672 5673 5674
	return err;
}

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

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

5675
	return ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5676 5677 5678 5679 5680 5681
}

/* Semaphore security operations */
static int selinux_sem_alloc_security(struct sem_array *sma)
{
	struct ipc_security_struct *isec;
5682
	struct common_audit_data ad;
5683
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5684 5685
	int rc;

5686
	rc = ipc_alloc_security(&sma->sem_perm, SECCLASS_SEM);
L
Linus Torvalds 已提交
5687 5688 5689 5690 5691
	if (rc)
		return rc;

	isec = sma->sem_perm.security;

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

5695
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5696 5697 5698 5699 5700 5701 5702 5703 5704 5705 5706 5707 5708 5709 5710 5711
			  SEM__CREATE, &ad);
	if (rc) {
		ipc_free_security(&sma->sem_perm);
		return rc;
	}
	return 0;
}

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

static int selinux_sem_associate(struct sem_array *sma, int semflg)
{
	struct ipc_security_struct *isec;
5712
	struct common_audit_data ad;
5713
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5714 5715 5716

	isec = sma->sem_perm.security;

5717
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5718 5719
	ad.u.ipc_id = sma->sem_perm.key;

5720
	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5721 5722 5723 5724 5725 5726 5727 5728 5729
			    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;

5730
	switch (cmd) {
L
Linus Torvalds 已提交
5731 5732 5733
	case IPC_INFO:
	case SEM_INFO:
		/* No specific object, just general system-wide information. */
5734 5735
		return avc_has_perm(current_sid(), SECINITSID_KERNEL,
				    SECCLASS_SYSTEM, SYSTEM__IPC_INFO, NULL);
L
Linus Torvalds 已提交
5736 5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762
	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;
	}

5763
	err = ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5764 5765 5766 5767 5768 5769 5770 5771 5772 5773 5774 5775 5776
	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;

5777
	return ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5778 5779 5780 5781 5782 5783 5784 5785 5786 5787 5788 5789 5790 5791 5792
}

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;

5793
	return ipc_has_perm(ipcp, av);
L
Linus Torvalds 已提交
5794 5795
}

5796 5797 5798 5799 5800 5801
static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
{
	struct ipc_security_struct *isec = ipcp->security;
	*secid = isec->sid;
}

5802
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
L
Linus Torvalds 已提交
5803 5804 5805 5806 5807 5808
{
	if (inode)
		inode_doinit_with_dentry(inode, dentry);
}

static int selinux_getprocattr(struct task_struct *p,
5809
			       char *name, char **value)
L
Linus Torvalds 已提交
5810
{
5811
	const struct task_security_struct *__tsec;
5812
	u32 sid;
L
Linus Torvalds 已提交
5813
	int error;
5814
	unsigned len;
L
Linus Torvalds 已提交
5815

5816 5817 5818
	rcu_read_lock();
	__tsec = __task_cred(p)->security;

L
Linus Torvalds 已提交
5819
	if (current != p) {
5820 5821
		error = avc_has_perm(current_sid(), __tsec->sid,
				     SECCLASS_PROCESS, PROCESS__GETATTR, NULL);
L
Linus Torvalds 已提交
5822
		if (error)
5823
			goto bad;
L
Linus Torvalds 已提交
5824 5825 5826
	}

	if (!strcmp(name, "current"))
5827
		sid = __tsec->sid;
L
Linus Torvalds 已提交
5828
	else if (!strcmp(name, "prev"))
5829
		sid = __tsec->osid;
L
Linus Torvalds 已提交
5830
	else if (!strcmp(name, "exec"))
5831
		sid = __tsec->exec_sid;
L
Linus Torvalds 已提交
5832
	else if (!strcmp(name, "fscreate"))
5833
		sid = __tsec->create_sid;
5834
	else if (!strcmp(name, "keycreate"))
5835
		sid = __tsec->keycreate_sid;
5836
	else if (!strcmp(name, "sockcreate"))
5837
		sid = __tsec->sockcreate_sid;
5838 5839 5840 5841
	else {
		error = -EINVAL;
		goto bad;
	}
5842
	rcu_read_unlock();
L
Linus Torvalds 已提交
5843 5844 5845 5846

	if (!sid)
		return 0;

