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[PATCH] SELinux: eliminate inode_security_set_security
[linux-2.6-block.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>
54#include <asm/semaphore.h>
55#include <asm/ioctls.h>
56#include <linux/bitops.h>
57#include <linux/interrupt.h>
58#include <linux/netdevice.h> /* for network interface checks */
59#include <linux/netlink.h>
60#include <linux/tcp.h>
61#include <linux/udp.h>
62#include <linux/quota.h>
63#include <linux/un.h> /* for Unix socket types */
64#include <net/af_unix.h> /* for Unix socket types */
65#include <linux/parser.h>
66#include <linux/nfs_mount.h>
67#include <net/ipv6.h>
68#include <linux/hugetlb.h>
69#include <linux/personality.h>
70#include <linux/sysctl.h>
71#include <linux/audit.h>
6931dfc9 72#include <linux/string.h>
877ce7c1 73#include <linux/selinux.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));
1da177e4
LT		 188 init_MUTEX(&isec->sem);
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
1da177e4
LT		 245 init_MUTEX(&sbsec->sem);
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
597 down(&sbsec->sem);
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:
692 up(&sbsec->sem);
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;
846 int hold_sem = 0;
847
848 if (isec->initialized)
849 goto out;
850
851 down(&isec->sem);
852 hold_sem = 1;
853 if (isec->initialized)
854 goto out;
855
856 sbsec = inode->i_sb->s_security;
857 if (!sbsec->initialized) {
858 /* Defer initialization until selinux_complete_init,
859 after the initial policy is loaded and the security
860 server is ready to handle calls. */
861 spin_lock(&sbsec->isec_lock);
862 if (list_empty(&isec->list))
863 list_add(&isec->list, &sbsec->isec_head);
864 spin_unlock(&sbsec->isec_lock);
865 goto out;
866 }
867
868 switch (sbsec->behavior) {
869 case SECURITY_FS_USE_XATTR:
870 if (!inode->i_op->getxattr) {
871 isec->sid = sbsec->def_sid;
872 break;
873 }
874
875 /* Need a dentry, since the xattr API requires one.
876 Life would be simpler if we could just pass the inode. */
877 if (opt_dentry) {
878 /* Called from d_instantiate or d_splice_alias. */
879 dentry = dget(opt_dentry);
880 } else {
881 /* Called from selinux_complete_init, try to find a dentry. */
882 dentry = d_find_alias(inode);
883 }
884 if (!dentry) {
885 printk(KERN_WARNING "%s: no dentry for dev=%s "
886 "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
887 inode->i_ino);
888 goto out;
889 }
890
891 len = INITCONTEXTLEN;
892 context = kmalloc(len, GFP_KERNEL);
893 if (!context) {
894 rc = -ENOMEM;
895 dput(dentry);
896 goto out;
897 }
898 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
899 context, len);
900 if (rc == -ERANGE) {
901 /* Need a larger buffer. Query for the right size. */
902 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
903 NULL, 0);
904 if (rc < 0) {
905 dput(dentry);
906 goto out;
907 }
908 kfree(context);
909 len = rc;
910 context = kmalloc(len, GFP_KERNEL);
911 if (!context) {
912 rc = -ENOMEM;
913 dput(dentry);
914 goto out;
915 }
916 rc = inode->i_op->getxattr(dentry,
917 XATTR_NAME_SELINUX,
918 context, len);
919 }
920 dput(dentry);
921 if (rc < 0) {
922 if (rc != -ENODATA) {
923 printk(KERN_WARNING "%s: getxattr returned "
924 "%d for dev=%s ino=%ld\n", __FUNCTION__,
925 -rc, inode->i_sb->s_id, inode->i_ino);
926 kfree(context);
927 goto out;
928 }
929 /* Map ENODATA to the default file SID */
930 sid = sbsec->def_sid;
931 rc = 0;
932 } else {
f5c1d5b2
JM		 933 rc = security_context_to_sid_default(context, rc, &sid,
934 sbsec->def_sid);
1da177e4
LT		 935 if (rc) {
936 printk(KERN_WARNING "%s: context_to_sid(%s) "
937 "returned %d for dev=%s ino=%ld\n",
938 __FUNCTION__, context, -rc,
939 inode->i_sb->s_id, inode->i_ino);
940 kfree(context);
941 /* Leave with the unlabeled SID */
942 rc = 0;
943 break;
944 }
945 }
946 kfree(context);
947 isec->sid = sid;
948 break;
949 case SECURITY_FS_USE_TASK:
950 isec->sid = isec->task_sid;
951 break;
952 case SECURITY_FS_USE_TRANS:
953 /* Default to the fs SID. */
954 isec->sid = sbsec->sid;
955
956 /* Try to obtain a transition SID. */
957 isec->sclass = inode_mode_to_security_class(inode->i_mode);
958 rc = security_transition_sid(isec->task_sid,
959 sbsec->sid,
960 isec->sclass,
961 &sid);
962 if (rc)
963 goto out;
964 isec->sid = sid;
965 break;
c312feb2
EP		 966 case SECURITY_FS_USE_MNTPOINT:
967 isec->sid = sbsec->mntpoint_sid;
968 break;
1da177e4 969 default:
c312feb2 970 /* Default to the fs superblock SID. */
1da177e4
LT		 971 isec->sid = sbsec->sid;
972
973 if (sbsec->proc) {
974 struct proc_inode *proci = PROC_I(inode);
975 if (proci->pde) {
976 isec->sclass = inode_mode_to_security_class(inode->i_mode);
977 rc = selinux_proc_get_sid(proci->pde,
978 isec->sclass,
979 &sid);
980 if (rc)
981 goto out;
982 isec->sid = sid;
983 }
984 }
985 break;
986 }
987
988 isec->initialized = 1;
989
990out:
991 if (isec->sclass == SECCLASS_FILE)
992 isec->sclass = inode_mode_to_security_class(inode->i_mode);
993
994 if (hold_sem)
995 up(&isec->sem);
996 return rc;
997}
998
999/* Convert a Linux signal to an access vector. */
1000static inline u32 signal_to_av(int sig)
1001{
1002 u32 perm = 0;
1003
1004 switch (sig) {
1005 case SIGCHLD:
1006 /* Commonly granted from child to parent. */
1007 perm = PROCESS__SIGCHLD;
1008 break;
1009 case SIGKILL:
1010 /* Cannot be caught or ignored */
1011 perm = PROCESS__SIGKILL;
1012 break;
1013 case SIGSTOP:
1014 /* Cannot be caught or ignored */
1015 perm = PROCESS__SIGSTOP;
1016 break;
1017 default:
1018 /* All other signals. */
1019 perm = PROCESS__SIGNAL;
1020 break;
1021 }
1022
1023 return perm;
1024}
1025
1026/* Check permission betweeen a pair of tasks, e.g. signal checks,
1027 fork check, ptrace check, etc. */
1028static int task_has_perm(struct task_struct *tsk1,
1029 struct task_struct *tsk2,
1030 u32 perms)
1031{
1032 struct task_security_struct *tsec1, *tsec2;
1033
1034 tsec1 = tsk1->security;
1035 tsec2 = tsk2->security;
1036 return avc_has_perm(tsec1->sid, tsec2->sid,
1037 SECCLASS_PROCESS, perms, NULL);
1038}
1039
1040/* Check whether a task is allowed to use a capability. */
1041static int task_has_capability(struct task_struct *tsk,
1042 int cap)
1043{
1044 struct task_security_struct *tsec;
1045 struct avc_audit_data ad;
1046
1047 tsec = tsk->security;
1048
1049 AVC_AUDIT_DATA_INIT(&ad,CAP);
1050 ad.tsk = tsk;
1051 ad.u.cap = cap;
1052
1053 return avc_has_perm(tsec->sid, tsec->sid,
1054 SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
1055}
1056
1057/* Check whether a task is allowed to use a system operation. */
1058static int task_has_system(struct task_struct *tsk,
1059 u32 perms)
1060{
1061 struct task_security_struct *tsec;
1062
1063 tsec = tsk->security;
1064
1065 return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
1066 SECCLASS_SYSTEM, perms, NULL);
1067}
1068
1069/* Check whether a task has a particular permission to an inode.
