projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
[PATCH] keys: restrict contents of /proc/keys to Viewable keys
[GitHub/mt8127/android_kernel_alcatel_ttab.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>
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License version 2,
18 * as published by the Free Software Foundation.
19 */
20
21#include <linux/config.h>
22#include <linux/module.h>
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/ptrace.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
28#include <linux/security.h>
29#include <linux/xattr.h>
30#include <linux/capability.h>
31#include <linux/unistd.h>
32#include <linux/mm.h>
33#include <linux/mman.h>
34#include <linux/slab.h>
35#include <linux/pagemap.h>
36#include <linux/swap.h>
37#include <linux/smp_lock.h>
38#include <linux/spinlock.h>
39#include <linux/syscalls.h>
40#include <linux/file.h>
41#include <linux/namei.h>
42#include <linux/mount.h>
43#include <linux/ext2_fs.h>
44#include <linux/proc_fs.h>
45#include <linux/kd.h>
46#include <linux/netfilter_ipv4.h>
47#include <linux/netfilter_ipv6.h>
48#include <linux/tty.h>
49#include <net/icmp.h>
50#include <net/ip.h> /* for sysctl_local_port_range[] */
51#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */
52#include <asm/uaccess.h>
53#include <asm/semaphore.h>
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>
1da177e4
LT		 72
73#include "avc.h"
74#include "objsec.h"
75#include "netif.h"
d28d1e08 76#include "xfrm.h"
1da177e4
LT		 77
78#define XATTR_SELINUX_SUFFIX "selinux"
79#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
80
81extern unsigned int policydb_loaded_version;
82extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
4e5ab4cb 83extern int selinux_compat_net;
1da177e4
LT		 84
85#ifdef CONFIG_SECURITY_SELINUX_DEVELOP
86int selinux_enforcing = 0;
87
88static int __init enforcing_setup(char *str)
89{
90 selinux_enforcing = simple_strtol(str,NULL,0);
91 return 1;
92}
93__setup("enforcing=", enforcing_setup);
94#endif
95
96#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
97int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
98
99static int __init selinux_enabled_setup(char *str)
100{
101 selinux_enabled = simple_strtol(str, NULL, 0);
102 return 1;
103}
104__setup("selinux=", selinux_enabled_setup);
30d55280
SS		 105#else
106int selinux_enabled = 1;
1da177e4
LT		 107#endif
108
109/* Original (dummy) security module. */
110static struct security_operations *original_ops = NULL;
111
112/* Minimal support for a secondary security module,
113 just to allow the use of the dummy or capability modules.
114 The owlsm module can alternatively be used as a secondary
115 module as long as CONFIG_OWLSM_FD is not enabled. */
116static struct security_operations *secondary_ops = NULL;
117
118/* Lists of inode and superblock security structures initialized
119 before the policy was loaded. */
120static LIST_HEAD(superblock_security_head);
121static DEFINE_SPINLOCK(sb_security_lock);
122
7cae7e26
JM		 123static kmem_cache_t *sel_inode_cache;
124
8c8570fb
DK		 125/* Return security context for a given sid or just the context
126 length if the buffer is null or length is 0 */
127static int selinux_getsecurity(u32 sid, void *buffer, size_t size)
128{
129 char *context;
130 unsigned len;
131 int rc;
132
133 rc = security_sid_to_context(sid, &context, &len);
134 if (rc)
135 return rc;
136
137 if (!buffer || !size)
138 goto getsecurity_exit;
139
140 if (size < len) {
141 len = -ERANGE;
142 goto getsecurity_exit;
143 }
144 memcpy(buffer, context, len);
145
146getsecurity_exit:
147 kfree(context);
148 return len;
149}
150
1da177e4
LT		 151/* Allocate and free functions for each kind of security blob. */
152
153static int task_alloc_security(struct task_struct *task)
154{
155 struct task_security_struct *tsec;
156
89d155ef 157 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4
LT		 158 if (!tsec)
159 return -ENOMEM;
160
1da177e4
LT		 161 tsec->task = task;
162 tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
163 task->security = tsec;
164
165 return 0;
166}
167
168static void task_free_security(struct task_struct *task)
169{
170 struct task_security_struct *tsec = task->security;
1da177e4
LT		 171 task->security = NULL;
172 kfree(tsec);
173}
174
175static int inode_alloc_security(struct inode *inode)
176{
177 struct task_security_struct *tsec = current->security;
178 struct inode_security_struct *isec;
179
7cae7e26 180 isec = kmem_cache_alloc(sel_inode_cache, SLAB_KERNEL);
1da177e4
LT		 181 if (!isec)
182 return -ENOMEM;
183
7cae7e26 184 memset(isec, 0, sizeof(*isec));
1da177e4
LT		 185 init_MUTEX(&isec->sem);
186 INIT_LIST_HEAD(&isec->list);
1da177e4
LT		 187 isec->inode = inode;
188 isec->sid = SECINITSID_UNLABELED;
189 isec->sclass = SECCLASS_FILE;
9ac49d22 190 isec->task_sid = tsec->sid;
1da177e4
LT		 191 inode->i_security = isec;
192
193 return 0;
194}
195
196static void inode_free_security(struct inode *inode)
197{
198 struct inode_security_struct *isec = inode->i_security;
199 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
200
1da177e4
LT		 201 spin_lock(&sbsec->isec_lock);
202 if (!list_empty(&isec->list))
203 list_del_init(&isec->list);
204 spin_unlock(&sbsec->isec_lock);
205
206 inode->i_security = NULL;
7cae7e26 207 kmem_cache_free(sel_inode_cache, isec);
1da177e4
LT		 208}
209
210static int file_alloc_security(struct file *file)
211{
212 struct task_security_struct *tsec = current->security;
213 struct file_security_struct *fsec;
214
26d2a4be 215 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
1da177e4
LT		 216 if (!fsec)
217 return -ENOMEM;
218
1da177e4 219 fsec->file = file;
9ac49d22
SS		 220 fsec->sid = tsec->sid;
221 fsec->fown_sid = tsec->sid;
1da177e4
LT		 222 file->f_security = fsec;
223
224 return 0;
225}
226
227static void file_free_security(struct file *file)
228{
229 struct file_security_struct *fsec = file->f_security;
1da177e4
LT		 230 file->f_security = NULL;
231 kfree(fsec);
232}
233
234static int superblock_alloc_security(struct super_block *sb)
235{
236 struct superblock_security_struct *sbsec;
237
89d155ef 238 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT		 239 if (!sbsec)
240 return -ENOMEM;
241
1da177e4
LT		 242 init_MUTEX(&sbsec->sem);
243 INIT_LIST_HEAD(&sbsec->list);
244 INIT_LIST_HEAD(&sbsec->isec_head);
245 spin_lock_init(&sbsec->isec_lock);
1da177e4
LT		 246 sbsec->sb = sb;
247 sbsec->sid = SECINITSID_UNLABELED;
248 sbsec->def_sid = SECINITSID_FILE;
249 sb->s_security = sbsec;
250
251 return 0;
252}
253
254static void superblock_free_security(struct super_block *sb)
255{
256 struct superblock_security_struct *sbsec = sb->s_security;
257
1da177e4
LT		 258 spin_lock(&sb_security_lock);
259 if (!list_empty(&sbsec->list))
260 list_del_init(&sbsec->list);
261 spin_unlock(&sb_security_lock);
262
263 sb->s_security = NULL;
264 kfree(sbsec);
265}
266
7d877f3b 267static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
1da177e4
LT		 268{
269 struct sk_security_struct *ssec;
270
271 if (family != PF_UNIX)
272 return 0;
273
89d155ef 274 ssec = kzalloc(sizeof(*ssec), priority);
1da177e4
LT		 275 if (!ssec)
276 return -ENOMEM;
277
1da177e4
LT		 278 ssec->sk = sk;
279 ssec->peer_sid = SECINITSID_UNLABELED;
280 sk->sk_security = ssec;
281
282 return 0;
283}
284
285static void sk_free_security(struct sock *sk)
286{
287 struct sk_security_struct *ssec = sk->sk_security;
