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[PATCH] SELinux: convert sbsec semaphore to a mutex
[net-next-2.6.git] / security / selinux / hooks.c
CommitLineData
1da177e4
LT		 1/*
2 * NSA Security-Enhanced Linux (SELinux) security module
3 *
4 * This file contains the SELinux hook function implementations.
5 *
6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil>
7 * Chris Vance, <cvance@nai.com>
8 * Wayne Salamon, <wsalamon@nai.com>
9 * James Morris <jmorris@redhat.com>
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12 * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
13 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
14 * <dgoeddel@trustedcs.com>
7420ed23
VY		 15 * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
16 * Paul Moore, <paul.moore@hp.com>
1da177e4
LT		 17 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License version 2,
20 * as published by the Free Software Foundation.
21 */
22
1da177e4
LT		 23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/kernel.h>
26#include <linux/ptrace.h>
27#include <linux/errno.h>
28#include <linux/sched.h>
29#include <linux/security.h>
30#include <linux/xattr.h>
31#include <linux/capability.h>
32#include <linux/unistd.h>
33#include <linux/mm.h>
34#include <linux/mman.h>
35#include <linux/slab.h>
36#include <linux/pagemap.h>
37#include <linux/swap.h>
38#include <linux/smp_lock.h>
39#include <linux/spinlock.h>
40#include <linux/syscalls.h>
41#include <linux/file.h>
42#include <linux/namei.h>
43#include <linux/mount.h>
44#include <linux/ext2_fs.h>
45#include <linux/proc_fs.h>
46#include <linux/kd.h>
47#include <linux/netfilter_ipv4.h>
48#include <linux/netfilter_ipv6.h>
49#include <linux/tty.h>
50#include <net/icmp.h>
51#include <net/ip.h> /* for sysctl_local_port_range[] */
52#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
53#include <asm/uaccess.h>
1da177e4
LT		 54#include <asm/ioctls.h>
55#include <linux/bitops.h>
56#include <linux/interrupt.h>
57#include <linux/netdevice.h> /* for network interface checks */
58#include <linux/netlink.h>
59#include <linux/tcp.h>
60#include <linux/udp.h>
61#include <linux/quota.h>
62#include <linux/un.h> /* for Unix socket types */
63#include <net/af_unix.h> /* for Unix socket types */
64#include <linux/parser.h>
65#include <linux/nfs_mount.h>
66#include <net/ipv6.h>
67#include <linux/hugetlb.h>
68#include <linux/personality.h>
69#include <linux/sysctl.h>
70#include <linux/audit.h>
6931dfc9 71#include <linux/string.h>
877ce7c1 72#include <linux/selinux.h>
23970741 73#include <linux/mutex.h>
1da177e4
LT		 74
75#include "avc.h"
76#include "objsec.h"
77#include "netif.h"
d28d1e08 78#include "xfrm.h"
7420ed23 79#include "selinux_netlabel.h"
1da177e4
LT		 80
81#define XATTR_SELINUX_SUFFIX "selinux"
82#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
83
84extern unsigned int policydb_loaded_version;
85extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
4e5ab4cb 86extern int selinux_compat_net;
1da177e4
LT		 87
88#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
89int selinux_enforcing = 0;
90
91static int __init enforcing_setup(char *str)
92{
93 selinux_enforcing = simple_strtol(str,NULL,0);
94 return 1;
95}
96__setup("enforcing=", enforcing_setup);
97#endif
98
99#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
100int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
101
102static int __init selinux_enabled_setup(char *str)
103{
104 selinux_enabled = simple_strtol(str, NULL, 0);
105 return 1;
106}
107__setup("selinux=", selinux_enabled_setup);
30d55280
SS		 108#else
109int selinux_enabled = 1;
1da177e4
LT		 110#endif
111
112/* Original (dummy) security module. */
113static struct security_operations *original_ops = NULL;
114
115/* Minimal support for a secondary security module,
116 just to allow the use of the dummy or capability modules.
117 The owlsm module can alternatively be used as a secondary
118 module as long as CONFIG_OWLSM_FD is not enabled. */
119static struct security_operations *secondary_ops = NULL;
120
121/* Lists of inode and superblock security structures initialized
122 before the policy was loaded. */
123static LIST_HEAD(superblock_security_head);
124static DEFINE_SPINLOCK(sb_security_lock);
125
7cae7e26
JM		 126static kmem_cache_t *sel_inode_cache;
127
8c8570fb
DK		 128/* Return security context for a given sid or just the context
129 length if the buffer is null or length is 0 */
130static int selinux_getsecurity(u32 sid, void *buffer, size_t size)
131{
132 char *context;
133 unsigned len;
134 int rc;
135
136 rc = security_sid_to_context(sid, &context, &len);
137 if (rc)
138 return rc;
139
140 if (!buffer || !size)
141 goto getsecurity_exit;
142
143 if (size < len) {
144 len = -ERANGE;
145 goto getsecurity_exit;
146 }
147 memcpy(buffer, context, len);
148
149getsecurity_exit:
150 kfree(context);
151 return len;
152}
153
1da177e4
LT		 154/* Allocate and free functions for each kind of security blob. */
155
156static int task_alloc_security(struct task_struct *task)
157{
158 struct task_security_struct *tsec;
159
89d155ef 160 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4
LT		 161 if (!tsec)
162 return -ENOMEM;
163
1da177e4
LT		 164 tsec->task = task;
165 tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
166 task->security = tsec;
167
168 return 0;
169}
170
171static void task_free_security(struct task_struct *task)
172{
173 struct task_security_struct *tsec = task->security;
1da177e4
LT		 174 task->security = NULL;
175 kfree(tsec);
176}
177
178static int inode_alloc_security(struct inode *inode)
179{
180 struct task_security_struct *tsec = current->security;
181 struct inode_security_struct *isec;
182
7cae7e26 183 isec = kmem_cache_alloc(sel_inode_cache, SLAB_KERNEL);
1da177e4
LT		 184 if (!isec)
185 return -ENOMEM;
186
7cae7e26 187 memset(isec, 0, sizeof(*isec));
23970741 188 mutex_init(&isec->lock);
1da177e4 189 INIT_LIST_HEAD(&isec->list);
1da177e4
LT		 190 isec->inode = inode;
191 isec->sid = SECINITSID_UNLABELED;
192 isec->sclass = SECCLASS_FILE;
9ac49d22 193 isec->task_sid = tsec->sid;
1da177e4
LT		 194 inode->i_security = isec;
195
196 return 0;
197}
198
199static void inode_free_security(struct inode *inode)
200{
201 struct inode_security_struct *isec = inode->i_security;
202 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
203
1da177e4
LT		 204 spin_lock(&sbsec->isec_lock);
205 if (!list_empty(&isec->list))
206 list_del_init(&isec->list);
207 spin_unlock(&sbsec->isec_lock);
208
209 inode->i_security = NULL;
7cae7e26 210 kmem_cache_free(sel_inode_cache, isec);
1da177e4
LT		 211}
212
213static int file_alloc_security(struct file *file)
214{
215 struct task_security_struct *tsec = current->security;
216 struct file_security_struct *fsec;
217
26d2a4be 218 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
1da177e4
LT		 219 if (!fsec)
220 return -ENOMEM;
221
1da177e4 222 fsec->file = file;
9ac49d22
SS		 223 fsec->sid = tsec->sid;
224 fsec->fown_sid = tsec->sid;
1da177e4
LT		 225 file->f_security = fsec;
226
227 return 0;
228}
229
230static void file_free_security(struct file *file)
231{
232 struct file_security_struct *fsec = file->f_security;
1da177e4
LT		 233 file->f_security = NULL;
234 kfree(fsec);
235}
236
237static int superblock_alloc_security(struct super_block *sb)
238{
239 struct superblock_security_struct *sbsec;
240
89d155ef 241 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT		 242 if (!sbsec)
243 return -ENOMEM;
244
bc7e982b 245 mutex_init(&sbsec->lock);
1da177e4
LT		 246 INIT_LIST_HEAD(&sbsec->list);
247 INIT_LIST_HEAD(&sbsec->isec_head);
248 spin_lock_init(&sbsec->isec_lock);
1da177e4
LT		 249 sbsec->sb = sb;
250 sbsec->sid = SECINITSID_UNLABELED;
251 sbsec->def_sid = SECINITSID_FILE;
c312feb2 252 sbsec->mntpoint_sid = SECINITSID_UNLABELED;
1da177e4
LT		 253 sb->s_security = sbsec;
254
255 return 0;
256}
257
258static void superblock_free_security(struct super_block *sb)
259{
260 struct superblock_security_struct *sbsec = sb->s_security;
261
1da177e4
LT		 262 spin_lock(&sb_security_lock);
263 if (!list_empty(&sbsec->list))
264 list_del_init(&sbsec->list);
265 spin_unlock(&sb_security_lock);
266
267 sb->s_security = NULL;
268 kfree(sbsec);
269}
270
7d877f3b 271static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
1da177e4
LT		 272{
273 struct sk_security_struct *ssec;
274
89d155ef 275 ssec = kzalloc(sizeof(*ssec), priority);
1da177e4
LT		 276 if (!ssec)
277 return -ENOMEM;
278
1da177e4
LT		 279 ssec->sk = sk;
280 ssec->peer_sid = SECINITSID_UNLABELED;
892c141e 281 ssec->sid = SECINITSID_UNLABELED;
1da177e4
LT		 282 sk->sk_security = ssec;
283
99f59ed0
PM		 284 selinux_netlbl_sk_security_init(ssec, family);
285
1da177e4
LT		 286 return 0;
287}
288
289static void sk_free_security(struct sock *sk)
290{
291 struct sk_security_struct *ssec = sk->sk_security;
292
1da177e4
LT		 293 sk->sk_security = NULL;
294 kfree(ssec);
295}
1da177e4
LT		 296
297/* The security server must be initialized before
298 any labeling or access decisions can be provided. */
299extern int ss_initialized;
300
301/* The file system's label must be initialized prior to use. */
302
303static char *labeling_behaviors[6] = {
304 "uses xattr",
305 "uses transition SIDs",
306 "uses task SIDs",
307 "uses genfs_contexts",
308 "not configured for labeling",
309 "uses mountpoint labeling",
310};
311
312static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
313
314static inline int inode_doinit(struct inode *inode)
315{
