hooks.c 150.0 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 31 32 33 34 35 36 37 38 39
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/security.h>
#include <linux/xattr.h>
#include <linux/capability.h>
#include <linux/unistd.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
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[] */
54
#include <net/sock.h>
L
Linus Torvalds 已提交
55
#include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */
56
#include <net/inet_connection_sock.h>
57
#include <net/net_namespace.h>
58
#include <net/netlabel.h>
59
#include <linux/uaccess.h>
L
Linus Torvalds 已提交
60
#include <asm/ioctls.h>
A
Arun Sharma 已提交
61
#include <linux/atomic.h>
L
Linus Torvalds 已提交
62 63 64
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>	/* for network interface checks */
65
#include <net/netlink.h>
L
Linus Torvalds 已提交
66 67
#include <linux/tcp.h>
#include <linux/udp.h>
J
James Morris 已提交
68
#include <linux/dccp.h>
L
Linus Torvalds 已提交
69 70 71 72 73 74 75 76 77
#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>
78
#include <linux/string.h>
C
Catherine Zhang 已提交
79
#include <linux/selinux.h>
80
#include <linux/mutex.h>
81
#include <linux/posix-timers.h>
82
#include <linux/syslog.h>
83
#include <linux/user_namespace.h>
84
#include <linux/export.h>
85
#include <linux/security.h>
A
Al Viro 已提交
86 87
#include <linux/msg.h>
#include <linux/shm.h>
L
Linus Torvalds 已提交
88 89 90 91

#include "avc.h"
#include "objsec.h"
#include "netif.h"
92
#include "netnode.h"
P
Paul Moore 已提交
93
#include "netport.h"
94
#include "xfrm.h"
95
#include "netlabel.h"
96
#include "audit.h"
97
#include "avc_ss.h"
L
Linus Torvalds 已提交
98

99
extern struct security_operations *security_ops;
L
Linus Torvalds 已提交
100

101
/* SECMARK reference count */
102
static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
103

L
Linus Torvalds 已提交
104
#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
105
int selinux_enforcing;
L
Linus Torvalds 已提交
106 107 108

static int __init enforcing_setup(char *str)
{
109 110 111
	unsigned long enforcing;
	if (!strict_strtoul(str, 0, &enforcing))
		selinux_enforcing = enforcing ? 1 : 0;
L
Linus Torvalds 已提交
112 113 114 115 116 117 118 119 120 121
	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)
{
122 123 124
	unsigned long enabled;
	if (!strict_strtoul(str, 0, &enabled))
		selinux_enabled = enabled ? 1 : 0;
L
Linus Torvalds 已提交
125 126 127
	return 1;
}
__setup("selinux=", selinux_enabled_setup);
128 129
#else
int selinux_enabled = 1;
L
Linus Torvalds 已提交
130 131
#endif

132
static struct kmem_cache *sel_inode_cache;
133

134 135 136 137 138 139 140
/**
 * 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
141 142
 * enabled, false (0) if SECMARK is disabled.  If the always_check_network
 * policy capability is enabled, SECMARK is always considered enabled.
143 144 145 146
 *
 */
static int selinux_secmark_enabled(void)
{
147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162
	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());
163 164
}

D
David Howells 已提交
165 166 167 168
/*
 * initialise the security for the init task
 */
static void cred_init_security(void)
L
Linus Torvalds 已提交
169
{
170
	struct cred *cred = (struct cred *) current->real_cred;
L
Linus Torvalds 已提交
171 172
	struct task_security_struct *tsec;

J
James Morris 已提交
173
	tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
174
	if (!tsec)
D
David Howells 已提交
175
		panic("SELinux:  Failed to initialize initial task.\n");
L
Linus Torvalds 已提交
176

D
David Howells 已提交
177
	tsec->osid = tsec->sid = SECINITSID_KERNEL;
178
	cred->security = tsec;
L
Linus Torvalds 已提交
179 180
}

181 182 183 184 185 186 187 188 189 190 191
/*
 * 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;
}

192
/*
193
 * get the objective security ID of a task
194 195 196 197 198 199
 */
static inline u32 task_sid(const struct task_struct *task)
{
	u32 sid;

	rcu_read_lock();
200
	sid = cred_sid(__task_cred(task));
201 202 203 204 205
	rcu_read_unlock();
	return sid;
}

/*
206
 * get the subjective security ID of the current task
207 208 209
 */
static inline u32 current_sid(void)
{
210
	const struct task_security_struct *tsec = current_security();
211 212 213 214

	return tsec->sid;
}

215 216
/* Allocate and free functions for each kind of security blob. */

L
Linus Torvalds 已提交
217 218 219
static int inode_alloc_security(struct inode *inode)
{
	struct inode_security_struct *isec;
220
	u32 sid = current_sid();
L
Linus Torvalds 已提交
221

222
	isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
L
Linus Torvalds 已提交
223 224 225
	if (!isec)
		return -ENOMEM;

226
	mutex_init(&isec->lock);
L
Linus Torvalds 已提交
227 228 229 230
	INIT_LIST_HEAD(&isec->list);
	isec->inode = inode;
	isec->sid = SECINITSID_UNLABELED;
	isec->sclass = SECCLASS_FILE;
231
	isec->task_sid = sid;
L
Linus Torvalds 已提交
232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247
	inode->i_security = isec;

	return 0;
}

static void inode_free_security(struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec = inode->i_sb->s_security;

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

	inode->i_security = NULL;
248
	kmem_cache_free(sel_inode_cache, isec);
L
Linus Torvalds 已提交
249 250 251 252 253
}

static int file_alloc_security(struct file *file)
{
	struct file_security_struct *fsec;
254
	u32 sid = current_sid();
L
Linus Torvalds 已提交
255

256
	fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
257 258 259
	if (!fsec)
		return -ENOMEM;

260 261
	fsec->sid = sid;
	fsec->fown_sid = sid;
L
Linus Torvalds 已提交
262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277
	file->f_security = fsec;

	return 0;
}

static void file_free_security(struct file *file)
{
	struct file_security_struct *fsec = file->f_security;
	file->f_security = NULL;
	kfree(fsec);
}

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

J
James Morris 已提交
278
	sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
279 280 281
	if (!sbsec)
		return -ENOMEM;

282
	mutex_init(&sbsec->lock);
L
Linus Torvalds 已提交
283 284 285 286 287
	INIT_LIST_HEAD(&sbsec->isec_head);
	spin_lock_init(&sbsec->isec_lock);
	sbsec->sb = sb;
	sbsec->sid = SECINITSID_UNLABELED;
	sbsec->def_sid = SECINITSID_FILE;
288
	sbsec->mntpoint_sid = SECINITSID_UNLABELED;
L
Linus Torvalds 已提交
289 290 291 292 293 294 295 296 297 298 299 300 301 302
	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. */

303
static const char *labeling_behaviors[7] = {
L
Linus Torvalds 已提交
304 305 306 307 308 309
	"uses xattr",
	"uses transition SIDs",
	"uses task SIDs",
	"uses genfs_contexts",
	"not configured for labeling",
	"uses mountpoint labeling",
310
	"uses native labeling",
L
Linus Torvalds 已提交
311 312 313 314 315 316 317 318 319 320
};

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

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

enum {
321
	Opt_error = -1,
L
Linus Torvalds 已提交
322 323
	Opt_context = 1,
	Opt_fscontext = 2,
324 325
	Opt_defcontext = 3,
	Opt_rootcontext = 4,
326
	Opt_labelsupport = 5,
327
	Opt_nextmntopt = 6,
L
Linus Torvalds 已提交
328 329
};

330 331
#define NUM_SEL_MNT_OPTS	(Opt_nextmntopt - 1)

332
static const match_table_t tokens = {
333 334 335 336
	{Opt_context, CONTEXT_STR "%s"},
	{Opt_fscontext, FSCONTEXT_STR "%s"},
	{Opt_defcontext, DEFCONTEXT_STR "%s"},
	{Opt_rootcontext, ROOTCONTEXT_STR "%s"},
337
	{Opt_labelsupport, LABELSUPP_STR},
338
	{Opt_error, NULL},
L
Linus Torvalds 已提交
339 340 341 342
};

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

343 344
static int may_context_mount_sb_relabel(u32 sid,
			struct superblock_security_struct *sbsec,
345
			const struct cred *cred)
346
{
347
	const struct task_security_struct *tsec = cred->security;
348 349 350 351 352 353 354 355 356 357 358 359
	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;
}

360 361
static int may_context_mount_inode_relabel(u32 sid,
			struct superblock_security_struct *sbsec,
362
			const struct cred *cred)
363
{
364
	const struct task_security_struct *tsec = cred->security;
365 366 367 368 369 370 371 372 373 374 375
	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;
}

376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398
static int selinux_is_sblabel_mnt(struct super_block *sb)
{
	struct superblock_security_struct *sbsec = sb->s_security;

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

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

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

	return 0;
}

399
static int sb_finish_set_opts(struct super_block *sb)
L
Linus Torvalds 已提交
400 401
{
	struct superblock_security_struct *sbsec = sb->s_security;
402 403 404
	struct dentry *root = sb->s_root;
	struct inode *root_inode = root->d_inode;
	int rc = 0;
L
Linus Torvalds 已提交
405

406 407 408 409 410 411 412
	if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
		/* Make sure that the xattr handler exists and that no
		   error other than -ENODATA is returned by getxattr on
		   the root directory.  -ENODATA is ok, as this may be
		   the first boot of the SELinux kernel before we have
		   assigned xattr values to the filesystem. */
		if (!root_inode->i_op->getxattr) {
413 414
			printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
			       "xattr support\n", sb->s_id, sb->s_type->name);
415 416 417 418 419 420 421
			rc = -EOPNOTSUPP;
			goto out;
		}
		rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
		if (rc < 0 && rc != -ENODATA) {
			if (rc == -EOPNOTSUPP)
				printk(KERN_WARNING "SELinux: (dev %s, type "
422 423
				       "%s) has no security xattr handler\n",
				       sb->s_id, sb->s_type->name);
424 425
			else
				printk(KERN_WARNING "SELinux: (dev %s, type "
426 427
				       "%s) getxattr errno %d\n", sb->s_id,
				       sb->s_type->name, -rc);
428 429 430
			goto out;
		}
	}
L
Linus Torvalds 已提交
431

432
	if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
433 434
		printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
		       sb->s_id, sb->s_type->name);
435
	else
436 437
		printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
		       sb->s_id, sb->s_type->name,
438
		       labeling_behaviors[sbsec->behavior-1]);
L
Linus Torvalds 已提交
439

440
	sbsec->flags |= SE_SBINITIALIZED;
441
	if (selinux_is_sblabel_mnt(sb))
442
		sbsec->flags |= SBLABEL_MNT;
443

444 445
	/* Initialize the root inode. */
	rc = inode_doinit_with_dentry(root_inode, root);
L
Linus Torvalds 已提交
446

447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472
	/* Initialize any other inodes associated with the superblock, e.g.
	   inodes created prior to initial policy load or inodes created
	   during get_sb by a pseudo filesystem that directly
	   populates itself. */
	spin_lock(&sbsec->isec_lock);
next_inode:
	if (!list_empty(&sbsec->isec_head)) {
		struct inode_security_struct *isec =
				list_entry(sbsec->isec_head.next,
					   struct inode_security_struct, list);
		struct inode *inode = isec->inode;
		spin_unlock(&sbsec->isec_lock);
		inode = igrab(inode);
		if (inode) {
			if (!IS_PRIVATE(inode))
				inode_doinit(inode);
			iput(inode);
		}
		spin_lock(&sbsec->isec_lock);
		list_del_init(&isec->list);
		goto next_inode;
	}
	spin_unlock(&sbsec->isec_lock);
out:
	return rc;
}
L
Linus Torvalds 已提交
473

474 475 476 477 478 479
/*
 * 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,
480
				struct security_mnt_opts *opts)
481 482 483 484 485 486
{
	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
487

488
	security_init_mnt_opts(opts);
L
Linus Torvalds 已提交
489

490
	if (!(sbsec->flags & SE_SBINITIALIZED))
491
		return -EINVAL;
L
Linus Torvalds 已提交
492

493 494
	if (!ss_initialized)
		return -EINVAL;
L
Linus Torvalds 已提交
495

496 497 498
	/* make sure we always check enough bits to cover the mask */
	BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS));

499
	tmp = sbsec->flags & SE_MNTMASK;
500
	/* count the number of mount options for this sb */
501
	for (i = 0; i < NUM_SEL_MNT_OPTS; i++) {
502
		if (tmp & 0x01)
503
			opts->num_mnt_opts++;
504 505
		tmp >>= 1;
	}
506
	/* Check if the Label support flag is set */
507
	if (sbsec->flags & SBLABEL_MNT)
508
		opts->num_mnt_opts++;
L
Linus Torvalds 已提交
509

510 511
	opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts) {
512 513 514
		rc = -ENOMEM;
		goto out_free;
	}
L
Linus Torvalds 已提交
515

516 517
	opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
	if (!opts->mnt_opts_flags) {
518 519 520
		rc = -ENOMEM;
		goto out_free;
	}
L
Linus Torvalds 已提交
521

522 523 524 525 526
	i = 0;
	if (sbsec->flags & FSCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->sid, &context, &len);
		if (rc)
			goto out_free;
527 528
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
529 530 531 532 533
	}
	if (sbsec->flags & CONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
		if (rc)
			goto out_free;
534 535
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = CONTEXT_MNT;
536 537 538 539 540
	}
	if (sbsec->flags & DEFCONTEXT_MNT) {
		rc = security_sid_to_context(sbsec->def_sid, &context, &len);
		if (rc)
			goto out_free;
541 542
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
543 544 545 546
	}
	if (sbsec->flags & ROOTCONTEXT_MNT) {
		struct inode *root = sbsec->sb->s_root->d_inode;
		struct inode_security_struct *isec = root->i_security;
547

548 549 550
		rc = security_sid_to_context(isec->sid, &context, &len);
		if (rc)
			goto out_free;
551 552
		opts->mnt_opts[i] = context;
		opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
553
	}
554
	if (sbsec->flags & SBLABEL_MNT) {
555
		opts->mnt_opts[i] = NULL;
556
		opts->mnt_opts_flags[i++] = SBLABEL_MNT;
557
	}
L
Linus Torvalds 已提交
558

559
	BUG_ON(i != opts->num_mnt_opts);
L
Linus Torvalds 已提交
560

561 562 563
	return 0;

out_free:
564
	security_free_mnt_opts(opts);
565 566
	return rc;
}
L
Linus Torvalds 已提交
567

568 569 570
static int bad_option(struct superblock_security_struct *sbsec, char flag,
		      u32 old_sid, u32 new_sid)
{
571 572
	char mnt_flags = sbsec->flags & SE_MNTMASK;

573
	/* check if the old mount command had the same options */
574
	if (sbsec->flags & SE_SBINITIALIZED)
575 576 577 578 579 580 581
		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
	 */
582 583
	if (!(sbsec->flags & SE_SBINITIALIZED))
		if (mnt_flags & flag)
584 585 586
			return 1;
	return 0;
}
587

588 589 590 591
/*
 * Allow filesystems with binary mount data to explicitly set mount point
 * labeling information.
 */
592
static int selinux_set_mnt_opts(struct super_block *sb,
593 594 595
				struct security_mnt_opts *opts,
				unsigned long kern_flags,
				unsigned long *set_kern_flags)
596
{
597
	const struct cred *cred = current_cred();
598 599
	int rc = 0, i;
	struct superblock_security_struct *sbsec = sb->s_security;
600
	const char *name = sb->s_type->name;
601 602
	struct inode *inode = sbsec->sb->s_root->d_inode;
	struct inode_security_struct *root_isec = inode->i_security;
603 604
	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
	u32 defcontext_sid = 0;
605 606 607
	char **mount_options = opts->mnt_opts;
	int *flags = opts->mnt_opts_flags;
	int num_opts = opts->num_mnt_opts;
608 609 610 611 612 613 614 615 616 617 618

	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
619 620
		printk(KERN_WARNING "SELinux: Unable to set superblock options "
			"before the security server is initialized\n");
L
Linus Torvalds 已提交
621
		goto out;
622
	}
623 624 625 626 627 628
	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
629

630 631 632 633 634 635 636 637 638 639 640
	/*
	 * 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)
	 */
641
	if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
642
	    && (num_opts == 0))
643
		goto out;
644

645 646 647 648 649 650 651
	/*
	 * 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;
652

653
		if (flags[i] == SBLABEL_MNT)
654
			continue;
655 656
		rc = security_context_to_sid(mount_options[i],
					     strlen(mount_options[i]), &sid);
L
Linus Torvalds 已提交
657 658
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
659 660
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, name, rc);
661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704
			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
705
		}
706 707
	}

708
	if (sbsec->flags & SE_SBINITIALIZED) {
709
		/* previously mounted with options, but not on this attempt? */
710
		if ((sbsec->flags & SE_MNTMASK) && !num_opts)
711 712 713 714 715
			goto out_double_mount;
		rc = 0;
		goto out;
	}

716
	if (strcmp(sb->s_type->name, "proc") == 0)
717
		sbsec->flags |= SE_SBPROC;
718

719 720 721 722 723
	if (!sbsec->behavior) {
		/*
		 * Determine the labeling behavior to use for this
		 * filesystem type.
		 */
724
		rc = security_fs_use(sb);
725 726 727 728 729 730
		if (rc) {
			printk(KERN_WARNING
				"%s: security_fs_use(%s) returned %d\n",
					__func__, sb->s_type->name, rc);
			goto out;
		}
731 732 733
	}
	/* sets the context of the superblock for the fs being mounted. */
	if (fscontext_sid) {
734
		rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
L
Linus Torvalds 已提交
735
		if (rc)
736
			goto out;
L
Linus Torvalds 已提交
737

738
		sbsec->sid = fscontext_sid;
739 740 741 742 743 744 745
	}

	/*
	 * 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.
	 */
746 747 748 749 750
	if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) {
		sbsec->behavior = SECURITY_FS_USE_NATIVE;
		*set_kern_flags |= SECURITY_LSM_NATIVE_LABELS;
	}

751 752
	if (context_sid) {
		if (!fscontext_sid) {
753 754
			rc = may_context_mount_sb_relabel(context_sid, sbsec,
							  cred);
755
			if (rc)
756 757
				goto out;
			sbsec->sid = context_sid;
758
		} else {
759 760
			rc = may_context_mount_inode_relabel(context_sid, sbsec,
							     cred);
761
			if (rc)
762
				goto out;
763
		}
764 765
		if (!rootcontext_sid)
			rootcontext_sid = context_sid;
L
Linus Torvalds 已提交
766

767
		sbsec->mntpoint_sid = context_sid;
768
		sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
L
Linus Torvalds 已提交
769 770
	}

771
	if (rootcontext_sid) {
772 773
		rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
						     cred);
774
		if (rc)
775
			goto out;
776

777 778
		root_isec->sid = rootcontext_sid;
		root_isec->initialized = 1;
779 780
	}

781
	if (defcontext_sid) {
782 783
		if (sbsec->behavior != SECURITY_FS_USE_XATTR &&
			sbsec->behavior != SECURITY_FS_USE_NATIVE) {
784 785 786 787
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux: defcontext option is "
			       "invalid for this filesystem type\n");
			goto out;
L
Linus Torvalds 已提交
788 789
		}

790 791
		if (defcontext_sid != sbsec->def_sid) {
			rc = may_context_mount_inode_relabel(defcontext_sid,
792
							     sbsec, cred);
793 794 795
			if (rc)
				goto out;
		}
L
Linus Torvalds 已提交
796

797
		sbsec->def_sid = defcontext_sid;
L
Linus Torvalds 已提交
798 799
	}

800
	rc = sb_finish_set_opts(sb);
L
Linus Torvalds 已提交
801
out:
802
	mutex_unlock(&sbsec->lock);
L
Linus Torvalds 已提交
803
	return rc;
804 805 806
out_double_mount:
	rc = -EINVAL;
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
807
	       "security settings for (dev %s, type %s)\n", sb->s_id, name);
808
	goto out;
L
Linus Torvalds 已提交
809 810
}

811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841
static int selinux_cmp_sb_context(const struct super_block *oldsb,
				    const struct super_block *newsb)
{
	struct superblock_security_struct *old = oldsb->s_security;
	struct superblock_security_struct *new = newsb->s_security;
	char oldflags = old->flags & SE_MNTMASK;
	char newflags = new->flags & SE_MNTMASK;

	if (oldflags != newflags)
		goto mismatch;
	if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
		goto mismatch;
	if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
		goto mismatch;
	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
		goto mismatch;
	if (oldflags & ROOTCONTEXT_MNT) {
		struct inode_security_struct *oldroot = oldsb->s_root->d_inode->i_security;
		struct inode_security_struct *newroot = newsb->s_root->d_inode->i_security;
		if (oldroot->sid != newroot->sid)
			goto mismatch;
	}
	return 0;
mismatch:
	printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, "
			    "different security settings for (dev %s, "
			    "type %s)\n", newsb->s_id, newsb->s_type->name);
	return -EBUSY;
}

static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
842
					struct super_block *newsb)
L
Linus Torvalds 已提交
843
{
844 845
	const struct superblock_security_struct *oldsbsec = oldsb->s_security;
	struct superblock_security_struct *newsbsec = newsb->s_security;
L
Linus Torvalds 已提交
846