288
9ac49d22 289 if (sk->sk_family != PF_UNIX)
1da177e4
LT		 290 return;
291
292 sk->sk_security = NULL;
293 kfree(ssec);
294}
1da177e4
LT		 295
296/* The security server must be initialized before
297 any labeling or access decisions can be provided. */
298extern int ss_initialized;
299
300/* The file system's label must be initialized prior to use. */
301
302static char *labeling_behaviors[6] = {
303 "uses xattr",
304 "uses transition SIDs",
305 "uses task SIDs",
306 "uses genfs_contexts",
307 "not configured for labeling",
308 "uses mountpoint labeling",
309};
310
311static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
312
313static inline int inode_doinit(struct inode *inode)
314{
315 return inode_doinit_with_dentry(inode, NULL);
316}
317
318enum {
319 Opt_context = 1,
320 Opt_fscontext = 2,
321 Opt_defcontext = 4,
322};
323
324static match_table_t tokens = {
325 {Opt_context, "context=%s"},
326 {Opt_fscontext, "fscontext=%s"},
327 {Opt_defcontext, "defcontext=%s"},
328};
329
330#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
331
332static int try_context_mount(struct super_block *sb, void *data)
333{
334 char *context = NULL, *defcontext = NULL;
335 const char *name;
336 u32 sid;
337 int alloc = 0, rc = 0, seen = 0;
338 struct task_security_struct *tsec = current->security;
339 struct superblock_security_struct *sbsec = sb->s_security;
340
341 if (!data)
342 goto out;
343
344 name = sb->s_type->name;
345
346 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
347
348 /* NFS we understand. */
349 if (!strcmp(name, "nfs")) {
350 struct nfs_mount_data *d = data;
351
352 if (d->version < NFS_MOUNT_VERSION)
353 goto out;
354
355 if (d->context[0]) {
356 context = d->context;
357 seen |= Opt_context;
358 }
359 } else
360 goto out;
361
362 } else {
363 /* Standard string-based options. */
364 char *p, *options = data;
365
366 while ((p = strsep(&options, ",")) != NULL) {
367 int token;
368 substring_t args[MAX_OPT_ARGS];
369
370 if (!*p)
371 continue;
372
373 token = match_token(p, tokens, args);
374
375 switch (token) {
376 case Opt_context:
377 if (seen) {
378 rc = -EINVAL;
379 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
380 goto out_free;
381 }
382 context = match_strdup(&args[0]);
383 if (!context) {
384 rc = -ENOMEM;
385 goto out_free;
386 }
387 if (!alloc)
388 alloc = 1;
389 seen |= Opt_context;
390 break;
391
392 case Opt_fscontext:
393 if (seen & (Opt_context|Opt_fscontext)) {
394 rc = -EINVAL;
395 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
396 goto out_free;
397 }
398 context = match_strdup(&args[0]);
399 if (!context) {
400 rc = -ENOMEM;
401 goto out_free;
402 }
403 if (!alloc)
404 alloc = 1;
405 seen |= Opt_fscontext;
406 break;
407
408 case Opt_defcontext:
409 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
410 rc = -EINVAL;
411 printk(KERN_WARNING "SELinux: "
412 "defcontext option is invalid "
413 "for this filesystem type\n");
414 goto out_free;
415 }
416 if (seen & (Opt_context|Opt_defcontext)) {
417 rc = -EINVAL;
418 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
419 goto out_free;
420 }
421 defcontext = match_strdup(&args[0]);
422 if (!defcontext) {
423 rc = -ENOMEM;
424 goto out_free;
425 }
426 if (!alloc)
427 alloc = 1;
428 seen |= Opt_defcontext;
429 break;
430
431 default:
432 rc = -EINVAL;
433 printk(KERN_WARNING "SELinux: unknown mount "
434 "option\n");
435 goto out_free;
436
437 }
438 }
439 }
440
441 if (!seen)
442 goto out;
443
444 if (context) {
445 rc = security_context_to_sid(context, strlen(context), &sid);
446 if (rc) {
447 printk(KERN_WARNING "SELinux: security_context_to_sid"
448 "(%s) failed for (dev %s, type %s) errno=%d\n",
449 context, sb->s_id, name, rc);
450 goto out_free;
451 }
452
453 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
454 FILESYSTEM__RELABELFROM, NULL);
455 if (rc)
456 goto out_free;
457
458 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
459 FILESYSTEM__RELABELTO, NULL);
460 if (rc)
461 goto out_free;
462
463 sbsec->sid = sid;
464
465 if (seen & Opt_context)
466 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
467 }
468
469 if (defcontext) {
470 rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
471 if (rc) {
472 printk(KERN_WARNING "SELinux: security_context_to_sid"
473 "(%s) failed for (dev %s, type %s) errno=%d\n",
474 defcontext, sb->s_id, name, rc);
475 goto out_free;
476 }
477
478 if (sid == sbsec->def_sid)
479 goto out_free;
480
481 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
482 FILESYSTEM__RELABELFROM, NULL);
483 if (rc)
484 goto out_free;
485
486 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
487 FILESYSTEM__ASSOCIATE, NULL);
488 if (rc)
489 goto out_free;
490
491 sbsec->def_sid = sid;
492 }
493
494out_free:
495 if (alloc) {
496 kfree(context);
497 kfree(defcontext);
498 }
499out:
500 return rc;
501}
502
503static int superblock_doinit(struct super_block *sb, void *data)
504{
505 struct superblock_security_struct *sbsec = sb->s_security;
506 struct dentry *root = sb->s_root;
507 struct inode *inode = root->d_inode;
508 int rc = 0;
509
510 down(&sbsec->sem);
511 if (sbsec->initialized)
512 goto out;
513
514 if (!ss_initialized) {
515 /* Defer initialization until selinux_complete_init,
516 after the initial policy is loaded and the security
517 server is ready to handle calls. */
518 spin_lock(&sb_security_lock);
519 if (list_empty(&sbsec->list))
520 list_add(&sbsec->list, &superblock_security_head);
521 spin_unlock(&sb_security_lock);
522 goto out;
523 }
524
525 /* Determine the labeling behavior to use for this filesystem type. */
526 rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
527 if (rc) {
528 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
529 __FUNCTION__, sb->s_type->name, rc);
530 goto out;
531 }
532
533 rc = try_context_mount(sb, data);
534 if (rc)
535 goto out;
536
537 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
538 /* Make sure that the xattr handler exists and that no
539 error other than -ENODATA is returned by getxattr on
540 the root directory. -ENODATA is ok, as this may be
541 the first boot of the SELinux kernel before we have
542 assigned xattr values to the filesystem. */
543 if (!inode->i_op->getxattr) {
544 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
545 "xattr support\n", sb->s_id, sb->s_type->name);
546 rc = -EOPNOTSUPP;
547 goto out;
548 }
549 rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
550 if (rc < 0 && rc != -ENODATA) {
551 if (rc == -EOPNOTSUPP)
552 printk(KERN_WARNING "SELinux: (dev %s, type "
553 "%s) has no security xattr handler\n",
554 sb->s_id, sb->s_type->name);
555 else
556 printk(KERN_WARNING "SELinux: (dev %s, type "
557 "%s) getxattr errno %d\n", sb->s_id,
558 sb->s_type->name, -rc);
559 goto out;
560 }
561 }
562
563 if (strcmp(sb->s_type->name, "proc") == 0)
564 sbsec->proc = 1;
565
566 sbsec->initialized = 1;
567
568 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
569 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
570 sb->s_id, sb->s_type->name);
571 }
572 else {
573 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
574 sb->s_id, sb->s_type->name,
575 labeling_behaviors[sbsec->behavior-1]);
576 }
577
578 /* Initialize the root inode. */
579 rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
580
581 /* Initialize any other inodes associated with the superblock, e.g.