316 return inode_doinit_with_dentry(inode, NULL);
317}
318
319enum {
320 Opt_context = 1,
321 Opt_fscontext = 2,
322 Opt_defcontext = 4,
0808925e 323 Opt_rootcontext = 8,
1da177e4
LT		 324};
325
326static match_table_t tokens = {
327 {Opt_context, "context=%s"},
328 {Opt_fscontext, "fscontext=%s"},
329 {Opt_defcontext, "defcontext=%s"},
0808925e 330 {Opt_rootcontext, "rootcontext=%s"},
1da177e4
LT		 331};
332
333#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
334
c312feb2
EP		 335static int may_context_mount_sb_relabel(u32 sid,
336 struct superblock_security_struct *sbsec,
337 struct task_security_struct *tsec)
338{
339 int rc;
340
341 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
342 FILESYSTEM__RELABELFROM, NULL);
343 if (rc)
344 return rc;
345
346 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
347 FILESYSTEM__RELABELTO, NULL);
348 return rc;
349}
350
0808925e
EP		 351static int may_context_mount_inode_relabel(u32 sid,
352 struct superblock_security_struct *sbsec,
353 struct task_security_struct *tsec)
354{
355 int rc;
356 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
357 FILESYSTEM__RELABELFROM, NULL);
358 if (rc)
359 return rc;
360
361 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
362 FILESYSTEM__ASSOCIATE, NULL);
363 return rc;
364}
365
1da177e4
LT		 366static int try_context_mount(struct super_block *sb, void *data)
367{
368 char *context = NULL, *defcontext = NULL;
0808925e 369 char *fscontext = NULL, *rootcontext = NULL;
1da177e4
LT		 370 const char *name;
371 u32 sid;
372 int alloc = 0, rc = 0, seen = 0;
373 struct task_security_struct *tsec = current->security;
374 struct superblock_security_struct *sbsec = sb->s_security;
375
376 if (!data)
377 goto out;
378
379 name = sb->s_type->name;
380
381 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
382
383 /* NFS we understand. */
384 if (!strcmp(name, "nfs")) {
385 struct nfs_mount_data *d = data;
386
387 if (d->version < NFS_MOUNT_VERSION)
388 goto out;
389
390 if (d->context[0]) {
391 context = d->context;
392 seen |= Opt_context;
393 }
394 } else
395 goto out;
396
397 } else {
398 /* Standard string-based options. */
399 char *p, *options = data;
400
401 while ((p = strsep(&options, ",")) != NULL) {
402 int token;
403 substring_t args[MAX_OPT_ARGS];
404
405 if (!*p)
406 continue;
407
408 token = match_token(p, tokens, args);
409
410 switch (token) {
411 case Opt_context:
c312feb2 412 if (seen & (Opt_context|Opt_defcontext)) {
1da177e4
LT		 413 rc = -EINVAL;
414 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
415 goto out_free;
416 }
417 context = match_strdup(&args[0]);
418 if (!context) {
419 rc = -ENOMEM;
420 goto out_free;
421 }
422 if (!alloc)
423 alloc = 1;
424 seen |= Opt_context;
425 break;
426
427 case Opt_fscontext:
c312feb2 428 if (seen & Opt_fscontext) {
1da177e4
LT		 429 rc = -EINVAL;
430 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
431 goto out_free;
432 }
c312feb2
EP		 433 fscontext = match_strdup(&args[0]);
434 if (!fscontext) {
1da177e4
LT		 435 rc = -ENOMEM;
436 goto out_free;
437 }
438 if (!alloc)
439 alloc = 1;
440 seen |= Opt_fscontext;
441 break;
442
0808925e
EP		 443 case Opt_rootcontext:
444 if (seen & Opt_rootcontext) {
445 rc = -EINVAL;
446 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
447 goto out_free;
448 }
449 rootcontext = match_strdup(&args[0]);
450 if (!rootcontext) {
451 rc = -ENOMEM;
452 goto out_free;
453 }
454 if (!alloc)
455 alloc = 1;
456 seen |= Opt_rootcontext;
457 break;
458
1da177e4
LT		 459 case Opt_defcontext:
460 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
461 rc = -EINVAL;
462 printk(KERN_WARNING "SELinux: "
463 "defcontext option is invalid "
464 "for this filesystem type\n");
465 goto out_free;
466 }
467 if (seen & (Opt_context|Opt_defcontext)) {
468 rc = -EINVAL;
469 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
470 goto out_free;
471 }
472 defcontext = match_strdup(&args[0]);
473 if (!defcontext) {
474 rc = -ENOMEM;
475 goto out_free;
476 }
477 if (!alloc)
478 alloc = 1;
479 seen |= Opt_defcontext;
480 break;
481
482 default:
483 rc = -EINVAL;
484 printk(KERN_WARNING "SELinux: unknown mount "
485 "option\n");
486 goto out_free;
487
488 }
489 }
490 }
491
492 if (!seen)
493 goto out;
494
c312feb2
EP		 495 /* sets the context of the superblock for the fs being mounted. */
496 if (fscontext) {
497 rc = security_context_to_sid(fscontext, strlen(fscontext), &sid);
1da177e4
LT		 498 if (rc) {
499 printk(KERN_WARNING "SELinux: security_context_to_sid"
500 "(%s) failed for (dev %s, type %s) errno=%d\n",
c312feb2 501 fscontext, sb->s_id, name, rc);
1da177e4
LT		 502 goto out_free;
503 }
504
c312feb2 505 rc = may_context_mount_sb_relabel(sid, sbsec, tsec);
1da177e4
LT		 506 if (rc)
507 goto out_free;
508
c312feb2
EP		 509 sbsec->sid = sid;
510 }
511
512 /*
513 * Switch to using mount point labeling behavior.
514 * sets the label used on all file below the mountpoint, and will set
515 * the superblock context if not already set.
516 */
517 if (context) {
518 rc = security_context_to_sid(context, strlen(context), &sid);
519 if (rc) {
520 printk(KERN_WARNING "SELinux: security_context_to_sid"
521 "(%s) failed for (dev %s, type %s) errno=%d\n",
522 context, sb->s_id, name, rc);
523 goto out_free;
524 }
525
b04ea3ce
EP		 526 if (!fscontext) {
527 rc = may_context_mount_sb_relabel(sid, sbsec, tsec);
528 if (rc)
529 goto out_free;
c312feb2 530 sbsec->sid = sid;
b04ea3ce
EP		 531 } else {
532 rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
533 if (rc)
534 goto out_free;
535 }
c312feb2 536 sbsec->mntpoint_sid = sid;
1da177e4 537
c312feb2 538 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
1da177e4
LT		 539 }
540
0808925e
EP		 541 if (rootcontext) {
542 struct inode *inode = sb->s_root->d_inode;
543 struct inode_security_struct *isec = inode->i_security;
544 rc = security_context_to_sid(rootcontext, strlen(rootcontext), &sid);
545 if (rc) {
546 printk(KERN_WARNING "SELinux: security_context_to_sid"
547 "(%s) failed for (dev %s, type %s) errno=%d\n",
548 rootcontext, sb->s_id, name, rc);
549 goto out_free;
550 }
551
552 rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
553 if (rc)
554 goto out_free;
555
556 isec->sid = sid;
557 isec->initialized = 1;
558 }
559
1da177e4
LT		 560 if (defcontext) {
561 rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
562 if (rc) {
563 printk(KERN_WARNING "SELinux: security_context_to_sid"
564 "(%s) failed for (dev %s, type %s) errno=%d\n",
565 defcontext, sb->s_id, name, rc);
566 goto out_free;
567 }
568
569 if (sid == sbsec->def_sid)
570 goto out_free;
571
0808925e 572 rc = may_context_mount_inode_relabel(sid, sbsec, tsec);
1da177e4
LT		 573 if (rc)
574 goto out_free;
575
576 sbsec->def_sid = sid;
577 }
578
579out_free:
580 if (alloc) {
581 kfree(context);
582 kfree(defcontext);
c312feb2 583 kfree(fscontext);
0808925e 584 kfree(rootcontext);
1da177e4
LT		 585 }
586out:
587 return rc;
588}
589
590static int superblock_doinit(struct super_block *sb, void *data)
591{
592 struct superblock_security_struct *sbsec = sb->s_security;
593 struct dentry *root = sb->s_root;
594 struct inode *inode = root->d_inode;
595 int rc = 0;
596
bc7e982b 597 mutex_lock(&sbsec->lock);
1da177e4
LT		 598 if (sbsec->initialized)
599 goto out;
600
601 if (!ss_initialized) {
602 /* Defer initialization until selinux_complete_init,
603 after the initial policy is loaded and the security
604 server is ready to handle calls. */
605 spin_lock(&sb_security_lock);
606 if (list_empty(&sbsec->list))
607 list_add(&sbsec->list, &superblock_security_head);
608 spin_unlock(&sb_security_lock);
609 goto out;
610 }
611
612 /* Determine the labeling behavior to use for this filesystem type. */
613 rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
614 if (rc) {
615 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
616 __FUNCTION__, sb->s_type->name, rc);
617 goto out;
618 }
619
620 rc = try_context_mount(sb, data);
621 if (rc)
622 goto out;
623
624 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
625 /* Make sure that the xattr handler exists and that no
626 error other than -ENODATA is returned by getxattr on
627 the root directory. -ENODATA is ok, as this may be
628 the first boot of the SELinux kernel before we have
629 assigned xattr values to the filesystem. */
630 if (!inode->i_op->getxattr) {
631 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
632 "xattr support\n", sb->s_id, sb->s_type->name);
633 rc = -EOPNOTSUPP;
634 goto out;
635 }
636 rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
637 if (rc < 0 && rc != -ENODATA) {
638 if (rc == -EOPNOTSUPP)
639 printk(KERN_WARNING "SELinux: (dev %s, type "
640 "%s) has no security xattr handler\n",
641 sb->s_id, sb->s_type->name);
642 else
643 printk(KERN_WARNING "SELinux: (dev %s, type "
644 "%s) getxattr errno %d\n", sb->s_id,
645 sb->s_type->name, -rc);
646 goto out;
647 }
648 }
649
650 if (strcmp(sb->s_type->name, "proc") == 0)
651 sbsec->proc = 1;
652
653 sbsec->initialized = 1;
654
655 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
656 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
657 sb->s_id, sb->s_type->name);
658 }
659 else {
660 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
661 sb->s_id, sb->s_type->name,
662 labeling_behaviors[sbsec->behavior-1]);
663 }
664
665 /* Initialize the root inode. */
666 rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
667
668 /* Initialize any other inodes associated with the superblock, e.g.