847 848 849
	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
850

851 852
	/*
	 * if the parent was able to be mounted it clearly had no special lsm
853
	 * mount options.  thus we can safely deal with this superblock later
854
	 */
855
	if (!ss_initialized)
856
		return 0;
857 858

	/* how can we clone if the old one wasn't set up?? */
859
	BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
860

861
	/* if fs is reusing a sb, make sure that the contexts match */
862
	if (newsbsec->flags & SE_SBINITIALIZED)
863
		return selinux_cmp_sb_context(oldsb, newsb);
864

865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883
	mutex_lock(&newsbsec->lock);

	newsbsec->flags = oldsbsec->flags;

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

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

		if (!set_fscontext)
			newsbsec->sid = sid;
		if (!set_rootcontext) {
			struct inode *newinode = newsb->s_root->d_inode;
			struct inode_security_struct *newisec = newinode->i_security;
			newisec->sid = sid;
		}
		newsbsec->mntpoint_sid = sid;
L
Linus Torvalds 已提交
884
	}
885 886 887 888 889
	if (set_rootcontext) {
		const struct inode *oldinode = oldsb->s_root->d_inode;
		const struct inode_security_struct *oldisec = oldinode->i_security;
		struct inode *newinode = newsb->s_root->d_inode;
		struct inode_security_struct *newisec = newinode->i_security;
L
Linus Torvalds 已提交
890

891
		newisec->sid = oldisec->sid;
L
Linus Torvalds 已提交
892 893
	}

894 895
	sb_finish_set_opts(newsb);
	mutex_unlock(&newsbsec->lock);
896
	return 0;
897 898
}

899 900
static int selinux_parse_opts_str(char *options,
				  struct security_mnt_opts *opts)
901
{
902
	char *p;
903 904
	char *context = NULL, *defcontext = NULL;
	char *fscontext = NULL, *rootcontext = NULL;
905
	int rc, num_mnt_opts = 0;
L
Linus Torvalds 已提交
906

907
	opts->num_mnt_opts = 0;
L
Linus Torvalds 已提交
908

909 910 911 912
	/* Standard string-based options. */
	while ((p = strsep(&options, "|")) != NULL) {
		int token;
		substring_t args[MAX_OPT_ARGS];
L
Linus Torvalds 已提交
913

914 915
		if (!*p)
			continue;
L
Linus Torvalds 已提交
916

917
		token = match_token(p, tokens, args);
L
Linus Torvalds 已提交
918

919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970
		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;
971 972
		case Opt_labelsupport:
			break;
973 974 975 976
		default:
			rc = -EINVAL;
			printk(KERN_WARNING "SELinux:  unknown mount option\n");
			goto out_err;
L
Linus Torvalds 已提交
977 978 979

		}
	}
980

981 982 983 984 985 986 987 988 989 990 991
	rc = -ENOMEM;
	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
	if (!opts->mnt_opts)
		goto out_err;

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

992
	if (fscontext) {
993 994
		opts->mnt_opts[num_mnt_opts] = fscontext;
		opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
995 996
	}
	if (context) {
997 998
		opts->mnt_opts[num_mnt_opts] = context;
		opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
999 1000
	}
	if (rootcontext) {
1001 1002
		opts->mnt_opts[num_mnt_opts] = rootcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
1003 1004
	}
	if (defcontext) {
1005 1006
		opts->mnt_opts[num_mnt_opts] = defcontext;
		opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
1007 1008
	}

1009 1010 1011
	opts->num_mnt_opts = num_mnt_opts;
	return 0;

1012 1013 1014 1015 1016
out_err:
	kfree(context);
	kfree(defcontext);
	kfree(fscontext);
	kfree(rootcontext);
L
Linus Torvalds 已提交
1017 1018
	return rc;
}
1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039
/*
 * 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:
1040
	rc = selinux_set_mnt_opts(sb, &opts, 0, NULL);
1041 1042 1043 1044 1045

out_err:
	security_free_mnt_opts(&opts);
	return rc;
}
L
Linus Torvalds 已提交
1046

A
Adrian Bunk 已提交
1047 1048
static void selinux_write_opts(struct seq_file *m,
			       struct security_mnt_opts *opts)
1049 1050 1051 1052 1053
{
	int i;
	char *prefix;

	for (i = 0; i < opts->num_mnt_opts; i++) {
1054 1055 1056 1057 1058 1059
		char *has_comma;

		if (opts->mnt_opts[i])
			has_comma = strchr(opts->mnt_opts[i], ',');
		else
			has_comma = NULL;
1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073

		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;
1074
		case SBLABEL_MNT:
1075 1076 1077
			seq_putc(m, ',');
			seq_puts(m, LABELSUPP_STR);
			continue;
1078 1079
		default:
			BUG();
1080
			return;
1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098
		};
		/* we need a comma before each option */
		seq_putc(m, ',');
		seq_puts(m, prefix);
		if (has_comma)
			seq_putc(m, '\"');
		seq_puts(m, opts->mnt_opts[i]);
		if (has_comma)
			seq_putc(m, '\"');
	}
}

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

	rc = selinux_get_mnt_opts(sb, &opts);
1099 1100 1101 1102
	if (rc) {
		/* before policy load we may get EINVAL, don't show anything */
		if (rc == -EINVAL)
			rc = 0;
1103
		return rc;
1104
	}
1105 1106 1107 1108 1109 1110 1111 1112

	selinux_write_opts(m, &opts);

	security_free_mnt_opts(&opts);

	return rc;
}

L
Linus Torvalds 已提交
1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135
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;
}

1136 1137 1138 1139 1140 1141 1142 1143 1144 1145
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
1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161
static inline u16 socket_type_to_security_class(int family, int type, int protocol)
{
	switch (family) {
	case PF_UNIX:
		switch (type) {
		case SOCK_STREAM:
		case SOCK_SEQPACKET:
			return SECCLASS_UNIX_STREAM_SOCKET;
		case SOCK_DGRAM:
			return SECCLASS_UNIX_DGRAM_SOCKET;
		}
		break;
	case PF_INET:
	case PF_INET6:
		switch (type) {
		case SOCK_STREAM:
1162 1163 1164 1165
			if (default_protocol_stream(protocol))
				return SECCLASS_TCP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
L
Linus Torvalds 已提交
1166
		case SOCK_DGRAM:
1167 1168 1169 1170
			if (default_protocol_dgram(protocol))
				return SECCLASS_UDP_SOCKET;
			else
				return SECCLASS_RAWIP_SOCKET;
J
James Morris 已提交
1171 1172
		case SOCK_DCCP:
			return SECCLASS_DCCP_SOCKET;
1173
		default:
L
Linus Torvalds 已提交
1174 1175 1176 1177 1178 1179 1180 1181 1182
			return SECCLASS_RAWIP_SOCKET;
		}
		break;
	case PF_NETLINK:
		switch (protocol) {
		case NETLINK_ROUTE:
			return SECCLASS_NETLINK_ROUTE_SOCKET;
		case NETLINK_FIREWALL:
			return SECCLASS_NETLINK_FIREWALL_SOCKET;
1183
		case NETLINK_SOCK_DIAG:
L
Linus Torvalds 已提交
1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196
			return SECCLASS_NETLINK_TCPDIAG_SOCKET;
		case NETLINK_NFLOG:
			return SECCLASS_NETLINK_NFLOG_SOCKET;
		case NETLINK_XFRM:
			return SECCLASS_NETLINK_XFRM_SOCKET;
		case NETLINK_SELINUX:
			return SECCLASS_NETLINK_SELINUX_SOCKET;
		case NETLINK_AUDIT:
			return SECCLASS_NETLINK_AUDIT_SOCKET;
		case NETLINK_IP6_FW:
			return SECCLASS_NETLINK_IP6FW_SOCKET;
		case NETLINK_DNRTMSG:
			return SECCLASS_NETLINK_DNRT_SOCKET;
1197 1198
		case NETLINK_KOBJECT_UEVENT:
			return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
L
Linus Torvalds 已提交
1199 1200 1201 1202 1203 1204 1205
		default:
			return SECCLASS_NETLINK_SOCKET;
		}
	case PF_PACKET:
		return SECCLASS_PACKET_SOCKET;
	case PF_KEY:
		return SECCLASS_KEY_SOCKET;
1206 1207
	case PF_APPLETALK:
		return SECCLASS_APPLETALK_SOCKET;
L
Linus Torvalds 已提交
1208 1209 1210 1211 1212 1213
	}

	return SECCLASS_SOCKET;
}

#ifdef CONFIG_PROC_FS
1214
static int selinux_proc_get_sid(struct dentry *dentry,
L
Linus Torvalds 已提交
1215 1216 1217
				u16 tclass,
				u32 *sid)
{
1218 1219
	int rc;
	char *buffer, *path;
L
Linus Torvalds 已提交
1220

1221
	buffer = (char *)__get_free_page(GFP_KERNEL);
L
Linus Torvalds 已提交
1222 1223 1224
	if (!buffer)
		return -ENOMEM;

1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236
	path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
	if (IS_ERR(path))
		rc = PTR_ERR(path);
	else {
		/* each process gets a /proc/PID/ entry. Strip off the
		 * PID part to get a valid selinux labeling.
		 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
		while (path[1] >= '0' && path[1] <= '9') {
			path[1] = '/';
			path++;
		}
		rc = security_genfs_sid("proc", path, tclass, sid);
L
Linus Torvalds 已提交
1237 1238 1239 1240 1241
	}
	free_page((unsigned long)buffer);
	return rc;
}
#else
1242
static int selinux_proc_get_sid(struct dentry *dentry,
L
Linus Torvalds 已提交
1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264
				u16 tclass,
				u32 *sid)
{
	return -EINVAL;
}
#endif

/* The inode's security attributes must be initialized before first use. */
static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
{
	struct superblock_security_struct *sbsec = NULL;
	struct inode_security_struct *isec = inode->i_security;
	u32 sid;
	struct dentry *dentry;
#define INITCONTEXTLEN 255
	char *context = NULL;
	unsigned len = 0;
	int rc = 0;

	if (isec->initialized)
		goto out;

1265
	mutex_lock(&isec->lock);
L
Linus Torvalds 已提交
1266
	if (isec->initialized)
1267
		goto out_unlock;
L
Linus Torvalds 已提交
1268 1269

	sbsec = inode->i_sb->s_security;
1270
	if (!(sbsec->flags & SE_SBINITIALIZED)) {
L
Linus Torvalds 已提交
1271 1272 1273 1274 1275 1276 1277
		/* 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);
1278
		goto out_unlock;
L
Linus Torvalds 已提交
1279 1280 1281
	}

	switch (sbsec->behavior) {
1282 1283
	case SECURITY_FS_USE_NATIVE:
		break;
L
Linus Torvalds 已提交
1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299
	case SECURITY_FS_USE_XATTR:
		if (!inode->i_op->getxattr) {
			isec->sid = sbsec->def_sid;
			break;
		}

		/* Need a dentry, since the xattr API requires one.
		   Life would be simpler if we could just pass the inode. */
		if (opt_dentry) {
			/* Called from d_instantiate or d_splice_alias. */
			dentry = dget(opt_dentry);
		} else {
			/* Called from selinux_complete_init, try to find a dentry. */
			dentry = d_find_alias(inode);
		}
		if (!dentry) {
1300 1301 1302 1303 1304 1305 1306 1307 1308
			/*
			 * 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.
			 */
1309
			goto out_unlock;
L
Linus Torvalds 已提交
1310 1311 1312
		}

		len = INITCONTEXTLEN;
1313
		context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1314 1315 1316
		if (!context) {
			rc = -ENOMEM;
			dput(dentry);
1317
			goto out_unlock;
L
Linus Torvalds 已提交
1318
		}
1319
		context[len] = '\0';
L
Linus Torvalds 已提交
1320 1321 1322
		rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
					   context, len);
		if (rc == -ERANGE) {
1323 1324
			kfree(context);

L
Linus Torvalds 已提交
1325 1326 1327 1328 1329
			/* Need a larger buffer.  Query for the right size. */
			rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
						   NULL, 0);
			if (rc < 0) {
				dput(dentry);
1330
				goto out_unlock;
L
Linus Torvalds 已提交
1331 1332
			}
			len = rc;
1333
			context = kmalloc(len+1, GFP_NOFS);
L
Linus Torvalds 已提交
1334 1335 1336
			if (!context) {
				rc = -ENOMEM;
				dput(dentry);
1337
				goto out_unlock;
L
Linus Torvalds 已提交
1338
			}
1339
			context[len] = '\0';
L
Linus Torvalds 已提交
1340 1341 1342 1343 1344 1345 1346
			rc = inode->i_op->getxattr(dentry,
						   XATTR_NAME_SELINUX,
						   context, len);
		}
		dput(dentry);
		if (rc < 0) {
			if (rc != -ENODATA) {
E
Eric Paris 已提交
1347
				printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1348
				       "%d for dev=%s ino=%ld\n", __func__,
L
Linus Torvalds 已提交
1349 1350
				       -rc, inode->i_sb->s_id, inode->i_ino);
				kfree(context);
1351
				goto out_unlock;
L
Linus Torvalds 已提交
1352 1353 1354 1355 1356
			}
			/* Map ENODATA to the default file SID */
			sid = sbsec->def_sid;
			rc = 0;
		} else {
1357
			rc = security_context_to_sid_default(context, rc, &sid,
1358 1359
							     sbsec->def_sid,
							     GFP_NOFS);
L
Linus Torvalds 已提交
1360
			if (rc) {
1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373
				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
1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391
				kfree(context);
				/* Leave with the unlabeled SID */
				rc = 0;
				break;
			}
		}
		kfree(context);
		isec->sid = sid;
		break;
	case SECURITY_FS_USE_TASK:
		isec->sid = isec->task_sid;
		break;
	case SECURITY_FS_USE_TRANS:
		/* Default to the fs SID. */
		isec->sid = sbsec->sid;

		/* Try to obtain a transition SID. */
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
1392 1393
		rc = security_transition_sid(isec->task_sid, sbsec->sid,
					     isec->sclass, NULL, &sid);
L
Linus Torvalds 已提交
1394
		if (rc)
1395
			goto out_unlock;
L
Linus Torvalds 已提交
1396 1397
		isec->sid = sid;
		break;
1398 1399 1400
	case SECURITY_FS_USE_MNTPOINT:
		isec->sid = sbsec->mntpoint_sid;
		break;
L
Linus Torvalds 已提交
1401
	default:
1402
		/* Default to the fs superblock SID. */
L
Linus Torvalds 已提交
1403 1404
		isec->sid = sbsec->sid;

1405
		if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1406
			if (opt_dentry) {
L
Linus Torvalds 已提交
1407
				isec->sclass = inode_mode_to_security_class(inode->i_mode);
1408
				rc = selinux_proc_get_sid(opt_dentry,
L
Linus Torvalds 已提交
1409 1410 1411
							  isec->sclass,
							  &sid);
				if (rc)
1412
					goto out_unlock;
L
Linus Torvalds 已提交
1413 1414 1415 1416 1417 1418 1419 1420
				isec->sid = sid;
			}
		}
		break;
	}

	isec->initialized = 1;

1421 1422
out_unlock:
	mutex_unlock(&isec->lock);
L
Linus Torvalds 已提交
1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455
out:
	if (isec->sclass == SECCLASS_FILE)
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
	return rc;
}

/* Convert a Linux signal to an access vector. */
static inline u32 signal_to_av(int sig)
{
	u32 perm = 0;

	switch (sig) {
	case SIGCHLD:
		/* Commonly granted from child to parent. */
		perm = PROCESS__SIGCHLD;
		break;
	case SIGKILL:
		/* Cannot be caught or ignored */
		perm = PROCESS__SIGKILL;
		break;
	case SIGSTOP:
		/* Cannot be caught or ignored */
		perm = PROCESS__SIGSTOP;
		break;
	default:
		/* All other signals. */
		perm = PROCESS__SIGNAL;
		break;
	}

	return perm;
}

D
David Howells 已提交
1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468
/*
 * Check permission between a pair of credentials
 * fork check, ptrace check, etc.
 */
static int cred_has_perm(const struct cred *actor,
			 const struct cred *target,
			 u32 perms)
{
	u32 asid = cred_sid(actor), tsid = cred_sid(target);

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

1469
/*
1470
 * Check permission between a pair of tasks, e.g. signal checks,
1471 1472
 * fork check, ptrace check, etc.
 * tsk1 is the actor and tsk2 is the target
1473
 * - this uses the default subjective creds of tsk1
1474 1475 1476
 */
static int task_has_perm(const struct task_struct *tsk1,
			 const struct task_struct *tsk2,
L
Linus Torvalds 已提交
1477 1478
			 u32 perms)
{
1479 1480
	const struct task_security_struct *__tsec1, *__tsec2;
	u32 sid1, sid2;
L
Linus Torvalds 已提交
1481

1482 1483 1484 1485 1486
	rcu_read_lock();
	__tsec1 = __task_cred(tsk1)->security;	sid1 = __tsec1->sid;
	__tsec2 = __task_cred(tsk2)->security;	sid2 = __tsec2->sid;
	rcu_read_unlock();
	return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
L
Linus Torvalds 已提交
1487 1488
}

1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504
/*
 * Check permission between current and another task, e.g. signal checks,
 * fork check, ptrace check, etc.
 * current is the actor and tsk2 is the target
 * - this uses current's subjective creds
 */
static int current_has_perm(const struct task_struct *tsk,
			    u32 perms)
{
	u32 sid, tsid;

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

1505 1506 1507 1508
#if CAP_LAST_CAP > 63
#error Fix SELinux to handle capabilities > 63.
#endif

L
Linus Torvalds 已提交
1509
/* Check whether a task is allowed to use a capability. */
1510
static int cred_has_capability(const struct cred *cred,
1511
			       int cap, int audit)
L
Linus Torvalds 已提交
1512
{
1513
	struct common_audit_data ad;
1514
	struct av_decision avd;
1515
	u16 sclass;
1516
	u32 sid = cred_sid(cred);
1517
	u32 av = CAP_TO_MASK(cap);
1518
	int rc;
L
Linus Torvalds 已提交
1519

1520
	ad.type = LSM_AUDIT_DATA_CAP;
L
Linus Torvalds 已提交
1521 1522
	ad.u.cap = cap;

1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533
	switch (CAP_TO_INDEX(cap)) {
	case 0:
		sclass = SECCLASS_CAPABILITY;
		break;
	case 1:
		sclass = SECCLASS_CAPABILITY2;
		break;
	default:
		printk(KERN_ERR
		       "SELinux:  out of range capability %d\n", cap);
		BUG();
1534
		return -EINVAL;
1535
	}
1536

1537
	rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1538
	if (audit == SECURITY_CAP_AUDIT) {
1539
		int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1540 1541 1542
		if (rc2)
			return rc2;
	}
1543
	return rc;
L
Linus Torvalds 已提交
1544 1545 1546 1547 1548 1549
}

/* Check whether a task is allowed to use a system operation. */
static int task_has_system(struct task_struct *tsk,
			   u32 perms)
{
1550
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
1551

1552
	return avc_has_perm(sid, SECINITSID_KERNEL,
L
Linus Torvalds 已提交
1553 1554 1555 1556 1557 1558
			    SECCLASS_SYSTEM, perms, NULL);
}

/* Check whether a task has a particular permission to an inode.
   The 'adp' parameter is optional and allows other audit
   data to be passed (e.g. the dentry). */
1559
static int inode_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1560 1561
			  struct inode *inode,
			  u32 perms,
1562
			  struct common_audit_data *adp)
L
Linus Torvalds 已提交
1563 1564
{
	struct inode_security_struct *isec;
1565
	u32 sid;
L
Linus Torvalds 已提交
1566

1567 1568
	validate_creds(cred);

1569
	if (unlikely(IS_PRIVATE(inode)))
1570 1571
		return 0;

1572
	sid = cred_sid(cred);
L
Linus Torvalds 已提交
1573 1574
	isec = inode->i_security;

1575
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
L
Linus Torvalds 已提交
1576 1577 1578 1579 1580
}

/* 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. */
1581
static inline int dentry_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1582 1583 1584 1585
				  struct dentry *dentry,
				  u32 av)
{
	struct inode *inode = dentry->d_inode;
1586
	struct common_audit_data ad;
1587

1588
	ad.type = LSM_AUDIT_DATA_DENTRY;
E
Eric Paris 已提交
1589
	ad.u.dentry = dentry;
1590
	return inode_has_perm(cred, inode, av, &ad);
E
Eric Paris 已提交
1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602
}