5847 5848 5849 5850
	error = security_sid_to_context(sid, value, &len);
	if (error)
		return error;
	return len;
5851

5852
bad:
5853
	rcu_read_unlock();
5854
	return error;
L
Linus Torvalds 已提交
5855 5856
}

5857
static int selinux_setprocattr(const char *name, void *value, size_t size)
L
Linus Torvalds 已提交
5858 5859
{
	struct task_security_struct *tsec;
D
David Howells 已提交
5860
	struct cred *new;
5861
	u32 mysid = current_sid(), sid = 0, ptsid;
L
Linus Torvalds 已提交
5862 5863 5864 5865 5866 5867 5868
	int error;
	char *str = value;

	/*
	 * Basic control over ability to set these attributes at all.
	 */
	if (!strcmp(name, "exec"))
5869 5870
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETEXEC, NULL);
L
Linus Torvalds 已提交
5871
	else if (!strcmp(name, "fscreate"))
5872 5873
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETFSCREATE, NULL);
5874
	else if (!strcmp(name, "keycreate"))
5875 5876
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETKEYCREATE, NULL);
5877
	else if (!strcmp(name, "sockcreate"))
5878 5879
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETSOCKCREATE, NULL);
L
Linus Torvalds 已提交
5880
	else if (!strcmp(name, "current"))
5881 5882
		error = avc_has_perm(mysid, mysid, SECCLASS_PROCESS,
				     PROCESS__SETCURRENT, NULL);
L
Linus Torvalds 已提交
5883 5884 5885 5886 5887 5888
	else
		error = -EINVAL;
	if (error)
		return error;

	/* Obtain a SID for the context, if one was specified. */
5889
	if (size && str[0] && str[0] != '\n') {
L
Linus Torvalds 已提交
5890 5891 5892 5893
		if (str[size-1] == '\n') {
			str[size-1] = 0;
			size--;
		}
5894
		error = security_context_to_sid(value, size, &sid, GFP_KERNEL);
5895
		if (error == -EINVAL && !strcmp(name, "fscreate")) {
5896 5897 5898 5899 5900 5901 5902 5903 5904 5905 5906 5907 5908 5909 5910
			if (!capable(CAP_MAC_ADMIN)) {
				struct audit_buffer *ab;
				size_t audit_size;

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

5911
				return error;
5912
			}
5913 5914 5915
			error = security_context_to_sid_force(value, size,
							      &sid);
		}
L
Linus Torvalds 已提交
5916 5917 5918 5919
		if (error)
			return error;
	}

D
David Howells 已提交
5920 5921 5922 5923
	new = prepare_creds();
	if (!new)
		return -ENOMEM;

L
Linus Torvalds 已提交
5924 5925 5926
	/* Permission checking based on the specified context is
	   performed during the actual operation (execve,
	   open/mkdir/...), when we know the full context of the
D
David Howells 已提交
5927
	   operation.  See selinux_bprm_set_creds for the execve
L
Linus Torvalds 已提交
5928 5929
	   checks and may_create for the file creation checks. The
	   operation will then fail if the context is not permitted. */
D
David Howells 已提交
5930 5931
	tsec = new->security;
	if (!strcmp(name, "exec")) {
L
Linus Torvalds 已提交
5932
		tsec->exec_sid = sid;
D
David Howells 已提交
5933
	} else if (!strcmp(name, "fscreate")) {
L
Linus Torvalds 已提交
5934
		tsec->create_sid = sid;
D
David Howells 已提交
5935
	} else if (!strcmp(name, "keycreate")) {
5936 5937
		error = avc_has_perm(mysid, sid, SECCLASS_KEY, KEY__CREATE,
				     NULL);
5938
		if (error)
D
David Howells 已提交
5939
			goto abort_change;
5940
		tsec->keycreate_sid = sid;
D
David Howells 已提交
5941
	} else if (!strcmp(name, "sockcreate")) {
5942
		tsec->sockcreate_sid = sid;
D
David Howells 已提交
5943 5944
	} else if (!strcmp(name, "current")) {
		error = -EINVAL;
L
Linus Torvalds 已提交
5945
		if (sid == 0)
D
David Howells 已提交
5946 5947 5948 5949
			goto abort_change;