582 inodes created prior to initial policy load or inodes created
583 during get_sb by a pseudo filesystem that directly
584 populates itself. */
585 spin_lock(&sbsec->isec_lock);
586next_inode:
587 if (!list_empty(&sbsec->isec_head)) {
588 struct inode_security_struct *isec =
589 list_entry(sbsec->isec_head.next,
590 struct inode_security_struct, list);
591 struct inode *inode = isec->inode;
592 spin_unlock(&sbsec->isec_lock);
593 inode = igrab(inode);
594 if (inode) {
595 if (!IS_PRIVATE (inode))
596 inode_doinit(inode);
597 iput(inode);
598 }
599 spin_lock(&sbsec->isec_lock);
600 list_del_init(&isec->list);
601 goto next_inode;
602 }
603 spin_unlock(&sbsec->isec_lock);
604out:
605 up(&sbsec->sem);
606 return rc;
607}
608
609static inline u16 inode_mode_to_security_class(umode_t mode)
610{
611 switch (mode & S_IFMT) {
612 case S_IFSOCK:
613 return SECCLASS_SOCK_FILE;
614 case S_IFLNK:
615 return SECCLASS_LNK_FILE;
616 case S_IFREG:
617 return SECCLASS_FILE;
618 case S_IFBLK:
619 return SECCLASS_BLK_FILE;
620 case S_IFDIR:
621 return SECCLASS_DIR;
622 case S_IFCHR:
623 return SECCLASS_CHR_FILE;
624 case S_IFIFO:
625 return SECCLASS_FIFO_FILE;
626
627 }
628
629 return SECCLASS_FILE;
630}
631
13402580
JM		 632static inline int default_protocol_stream(int protocol)
633{
634 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
635}
636
637static inline int default_protocol_dgram(int protocol)
638{
639 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
640}
641
1da177e4
LT		 642static inline u16 socket_type_to_security_class(int family, int type, int protocol)
643{
644 switch (family) {
645 case PF_UNIX:
646 switch (type) {
647 case SOCK_STREAM:
648 case SOCK_SEQPACKET:
649 return SECCLASS_UNIX_STREAM_SOCKET;
650 case SOCK_DGRAM:
651 return SECCLASS_UNIX_DGRAM_SOCKET;
652 }
653 break;
654 case PF_INET:
655 case PF_INET6:
656 switch (type) {
657 case SOCK_STREAM:
13402580
JM		 658 if (default_protocol_stream(protocol))
659 return SECCLASS_TCP_SOCKET;
660 else
661 return SECCLASS_RAWIP_SOCKET;
1da177e4 662 case SOCK_DGRAM:
13402580
JM		 663 if (default_protocol_dgram(protocol))
664 return SECCLASS_UDP_SOCKET;
665 else
666 return SECCLASS_RAWIP_SOCKET;
667 default:
1da177e4
LT		 668 return SECCLASS_RAWIP_SOCKET;
669 }
670 break;
671 case PF_NETLINK:
672 switch (protocol) {
673 case NETLINK_ROUTE:
674 return SECCLASS_NETLINK_ROUTE_SOCKET;
675 case NETLINK_FIREWALL:
676 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 677 case NETLINK_INET_DIAG:
1da177e4
LT		 678 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
679 case NETLINK_NFLOG:
680 return SECCLASS_NETLINK_NFLOG_SOCKET;
681 case NETLINK_XFRM:
682 return SECCLASS_NETLINK_XFRM_SOCKET;
683 case NETLINK_SELINUX:
684 return SECCLASS_NETLINK_SELINUX_SOCKET;
685 case NETLINK_AUDIT:
686 return SECCLASS_NETLINK_AUDIT_SOCKET;
687 case NETLINK_IP6_FW:
688 return SECCLASS_NETLINK_IP6FW_SOCKET;
689 case NETLINK_DNRTMSG:
690 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM		 691 case NETLINK_KOBJECT_UEVENT:
692 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT		 693 default:
694 return SECCLASS_NETLINK_SOCKET;
695 }
696 case PF_PACKET:
697 return SECCLASS_PACKET_SOCKET;
698 case PF_KEY:
699 return SECCLASS_KEY_SOCKET;
3e3ff15e
CP		 700 case PF_APPLETALK:
701 return SECCLASS_APPLETALK_SOCKET;
1da177e4
LT		 702 }
703
704 return SECCLASS_SOCKET;
705}
706
707#ifdef CONFIG_PROC_FS
708static int selinux_proc_get_sid(struct proc_dir_entry *de,
709 u16 tclass,
710 u32 *sid)
711{
712 int buflen, rc;
713 char *buffer, *path, *end;
714
715 buffer = (char*)__get_free_page(GFP_KERNEL);
716 if (!buffer)
717 return -ENOMEM;
718
719 buflen = PAGE_SIZE;
720 end = buffer+buflen;
721 *--end = '\0';
722 buflen--;
723 path = end-1;
724 *path = '/';
725 while (de && de != de->parent) {
726 buflen -= de->namelen + 1;
727 if (buflen < 0)
728 break;
729 end -= de->namelen;
730 memcpy(end, de->name, de->namelen);
731 *--end = '/';
732 path = end;
733 de = de->parent;
734 }
735 rc = security_genfs_sid("proc", path, tclass, sid);
736 free_page((unsigned long)buffer);
737 return rc;
738}
739#else
740static int selinux_proc_get_sid(struct proc_dir_entry *de,
741 u16 tclass,
742 u32 *sid)
743{
744 return -EINVAL;
745}
746#endif
747
748/* The inode's security attributes must be initialized before first use. */
749static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
750{
751 struct superblock_security_struct *sbsec = NULL;
752 struct inode_security_struct *isec = inode->i_security;
753 u32 sid;
754 struct dentry *dentry;
755#define INITCONTEXTLEN 255
756 char *context = NULL;
757 unsigned len = 0;
758 int rc = 0;
759 int hold_sem = 0;
760
761 if (isec->initialized)
762 goto out;
763
764 down(&isec->sem);
765 hold_sem = 1;
766 if (isec->initialized)
767 goto out;
768
769 sbsec = inode->i_sb->s_security;
770 if (!sbsec->initialized) {
771 /* Defer initialization until selinux_complete_init,
772 after the initial policy is loaded and the security
773 server is ready to handle calls. */
774 spin_lock(&sbsec->isec_lock);
775 if (list_empty(&isec->list))
776 list_add(&isec->list, &sbsec->isec_head);
777 spin_unlock(&sbsec->isec_lock);
778 goto out;
779 }
780
781 switch (sbsec->behavior) {
782 case SECURITY_FS_USE_XATTR:
783 if (!inode->i_op->getxattr) {
784 isec->sid = sbsec->def_sid;
785 break;
786 }
787
788 /* Need a dentry, since the xattr API requires one.