/* Same as inode_has_perm, but pass explicit audit data containing
   the path to help the auditing code to more easily generate the
   pathname if needed. */
static inline int path_has_perm(const struct cred *cred,
				struct path *path,
				u32 av)
{
	struct inode *inode = path->dentry->d_inode;
	struct common_audit_data ad;

1603
	ad.type = LSM_AUDIT_DATA_PATH;
E
Eric Paris 已提交
1604
	ad.u.path = *path;
1605
	return inode_has_perm(cred, inode, av, &ad);
L
Linus Torvalds 已提交
1606 1607
}

1608 1609 1610 1611 1612 1613 1614 1615 1616
/* 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;

	ad.type = LSM_AUDIT_DATA_PATH;
	ad.u.path = file->f_path;
1617
	return inode_has_perm(cred, file_inode(file), av, &ad);
1618 1619
}

L
Linus Torvalds 已提交
1620 1621 1622 1623 1624 1625 1626 1627
/* 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. */
1628 1629 1630
static int file_has_perm(const struct cred *cred,
			 struct file *file,
			 u32 av)
L
Linus Torvalds 已提交
1631 1632
{
	struct file_security_struct *fsec = file->f_security;
A
Al Viro 已提交
1633
	struct inode *inode = file_inode(file);
1634
	struct common_audit_data ad;
1635
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1636 1637
	int rc;

1638
	ad.type = LSM_AUDIT_DATA_PATH;
1639
	ad.u.path = file->f_path;
L
Linus Torvalds 已提交
1640

1641 1642
	if (sid != fsec->sid) {
		rc = avc_has_perm(sid, fsec->sid,
L
Linus Torvalds 已提交
1643 1644 1645 1646
				  SECCLASS_FD,
				  FD__USE,
				  &ad);
		if (rc)
1647
			goto out;
L
Linus Torvalds 已提交
1648 1649 1650
	}

	/* av is zero if only checking access to the descriptor. */
1651
	rc = 0;
L
Linus Torvalds 已提交
1652
	if (av)
1653
		rc = inode_has_perm(cred, inode, av, &ad);
L
Linus Torvalds 已提交
1654

1655 1656
out:
	return rc;
L
Linus Torvalds 已提交
1657 1658 1659 1660 1661 1662 1663
}

/* Check whether a task can create a file. */
static int may_create(struct inode *dir,
		      struct dentry *dentry,
		      u16 tclass)
{
1664
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
1665 1666
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
1667
	u32 sid, newsid;
1668
	struct common_audit_data ad;
L
Linus Torvalds 已提交
1669 1670 1671 1672 1673
	int rc;

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

1674 1675 1676
	sid = tsec->sid;
	newsid = tsec->create_sid;

1677
	ad.type = LSM_AUDIT_DATA_DENTRY;
1678
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1679

1680
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1681 1682 1683 1684 1685
			  DIR__ADD_NAME | DIR__SEARCH,
			  &ad);
	if (rc)
		return rc;

1686
	if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
1687 1688
		rc = security_transition_sid(sid, dsec->sid, tclass,
					     &dentry->d_name, &newsid);
L
Linus Torvalds 已提交
1689 1690 1691 1692
		if (rc)
			return rc;
	}

1693
	rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
L
Linus Torvalds 已提交
1694 1695 1696 1697 1698 1699 1700 1701
	if (rc)
		return rc;

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

1702 1703 1704 1705
/* Check whether a task can create a key. */
static int may_create_key(u32 ksid,
			  struct task_struct *ctx)
{
1706
	u32 sid = task_sid(ctx);
1707

1708
	return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1709 1710
}

1711 1712 1713
#define MAY_LINK	0
#define MAY_UNLINK	1
#define MAY_RMDIR	2
L
Linus Torvalds 已提交
1714 1715 1716 1717 1718 1719 1720 1721

/* 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;
1722
	struct common_audit_data ad;
1723
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1724 1725 1726 1727 1728 1729
	u32 av;
	int rc;

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

1730
	ad.type = LSM_AUDIT_DATA_DENTRY;
1731
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
1732 1733 1734

	av = DIR__SEARCH;
	av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1735
	rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749
	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
1750 1751
		printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
			__func__, kind);
L
Linus Torvalds 已提交
1752 1753 1754
		return 0;
	}

1755
	rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
L
Linus Torvalds 已提交
1756 1757 1758 1759 1760 1761 1762 1763 1764
	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;
1765
	struct common_audit_data ad;
1766
	u32 sid = current_sid();
L
Linus Torvalds 已提交
1767 1768 1769 1770 1771 1772 1773 1774 1775
	u32 av;
	int old_is_dir, new_is_dir;
	int rc;

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

1776
	ad.type = LSM_AUDIT_DATA_DENTRY;
L
Linus Torvalds 已提交
1777

1778
	ad.u.dentry = old_dentry;
1779
	rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
L
Linus Torvalds 已提交
1780 1781 1782
			  DIR__REMOVE_NAME | DIR__SEARCH, &ad);
	if (rc)
		return rc;
1783
	rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1784 1785 1786 1787
			  old_isec->sclass, FILE__RENAME, &ad);
	if (rc)
		return rc;
	if (old_is_dir && new_dir != old_dir) {
1788
		rc = avc_has_perm(sid, old_isec->sid,
L
Linus Torvalds 已提交
1789 1790 1791 1792 1793
				  old_isec->sclass, DIR__REPARENT, &ad);
		if (rc)
			return rc;
	}

1794
	ad.u.dentry = new_dentry;
L
Linus Torvalds 已提交
1795 1796 1797
	av = DIR__ADD_NAME | DIR__SEARCH;
	if (new_dentry->d_inode)
		av |= DIR__REMOVE_NAME;
1798
	rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
L
Linus Torvalds 已提交
1799 1800 1801 1802 1803
	if (rc)
		return rc;
	if (new_dentry->d_inode) {
		new_isec = new_dentry->d_inode->i_security;
		new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1804
		rc = avc_has_perm(sid, new_isec->sid,
L
Linus Torvalds 已提交
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814
				  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. */
1815
static int superblock_has_perm(const struct cred *cred,
L
Linus Torvalds 已提交
1816 1817
			       struct super_block *sb,
			       u32 perms,
1818
			       struct common_audit_data *ad)
L
Linus Torvalds 已提交
1819 1820
{
	struct superblock_security_struct *sbsec;
1821
	u32 sid = cred_sid(cred);
L
Linus Torvalds 已提交
1822 1823

	sbsec = sb->s_security;
1824
	return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
L
Linus Torvalds 已提交
1825 1826 1827 1828 1829 1830 1831
}

/* 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
1832
	if (!S_ISDIR(mode)) {
L
Linus Torvalds 已提交
1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854
		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;
}

1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877
/* 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
1878
/*
1879
 * Convert a file to an access vector and include the correct open
E
Eric Paris 已提交
1880 1881
 * open permission.
 */
1882
static inline u32 open_file_to_av(struct file *file)
E
Eric Paris 已提交
1883
{
1884
	u32 av = file_to_av(file);
E
Eric Paris 已提交
1885

1886 1887 1888
	if (selinux_policycap_openperm)
		av |= FILE__OPEN;

E
Eric Paris 已提交
1889 1890 1891
	return av;
}

L
Linus Torvalds 已提交
1892 1893
/* Hook functions begin here. */

1894
static int selinux_ptrace_access_check(struct task_struct *child,
1895
				     unsigned int mode)
L
Linus Torvalds 已提交
1896 1897 1898
{
	int rc;

1899
	rc = cap_ptrace_access_check(child, mode);
L
Linus Torvalds 已提交
1900 1901 1902
	if (rc)
		return rc;

1903
	if (mode & PTRACE_MODE_READ) {
1904 1905 1906
		u32 sid = current_sid();
		u32 csid = task_sid(child);
		return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1907 1908
	}

1909
	return current_has_perm(child, PROCESS__PTRACE);
1910 1911 1912 1913 1914 1915
}

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

1916
	rc = cap_ptrace_traceme(parent);
1917 1918 1919 1920
	if (rc)
		return rc;

	return task_has_perm(parent, current, PROCESS__PTRACE);
L
Linus Torvalds 已提交
1921 1922 1923
}

static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1924
			  kernel_cap_t *inheritable, kernel_cap_t *permitted)
L
Linus Torvalds 已提交
1925 1926 1927
{
	int error;

1928
	error = current_has_perm(target, PROCESS__GETCAP);
L
Linus Torvalds 已提交
1929 1930 1931
	if (error)
		return error;

1932
	return cap_capget(target, effective, inheritable, permitted);
L
Linus Torvalds 已提交
1933 1934
}

D
David Howells 已提交
1935 1936 1937 1938
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
1939 1940 1941
{
	int error;

1942
	error = cap_capset(new, old,
D
David Howells 已提交
1943
				      effective, inheritable, permitted);
L
Linus Torvalds 已提交
1944 1945 1946
	if (error)
		return error;

D
David Howells 已提交
1947
	return cred_has_perm(old, new, PROCESS__SETCAP);
L
Linus Torvalds 已提交
1948 1949
}

1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
/*
 * (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.
 */

1960 1961
static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
			   int cap, int audit)
L
Linus Torvalds 已提交
1962 1963 1964
{
	int rc;

1965
	rc = cap_capable(cred, ns, cap, audit);
L
Linus Torvalds 已提交
1966 1967 1968
	if (rc)
		return rc;

1969
	return cred_has_capability(cred, cap, audit);
L
Linus Torvalds 已提交
1970 1971 1972 1973
}

static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
{
1974
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
1975 1976 1977 1978 1979 1980
	int rc = 0;

	if (!sb)
		return 0;

	switch (cmds) {
1981 1982 1983 1984 1985
	case Q_SYNC:
	case Q_QUOTAON:
	case Q_QUOTAOFF:
	case Q_SETINFO:
	case Q_SETQUOTA:
1986
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1987 1988 1989 1990
		break;
	case Q_GETFMT:
	case Q_GETINFO:
	case Q_GETQUOTA:
1991
		rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1992 1993 1994 1995
		break;
	default:
		rc = 0;  /* let the kernel handle invalid cmds */
		break;
L
Linus Torvalds 已提交
1996 1997 1998 1999 2000 2001
	}
	return rc;
}

static int selinux_quota_on(struct dentry *dentry)
{
2002 2003
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2004
	return dentry_has_perm(cred, dentry, FILE__QUOTAON);
L
Linus Torvalds 已提交
2005 2006
}

2007
static int selinux_syslog(int type)
L
Linus Torvalds 已提交
2008 2009 2010 2011
{
	int rc;

	switch (type) {
2012 2013
	case SYSLOG_ACTION_READ_ALL:	/* Read last kernel messages */
	case SYSLOG_ACTION_SIZE_BUFFER:	/* Return size of the log buffer */
2014 2015
		rc = task_has_system(current, SYSTEM__SYSLOG_READ);
		break;
2016 2017 2018 2019
	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:
2020 2021
		rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
		break;
2022 2023 2024 2025 2026
	case SYSLOG_ACTION_CLOSE:	/* Close log */
	case SYSLOG_ACTION_OPEN:	/* Open log */
	case SYSLOG_ACTION_READ:	/* Read from log */
	case SYSLOG_ACTION_READ_CLEAR:	/* Read/clear last kernel messages */
	case SYSLOG_ACTION_CLEAR:	/* Clear ring buffer */
2027 2028 2029
	default:
		rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
		break;
L
Linus Torvalds 已提交
2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041
	}
	return rc;
}

/*
 * Check that a process has enough memory to allocate a new virtual
 * mapping. 0 means there is enough memory for the allocation to
 * succeed and -ENOMEM implies there is not.
 *
 * Do not audit the selinux permission check, as this is applied to all
 * processes that allocate mappings.
 */
2042
static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
L
Linus Torvalds 已提交
2043 2044 2045
{
	int rc, cap_sys_admin = 0;

2046
	rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
2047
			     SECURITY_CAP_NOAUDIT);
L
Linus Torvalds 已提交
2048 2049 2050
	if (rc == 0)
		cap_sys_admin = 1;

2051
	return __vm_enough_memory(mm, pages, cap_sys_admin);
L
Linus Torvalds 已提交
2052 2053 2054 2055
}

/* binprm security operations */

2056
static int selinux_bprm_set_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2057
{
2058 2059
	const struct task_security_struct *old_tsec;
	struct task_security_struct *new_tsec;
L
Linus Torvalds 已提交
2060
	struct inode_security_struct *isec;
2061
	struct common_audit_data ad;
A
Al Viro 已提交
2062
	struct inode *inode = file_inode(bprm->file);
L
Linus Torvalds 已提交
2063 2064
	int rc;

2065
	rc = cap_bprm_set_creds(bprm);
L
Linus Torvalds 已提交
2066 2067 2068
	if (rc)
		return rc;

2069 2070 2071
	/* SELinux context only depends on initial program or script and not
	 * the script interpreter */
	if (bprm->cred_prepared)
L
Linus Torvalds 已提交
2072 2073
		return 0;

2074 2075
	old_tsec = current_security();
	new_tsec = bprm->cred->security;
L
Linus Torvalds 已提交
2076 2077 2078
	isec = inode->i_security;

	/* Default to the current task SID. */
2079 2080
	new_tsec->sid = old_tsec->sid;
	new_tsec->osid = old_tsec->sid;
L
Linus Torvalds 已提交
2081

2082
	/* Reset fs, key, and sock SIDs on execve. */
2083 2084 2085
	new_tsec->create_sid = 0;
	new_tsec->keycreate_sid = 0;
	new_tsec->sockcreate_sid = 0;
L
Linus Torvalds 已提交
2086

2087 2088
	if (old_tsec->exec_sid) {
		new_tsec->sid = old_tsec->exec_sid;
L
Linus Torvalds 已提交
2089
		/* Reset exec SID on execve. */
2090
		new_tsec->exec_sid = 0;
2091 2092 2093 2094 2095 2096 2097

		/*
		 * Minimize confusion: if no_new_privs and a transition is
		 * explicitly requested, then fail the exec.
		 */
		if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
			return -EPERM;
L
Linus Torvalds 已提交
2098 2099
	} else {
		/* Check for a default transition on this program. */
2100
		rc = security_transition_sid(old_tsec->sid, isec->sid,
2101 2102
					     SECCLASS_PROCESS, NULL,
					     &new_tsec->sid);
L
Linus Torvalds 已提交
2103 2104 2105 2106
		if (rc)
			return rc;
	}

2107
	ad.type = LSM_AUDIT_DATA_PATH;
2108
	ad.u.path = bprm->file->f_path;
L
Linus Torvalds 已提交
2109

2110 2111
	if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) ||
	    (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS))
2112
		new_tsec->sid = old_tsec->sid;
L
Linus Torvalds 已提交
2113

2114 2115
	if (new_tsec->sid == old_tsec->sid) {
		rc = avc_has_perm(old_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2116 2117 2118 2119 2120
				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
		if (rc)
			return rc;
	} else {
		/* Check permissions for the transition. */
2121
		rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
L
Linus Torvalds 已提交
2122 2123 2124 2125
				  SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
		if (rc)
			return rc;

2126
		rc = avc_has_perm(new_tsec->sid, isec->sid,
L
Linus Torvalds 已提交
2127 2128 2129 2130
				  SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
		if (rc)
			return rc;

2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148
		/* Check for shared state */
		if (bprm->unsafe & LSM_UNSAFE_SHARE) {
			rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
					  SECCLASS_PROCESS, PROCESS__SHARE,
					  NULL);
			if (rc)
				return -EPERM;
		}

		/* Make sure that anyone attempting to ptrace over a task that
		 * changes its SID has the appropriate permit */
		if (bprm->unsafe &
		    (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
			struct task_struct *tracer;
			struct task_security_struct *sec;
			u32 ptsid = 0;

			rcu_read_lock();
2149
			tracer = ptrace_parent(current);
2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163
			if (likely(tracer != NULL)) {
				sec = __task_cred(tracer)->security;
				ptsid = sec->sid;
			}
			rcu_read_unlock();

			if (ptsid != 0) {
				rc = avc_has_perm(ptsid, new_tsec->sid,
						  SECCLASS_PROCESS,
						  PROCESS__PTRACE, NULL);
				if (rc)
					return -EPERM;
			}
		}
L
Linus Torvalds 已提交
2164

2165 2166
		/* Clear any possibly unsafe personality bits on exec: */
		bprm->per_clear |= PER_CLEAR_ON_SETID;
L
Linus Torvalds 已提交
2167 2168 2169 2170 2171
	}

	return 0;
}

2172
static int selinux_bprm_secureexec(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2173
{
2174
	const struct task_security_struct *tsec = current_security();
2175
	u32 sid, osid;
L
Linus Torvalds 已提交
2176 2177
	int atsecure = 0;

2178 2179 2180 2181
	sid = tsec->sid;
	osid = tsec->osid;

	if (osid != sid) {
L
Linus Torvalds 已提交
2182 2183 2184
		/* Enable secure mode for SIDs transitions unless
		   the noatsecure permission is granted between
		   the two SIDs, i.e. ahp returns 0. */
2185
		atsecure = avc_has_perm(osid, sid,
2186 2187
					SECCLASS_PROCESS,
					PROCESS__NOATSECURE, NULL);
L
Linus Torvalds 已提交
2188 2189
	}

2190
	return (atsecure || cap_bprm_secureexec(bprm));
L
Linus Torvalds 已提交
2191 2192
}

A
Al Viro 已提交
2193 2194 2195 2196 2197
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
2198
/* Derived from fs/exec.c:flush_old_files. */
2199 2200
static inline void flush_unauthorized_files(const struct cred *cred,
					    struct files_struct *files)
L
Linus Torvalds 已提交
2201 2202
{
	struct file *file, *devnull = NULL;
2203
	struct tty_struct *tty;
2204
	int drop_tty = 0;
A
Al Viro 已提交
2205
	unsigned n;
L
Linus Torvalds 已提交
2206

2207
	tty = get_current_tty();
L
Linus Torvalds 已提交
2208
	if (tty) {
N
Nick Piggin 已提交
2209
		spin_lock(&tty_files_lock);
2210
		if (!list_empty(&tty->tty_files)) {
N
Nick Piggin 已提交
2211
			struct tty_file_private *file_priv;
2212

L
Linus Torvalds 已提交
2213
			/* Revalidate access to controlling tty.
2214 2215 2216 2217
			   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
2218 2219 2220
			file_priv = list_first_entry(&tty->tty_files,
						struct tty_file_private, list);
			file = file_priv->file;
2221
			if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE))
2222
				drop_tty = 1;
L
Linus Torvalds 已提交
2223
		}
N
Nick Piggin 已提交
2224
		spin_unlock(&tty_files_lock);
A
Alan Cox 已提交
2225
		tty_kref_put(tty);
L
Linus Torvalds 已提交
2226
	}
2227 2228 2229
	/* Reset controlling tty. */
	if (drop_tty)
		no_tty();
L
Linus Torvalds 已提交
2230 2231

	/* Revalidate access to inherited open files. */
A
Al Viro 已提交
2232 2233 2234
	n = iterate_fd(files, 0, match_file, cred);
	if (!n) /* none found? */
		return;
L
Linus Torvalds 已提交
2235

A
Al Viro 已提交
2236
	devnull = dentry_open(&selinux_null, O_RDWR, cred);
A
Al Viro 已提交
2237 2238 2239 2240 2241 2242 2243
	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
2244
		fput(devnull);
L
Linus Torvalds 已提交
2245 2246
}

2247 2248 2249 2250
/*
 * 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
2251
{
2252 2253 2254
	struct task_security_struct *new_tsec;
	struct rlimit *rlim, *initrlim;
	int rc, i;
D
David Howells 已提交
2255

2256 2257 2258
	new_tsec = bprm->cred->security;
	if (new_tsec->sid == new_tsec->osid)
		return;
L
Linus Torvalds 已提交
2259

2260 2261
	/* Close files for which the new task SID is not authorized. */
	flush_unauthorized_files(bprm->cred, current->files);
R
Roland McGrath 已提交
2262

2263 2264
	/* Always clear parent death signal on SID transitions. */
	current->pdeath_signal = 0;
R
Roland McGrath 已提交
2265

2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278
	/* 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) {
2279 2280
		/* protect against do_prlimit() */
		task_lock(current);
2281 2282 2283 2284
		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
2285
		}
2286 2287
		task_unlock(current);
		update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
L
Linus Torvalds 已提交
2288 2289 2290 2291
	}
}

/*
2292 2293
 * Clean up the process immediately after the installation of new credentials
 * due to exec
L
Linus Torvalds 已提交
2294
 */
2295
static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
L
Linus Torvalds 已提交
2296
{
2297
	const struct task_security_struct *tsec = current_security();
L
Linus Torvalds 已提交
2298
	struct itimerval itimer;
2299
	u32 osid, sid;
L
Linus Torvalds 已提交
2300 2301
	int rc, i;