669 inodes created prior to initial policy load or inodes created
670 during get_sb by a pseudo filesystem that directly
671 populates itself. */
672 spin_lock(&sbsec->isec_lock);
673next_inode:
674 if (!list_empty(&sbsec->isec_head)) {
675 struct inode_security_struct *isec =
676 list_entry(sbsec->isec_head.next,
677 struct inode_security_struct, list);
678 struct inode *inode = isec->inode;
679 spin_unlock(&sbsec->isec_lock);
680 inode = igrab(inode);
681 if (inode) {
682 if (!IS_PRIVATE (inode))
683 inode_doinit(inode);
684 iput(inode);
685 }
686 spin_lock(&sbsec->isec_lock);
687 list_del_init(&isec->list);
688 goto next_inode;
689 }
690 spin_unlock(&sbsec->isec_lock);
691out:
bc7e982b 692 mutex_unlock(&sbsec->lock);
1da177e4
LT		 693 return rc;
694}
695
696static inline u16 inode_mode_to_security_class(umode_t mode)
697{
698 switch (mode & S_IFMT) {
699 case S_IFSOCK:
700 return SECCLASS_SOCK_FILE;
701 case S_IFLNK:
702 return SECCLASS_LNK_FILE;
703 case S_IFREG:
704 return SECCLASS_FILE;
705 case S_IFBLK:
706 return SECCLASS_BLK_FILE;
707 case S_IFDIR:
708 return SECCLASS_DIR;
709 case S_IFCHR:
710 return SECCLASS_CHR_FILE;
711 case S_IFIFO:
712 return SECCLASS_FIFO_FILE;
713
714 }
715
716 return SECCLASS_FILE;
717}
718
13402580
JM		 719static inline int default_protocol_stream(int protocol)
720{
721 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
722}
723
724static inline int default_protocol_dgram(int protocol)
725{
726 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
727}
728
1da177e4
LT		 729static inline u16 socket_type_to_security_class(int family, int type, int protocol)
730{
731 switch (family) {
732 case PF_UNIX:
733 switch (type) {
734 case SOCK_STREAM:
735 case SOCK_SEQPACKET:
736 return SECCLASS_UNIX_STREAM_SOCKET;
737 case SOCK_DGRAM:
738 return SECCLASS_UNIX_DGRAM_SOCKET;
739 }
740 break;
741 case PF_INET:
742 case PF_INET6:
743 switch (type) {
744 case SOCK_STREAM:
13402580
JM		 745 if (default_protocol_stream(protocol))
746 return SECCLASS_TCP_SOCKET;
747 else
748 return SECCLASS_RAWIP_SOCKET;
1da177e4 749 case SOCK_DGRAM:
13402580
JM		 750 if (default_protocol_dgram(protocol))
751 return SECCLASS_UDP_SOCKET;
752 else
753 return SECCLASS_RAWIP_SOCKET;
754 default:
1da177e4
LT		 755 return SECCLASS_RAWIP_SOCKET;
756 }
757 break;
758 case PF_NETLINK:
759 switch (protocol) {
760 case NETLINK_ROUTE:
761 return SECCLASS_NETLINK_ROUTE_SOCKET;
762 case NETLINK_FIREWALL:
763 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 764 case NETLINK_INET_DIAG:
1da177e4
LT		 765 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
766 case NETLINK_NFLOG:
767 return SECCLASS_NETLINK_NFLOG_SOCKET;
768 case NETLINK_XFRM:
769 return SECCLASS_NETLINK_XFRM_SOCKET;
770 case NETLINK_SELINUX:
771 return SECCLASS_NETLINK_SELINUX_SOCKET;
772 case NETLINK_AUDIT:
773 return SECCLASS_NETLINK_AUDIT_SOCKET;
774 case NETLINK_IP6_FW:
775 return SECCLASS_NETLINK_IP6FW_SOCKET;
776 case NETLINK_DNRTMSG:
777 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM		 778 case NETLINK_KOBJECT_UEVENT:
779 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT		 780 default:
781 return SECCLASS_NETLINK_SOCKET;
782 }
783 case PF_PACKET:
784 return SECCLASS_PACKET_SOCKET;
785 case PF_KEY:
786 return SECCLASS_KEY_SOCKET;
3e3ff15e
CP		 787 case PF_APPLETALK:
788 return SECCLASS_APPLETALK_SOCKET;
1da177e4
LT		 789 }
790
791 return SECCLASS_SOCKET;
792}
793
794#ifdef CONFIG_PROC_FS
795static int selinux_proc_get_sid(struct proc_dir_entry *de,
796 u16 tclass,
797 u32 *sid)
798{
799 int buflen, rc;
800 char *buffer, *path, *end;
801
802 buffer = (char*)__get_free_page(GFP_KERNEL);
803 if (!buffer)
804 return -ENOMEM;
805
806 buflen = PAGE_SIZE;
807 end = buffer+buflen;
808 *--end = '\0';
809 buflen--;
810 path = end-1;
811 *path = '/';
812 while (de && de != de->parent) {
813 buflen -= de->namelen + 1;
814 if (buflen < 0)
815 break;
816 end -= de->namelen;
817 memcpy(end, de->name, de->namelen);
818 *--end = '/';
819 path = end;
820 de = de->parent;
821 }
822 rc = security_genfs_sid("proc", path, tclass, sid);
823 free_page((unsigned long)buffer);
824 return rc;
825}
826#else
827static int selinux_proc_get_sid(struct proc_dir_entry *de,
828 u16 tclass,
829 u32 *sid)
830{
831 return -EINVAL;
832}
833#endif
834
835/* The inode's security attributes must be initialized before first use. */
836static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
837{
838 struct superblock_security_struct *sbsec = NULL;
839 struct inode_security_struct *isec = inode->i_security;
840 u32 sid;
841 struct dentry *dentry;
842#define INITCONTEXTLEN 255
843 char *context = NULL;
844 unsigned len = 0;
845 int rc = 0;
1da177e4
LT		 846
847 if (isec->initialized)
848 goto out;
849
23970741 850 mutex_lock(&isec->lock);
1da177e4 851 if (isec->initialized)
23970741 852 goto out_unlock;
1da177e4
LT		 853
854 sbsec = inode->i_sb->s_security;
855 if (!sbsec->initialized) {
856 /* Defer initialization until selinux_complete_init,
857 after the initial policy is loaded and the security
858 server is ready to handle calls. */
859 spin_lock(&sbsec->isec_lock);
860 if (list_empty(&isec->list))
861 list_add(&isec->list, &sbsec->isec_head);
862 spin_unlock(&sbsec->isec_lock);
23970741 863 goto out_unlock;
1da177e4
LT		 864 }
865
866 switch (sbsec->behavior) {
867 case SECURITY_FS_USE_XATTR:
868 if (!inode->i_op->getxattr) {
869 isec->sid = sbsec->def_sid;
870 break;
871 }
872
873 /* Need a dentry, since the xattr API requires one.