789 Life would be simpler if we could just pass the inode. */
790 if (opt_dentry) {
791 /* Called from d_instantiate or d_splice_alias. */
792 dentry = dget(opt_dentry);
793 } else {
794 /* Called from selinux_complete_init, try to find a dentry. */
795 dentry = d_find_alias(inode);
796 }
797 if (!dentry) {
798 printk(KERN_WARNING "%s: no dentry for dev=%s "
799 "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
800 inode->i_ino);
801 goto out;
802 }
803
804 len = INITCONTEXTLEN;
805 context = kmalloc(len, GFP_KERNEL);
806 if (!context) {
807 rc = -ENOMEM;
808 dput(dentry);
809 goto out;
810 }
811 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
812 context, len);
813 if (rc == -ERANGE) {
814 /* Need a larger buffer. Query for the right size. */
815 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
816 NULL, 0);
817 if (rc < 0) {
818 dput(dentry);
819 goto out;
820 }
821 kfree(context);
822 len = rc;
823 context = kmalloc(len, GFP_KERNEL);
824 if (!context) {
825 rc = -ENOMEM;
826 dput(dentry);
827 goto out;
828 }
829 rc = inode->i_op->getxattr(dentry,
830 XATTR_NAME_SELINUX,
831 context, len);
832 }
833 dput(dentry);
834 if (rc < 0) {
835 if (rc != -ENODATA) {
836 printk(KERN_WARNING "%s: getxattr returned "
837 "%d for dev=%s ino=%ld\n", __FUNCTION__,
838 -rc, inode->i_sb->s_id, inode->i_ino);
839 kfree(context);
840 goto out;
841 }
842 /* Map ENODATA to the default file SID */
843 sid = sbsec->def_sid;
844 rc = 0;
845 } else {
f5c1d5b2
JM		 846 rc = security_context_to_sid_default(context, rc, &sid,
847 sbsec->def_sid);
1da177e4
LT		 848 if (rc) {
849 printk(KERN_WARNING "%s: context_to_sid(%s) "
850 "returned %d for dev=%s ino=%ld\n",
851 __FUNCTION__, context, -rc,
852 inode->i_sb->s_id, inode->i_ino);
853 kfree(context);
854 /* Leave with the unlabeled SID */
855 rc = 0;
856 break;
857 }
858 }
859 kfree(context);
860 isec->sid = sid;
861 break;
862 case SECURITY_FS_USE_TASK:
863 isec->sid = isec->task_sid;
864 break;
865 case SECURITY_FS_USE_TRANS:
866 /* Default to the fs SID. */
867 isec->sid = sbsec->sid;
868
869 /* Try to obtain a transition SID. */
870 isec->sclass = inode_mode_to_security_class(inode->i_mode);
871 rc = security_transition_sid(isec->task_sid,
872 sbsec->sid,
873 isec->sclass,
874 &sid);
875 if (rc)
876 goto out;
877 isec->sid = sid;
878 break;
879 default:
880 /* Default to the fs SID. */
881 isec->sid = sbsec->sid;
882
883 if (sbsec->proc) {
884 struct proc_inode *proci = PROC_I(inode);
885 if (proci->pde) {
886 isec->sclass = inode_mode_to_security_class(inode->i_mode);
887 rc = selinux_proc_get_sid(proci->pde,
888 isec->sclass,
889 &sid);
890 if (rc)
891 goto out;
892 isec->sid = sid;
893 }
894 }
895 break;
896 }
897
898 isec->initialized = 1;
899
900out:
901 if (isec->sclass == SECCLASS_FILE)
902 isec->sclass = inode_mode_to_security_class(inode->i_mode);
903
904 if (hold_sem)
905 up(&isec->sem);
906 return rc;
907}
908
909/* Convert a Linux signal to an access vector. */
910static inline u32 signal_to_av(int sig)
911{
912 u32 perm = 0;
913
914 switch (sig) {
915 case SIGCHLD:
916 /* Commonly granted from child to parent. */
917 perm = PROCESS__SIGCHLD;
918 break;
919 case SIGKILL:
920 /* Cannot be caught or ignored */
921 perm = PROCESS__SIGKILL;
922 break;
923 case SIGSTOP:
924 /* Cannot be caught or ignored */
925 perm = PROCESS__SIGSTOP;
926 break;
927 default:
928 /* All other signals. */
929 perm = PROCESS__SIGNAL;
930 break;
931 }
932
933 return perm;
934}
935
936/* Check permission betweeen a pair of tasks, e.g. signal checks,
937 fork check, ptrace check, etc. */
938static int task_has_perm(struct task_struct *tsk1,
939 struct task_struct *tsk2,
940 u32 perms)
941{
942 struct task_security_struct *tsec1, *tsec2;
943
944 tsec1 = tsk1->security;
945 tsec2 = tsk2->security;
946 return avc_has_perm(tsec1->sid, tsec2->sid,
947 SECCLASS_PROCESS, perms, NULL);
948}
949
950/* Check whether a task is allowed to use a capability. */
951static int task_has_capability(struct task_struct *tsk,
952 int cap)
953{
954 struct task_security_struct *tsec;
955 struct avc_audit_data ad;
956
957 tsec = tsk->security;
958
959 AVC_AUDIT_DATA_INIT(&ad,CAP);
960 ad.tsk = tsk;
961 ad.u.cap = cap;
962
963 return avc_has_perm(tsec->sid, tsec->sid,
964 SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
965}
966
967/* Check whether a task is allowed to use a system operation. */
968static int task_has_system(struct task_struct *tsk,
969 u32 perms)
970{
971 struct task_security_struct *tsec;
972
973 tsec = tsk->security;
974
975 return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
976 SECCLASS_SYSTEM, perms, NULL);
977}
978
979/* Check whether a task has a particular permission to an inode.
980 The 'adp' parameter is optional and allows other audit
981 data to be passed (e.g. the dentry). */
982static int inode_has_perm(struct task_struct *tsk,
983 struct inode *inode,
984 u32 perms,
985 struct avc_audit_data *adp)
986{
987 struct task_security_struct *tsec;
988 struct inode_security_struct *isec;
989 struct avc_audit_data ad;
990
991 tsec = tsk->security;
992 isec = inode->i_security;
993
994 if (!adp) {
995 adp = &ad;
996 AVC_AUDIT_DATA_INIT(&ad, FS);
997 ad.u.fs.inode = inode;
998 }
999
1000 return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
1001}
1002
1003/* Same as inode_has_perm, but pass explicit audit data containing
1004 the dentry to help the auditing code to more easily generate the
1005 pathname if needed. */
1006static inline int dentry_has_perm(struct task_struct *tsk,
1007 struct vfsmount *mnt,
1008 struct dentry *dentry,
1009 u32 av)
1010{
1011 struct inode *inode = dentry->d_inode;
1012 struct avc_audit_data ad;
1013 AVC_AUDIT_DATA_INIT(&ad,FS);
1014 ad.u.fs.mnt = mnt;
1015 ad.u.fs.dentry = dentry;
1016 return inode_has_perm(tsk, inode, av, &ad);
1017}
1018
1019/* Check whether a task can use an open file descriptor to
1020 access an inode in a given way. Check access to the
1021 descriptor itself, and then use dentry_has_perm to
1022 check a particular permission to the file.
1023 Access to the descriptor is implicitly granted if it
1024 has the same SID as the process. If av is zero, then
1025 access to the file is not checked, e.g. for cases
1026 where only the descriptor is affected like seek. */
858119e1 1027static int file_has_perm(struct task_struct *tsk,
1da177e4
LT		 1028 struct file *file,
1029 u32 av)
1030{
1031 struct task_security_struct *tsec = tsk->security;
1032 struct file_security_struct *fsec = file->f_security;
1033 struct vfsmount *mnt = file->f_vfsmnt;
1034 struct dentry *dentry = file->f_dentry;
1035 struct inode *inode = dentry->d_inode;
1036 struct avc_audit_data ad;
1037 int rc;
1038
1039 AVC_AUDIT_DATA_INIT(&ad, FS);
1040 ad.u.fs.mnt = mnt;
1041 ad.u.fs.dentry = dentry;
1042
1043 if (tsec->sid != fsec->sid) {
1044 rc = avc_has_perm(tsec->sid, fsec->sid,
1045 SECCLASS_FD,
1046 FD__USE,
1047 &ad);
1048 if (rc)
1049 return rc;
1050 }
1051
1052 /* av is zero if only checking access to the descriptor. */
1053 if (av)
1054 return inode_has_perm(tsk, inode, av, &ad);
1055
1056 return 0;
1057}
1058
1059/* Check whether a task can create a file. */
1060static int may_create(struct inode *dir,
1061 struct dentry *dentry,
1062 u16 tclass)
1063{
1064 struct task_security_struct *tsec;
1065 struct inode_security_struct *dsec;
1066 struct superblock_security_struct *sbsec;
1067 u32 newsid;
1068 struct avc_audit_data ad;
1069 int rc;
1070
1071 tsec = current->security;
1072 dsec = dir->i_security;
1073 sbsec = dir->i_sb->s_security;
1074
1075 AVC_AUDIT_DATA_INIT(&ad, FS);
1076 ad.u.fs.dentry = dentry;
1077
1078 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1079 DIR__ADD_NAME | DIR__SEARCH,
1080 &ad);
1081 if (rc)
1082 return rc;
1083
1084 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1085 newsid = tsec->create_sid;
1086 } else {
1087 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1088 &newsid);
1089 if (rc)
1090 return rc;
1091 }
1092
1093 rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1094 if (rc)
1095 return rc;
1096
1097 return avc_has_perm(newsid, sbsec->sid,
1098 SECCLASS_FILESYSTEM,
1099 FILESYSTEM__ASSOCIATE, &ad);
1100}
1101
1102#define MAY_LINK 0
1103#define MAY_UNLINK 1
1104#define MAY_RMDIR 2
1105
1106/* Check whether a task can link, unlink, or rmdir a file/directory. */
1107static int may_link(struct inode *dir,
1108 struct dentry *dentry,
1109 int kind)
1110
1111{
1112 struct task_security_struct *tsec;
1113 struct inode_security_struct *dsec, *isec;
1114 struct avc_audit_data ad;
1115 u32 av;
1116 int rc;
1117
1118 tsec = current->security;
1119 dsec = dir->i_security;
1120 isec = dentry->d_inode->i_security;
1121