2302 2303 2304 2305
	osid = tsec->osid;
	sid = tsec->sid;

	if (sid == osid)
L
Linus Torvalds 已提交
2306 2307
		return;

2308 2309 2310 2311 2312 2313 2314 2315
	/* 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
2316 2317 2318 2319 2320
	if (rc) {
		memset(&itimer, 0, sizeof itimer);
		for (i = 0; i < 3; i++)
			do_setitimer(i, &itimer, NULL);
		spin_lock_irq(&current->sighand->siglock);
2321 2322 2323 2324 2325
		if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
			__flush_signals(current);
			flush_signal_handlers(current, 1);
			sigemptyset(&current->blocked);
		}
L
Linus Torvalds 已提交
2326 2327 2328
		spin_unlock_irq(&current->sighand->siglock);
	}

2329 2330
	/* Wake up the parent if it is waiting so that it can recheck
	 * wait permission to the new task SID. */
2331
	read_lock(&tasklist_lock);
2332
	__wake_up_parent(current, current->real_parent);
2333
	read_unlock(&tasklist_lock);
L
Linus Torvalds 已提交
2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357
}

/* 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)
{
2358 2359 2360
	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) ||
2361 2362
		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
2363 2364 2365 2366 2367 2368 2369
}

static inline void take_option(char **to, char *from, int *first, int len)
{
	if (!*first) {
		**to = ',';
		*to += 1;
2370
	} else
L
Linus Torvalds 已提交
2371 2372 2373 2374 2375
		*first = 0;
	memcpy(*to, from, len);
	*to += len;
}

2376 2377
static inline void take_selinux_option(char **to, char *from, int *first,
				       int len)
2378 2379 2380 2381 2382 2383
{
	int current_size = 0;

	if (!*first) {
		**to = '|';
		*to += 1;
2384
	} else
2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396
		*first = 0;

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

2397
static int selinux_sb_copy_data(char *orig, char *copy)
L
Linus Torvalds 已提交
2398 2399 2400 2401
{
	int fnosec, fsec, rc = 0;
	char *in_save, *in_curr, *in_end;
	char *sec_curr, *nosec_save, *nosec;
2402
	int open_quote = 0;
L
Linus Torvalds 已提交
2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417

	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 {
2418 2419 2420 2421
		if (*in_end == '"')
			open_quote = !open_quote;
		if ((*in_end == ',' && open_quote == 0) ||
				*in_end == '\0') {
L
Linus Torvalds 已提交
2422 2423 2424
			int len = in_end - in_curr;

			if (selinux_option(in_curr, len))
2425
				take_selinux_option(&sec_curr, in_curr, &fsec, len);
L
Linus Torvalds 已提交
2426 2427 2428 2429 2430 2431 2432
			else
				take_option(&nosec, in_curr, &fnosec, len);

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

2433
	strcpy(in_save, nosec_save);
2434
	free_page((unsigned long)nosec_save);
L
Linus Torvalds 已提交
2435 2436 2437 2438
out:
	return rc;
}

2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473
static int selinux_sb_remount(struct super_block *sb, void *data)
{
	int rc, i, *flags;
	struct security_mnt_opts opts;
	char *secdata, **mount_options;
	struct superblock_security_struct *sbsec = sb->s_security;

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

	if (!data)
		return 0;

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

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

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

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

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

2474
		if (flags[i] == SBLABEL_MNT)
2475 2476 2477 2478 2479
			continue;
		len = strlen(mount_options[i]);
		rc = security_context_to_sid(mount_options[i], len, &sid);
		if (rc) {
			printk(KERN_WARNING "SELinux: security_context_to_sid"
2480 2481
			       "(%s) failed for (dev %s, type %s) errno=%d\n",
			       mount_options[i], sb->s_id, sb->s_type->name, rc);
2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518
			goto out_free_opts;
		}
		rc = -EINVAL;
		switch (flags[i]) {
		case FSCONTEXT_MNT:
			if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
				goto out_bad_option;
			break;
		case CONTEXT_MNT:
			if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
				goto out_bad_option;
			break;
		case ROOTCONTEXT_MNT: {
			struct inode_security_struct *root_isec;
			root_isec = sb->s_root->d_inode->i_security;

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

	rc = 0;
out_free_opts:
	security_free_mnt_opts(&opts);
out_free_secdata:
	free_secdata(secdata);
	return rc;
out_bad_option:
	printk(KERN_WARNING "SELinux: unable to change security options "
2519 2520
	       "during remount (dev %s, type=%s)\n", sb->s_id,
	       sb->s_type->name);
2521 2522 2523
	goto out_free_opts;
}

2524
static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
L
Linus Torvalds 已提交
2525
{
2526
	const struct cred *cred = current_cred();
2527
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2528 2529 2530 2531 2532 2533
	int rc;

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

2534 2535 2536 2537
	/* Allow all mounts performed by the kernel */
	if (flags & MS_KERNMOUNT)
		return 0;

2538
	ad.type = LSM_AUDIT_DATA_DENTRY;
2539
	ad.u.dentry = sb->s_root;
2540
	return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
L
Linus Torvalds 已提交
2541 2542
}

2543
static int selinux_sb_statfs(struct dentry *dentry)
L
Linus Torvalds 已提交
2544
{
2545
	const struct cred *cred = current_cred();
2546
	struct common_audit_data ad;
L
Linus Torvalds 已提交
2547

2548
	ad.type = LSM_AUDIT_DATA_DENTRY;
2549
	ad.u.dentry = dentry->d_sb->s_root;
2550
	return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
L
Linus Torvalds 已提交
2551 2552
}

A
Al Viro 已提交
2553
static int selinux_mount(const char *dev_name,
2554
			 struct path *path,
A
Al Viro 已提交
2555
			 const char *type,
2556 2557
			 unsigned long flags,
			 void *data)
L
Linus Torvalds 已提交
2558
{
2559
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2560 2561

	if (flags & MS_REMOUNT)
2562
		return superblock_has_perm(cred, path->dentry->d_sb,
2563
					   FILESYSTEM__REMOUNT, NULL);
L
Linus Torvalds 已提交
2564
	else
E
Eric Paris 已提交
2565
		return path_has_perm(cred, path, FILE__MOUNTON);
L
Linus Torvalds 已提交
2566 2567 2568 2569
}

static int selinux_umount(struct vfsmount *mnt, int flags)
{
2570
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2571

2572
	return superblock_has_perm(cred, mnt->mnt_sb,
2573
				   FILESYSTEM__UNMOUNT, NULL);
L
Linus Torvalds 已提交
2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587
}

/* 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);
}

2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621
static int selinux_dentry_init_security(struct dentry *dentry, int mode,
					struct qstr *name, void **ctx,
					u32 *ctxlen)
{
	const struct cred *cred = current_cred();
	struct task_security_struct *tsec;
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
	struct inode *dir = dentry->d_parent->d_inode;
	u32 newsid;
	int rc;

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

	if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
		newsid = tsec->create_sid;
	} else {
		rc = security_transition_sid(tsec->sid, dsec->sid,
					     inode_mode_to_security_class(mode),
					     name,
					     &newsid);
		if (rc) {
			printk(KERN_WARNING
				"%s: security_transition_sid failed, rc=%d\n",
			       __func__, -rc);
			return rc;
		}
	}

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

2622
static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2623 2624
				       const struct qstr *qstr,
				       const char **name,
2625
				       void **value, size_t *len)
2626
{
2627
	const struct task_security_struct *tsec = current_security();
2628 2629
	struct inode_security_struct *dsec;
	struct superblock_security_struct *sbsec;
2630
	u32 sid, newsid, clen;
2631
	int rc;
2632
	char *context;
2633 2634 2635 2636

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

2637 2638 2639
	sid = tsec->sid;
	newsid = tsec->create_sid;

2640 2641 2642
	if ((sbsec->flags & SE_SBINITIALIZED) &&
	    (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
		newsid = sbsec->mntpoint_sid;
2643
	else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) {
2644
		rc = security_transition_sid(sid, dsec->sid,
2645
					     inode_mode_to_security_class(inode->i_mode),
2646
					     qstr, &newsid);
2647 2648 2649 2650
		if (rc) {
			printk(KERN_WARNING "%s:  "
			       "security_transition_sid failed, rc=%d (dev=%s "
			       "ino=%ld)\n",
2651
			       __func__,
2652 2653 2654 2655 2656
			       -rc, inode->i_sb->s_id, inode->i_ino);
			return rc;
		}
	}

2657
	/* Possibly defer initialization to selinux_complete_init. */
2658
	if (sbsec->flags & SE_SBINITIALIZED) {
2659 2660 2661 2662 2663
		struct inode_security_struct *isec = inode->i_security;
		isec->sclass = inode_mode_to_security_class(inode->i_mode);
		isec->sid = newsid;
		isec->initialized = 1;
	}
2664

2665
	if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
2666 2667
		return -EOPNOTSUPP;

2668 2669
	if (name)
		*name = XATTR_SELINUX_SUFFIX;
2670

2671
	if (value && len) {
2672
		rc = security_sid_to_context_force(newsid, &context, &clen);
2673
		if (rc)
2674 2675 2676
			return rc;
		*value = context;
		*len = clen;
2677 2678 2679 2680 2681
	}

	return 0;
}

A
Al Viro 已提交
2682
static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
L
Linus Torvalds 已提交
2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701
{
	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);
}

2702
static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
L
Linus Torvalds 已提交
2703 2704 2705 2706 2707 2708 2709 2710 2711
{
	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
2712
static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
L
Linus Torvalds 已提交
2713 2714 2715 2716 2717
{
	return may_create(dir, dentry, inode_mode_to_security_class(mode));
}

static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2718
				struct inode *new_inode, struct dentry *new_dentry)
L
Linus Torvalds 已提交
2719 2720 2721 2722 2723 2724
{
	return may_rename(old_inode, old_dentry, new_inode, new_dentry);
}

static int selinux_inode_readlink(struct dentry *dentry)
{
2725 2726
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2727
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
2728 2729 2730 2731
}

static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
{
2732
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
2733

E
Eric Paris 已提交
2734
	return dentry_has_perm(cred, dentry, FILE__READ);
L
Linus Torvalds 已提交
2735 2736
}

2737 2738 2739
static noinline int audit_inode_permission(struct inode *inode,
					   u32 perms, u32 audited, u32 denied,
					   unsigned flags)
L
Linus Torvalds 已提交
2740
{
2741
	struct common_audit_data ad;
2742 2743 2744
	struct inode_security_struct *isec = inode->i_security;
	int rc;

2745
	ad.type = LSM_AUDIT_DATA_INODE;
2746 2747 2748 2749 2750 2751 2752 2753 2754
	ad.u.inode = inode;

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

2755
static int selinux_inode_permission(struct inode *inode, int mask)
L
Linus Torvalds 已提交
2756
{
2757
	const struct cred *cred = current_cred();
2758 2759
	u32 perms;
	bool from_access;
2760
	unsigned flags = mask & MAY_NOT_BLOCK;
2761 2762 2763 2764 2765
	struct inode_security_struct *isec;
	u32 sid;
	struct av_decision avd;
	int rc, rc2;
	u32 audited, denied;
L
Linus Torvalds 已提交
2766

2767
	from_access = mask & MAY_ACCESS;
2768 2769
	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);

2770 2771
	/* No permission to check.  Existence test. */
	if (!mask)
L
Linus Torvalds 已提交
2772 2773
		return 0;

2774
	validate_creds(cred);
2775

2776 2777
	if (unlikely(IS_PRIVATE(inode)))
		return 0;
2778 2779 2780

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

2781 2782 2783 2784 2785 2786 2787 2788 2789 2790
	sid = cred_sid(cred);
	isec = inode->i_security;

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

2791
	rc2 = audit_inode_permission(inode, perms, audited, denied, flags);
2792 2793 2794
	if (rc2)
		return rc2;
	return rc;
L
Linus Torvalds 已提交
2795 2796 2797 2798
}

static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
{
2799
	const struct cred *cred = current_cred();
2800
	unsigned int ia_valid = iattr->ia_valid;
2801
	__u32 av = FILE__WRITE;
L
Linus Torvalds 已提交
2802

2803 2804 2805 2806 2807 2808 2809
	/* 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
2810

2811 2812
	if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
			ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
E
Eric Paris 已提交
2813
		return dentry_has_perm(cred, dentry, FILE__SETATTR);
L
Linus Torvalds 已提交
2814

2815
	if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE))
2816 2817 2818
		av |= FILE__OPEN;

	return dentry_has_perm(cred, dentry, av);
L
Linus Torvalds 已提交
2819 2820 2821 2822
}

static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
{
2823
	const struct cred *cred = current_cred();
E
Eric Paris 已提交
2824 2825 2826 2827
	struct path path;

	path.dentry = dentry;
	path.mnt = mnt;
2828

E
Eric Paris 已提交
2829
	return path_has_perm(cred, &path, FILE__GETATTR);
L
Linus Torvalds 已提交
2830 2831
}

2832
static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2833
{
2834 2835
	const struct cred *cred = current_cred();

2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849
	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
2850
	return dentry_has_perm(cred, dentry, FILE__SETATTR);
2851 2852
}

2853 2854
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
2855 2856 2857 2858
{
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	struct superblock_security_struct *sbsec;
2859
	struct common_audit_data ad;
2860
	u32 newsid, sid = current_sid();
L
Linus Torvalds 已提交
2861 2862
	int rc = 0;

2863 2864
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
2865 2866

	sbsec = inode->i_sb->s_security;
2867
	if (!(sbsec->flags & SBLABEL_MNT))
L
Linus Torvalds 已提交
2868 2869
		return -EOPNOTSUPP;

2870
	if (!inode_owner_or_capable(inode))
L
Linus Torvalds 已提交
2871 2872
		return -EPERM;

2873
	ad.type = LSM_AUDIT_DATA_DENTRY;
2874
	ad.u.dentry = dentry;
L
Linus Torvalds 已提交
2875

2876
	rc = avc_has_perm(sid, isec->sid, isec->sclass,
L
Linus Torvalds 已提交
2877 2878 2879 2880 2881
			  FILE__RELABELFROM, &ad);
	if (rc)
		return rc;

	rc = security_context_to_sid(value, size, &newsid);
2882
	if (rc == -EINVAL) {
2883 2884 2885 2886 2887 2888 2889
		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 */
2890 2891 2892 2893 2894 2895 2896 2897 2898 2899
			if (value) {
				str = value;
				if (str[size - 1] == '\0')
					audit_size = size - 1;
				else
					audit_size = size;
			} else {
				str = "";
				audit_size = 0;
			}
2900 2901 2902 2903 2904
			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);

2905
			return rc;
2906
		}
2907 2908
		rc = security_context_to_sid_force(value, size, &newsid);
	}
L
Linus Torvalds 已提交
2909 2910 2911
	if (rc)
		return rc;

2912
	rc = avc_has_perm(sid, newsid, isec->sclass,
L
Linus Torvalds 已提交
2913 2914 2915 2916
			  FILE__RELABELTO, &ad);
	if (rc)
		return rc;

2917
	rc = security_validate_transition(isec->sid, newsid, sid,
2918
					  isec->sclass);
L
Linus Torvalds 已提交
2919 2920 2921 2922 2923 2924 2925 2926 2927 2928
	if (rc)
		return rc;

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

2929
static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2930
					const void *value, size_t size,
2931
					int flags)
L
Linus Torvalds 已提交
2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942
{
	struct inode *inode = dentry->d_inode;
	struct inode_security_struct *isec = inode->i_security;
	u32 newsid;
	int rc;

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

2943
	rc = security_context_to_sid_force(value, size, &newsid);
L
Linus Torvalds 已提交
2944
	if (rc) {
2945 2946 2947
		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
2948 2949 2950
		return;
	}

2951
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
2952
	isec->sid = newsid;
2953 2954
	isec->initialized = 1;

L
Linus Torvalds 已提交
2955 2956 2957
	return;
}

2958
static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
2959
{
2960 2961
	const struct cred *cred = current_cred();

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

2965
static int selinux_inode_listxattr(struct dentry *dentry)
L
Linus Torvalds 已提交
2966
{
2967 2968
	const struct cred *cred = current_cred();

E
Eric Paris 已提交
2969
	return dentry_has_perm(cred, dentry, FILE__GETATTR);
L
Linus Torvalds 已提交
2970 2971
}

2972
static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
L
Linus Torvalds 已提交
2973
{
2974 2975
	if (strcmp(name, XATTR_NAME_SELINUX))
		return selinux_inode_setotherxattr(dentry, name);
L
Linus Torvalds 已提交
2976 2977 2978 2979 2980 2981

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

2982
/*
2983
 * Copy the inode security context value to the user.
2984 2985 2986
 *
 * Permission check is handled by selinux_inode_getxattr hook.
 */
2987
static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
L
Linus Torvalds 已提交
2988
{
2989 2990 2991
	u32 size;
	int error;
	char *context = NULL;
L
Linus Torvalds 已提交
2992
	struct inode_security_struct *isec = inode->i_security;
2993

2994 2995
	if (strcmp(name, XATTR_SELINUX_SUFFIX))
		return -EOPNOTSUPP;
2996

2997 2998 2999 3000 3001 3002 3003 3004 3005
	/*
	 * 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.
	 */
3006
	error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
3007
				SECURITY_CAP_NOAUDIT);
3008 3009 3010 3011 3012
	if (!error)
		error = security_sid_to_context_force(isec->sid, &context,
						      &size);
	else
		error = security_sid_to_context(isec->sid, &context, &size);
3013 3014 3015 3016 3017 3018 3019 3020 3021 3022
	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
3023 3024 3025
}

static int selinux_inode_setsecurity(struct inode *inode, const char *name,
3026
				     const void *value, size_t size, int flags)
L
Linus Torvalds 已提交
3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037
{
	struct inode_security_struct *isec = inode->i_security;
	u32 newsid;
	int rc;

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

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

3038
	rc = security_context_to_sid((void *)value, size, &newsid);
L
Linus Torvalds 已提交
3039 3040 3041
	if (rc)
		return rc;

3042
	isec->sclass = inode_mode_to_security_class(inode->i_mode);
L
Linus Torvalds 已提交
3043
	isec->sid = newsid;
3044
	isec->initialized = 1;
L
Linus Torvalds 已提交
3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055
	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;
}

3056 3057 3058 3059 3060 3061
static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
{
	struct inode_security_struct *isec = inode->i_security;
	*secid = isec->sid;
}

L
Linus Torvalds 已提交
3062 3063
/* file security operations */

3064
static int selinux_revalidate_file_permission(struct file *file, int mask)
L
Linus Torvalds 已提交
3065
{
3066
	const struct cred *cred = current_cred();
A
Al Viro 已提交
3067
	struct inode *inode = file_inode(file);
L
Linus Torvalds 已提交
3068 3069 3070 3071 3072

	/* 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;

3073 3074
	return file_has_perm(cred, file,
			     file_mask_to_av(inode->i_mode, mask));
L
Linus Torvalds 已提交
3075 3076
}

3077 3078
static int selinux_file_permission(struct file *file, int mask)
{
A
Al Viro 已提交
3079
	struct inode *inode = file_inode(file);
3080 3081 3082 3083
	struct file_security_struct *fsec = file->f_security;
	struct inode_security_struct *isec = inode->i_security;
	u32 sid = current_sid();

3084
	if (!mask)
3085 3086 3087
		/* No permission to check.  Existence test. */
		return 0;

3088 3089
	if (sid == fsec->sid && fsec->isid == isec->sid &&
	    fsec->pseqno == avc_policy_seqno())
3090
		/* No change since file_open check. */
3091 3092
		return 0;

3093 3094 3095
	return selinux_revalidate_file_permission(file, mask);
}

L
Linus Torvalds 已提交
3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108
static int selinux_file_alloc_security(struct file *file)
{
	return file_alloc_security(file);
}

static void selinux_file_free_security(struct file *file)
{
	file_free_security(file);
}

static int selinux_file_ioctl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3109
	const struct cred *cred = current_cred();
3110
	int error = 0;
L
Linus Torvalds 已提交
3111

3112 3113 3114 3115 3116 3117 3118
	switch (cmd) {
	case FIONREAD:
	/* fall through */
	case FIBMAP:
	/* fall through */
	case FIGETBSZ:
	/* fall through */
3119
	case FS_IOC_GETFLAGS:
3120
	/* fall through */
3121
	case FS_IOC_GETVERSION:
3122 3123
		error = file_has_perm(cred, file, FILE__GETATTR);
		break;
L
Linus Torvalds 已提交
3124

3125
	case FS_IOC_SETFLAGS:
3126
	/* fall through */
3127
	case FS_IOC_SETVERSION:
3128 3129 3130 3131 3132 3133 3134 3135 3136
		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
3137

3138 3139
	case KDSKBENT:
	case KDSKBSENT:
3140 3141
		error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
					    SECURITY_CAP_AUDIT);
3142 3143 3144 3145 3146 3147 3148 3149 3150
		break;