1070 The 'adp' parameter is optional and allows other audit
1071 data to be passed (e.g. the dentry). */
1072static int inode_has_perm(struct task_struct *tsk,
1073 struct inode *inode,
1074 u32 perms,
1075 struct avc_audit_data *adp)
1076{
1077 struct task_security_struct *tsec;
1078 struct inode_security_struct *isec;
1079 struct avc_audit_data ad;
1080
1081 tsec = tsk->security;
1082 isec = inode->i_security;
1083
1084 if (!adp) {
1085 adp = &ad;
1086 AVC_AUDIT_DATA_INIT(&ad, FS);
1087 ad.u.fs.inode = inode;
1088 }
1089
1090 return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
1091}
1092
1093/* Same as inode_has_perm, but pass explicit audit data containing
1094 the dentry to help the auditing code to more easily generate the
1095 pathname if needed. */
1096static inline int dentry_has_perm(struct task_struct *tsk,
1097 struct vfsmount *mnt,
1098 struct dentry *dentry,
1099 u32 av)
1100{
1101 struct inode *inode = dentry->d_inode;
1102 struct avc_audit_data ad;
1103 AVC_AUDIT_DATA_INIT(&ad,FS);
1104 ad.u.fs.mnt = mnt;
1105 ad.u.fs.dentry = dentry;
1106 return inode_has_perm(tsk, inode, av, &ad);
1107}
1108
1109/* Check whether a task can use an open file descriptor to
1110 access an inode in a given way. Check access to the
1111 descriptor itself, and then use dentry_has_perm to
1112 check a particular permission to the file.
1113 Access to the descriptor is implicitly granted if it
1114 has the same SID as the process. If av is zero, then
1115 access to the file is not checked, e.g. for cases
1116 where only the descriptor is affected like seek. */
858119e1 1117static int file_has_perm(struct task_struct *tsk,
1da177e4
LT		 1118 struct file *file,
1119 u32 av)
1120{
1121 struct task_security_struct *tsec = tsk->security;
1122 struct file_security_struct *fsec = file->f_security;
1123 struct vfsmount *mnt = file->f_vfsmnt;
1124 struct dentry *dentry = file->f_dentry;
1125 struct inode *inode = dentry->d_inode;
1126 struct avc_audit_data ad;
1127 int rc;
1128
1129 AVC_AUDIT_DATA_INIT(&ad, FS);
1130 ad.u.fs.mnt = mnt;
1131 ad.u.fs.dentry = dentry;
1132
1133 if (tsec->sid != fsec->sid) {
1134 rc = avc_has_perm(tsec->sid, fsec->sid,
1135 SECCLASS_FD,
1136 FD__USE,
1137 &ad);
1138 if (rc)
1139 return rc;
1140 }
1141
1142 /* av is zero if only checking access to the descriptor. */
1143 if (av)
1144 return inode_has_perm(tsk, inode, av, &ad);
1145
1146 return 0;
1147}
1148
1149/* Check whether a task can create a file. */
1150static int may_create(struct inode *dir,
1151 struct dentry *dentry,
1152 u16 tclass)
1153{
1154 struct task_security_struct *tsec;
1155 struct inode_security_struct *dsec;
1156 struct superblock_security_struct *sbsec;
1157 u32 newsid;
1158 struct avc_audit_data ad;
1159 int rc;
1160
1161 tsec = current->security;
1162 dsec = dir->i_security;
1163 sbsec = dir->i_sb->s_security;
1164
1165 AVC_AUDIT_DATA_INIT(&ad, FS);
1166 ad.u.fs.dentry = dentry;
1167
1168 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1169 DIR__ADD_NAME | DIR__SEARCH,
1170 &ad);
1171 if (rc)
1172 return rc;
1173
1174 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1175 newsid = tsec->create_sid;
1176 } else {
1177 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1178 &newsid);
1179 if (rc)
1180 return rc;
1181 }
1182
1183 rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1184 if (rc)
1185 return rc;
1186
1187 return avc_has_perm(newsid, sbsec->sid,
1188 SECCLASS_FILESYSTEM,
1189 FILESYSTEM__ASSOCIATE, &ad);
1190}
1191
4eb582cf
ML		 1192/* Check whether a task can create a key. */
1193static int may_create_key(u32 ksid,
1194 struct task_struct *ctx)
1195{
1196 struct task_security_struct *tsec;
1197
1198 tsec = ctx->security;
1199
1200 return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1201}
1202
1da177e4
LT		 1203#define MAY_LINK 0
1204#define MAY_UNLINK 1
1205#define MAY_RMDIR 2
1206
1207/* Check whether a task can link, unlink, or rmdir a file/directory. */
1208static int may_link(struct inode *dir,
1209 struct dentry *dentry,
1210 int kind)
1211
1212{
1213 struct task_security_struct *tsec;
1214 struct inode_security_struct *dsec, *isec;
1215 struct avc_audit_data ad;
1216 u32 av;
1217 int rc;
1218
1219 tsec = current->security;
1220 dsec = dir->i_security;
1221 isec = dentry->d_inode->i_security;
1222
1223 AVC_AUDIT_DATA_INIT(&ad, FS);
1224 ad.u.fs.dentry = dentry;
1225
1226 av = DIR__SEARCH;
1227 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1228 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1229 if (rc)
1230 return rc;
1231
1232 switch (kind) {
1233 case MAY_LINK:
1234 av = FILE__LINK;
1235 break;
1236 case MAY_UNLINK:
1237 av = FILE__UNLINK;
1238 break;
1239 case MAY_RMDIR:
1240 av = DIR__RMDIR;
1241 break;
1242 default:
1243 printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind);
1244 return 0;
1245 }
1246
1247 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1248 return rc;
1249}
1250
1251static inline int may_rename(struct inode *old_dir,
1252 struct dentry *old_dentry,
1253 struct inode *new_dir,
1254 struct dentry *new_dentry)
1255{
1256 struct task_security_struct *tsec;
1257 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1258 struct avc_audit_data ad;
1259 u32 av;
1260 int old_is_dir, new_is_dir;
1261 int rc;
1262
1263 tsec = current->security;
1264 old_dsec = old_dir->i_security;
1265 old_isec = old_dentry->d_inode->i_security;
1266 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1267 new_dsec = new_dir->i_security;
1268
1269 AVC_AUDIT_DATA_INIT(&ad, FS);
1270
1271 ad.u.fs.dentry = old_dentry;
1272 rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1273 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1274 if (rc)
1275 return rc;
1276 rc = avc_has_perm(tsec->sid, old_isec->sid,