		/* Only allow single threaded processes to change context */
		error = -EPERM;
5950
		if (!current_is_single_threaded()) {
D
David Howells 已提交
5951 5952 5953
			error = security_bounded_transition(tsec->sid, sid);
			if (error)
				goto abort_change;
5954
		}
L
Linus Torvalds 已提交
5955 5956 5957

		/* Check permissions for the transition. */
		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5958
				     PROCESS__DYNTRANSITION, NULL);
L
Linus Torvalds 已提交
5959
		if (error)
D
David Howells 已提交
5960
			goto abort_change;
L
Linus Torvalds 已提交
5961 5962 5963

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and fail. */
5964
		ptsid = ptrace_parent_sid();
5965
		if (ptsid != 0) {
D
David Howells 已提交
5966 5967
			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
					     PROCESS__PTRACE, NULL);
L
Linus Torvalds 已提交
5968
			if (error)
D
David Howells 已提交
5969
				goto abort_change;
L
Linus Torvalds 已提交
5970 5971
		}

D
David Howells 已提交
5972 5973 5974 5975 5976 5977 5978
		tsec->sid = sid;
	} else {
		error = -EINVAL;
		goto abort_change;
	}

	commit_creds(new);
L
Linus Torvalds 已提交
5979
	return size;
D
David Howells 已提交
5980 5981 5982 5983

abort_change:
	abort_creds(new);
	return error;
L
Linus Torvalds 已提交
5984 5985
}

5986 5987 5988 5989 5990
static int selinux_ismaclabel(const char *name)
{
	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
}

5991 5992 5993 5994 5995
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
	return security_sid_to_context(secid, secdata, seclen);
}

5996
static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5997
{
5998
	return security_context_to_sid(secdata, seclen, secid, GFP_KERNEL);
5999 6000
}

6001 6002
static void selinux_release_secctx(char *secdata, u32 seclen)
{
6003
	kfree(secdata);
6004 6005
}

6006 6007 6008 6009
static void selinux_inode_invalidate_secctx(struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;

6010
	spin_lock(&isec->lock);
6011
	isec->initialized = LABEL_INVALID;
6012
	spin_unlock(&isec->lock);
6013 6014
}

6015 6016 6017 6018 6019 6020 6021 6022 6023 6024 6025 6026 6027 6028 6029 6030 6031 6032 6033 6034 6035 6036 6037 6038 6039 6040
/*
 *	called with inode->i_mutex locked
 */
static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
{
	return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
}

/*
 *	called with inode->i_mutex locked
 */
static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
{
	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
}

static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
{
	int len = 0;
	len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
						ctx, true);
	if (len < 0)
		return len;
	*ctxlen = len;
	return 0;
}
6041 6042
#ifdef CONFIG_KEYS

D
David Howells 已提交
6043
static int selinux_key_alloc(struct key *k, const struct cred *cred,
6044
			     unsigned long flags)
6045
{
D
David Howells 已提交
6046
	const struct task_security_struct *tsec;
6047 6048 6049 6050 6051 6052
	struct key_security_struct *ksec;

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

D
David Howells 已提交
6053 6054 6055
	tsec = cred->security;
	if (tsec->keycreate_sid)
		ksec->sid = tsec->keycreate_sid;
6056
	else
D
David Howells 已提交
6057
		ksec->sid = tsec->sid;
6058

6059
	k->security = ksec;
6060 6061 6062 6063 6064 6065 6066 6067 6068 6069 6070 6071
	return 0;
}

static void selinux_key_free(struct key *k)
{
	struct key_security_struct *ksec = k->security;

	k->security = NULL;
	kfree(ksec);
}

static int selinux_key_permission(key_ref_t key_ref,
D
David Howells 已提交
6072
				  const struct cred *cred,
6073
				  unsigned perm)
6074 6075 6076
{
	struct key *key;
	struct key_security_struct *ksec;
6077
	u32 sid;
6078 6079 6080 6081 6082 6083 6084

	/* if no specific permissions are requested, we skip the
	   permission check. No serious, additional covert channels
	   appear to be created. */
	if (perm == 0)
		return 0;