1122 AVC_AUDIT_DATA_INIT(&ad, FS);
1123 ad.u.fs.dentry = dentry;
1124
1125 av = DIR__SEARCH;
1126 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1127 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1128 if (rc)
1129 return rc;
1130
1131 switch (kind) {
1132 case MAY_LINK:
1133 av = FILE__LINK;
1134 break;
1135 case MAY_UNLINK:
1136 av = FILE__UNLINK;
1137 break;
1138 case MAY_RMDIR:
1139 av = DIR__RMDIR;
1140 break;
1141 default:
1142 printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind);
1143 return 0;
1144 }
1145
1146 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1147 return rc;
1148}
1149
1150static inline int may_rename(struct inode *old_dir,
1151 struct dentry *old_dentry,
1152 struct inode *new_dir,
1153 struct dentry *new_dentry)
1154{
1155 struct task_security_struct *tsec;
1156 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1157 struct avc_audit_data ad;
1158 u32 av;
1159 int old_is_dir, new_is_dir;
1160 int rc;
1161
1162 tsec = current->security;
1163 old_dsec = old_dir->i_security;
1164 old_isec = old_dentry->d_inode->i_security;
1165 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1166 new_dsec = new_dir->i_security;
1167
1168 AVC_AUDIT_DATA_INIT(&ad, FS);
1169
1170 ad.u.fs.dentry = old_dentry;
1171 rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1172 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1173 if (rc)
1174 return rc;
1175 rc = avc_has_perm(tsec->sid, old_isec->sid,
1176 old_isec->sclass, FILE__RENAME, &ad);
1177 if (rc)
1178 return rc;
1179 if (old_is_dir && new_dir != old_dir) {
1180 rc = avc_has_perm(tsec->sid, old_isec->sid,
1181 old_isec->sclass, DIR__REPARENT, &ad);
1182 if (rc)
1183 return rc;
1184 }
1185
1186 ad.u.fs.dentry = new_dentry;
1187 av = DIR__ADD_NAME | DIR__SEARCH;
1188 if (new_dentry->d_inode)
1189 av |= DIR__REMOVE_NAME;
1190 rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1191 if (rc)
1192 return rc;
1193 if (new_dentry->d_inode) {
1194 new_isec = new_dentry->d_inode->i_security;
1195 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1196 rc = avc_has_perm(tsec->sid, new_isec->sid,
1197 new_isec->sclass,
1198 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1199 if (rc)
1200 return rc;
1201 }
1202
1203 return 0;
1204}
1205
1206/* Check whether a task can perform a filesystem operation. */
1207static int superblock_has_perm(struct task_struct *tsk,
1208 struct super_block *sb,
1209 u32 perms,
1210 struct avc_audit_data *ad)
1211{
1212 struct task_security_struct *tsec;
1213 struct superblock_security_struct *sbsec;
1214
1215 tsec = tsk->security;
1216 sbsec = sb->s_security;
1217 return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1218 perms, ad);
1219}
1220
1221/* Convert a Linux mode and permission mask to an access vector. */
1222static inline u32 file_mask_to_av(int mode, int mask)
1223{
1224 u32 av = 0;
1225
1226 if ((mode & S_IFMT) != S_IFDIR) {
1227 if (mask & MAY_EXEC)
1228 av |= FILE__EXECUTE;
1229 if (mask & MAY_READ)
1230 av |= FILE__READ;
1231
1232 if (mask & MAY_APPEND)
1233 av |= FILE__APPEND;
1234 else if (mask & MAY_WRITE)
1235 av |= FILE__WRITE;
1236
1237 } else {
1238 if (mask & MAY_EXEC)
1239 av |= DIR__SEARCH;
1240 if (mask & MAY_WRITE)
1241 av |= DIR__WRITE;
1242 if (mask & MAY_READ)
1243 av |= DIR__READ;
1244 }
1245
1246 return av;
1247}
1248
1249/* Convert a Linux file to an access vector. */
1250static inline u32 file_to_av(struct file *file)
1251{
1252 u32 av = 0;
1253
1254 if (file->f_mode & FMODE_READ)
1255 av |= FILE__READ;
1256 if (file->f_mode & FMODE_WRITE) {
1257 if (file->f_flags & O_APPEND)
1258 av |= FILE__APPEND;
1259 else
1260 av |= FILE__WRITE;
1261 }
1262
1263 return av;
1264}
1265
1266/* Set an inode's SID to a specified value. */
1267static int inode_security_set_sid(struct inode *inode, u32 sid)
1268{
1269 struct inode_security_struct *isec = inode->i_security;
1270 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
1271
1272 if (!sbsec->initialized) {
1273 /* Defer initialization to selinux_complete_init. */
1274 return 0;
1275 }
1276
1277 down(&isec->sem);
1278 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1279 isec->sid = sid;
1280 isec->initialized = 1;
1281 up(&isec->sem);
1282 return 0;
1283}
1284
1da177e4
LT		 1285/* Hook functions begin here. */
1286
1287static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1288{
1289 struct task_security_struct *psec = parent->security;
1290 struct task_security_struct *csec = child->security;
1291 int rc;
1292
1293 rc = secondary_ops->ptrace(parent,child);
1294 if (rc)
1295 return rc;
1296
1297 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1298 /* Save the SID of the tracing process for later use in apply_creds. */
341c2d80 1299 if (!(child->ptrace & PT_PTRACED) && !rc)
1da177e4
LT		 1300 csec->ptrace_sid = psec->sid;
1301 return rc;
1302}
1303
1304static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1305 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1306{
1307 int error;
1308
1309 error = task_has_perm(current, target, PROCESS__GETCAP);
1310 if (error)
1311 return error;
1312
1313 return secondary_ops->capget(target, effective, inheritable, permitted);
1314}
1315
1316static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1317 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1318{
1319 int error;
1320
1321 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1322 if (error)
1323 return error;
1324
1325 return task_has_perm(current, target, PROCESS__SETCAP);
1326}
1327
1328static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1329 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1330{
1331 secondary_ops->capset_set(target, effective, inheritable, permitted);
1332}
1333
1334static int selinux_capable(struct task_struct *tsk, int cap)
1335{
1336 int rc;
1337
1338 rc = secondary_ops->capable(tsk, cap);
1339 if (rc)
1340 return rc;
1341
1342 return task_has_capability(tsk,cap);
1343}
1344
1345static int selinux_sysctl(ctl_table *table, int op)
1346{
1347 int error = 0;
1348 u32 av;
1349 struct task_security_struct *tsec;
1350 u32 tsid;
1351 int rc;
1352
1353 rc = secondary_ops->sysctl(table, op);
1354 if (rc)
1355 return rc;
1356
1357 tsec = current->security;
1358
1359 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1360 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1361 if (rc) {
1362 /* Default to the well-defined sysctl SID. */
1363 tsid = SECINITSID_SYSCTL;
1364 }
1365
1366 /* The op values are "defined" in sysctl.c, thereby creating
1367 * a bad coupling between this module and sysctl.c */
1368 if(op == 001) {
1369 error = avc_has_perm(tsec->sid, tsid,
1370 SECCLASS_DIR, DIR__SEARCH, NULL);
1371 } else {
1372 av = 0;
1373 if (op & 004)
1374 av |= FILE__READ;
1375 if (op & 002)
1376 av |= FILE__WRITE;
1377 if (av)
1378 error = avc_has_perm(tsec->sid, tsid,
1379 SECCLASS_FILE, av, NULL);
1380 }
1381
1382 return error;
1383}
1384
1385static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1386{
1387 int rc = 0;
1388
1389 if (!sb)
1390 return 0;
1391
1392 switch (cmds) {
1393 case Q_SYNC:
1394 case Q_QUOTAON:
1395 case Q_QUOTAOFF:
1396 case Q_SETINFO:
1397 case Q_SETQUOTA:
1398 rc = superblock_has_perm(current,
1399 sb,
1400 FILESYSTEM__QUOTAMOD, NULL);
1401 break;
1402 case Q_GETFMT:
1403 case Q_GETINFO:
1404 case Q_GETQUOTA:
1405 rc = superblock_has_perm(current,
1406 sb,
1407 FILESYSTEM__QUOTAGET, NULL);
1408 break;
1409 default:
1410 rc = 0; /* let the kernel handle invalid cmds */
1411 break;
1412 }
1413 return rc;
1414}
1415
1416static int selinux_quota_on(struct dentry *dentry)
1417{
1418 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1419}
1420
1421static int selinux_syslog(int type)
1422{
1423 int rc;
1424
1425 rc = secondary_ops->syslog(type);
1426 if (rc)
1427 return rc;
1428
1429 switch (type) {
1430 case 3: /* Read last kernel messages */
1431 case 10: /* Return size of the log buffer */
1432 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1433 break;
1434 case 6: /* Disable logging to console */
1435 case 7: /* Enable logging to console */
1436 case 8: /* Set level of messages printed to console */
1437 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1438 break;
1439 case 0: /* Close log */
1440 case 1: /* Open log */
1441 case 2: /* Read from log */
1442 case 4: /* Read/clear last kernel messages */
1443 case 5: /* Clear ring buffer */
1444 default:
1445 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1446 break;
1447 }
1448 return rc;
1449}
1450
1451/*
1452 * Check that a process has enough memory to allocate a new virtual
1453 * mapping. 0 means there is enough memory for the allocation to
1454 * succeed and -ENOMEM implies there is not.