1277 old_isec->sclass, FILE__RENAME, &ad);
1278 if (rc)
1279 return rc;
1280 if (old_is_dir && new_dir != old_dir) {
1281 rc = avc_has_perm(tsec->sid, old_isec->sid,
1282 old_isec->sclass, DIR__REPARENT, &ad);
1283 if (rc)
1284 return rc;
1285 }
1286
1287 ad.u.fs.dentry = new_dentry;
1288 av = DIR__ADD_NAME | DIR__SEARCH;
1289 if (new_dentry->d_inode)
1290 av |= DIR__REMOVE_NAME;
1291 rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1292 if (rc)
1293 return rc;
1294 if (new_dentry->d_inode) {
1295 new_isec = new_dentry->d_inode->i_security;
1296 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1297 rc = avc_has_perm(tsec->sid, new_isec->sid,
1298 new_isec->sclass,
1299 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1300 if (rc)
1301 return rc;
1302 }
1303
1304 return 0;
1305}
1306
1307/* Check whether a task can perform a filesystem operation. */
1308static int superblock_has_perm(struct task_struct *tsk,
1309 struct super_block *sb,
1310 u32 perms,
1311 struct avc_audit_data *ad)
1312{
1313 struct task_security_struct *tsec;
1314 struct superblock_security_struct *sbsec;
1315
1316 tsec = tsk->security;
1317 sbsec = sb->s_security;
1318 return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1319 perms, ad);
1320}
1321
1322/* Convert a Linux mode and permission mask to an access vector. */
1323static inline u32 file_mask_to_av(int mode, int mask)
1324{
1325 u32 av = 0;
1326
1327 if ((mode & S_IFMT) != S_IFDIR) {
1328 if (mask & MAY_EXEC)
1329 av |= FILE__EXECUTE;
1330 if (mask & MAY_READ)
1331 av |= FILE__READ;
1332
1333 if (mask & MAY_APPEND)
1334 av |= FILE__APPEND;
1335 else if (mask & MAY_WRITE)
1336 av |= FILE__WRITE;
1337
1338 } else {
1339 if (mask & MAY_EXEC)
1340 av |= DIR__SEARCH;
1341 if (mask & MAY_WRITE)
1342 av |= DIR__WRITE;
1343 if (mask & MAY_READ)
1344 av |= DIR__READ;
1345 }
1346
1347 return av;
1348}
1349
1350/* Convert a Linux file to an access vector. */
1351static inline u32 file_to_av(struct file *file)
1352{
1353 u32 av = 0;
1354
1355 if (file->f_mode & FMODE_READ)
1356 av |= FILE__READ;
1357 if (file->f_mode & FMODE_WRITE) {
1358 if (file->f_flags & O_APPEND)
1359 av |= FILE__APPEND;
1360 else
1361 av |= FILE__WRITE;
1362 }
1363
1364 return av;
1365}
1366
1da177e4
LT		 1367/* Hook functions begin here. */
1368
1369static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1370{
1371 struct task_security_struct *psec = parent->security;
1372 struct task_security_struct *csec = child->security;
1373 int rc;
1374
1375 rc = secondary_ops->ptrace(parent,child);
1376 if (rc)
1377 return rc;
1378
1379 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1380 /* Save the SID of the tracing process for later use in apply_creds. */
341c2d80 1381 if (!(child->ptrace & PT_PTRACED) && !rc)
1da177e4
LT		 1382 csec->ptrace_sid = psec->sid;
1383 return rc;
1384}
1385
1386static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1387 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1388{
1389 int error;
1390
1391 error = task_has_perm(current, target, PROCESS__GETCAP);
1392 if (error)
1393 return error;
1394
1395 return secondary_ops->capget(target, effective, inheritable, permitted);
1396}
1397
1398static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1399 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1400{
1401 int error;
1402
1403 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1404 if (error)
1405 return error;
1406
1407 return task_has_perm(current, target, PROCESS__SETCAP);
1408}
1409
1410static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1411 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1412{
1413 secondary_ops->capset_set(target, effective, inheritable, permitted);
1414}
1415
1416static int selinux_capable(struct task_struct *tsk, int cap)
1417{
1418 int rc;
1419
1420 rc = secondary_ops->capable(tsk, cap);
1421 if (rc)
1422 return rc;
1423
1424 return task_has_capability(tsk,cap);
1425}
1426
1427static int selinux_sysctl(ctl_table *table, int op)
1428{
1429 int error = 0;
1430 u32 av;
1431 struct task_security_struct *tsec;
1432 u32 tsid;
1433 int rc;
1434
1435 rc = secondary_ops->sysctl(table, op);
1436 if (rc)
1437 return rc;
1438
1439 tsec = current->security;
1440
1441 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1442 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1443 if (rc) {
1444 /* Default to the well-defined sysctl SID. */
1445 tsid = SECINITSID_SYSCTL;
1446 }
1447
1448 /* The op values are "defined" in sysctl.c, thereby creating
1449 * a bad coupling between this module and sysctl.c */
1450 if(op == 001) {
1451 error = avc_has_perm(tsec->sid, tsid,
1452 SECCLASS_DIR, DIR__SEARCH, NULL);
1453 } else {
1454 av = 0;
1455 if (op & 004)
1456 av |= FILE__READ;
1457 if (op & 002)
1458 av |= FILE__WRITE;
1459 if (av)
1460 error = avc_has_perm(tsec->sid, tsid,
1461 SECCLASS_FILE, av, NULL);
1462 }
1463
1464 return error;
1465}
1466
1467static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1468{
1469 int rc = 0;
1470
1471 if (!sb)
1472 return 0;
1473
1474 switch (cmds) {
1475 case Q_SYNC:
1476 case Q_QUOTAON:
1477 case Q_QUOTAOFF:
1478 case Q_SETINFO:
1479 case Q_SETQUOTA:
1480 rc = superblock_has_perm(current,
1481 sb,
1482 FILESYSTEM__QUOTAMOD, NULL);
1483 break;
1484 case Q_GETFMT:
1485 case Q_GETINFO:
1486 case Q_GETQUOTA:
1487 rc = superblock_has_perm(current,
1488 sb,
1489 FILESYSTEM__QUOTAGET, NULL);
1490 break;
1491 default:
1492 rc = 0; /* let the kernel handle invalid cmds */
1493 break;
1494 }
1495 return rc;
1496}
1497
1498static int selinux_quota_on(struct dentry *dentry)
1499{
1500 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1501}
1502
1503static int selinux_syslog(int type)
1504{
1505 int rc;
1506