	/* default case assumes that the command will go
	 * to the file's ioctl() function.
	 */
	default:
		error = file_has_perm(cred, file, FILE__IOCTL);
	}
	return error;
L
Linus Torvalds 已提交
3151 3152
}

3153 3154
static int default_noexec;

L
Linus Torvalds 已提交
3155 3156
static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
{
3157
	const struct cred *cred = current_cred();
D
David Howells 已提交
3158
	int rc = 0;
3159

3160 3161
	if (default_noexec &&
	    (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
L
Linus Torvalds 已提交
3162 3163 3164 3165 3166
		/*
		 * We are making executable an anonymous mapping or a
		 * private file mapping that will also be writable.
		 * This has an additional check.
		 */
D
David Howells 已提交
3167
		rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
L
Linus Torvalds 已提交
3168
		if (rc)
D
David Howells 已提交
3169
			goto error;
L
Linus Torvalds 已提交
3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182
	}

	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;

3183
		return file_has_perm(cred, file, av);
L
Linus Torvalds 已提交
3184
	}
D
David Howells 已提交
3185 3186 3187

error:
	return rc;
L
Linus Torvalds 已提交
3188 3189
}

3190
static int selinux_mmap_addr(unsigned long addr)
L
Linus Torvalds 已提交
3191
{
3192
	int rc = 0;
3193
	u32 sid = current_sid();
L
Linus Torvalds 已提交
3194

3195 3196 3197 3198 3199 3200
	/*
	 * notice that we are intentionally putting the SELinux check before
	 * the secondary cap_file_mmap check.  This is such a likely attempt
	 * at bad behaviour/exploit that we always want to get the AVC, even
	 * if DAC would have also denied the operation.
	 */
3201
	if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3202 3203
		rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
				  MEMPROTECT__MMAP_ZERO, NULL);
3204 3205 3206 3207 3208
		if (rc)
			return rc;
	}

	/* do DAC check on address space usage */
3209 3210
	return cap_mmap_addr(addr);
}
L
Linus Torvalds 已提交
3211

3212 3213 3214
static int selinux_mmap_file(struct file *file, unsigned long reqprot,
			     unsigned long prot, unsigned long flags)
{
L
Linus Torvalds 已提交
3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225
	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)
{
3226
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3227 3228 3229 3230

	if (selinux_checkreqprot)
		prot = reqprot;

3231 3232
	if (default_noexec &&
	    (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3233
		int rc = 0;
3234 3235
		if (vma->vm_start >= vma->vm_mm->start_brk &&
		    vma->vm_end <= vma->vm_mm->brk) {
D
David Howells 已提交
3236
			rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3237 3238 3239
		} else if (!vma->vm_file &&
			   vma->vm_start <= vma->vm_mm->start_stack &&
			   vma->vm_end >= vma->vm_mm->start_stack) {
3240
			rc = current_has_perm(current, PROCESS__EXECSTACK);
3241 3242 3243 3244 3245 3246 3247 3248
		} 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
3249
			rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3250
		}
3251 3252 3253
		if (rc)
			return rc;
	}
L
Linus Torvalds 已提交
3254 3255 3256 3257 3258 3259

	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)
{
3260 3261 3262
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, FILE__LOCK);
L
Linus Torvalds 已提交
3263 3264 3265 3266 3267
}

static int selinux_file_fcntl(struct file *file, unsigned int cmd,
			      unsigned long arg)
{
3268
	const struct cred *cred = current_cred();
L
Linus Torvalds 已提交
3269 3270 3271
	int err = 0;

	switch (cmd) {
3272 3273
	case F_SETFL:
		if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3274
			err = file_has_perm(cred, file, FILE__WRITE);
L
Linus Torvalds 已提交
3275
			break;
3276 3277 3278 3279 3280 3281 3282
		}
		/* fall through */
	case F_SETOWN:
	case F_SETSIG:
	case F_GETFL:
	case F_GETOWN:
	case F_GETSIG:
3283
	case F_GETOWNER_UIDS:
3284
		/* Just check FD__USE permission */
3285
		err = file_has_perm(cred, file, 0);
3286 3287 3288 3289
		break;
	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
L
Linus Torvalds 已提交
3290
#if BITS_PER_LONG == 32
3291 3292 3293
	case F_GETLK64:
	case F_SETLK64:
	case F_SETLKW64:
L
Linus Torvalds 已提交
3294
#endif
3295
		err = file_has_perm(cred, file, FILE__LOCK);
3296
		break;
L
Linus Torvalds 已提交
3297 3298 3299 3300 3301 3302 3303 3304 3305 3306
	}

	return err;
}

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

	fsec = file->f_security;
3307
	fsec->fown_sid = current_sid();
L
Linus Torvalds 已提交
3308 3309 3310 3311 3312 3313 3314

	return 0;
}

static int selinux_file_send_sigiotask(struct task_struct *tsk,
				       struct fown_struct *fown, int signum)
{
3315
	struct file *file;
3316
	u32 sid = task_sid(tsk);
L
Linus Torvalds 已提交
3317 3318 3319 3320
	u32 perm;
	struct file_security_struct *fsec;

	/* struct fown_struct is never outside the context of a struct file */
3321
	file = container_of(fown, struct file, f_owner);
L
Linus Torvalds 已提交
3322 3323 3324 3325 3326 3327 3328 3329

	fsec = file->f_security;

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

3330
	return avc_has_perm(fsec->fown_sid, sid,
L
Linus Torvalds 已提交
3331 3332 3333 3334 3335
			    SECCLASS_PROCESS, perm, NULL);
}

static int selinux_file_receive(struct file *file)
{
3336 3337 3338
	const struct cred *cred = current_cred();

	return file_has_perm(cred, file, file_to_av(file));
L
Linus Torvalds 已提交
3339 3340
}

3341
static int selinux_file_open(struct file *file, const struct cred *cred)
3342 3343 3344
{
	struct file_security_struct *fsec;
	struct inode_security_struct *isec;
D
David Howells 已提交
3345

3346
	fsec = file->f_security;
A
Al Viro 已提交
3347
	isec = file_inode(file)->i_security;
3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364
	/*
	 * 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.
	 */
3365
	return file_path_has_perm(cred, file, open_file_to_av(file));
3366 3367
}

L
Linus Torvalds 已提交
3368 3369 3370 3371
/* task security operations */

static int selinux_task_create(unsigned long clone_flags)
{
3372
	return current_has_perm(current, PROCESS__FORK);
L
Linus Torvalds 已提交
3373 3374
}

3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389
/*
 * 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
3390 3391 3392 3393
/*
 * 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
3394
{
D
David Howells 已提交
3395
	struct task_security_struct *tsec = cred->security;
3396

3397 3398 3399 3400 3401
	/*
	 * 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);
3402
	cred->security = (void *) 0x7UL;
D
David Howells 已提交
3403 3404
	kfree(tsec);
}
L
Linus Torvalds 已提交
3405

D
David Howells 已提交
3406 3407 3408 3409 3410 3411 3412 3413
/*
 * 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
3414

D
David Howells 已提交
3415
	old_tsec = old->security;
L
Linus Torvalds 已提交
3416

D
David Howells 已提交
3417 3418 3419
	tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
	if (!tsec)
		return -ENOMEM;
L
Linus Torvalds 已提交
3420

D
David Howells 已提交
3421
	new->security = tsec;
L
Linus Torvalds 已提交
3422 3423 3424
	return 0;
}

3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435
/*
 * 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;
}

3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476
/*
 * set the security data for a kernel service
 * - all the creation contexts are set to unlabelled
 */
static int selinux_kernel_act_as(struct cred *new, u32 secid)
{
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

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

/*
 * set the file creation context in a security record to the same as the
 * objective context of the specified inode
 */
static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
	struct task_security_struct *tsec = new->security;
	u32 sid = current_sid();
	int ret;

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

	if (ret == 0)
		tsec->create_sid = isec->sid;
3477
	return ret;
3478 3479
}

3480
static int selinux_kernel_module_request(char *kmod_name)
3481
{
3482 3483 3484 3485 3486
	u32 sid;
	struct common_audit_data ad;

	sid = task_sid(current);

3487
	ad.type = LSM_AUDIT_DATA_KMOD;
3488 3489 3490 3491
	ad.u.kmod_name = kmod_name;

	return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
			    SYSTEM__MODULE_REQUEST, &ad);
3492 3493
}

L
Linus Torvalds 已提交
3494 3495
static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
{
3496
	return current_has_perm(p, PROCESS__SETPGID);
L
Linus Torvalds 已提交
3497 3498 3499 3500
}

static int selinux_task_getpgid(struct task_struct *p)
{
3501
	return current_has_perm(p, PROCESS__GETPGID);
L
Linus Torvalds 已提交
3502 3503 3504 3505
}

static int selinux_task_getsid(struct task_struct *p)
{
3506
	return current_has_perm(p, PROCESS__GETSESSION);
L
Linus Torvalds 已提交
3507 3508
}

3509 3510
static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
{
3511
	*secid = task_sid(p);
3512 3513
}

L
Linus Torvalds 已提交
3514 3515 3516 3517
static int selinux_task_setnice(struct task_struct *p, int nice)
{
	int rc;

3518
	rc = cap_task_setnice(p, nice);
L
Linus Torvalds 已提交
3519 3520 3521
	if (rc)
		return rc;

3522
	return current_has_perm(p, PROCESS__SETSCHED);
L
Linus Torvalds 已提交
3523 3524
}

3525 3526
static int selinux_task_setioprio(struct task_struct *p, int ioprio)
{
3527 3528
	int rc;

3529
	rc = cap_task_setioprio(p, ioprio);
3530 3531 3532
	if (rc)
		return rc;

3533
	return current_has_perm(p, PROCESS__SETSCHED);
3534 3535
}

3536 3537
static int selinux_task_getioprio(struct task_struct *p)
{
3538
	return current_has_perm(p, PROCESS__GETSCHED);
3539 3540
}

3541 3542
static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
		struct rlimit *new_rlim)
L
Linus Torvalds 已提交
3543
{
3544
	struct rlimit *old_rlim = p->signal->rlim + resource;
L
Linus Torvalds 已提交
3545 3546 3547 3548

	/* 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
3549
	   upon context transitions.  See selinux_bprm_committing_creds. */
L
Linus Torvalds 已提交
3550
	if (old_rlim->rlim_max != new_rlim->rlim_max)
3551
		return current_has_perm(p, PROCESS__SETRLIMIT);
L
Linus Torvalds 已提交
3552 3553 3554 3555

	return 0;
}

3556
static int selinux_task_setscheduler(struct task_struct *p)
L
Linus Torvalds 已提交
3557
{
3558 3559
	int rc;

3560
	rc = cap_task_setscheduler(p);
3561 3562 3563
	if (rc)
		return rc;

3564
	return current_has_perm(p, PROCESS__SETSCHED);
L
Linus Torvalds 已提交
3565 3566 3567 3568
}

static int selinux_task_getscheduler(struct task_struct *p)
{
3569
	return current_has_perm(p, PROCESS__GETSCHED);
L
Linus Torvalds 已提交
3570 3571
}

3572 3573
static int selinux_task_movememory(struct task_struct *p)
{
3574
	return current_has_perm(p, PROCESS__SETSCHED);
3575 3576
}

3577 3578
static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
				int sig, u32 secid)
L
Linus Torvalds 已提交
3579 3580 3581 3582 3583 3584 3585 3586
{
	u32 perm;
	int rc;

	if (!sig)
		perm = PROCESS__SIGNULL; /* null signal; existence test */
	else
		perm = signal_to_av(sig);
3587
	if (secid)
3588 3589
		rc = avc_has_perm(secid, task_sid(p),
				  SECCLASS_PROCESS, perm, NULL);
3590
	else
3591
		rc = current_has_perm(p, perm);
3592
	return rc;
L
Linus Torvalds 已提交
3593 3594 3595 3596
}

static int selinux_task_wait(struct task_struct *p)
{
3597
	return task_has_perm(p, current, PROCESS__SIGCHLD);
L
Linus Torvalds 已提交
3598 3599 3600 3601 3602 3603
}

static void selinux_task_to_inode(struct task_struct *p,
				  struct inode *inode)
{
	struct inode_security_struct *isec = inode->i_security;
3604
	u32 sid = task_sid(p);
L
Linus Torvalds 已提交
3605

3606
	isec->sid = sid;
L
Linus Torvalds 已提交
3607 3608 3609 3610
	isec->initialized = 1;
}

/* Returns error only if unable to parse addresses */
3611
static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3612
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
3613 3614 3615 3616
{
	int offset, ihlen, ret = -EINVAL;
	struct iphdr _iph, *ih;

3617
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
3618 3619 3620 3621 3622 3623 3624 3625
	ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
	if (ih == NULL)
		goto out;

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

3626 3627
	ad->u.net->v4info.saddr = ih->saddr;
	ad->u.net->v4info.daddr = ih->daddr;
L
Linus Torvalds 已提交
3628 3629
	ret = 0;

3630 3631 3632
	if (proto)
		*proto = ih->protocol;

L
Linus Torvalds 已提交
3633
	switch (ih->protocol) {
3634 3635
	case IPPROTO_TCP: {
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
3636

3637 3638
		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;
L
Linus Torvalds 已提交
3639 3640 3641 3642 3643 3644

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

3645 3646
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
3647
		break;
3648 3649 3650 3651 3652 3653 3654 3655
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

L
Linus Torvalds 已提交
3656
		offset += ihlen;
3657
		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
L
Linus Torvalds 已提交
3658
		if (uh == NULL)
3659
			break;
L
Linus Torvalds 已提交
3660

3661 3662
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
3663 3664
		break;
	}
L
Linus Torvalds 已提交
3665

J
James Morris 已提交
3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676
	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;

3677 3678
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
3679
		break;
3680
	}
J
James Morris 已提交
3681

3682 3683 3684
	default:
		break;
	}
L
Linus Torvalds 已提交
3685 3686 3687 3688 3689 3690 3691
out:
	return ret;
}

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

/* Returns error only if unable to parse addresses */
3692
static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3693
			struct common_audit_data *ad, u8 *proto)
L
Linus Torvalds 已提交
3694 3695 3696 3697
{
	u8 nexthdr;
	int ret = -EINVAL, offset;
	struct ipv6hdr _ipv6h, *ip6;
3698
	__be16 frag_off;
L
Linus Torvalds 已提交
3699

3700
	offset = skb_network_offset(skb);
L
Linus Torvalds 已提交
3701 3702 3703 3704
	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
	if (ip6 == NULL)
		goto out;

3705 3706
	ad->u.net->v6info.saddr = ip6->saddr;
	ad->u.net->v6info.daddr = ip6->daddr;
L
Linus Torvalds 已提交
3707 3708 3709 3710
	ret = 0;

	nexthdr = ip6->nexthdr;
	offset += sizeof(_ipv6h);
3711
	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
L
Linus Torvalds 已提交
3712 3713 3714
	if (offset < 0)
		goto out;

3715 3716 3717
	if (proto)
		*proto = nexthdr;

L
Linus Torvalds 已提交
3718 3719
	switch (nexthdr) {
	case IPPROTO_TCP: {
3720
		struct tcphdr _tcph, *th;
L
Linus Torvalds 已提交
3721 3722 3723 3724 3725

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

3726 3727
		ad->u.net->sport = th->source;
		ad->u.net->dport = th->dest;
L
Linus Torvalds 已提交
3728 3729 3730 3731 3732 3733 3734 3735 3736 3737
		break;
	}

	case IPPROTO_UDP: {
		struct udphdr _udph, *uh;

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

3738 3739
		ad->u.net->sport = uh->source;
		ad->u.net->dport = uh->dest;
L
Linus Torvalds 已提交
3740 3741 3742
		break;
	}

J
James Morris 已提交
3743 3744 3745 3746 3747 3748 3749
	case IPPROTO_DCCP: {
		struct dccp_hdr _dccph, *dh;

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

3750 3751
		ad->u.net->sport = dh->dccph_sport;
		ad->u.net->dport = dh->dccph_dport;
J
James Morris 已提交
3752
		break;
3753
	}
J
James Morris 已提交
3754

L
Linus Torvalds 已提交
3755 3756 3757 3758 3759 3760 3761 3762 3763 3764
	/* includes fragments */
	default:
		break;
	}
out:
	return ret;
}

#endif /* IPV6 */

3765
static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3766
			     char **_addrp, int src, u8 *proto)
L
Linus Torvalds 已提交
3767
{
3768 3769
	char *addrp;
	int ret;
L
Linus Torvalds 已提交
3770

3771
	switch (ad->u.net->family) {
L
Linus Torvalds 已提交
3772
	case PF_INET:
3773
		ret = selinux_parse_skb_ipv4(skb, ad, proto);
3774 3775
		if (ret)
			goto parse_error;
3776 3777
		addrp = (char *)(src ? &ad->u.net->v4info.saddr :
				       &ad->u.net->v4info.daddr);
3778
		goto okay;
L
Linus Torvalds 已提交
3779 3780 3781

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
	case PF_INET6:
3782
		ret = selinux_parse_skb_ipv6(skb, ad, proto);
3783 3784
		if (ret)
			goto parse_error;
3785 3786
		addrp = (char *)(src ? &ad->u.net->v6info.saddr :
				       &ad->u.net->v6info.daddr);
3787
		goto okay;
L
Linus Torvalds 已提交
3788 3789
#endif	/* IPV6 */
	default:
3790 3791
		addrp = NULL;
		goto okay;
L
Linus Torvalds 已提交
3792 3793
	}

3794 3795 3796 3797
parse_error:
	printk(KERN_WARNING
	       "SELinux: failure in selinux_parse_skb(),"
	       " unable to parse packet\n");
L
Linus Torvalds 已提交
3798
	return ret;
3799 3800 3801 3802 3803

okay:
	if (_addrp)
		*_addrp = addrp;
	return 0;
L
Linus Torvalds 已提交
3804 3805
}

3806
/**
3807
 * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3808
 * @skb: the packet
3809
 * @family: protocol family
3810
 * @sid: the packet's peer label SID
3811 3812
 *
 * Description:
3813 3814 3815 3816 3817 3818
 * 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.
3819 3820
 *
 */
3821
static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3822
{
3823
	int err;
3824 3825
	u32 xfrm_sid;
	u32 nlbl_sid;
3826
	u32 nlbl_type;
3827

3828
	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);
3829 3830 3831 3832 3833
	if (unlikely(err))
		return -EACCES;
	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
	if (unlikely(err))
		return -EACCES;
3834

3835 3836 3837 3838 3839
	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");
3840
		return -EACCES;
3841
	}
3842 3843

	return 0;
3844 3845
}

3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869
/**
 * 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
3870
/* socket security operations */
3871

3872 3873
static int socket_sockcreate_sid(const struct task_security_struct *tsec,
				 u16 secclass, u32 *socksid)
3874
{
3875 3876 3877 3878 3879 3880 3881
	if (tsec->sockcreate_sid > SECSID_NULL) {
		*socksid = tsec->sockcreate_sid;
		return 0;
	}

	return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
				       socksid);
3882 3883
}

3884
static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
L
Linus Torvalds 已提交
3885
{
3886
	struct sk_security_struct *sksec = sk->sk_security;
3887
	struct common_audit_data ad;
3888
	struct lsm_network_audit net = {0,};
3889
	u32 tsid = task_sid(task);
L
Linus Torvalds 已提交
3890

3891 3892
	if (sksec->sid == SECINITSID_KERNEL)
		return 0;
L
Linus Torvalds 已提交
3893

3894
	ad.type = LSM_AUDIT_DATA_NET;
3895 3896
	ad.u.net = &net;
	ad.u.net->sk = sk;
L
Linus Torvalds 已提交
3897

3898
	return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
L
Linus Torvalds 已提交
3899 3900 3901 3902 3903
}

static int selinux_socket_create(int family, int type,
				 int protocol, int kern)
{
3904
	const struct task_security_struct *tsec = current_security();
3905
	u32 newsid;
3906
	u16 secclass;
3907
	int rc;
L
Linus Torvalds 已提交
3908 3909

	if (kern)
3910
		return 0;
3911 3912

	secclass = socket_type_to_security_class(family, type, protocol);
3913 3914 3915 3916
	rc = socket_sockcreate_sid(tsec, secclass, &newsid);
	if (rc)
		return rc;

3917
	return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
L
Linus Torvalds 已提交
3918 3919
}

V
Venkat Yekkirala 已提交
3920 3921
static int selinux_socket_post_create(struct socket *sock, int family,
				      int type, int protocol, int kern)
L
Linus Torvalds 已提交
3922
{
3923
	const struct task_security_struct *tsec = current_security();
3924
	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3925
	struct sk_security_struct *sksec;
3926 3927
	int err = 0;

3928 3929
	isec->sclass = socket_type_to_security_class(family, type, protocol);

3930 3931
	if (kern)
		isec->sid = SECINITSID_KERNEL;
3932 3933 3934 3935 3936
	else {
		err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
		if (err)
			return err;
	}
3937