1455 *
1456 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1457 * if the capability is granted, but __vm_enough_memory requires 1 if
1458 * the capability is granted.
1459 *
1460 * Do not audit the selinux permission check, as this is applied to all
1461 * processes that allocate mappings.
1462 */
1463static int selinux_vm_enough_memory(long pages)
1464{
1465 int rc, cap_sys_admin = 0;
1466 struct task_security_struct *tsec = current->security;
1467
1468 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1469 if (rc == 0)
1470 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1471 SECCLASS_CAPABILITY,
1472 CAP_TO_MASK(CAP_SYS_ADMIN),
1473 NULL);
1474
1475 if (rc == 0)
1476 cap_sys_admin = 1;
1477
1478 return __vm_enough_memory(pages, cap_sys_admin);
1479}
1480
1481/* binprm security operations */
1482
1483static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1484{
1485 struct bprm_security_struct *bsec;
1486
89d155ef 1487 bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1da177e4
LT		 1488 if (!bsec)
1489 return -ENOMEM;
1490
1da177e4
LT		 1491 bsec->bprm = bprm;
1492 bsec->sid = SECINITSID_UNLABELED;
1493 bsec->set = 0;
1494
1495 bprm->security = bsec;
1496 return 0;
1497}
1498
1499static int selinux_bprm_set_security(struct linux_binprm *bprm)
1500{
1501 struct task_security_struct *tsec;
1502 struct inode *inode = bprm->file->f_dentry->d_inode;
1503 struct inode_security_struct *isec;
1504 struct bprm_security_struct *bsec;
1505 u32 newsid;
1506 struct avc_audit_data ad;
1507 int rc;
1508
1509 rc = secondary_ops->bprm_set_security(bprm);
1510 if (rc)
1511 return rc;
1512
1513 bsec = bprm->security;
1514
1515 if (bsec->set)
1516 return 0;
1517
1518 tsec = current->security;
1519 isec = inode->i_security;
1520
1521 /* Default to the current task SID. */
1522 bsec->sid = tsec->sid;
1523
1524 /* Reset create SID on execve. */
1525 tsec->create_sid = 0;
1526
1527 if (tsec->exec_sid) {
1528 newsid = tsec->exec_sid;
1529 /* Reset exec SID on execve. */
1530 tsec->exec_sid = 0;
1531 } else {
1532 /* Check for a default transition on this program. */
1533 rc = security_transition_sid(tsec->sid, isec->sid,
1534 SECCLASS_PROCESS, &newsid);
1535 if (rc)
1536 return rc;
1537 }
1538
1539 AVC_AUDIT_DATA_INIT(&ad, FS);
1540 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1541 ad.u.fs.dentry = bprm->file->f_dentry;
1542
1543 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1544 newsid = tsec->sid;
1545
1546 if (tsec->sid == newsid) {
1547 rc = avc_has_perm(tsec->sid, isec->sid,
1548 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1549 if (rc)
1550 return rc;
1551 } else {
1552 /* Check permissions for the transition. */
1553 rc = avc_has_perm(tsec->sid, newsid,
1554 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1555 if (rc)
1556 return rc;
1557
1558 rc = avc_has_perm(newsid, isec->sid,
1559 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1560 if (rc)
1561 return rc;
1562
1563 /* Clear any possibly unsafe personality bits on exec: */
1564 current->personality &= ~PER_CLEAR_ON_SETID;
1565
1566 /* Set the security field to the new SID. */
1567 bsec->sid = newsid;
1568 }
1569
1570 bsec->set = 1;
1571 return 0;
1572}
1573
1574static int selinux_bprm_check_security (struct linux_binprm *bprm)
1575{
1576 return secondary_ops->bprm_check_security(bprm);
1577}
1578
1579
1580static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1581{
1582 struct task_security_struct *tsec = current->security;
1583 int atsecure = 0;
1584
1585 if (tsec->osid != tsec->sid) {
1586 /* Enable secure mode for SIDs transitions unless
1587 the noatsecure permission is granted between
1588 the two SIDs, i.e. ahp returns 0. */
1589 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1590 SECCLASS_PROCESS,
1591 PROCESS__NOATSECURE, NULL);
1592 }
1593
1594 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1595}
1596
1597static void selinux_bprm_free_security(struct linux_binprm *bprm)
1598{
9a5f04bf 1599 kfree(bprm->security);
1da177e4 1600 bprm->security = NULL;
1da177e4
LT		 1601}
1602
1603extern struct vfsmount *selinuxfs_mount;
1604extern struct dentry *selinux_null;
1605
1606/* Derived from fs/exec.c:flush_old_files. */
1607static inline void flush_unauthorized_files(struct files_struct * files)
1608{
1609 struct avc_audit_data ad;
1610 struct file *file, *devnull = NULL;
1611 struct tty_struct *tty = current->signal->tty;
badf1662 1612 struct fdtable *fdt;
1da177e4
LT		 1613 long j = -1;
1614
1615 if (tty) {
1616 file_list_lock();
2f512016 1617 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1da177e4
LT		 1618 if (file) {
1619 /* Revalidate access to controlling tty.
1620 Use inode_has_perm on the tty inode directly rather
1621 than using file_has_perm, as this particular open
1622 file may belong to another process and we are only
1623 interested in the inode-based check here. */
1624 struct inode *inode = file->f_dentry->d_inode;
1625 if (inode_has_perm(current, inode,
1626 FILE__READ | FILE__WRITE, NULL)) {
1627 /* Reset controlling tty. */
1628 current->signal->tty = NULL;
1629 current->signal->tty_old_pgrp = 0;
1630 }
1631 }
1632 file_list_unlock();
1633 }
1634
1635 /* Revalidate access to inherited open files. */
1636
1637 AVC_AUDIT_DATA_INIT(&ad,FS);
1638
1639 spin_lock(&files->file_lock);
1640 for (;;) {
1641 unsigned long set, i;
1642 int fd;
1643
1644 j++;
1645 i = j * __NFDBITS;
badf1662
DS		 1646 fdt = files_fdtable(files);
1647 if (i >= fdt->max_fds || i >= fdt->max_fdset)
1da177e4 1648 break;
badf1662 1649 set = fdt->open_fds->fds_bits[j];
1da177e4
LT		 1650 if (!set)
1651 continue;
1652 spin_unlock(&files->file_lock);
1653 for ( ; set ; i++,set >>= 1) {
1654 if (set & 1) {
1655 file = fget(i);
1656 if (!file)
1657 continue;
1658 if (file_has_perm(current,
1659 file,
1660 file_to_av(file))) {
1661 sys_close(i);
1662 fd = get_unused_fd();
1663 if (fd != i) {
1664 if (fd >= 0)
1665 put_unused_fd(fd);
1666 fput(file);
1667 continue;
1668 }
1669 if (devnull) {
095975da 1670 get_file(devnull);
1da177e4
LT		 1671 } else {
1672 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1673 if (!devnull) {
1674 put_unused_fd(fd);
1675 fput(file);
1676 continue;
1677 }
1678 }
1679 fd_install(fd, devnull);
1680 }
1681 fput(file);
1682 }
1683 }
1684 spin_lock(&files->file_lock);
1685
1686 }
1687 spin_unlock(&files->file_lock);
1688}
1689
1690static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1691{
1692 struct task_security_struct *tsec;
1693 struct bprm_security_struct *bsec;
1694 u32 sid;
1695 int rc;
1696
1697 secondary_ops->bprm_apply_creds(bprm, unsafe);
1698
1699 tsec = current->security;
1700
1701 bsec = bprm->security;
1702 sid = bsec->sid;
1703
1704 tsec->osid = tsec->sid;
1705 bsec->unsafe = 0;
1706 if (tsec->sid != sid) {
1707 /* Check for shared state. If not ok, leave SID
1708 unchanged and kill. */
1709 if (unsafe & LSM_UNSAFE_SHARE) {
1710 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1711 PROCESS__SHARE, NULL);
1712 if (rc) {
1713 bsec->unsafe = 1;
1714 return;
1715 }
1716 }
1717
1718 /* Check for ptracing, and update the task SID if ok.