1507 rc = secondary_ops->syslog(type);
1508 if (rc)
1509 return rc;
1510
1511 switch (type) {
1512 case 3: /* Read last kernel messages */
1513 case 10: /* Return size of the log buffer */
1514 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1515 break;
1516 case 6: /* Disable logging to console */
1517 case 7: /* Enable logging to console */
1518 case 8: /* Set level of messages printed to console */
1519 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1520 break;
1521 case 0: /* Close log */
1522 case 1: /* Open log */
1523 case 2: /* Read from log */
1524 case 4: /* Read/clear last kernel messages */
1525 case 5: /* Clear ring buffer */
1526 default:
1527 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1528 break;
1529 }
1530 return rc;
1531}
1532
1533/*
1534 * Check that a process has enough memory to allocate a new virtual
1535 * mapping. 0 means there is enough memory for the allocation to
1536 * succeed and -ENOMEM implies there is not.
1537 *
1538 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1539 * if the capability is granted, but __vm_enough_memory requires 1 if
1540 * the capability is granted.
1541 *
1542 * Do not audit the selinux permission check, as this is applied to all
1543 * processes that allocate mappings.
1544 */
1545static int selinux_vm_enough_memory(long pages)
1546{
1547 int rc, cap_sys_admin = 0;
1548 struct task_security_struct *tsec = current->security;
1549
1550 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1551 if (rc == 0)
1552 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1553 SECCLASS_CAPABILITY,
1554 CAP_TO_MASK(CAP_SYS_ADMIN),
1555 NULL);
1556
1557 if (rc == 0)
1558 cap_sys_admin = 1;
1559
1560 return __vm_enough_memory(pages, cap_sys_admin);
1561}
1562
1563/* binprm security operations */
1564
1565static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1566{
1567 struct bprm_security_struct *bsec;
1568
89d155ef 1569 bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1da177e4
LT		 1570 if (!bsec)
1571 return -ENOMEM;
1572
1da177e4
LT		 1573 bsec->bprm = bprm;
1574 bsec->sid = SECINITSID_UNLABELED;
1575 bsec->set = 0;
1576
1577 bprm->security = bsec;
1578 return 0;
1579}
1580
1581static int selinux_bprm_set_security(struct linux_binprm *bprm)
1582{
1583 struct task_security_struct *tsec;
1584 struct inode *inode = bprm->file->f_dentry->d_inode;
1585 struct inode_security_struct *isec;
1586 struct bprm_security_struct *bsec;
1587 u32 newsid;
1588 struct avc_audit_data ad;
1589 int rc;
1590
1591 rc = secondary_ops->bprm_set_security(bprm);
1592 if (rc)
1593 return rc;
1594
1595 bsec = bprm->security;
1596
1597 if (bsec->set)
1598 return 0;
1599
1600 tsec = current->security;
1601 isec = inode->i_security;
1602
1603 /* Default to the current task SID. */
1604 bsec->sid = tsec->sid;
1605
28eba5bf 1606 /* Reset fs, key, and sock SIDs on execve. */
1da177e4 1607 tsec->create_sid = 0;
28eba5bf 1608 tsec->keycreate_sid = 0;
42c3e03e 1609 tsec->sockcreate_sid = 0;
1da177e4
LT		 1610
1611 if (tsec->exec_sid) {
1612 newsid = tsec->exec_sid;
1613 /* Reset exec SID on execve. */
1614 tsec->exec_sid = 0;
1615 } else {
1616 /* Check for a default transition on this program. */
1617 rc = security_transition_sid(tsec->sid, isec->sid,
1618 SECCLASS_PROCESS, &newsid);
1619 if (rc)
1620 return rc;
1621 }
1622
1623 AVC_AUDIT_DATA_INIT(&ad, FS);
1624 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1625 ad.u.fs.dentry = bprm->file->f_dentry;
1626
1627 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1628 newsid = tsec->sid;
1629
1630 if (tsec->sid == newsid) {
1631 rc = avc_has_perm(tsec->sid, isec->sid,
1632 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1633 if (rc)
1634 return rc;
1635 } else {
1636 /* Check permissions for the transition. */
1637 rc = avc_has_perm(tsec->sid, newsid,
1638 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1639 if (rc)
1640 return rc;
1641
1642 rc = avc_has_perm(newsid, isec->sid,
1643 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1644 if (rc)
1645 return rc;
1646
1647 /* Clear any possibly unsafe personality bits on exec: */
1648 current->personality &= ~PER_CLEAR_ON_SETID;
1649
1650 /* Set the security field to the new SID. */
1651 bsec->sid = newsid;
1652 }
1653
1654 bsec->set = 1;
1655 return 0;
1656}
1657
1658static int selinux_bprm_check_security (struct linux_binprm *bprm)
1659{
1660 return secondary_ops->bprm_check_security(bprm);
1661}
1662
1663
1664static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1665{
1666 struct task_security_struct *tsec = current->security;
1667 int atsecure = 0;
1668
1669 if (tsec->osid != tsec->sid) {
1670 /* Enable secure mode for SIDs transitions unless
1671 the noatsecure permission is granted between
1672 the two SIDs, i.e. ahp returns 0. */
1673 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1674 SECCLASS_PROCESS,
1675 PROCESS__NOATSECURE, NULL);
1676 }
1677
1678 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1679}
1680
1681static void selinux_bprm_free_security(struct linux_binprm *bprm)
1682{
9a5f04bf 1683 kfree(bprm->security);
1da177e4 1684 bprm->security = NULL;
1da177e4
LT		 1685}
1686
1687extern struct vfsmount *selinuxfs_mount;
1688extern struct dentry *selinux_null;
1689
1690/* Derived from fs/exec.c:flush_old_files. */
1691static inline void flush_unauthorized_files(struct files_struct * files)
1692{
1693 struct avc_audit_data ad;
1694 struct file *file, *devnull = NULL;
1695 struct tty_struct *tty = current->signal->tty;
badf1662 1696 struct fdtable *fdt;
1da177e4
LT		 1697 long j = -1;
1698
1699 if (tty) {
1700 file_list_lock();
2f512016 1701 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1da177e4
LT		 1702 if (file) {
1703 /* Revalidate access to controlling tty.