L
Linus Torvalds 已提交
3938 3939
	isec->initialized = 1;

3940 3941 3942
	if (sock->sk) {
		sksec = sock->sk->sk_security;
		sksec->sid = isec->sid;
3943
		sksec->sclass = isec->sclass;
3944
		err = selinux_netlbl_socket_post_create(sock->sk, family);
3945 3946
	}

V
Venkat Yekkirala 已提交
3947
	return err;
L
Linus Torvalds 已提交
3948 3949 3950 3951 3952 3953 3954 3955
}

/* 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)
{
3956
	struct sock *sk = sock->sk;
L
Linus Torvalds 已提交
3957 3958 3959
	u16 family;
	int err;

3960
	err = sock_has_perm(current, sk, SOCKET__BIND);
L
Linus Torvalds 已提交
3961 3962 3963 3964 3965
	if (err)
		goto out;

	/*
	 * If PF_INET or PF_INET6, check name_bind permission for the port.
3966 3967
	 * Multiple address binding for SCTP is not supported yet: we just
	 * check the first address now.
L
Linus Torvalds 已提交
3968
	 */
3969
	family = sk->sk_family;
L
Linus Torvalds 已提交
3970 3971
	if (family == PF_INET || family == PF_INET6) {
		char *addrp;
3972
		struct sk_security_struct *sksec = sk->sk_security;
3973
		struct common_audit_data ad;
3974
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
3975 3976 3977
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
3978
		u32 sid, node_perm;
L
Linus Torvalds 已提交
3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989

		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;
		}

3990 3991 3992 3993 3994 3995
		if (snum) {
			int low, high;

			inet_get_local_port_range(&low, &high);

			if (snum < max(PROT_SOCK, low) || snum > high) {
P
Paul Moore 已提交
3996 3997
				err = sel_netport_sid(sk->sk_protocol,
						      snum, &sid);
3998 3999
				if (err)
					goto out;
4000
				ad.type = LSM_AUDIT_DATA_NET;
4001 4002 4003
				ad.u.net = &net;
				ad.u.net->sport = htons(snum);
				ad.u.net->family = family;
4004 4005
				err = avc_has_perm(sksec->sid, sid,
						   sksec->sclass,
4006 4007 4008 4009
						   SOCKET__NAME_BIND, &ad);
				if (err)
					goto out;
			}
L
Linus Torvalds 已提交
4010
		}
4011

4012
		switch (sksec->sclass) {
4013
		case SECCLASS_TCP_SOCKET:
L
Linus Torvalds 已提交
4014 4015
			node_perm = TCP_SOCKET__NODE_BIND;
			break;
4016

4017
		case SECCLASS_UDP_SOCKET:
L
Linus Torvalds 已提交
4018 4019
			node_perm = UDP_SOCKET__NODE_BIND;
			break;
J
James Morris 已提交
4020 4021 4022 4023 4024

		case SECCLASS_DCCP_SOCKET:
			node_perm = DCCP_SOCKET__NODE_BIND;
			break;

L
Linus Torvalds 已提交
4025 4026 4027 4028
		default:
			node_perm = RAWIP_SOCKET__NODE_BIND;
			break;
		}
4029

4030
		err = sel_netnode_sid(addrp, family, &sid);
L
Linus Torvalds 已提交
4031 4032
		if (err)
			goto out;
4033

4034
		ad.type = LSM_AUDIT_DATA_NET;
4035 4036 4037
		ad.u.net = &net;
		ad.u.net->sport = htons(snum);
		ad.u.net->family = family;
L
Linus Torvalds 已提交
4038 4039

		if (family == PF_INET)
4040
			ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
L
Linus Torvalds 已提交
4041
		else
4042
			ad.u.net->v6info.saddr = addr6->sin6_addr;
L
Linus Torvalds 已提交
4043

4044 4045
		err = avc_has_perm(sksec->sid, sid,
				   sksec->sclass, node_perm, &ad);
L
Linus Torvalds 已提交
4046 4047 4048 4049 4050 4051 4052 4053 4054
		if (err)
			goto out;
	}
out:
	return err;
}

static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
{
4055
	struct sock *sk = sock->sk;
4056
	struct sk_security_struct *sksec = sk->sk_security;
L
Linus Torvalds 已提交
4057 4058
	int err;

4059
	err = sock_has_perm(current, sk, SOCKET__CONNECT);
L
Linus Torvalds 已提交
4060 4061 4062 4063
	if (err)
		return err;

	/*
J
James Morris 已提交
4064
	 * If a TCP or DCCP socket, check name_connect permission for the port.
L
Linus Torvalds 已提交
4065
	 */
4066 4067
	if (sksec->sclass == SECCLASS_TCP_SOCKET ||
	    sksec->sclass == SECCLASS_DCCP_SOCKET) {
4068
		struct common_audit_data ad;
4069
		struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4070 4071 4072
		struct sockaddr_in *addr4 = NULL;
		struct sockaddr_in6 *addr6 = NULL;
		unsigned short snum;
J
James Morris 已提交
4073
		u32 sid, perm;
L
Linus Torvalds 已提交
4074 4075 4076

		if (sk->sk_family == PF_INET) {
			addr4 = (struct sockaddr_in *)address;
4077
			if (addrlen < sizeof(struct sockaddr_in))
L
Linus Torvalds 已提交
4078 4079 4080 4081
				return -EINVAL;
			snum = ntohs(addr4->sin_port);
		} else {
			addr6 = (struct sockaddr_in6 *)address;
4082
			if (addrlen < SIN6_LEN_RFC2133)
L
Linus Torvalds 已提交
4083 4084 4085 4086
				return -EINVAL;
			snum = ntohs(addr6->sin6_port);
		}

P
Paul Moore 已提交
4087
		err = sel_netport_sid(sk->sk_protocol, snum, &sid);
L
Linus Torvalds 已提交
4088 4089 4090
		if (err)
			goto out;

4091
		perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
J
James Morris 已提交
4092 4093
		       TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;

4094
		ad.type = LSM_AUDIT_DATA_NET;
4095 4096 4097
		ad.u.net = &net;
		ad.u.net->dport = htons(snum);
		ad.u.net->family = sk->sk_family;
4098
		err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
L
Linus Torvalds 已提交
4099 4100 4101 4102
		if (err)
			goto out;
	}

4103 4104
	err = selinux_netlbl_socket_connect(sk, address);

L
Linus Torvalds 已提交
4105 4106 4107 4108 4109 4110
out:
	return err;
}

static int selinux_socket_listen(struct socket *sock, int backlog)
{
4111
	return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
L
Linus Torvalds 已提交
4112 4113 4114 4115 4116 4117 4118 4119
}

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

4120
	err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
L
Linus Torvalds 已提交
4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134
	if (err)
		return err;

	newisec = SOCK_INODE(newsock)->i_security;

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

	return 0;
}

static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4135
				  int size)
L
Linus Torvalds 已提交
4136
{
4137
	return sock_has_perm(current, sock->sk, SOCKET__WRITE);
L
Linus Torvalds 已提交
4138 4139 4140 4141 4142
}

static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
				  int size, int flags)
{
4143
	return sock_has_perm(current, sock->sk, SOCKET__READ);
L
Linus Torvalds 已提交
4144 4145 4146 4147
}

static int selinux_socket_getsockname(struct socket *sock)
{
4148
	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4149 4150 4151 4152
}

static int selinux_socket_getpeername(struct socket *sock)
{
4153
	return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
L
Linus Torvalds 已提交
4154 4155
}

4156
static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
L
Linus Torvalds 已提交
4157
{
4158 4159
	int err;

4160
	err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4161 4162 4163 4164
	if (err)
		return err;

	return selinux_netlbl_socket_setsockopt(sock, level, optname);
L
Linus Torvalds 已提交
4165 4166 4167 4168 4169
}

static int selinux_socket_getsockopt(struct socket *sock, int level,
				     int optname)
{
4170
	return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
L
Linus Torvalds 已提交
4171 4172 4173 4174
}

static int selinux_socket_shutdown(struct socket *sock, int how)
{
4175
	return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
L
Linus Torvalds 已提交
4176 4177
}

4178 4179
static int selinux_socket_unix_stream_connect(struct sock *sock,
					      struct sock *other,
L
Linus Torvalds 已提交
4180 4181
					      struct sock *newsk)
{
4182 4183
	struct sk_security_struct *sksec_sock = sock->sk_security;
	struct sk_security_struct *sksec_other = other->sk_security;
4184
	struct sk_security_struct *sksec_new = newsk->sk_security;
4185
	struct common_audit_data ad;
4186
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4187 4188
	int err;

4189
	ad.type = LSM_AUDIT_DATA_NET;
4190 4191
	ad.u.net = &net;
	ad.u.net->sk = other;
L
Linus Torvalds 已提交
4192

4193 4194
	err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
			   sksec_other->sclass,
L
Linus Torvalds 已提交
4195 4196 4197 4198 4199
			   UNIX_STREAM_SOCKET__CONNECTTO, &ad);
	if (err)
		return err;

	/* server child socket */
4200 4201 4202 4203 4204
	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;
4205

4206 4207 4208 4209
	/* connecting socket */
	sksec_sock->peer_sid = sksec_new->sid;

	return 0;
L
Linus Torvalds 已提交
4210 4211 4212 4213 4214
}

static int selinux_socket_unix_may_send(struct socket *sock,
					struct socket *other)
{
4215 4216
	struct sk_security_struct *ssec = sock->sk->sk_security;
	struct sk_security_struct *osec = other->sk->sk_security;
4217
	struct common_audit_data ad;
4218
	struct lsm_network_audit net = {0,};
L
Linus Torvalds 已提交
4219

4220
	ad.type = LSM_AUDIT_DATA_NET;
4221 4222
	ad.u.net = &net;
	ad.u.net->sk = other->sk;
L
Linus Torvalds 已提交
4223

4224 4225
	return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
			    &ad);
L
Linus Torvalds 已提交
4226 4227
}

4228 4229
static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
				    u32 peer_sid,
4230
				    struct common_audit_data *ad)
4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250
{
	int err;
	u32 if_sid;
	u32 node_sid;

	err = sel_netif_sid(ifindex, &if_sid);
	if (err)
		return err;
	err = avc_has_perm(peer_sid, if_sid,
			   SECCLASS_NETIF, NETIF__INGRESS, ad);
	if (err)
		return err;

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

4251
static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4252
				       u16 family)
4253
{
4254
	int err = 0;
4255 4256
	struct sk_security_struct *sksec = sk->sk_security;
	u32 sk_sid = sksec->sid;
4257
	struct common_audit_data ad;
4258
	struct lsm_network_audit net = {0,};
4259 4260
	char *addrp;

4261
	ad.type = LSM_AUDIT_DATA_NET;
4262 4263 4264
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4265 4266 4267
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
	if (err)
		return err;
L
Linus Torvalds 已提交
4268

4269
	if (selinux_secmark_enabled()) {
4270
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4271
				   PACKET__RECV, &ad);
4272 4273 4274
		if (err)
			return err;
	}
4275

4276 4277 4278 4279
	err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
	if (err)
		return err;
	err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4280

4281 4282 4283 4284 4285
	return err;
}

static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
4286
	int err;
4287
	struct sk_security_struct *sksec = sk->sk_security;
4288 4289
	u16 family = sk->sk_family;
	u32 sk_sid = sksec->sid;
4290
	struct common_audit_data ad;
4291
	struct lsm_network_audit net = {0,};
4292
	char *addrp;
4293 4294
	u8 secmark_active;
	u8 peerlbl_active;
4295 4296

	if (family != PF_INET && family != PF_INET6)
4297
		return 0;
4298 4299

	/* Handle mapped IPv4 packets arriving via IPv6 sockets */
A
Al Viro 已提交
4300
	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4301 4302
		family = PF_INET;

4303 4304 4305 4306
	/* 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. */
4307
	if (!selinux_policycap_netpeer)
4308 4309 4310
		return selinux_sock_rcv_skb_compat(sk, skb, family);

	secmark_active = selinux_secmark_enabled();
4311
	peerlbl_active = selinux_peerlbl_enabled();
4312 4313 4314
	if (!secmark_active && !peerlbl_active)
		return 0;

4315
	ad.type = LSM_AUDIT_DATA_NET;
4316 4317 4318
	ad.u.net = &net;
	ad.u.net->netif = skb->skb_iif;
	ad.u.net->family = family;
4319
	err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4320
	if (err)
4321
		return err;
4322

4323
	if (peerlbl_active) {
4324 4325 4326
		u32 peer_sid;

		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4327 4328
		if (err)
			return err;
4329
		err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4330
					       peer_sid, &ad);
4331 4332
		if (err) {
			selinux_netlbl_err(skb, err, 0);
4333
			return err;
4334
		}
4335 4336
		err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
				   PEER__RECV, &ad);
C
Chad Hanson 已提交
4337
		if (err) {
4338
			selinux_netlbl_err(skb, err, 0);
C
Chad Hanson 已提交
4339 4340
			return err;
		}
4341 4342
	}

4343
	if (secmark_active) {
4344 4345 4346 4347 4348 4349
		err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
				   PACKET__RECV, &ad);
		if (err)
			return err;
	}

4350
	return err;
L
Linus Torvalds 已提交
4351 4352
}

C
Catherine Zhang 已提交
4353 4354
static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
					    int __user *optlen, unsigned len)
L
Linus Torvalds 已提交
4355 4356 4357 4358
{
	int err = 0;
	char *scontext;
	u32 scontext_len;
4359
	struct sk_security_struct *sksec = sock->sk->sk_security;
4360
	u32 peer_sid = SECSID_NULL;
L
Linus Torvalds 已提交
4361

4362 4363
	if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
	    sksec->sclass == SECCLASS_TCP_SOCKET)
4364
		peer_sid = sksec->peer_sid;
4365 4366
	if (peer_sid == SECSID_NULL)
		return -ENOPROTOOPT;
L
Linus Torvalds 已提交
4367

C
Catherine Zhang 已提交
4368
	err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
L
Linus Torvalds 已提交
4369
	if (err)
4370
		return err;
L
Linus Torvalds 已提交
4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386

	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;
}

4387
static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
C
Catherine Zhang 已提交
4388
{
4389
	u32 peer_secid = SECSID_NULL;
4390
	u16 family;
C
Catherine Zhang 已提交
4391

4392 4393 4394 4395 4396
	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)
4397 4398 4399 4400 4401
		family = sock->sk->sk_family;
	else
		goto out;

	if (sock && family == PF_UNIX)
4402
		selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4403
	else if (skb)
4404
		selinux_skb_peerlbl_sid(skb, family, &peer_secid);
C
Catherine Zhang 已提交
4405

4406
out:
4407
	*secid = peer_secid;
4408 4409 4410
	if (peer_secid == SECSID_NULL)
		return -EINVAL;
	return 0;
C
Catherine Zhang 已提交
4411 4412
}

A
Al Viro 已提交
4413
static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
L
Linus Torvalds 已提交
4414
{
4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426
	struct sk_security_struct *sksec;

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

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

	return 0;
L
Linus Torvalds 已提交
4427 4428 4429 4430
}

static void selinux_sk_free_security(struct sock *sk)
{
4431 4432 4433 4434 4435
	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
4436 4437
}

4438
static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4439
{
4440 4441
	struct sk_security_struct *sksec = sk->sk_security;
	struct sk_security_struct *newsksec = newsk->sk_security;
4442

4443 4444 4445
	newsksec->sid = sksec->sid;
	newsksec->peer_sid = sksec->peer_sid;
	newsksec->sclass = sksec->sclass;
4446

4447
	selinux_netlbl_sk_security_reset(newsksec);
4448 4449
}

V
Venkat Yekkirala 已提交
4450
static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4451
{
4452
	if (!sk)
V
Venkat Yekkirala 已提交
4453
		*secid = SECINITSID_ANY_SOCKET;
4454 4455
	else {
		struct sk_security_struct *sksec = sk->sk_security;
4456

V
Venkat Yekkirala 已提交
4457
		*secid = sksec->sid;
4458
	}
4459 4460
}

4461
static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4462 4463 4464 4465
{
	struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
	struct sk_security_struct *sksec = sk->sk_security;

4466 4467 4468
	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
	    sk->sk_family == PF_UNIX)
		isec->sid = sksec->sid;
4469
	sksec->sclass = isec->sclass;
4470 4471
}

4472 4473
static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
				     struct request_sock *req)
4474 4475 4476
{
	struct sk_security_struct *sksec = sk->sk_security;
	int err;
4477
	u16 family = req->rsk_ops->family;
4478
	u32 connsid;
4479 4480
	u32 peersid;

4481
	err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4482 4483
	if (err)
		return err;
4484 4485 4486 4487 4488
	err = selinux_conn_sid(sksec->sid, peersid, &connsid);
	if (err)
		return err;
	req->secid = connsid;
	req->peer_secid = peersid;
4489

4490
	return selinux_netlbl_inet_conn_request(req, family);
4491 4492
}

4493 4494
static void selinux_inet_csk_clone(struct sock *newsk,
				   const struct request_sock *req)
4495 4496 4497 4498
{
	struct sk_security_struct *newsksec = newsk->sk_security;

	newsksec->sid = req->secid;
4499
	newsksec->peer_sid = req->peer_secid;
4500 4501 4502 4503
	/* 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. */
4504

P
Paul Moore 已提交
4505 4506
	/* We don't need to take any sort of lock here as we are the only
	 * thread with access to newsksec */
4507
	selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4508 4509
}

4510
static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4511
{
4512
	u16 family = sk->sk_family;
4513 4514
	struct sk_security_struct *sksec = sk->sk_security;

4515 4516 4517 4518 4519
	/* 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);
4520 4521
}

4522 4523 4524 4525 4526
static void selinux_skb_owned_by(struct sk_buff *skb, struct sock *sk)
{
	skb_set_owner_w(skb, sk);
}

4527 4528 4529 4530 4531 4532 4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544 4545 4546 4547
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);
}

4548 4549
static void selinux_req_classify_flow(const struct request_sock *req,
				      struct flowi *fl)
4550
{
4551
	fl->flowi_secid = req->secid;
4552 4553
}

4554 4555 4556 4557 4558 4559 4560 4561 4562 4563 4564 4565 4566 4567 4568 4569 4570 4571
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);
}

4572 4573 4574 4575 4576 4577 4578 4579 4580 4581 4582 4583 4584 4585 4586
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);
}

4587
static int selinux_tun_dev_attach_queue(void *security)
4588
{
4589 4590 4591 4592 4593 4594 4595 4596 4597
	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;
4598 4599 4600 4601 4602 4603 4604 4605 4606
	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 */

4607
	sksec->sid = tunsec->sid;
4608
	sksec->sclass = SECCLASS_TUN_SOCKET;
4609 4610

	return 0;
4611 4612
}

4613
static int selinux_tun_dev_open(void *security)
4614
{
4615
	struct tun_security_struct *tunsec = security;
4616 4617 4618
	u32 sid = current_sid();
	int err;

4619
	err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET,
4620 4621 4622 4623 4624 4625 4626
			   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;
4627
	tunsec->sid = sid;
4628 4629 4630 4631

	return 0;
}

L
Linus Torvalds 已提交
4632 4633 4634 4635 4636
static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
{
	int err = 0;
	u32 perm;
	struct nlmsghdr *nlh;
4637
	struct sk_security_struct *sksec = sk->sk_security;
4638

4639
	if (skb->len < NLMSG_HDRLEN) {
L
Linus Torvalds 已提交
4640 4641 4642
		err = -EINVAL;
		goto out;
	}
4643
	nlh = nlmsg_hdr(skb);
4644

4645
	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
L
Linus Torvalds 已提交
4646 4647
	if (err) {
		if (err == -EINVAL) {
4648
			audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
L
Linus Torvalds 已提交
4649 4650
				  "SELinux:  unrecognized netlink message"
				  " type=%hu for sclass=%hu\n",
4651
				  nlh->nlmsg_type, sksec->sclass);
4652
			if (!selinux_enforcing || security_get_allow_unknown())
L
Linus Torvalds 已提交
4653 4654 4655 4656 4657 4658 4659 4660 4661
				err = 0;
		}

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

4662
	err = sock_has_perm(current, sk, perm);
L
Linus Torvalds 已提交
4663 4664 4665 4666 4667 4668
out:
	return err;
}

#ifdef CONFIG_NETFILTER

4669 4670
static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
				       u16 family)
L
Linus Torvalds 已提交
4671
{
4672
	int err;
4673 4674
	char *addrp;
	u32 peer_sid;
4675
	struct common_audit_data ad;
4676
	struct lsm_network_audit net = {0,};
4677
	u8 secmark_active;
4678
	u8 netlbl_active;
4679
	u8 peerlbl_active;
4680