874 Life would be simpler if we could just pass the inode. */
875 if (opt_dentry) {
876 /* Called from d_instantiate or d_splice_alias. */
877 dentry = dget(opt_dentry);
878 } else {
879 /* Called from selinux_complete_init, try to find a dentry. */
880 dentry = d_find_alias(inode);
881 }
882 if (!dentry) {
883 printk(KERN_WARNING "%s: no dentry for dev=%s "
884 "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
885 inode->i_ino);
23970741 886 goto out_unlock;
1da177e4
LT		 887 }
888
889 len = INITCONTEXTLEN;
890 context = kmalloc(len, GFP_KERNEL);
891 if (!context) {
892 rc = -ENOMEM;
893 dput(dentry);
23970741 894 goto out_unlock;
1da177e4
LT		 895 }
896 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
897 context, len);
898 if (rc == -ERANGE) {
899 /* Need a larger buffer. Query for the right size. */
900 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
901 NULL, 0);
902 if (rc < 0) {
903 dput(dentry);
23970741 904 goto out_unlock;
1da177e4
LT		 905 }
906 kfree(context);
907 len = rc;
908 context = kmalloc(len, GFP_KERNEL);
909 if (!context) {
910 rc = -ENOMEM;
911 dput(dentry);
23970741 912 goto out_unlock;
1da177e4
LT		 913 }
914 rc = inode->i_op->getxattr(dentry,
915 XATTR_NAME_SELINUX,
916 context, len);
917 }
918 dput(dentry);
919 if (rc < 0) {
920 if (rc != -ENODATA) {
921 printk(KERN_WARNING "%s: getxattr returned "
922 "%d for dev=%s ino=%ld\n", __FUNCTION__,
923 -rc, inode->i_sb->s_id, inode->i_ino);
924 kfree(context);
23970741 925 goto out_unlock;
1da177e4
LT		 926 }
927 /* Map ENODATA to the default file SID */
928 sid = sbsec->def_sid;
929 rc = 0;
930 } else {
f5c1d5b2
JM		 931 rc = security_context_to_sid_default(context, rc, &sid,
932 sbsec->def_sid);
1da177e4
LT		 933 if (rc) {
934 printk(KERN_WARNING "%s: context_to_sid(%s) "
935 "returned %d for dev=%s ino=%ld\n",
936 __FUNCTION__, context, -rc,
937 inode->i_sb->s_id, inode->i_ino);
938 kfree(context);
939 /* Leave with the unlabeled SID */
940 rc = 0;
941 break;
942 }
943 }
944 kfree(context);
945 isec->sid = sid;
946 break;
947 case SECURITY_FS_USE_TASK:
948 isec->sid = isec->task_sid;
949 break;
950 case SECURITY_FS_USE_TRANS:
951 /* Default to the fs SID. */
952 isec->sid = sbsec->sid;
953
954 /* Try to obtain a transition SID. */
955 isec->sclass = inode_mode_to_security_class(inode->i_mode);
956 rc = security_transition_sid(isec->task_sid,
957 sbsec->sid,
958 isec->sclass,
959 &sid);
960 if (rc)
23970741 961 goto out_unlock;
1da177e4
LT		 962 isec->sid = sid;
963 break;
c312feb2
EP		 964 case SECURITY_FS_USE_MNTPOINT:
965 isec->sid = sbsec->mntpoint_sid;
966 break;
1da177e4 967 default:
c312feb2 968 /* Default to the fs superblock SID. */
1da177e4
LT		 969 isec->sid = sbsec->sid;
970
971 if (sbsec->proc) {
972 struct proc_inode *proci = PROC_I(inode);
973 if (proci->pde) {
974 isec->sclass = inode_mode_to_security_class(inode->i_mode);
975 rc = selinux_proc_get_sid(proci->pde,
976 isec->sclass,
977 &sid);
978 if (rc)
23970741 979 goto out_unlock;
1da177e4
LT		 980 isec->sid = sid;
981 }
982 }
983 break;
984 }
985
986 isec->initialized = 1;
987
23970741
EP		 988out_unlock:
989 mutex_unlock(&isec->lock);
1da177e4
LT		 990out:
991 if (isec->sclass == SECCLASS_FILE)
992 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1da177e4
LT		 993 return rc;
994}
995
996/* Convert a Linux signal to an access vector. */
997static inline u32 signal_to_av(int sig)
998{
999 u32 perm = 0;
1000
1001 switch (sig) {
1002 case SIGCHLD:
1003 /* Commonly granted from child to parent. */
1004 perm = PROCESS__SIGCHLD;
1005 break;
1006 case SIGKILL:
1007 /* Cannot be caught or ignored */
1008 perm = PROCESS__SIGKILL;
1009 break;
1010 case SIGSTOP:
1011 /* Cannot be caught or ignored */
1012 perm = PROCESS__SIGSTOP;
1013 break;
1014 default:
1015 /* All other signals. */
1016 perm = PROCESS__SIGNAL;
1017 break;
1018 }
1019
1020 return perm;
1021}
1022
1023/* Check permission betweeen a pair of tasks, e.g. signal checks,
1024 fork check, ptrace check, etc. */
1025static int task_has_perm(struct task_struct *tsk1,
1026 struct task_struct *tsk2,
1027 u32 perms)
1028{
1029 struct task_security_struct *tsec1, *tsec2;
1030
1031 tsec1 = tsk1->security;
1032 tsec2 = tsk2->security;
1033 return avc_has_perm(tsec1->sid, tsec2->sid,
1034 SECCLASS_PROCESS, perms, NULL);
1035}
1036
1037/* Check whether a task is allowed to use a capability. */
1038static int task_has_capability(struct task_struct *tsk,
1039 int cap)
1040{
1041 struct task_security_struct *tsec;
1042 struct avc_audit_data ad;
1043
1044 tsec = tsk->security;
1045
1046 AVC_AUDIT_DATA_INIT(&ad,CAP);
1047 ad.tsk = tsk;
1048 ad.u.cap = cap;
1049
1050 return avc_has_perm(tsec->sid, tsec->sid,
1051 SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
1052}
1053
1054/* Check whether a task is allowed to use a system operation. */
1055static int task_has_system(struct task_struct *tsk,
1056 u32 perms)
1057{
1058 struct task_security_struct *tsec;
1059
1060 tsec = tsk->security;
1061
1062 return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
1063 SECCLASS_SYSTEM, perms, NULL);
1064}
1065
1066/* Check whether a task has a particular permission to an inode.
1067 The 'adp' parameter is optional and allows other audit
1068 data to be passed (e.g. the dentry). */
1069static int inode_has_perm(struct task_struct *tsk,
1070 struct inode *inode,
1071 u32 perms,
1072 struct avc_audit_data *adp)
1073{
1074 struct task_security_struct *tsec;
1075 struct inode_security_struct *isec;
1076 struct avc_audit_data ad;
1077
1078 tsec = tsk->security;
1079 isec = inode->i_security;
1080
1081 if (!adp) {
1082 adp = &ad;
1083 AVC_AUDIT_DATA_INIT(&ad, FS);
1084 ad.u.fs.inode = inode;
1085 }
1086
1087 return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
1088}
1089
1090/* Same as inode_has_perm, but pass explicit audit data containing
1091 the dentry to help the auditing code to more easily generate the
1092 pathname if needed. */
1093static inline int dentry_has_perm(struct task_struct *tsk,
1094 struct vfsmount *mnt,
1095 struct dentry *dentry,
1096 u32 av)
1097{
1098 struct inode *inode = dentry->d_inode;
1099 struct avc_audit_data ad;
1100 AVC_AUDIT_DATA_INIT(&ad,FS);
1101 ad.u.fs.mnt = mnt;
1102 ad.u.fs.dentry = dentry;
1103 return inode_has_perm(tsk, inode, av, &ad);
1104}
1105
1106/* Check whether a task can use an open file descriptor to
1107 access an inode in a given way. Check access to the
1108 descriptor itself, and then use dentry_has_perm to
1109 check a particular permission to the file.
1110 Access to the descriptor is implicitly granted if it
1111 has the same SID as the process. If av is zero, then
1112 access to the file is not checked, e.g. for cases
1113 where only the descriptor is affected like seek. */
858119e1 1114static int file_has_perm(struct task_struct *tsk,
1da177e4
LT		 1115 struct file *file,
1116 u32 av)
1117{
1118 struct task_security_struct *tsec = tsk->security;
1119 struct file_security_struct *fsec = file->f_security;
1120 struct vfsmount *mnt = file->f_vfsmnt;
1121 struct dentry *dentry = file->f_dentry;
1122 struct inode *inode = dentry->d_inode;
1123 struct avc_audit_data ad;
1124 int rc;
1125
1126 AVC_AUDIT_DATA_INIT(&ad, FS);
1127 ad.u.fs.mnt = mnt;
1128 ad.u.fs.dentry = dentry;
1129
1130 if (tsec->sid != fsec->sid) {
1131 rc = avc_has_perm(tsec->sid, fsec->sid,
1132 SECCLASS_FD,
1133 FD__USE,
1134 &ad);
1135 if (rc)
1136 return rc;
1137 }
1138
1139 /* av is zero if only checking access to the descriptor. */
1140 if (av)
1141 return inode_has_perm(tsk, inode, av, &ad);
1142
1143 return 0;
1144}
1145
1146/* Check whether a task can create a file. */
1147static int may_create(struct inode *dir,
1148 struct dentry *dentry,
1149 u16 tclass)
1150{
1151 struct task_security_struct *tsec;
1152 struct inode_security_struct *dsec;
1153 struct superblock_security_struct *sbsec;
1154 u32 newsid;
1155 struct avc_audit_data ad;
1156 int rc;
1157
1158 tsec = current->security;
1159 dsec = dir->i_security;
1160 sbsec = dir->i_sb->s_security;
1161
1162 AVC_AUDIT_DATA_INIT(&ad, FS);
1163 ad.u.fs.dentry = dentry;
1164
1165 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1166 DIR__ADD_NAME | DIR__SEARCH,
1167 &ad);
1168 if (rc)
1169 return rc;
1170
1171 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1172 newsid = tsec->create_sid;
1173 } else {
1174 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1175 &newsid);
1176 if (rc)
1177 return rc;
1178 }
1179
1180 rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1181 if (rc)
1182 return rc;
1183
1184 return avc_has_perm(newsid, sbsec->sid,
1185 SECCLASS_FILESYSTEM,
1186 FILESYSTEM__ASSOCIATE, &ad);
1187}
1188
4eb582cf
ML		 1189/* Check whether a task can create a key. */
1190static int may_create_key(u32 ksid,
1191 struct task_struct *ctx)
1192{
1193 struct task_security_struct *tsec;
1194
1195 tsec = ctx->security;
1196
1197 return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1198}
1199
1da177e4