1704 Use inode_has_perm on the tty inode directly rather
1705 than using file_has_perm, as this particular open
1706 file may belong to another process and we are only
1707 interested in the inode-based check here. */
1708 struct inode *inode = file->f_dentry->d_inode;
1709 if (inode_has_perm(current, inode,
1710 FILE__READ | FILE__WRITE, NULL)) {
1711 /* Reset controlling tty. */
1712 current->signal->tty = NULL;
1713 current->signal->tty_old_pgrp = 0;
1714 }
1715 }
1716 file_list_unlock();
1717 }
1718
1719 /* Revalidate access to inherited open files. */
1720
1721 AVC_AUDIT_DATA_INIT(&ad,FS);
1722
1723 spin_lock(&files->file_lock);
1724 for (;;) {
1725 unsigned long set, i;
1726 int fd;
1727
1728 j++;
1729 i = j * __NFDBITS;
badf1662
DS		 1730 fdt = files_fdtable(files);
1731 if (i >= fdt->max_fds || i >= fdt->max_fdset)
1da177e4 1732 break;
badf1662 1733 set = fdt->open_fds->fds_bits[j];
1da177e4
LT		 1734 if (!set)
1735 continue;
1736 spin_unlock(&files->file_lock);
1737 for ( ; set ; i++,set >>= 1) {
1738 if (set & 1) {
1739 file = fget(i);
1740 if (!file)
1741 continue;
1742 if (file_has_perm(current,
1743 file,
1744 file_to_av(file))) {
1745 sys_close(i);
1746 fd = get_unused_fd();
1747 if (fd != i) {
1748 if (fd >= 0)
1749 put_unused_fd(fd);
1750 fput(file);
1751 continue;
1752 }
1753 if (devnull) {
095975da 1754 get_file(devnull);
1da177e4
LT		 1755 } else {
1756 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1757 if (!devnull) {
1758 put_unused_fd(fd);
1759 fput(file);
1760 continue;
1761 }
1762 }
1763 fd_install(fd, devnull);
1764 }
1765 fput(file);
1766 }
1767 }
1768 spin_lock(&files->file_lock);
1769
1770 }
1771 spin_unlock(&files->file_lock);
1772}
1773
1774static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1775{
1776 struct task_security_struct *tsec;
1777 struct bprm_security_struct *bsec;
1778 u32 sid;
1779 int rc;
1780
1781 secondary_ops->bprm_apply_creds(bprm, unsafe);
1782
1783 tsec = current->security;
1784
1785 bsec = bprm->security;
1786 sid = bsec->sid;
1787
1788 tsec->osid = tsec->sid;
1789 bsec->unsafe = 0;
1790 if (tsec->sid != sid) {
1791 /* Check for shared state. If not ok, leave SID
1792 unchanged and kill. */
1793 if (unsafe & LSM_UNSAFE_SHARE) {
1794 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1795 PROCESS__SHARE, NULL);
1796 if (rc) {
1797 bsec->unsafe = 1;
1798 return;
1799 }
1800 }
1801
1802 /* Check for ptracing, and update the task SID if ok.
1803 Otherwise, leave SID unchanged and kill. */
1804 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1805 rc = avc_has_perm(tsec->ptrace_sid, sid,
1806 SECCLASS_PROCESS, PROCESS__PTRACE,
1807 NULL);
1808 if (rc) {
1809 bsec->unsafe = 1;
1810 return;
1811 }
1812 }
1813 tsec->sid = sid;
1814 }
1815}
1816
1817/*
1818 * called after apply_creds without the task lock held
1819 */
1820static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1821{
1822 struct task_security_struct *tsec;
1823 struct rlimit *rlim, *initrlim;
1824 struct itimerval itimer;
1825 struct bprm_security_struct *bsec;
1826 int rc, i;
1827
1828 tsec = current->security;
1829 bsec = bprm->security;
1830
1831 if (bsec->unsafe) {
1832 force_sig_specific(SIGKILL, current);
1833 return;
1834 }
1835 if (tsec->osid == tsec->sid)
1836 return;
1837
1838 /* Close files for which the new task SID is not authorized. */
1839 flush_unauthorized_files(current->files);
1840
1841 /* Check whether the new SID can inherit signal state
1842 from the old SID. If not, clear itimers to avoid
1843 subsequent signal generation and flush and unblock
1844 signals. This must occur _after_ the task SID has
1845 been updated so that any kill done after the flush
1846 will be checked against the new SID. */
1847 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1848 PROCESS__SIGINH, NULL);
1849 if (rc) {
1850 memset(&itimer, 0, sizeof itimer);
1851 for (i = 0; i < 3; i++)
1852 do_setitimer(i, &itimer, NULL);
1853 flush_signals(current);
1854 spin_lock_irq(&current->sighand->siglock);
1855 flush_signal_handlers(current, 1);
1856 sigemptyset(&current->blocked);
1857 recalc_sigpending();
1858 spin_unlock_irq(&current->sighand->siglock);
1859 }
1860
1861 /* Check whether the new SID can inherit resource limits
1862 from the old SID. If not, reset all soft limits to
1863 the lower of the current task's hard limit and the init
1864 task's soft limit. Note that the setting of hard limits
1865 (even to lower them) can be controlled by the setrlimit
1866 check. The inclusion of the init task's soft limit into
1867 the computation is to avoid resetting soft limits higher
1868 than the default soft limit for cases where the default
1869 is lower than the hard limit, e.g. RLIMIT_CORE or
1870 RLIMIT_STACK.*/
1871 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1872 PROCESS__RLIMITINH, NULL);
1873 if (rc) {
1874 for (i = 0; i < RLIM_NLIMITS; i++) {
1875 rlim = current->signal->rlim + i;
1876 initrlim = init_task.signal->rlim+i;
1877 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1878 }
1879 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1880 /*
1881 * This will cause RLIMIT_CPU calculations
1882 * to be refigured.