4681 4682
	if (!selinux_policycap_netpeer)
		return NF_ACCEPT;
4683

4684
	secmark_active = selinux_secmark_enabled();
4685
	netlbl_active = netlbl_enabled();
4686
	peerlbl_active = selinux_peerlbl_enabled();
4687 4688
	if (!secmark_active && !peerlbl_active)
		return NF_ACCEPT;
4689

4690 4691 4692
	if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
		return NF_DROP;

4693
	ad.type = LSM_AUDIT_DATA_NET;
4694 4695 4696
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4697 4698 4699
	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
		return NF_DROP;

4700 4701 4702 4703 4704
	if (peerlbl_active) {
		err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
					       peer_sid, &ad);
		if (err) {
			selinux_netlbl_err(skb, err, 1);
4705
			return NF_DROP;
4706 4707
		}
	}
4708 4709 4710 4711 4712 4713

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

4714 4715 4716 4717 4718 4719 4720 4721
	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;

4722 4723 4724 4725 4726 4727 4728 4729 4730 4731 4732 4733 4734 4735 4736 4737 4738 4739 4740 4741 4742 4743 4744
	return NF_ACCEPT;
}

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

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

4745 4746 4747
static unsigned int selinux_ip_output(struct sk_buff *skb,
				      u16 family)
{
4748
	struct sock *sk;
4749 4750 4751 4752 4753 4754 4755 4756
	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 */
4757 4758 4759 4760 4761 4762 4763 4764 4765 4766 4767 4768 4769 4770 4771 4772 4773 4774 4775 4776 4777
	sk = skb->sk;
	if (sk) {
		struct sk_security_struct *sksec;

		if (sk->sk_state == TCP_LISTEN)
			/* 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;
4778 4779 4780 4781 4782 4783 4784 4785 4786 4787 4788 4789 4790 4791 4792 4793 4794 4795
		sid = sksec->sid;
	} else
		sid = SECINITSID_KERNEL;
	if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
		return NF_DROP;

	return NF_ACCEPT;
}

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

4796 4797
static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
						int ifindex,
4798
						u16 family)
4799 4800 4801
{
	struct sock *sk = skb->sk;
	struct sk_security_struct *sksec;
4802
	struct common_audit_data ad;
4803
	struct lsm_network_audit net = {0,};
4804 4805
	char *addrp;
	u8 proto;
L
Linus Torvalds 已提交
4806

4807 4808 4809 4810
	if (sk == NULL)
		return NF_ACCEPT;
	sksec = sk->sk_security;

4811
	ad.type = LSM_AUDIT_DATA_NET;
4812 4813 4814
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4815 4816 4817
	if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
		return NF_DROP;

4818
	if (selinux_secmark_enabled())
4819
		if (avc_has_perm(sksec->sid, skb->secmark,
4820
				 SECCLASS_PACKET, PACKET__SEND, &ad))
4821
			return NF_DROP_ERR(-ECONNREFUSED);
4822

4823 4824
	if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
		return NF_DROP_ERR(-ECONNREFUSED);
4825 4826

	return NF_ACCEPT;
4827 4828
}

4829 4830
static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
					 u16 family)
4831
{
4832 4833
	u32 secmark_perm;
	u32 peer_sid;
4834
	struct sock *sk;
4835
	struct common_audit_data ad;
4836
	struct lsm_network_audit net = {0,};
4837 4838 4839
	char *addrp;
	u8 secmark_active;
	u8 peerlbl_active;
4840

4841 4842 4843 4844
	/* 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. */
4845
	if (!selinux_policycap_netpeer)
4846
		return selinux_ip_postroute_compat(skb, ifindex, family);
4847 4848 4849 4850 4851 4852 4853 4854

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

	sk = skb->sk;

4855
#ifdef CONFIG_XFRM
4856 4857 4858 4859 4860
	/* 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
4861 4862 4863 4864 4865 4866 4867 4868
	 *       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 &&
	    !(sk != NULL && sk->sk_state == TCP_LISTEN))
4869
		return NF_ACCEPT;
4870
#endif
4871

4872
	if (sk == NULL) {
4873 4874 4875 4876
		/* 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. */
4877 4878
		if (skb->skb_iif) {
			secmark_perm = PACKET__FORWARD_OUT;
4879
			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4880
				return NF_DROP;
4881 4882
		} else {
			secmark_perm = PACKET__SEND;
4883
			peer_sid = SECINITSID_KERNEL;
4884
		}
4885 4886 4887 4888 4889 4890 4891 4892 4893 4894 4895 4896 4897 4898
	} else if (sk->sk_state == TCP_LISTEN) {
		/* 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;
		struct sk_security_struct *sksec = sk->sk_security;
		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))
			return NF_DROP;
4899 4900 4901 4902 4903 4904 4905 4906 4907 4908 4909 4910 4911 4912 4913 4914 4915 4916 4917
		/* 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;
			default:
				return NF_DROP_ERR(-ECONNREFUSED);
			}
		}
4918 4919 4920
		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))
			return NF_DROP;
		secmark_perm = PACKET__SEND;
4921
	} else {
4922 4923
		/* Locally generated packet, fetch the security label from the
		 * associated socket. */
4924 4925 4926 4927
		struct sk_security_struct *sksec = sk->sk_security;
		peer_sid = sksec->sid;
		secmark_perm = PACKET__SEND;
	}
4928

4929
	ad.type = LSM_AUDIT_DATA_NET;
4930 4931 4932
	ad.u.net = &net;
	ad.u.net->netif = ifindex;
	ad.u.net->family = family;
4933
	if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4934
		return NF_DROP;
4935

4936 4937 4938
	if (secmark_active)
		if (avc_has_perm(peer_sid, skb->secmark,
				 SECCLASS_PACKET, secmark_perm, &ad))
4939
			return NF_DROP_ERR(-ECONNREFUSED);
4940 4941 4942 4943 4944 4945

	if (peerlbl_active) {
		u32 if_sid;
		u32 node_sid;

		if (sel_netif_sid(ifindex, &if_sid))
4946
			return NF_DROP;
4947 4948
		if (avc_has_perm(peer_sid, if_sid,
				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
4949
			return NF_DROP_ERR(-ECONNREFUSED);
4950 4951

		if (sel_netnode_sid(addrp, family, &node_sid))
4952
			return NF_DROP;
4953 4954
		if (avc_has_perm(peer_sid, node_sid,
				 SECCLASS_NODE, NODE__SENDTO, &ad))
4955
			return NF_DROP_ERR(-ECONNREFUSED);
4956
	}
4957

4958
	return NF_ACCEPT;
L
Linus Torvalds 已提交
4959 4960
}

4961 4962 4963 4964 4965
static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
					   struct sk_buff *skb,
					   const struct net_device *in,
					   const struct net_device *out,
					   int (*okfn)(struct sk_buff *))
L
Linus Torvalds 已提交
4966
{
4967
	return selinux_ip_postroute(skb, out->ifindex, PF_INET);
L
Linus Torvalds 已提交
4968 4969 4970
}

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4971 4972 4973 4974 4975
static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
					   struct sk_buff *skb,
					   const struct net_device *in,
					   const struct net_device *out,
					   int (*okfn)(struct sk_buff *))
L
Linus Torvalds 已提交
4976
{
4977
	return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
L
Linus Torvalds 已提交
4978 4979 4980 4981 4982 4983 4984 4985 4986
}
#endif	/* IPV6 */

#endif	/* CONFIG_NETFILTER */

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

4987
	err = cap_netlink_send(sk, skb);
L
Linus Torvalds 已提交
4988 4989 4990
	if (err)
		return err;

4991
	return selinux_nlmsg_perm(sk, skb);
L
Linus Torvalds 已提交
4992 4993 4994 4995 4996 4997 4998
}

static int ipc_alloc_security(struct task_struct *task,
			      struct kern_ipc_perm *perm,
			      u16 sclass)
{
	struct ipc_security_struct *isec;
4999
	u32 sid;
L
Linus Torvalds 已提交
5000

J
James Morris 已提交
5001
	isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
5002 5003 5004
	if (!isec)
		return -ENOMEM;

5005
	sid = task_sid(task);
L
Linus Torvalds 已提交
5006
	isec->sclass = sclass;
5007
	isec->sid = sid;
L
Linus Torvalds 已提交
5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023
	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
5024
	msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
L
Linus Torvalds 已提交
5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040 5041 5042
	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,
5043
			u32 perms)
L
Linus Torvalds 已提交
5044 5045
{
	struct ipc_security_struct *isec;
5046
	struct common_audit_data ad;
5047
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5048 5049 5050

	isec = ipc_perms->security;

5051
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5052 5053
	ad.u.ipc_id = ipc_perms->key;

5054
	return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
L
Linus Torvalds 已提交
5055 5056 5057 5058 5059 5060 5061 5062 5063 5064 5065 5066 5067 5068 5069 5070
}

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;
5071
	struct common_audit_data ad;
5072
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5073 5074 5075 5076 5077 5078 5079 5080
	int rc;

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

	isec = msq->q_perm.security;

5081
	ad.type = LSM_AUDIT_DATA_IPC;
5082
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5083

5084
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5085 5086 5087 5088 5089 5090 5091 5092 5093 5094 5095 5096 5097 5098 5099 5100
			  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;
5101
	struct common_audit_data ad;
5102
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5103 5104 5105

	isec = msq->q_perm.security;

5106
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5107 5108
	ad.u.ipc_id = msq->q_perm.key;

5109
	return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5110 5111 5112 5113 5114 5115 5116 5117
			    MSGQ__ASSOCIATE, &ad);
}

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

5118
	switch (cmd) {
L
Linus Torvalds 已提交
5119 5120 5121 5122 5123 5124 5125 5126 5127 5128 5129 5130 5131 5132 5133 5134 5135 5136
	case IPC_INFO:
	case MSG_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	case IPC_STAT:
	case MSG_STAT:
		perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
		break;
	case IPC_SET:
		perms = MSGQ__SETATTR;
		break;
	case IPC_RMID:
		perms = MSGQ__DESTROY;
		break;
	default:
		return 0;
	}

5137
	err = ipc_has_perm(&msq->q_perm, perms);
L
Linus Torvalds 已提交
5138 5139 5140 5141 5142 5143 5144
	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;
5145
	struct common_audit_data ad;
5146
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5147 5148 5149 5150 5151 5152 5153 5154 5155 5156 5157 5158 5159
	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
		 */
5160
		rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5161
					     NULL, &msec->sid);
L
Linus Torvalds 已提交
5162 5163 5164 5165
		if (rc)
			return rc;
	}

5166
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5167 5168 5169
	ad.u.ipc_id = msq->q_perm.key;

	/* Can this process write to the queue? */
5170
	rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
L
Linus Torvalds 已提交
5171 5172 5173
			  MSGQ__WRITE, &ad);
	if (!rc)
		/* Can this process send the message */
5174 5175
		rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
				  MSG__SEND, &ad);
L
Linus Torvalds 已提交
5176 5177
	if (!rc)
		/* Can the message be put in the queue? */
5178 5179
		rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
				  MSGQ__ENQUEUE, &ad);
L
Linus Torvalds 已提交
5180 5181 5182 5183 5184 5185 5186 5187 5188 5189

	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;
5190
	struct common_audit_data ad;
5191
	u32 sid = task_sid(target);
L
Linus Torvalds 已提交
5192 5193 5194 5195 5196
	int rc;

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

5197
	ad.type = LSM_AUDIT_DATA_IPC;
5198
	ad.u.ipc_id = msq->q_perm.key;
L
Linus Torvalds 已提交
5199

5200
	rc = avc_has_perm(sid, isec->sid,
L
Linus Torvalds 已提交
5201 5202
			  SECCLASS_MSGQ, MSGQ__READ, &ad);
	if (!rc)
5203
		rc = avc_has_perm(sid, msec->sid,
L
Linus Torvalds 已提交
5204 5205 5206 5207 5208 5209 5210 5211
				  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;
5212
	struct common_audit_data ad;
5213
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5214 5215 5216 5217 5218 5219 5220 5221
	int rc;

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

	isec = shp->shm_perm.security;

5222
	ad.type = LSM_AUDIT_DATA_IPC;
5223
	ad.u.ipc_id = shp->shm_perm.key;
L
Linus Torvalds 已提交
5224

5225
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241
			  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;
5242
	struct common_audit_data ad;
5243
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5244 5245 5246

	isec = shp->shm_perm.security;

5247
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5248 5249
	ad.u.ipc_id = shp->shm_perm.key;

5250
	return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
L
Linus Torvalds 已提交
5251 5252 5253 5254 5255 5256 5257 5258 5259
			    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;

5260
	switch (cmd) {
L
Linus Torvalds 已提交
5261 5262 5263 5264 5265 5266 5267 5268 5269 5270 5271 5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282
	case IPC_INFO:
	case SHM_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	case IPC_STAT:
	case SHM_STAT:
		perms = SHM__GETATTR | SHM__ASSOCIATE;
		break;
	case IPC_SET:
		perms = SHM__SETATTR;
		break;
	case SHM_LOCK:
	case SHM_UNLOCK:
		perms = SHM__LOCK;
		break;
	case IPC_RMID:
		perms = SHM__DESTROY;
		break;
	default:
		return 0;
	}

5283
	err = ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5284 5285 5286 5287 5288 5289 5290 5291 5292 5293 5294 5295 5296
	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;

5297
	return ipc_has_perm(&shp->shm_perm, perms);
L
Linus Torvalds 已提交
5298 5299 5300 5301 5302 5303
}

/* Semaphore security operations */
static int selinux_sem_alloc_security(struct sem_array *sma)
{
	struct ipc_security_struct *isec;
5304
	struct common_audit_data ad;
5305
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5306 5307 5308 5309 5310 5311 5312 5313
	int rc;

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

	isec = sma->sem_perm.security;

5314
	ad.type = LSM_AUDIT_DATA_IPC;
5315
	ad.u.ipc_id = sma->sem_perm.key;
L
Linus Torvalds 已提交
5316

5317
	rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5318 5319 5320 5321 5322 5323 5324 5325 5326 5327 5328 5329 5330 5331 5332 5333
			  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;
5334
	struct common_audit_data ad;
5335
	u32 sid = current_sid();
L
Linus Torvalds 已提交
5336 5337 5338

	isec = sma->sem_perm.security;

5339
	ad.type = LSM_AUDIT_DATA_IPC;
L
Linus Torvalds 已提交
5340 5341
	ad.u.ipc_id = sma->sem_perm.key;

5342
	return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
L
Linus Torvalds 已提交
5343 5344 5345 5346 5347 5348 5349 5350 5351
			    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;

5352
	switch (cmd) {
L
Linus Torvalds 已提交
5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 5381 5382 5383
	case IPC_INFO:
	case SEM_INFO:
		/* No specific object, just general system-wide information. */
		return task_has_system(current, SYSTEM__IPC_INFO);
	case GETPID:
	case GETNCNT:
	case GETZCNT:
		perms = SEM__GETATTR;
		break;
	case GETVAL:
	case GETALL:
		perms = SEM__READ;
		break;
	case SETVAL:
	case SETALL:
		perms = SEM__WRITE;
		break;
	case IPC_RMID:
		perms = SEM__DESTROY;
		break;
	case IPC_SET:
		perms = SEM__SETATTR;
		break;
	case IPC_STAT:
	case SEM_STAT:
		perms = SEM__GETATTR | SEM__ASSOCIATE;
		break;
	default:
		return 0;
	}

5384
	err = ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397
	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;

5398
	return ipc_has_perm(&sma->sem_perm, perms);
L
Linus Torvalds 已提交
5399 5400 5401 5402 5403 5404 5405 5406 5407 5408 5409 5410 5411 5412 5413
}

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;

5414
	return ipc_has_perm(ipcp, av);
L
Linus Torvalds 已提交
5415 5416
}

5417 5418 5419 5420 5421 5422
static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
{
	struct ipc_security_struct *isec = ipcp->security;
	*secid = isec->sid;
}

5423
static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
L
Linus Torvalds 已提交
5424 5425 5426 5427 5428 5429
{
	if (inode)
		inode_doinit_with_dentry(inode, dentry);
}

static int selinux_getprocattr(struct task_struct *p,
5430
			       char *name, char **value)
L
Linus Torvalds 已提交
5431
{
5432
	const struct task_security_struct *__tsec;
5433
	u32 sid;
L
Linus Torvalds 已提交
5434
	int error;
5435
	unsigned len;
L
Linus Torvalds 已提交
5436 5437

	if (current != p) {
5438
		error = current_has_perm(p, PROCESS__GETATTR);
L
Linus Torvalds 已提交
5439 5440 5441 5442
		if (error)
			return error;
	}

5443 5444
	rcu_read_lock();
	__tsec = __task_cred(p)->security;
L
Linus Torvalds 已提交
5445 5446

	if (!strcmp(name, "current"))
5447
		sid = __tsec->sid;
L
Linus Torvalds 已提交
5448
	else if (!strcmp(name, "prev"))
5449
		sid = __tsec->osid;
L
Linus Torvalds 已提交
5450
	else if (!strcmp(name, "exec"))
5451
		sid = __tsec->exec_sid;
L
Linus Torvalds 已提交
5452
	else if (!strcmp(name, "fscreate"))
5453
		sid = __tsec->create_sid;
5454
	else if (!strcmp(name, "keycreate"))
5455
		sid = __tsec->keycreate_sid;
5456
	else if (!strcmp(name, "sockcreate"))
5457
		sid = __tsec->sockcreate_sid;
L
Linus Torvalds 已提交
5458
	else
5459 5460
		goto invalid;
	rcu_read_unlock();
L
Linus Torvalds 已提交
5461 5462 5463 5464

	if (!sid)
		return 0;

5465 5466 5467 5468
	error = security_sid_to_context(sid, value, &len);
	if (error)
		return error;
	return len;
5469 5470 5471 5472

invalid:
	rcu_read_unlock();
	return -EINVAL;
L
Linus Torvalds 已提交
5473 5474 5475 5476 5477 5478
}

static int selinux_setprocattr(struct task_struct *p,
			       char *name, void *value, size_t size)
{
	struct task_security_struct *tsec;
R
Roland McGrath 已提交
5479
	struct task_struct *tracer;
D
David Howells 已提交
5480 5481
	struct cred *new;
	u32 sid = 0, ptsid;
L
Linus Torvalds 已提交
5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496
	int error;
	char *str = value;

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

	/*
	 * Basic control over ability to set these attributes at all.
	 * current == p, but we'll pass them separately in case the
	 * above restriction is ever removed.
	 */
	if (!strcmp(name, "exec"))
5497
		error = current_has_perm(p, PROCESS__SETEXEC);
L
Linus Torvalds 已提交
5498
	else if (!strcmp(name, "fscreate"))
5499
		error = current_has_perm(p, PROCESS__SETFSCREATE);
5500
	else if (!strcmp(name, "keycreate"))
5501
		error = current_has_perm(p, PROCESS__SETKEYCREATE);
5502
	else if (!strcmp(name, "sockcreate"))
5503
		error = current_has_perm(p, PROCESS__SETSOCKCREATE);
L
Linus Torvalds 已提交
5504
	else if (!strcmp(name, "current"))
5505
		error = current_has_perm(p, PROCESS__SETCURRENT);
L
Linus Torvalds 已提交
5506 5507 5508 5509 5510 5511 5512 5513 5514 5515 5516 5517
	else
		error = -EINVAL;
	if (error)
		return error;

	/* Obtain a SID for the context, if one was specified. */
	if (size && str[1] && str[1] != '\n') {
		if (str[size-1] == '\n') {
			str[size-1] = 0;
			size--;
		}
		error = security_context_to_sid(value, size, &sid);
5518
		if (error == -EINVAL && !strcmp(name, "fscreate")) {
5519 5520 5521 5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533
			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);

5534
				return error;
5535
			}
5536 5537 5538
			error = security_context_to_sid_force(value, size,
							      &sid);
		}
L
Linus Torvalds 已提交
5539 5540 5541 5542
		if (error)
			return error;
	}

D
David Howells 已提交
5543 5544 5545 5546
	new = prepare_creds();
	if (!new)
		return -ENOMEM;

L
Linus Torvalds 已提交
5547 5548 5549
	/* 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
5550
	   operation.  See selinux_bprm_set_creds for the execve
L
Linus Torvalds 已提交
5551 5552
	   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
5553 5554
	tsec = new->security;
	if (!strcmp(name, "exec")) {
L
Linus Torvalds 已提交
5555
		tsec->exec_sid = sid;
D
David Howells 已提交
5556
	} else if (!strcmp(name, "fscreate")) {
L
Linus Torvalds 已提交
5557
		tsec->create_sid = sid;
D
David Howells 已提交
5558
	} else if (!strcmp(name, "keycreate")) {
5559 5560
		error = may_create_key(sid, p);
		if (error)
D
David Howells 已提交
5561
			goto abort_change;
5562
		tsec->keycreate_sid = sid;
D
David Howells 已提交
5563
	} else if (!strcmp(name, "sockcreate")) {
5564
		tsec->sockcreate_sid = sid;
D
David Howells 已提交
5565 5566
	} else if (!strcmp(name, "current")) {
		error = -EINVAL;
L
Linus Torvalds 已提交
5567
		if (sid == 0)
D
David Howells 已提交
5568 5569 5570 5571
			goto abort_change;