LT		 1200#define MAY_LINK 0
1201#define MAY_UNLINK 1
1202#define MAY_RMDIR 2
1203
1204/* Check whether a task can link, unlink, or rmdir a file/directory. */
1205static int may_link(struct inode *dir,
1206 struct dentry *dentry,
1207 int kind)
1208
1209{
1210 struct task_security_struct *tsec;
1211 struct inode_security_struct *dsec, *isec;
1212 struct avc_audit_data ad;
1213 u32 av;
1214 int rc;
1215
1216 tsec = current->security;
1217 dsec = dir->i_security;
1218 isec = dentry->d_inode->i_security;
1219
1220 AVC_AUDIT_DATA_INIT(&ad, FS);
1221 ad.u.fs.dentry = dentry;
1222
1223 av = DIR__SEARCH;
1224 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1225 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1226 if (rc)
1227 return rc;
1228
1229 switch (kind) {
1230 case MAY_LINK:
1231 av = FILE__LINK;
1232 break;
1233 case MAY_UNLINK:
1234 av = FILE__UNLINK;
1235 break;
1236 case MAY_RMDIR:
1237 av = DIR__RMDIR;
1238 break;
1239 default:
1240 printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind);
1241 return 0;
1242 }
1243
1244 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1245 return rc;
1246}
1247
1248static inline int may_rename(struct inode *old_dir,
1249 struct dentry *old_dentry,
1250 struct inode *new_dir,
1251 struct dentry *new_dentry)
1252{
1253 struct task_security_struct *tsec;
1254 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1255 struct avc_audit_data ad;
1256 u32 av;
1257 int old_is_dir, new_is_dir;
1258 int rc;
1259
1260 tsec = current->security;
1261 old_dsec = old_dir->i_security;
1262 old_isec = old_dentry->d_inode->i_security;
1263 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1264 new_dsec = new_dir->i_security;
1265
1266 AVC_AUDIT_DATA_INIT(&ad, FS);
1267
1268 ad.u.fs.dentry = old_dentry;
1269 rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1270 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1271 if (rc)
1272 return rc;
1273 rc = avc_has_perm(tsec->sid, old_isec->sid,
1274 old_isec->sclass, FILE__RENAME, &ad);
1275 if (rc)
1276 return rc;
1277 if (old_is_dir && new_dir != old_dir) {
1278 rc = avc_has_perm(tsec->sid, old_isec->sid,
1279 old_isec->sclass, DIR__REPARENT, &ad);
1280 if (rc)
1281 return rc;
1282 }
1283
1284 ad.u.fs.dentry = new_dentry;
1285 av = DIR__ADD_NAME | DIR__SEARCH;
1286 if (new_dentry->d_inode)
1287 av |= DIR__REMOVE_NAME;
1288 rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1289 if (rc)
1290 return rc;
1291 if (new_dentry->d_inode) {
1292 new_isec = new_dentry->d_inode->i_security;
1293 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1294 rc = avc_has_perm(tsec->sid, new_isec->sid,
1295 new_isec->sclass,
1296 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1297 if (rc)
1298 return rc;
1299 }
1300
1301 return 0;
1302}
1303
1304/* Check whether a task can perform a filesystem operation. */
1305static int superblock_has_perm(struct task_struct *tsk,
1306 struct super_block *sb,
1307 u32 perms,
1308 struct avc_audit_data *ad)
1309{
1310 struct task_security_struct *tsec;
1311 struct superblock_security_struct *sbsec;
1312
1313 tsec = tsk->security;
1314 sbsec = sb->s_security;
1315 return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1316 perms, ad);
1317}
1318
1319/* Convert a Linux mode and permission mask to an access vector. */
1320static inline u32 file_mask_to_av(int mode, int mask)
1321{
1322 u32 av = 0;
1323
1324 if ((mode & S_IFMT) != S_IFDIR) {
1325 if (mask & MAY_EXEC)
1326 av |= FILE__EXECUTE;
1327 if (mask & MAY_READ)
1328 av |= FILE__READ;
1329
1330 if (mask & MAY_APPEND)
1331 av |= FILE__APPEND;
1332 else if (mask & MAY_WRITE)
1333 av |= FILE__WRITE;
1334
1335 } else {
1336 if (mask & MAY_EXEC)
1337 av |= DIR__SEARCH;
1338 if (mask & MAY_WRITE)
1339 av |= DIR__WRITE;
1340 if (mask & MAY_READ)
1341 av |= DIR__READ;
1342 }
1343
1344 return av;
1345}
1346
1347/* Convert a Linux file to an access vector. */
1348static inline u32 file_to_av(struct file *file)
1349{
1350 u32 av = 0;
1351
1352 if (file->f_mode & FMODE_READ)
1353 av |= FILE__READ;
1354 if (file->f_mode & FMODE_WRITE) {
1355 if (file->f_flags & O_APPEND)
1356 av |= FILE__APPEND;
1357 else
1358 av |= FILE__WRITE;
1359 }
1360
1361 return av;
1362}
1363
1da177e4
LT		 1364/* Hook functions begin here. */
1365
1366static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1367{
1368 struct task_security_struct *psec = parent->security;
1369 struct task_security_struct *csec = child->security;
1370 int rc;
1371
1372 rc = secondary_ops->ptrace(parent,child);
1373 if (rc)
1374 return rc;
1375
1376 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1377 /* Save the SID of the tracing process for later use in apply_creds. */
341c2d80 1378 if (!(child->ptrace & PT_PTRACED) && !rc)
1da177e4
LT		 1379 csec->ptrace_sid = psec->sid;
1380 return rc;
1381}
1382
1383static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1384 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1385{
1386 int error;
1387
1388 error = task_has_perm(current, target, PROCESS__GETCAP);
1389 if (error)
1390 return error;
1391
1392 return secondary_ops->capget(target, effective, inheritable, permitted);
1393}
1394
1395static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1396 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1397{
1398 int error;
1399
1400 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1401 if (error)
1402 return error;
1403
1404 return task_has_perm(current, target, PROCESS__SETCAP);
1405}
1406
1407static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1408 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1409{
1410 secondary_ops->capset_set(target, effective, inheritable, permitted);
1411}
1412
1413static int selinux_capable(struct task_struct *tsk, int cap)
1414{
1415 int rc;
1416
1417 rc = secondary_ops->capable(tsk, cap);
1418 if (rc)
1419 return rc;
1420
1421 return task_has_capability(tsk,cap);
1422}
1423
1424static int selinux_sysctl(ctl_table *table, int op)
1425{
1426 int error = 0;
1427 u32 av;
1428 struct task_security_struct *tsec;
1429 u32 tsid;
1430 int rc;
1431
1432 rc = secondary_ops->sysctl(table, op);
1433 if (rc)
1434 return rc;
1435
1436 tsec = current->security;
1437
1438 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1439 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1440 if (rc) {
1441 /* Default to the well-defined sysctl SID. */
1442 tsid = SECINITSID_SYSCTL;
1443 }
1444
1445 /* The op values are "defined" in sysctl.c, thereby creating
1446 * a bad coupling between this module and sysctl.c */
1447 if(op == 001) {
1448 error = avc_has_perm(tsec->sid, tsid,
1449 SECCLASS_DIR, DIR__SEARCH, NULL);
1450 } else {
1451 av = 0;
1452 if (op & 004)
1453 av |= FILE__READ;
1454 if (op & 002)
1455 av |= FILE__WRITE;
1456 if (av)
1457 error = avc_has_perm(tsec->sid, tsid,
1458 SECCLASS_FILE, av, NULL);
1459 }
1460
1461 return error;
1462}
1463
1464static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1465{
1466 int rc = 0;
1467
1468 if (!sb)
1469 return 0;
1470
1471 switch (cmds) {
1472 case Q_SYNC:
1473 case Q_QUOTAON:
1474 case Q_QUOTAOFF:
1475 case Q_SETINFO:
1476 case Q_SETQUOTA:
1477 rc = superblock_has_perm(current,
1478 sb,
1479 FILESYSTEM__QUOTAMOD, NULL);
1480 break;
1481 case Q_GETFMT:
1482 case Q_GETINFO:
1483 case Q_GETQUOTA:
1484 rc = superblock_has_perm(current,
1485 sb,
1486 FILESYSTEM__QUOTAGET, NULL);
1487 break;
1488 default:
1489 rc = 0; /* let the kernel handle invalid cmds */
1490 break;
1491 }
1492 return rc;
1493}
1494
1495static int selinux_quota_on(struct dentry *dentry)
1496{
1497 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1498}
1499
1500static int selinux_syslog(int type)
1501{
1502 int rc;
1503
1504 rc = secondary_ops->syslog(type);
1505 if (rc)
1506 return rc;
1507
1508 switch (type) {
1509 case 3: /* Read last kernel messages */
1510 case 10: /* Return size of the log buffer */
1511 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1512 break;
1513 case 6: /* Disable logging to console */
1514 case 7: /* Enable logging to console */
1515 case 8: /* Set level of messages printed to console */
1516 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1517 break;
1518 case 0: /* Close log */
1519 case 1: /* Open log */
1520 case 2: /* Read from log */
1521 case 4: /* Read/clear last kernel messages */
1522 case 5: /* Clear ring buffer */
1523 default:
1524 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1525 break;
1526 }
1527 return rc;
1528}
1529
1530/*
1531 * Check that a process has enough memory to allocate a new virtual
1532 * mapping. 0 means there is enough memory for the allocation to
1533 * succeed and -ENOMEM implies there is not.
1534 *
1535 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1536 * if the capability is granted, but __vm_enough_memory requires 1 if
1537 * the capability is granted.
1538 *
1539 * Do not audit the selinux permission check, as this is applied to all
1540 * processes that allocate mappings.