1719 Otherwise, leave SID unchanged and kill. */
1720 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1721 rc = avc_has_perm(tsec->ptrace_sid, sid,
1722 SECCLASS_PROCESS, PROCESS__PTRACE,
1723 NULL);
1724 if (rc) {
1725 bsec->unsafe = 1;
1726 return;
1727 }
1728 }
1729 tsec->sid = sid;
1730 }
1731}
1732
1733/*
1734 * called after apply_creds without the task lock held
1735 */
1736static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1737{
1738 struct task_security_struct *tsec;
1739 struct rlimit *rlim, *initrlim;
1740 struct itimerval itimer;
1741 struct bprm_security_struct *bsec;
1742 int rc, i;
1743
1744 tsec = current->security;
1745 bsec = bprm->security;
1746
1747 if (bsec->unsafe) {
1748 force_sig_specific(SIGKILL, current);
1749 return;
1750 }
1751 if (tsec->osid == tsec->sid)
1752 return;
1753
1754 /* Close files for which the new task SID is not authorized. */
1755 flush_unauthorized_files(current->files);
1756
1757 /* Check whether the new SID can inherit signal state
1758 from the old SID. If not, clear itimers to avoid
1759 subsequent signal generation and flush and unblock
1760 signals. This must occur _after_ the task SID has
1761 been updated so that any kill done after the flush
1762 will be checked against the new SID. */
1763 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1764 PROCESS__SIGINH, NULL);
1765 if (rc) {
1766 memset(&itimer, 0, sizeof itimer);
1767 for (i = 0; i < 3; i++)
1768 do_setitimer(i, &itimer, NULL);
1769 flush_signals(current);
1770 spin_lock_irq(&current->sighand->siglock);
1771 flush_signal_handlers(current, 1);
1772 sigemptyset(&current->blocked);
1773 recalc_sigpending();
1774 spin_unlock_irq(&current->sighand->siglock);
1775 }
1776
1777 /* Check whether the new SID can inherit resource limits
1778 from the old SID. If not, reset all soft limits to
1779 the lower of the current task's hard limit and the init
1780 task's soft limit. Note that the setting of hard limits
1781 (even to lower them) can be controlled by the setrlimit
1782 check. The inclusion of the init task's soft limit into
1783 the computation is to avoid resetting soft limits higher
1784 than the default soft limit for cases where the default
1785 is lower than the hard limit, e.g. RLIMIT_CORE or
1786 RLIMIT_STACK.*/
1787 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1788 PROCESS__RLIMITINH, NULL);
1789 if (rc) {
1790 for (i = 0; i < RLIM_NLIMITS; i++) {
1791 rlim = current->signal->rlim + i;
1792 initrlim = init_task.signal->rlim+i;
1793 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1794 }
1795 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1796 /*
1797 * This will cause RLIMIT_CPU calculations
1798 * to be refigured.
1799 */
1800 current->it_prof_expires = jiffies_to_cputime(1);
1801 }
1802 }
1803
1804 /* Wake up the parent if it is waiting so that it can
1805 recheck wait permission to the new task SID. */
1806 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1807}
1808
1809/* superblock security operations */
1810
1811static int selinux_sb_alloc_security(struct super_block *sb)
1812{
1813 return superblock_alloc_security(sb);
1814}
1815
1816static void selinux_sb_free_security(struct super_block *sb)
1817{
1818 superblock_free_security(sb);
1819}
1820
1821static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1822{
1823 if (plen > olen)
1824 return 0;
1825
1826 return !memcmp(prefix, option, plen);
1827}
1828
1829static inline int selinux_option(char *option, int len)
1830{
1831 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1832 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1833 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len));
1834}
1835
1836static inline void take_option(char **to, char *from, int *first, int len)
1837{
1838 if (!*first) {
1839 **to = ',';
1840 *to += 1;
1841 }
1842 else
1843 *first = 0;
1844 memcpy(*to, from, len);
1845 *to += len;
1846}
1847
1848static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1849{
1850 int fnosec, fsec, rc = 0;
1851 char *in_save, *in_curr, *in_end;
1852 char *sec_curr, *nosec_save, *nosec;
1853
1854 in_curr = orig;
1855 sec_curr = copy;
1856
1857 /* Binary mount data: just copy */
1858 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1859 copy_page(sec_curr, in_curr);
1860 goto out;
1861 }
1862
1863 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1864 if (!nosec) {
1865 rc = -ENOMEM;
1866 goto out;
1867 }
1868
1869 nosec_save = nosec;
1870 fnosec = fsec = 1;
1871 in_save = in_end = orig;
1872
1873 do {
1874 if (*in_end == ',' || *in_end == '\0') {
1875 int len = in_end - in_curr;
1876
1877 if (selinux_option(in_curr, len))
1878 take_option(&sec_curr, in_curr, &fsec, len);
1879 else
1880 take_option(&nosec, in_curr, &fnosec, len);
1881
1882 in_curr = in_end + 1;
1883 }
1884 } while (*in_end++);
1885
6931dfc9 1886 strcpy(in_save, nosec_save);
da3caa20 1887 free_page((unsigned long)nosec_save);
1da177e4
LT		 1888out:
1889 return rc;
1890}
1891
1892static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1893{
1894 struct avc_audit_data ad;
1895 int rc;
1896
1897 rc = superblock_doinit(sb, data);
1898 if (rc)
1899 return rc;
1900
1901 AVC_AUDIT_DATA_INIT(&ad,FS);
1902 ad.u.fs.dentry = sb->s_root;
1903 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1904}
1905
726c3342 1906static int selinux_sb_statfs(struct dentry *dentry)
1da177e4
LT		 1907{
1908 struct avc_audit_data ad;
1909
1910 AVC_AUDIT_DATA_INIT(&ad,FS);
726c3342
DH		 1911 ad.u.fs.dentry = dentry->d_sb->s_root;
1912 return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
1da177e4
LT		 1913}
1914
1915static int selinux_mount(char * dev_name,
1916 struct nameidata *nd,
1917 char * type,
1918 unsigned long flags,
1919 void * data)
1920{
1921 int rc;
1922
1923 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
1924 if (rc)
1925 return rc;
1926
1927 if (flags & MS_REMOUNT)
1928 return superblock_has_perm(current, nd->mnt->mnt_sb,
1929 FILESYSTEM__REMOUNT, NULL);
1930 else
1931 return dentry_has_perm(current, nd->mnt, nd->dentry,
1932 FILE__MOUNTON);
1933}
1934
1935static int selinux_umount(struct vfsmount *mnt, int flags)
1936{
1937 int rc;
1938
1939 rc = secondary_ops->sb_umount(mnt, flags);
1940 if (rc)
1941 return rc;
1942
1943 return superblock_has_perm(current,mnt->mnt_sb,
1944 FILESYSTEM__UNMOUNT,NULL);
1945}
1946
1947/* inode security operations */
1948
1949static int selinux_inode_alloc_security(struct inode *inode)
1950{
1951 return inode_alloc_security(inode);
1952}
1953
1954static void selinux_inode_free_security(struct inode *inode)
1955{
1956 inode_free_security(inode);
1957}
1958
5e41ff9e
SS		 1959static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
1960 char **name, void **value,
1961 size_t *len)
1962{
1963 struct task_security_struct *tsec;
1964 struct inode_security_struct *dsec;
1965 struct superblock_security_struct *sbsec;
570bc1c2 1966 u32 newsid, clen;
5e41ff9e 1967 int rc;
570bc1c2 1968 char *namep = NULL, *context;
5e41ff9e
SS		 1969
1970 tsec = current->security;
1971 dsec = dir->i_security;
1972 sbsec = dir->i_sb->s_security;
5e41ff9e
SS		 1973
1974 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1975 newsid = tsec->create_sid;
1976 } else {
1977 rc = security_transition_sid(tsec->sid, dsec->sid,
1978 inode_mode_to_security_class(inode->i_mode),
1979 &newsid);
1980 if (rc) {
1981 printk(KERN_WARNING "%s: "
1982 "security_transition_sid failed, rc=%d (dev=%s "