D
David Howells 已提交
6085
	sid = cred_sid(cred);
6086 6087 6088 6089 6090

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

	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
6091 6092
}

6093 6094 6095 6096 6097 6098 6099 6100 6101 6102 6103 6104 6105 6106
static int selinux_key_getsecurity(struct key *key, char **_buffer)
{
	struct key_security_struct *ksec = key->security;
	char *context = NULL;
	unsigned len;
	int rc;

	rc = security_sid_to_context(ksec->sid, &context, &len);
	if (!rc)
		rc = len;
	*_buffer = context;
	return rc;
}

6107 6108
#endif

C
Casey Schaufler 已提交
6109
static struct security_hook_list selinux_hooks[] = {
6110 6111 6112 6113 6114 6115 6116 6117 6118 6119 6120 6121 6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132 6133 6134 6135 6136 6137 6138 6139 6140 6141 6142 6143 6144 6145
	LSM_HOOK_INIT(binder_set_context_mgr, selinux_binder_set_context_mgr),
	LSM_HOOK_INIT(binder_transaction, selinux_binder_transaction),
	LSM_HOOK_INIT(binder_transfer_binder, selinux_binder_transfer_binder),
	LSM_HOOK_INIT(binder_transfer_file, selinux_binder_transfer_file),

	LSM_HOOK_INIT(ptrace_access_check, selinux_ptrace_access_check),
	LSM_HOOK_INIT(ptrace_traceme, selinux_ptrace_traceme),
	LSM_HOOK_INIT(capget, selinux_capget),
	LSM_HOOK_INIT(capset, selinux_capset),
	LSM_HOOK_INIT(capable, selinux_capable),
	LSM_HOOK_INIT(quotactl, selinux_quotactl),
	LSM_HOOK_INIT(quota_on, selinux_quota_on),
	LSM_HOOK_INIT(syslog, selinux_syslog),
	LSM_HOOK_INIT(vm_enough_memory, selinux_vm_enough_memory),

	LSM_HOOK_INIT(netlink_send, selinux_netlink_send),

	LSM_HOOK_INIT(bprm_set_creds, selinux_bprm_set_creds),
	LSM_HOOK_INIT(bprm_committing_creds, selinux_bprm_committing_creds),
	LSM_HOOK_INIT(bprm_committed_creds, selinux_bprm_committed_creds),
	LSM_HOOK_INIT(bprm_secureexec, selinux_bprm_secureexec),

	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
	LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
	LSM_HOOK_INIT(sb_copy_data, selinux_sb_copy_data),
	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
	LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
	LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
	LSM_HOOK_INIT(sb_statfs, selinux_sb_statfs),
	LSM_HOOK_INIT(sb_mount, selinux_mount),
	LSM_HOOK_INIT(sb_umount, selinux_umount),
	LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
	LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
	LSM_HOOK_INIT(sb_parse_opts_str, selinux_parse_opts_str),

	LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
6146
	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
6147 6148 6149 6150 6151 6152 6153 6154 6155 6156 6157 6158 6159 6160 6161 6162 6163 6164 6165 6166 6167 6168 6169 6170 6171 6172

	LSM_HOOK_INIT(inode_alloc_security, selinux_inode_alloc_security),
	LSM_HOOK_INIT(inode_free_security, selinux_inode_free_security),
	LSM_HOOK_INIT(inode_init_security, selinux_inode_init_security),
	LSM_HOOK_INIT(inode_create, selinux_inode_create),
	LSM_HOOK_INIT(inode_link, selinux_inode_link),
	LSM_HOOK_INIT(inode_unlink, selinux_inode_unlink),
	LSM_HOOK_INIT(inode_symlink, selinux_inode_symlink),
	LSM_HOOK_INIT(inode_mkdir, selinux_inode_mkdir),
	LSM_HOOK_INIT(inode_rmdir, selinux_inode_rmdir),
	LSM_HOOK_INIT(inode_mknod, selinux_inode_mknod),
	LSM_HOOK_INIT(inode_rename, selinux_inode_rename),
	LSM_HOOK_INIT(inode_readlink, selinux_inode_readlink),
	LSM_HOOK_INIT(inode_follow_link, selinux_inode_follow_link),
	LSM_HOOK_INIT(inode_permission, selinux_inode_permission),
	LSM_HOOK_INIT(inode_setattr, selinux_inode_setattr),
	LSM_HOOK_INIT(inode_getattr, selinux_inode_getattr),
	LSM_HOOK_INIT(inode_setxattr, selinux_inode_setxattr),
	LSM_HOOK_INIT(inode_post_setxattr, selinux_inode_post_setxattr),
	LSM_HOOK_INIT(inode_getxattr, selinux_inode_getxattr),
	LSM_HOOK_INIT(inode_listxattr, selinux_inode_listxattr),
	LSM_HOOK_INIT(inode_removexattr, selinux_inode_removexattr),
	LSM_HOOK_INIT(inode_getsecurity, selinux_inode_getsecurity),
	LSM_HOOK_INIT(inode_setsecurity, selinux_inode_setsecurity),
	LSM_HOOK_INIT(inode_listsecurity, selinux_inode_listsecurity),
	LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid),
6173
	LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up),
6174
	LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr),
6175 6176 6177 6178 6179 6180 6181 6182 6183 6184 6185 6186 6187 6188 6189 6190 6191 6192 6193 6194 6195 6196 6197 6198