1541 */
1542static int selinux_vm_enough_memory(long pages)
1543{
1544 int rc, cap_sys_admin = 0;
1545 struct task_security_struct *tsec = current->security;
1546
1547 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1548 if (rc == 0)
1549 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1550 SECCLASS_CAPABILITY,
1551 CAP_TO_MASK(CAP_SYS_ADMIN),
1552 NULL);
1553
1554 if (rc == 0)
1555 cap_sys_admin = 1;
1556
1557 return __vm_enough_memory(pages, cap_sys_admin);
1558}
1559
1560/* binprm security operations */
1561
1562static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1563{
1564 struct bprm_security_struct *bsec;
1565
89d155ef 1566 bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1da177e4
LT		 1567 if (!bsec)
1568 return -ENOMEM;
1569
1da177e4
LT		 1570 bsec->bprm = bprm;
1571 bsec->sid = SECINITSID_UNLABELED;
1572 bsec->set = 0;
1573
1574 bprm->security = bsec;
1575 return 0;
1576}
1577
1578static int selinux_bprm_set_security(struct linux_binprm *bprm)
1579{
1580 struct task_security_struct *tsec;
1581 struct inode *inode = bprm->file->f_dentry->d_inode;
1582 struct inode_security_struct *isec;
1583 struct bprm_security_struct *bsec;
1584 u32 newsid;
1585 struct avc_audit_data ad;
1586 int rc;
1587
1588 rc = secondary_ops->bprm_set_security(bprm);
1589 if (rc)
1590 return rc;
1591
1592 bsec = bprm->security;
1593
1594 if (bsec->set)
1595 return 0;
1596
1597 tsec = current->security;
1598 isec = inode->i_security;
1599
1600 /* Default to the current task SID. */
1601 bsec->sid = tsec->sid;
1602
28eba5bf 1603 /* Reset fs, key, and sock SIDs on execve. */
1da177e4 1604 tsec->create_sid = 0;
28eba5bf 1605 tsec->keycreate_sid = 0;
42c3e03e 1606 tsec->sockcreate_sid = 0;
1da177e4
LT		 1607
1608 if (tsec->exec_sid) {
1609 newsid = tsec->exec_sid;
1610 /* Reset exec SID on execve. */
1611 tsec->exec_sid = 0;
1612 } else {
1613 /* Check for a default transition on this program. */
1614 rc = security_transition_sid(tsec->sid, isec->sid,
1615 SECCLASS_PROCESS, &newsid);
1616 if (rc)
1617 return rc;
1618 }
1619
1620 AVC_AUDIT_DATA_INIT(&ad, FS);
1621 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1622 ad.u.fs.dentry = bprm->file->f_dentry;
1623
1624 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1625 newsid = tsec->sid;
1626
1627 if (tsec->sid == newsid) {
1628 rc = avc_has_perm(tsec->sid, isec->sid,
1629 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1630 if (rc)
1631 return rc;
1632 } else {
1633 /* Check permissions for the transition. */
1634 rc = avc_has_perm(tsec->sid, newsid,
1635 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1636 if (rc)
1637 return rc;
1638
1639 rc = avc_has_perm(newsid, isec->sid,
1640 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1641 if (rc)
1642 return rc;
1643
1644 /* Clear any possibly unsafe personality bits on exec: */
1645 current->personality &= ~PER_CLEAR_ON_SETID;
1646
1647 /* Set the security field to the new SID. */
1648 bsec->sid = newsid;
1649 }
1650
1651 bsec->set = 1;
1652 return 0;
1653}
1654
1655static int selinux_bprm_check_security (struct linux_binprm *bprm)
1656{
1657 return secondary_ops->bprm_check_security(bprm);
1658}
1659
1660
1661static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1662{
1663 struct task_security_struct *tsec = current->security;
1664 int atsecure = 0;
1665
1666 if (tsec->osid != tsec->sid) {
1667 /* Enable secure mode for SIDs transitions unless
1668 the noatsecure permission is granted between
1669 the two SIDs, i.e. ahp returns 0. */
1670 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1671 SECCLASS_PROCESS,
1672 PROCESS__NOATSECURE, NULL);
1673 }
1674
1675 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1676}
1677
1678static void selinux_bprm_free_security(struct linux_binprm *bprm)
1679{
9a5f04bf 1680 kfree(bprm->security);
1da177e4 1681 bprm->security = NULL;
1da177e4
LT		 1682}
1683
1684extern struct vfsmount *selinuxfs_mount;
1685extern struct dentry *selinux_null;
1686
1687/* Derived from fs/exec.c:flush_old_files. */
1688static inline void flush_unauthorized_files(struct files_struct * files)
1689{
1690 struct avc_audit_data ad;
1691 struct file *file, *devnull = NULL;
1692 struct tty_struct *tty = current->signal->tty;
badf1662 1693 struct fdtable *fdt;
1da177e4
LT		 1694 long j = -1;
1695
1696 if (tty) {
1697 file_list_lock();
2f512016 1698 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1da177e4
LT		 1699 if (file) {
1700 /* Revalidate access to controlling tty.
1701 Use inode_has_perm on the tty inode directly rather
1702 than using file_has_perm, as this particular open
1703 file may belong to another process and we are only
1704 interested in the inode-based check here. */
1705 struct inode *inode = file->f_dentry->d_inode;
1706 if (inode_has_perm(current, inode,
1707 FILE__READ | FILE__WRITE, NULL)) {
1708 /* Reset controlling tty. */
1709 current->signal->tty = NULL;
1710 current->signal->tty_old_pgrp = 0;
1711 }
1712 }
1713 file_list_unlock();
1714 }
1715
1716 /* Revalidate access to inherited open files. */
1717
1718 AVC_AUDIT_DATA_INIT(&ad,FS);
1719
1720 spin_lock(&files->file_lock);
1721 for (;;) {
1722 unsigned long set, i;
1723 int fd;
1724
1725 j++;
1726 i = j * __NFDBITS;
badf1662
DS		 1727 fdt = files_fdtable(files);
1728 if (i >= fdt->max_fds || i >= fdt->max_fdset)
1da177e4 1729 break;
badf1662 1730 set = fdt->open_fds->fds_bits[j];
1da177e4
LT		 1731 if (!set)
1732 continue;
1733 spin_unlock(&files->file_lock);
1734 for ( ; set ; i++,set >>= 1) {
1735 if (set & 1) {
1736 file = fget(i);
1737 if (!file)
1738 continue;
1739 if (file_has_perm(current,
1740 file,
1741 file_to_av(file))) {
1742 sys_close(i);
1743 fd = get_unused_fd();
1744 if (fd != i) {
1745 if (fd >= 0)
1746 put_unused_fd(fd);
1747 fput(file);
1748 continue;
1749 }
1750 if (devnull) {
095975da 1751 get_file(devnull);
1da177e4
LT		 1752 } else {
1753 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1754 if (!devnull) {
1755 put_unused_fd(fd);
1756 fput(file);
1757 continue;
1758 }
1759 }
1760 fd_install(fd, devnull);
1761 }
1762 fput(file);
1763 }
1764 }
1765 spin_lock(&files->file_lock);
1766
1767 }
1768 spin_unlock(&files->file_lock);
1769}
1770
1771static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1772{
1773 struct task_security_struct *tsec;
1774 struct bprm_security_struct *bsec;
1775 u32 sid;
1776 int rc;
1777
1778 secondary_ops->bprm_apply_creds(bprm, unsafe);
1779
1780 tsec = current->security;
1781
1782 bsec = bprm->security;
1783 sid = bsec->sid;
1784
1785 tsec->osid = tsec->sid;
1786 bsec->unsafe = 0;
1787 if (tsec->sid != sid) {
1788 /* Check for shared state. If not ok, leave SID
1789 unchanged and kill. */
1790 if (unsafe & LSM_UNSAFE_SHARE) {
1791 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1792 PROCESS__SHARE, NULL);
1793 if (rc) {
1794 bsec->unsafe = 1;
1795 return;
1796 }
1797 }
1798
1799 /* Check for ptracing, and update the task SID if ok.
1800 Otherwise, leave SID unchanged and kill. */
1801 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1802 rc = avc_has_perm(tsec->ptrace_sid, sid,
1803 SECCLASS_PROCESS, PROCESS__PTRACE,
1804 NULL);
1805 if (rc) {
1806 bsec->unsafe = 1;
1807 return;
1808 }
1809 }
1810 tsec->sid = sid;
1811 }
1812}
1813
1814/*
1815 * called after apply_creds without the task lock held
1816 */
1817static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1818{
1819 struct task_security_struct *tsec;
1820 struct rlimit *rlim, *initrlim;
1821 struct itimerval itimer;
1822 struct bprm_security_struct *bsec;
1823 int rc, i;
1824
1825 tsec = current->security;
1826 bsec = bprm->security;
1827
1828 if (bsec->unsafe) {
1829 force_sig_specific(SIGKILL, current);
1830 return;
1831 }
1832 if (tsec->osid == tsec->sid)
1833 return;
1834
1835 /* Close files for which the new task SID is not authorized. */
1836 flush_unauthorized_files(current->files);
1837
1838 /* Check whether the new SID can inherit signal state
1839 from the old SID. If not, clear itimers to avoid
1840 subsequent signal generation and flush and unblock
1841 signals. This must occur _after_ the task SID has
1842 been updated so that any kill done after the flush
1843 will be checked against the new SID. */
1844 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1845 PROCESS__SIGINH, NULL);
1846 if (rc) {
1847 memset(&itimer, 0, sizeof itimer);
1848 for (i = 0; i < 3; i++)
1849 do_setitimer(i, &itimer, NULL);
1850 flush_signals(current);
1851 spin_lock_irq(&current->sighand->siglock);
1852 flush_signal_handlers(current, 1);
1853 sigemptyset(&current->blocked);
1854 recalc_sigpending();
1855 spin_unlock_irq(&current->sighand->siglock);
1856 }
1857
1858 /* Check whether the new SID can inherit resource limits
1859 from the old SID. If not, reset all soft limits to
1860 the lower of the current task's hard limit and the init
1861 task's soft limit. Note that the setting of hard limits
1862 (even to lower them) can be controlled by the setrlimit
1863 check. The inclusion of the init task's soft limit into
1864 the computation is to avoid resetting soft limits higher
1865 than the default soft limit for cases where the default
1866 is lower than the hard limit, e.g. RLIMIT_CORE or
1867 RLIMIT_STACK.*/
1868 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1869 PROCESS__RLIMITINH, NULL);
1870 if (rc) {
1871 for (i = 0; i < RLIM_NLIMITS; i++) {
1872 rlim = current->signal->rlim + i;
1873 initrlim = init_task.signal->rlim+i;
1874 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1875 }
1876 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1877 /*
1878 * This will cause RLIMIT_CPU calculations
1879 * to be refigured.