1883 */
1884 current->it_prof_expires = jiffies_to_cputime(1);
1885 }
1886 }
1887
1888 /* Wake up the parent if it is waiting so that it can
1889 recheck wait permission to the new task SID. */
1890 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1891}
1892
1893/* superblock security operations */
1894
1895static int selinux_sb_alloc_security(struct super_block *sb)
1896{
1897 return superblock_alloc_security(sb);
1898}
1899
1900static void selinux_sb_free_security(struct super_block *sb)
1901{
1902 superblock_free_security(sb);
1903}
1904
1905static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1906{
1907 if (plen > olen)
1908 return 0;
1909
1910 return !memcmp(prefix, option, plen);
1911}
1912
1913static inline int selinux_option(char *option, int len)
1914{
1915 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1916 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
0808925e
EP		 1917 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len) ||
1918 match_prefix("rootcontext=", sizeof("rootcontext=")-1, option, len));
1da177e4
LT		 1919}
1920
1921static inline void take_option(char **to, char *from, int *first, int len)
1922{
1923 if (!*first) {
1924 **to = ',';
1925 *to += 1;
1926 }
1927 else
1928 *first = 0;
1929 memcpy(*to, from, len);
1930 *to += len;
1931}
1932
1933static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1934{
1935 int fnosec, fsec, rc = 0;
1936 char *in_save, *in_curr, *in_end;
1937 char *sec_curr, *nosec_save, *nosec;
1938
1939 in_curr = orig;
1940 sec_curr = copy;
1941
1942 /* Binary mount data: just copy */
1943 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1944 copy_page(sec_curr, in_curr);
1945 goto out;
1946 }
1947
1948 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1949 if (!nosec) {
1950 rc = -ENOMEM;
1951 goto out;
1952 }
1953
1954 nosec_save = nosec;
1955 fnosec = fsec = 1;
1956 in_save = in_end = orig;
1957
1958 do {
1959 if (*in_end == ',' || *in_end == '\0') {
1960 int len = in_end - in_curr;
1961
1962 if (selinux_option(in_curr, len))
1963 take_option(&sec_curr, in_curr, &fsec, len);
1964 else
1965 take_option(&nosec, in_curr, &fnosec, len);
1966
1967 in_curr = in_end + 1;
1968 }
1969 } while (*in_end++);
1970
6931dfc9 1971 strcpy(in_save, nosec_save);
da3caa20 1972 free_page((unsigned long)nosec_save);
1da177e4
LT		 1973out:
1974 return rc;
1975}
1976
1977static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1978{
1979 struct avc_audit_data ad;
1980 int rc;
1981
1982 rc = superblock_doinit(sb, data);
1983 if (rc)
1984 return rc;
1985
1986 AVC_AUDIT_DATA_INIT(&ad,FS);
1987 ad.u.fs.dentry = sb->s_root;
1988 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1989}
1990
726c3342 1991static int selinux_sb_statfs(struct dentry *dentry)
1da177e4
LT		 1992{
1993 struct avc_audit_data ad;
1994
1995 AVC_AUDIT_DATA_INIT(&ad,FS);
726c3342
DH		 1996 ad.u.fs.dentry = dentry->d_sb->s_root;
1997 return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT		 1998}
1999
2000static int selinux_mount(char * dev_name,
2001 struct nameidata *nd,
2002 char * type,
2003 unsigned long flags,
2004 void * data)
2005{
2006 int rc;
2007
2008 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
2009 if (rc)
2010 return rc;
2011
2012 if (flags & MS_REMOUNT)
2013 return superblock_has_perm(current, nd->mnt->mnt_sb,
2014 FILESYSTEM__REMOUNT, NULL);
2015 else
2016 return dentry_has_perm(current, nd->mnt, nd->dentry,
2017 FILE__MOUNTON);
2018}
2019
2020static int selinux_umount(struct vfsmount *mnt, int flags)
2021{
2022 int rc;
2023
2024 rc = secondary_ops->sb_umount(mnt, flags);
2025 if (rc)
2026 return rc;
2027
2028 return superblock_has_perm(current,mnt->mnt_sb,
2029 FILESYSTEM__UNMOUNT,NULL);
2030}
2031
2032/* inode security operations */
2033
2034static int selinux_inode_alloc_security(struct inode *inode)
2035{
2036 return inode_alloc_security(inode);
2037}
2038
2039static void selinux_inode_free_security(struct inode *inode)
2040{
2041 inode_free_security(inode);
2042}
2043
5e41ff9e
SS		 2044static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2045 char **name, void **value,
2046 size_t *len)
2047{
2048 struct task_security_struct *tsec;
2049 struct inode_security_struct *dsec;
2050 struct superblock_security_struct *sbsec;
570bc1c2 2051 u32 newsid, clen;
5e41ff9e 2052 int rc;
570bc1c2 2053 char *namep = NULL, *context;
5e41ff9e
SS		 2054
2055 tsec = current->security;
2056 dsec = dir->i_security;
2057 sbsec = dir->i_sb->s_security;
5e41ff9e
SS		 2058
2059 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
2060 newsid = tsec->create_sid;
2061 } else {
2062 rc = security_transition_sid(tsec->sid, dsec->sid,
2063 inode_mode_to_security_class(inode->i_mode),
2064 &newsid);
2065 if (rc) {
2066 printk(KERN_WARNING "%s: "
2067 "security_transition_sid failed, rc=%d (dev=%s "
2068 "ino=%ld)\n",
2069 __FUNCTION__,
2070 -rc, inode->i_sb->s_id, inode->i_ino);
2071 return rc;
2072 }
2073 }
2074
296fddf7
EP		 2075 /* Possibly defer initialization to selinux_complete_init. */
2076 if (sbsec->initialized) {
2077 struct inode_security_struct *isec = inode->i_security;
2078 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2079 isec->sid = newsid;
2080 isec->initialized = 1;
2081 }
5e41ff9e 2082
8aad3875 2083 if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
25a74f3b
SS		 2084 return -EOPNOTSUPP;
2085
570bc1c2
SS		 2086 if (name) {
2087 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
2088 if (!namep)
2089 return -ENOMEM;
2090 *name = namep;
2091 }
5e41ff9e 2092
570bc1c2
SS		 2093 if (value && len) {
2094 rc = security_sid_to_context(newsid, &context, &clen);
2095 if (rc) {
2096 kfree(namep);
2097 return rc;
2098 }
2099 *value = context;
2100 *len = clen;
5e41ff9e 2101 }
5e41ff9e 2102
5e41ff9e
SS		 2103 return 0;
2104}
2105
1da177e4