		/* Only allow single threaded processes to change context */
		error = -EPERM;
5572
		if (!current_is_single_threaded()) {
D
David Howells 已提交
5573 5574 5575
			error = security_bounded_transition(tsec->sid, sid);
			if (error)
				goto abort_change;
5576
		}
L
Linus Torvalds 已提交
5577 5578 5579

		/* Check permissions for the transition. */
		error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5580
				     PROCESS__DYNTRANSITION, NULL);
L
Linus Torvalds 已提交
5581
		if (error)
D
David Howells 已提交
5582
			goto abort_change;
L
Linus Torvalds 已提交
5583 5584 5585

		/* Check for ptracing, and update the task SID if ok.
		   Otherwise, leave SID unchanged and fail. */
D
David Howells 已提交
5586
		ptsid = 0;
L
Linus Torvalds 已提交
5587
		task_lock(p);
5588
		tracer = ptrace_parent(p);
D
David Howells 已提交
5589 5590 5591 5592 5593 5594 5595
		if (tracer)
			ptsid = task_sid(tracer);
		task_unlock(p);

		if (tracer) {
			error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
					     PROCESS__PTRACE, NULL);
L
Linus Torvalds 已提交
5596
			if (error)
D
David Howells 已提交
5597
				goto abort_change;
L
Linus Torvalds 已提交
5598 5599
		}

D
David Howells 已提交
5600 5601 5602 5603 5604 5605 5606
		tsec->sid = sid;
	} else {
		error = -EINVAL;
		goto abort_change;
	}

	commit_creds(new);
L
Linus Torvalds 已提交
5607
	return size;
D
David Howells 已提交
5608 5609 5610 5611

abort_change:
	abort_creds(new);
	return error;
L
Linus Torvalds 已提交
5612 5613
}

5614 5615 5616 5617 5618
static int selinux_ismaclabel(const char *name)
{
	return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0);
}

5619 5620 5621 5622 5623
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
	return security_sid_to_context(secid, secdata, seclen);
}

5624
static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5625 5626 5627 5628
{
	return security_context_to_sid(secdata, seclen, secid);
}

5629 5630
static void selinux_release_secctx(char *secdata, u32 seclen)
{
5631
	kfree(secdata);
5632 5633
}

5634 5635 5636 5637 5638 5639 5640 5641 5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659
/*
 *	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;
}
5660 5661
#ifdef CONFIG_KEYS

D
David Howells 已提交
5662
static int selinux_key_alloc(struct key *k, const struct cred *cred,
5663
			     unsigned long flags)
5664
{
D
David Howells 已提交
5665
	const struct task_security_struct *tsec;
5666 5667 5668 5669 5670 5671
	struct key_security_struct *ksec;

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

D
David Howells 已提交
5672 5673 5674
	tsec = cred->security;
	if (tsec->keycreate_sid)
		ksec->sid = tsec->keycreate_sid;
5675
	else
D
David Howells 已提交
5676
		ksec->sid = tsec->sid;
5677

5678
	k->security = ksec;
5679 5680 5681 5682 5683 5684 5685 5686 5687 5688 5689 5690
	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
5691 5692
				  const struct cred *cred,
				  key_perm_t perm)
5693 5694 5695
{
	struct key *key;
	struct key_security_struct *ksec;
5696
	u32 sid;
5697 5698 5699 5700 5701 5702 5703

	/* 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
5704
	sid = cred_sid(cred);
5705 5706 5707 5708 5709

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

	return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5710 5711
}

5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724 5725
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;
}

5726 5727
#endif

L
Linus Torvalds 已提交
5728
static struct security_operations selinux_ops = {
5729 5730
	.name =				"selinux",

5731
	.ptrace_access_check =		selinux_ptrace_access_check,
5732
	.ptrace_traceme =		selinux_ptrace_traceme,
L
Linus Torvalds 已提交
5733
	.capget =			selinux_capget,
D
David Howells 已提交
5734
	.capset =			selinux_capset,
L
Linus Torvalds 已提交
5735 5736 5737 5738 5739 5740 5741 5742
	.capable =			selinux_capable,
	.quotactl =			selinux_quotactl,
	.quota_on =			selinux_quota_on,
	.syslog =			selinux_syslog,
	.vm_enough_memory =		selinux_vm_enough_memory,

	.netlink_send =			selinux_netlink_send,

5743 5744 5745
	.bprm_set_creds =		selinux_bprm_set_creds,
	.bprm_committing_creds =	selinux_bprm_committing_creds,
	.bprm_committed_creds =		selinux_bprm_committed_creds,
L
Linus Torvalds 已提交
5746 5747 5748 5749 5750
	.bprm_secureexec =		selinux_bprm_secureexec,

	.sb_alloc_security =		selinux_sb_alloc_security,
	.sb_free_security =		selinux_sb_free_security,
	.sb_copy_data =			selinux_sb_copy_data,
5751
	.sb_remount =			selinux_sb_remount,
5752
	.sb_kern_mount =		selinux_sb_kern_mount,
5753
	.sb_show_options =		selinux_sb_show_options,
L
Linus Torvalds 已提交
5754 5755 5756
	.sb_statfs =			selinux_sb_statfs,
	.sb_mount =			selinux_mount,
	.sb_umount =			selinux_umount,
5757
	.sb_set_mnt_opts =		selinux_set_mnt_opts,
5758
	.sb_clone_mnt_opts =		selinux_sb_clone_mnt_opts,
5759 5760
	.sb_parse_opts_str = 		selinux_parse_opts_str,

5761
	.dentry_init_security =		selinux_dentry_init_security,
L
Linus Torvalds 已提交
5762 5763 5764

	.inode_alloc_security =		selinux_inode_alloc_security,
	.inode_free_security =		selinux_inode_free_security,
5765
	.inode_init_security =		selinux_inode_init_security,
L
Linus Torvalds 已提交
5766 5767 5768 5769 5770 5771 5772 5773 5774 5775 5776 5777 5778 5779 5780 5781 5782 5783
	.inode_create =			selinux_inode_create,
	.inode_link =			selinux_inode_link,
	.inode_unlink =			selinux_inode_unlink,
	.inode_symlink =		selinux_inode_symlink,
	.inode_mkdir =			selinux_inode_mkdir,
	.inode_rmdir =			selinux_inode_rmdir,
	.inode_mknod =			selinux_inode_mknod,
	.inode_rename =			selinux_inode_rename,
	.inode_readlink =		selinux_inode_readlink,
	.inode_follow_link =		selinux_inode_follow_link,
	.inode_permission =		selinux_inode_permission,
	.inode_setattr =		selinux_inode_setattr,
	.inode_getattr =		selinux_inode_getattr,
	.inode_setxattr =		selinux_inode_setxattr,
	.inode_post_setxattr =		selinux_inode_post_setxattr,
	.inode_getxattr =		selinux_inode_getxattr,
	.inode_listxattr =		selinux_inode_listxattr,
	.inode_removexattr =		selinux_inode_removexattr,
5784 5785 5786
	.inode_getsecurity =		selinux_inode_getsecurity,
	.inode_setsecurity =		selinux_inode_setsecurity,
	.inode_listsecurity =		selinux_inode_listsecurity,
5787
	.inode_getsecid =		selinux_inode_getsecid,
L
Linus Torvalds 已提交
5788 5789 5790 5791 5792

	.file_permission =		selinux_file_permission,
	.file_alloc_security =		selinux_file_alloc_security,
	.file_free_security =		selinux_file_free_security,
	.file_ioctl =			selinux_file_ioctl,
5793 5794
	.mmap_file =			selinux_mmap_file,
	.mmap_addr =			selinux_mmap_addr,
L
Linus Torvalds 已提交
5795 5796 5797 5798 5799 5800 5801
	.file_mprotect =		selinux_file_mprotect,
	.file_lock =			selinux_file_lock,
	.file_fcntl =			selinux_file_fcntl,
	.file_set_fowner =		selinux_file_set_fowner,
	.file_send_sigiotask =		selinux_file_send_sigiotask,
	.file_receive =			selinux_file_receive,

5802
	.file_open =			selinux_file_open,
5803

L
Linus Torvalds 已提交
5804
	.task_create =			selinux_task_create,
5805
	.cred_alloc_blank =		selinux_cred_alloc_blank,
5806
	.cred_free =			selinux_cred_free,
D
David Howells 已提交
5807
	.cred_prepare =			selinux_cred_prepare,
5808
	.cred_transfer =		selinux_cred_transfer,
5809 5810
	.kernel_act_as =		selinux_kernel_act_as,
	.kernel_create_files_as =	selinux_kernel_create_files_as,
5811
	.kernel_module_request =	selinux_kernel_module_request,
L
Linus Torvalds 已提交
5812 5813
	.task_setpgid =			selinux_task_setpgid,
	.task_getpgid =			selinux_task_getpgid,
5814
	.task_getsid =			selinux_task_getsid,
5815
	.task_getsecid =		selinux_task_getsecid,
L
Linus Torvalds 已提交
5816
	.task_setnice =			selinux_task_setnice,
5817
	.task_setioprio =		selinux_task_setioprio,
5818
	.task_getioprio =		selinux_task_getioprio,
L
Linus Torvalds 已提交
5819 5820 5821
	.task_setrlimit =		selinux_task_setrlimit,
	.task_setscheduler =		selinux_task_setscheduler,
	.task_getscheduler =		selinux_task_getscheduler,
5822
	.task_movememory =		selinux_task_movememory,
L
Linus Torvalds 已提交
5823 5824
	.task_kill =			selinux_task_kill,
	.task_wait =			selinux_task_wait,
5825
	.task_to_inode =		selinux_task_to_inode,
L
Linus Torvalds 已提交
5826 5827

	.ipc_permission =		selinux_ipc_permission,
5828
	.ipc_getsecid =			selinux_ipc_getsecid,
L
Linus Torvalds 已提交
5829 5830 5831 5832 5833 5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845

	.msg_msg_alloc_security =	selinux_msg_msg_alloc_security,
	.msg_msg_free_security =	selinux_msg_msg_free_security,

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

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

5846 5847
	.sem_alloc_security =		selinux_sem_alloc_security,
	.sem_free_security =		selinux_sem_free_security,
L
Linus Torvalds 已提交
5848 5849 5850 5851
	.sem_associate =		selinux_sem_associate,
	.sem_semctl =			selinux_sem_semctl,
	.sem_semop =			selinux_sem_semop,

5852
	.d_instantiate =		selinux_d_instantiate,
L
Linus Torvalds 已提交
5853

5854 5855
	.getprocattr =			selinux_getprocattr,
	.setprocattr =			selinux_setprocattr,
L
Linus Torvalds 已提交
5856

5857
	.ismaclabel =			selinux_ismaclabel,
5858
	.secid_to_secctx =		selinux_secid_to_secctx,
5859
	.secctx_to_secid =		selinux_secctx_to_secid,
5860
	.release_secctx =		selinux_release_secctx,
5861 5862 5863
	.inode_notifysecctx =		selinux_inode_notifysecctx,
	.inode_setsecctx =		selinux_inode_setsecctx,
	.inode_getsecctx =		selinux_inode_getsecctx,
5864

5865
	.unix_stream_connect =		selinux_socket_unix_stream_connect,
L
Linus Torvalds 已提交
5866 5867 5868 5869 5870 5871 5872 5873 5874 5875 5876 5877 5878 5879 5880 5881
	.unix_may_send =		selinux_socket_unix_may_send,

	.socket_create =		selinux_socket_create,
	.socket_post_create =		selinux_socket_post_create,
	.socket_bind =			selinux_socket_bind,
	.socket_connect =		selinux_socket_connect,
	.socket_listen =		selinux_socket_listen,
	.socket_accept =		selinux_socket_accept,
	.socket_sendmsg =		selinux_socket_sendmsg,
	.socket_recvmsg =		selinux_socket_recvmsg,
	.socket_getsockname =		selinux_socket_getsockname,
	.socket_getpeername =		selinux_socket_getpeername,
	.socket_getsockopt =		selinux_socket_getsockopt,
	.socket_setsockopt =		selinux_socket_setsockopt,
	.socket_shutdown =		selinux_socket_shutdown,
	.socket_sock_rcv_skb =		selinux_socket_sock_rcv_skb,
C
Catherine Zhang 已提交
5882 5883
	.socket_getpeersec_stream =	selinux_socket_getpeersec_stream,
	.socket_getpeersec_dgram =	selinux_socket_getpeersec_dgram,
L
Linus Torvalds 已提交
5884 5885
	.sk_alloc_security =		selinux_sk_alloc_security,
	.sk_free_security =		selinux_sk_free_security,
5886
	.sk_clone_security =		selinux_sk_clone_security,
5887
	.sk_getsecid =			selinux_sk_getsecid,
5888 5889 5890
	.sock_graft =			selinux_sock_graft,
	.inet_conn_request =		selinux_inet_conn_request,
	.inet_csk_clone =		selinux_inet_csk_clone,
5891
	.inet_conn_established =	selinux_inet_conn_established,
5892 5893 5894
	.secmark_relabel_packet =	selinux_secmark_relabel_packet,
	.secmark_refcount_inc =		selinux_secmark_refcount_inc,
	.secmark_refcount_dec =		selinux_secmark_refcount_dec,
5895
	.req_classify_flow =		selinux_req_classify_flow,
5896 5897
	.tun_dev_alloc_security =	selinux_tun_dev_alloc_security,
	.tun_dev_free_security =	selinux_tun_dev_free_security,
5898
	.tun_dev_create =		selinux_tun_dev_create,
5899
	.tun_dev_attach_queue =		selinux_tun_dev_attach_queue,
5900
	.tun_dev_attach =		selinux_tun_dev_attach,
5901
	.tun_dev_open =			selinux_tun_dev_open,
5902
	.skb_owned_by =			selinux_skb_owned_by,
5903 5904 5905 5906 5907

#ifdef CONFIG_SECURITY_NETWORK_XFRM
	.xfrm_policy_alloc_security =	selinux_xfrm_policy_alloc,
	.xfrm_policy_clone_security =	selinux_xfrm_policy_clone,
	.xfrm_policy_free_security =	selinux_xfrm_policy_free,
C
Catherine Zhang 已提交
5908
	.xfrm_policy_delete_security =	selinux_xfrm_policy_delete,
5909 5910
	.xfrm_state_alloc =		selinux_xfrm_state_alloc,
	.xfrm_state_alloc_acquire =	selinux_xfrm_state_alloc_acquire,
5911
	.xfrm_state_free_security =	selinux_xfrm_state_free,
C
Catherine Zhang 已提交
5912
	.xfrm_state_delete_security =	selinux_xfrm_state_delete,
5913
	.xfrm_policy_lookup =		selinux_xfrm_policy_lookup,
5914 5915
	.xfrm_state_pol_flow_match =	selinux_xfrm_state_pol_flow_match,
	.xfrm_decode_session =		selinux_xfrm_decode_session,
L
Linus Torvalds 已提交
5916
#endif
5917 5918

#ifdef CONFIG_KEYS
5919 5920 5921
	.key_alloc =			selinux_key_alloc,
	.key_free =			selinux_key_free,
	.key_permission =		selinux_key_permission,
5922
	.key_getsecurity =		selinux_key_getsecurity,
5923
#endif
5924 5925 5926 5927 5928 5929 5930

#ifdef CONFIG_AUDIT
	.audit_rule_init =		selinux_audit_rule_init,
	.audit_rule_known =		selinux_audit_rule_known,
	.audit_rule_match =		selinux_audit_rule_match,
	.audit_rule_free =		selinux_audit_rule_free,
#endif
L
Linus Torvalds 已提交
5931 5932 5933 5934
};

static __init int selinux_init(void)
{
5935 5936 5937 5938 5939
	if (!security_module_enable(&selinux_ops)) {
		selinux_enabled = 0;
		return 0;
	}

L
Linus Torvalds 已提交
5940 5941 5942 5943 5944 5945 5946 5947
	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
5948
	cred_init_security();
L
Linus Torvalds 已提交
5949

5950 5951
	default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);

5952 5953
	sel_inode_cache = kmem_cache_create("selinux_inode_security",
					    sizeof(struct inode_security_struct),
5954
					    0, SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
5955 5956
	avc_init();

5957
	if (register_security(&selinux_ops))
L
Linus Torvalds 已提交
5958 5959
		panic("SELinux: Unable to register with kernel.\n");

5960
	if (selinux_enforcing)
5961
		printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
5962
	else
5963
		printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
5964

L
Linus Torvalds 已提交
5965 5966 5967
	return 0;
}

5968 5969 5970 5971 5972
static void delayed_superblock_init(struct super_block *sb, void *unused)
{
	superblock_doinit(sb, NULL);
}

L
Linus Torvalds 已提交
5973 5974
void selinux_complete_init(void)
{
5975
	printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
L
Linus Torvalds 已提交
5976 5977

	/* Set up any superblocks initialized prior to the policy load. */
5978
	printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
5979
	iterate_supers(delayed_superblock_init, NULL);
L
Linus Torvalds 已提交
5980 5981 5982 5983 5984 5985
}

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

5986
#if defined(CONFIG_NETFILTER)
L
Linus Torvalds 已提交
5987

5988 5989 5990 5991
static struct nf_hook_ops selinux_ipv4_ops[] = {
	{
		.hook =		selinux_ipv4_postroute,
		.owner =	THIS_MODULE,
5992
		.pf =		NFPROTO_IPV4,
5993 5994 5995 5996 5997 5998
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv4_forward,
		.owner =	THIS_MODULE,
5999
		.pf =		NFPROTO_IPV4,
6000 6001
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
6002 6003 6004 6005
	},
	{
		.hook =		selinux_ipv4_output,
		.owner =	THIS_MODULE,
6006
		.pf =		NFPROTO_IPV4,
6007 6008
		.hooknum =	NF_INET_LOCAL_OUT,
		.priority =	NF_IP_PRI_SELINUX_FIRST,
6009
	}
L
Linus Torvalds 已提交
6010 6011 6012 6013
};

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

6014 6015 6016 6017
static struct nf_hook_ops selinux_ipv6_ops[] = {
	{
		.hook =		selinux_ipv6_postroute,
		.owner =	THIS_MODULE,
6018
		.pf =		NFPROTO_IPV6,
6019 6020 6021 6022 6023 6024
		.hooknum =	NF_INET_POST_ROUTING,
		.priority =	NF_IP6_PRI_SELINUX_LAST,
	},
	{
		.hook =		selinux_ipv6_forward,
		.owner =	THIS_MODULE,
6025
		.pf =		NFPROTO_IPV6,
6026 6027 6028
		.hooknum =	NF_INET_FORWARD,
		.priority =	NF_IP6_PRI_SELINUX_FIRST,
	}
L
Linus Torvalds 已提交
6029 6030 6031 6032 6033 6034 6035 6036 6037 6038
};

#endif	/* IPV6 */

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

	if (!selinux_enabled)
		goto out;
6039 6040 6041

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

6042 6043 6044
	err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
	if (err)
		panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
L
Linus Torvalds 已提交
6045 6046

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
6047 6048 6049
	err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
	if (err)
		panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
L
Linus Torvalds 已提交
6050
#endif	/* IPV6 */
6051

L
Linus Torvalds 已提交
6052 6053 6054 6055 6056 6057 6058 6059 6060
out:
	return err;
}

__initcall(selinux_nf_ip_init);

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
static void selinux_nf_ip_exit(void)
{
6061
	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
L
Linus Torvalds 已提交
6062

6063
	nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
L
Linus Torvalds 已提交
6064
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
6065
	nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
L
Linus Torvalds 已提交
6066 6067 6068 6069
#endif	/* IPV6 */
}
#endif

6070
#else /* CONFIG_NETFILTER */
L
Linus Torvalds 已提交
6071 6072 6073 6074 6075

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
#define selinux_nf_ip_exit()
#endif

6076
#endif /* CONFIG_NETFILTER */
L
Linus Torvalds 已提交
6077 6078

#ifdef CONFIG_SECURITY_SELINUX_DISABLE
6079 6080
static int selinux_disabled;

L
Linus Torvalds 已提交
6081 6082 6083 6084 6085 6086 6087 6088 6089 6090 6091 6092 6093 6094 6095
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;
6096
	selinux_enabled = 0;
L
Linus Torvalds 已提交
6097

6098
	reset_security_ops();
L
Linus Torvalds 已提交
6099

6100 6101 6102
	/* Try to destroy the avc node cache */
	avc_disable();

L
Linus Torvalds 已提交
6103 6104 6105 6106 6107 6108 6109 6110 6111
	/* Unregister netfilter hooks. */
	selinux_nf_ip_exit();

	/* Unregister selinuxfs. */
	exit_sel_fs();

	return 0;
}
#endif