1880 */
1881 current->it_prof_expires = jiffies_to_cputime(1);
1882 }
1883 }
1884
1885 /* Wake up the parent if it is waiting so that it can
1886 recheck wait permission to the new task SID. */
1887 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1888}
1889
1890/* superblock security operations */
1891
1892static int selinux_sb_alloc_security(struct super_block *sb)
1893{
1894 return superblock_alloc_security(sb);
1895}
1896
1897static void selinux_sb_free_security(struct super_block *sb)
1898{
1899 superblock_free_security(sb);
1900}
1901
1902static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1903{
1904 if (plen > olen)
1905 return 0;
1906
1907 return !memcmp(prefix, option, plen);
1908}
1909
1910static inline int selinux_option(char *option, int len)
1911{
1912 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1913 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
0808925e
EP		 1914 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len) ||
1915 match_prefix("rootcontext=", sizeof("rootcontext=")-1, option, len));
1da177e4
LT		 1916}
1917
1918static inline void take_option(char **to, char *from, int *first, int len)
1919{
1920 if (!*first) {
1921 **to = ',';
1922 *to += 1;
1923 }
1924 else
1925 *first = 0;
1926 memcpy(*to, from, len);
1927 *to += len;
1928}
1929
1930static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1931{
1932 int fnosec, fsec, rc = 0;
1933 char *in_save, *in_curr, *in_end;
1934 char *sec_curr, *nosec_save, *nosec;
1935
1936 in_curr = orig;
1937 sec_curr = copy;
1938
1939 /* Binary mount data: just copy */
1940 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1941 copy_page(sec_curr, in_curr);
1942 goto out;
1943 }
1944
1945 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1946 if (!nosec) {
1947 rc = -ENOMEM;
1948 goto out;
1949 }
1950
1951 nosec_save = nosec;
1952 fnosec = fsec = 1;
1953 in_save = in_end = orig;
1954
1955 do {
1956 if (*in_end == ',' || *in_end == '\0') {
1957 int len = in_end - in_curr;
1958
1959 if (selinux_option(in_curr, len))
1960 take_option(&sec_curr, in_curr, &fsec, len);
1961 else
1962 take_option(&nosec, in_curr, &fnosec, len);
1963
1964 in_curr = in_end + 1;
1965 }
1966 } while (*in_end++);
1967
6931dfc9 1968 strcpy(in_save, nosec_save);
da3caa20 1969 free_page((unsigned long)nosec_save);
1da177e4
LT		 1970out:
1971 return rc;
1972}
1973
1974static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1975{
1976 struct avc_audit_data ad;
1977 int rc;
1978
1979 rc = superblock_doinit(sb, data);
1980 if (rc)
1981 return rc;
1982
1983 AVC_AUDIT_DATA_INIT(&ad,FS);
1984 ad.u.fs.dentry = sb->s_root;
1985 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1986}
1987
726c3342 1988static int selinux_sb_statfs(struct dentry *dentry)
1da177e4
LT		 1989{
1990 struct avc_audit_data ad;
1991
1992 AVC_AUDIT_DATA_INIT(&ad,FS);
726c3342
DH		 1993 ad.u.fs.dentry = dentry->d_sb->s_root;
1994 return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT		 1995}
1996
1997static int selinux_mount(char * dev_name,
1998 struct nameidata *nd,
1999 char * type,
2000 unsigned long flags,
2001 void * data)
2002{
2003 int rc;
2004
2005 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
2006 if (rc)
2007 return rc;
2008
2009 if (flags & MS_REMOUNT)
2010 return superblock_has_perm(current, nd->mnt->mnt_sb,
2011 FILESYSTEM__REMOUNT, NULL);
2012 else
2013 return dentry_has_perm(current, nd->mnt, nd->dentry,
2014 FILE__MOUNTON);
2015}
2016
2017static int selinux_umount(struct vfsmount *mnt, int flags)
2018{
2019 int rc;
2020
2021 rc = secondary_ops->sb_umount(mnt, flags);
2022 if (rc)
2023 return rc;
2024
2025 return superblock_has_perm(current,mnt->mnt_sb,
2026 FILESYSTEM__UNMOUNT,NULL);
2027}
2028
2029/* inode security operations */
2030
2031static int selinux_inode_alloc_security(struct inode *inode)
2032{
2033 return inode_alloc_security(inode);
2034}
2035
2036static void selinux_inode_free_security(struct inode *inode)
2037{
2038 inode_free_security(inode);
2039}
2040
5e41ff9e
SS		 2041static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2042 char **name, void **value,
2043 size_t *len)
2044{
2045 struct task_security_struct *tsec;
2046 struct inode_security_struct *dsec;
2047 struct superblock_security_struct *sbsec;
570bc1c2 2048 u32 newsid, clen;
5e41ff9e 2049 int rc;
570bc1c2 2050 char *namep = NULL, *context;
5e41ff9e
SS		 2051
2052 tsec = current->security;
2053 dsec = dir->i_security;
2054 sbsec = dir->i_sb->s_security;
5e41ff9e
SS		 2055
2056 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
2057 newsid = tsec->create_sid;
2058 } else {
2059 rc = security_transition_sid(tsec->sid, dsec->sid,
2060 inode_mode_to_security_class(inode->i_mode),
2061 &newsid);
2062 if (rc) {
2063 printk(KERN_WARNING "%s: "
2064 "security_transition_sid failed, rc=%d (dev=%s "
2065 "ino=%ld)\n",
2066 __FUNCTION__,
2067 -rc, inode->i_sb->s_id, inode->i_ino);
2068 return rc;
2069 }
2070 }
2071
296fddf7
EP		 2072 /* Possibly defer initialization to selinux_complete_init. */
2073 if (sbsec->initialized) {
2074 struct inode_security_struct *isec = inode->i_security;
2075 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2076 isec->sid = newsid;
2077 isec->initialized = 1;
2078 }
5e41ff9e 2079
8aad3875 2080 if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
25a74f3b
SS		 2081 return -EOPNOTSUPP;
2082
570bc1c2
SS		 2083 if (name) {
2084 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
2085 if (!namep)
2086 return -ENOMEM;
2087 *name = namep;
2088 }
5e41ff9e 2089
570bc1c2
SS		 2090 if (value && len) {
2091 rc = security_sid_to_context(newsid, &context, &clen);
2092 if (rc) {
2093 kfree(namep);
2094 return rc;
2095 }
2096 *value = context;
2097 *len = clen;
5e41ff9e 2098 }
5e41ff9e 2099
5e41ff9e
SS		 2100 return 0;
2101}
2102
1da177e4
LT		 2103static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2104{
2105 return may_create(dir, dentry, SECCLASS_FILE);
2106}
2107
1da177e4
LT		 2108static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2109{
2110 int rc;
2111
2112 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2113 if (rc)
2114 return rc;
2115 return may_link(dir, old_dentry, MAY_LINK);
2116}
2117
1da177e4
LT		 2118static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2119{
2120 int rc;
2121
2122 rc = secondary_ops->inode_unlink(dir, dentry);
2123 if (rc)
2124 return rc;
2125 return may_link(dir, dentry, MAY_UNLINK);
2126}
2127
2128static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2129{
2130 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2131}
2132
1da177e4
LT		 2133static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2134{
2135 return may_create(dir, dentry, SECCLASS_DIR);
2136}
2137
1da177e4
LT		 2138static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2139{
2140 return may_link(dir, dentry, MAY_RMDIR);
2141}
2142
2143static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2144{
2145 int rc;
2146
2147 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2148 if (rc)
2149 return rc;
2150
2151 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2152}
2153
1da177e4
LT		 2154static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2155 struct inode *new_inode, struct dentry *new_dentry)
2156{
2157 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2158}
2159
1da177e4
LT		 2160static int selinux_inode_readlink(struct dentry *dentry)
2161{
2162 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2163}
2164
2165static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2166{
2167 int rc;
2168
2169 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2170 if (rc)
2171 return rc;
2172 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2173}
2174
2175static int selinux_inode_permission(struct inode *inode, int mask,
2176 struct nameidata *nd)
2177{
2178 int rc;
2179
2180 rc = secondary_ops->inode_permission(inode, mask, nd);
2181 if (rc)
2182 return rc;
2183
2184 if (!mask) {
2185 /* No permission to check. Existence test. */
2186 return 0;
2187 }
2188
2189 return inode_has_perm(current, inode,
2190 file_mask_to_av(inode->i_mode, mask), NULL);
2191}
2192
2193static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2194{
2195 int rc;
2196
2197 rc = secondary_ops->inode_setattr(dentry, iattr);
2198 if (rc)
2199 return rc;
2200
2201 if (iattr->ia_valid & ATTR_FORCE)
2202 return 0;
2203
2204 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2205 ATTR_ATIME_SET | ATTR_MTIME_SET))
2206 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2207
2208 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2209}
2210
2211static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2212{
2213 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2214}
2215
2216static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2217{
2218 struct task_security_struct *tsec = current->security;
2219 struct inode *inode = dentry->d_inode;
2220 struct inode_security_struct *isec = inode->i_security;
2221 struct superblock_security_struct *sbsec;
2222 struct avc_audit_data ad;
2223 u32 newsid;
2224 int rc = 0;
2225
2226 if (strcmp(name, XATTR_NAME_SELINUX)) {
2227 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2228 sizeof XATTR_SECURITY_PREFIX - 1) &&
2229 !capable(CAP_SYS_ADMIN)) {
2230 /* A different attribute in the security namespace.