LT		 2106static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2107{
2108 return may_create(dir, dentry, SECCLASS_FILE);
2109}
2110
1da177e4
LT		 2111static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2112{
2113 int rc;
2114
2115 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2116 if (rc)
2117 return rc;
2118 return may_link(dir, old_dentry, MAY_LINK);
2119}
2120
1da177e4
LT		 2121static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2122{
2123 int rc;
2124
2125 rc = secondary_ops->inode_unlink(dir, dentry);
2126 if (rc)
2127 return rc;
2128 return may_link(dir, dentry, MAY_UNLINK);
2129}
2130
2131static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2132{
2133 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2134}
2135
1da177e4
LT		 2136static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2137{
2138 return may_create(dir, dentry, SECCLASS_DIR);
2139}
2140
1da177e4
LT		 2141static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2142{
2143 return may_link(dir, dentry, MAY_RMDIR);
2144}
2145
2146static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2147{
2148 int rc;
2149
2150 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2151 if (rc)
2152 return rc;
2153
2154 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2155}
2156
1da177e4
LT		 2157static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2158 struct inode *new_inode, struct dentry *new_dentry)
2159{
2160 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2161}
2162
1da177e4
LT		 2163static int selinux_inode_readlink(struct dentry *dentry)
2164{
2165 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2166}
2167
2168static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2169{
2170 int rc;
2171
2172 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2173 if (rc)
2174 return rc;
2175 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2176}
2177
2178static int selinux_inode_permission(struct inode *inode, int mask,
2179 struct nameidata *nd)
2180{
2181 int rc;
2182
2183 rc = secondary_ops->inode_permission(inode, mask, nd);
2184 if (rc)
2185 return rc;
2186
2187 if (!mask) {
2188 /* No permission to check. Existence test. */
2189 return 0;
2190 }
2191
2192 return inode_has_perm(current, inode,
2193 file_mask_to_av(inode->i_mode, mask), NULL);
2194}
2195
2196static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2197{
2198 int rc;
2199
2200 rc = secondary_ops->inode_setattr(dentry, iattr);
2201 if (rc)
2202 return rc;
2203
2204 if (iattr->ia_valid & ATTR_FORCE)
2205 return 0;
2206
2207 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2208 ATTR_ATIME_SET | ATTR_MTIME_SET))
2209 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2210
2211 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2212}
2213
2214static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2215{
2216 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2217}
2218
2219static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2220{
2221 struct task_security_struct *tsec = current->security;
2222 struct inode *inode = dentry->d_inode;
2223 struct inode_security_struct *isec = inode->i_security;
2224 struct superblock_security_struct *sbsec;
2225 struct avc_audit_data ad;
2226 u32 newsid;
2227 int rc = 0;
2228
2229 if (strcmp(name, XATTR_NAME_SELINUX)) {
2230 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2231 sizeof XATTR_SECURITY_PREFIX - 1) &&
2232 !capable(CAP_SYS_ADMIN)) {
2233 /* A different attribute in the security namespace.
2234 Restrict to administrator. */
2235 return -EPERM;
2236 }
2237
2238 /* Not an attribute we recognize, so just check the
2239 ordinary setattr permission. */
2240 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2241 }
2242
2243 sbsec = inode->i_sb->s_security;
2244 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2245 return -EOPNOTSUPP;
2246
2247 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2248 return -EPERM;
2249
2250 AVC_AUDIT_DATA_INIT(&ad,FS);
2251 ad.u.fs.dentry = dentry;
2252
2253 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2254 FILE__RELABELFROM, &ad);
2255 if (rc)
2256 return rc;
2257
2258 rc = security_context_to_sid(value, size, &newsid);
2259 if (rc)
2260 return rc;
2261
2262 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2263 FILE__RELABELTO, &ad);
2264 if (rc)
2265 return rc;
2266
2267 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2268 isec->sclass);
2269 if (rc)
2270 return rc;
2271
2272 return avc_has_perm(newsid,
2273 sbsec->sid,
2274 SECCLASS_FILESYSTEM,
2275 FILESYSTEM__ASSOCIATE,
2276 &ad);
2277}
2278
2279static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2280 void *value, size_t size, int flags)
2281{
2282 struct inode *inode = dentry->d_inode;
2283 struct inode_security_struct *isec = inode->i_security;
2284 u32 newsid;
2285 int rc;
2286
2287 if (strcmp(name, XATTR_NAME_SELINUX)) {
2288 /* Not an attribute we recognize, so nothing to do. */
2289 return;
2290 }
2291
2292 rc = security_context_to_sid(value, size, &newsid);
2293 if (rc) {
2294 printk(KERN_WARNING "%s: unable to obtain SID for context "
2295 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2296 return;
2297 }
2298
2299 isec->sid = newsid;
2300 return;
2301}
2302
2303static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2304{
1da177e4
LT		 2305 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2306}
2307
2308static int selinux_inode_listxattr (struct dentry *dentry)
2309{
2310 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2311}
2312
2313static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2314{
2315 if (strcmp(name, XATTR_NAME_SELINUX)) {
2316 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2317 sizeof XATTR_SECURITY_PREFIX - 1) &&
2318 !capable(CAP_SYS_ADMIN)) {
2319 /* A different attribute in the security namespace.