	LSM_HOOK_INIT(file_permission, selinux_file_permission),
	LSM_HOOK_INIT(file_alloc_security, selinux_file_alloc_security),
	LSM_HOOK_INIT(file_free_security, selinux_file_free_security),
	LSM_HOOK_INIT(file_ioctl, selinux_file_ioctl),
	LSM_HOOK_INIT(mmap_file, selinux_mmap_file),
	LSM_HOOK_INIT(mmap_addr, selinux_mmap_addr),
	LSM_HOOK_INIT(file_mprotect, selinux_file_mprotect),
	LSM_HOOK_INIT(file_lock, selinux_file_lock),
	LSM_HOOK_INIT(file_fcntl, selinux_file_fcntl),
	LSM_HOOK_INIT(file_set_fowner, selinux_file_set_fowner),
	LSM_HOOK_INIT(file_send_sigiotask, selinux_file_send_sigiotask),
	LSM_HOOK_INIT(file_receive, selinux_file_receive),

	LSM_HOOK_INIT(file_open, selinux_file_open),

	LSM_HOOK_INIT(task_create, selinux_task_create),
	LSM_HOOK_INIT(cred_alloc_blank, selinux_cred_alloc_blank),
	LSM_HOOK_INIT(cred_free, selinux_cred_free),
	LSM_HOOK_INIT(cred_prepare, selinux_cred_prepare),
	LSM_HOOK_INIT(cred_transfer, selinux_cred_transfer),
	LSM_HOOK_INIT(kernel_act_as, selinux_kernel_act_as),
	LSM_HOOK_INIT(kernel_create_files_as, selinux_kernel_create_files_as),
	LSM_HOOK_INIT(kernel_module_request, selinux_kernel_module_request),
6199
	LSM_HOOK_INIT(kernel_read_file, selinux_kernel_read_file),
6200 6201 6202 6203 6204 6205 6206 6207 6208 6209 6210 6211 6212 6213 6214 6215 6216 6217 6218 6219 6220 6221 6222 6223 6224 6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236 6237 6238 6239 6240 6241 6242 6243 6244 6245 6246 6247 6248
	LSM_HOOK_INIT(task_setpgid, selinux_task_setpgid),
	LSM_HOOK_INIT(task_getpgid, selinux_task_getpgid),
	LSM_HOOK_INIT(task_getsid, selinux_task_getsid),
	LSM_HOOK_INIT(task_getsecid, selinux_task_getsecid),
	LSM_HOOK_INIT(task_setnice, selinux_task_setnice),
	LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio),
	LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio),
	LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit),
	LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler),
	LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler),
	LSM_HOOK_INIT(task_movememory, selinux_task_movememory),
	LSM_HOOK_INIT(task_kill, selinux_task_kill),
	LSM_HOOK_INIT(task_to_inode, selinux_task_to_inode),

	LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
	LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),

	LSM_HOOK_INIT(msg_msg_alloc_security, selinux_msg_msg_alloc_security),
	LSM_HOOK_INIT(msg_msg_free_security, selinux_msg_msg_free_security),