2231 Restrict to administrator. */
2232 return -EPERM;
2233 }
2234
2235 /* Not an attribute we recognize, so just check the
2236 ordinary setattr permission. */
2237 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2238 }
2239
2240 sbsec = inode->i_sb->s_security;
2241 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2242 return -EOPNOTSUPP;
2243
2244 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2245 return -EPERM;
2246
2247 AVC_AUDIT_DATA_INIT(&ad,FS);
2248 ad.u.fs.dentry = dentry;
2249
2250 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2251 FILE__RELABELFROM, &ad);
2252 if (rc)
2253 return rc;
2254
2255 rc = security_context_to_sid(value, size, &newsid);
2256 if (rc)
2257 return rc;
2258
2259 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2260 FILE__RELABELTO, &ad);
2261 if (rc)
2262 return rc;
2263
2264 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2265 isec->sclass);
2266 if (rc)
2267 return rc;
2268
2269 return avc_has_perm(newsid,
2270 sbsec->sid,
2271 SECCLASS_FILESYSTEM,
2272 FILESYSTEM__ASSOCIATE,
2273 &ad);
2274}
2275
2276static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2277 void *value, size_t size, int flags)
2278{
2279 struct inode *inode = dentry->d_inode;
2280 struct inode_security_struct *isec = inode->i_security;
2281 u32 newsid;
2282 int rc;
2283
2284 if (strcmp(name, XATTR_NAME_SELINUX)) {
2285 /* Not an attribute we recognize, so nothing to do. */
2286 return;
2287 }
2288
2289 rc = security_context_to_sid(value, size, &newsid);
2290 if (rc) {
2291 printk(KERN_WARNING "%s: unable to obtain SID for context "
2292 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2293 return;
2294 }
2295
2296 isec->sid = newsid;
2297 return;
2298}
2299
2300static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2301{
1da177e4
LT		 2302 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2303}
2304
2305static int selinux_inode_listxattr (struct dentry *dentry)
2306{
2307 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2308}
2309
2310static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2311{
2312 if (strcmp(name, XATTR_NAME_SELINUX)) {
2313 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2314 sizeof XATTR_SECURITY_PREFIX - 1) &&
2315 !capable(CAP_SYS_ADMIN)) {
2316 /* A different attribute in the security namespace.
2317 Restrict to administrator. */
2318 return -EPERM;
2319 }
2320
2321 /* Not an attribute we recognize, so just check the
2322 ordinary setattr permission. Might want a separate
2323 permission for removexattr. */
2324 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2325 }
2326
2327 /* No one is allowed to remove a SELinux security label.
2328 You can change the label, but all data must be labeled. */
2329 return -EACCES;
2330}
2331
8c8570fb
DK		 2332static const char *selinux_inode_xattr_getsuffix(void)
2333{
2334 return XATTR_SELINUX_SUFFIX;
2335}
2336
d381d8a9
JM		 2337/*
2338 * Copy the in-core inode security context value to the user. If the
2339 * getxattr() prior to this succeeded, check to see if we need to
2340 * canonicalize the value to be finally returned to the user.
2341 *
2342 * Permission check is handled by selinux_inode_getxattr hook.
2343 */
7306a0b9 2344static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
1da177e4
LT		 2345{
2346 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2347
8c8570fb
DK		 2348 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2349 return -EOPNOTSUPP;
d381d8a9 2350
8c8570fb 2351 return selinux_getsecurity(isec->sid, buffer, size);
1da177e4
LT		 2352}
2353
2354static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2355 const void *value, size_t size, int flags)
2356{
2357 struct inode_security_struct *isec = inode->i_security;
2358 u32 newsid;
2359 int rc;
2360
2361 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2362 return -EOPNOTSUPP;
2363
2364 if (!value || !size)
2365 return -EACCES;
2366
2367 rc = security_context_to_sid((void*)value, size, &newsid);
2368 if (rc)
2369 return rc;
2370
2371 isec->sid = newsid;
2372 return 0;
2373}
2374
2375static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2376{
2377 const int len = sizeof(XATTR_NAME_SELINUX);
2378 if (buffer && len <= buffer_size)
2379 memcpy(buffer, XATTR_NAME_SELINUX, len);
2380 return len;
2381}
2382
2383/* file security operations */
2384
2385static int selinux_file_permission(struct file *file, int mask)
2386{
7420ed23 2387 int rc;
1da177e4
LT		 2388 struct inode *inode = file->f_dentry->d_inode;
2389
2390 if (!mask) {
2391 /* No permission to check. Existence test. */
2392 return 0;
2393 }
2394
2395 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2396 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2397 mask |= MAY_APPEND;
2398
7420ed23
VY		 2399 rc = file_has_perm(current, file,
2400 file_mask_to_av(inode->i_mode, mask));
2401 if (rc)
2402 return rc;
2403
2404 return selinux_netlbl_inode_permission(inode, mask);
1da177e4
LT		 2405}
2406
2407static int selinux_file_alloc_security(struct file *file)
2408{
2409 return file_alloc_security(file);
2410}
2411
2412static void selinux_file_free_security(struct file *file)
2413{
2414 file_free_security(file);
2415}
2416
2417static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2418 unsigned long arg)
2419{
2420 int error = 0;
2421
2422 switch (cmd) {
2423 case FIONREAD:
2424 /* fall through */
2425 case FIBMAP:
2426 /* fall through */
2427 case FIGETBSZ:
2428 /* fall through */
2429 case EXT2_IOC_GETFLAGS:
2430 /* fall through */
2431 case EXT2_IOC_GETVERSION:
2432 error = file_has_perm(current, file, FILE__GETATTR);
2433 break;
2434
2435 case EXT2_IOC_SETFLAGS:
2436 /* fall through */
2437 case EXT2_IOC_SETVERSION:
2438 error = file_has_perm(current, file, FILE__SETATTR);
2439 break;
2440
2441 /* sys_ioctl() checks */
2442 case FIONBIO:
2443 /* fall through */
2444 case FIOASYNC:
2445 error = file_has_perm(current, file, 0);
2446 break;
2447
2448 case KDSKBENT:
2449 case KDSKBSENT:
2450 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2451 break;
2452
2453 /* default case assumes that the command will go
2454 * to the file's ioctl() function.
2455 */
2456 default:
2457 error = file_has_perm(current, file, FILE__IOCTL);
2458
2459 }
2460 return error;
2461}
2462
2463static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2464{
2465#ifndef CONFIG_PPC32
2466 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2467 /*
2468 * We are making executable an anonymous mapping or a
2469 * private file mapping that will also be writable.
2470 * This has an additional check.
2471 */
2472 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2473 if (rc)
2474 return rc;
2475 }
2476#endif
2477
2478 if (file) {
2479 /* read access is always possible with a mapping */
2480 u32 av = FILE__READ;
2481
2482 /* write access only matters if the mapping is shared */
2483 if (shared && (prot & PROT_WRITE))
2484 av |= FILE__WRITE;
2485
2486 if (prot & PROT_EXEC)
2487 av |= FILE__EXECUTE;
2488
2489 return file_has_perm(current, file, av);
2490 }
2491 return 0;
2492}
2493
2494static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2495 unsigned long prot, unsigned long flags)
2496{
2497 int rc;
2498
2499 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2500 if (rc)
2501 return rc;
2502
2503 if (selinux_checkreqprot)
2504 prot = reqprot;
2505
2506 return file_map_prot_check(file, prot,
2507 (flags & MAP_TYPE) == MAP_SHARED);
2508}
2509
2510static int selinux_file_mprotect(struct vm_area_struct *vma,
2511 unsigned long reqprot,
2512 unsigned long prot)
2513{
2514 int rc;
2515
2516 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2517 if (rc)
2518 return rc;
2519
2520 if (selinux_checkreqprot)
2521 prot = reqprot;
2522
2523#ifndef CONFIG_PPC32
db4c9641
SS		 2524 if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
2525 rc = 0;
2526 if (vma->vm_start >= vma->vm_mm->start_brk &&
2527 vma->vm_end <= vma->vm_mm->brk) {
2528 rc = task_has_perm(current, current,
2529 PROCESS__EXECHEAP);
2530 } else if (!vma->vm_file &&
2531 vma->vm_start <= vma->vm_mm->start_stack &&
2532 vma->vm_end >= vma->vm_mm->start_stack) {
2533 rc = task_has_perm(current, current, PROCESS__EXECSTACK);
2534 } else if (vma->vm_file && vma->anon_vma) {
2535 /*
2536 * We are making executable a file mapping that has
2537 * had some COW done. Since pages might have been
2538 * written, check ability to execute the possibly
2539 * modified content. This typically should only
2540 * occur for text relocations.
2541 */
2542 rc = file_has_perm(current, vma->vm_file,
2543 FILE__EXECMOD);
2544 }