2320 Restrict to administrator. */
2321 return -EPERM;
2322 }
2323
2324 /* Not an attribute we recognize, so just check the
2325 ordinary setattr permission. Might want a separate
2326 permission for removexattr. */
2327 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2328 }
2329
2330 /* No one is allowed to remove a SELinux security label.
2331 You can change the label, but all data must be labeled. */
2332 return -EACCES;
2333}
2334
8c8570fb
DK		 2335static const char *selinux_inode_xattr_getsuffix(void)
2336{
2337 return XATTR_SELINUX_SUFFIX;
2338}
2339
d381d8a9
JM		 2340/*
2341 * Copy the in-core inode security context value to the user. If the
2342 * getxattr() prior to this succeeded, check to see if we need to
2343 * canonicalize the value to be finally returned to the user.
2344 *
2345 * Permission check is handled by selinux_inode_getxattr hook.
2346 */
7306a0b9 2347static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
1da177e4
LT		 2348{
2349 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2350
8c8570fb
DK		 2351 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2352 return -EOPNOTSUPP;
d381d8a9 2353
8c8570fb 2354 return selinux_getsecurity(isec->sid, buffer, size);
1da177e4
LT		 2355}
2356
2357static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2358 const void *value, size_t size, int flags)
2359{
2360 struct inode_security_struct *isec = inode->i_security;
2361 u32 newsid;
2362 int rc;
2363
2364 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2365 return -EOPNOTSUPP;
2366
2367 if (!value || !size)
2368 return -EACCES;
2369
2370 rc = security_context_to_sid((void*)value, size, &newsid);
2371 if (rc)
2372 return rc;
2373
2374 isec->sid = newsid;
2375 return 0;
2376}
2377
2378static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2379{
2380 const int len = sizeof(XATTR_NAME_SELINUX);
2381 if (buffer && len <= buffer_size)
2382 memcpy(buffer, XATTR_NAME_SELINUX, len);
2383 return len;
2384}
2385
2386/* file security operations */
2387
2388static int selinux_file_permission(struct file *file, int mask)
2389{
7420ed23 2390 int rc;
1da177e4
LT		 2391 struct inode *inode = file->f_dentry->d_inode;
2392
2393 if (!mask) {
2394 /* No permission to check. Existence test. */
2395 return 0;
2396 }
2397
2398 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2399 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2400 mask |= MAY_APPEND;
2401
7420ed23
VY		 2402 rc = file_has_perm(current, file,
2403 file_mask_to_av(inode->i_mode, mask));
2404 if (rc)
2405 return rc;
2406
2407 return selinux_netlbl_inode_permission(inode, mask);
1da177e4
LT		 2408}
2409
2410static int selinux_file_alloc_security(struct file *file)
2411{
2412 return file_alloc_security(file);
2413}
2414
2415static void selinux_file_free_security(struct file *file)
2416{
2417 file_free_security(file);
2418}
2419
2420static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2421 unsigned long arg)
2422{
2423 int error = 0;
2424
2425 switch (cmd) {
2426 case FIONREAD:
2427 /* fall through */
2428 case FIBMAP:
2429 /* fall through */
2430 case FIGETBSZ:
2431 /* fall through */
2432 case EXT2_IOC_GETFLAGS:
2433 /* fall through */
2434 case EXT2_IOC_GETVERSION:
2435 error = file_has_perm(current, file, FILE__GETATTR);
2436 break;
2437
2438 case EXT2_IOC_SETFLAGS:
2439 /* fall through */
2440 case EXT2_IOC_SETVERSION:
2441 error = file_has_perm(current, file, FILE__SETATTR);
2442 break;
2443
2444 /* sys_ioctl() checks */
2445 case FIONBIO:
2446 /* fall through */
2447 case FIOASYNC:
2448 error = file_has_perm(current, file, 0);
2449 break;
2450
2451 case KDSKBENT:
2452 case KDSKBSENT:
2453 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2454 break;
2455
2456 /* default case assumes that the command will go
2457 * to the file's ioctl() function.
2458 */
2459 default:
2460 error = file_has_perm(current, file, FILE__IOCTL);
2461
2462 }
2463 return error;
2464}
2465
2466static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2467{
2468#ifndef CONFIG_PPC32
2469 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2470 /*
2471 * We are making executable an anonymous mapping or a
2472 * private file mapping that will also be writable.
2473 * This has an additional check.
2474 */
2475 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2476 if (rc)
2477 return rc;
2478 }
2479#endif
2480
2481 if (file) {
2482 /* read access is always possible with a mapping */
2483 u32 av = FILE__READ;
2484
2485 /* write access only matters if the mapping is shared */
2486 if (shared && (prot & PROT_WRITE))
2487 av |= FILE__WRITE;
2488
2489 if (prot & PROT_EXEC)
2490 av |= FILE__EXECUTE;
2491
2492 return file_has_perm(current, file, av);
2493 }
2494 return 0;
2495}
2496
2497static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2498 unsigned long prot, unsigned long flags)
2499{
2500 int rc;
2501
2502 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2503 if (rc)
2504 return rc;
2505
2506 if (selinux_checkreqprot)
2507 prot = reqprot;
2508
2509 return file_map_prot_check(file, prot,
2510 (flags & MAP_TYPE) == MAP_SHARED);
2511}
2512
2513static int selinux_file_mprotect(struct vm_area_struct *vma,
2514 unsigned long reqprot,
2515 unsigned long prot)
2516{
2517 int rc;
2518
2519 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2520 if (rc)
2521 return rc;
2522
2523 if (selinux_checkreqprot)
2524 prot = reqprot;
2525
2526#ifndef CONFIG_PPC32
db4c9641
SS		 2527 if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
2528 rc = 0;
2529 if (vma->vm_start >= vma->vm_mm->start_brk &&
2530 vma->vm_end <= vma->vm_mm->brk) {
2531 rc = task_has_perm(current, current,
2532 PROCESS__EXECHEAP);
2533 } else if (!vma->vm_file &&
2534 vma->vm_start <= vma->vm_mm->start_stack &&
2535 vma->vm_end >= vma->vm_mm->start_stack) {
2536 rc = task_has_perm(current, current, PROCESS__EXECSTACK);
2537 } else if (vma->vm_file && vma->anon_vma) {
2538 /*
2539 * We are making executable a file mapping that has
2540 * had some COW done. Since pages might have been
2541 * written, check ability to execute the possibly
2542 * modified content. This typically should only
2543 * occur for text relocations.
2544 */
2545 rc = file_has_perm(current, vma->vm_file,
2546 FILE__EXECMOD);
2547 }