	LSM_HOOK_INIT(msg_queue_alloc_security,
			selinux_msg_queue_alloc_security),
	LSM_HOOK_INIT(msg_queue_free_security, selinux_msg_queue_free_security),
	LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
	LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
	LSM_HOOK_INIT(msg_queue_msgsnd, selinux_msg_queue_msgsnd),
	LSM_HOOK_INIT(msg_queue_msgrcv, selinux_msg_queue_msgrcv),

	LSM_HOOK_INIT(shm_alloc_security, selinux_shm_alloc_security),
	LSM_HOOK_INIT(shm_free_security, selinux_shm_free_security),
	LSM_HOOK_INIT(shm_associate, selinux_shm_associate),
	LSM_HOOK_INIT(shm_shmctl, selinux_shm_shmctl),
	LSM_HOOK_INIT(shm_shmat, selinux_shm_shmat),

	LSM_HOOK_INIT(sem_alloc_security, selinux_sem_alloc_security),
	LSM_HOOK_INIT(sem_free_security, selinux_sem_free_security),
	LSM_HOOK_INIT(sem_associate, selinux_sem_associate),
	LSM_HOOK_INIT(sem_semctl, selinux_sem_semctl),
	LSM_HOOK_INIT(sem_semop, selinux_sem_semop),

	LSM_HOOK_INIT(d_instantiate, selinux_d_instantiate),

	LSM_HOOK_INIT(getprocattr, selinux_getprocattr),
	LSM_HOOK_INIT(setprocattr, selinux_setprocattr),

	LSM_HOOK_INIT(ismaclabel, selinux_ismaclabel),
	LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
	LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
	LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
6249
	LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
6250 6251 6252 6253 6254 6255 6256 6257 6258 6259 6260 6261 6262 6263 6264 6265 6266 6267 6268 6269 6270 6271 6272 6273 6274 6275 6276 6277 6278 6279 6280 6281 6282 6283 6284 6285 6286 6287 6288 6289 6290 6291
	LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
	LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
	LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),

	LSM_HOOK_INIT(unix_stream_connect, selinux_socket_unix_stream_connect),
	LSM_HOOK_INIT(unix_may_send, selinux_socket_unix_may_send),

	LSM_HOOK_INIT(socket_create, selinux_socket_create),
	LSM_HOOK_INIT(socket_post_create, selinux_socket_post_create),
	LSM_HOOK_INIT(socket_bind, selinux_socket_bind),
	LSM_HOOK_INIT(socket_connect, selinux_socket_connect),
	LSM_HOOK_INIT(socket_listen, selinux_socket_listen),
	LSM_HOOK_INIT(socket_accept, selinux_socket_accept),
	LSM_HOOK_INIT(socket_sendmsg, selinux_socket_sendmsg),
	LSM_HOOK_INIT(socket_recvmsg, selinux_socket_recvmsg),
	LSM_HOOK_INIT(socket_getsockname, selinux_socket_getsockname),
	LSM_HOOK_INIT(socket_getpeername, selinux_socket_getpeername),
	LSM_HOOK_INIT(socket_getsockopt, selinux_socket_getsockopt),
	LSM_HOOK_INIT(socket_setsockopt, selinux_socket_setsockopt),
	LSM_HOOK_INIT(socket_shutdown, selinux_socket_shutdown),
	LSM_HOOK_INIT(socket_sock_rcv_skb, selinux_socket_sock_rcv_skb),
	LSM_HOOK_INIT(socket_getpeersec_stream,
			selinux_socket_getpeersec_stream),
	LSM_HOOK_INIT(socket_getpeersec_dgram, selinux_socket_getpeersec_dgram),
	LSM_HOOK_INIT(sk_alloc_security, selinux_sk_alloc_security),
	LSM_HOOK_INIT(sk_free_security, selinux_sk_free_security),
	LSM_HOOK_INIT(sk_clone_security, selinux_sk_clone_security),
	LSM_HOOK_INIT(sk_getsecid, selinux_sk_getsecid),
	LSM_HOOK_INIT(sock_graft, selinux_sock_graft),
	LSM_HOOK_INIT(inet_conn_request, selinux_inet_conn_request),
	LSM_HOOK_INIT(inet_csk_clone, selinux_inet_csk_clone),
	LSM_HOOK_INIT(inet_conn_established, selinux_inet_conn_established),
	LSM_HOOK_INIT(secmark_relabel_packet, selinux_secmark_relabel_packet),
	LSM_HOOK_INIT(secmark_refcount_inc, selinux_secmark_refcount_inc),
	LSM_HOOK_INIT(secmark_refcount_dec, selinux_secmark_refcount_dec),
	LSM_HOOK_INIT(req_classify_flow, selinux_req_classify_flow),
	LSM_HOOK_INIT(tun_dev_alloc_security, selinux_tun_dev_alloc_security),
	LSM_HOOK_INIT(tun_dev_free_security, selinux_tun_dev_free_security),
	LSM_HOOK_INIT(tun_dev_create, selinux_tun_dev_create),
	LSM_HOOK_INIT(tun_dev_attach_queue, selinux_tun_dev_attach_queue),
	LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
6292 6293

#ifdef CONFIG_SECURITY_NETWORK_XFRM
6294 6295 6296 6297 6298 6299 6300 6301 6302 6303 6304 6305 6306
	LSM_HOOK_INIT(xfrm_policy_alloc_security, selinux_xfrm_policy_alloc),
	LSM_HOOK_INIT(xfrm_policy_clone_security, selinux_xfrm_policy_clone),
	LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
	LSM_HOOK_INIT(xfrm_policy_delete_security, selinux_xfrm_policy_delete),
	LSM_HOOK_INIT(xfrm_state_alloc, selinux_xfrm_state_alloc),
	LSM_HOOK_INIT(xfrm_state_alloc_acquire,
			selinux_xfrm_state_alloc_acquire),
	LSM_HOOK_INIT(xfrm_state_free_security, selinux_xfrm_state_free),
	LSM_HOOK_INIT(xfrm_state_delete_security, selinux_xfrm_state_delete),
	LSM_HOOK_INIT(xfrm_policy_lookup, selinux_xfrm_policy_lookup),
	LSM_HOOK_INIT(xfrm_state_pol_flow_match,
			selinux_xfrm_state_pol_flow_match),
	LSM_HOOK_INIT(xfrm_decode_session, selinux_xfrm_decode_session),
L
Linus Torvalds 已提交
6307
#endif
6308 6309

#ifdef CONFIG_KEYS
6310 6311 6312 6313
	LSM_HOOK_INIT(key_alloc, selinux_key_alloc),
	LSM_HOOK_INIT(key_free, selinux_key_free),
	LSM_HOOK_INIT(key_permission, selinux_key_permission),
	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
6314
#endif
6315 6316

#ifdef CONFIG_AUDIT
6317 6318 6319 6320
	LSM_HOOK_INIT(audit_rule_init, selinux_audit_rule_init),
	LSM_HOOK_INIT(audit_rule_known, selinux_audit_rule_known),
	LSM_HOOK_INIT(audit_rule_match, selinux_audit_rule_match),
	LSM_HOOK_INIT(audit_rule_free, selinux_audit_rule_free),
6321
#endif
L
Linus Torvalds 已提交
6322 6323 6324 6325
};

static __init int selinux_init(void)
{
C
Casey Schaufler 已提交
6326
	if (!security_module_enable("selinux")) {
6327 6328 6329 6330
		selinux_enabled = 0;
		return 0;
	}

L
Linus Torvalds 已提交
6331 6332 6333 6334 6335 6336 6337 6338
	if (!selinux_enabled) {
		printk(KERN_INFO "SELinux:  Disabled at boot.\n");
		return 0;
	}

	printk(KERN_INFO "SELinux:  Initializing.\n");

	/* Set the security state for the initial task. */
D
David Howells 已提交
6339
	cred_init_security();
L
Linus Torvalds 已提交
6340

6341 6342
	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);

6343 6344
	sel_inode_cache = kmem_cache_create("selinux_inode_security",
					    sizeof(struct inode_security_struct),
6345
					    0, SLAB_PANIC, NULL);
6346 6347 6348
	file_security_cache = kmem_cache_create("selinux_file_security",
					    sizeof(struct file_security_struct),
					    0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
6349 6350
	avc_init();

6351
	security_add_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks), "selinux");
L
Linus Torvalds 已提交
6352

6353 6354 6355
	if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET))
		panic("SELinux: Unable to register AVC netcache callback\n");

6356
	if (selinux_enforcing)
6357
		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
6358
	else
6359
		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
6360

L
Linus Torvalds 已提交
6361 6362 6363
	return 0;
}

6364 6365 6366 6367 6368
static void delayed_superblock_init(struct super_block *sb, void *unused)
{
	superblock_doinit(sb, NULL);
}

L
Linus Torvalds 已提交
6369 6370
void selinux_complete_init(void)
{
6371
	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
L
Linus Torvalds 已提交
6372 6373

	/* Set up any superblocks initialized prior to the policy load. */
6374
	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
6375
	iterate_supers(delayed_superblock_init, NULL);
L
Linus Torvalds 已提交
6376 6377 6378 6379 6380 6381
}

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

6382
#if defined(CONFIG_NETFILTER)
L
Linus Torvalds 已提交
6383

6384
static struct nf_hook_ops selinux_nf_ops[] = {
6385 6386
	{
		.hook =		selinux_ipv4_postroute,
6387
		.pf =		NFPROTO_IPV4,
6388 6389 6390 6391 6392
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv4_forward,
6393
		.pf =		NFPROTO_IPV4,
6394 6395
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
6396 6397 6398
	},
	{
		.hook =		selinux_ipv4_output,
6399
		.pf =		NFPROTO_IPV4,
6400 6401
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
6402
	},
6403
#if IS_ENABLED(CONFIG_IPV6)
6404 6405
	{
		.hook =		selinux_ipv6_postroute,
6406
		.pf =		NFPROTO_IPV6,
6407 6408 6409 6410 6411
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP6_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv6_forward,
6412
		.pf =		NFPROTO_IPV6,
6413 6414
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
6415
	},
6416 6417 6418 6419 6420 6421
	{
		.hook =		selinux_ipv6_output,
		.pf =		NFPROTO_IPV6,
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
	},
L
Linus Torvalds 已提交
6422
#endif	/* IPV6 */
6423
};
L
Linus Torvalds 已提交
6424 6425 6426

static int __init selinux_nf_ip_init(void)
{
6427
	int err;
L
Linus Torvalds 已提交
6428 6429

	if (!selinux_enabled)
6430
		return 0;
6431 6432 6433

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

6434
	err = nf_register_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
6435
	if (err)
6436
		panic("SELinux: nf_register_hooks: error %d\n", err);
L
Linus Torvalds 已提交
6437

6438
	return 0;
L
Linus Torvalds 已提交
6439 6440 6441 6442 6443 6444 6445
}

__initcall(selinux_nf_ip_init);

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static void selinux_nf_ip_exit(void)
{
6446
	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
L
Linus Torvalds 已提交
6447

6448
	nf_unregister_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
L
Linus Torvalds 已提交
6449 6450 6451
}
#endif

6452
#else /* CONFIG_NETFILTER */
L
Linus Torvalds 已提交
6453 6454 6455 6456 6457

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
#define selinux_nf_ip_exit()
#endif

6458
#endif /* CONFIG_NETFILTER */
L
Linus Torvalds 已提交
6459 6460

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
6461 6462
static int selinux_disabled;

L
Linus Torvalds 已提交
6463 6464 6465 6466 6467 6468 6469 6470 6471 6472 6473 6474 6475 6476 6477
int selinux_disable(void)
{
	if (ss_initialized) {
		/* Not permitted after initial policy load. */
		return -EINVAL;
	}

	if (selinux_disabled) {
		/* Only do this once. */
		return -EINVAL;
	}

	printk(KERN_INFO "SELinux:  Disabled at runtime.\n");

	selinux_disabled = 1;
6478
	selinux_enabled = 0;
L
Linus Torvalds 已提交
6479

C
Casey Schaufler 已提交
6480
	security_delete_hooks(selinux_hooks, ARRAY_SIZE(selinux_hooks));
L
Linus Torvalds 已提交
6481

6482 6483 6484
	/* Try to destroy the avc node cache */
	avc_disable();

L
Linus Torvalds 已提交
6485 6486 6487 6488 6489 6490 6491 6492 6493
	/* Unregister netfilter hooks. */
	selinux_nf_ip_exit();

	/* Unregister selinuxfs. */
	exit_sel_fs();

	return 0;
}
#endif