1983 "ino=%ld)\n",
1984 __FUNCTION__,
1985 -rc, inode->i_sb->s_id, inode->i_ino);
1986 return rc;
1987 }
1988 }
1989
1990 inode_security_set_sid(inode, newsid);
1991
8aad3875 1992 if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
25a74f3b
SS		 1993 return -EOPNOTSUPP;
1994
570bc1c2
SS		 1995 if (name) {
1996 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
1997 if (!namep)
1998 return -ENOMEM;
1999 *name = namep;
2000 }
5e41ff9e 2001
570bc1c2
SS		 2002 if (value && len) {
2003 rc = security_sid_to_context(newsid, &context, &clen);
2004 if (rc) {
2005 kfree(namep);
2006 return rc;
2007 }
2008 *value = context;
2009 *len = clen;
5e41ff9e 2010 }
5e41ff9e 2011
5e41ff9e
SS		 2012 return 0;
2013}
2014
1da177e4
LT		 2015static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2016{
2017 return may_create(dir, dentry, SECCLASS_FILE);
2018}
2019
1da177e4
LT		 2020static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2021{
2022 int rc;
2023
2024 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2025 if (rc)
2026 return rc;
2027 return may_link(dir, old_dentry, MAY_LINK);
2028}
2029
1da177e4
LT		 2030static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2031{
2032 int rc;
2033
2034 rc = secondary_ops->inode_unlink(dir, dentry);
2035 if (rc)
2036 return rc;
2037 return may_link(dir, dentry, MAY_UNLINK);
2038}
2039
2040static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2041{
2042 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2043}
2044
1da177e4
LT		 2045static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2046{
2047 return may_create(dir, dentry, SECCLASS_DIR);
2048}
2049
1da177e4
LT		 2050static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2051{
2052 return may_link(dir, dentry, MAY_RMDIR);
2053}
2054
2055static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2056{
2057 int rc;
2058
2059 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2060 if (rc)
2061 return rc;
2062
2063 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2064}
2065
1da177e4
LT		 2066static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2067 struct inode *new_inode, struct dentry *new_dentry)
2068{
2069 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2070}
2071
1da177e4
LT		 2072static int selinux_inode_readlink(struct dentry *dentry)
2073{
2074 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2075}
2076
2077static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2078{
2079 int rc;
2080
2081 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2082 if (rc)
2083 return rc;
2084 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2085}
2086
2087static int selinux_inode_permission(struct inode *inode, int mask,
2088 struct nameidata *nd)
2089{
2090 int rc;
2091
2092 rc = secondary_ops->inode_permission(inode, mask, nd);
2093 if (rc)
2094 return rc;
2095
2096 if (!mask) {
2097 /* No permission to check. Existence test. */
2098 return 0;
2099 }
2100
2101 return inode_has_perm(current, inode,
2102 file_mask_to_av(inode->i_mode, mask), NULL);
2103}
2104
2105static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2106{
2107 int rc;
2108
2109 rc = secondary_ops->inode_setattr(dentry, iattr);
2110 if (rc)
2111 return rc;
2112
2113 if (iattr->ia_valid & ATTR_FORCE)
2114 return 0;
2115
2116 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2117 ATTR_ATIME_SET | ATTR_MTIME_SET))
2118 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2119
2120 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2121}
2122
2123static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2124{
2125 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2126}
2127
2128static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2129{
2130 struct task_security_struct *tsec = current->security;
2131 struct inode *inode = dentry->d_inode;
2132 struct inode_security_struct *isec = inode->i_security;
2133 struct superblock_security_struct *sbsec;
2134 struct avc_audit_data ad;
2135 u32 newsid;
2136 int rc = 0;
2137
2138 if (strcmp(name, XATTR_NAME_SELINUX)) {
2139 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2140 sizeof XATTR_SECURITY_PREFIX - 1) &&
2141 !capable(CAP_SYS_ADMIN)) {
2142 /* A different attribute in the security namespace.
2143 Restrict to administrator. */
2144 return -EPERM;
2145 }
2146
2147 /* Not an attribute we recognize, so just check the
2148 ordinary setattr permission. */
2149 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2150 }
2151
2152 sbsec = inode->i_sb->s_security;
2153 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2154 return -EOPNOTSUPP;
2155
2156 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2157 return -EPERM;
2158
2159 AVC_AUDIT_DATA_INIT(&ad,FS);
2160 ad.u.fs.dentry = dentry;
2161
2162 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2163 FILE__RELABELFROM, &ad);
2164 if (rc)
2165 return rc;
2166
2167 rc = security_context_to_sid(value, size, &newsid);
2168 if (rc)
2169 return rc;
2170
2171 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2172 FILE__RELABELTO, &ad);
2173 if (rc)
2174 return rc;
2175
2176 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2177 isec->sclass);
2178 if (rc)
2179 return rc;
2180
2181 return avc_has_perm(newsid,
2182 sbsec->sid,
2183 SECCLASS_FILESYSTEM,
2184 FILESYSTEM__ASSOCIATE,
2185 &ad);
2186}
2187
2188static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2189 void *value, size_t size, int flags)
2190{
2191 struct inode *inode = dentry->d_inode;
2192 struct inode_security_struct *isec = inode->i_security;
2193 u32 newsid;
2194 int rc;
2195
2196 if (strcmp(name, XATTR_NAME_SELINUX)) {
2197 /* Not an attribute we recognize, so nothing to do. */
2198 return;
2199 }
2200
2201 rc = security_context_to_sid(value, size, &newsid);
2202 if (rc) {
2203 printk(KERN_WARNING "%s: unable to obtain SID for context "
2204 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2205 return;
2206 }
2207
2208 isec->sid = newsid;
2209 return;
2210}
2211
2212static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2213{
1da177e4
LT		 2214 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2215}
2216
2217static int selinux_inode_listxattr (struct dentry *dentry)
2218{
2219 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2220}
2221
2222static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2223{
2224 if (strcmp(name, XATTR_NAME_SELINUX)) {
2225 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2226 sizeof XATTR_SECURITY_PREFIX - 1) &&
2227 !capable(CAP_SYS_ADMIN)) {
2228 /* A different attribute in the security namespace.
2229 Restrict to administrator. */
2230 return -EPERM;
2231 }
2232
2233 /* Not an attribute we recognize, so just check the
2234 ordinary setattr permission. Might want a separate
2235 permission for removexattr. */
2236 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2237 }
2238
2239 /* No one is allowed to remove a SELinux security label.
2240 You can change the label, but all data must be labeled. */
2241 return -EACCES;
2242}
2243
8c8570fb
DK		 2244static const char *selinux_inode_xattr_getsuffix(void)
2245{
2246 return XATTR_SELINUX_SUFFIX;
2247}
2248
d381d8a9
JM		 2249/*
2250 * Copy the in-core inode security context value to the user. If the
2251 * getxattr() prior to this succeeded, check to see if we need to
2252 * canonicalize the value to be finally returned to the user.
2253 *
2254 * Permission check is handled by selinux_inode_getxattr hook.
2255 */
7306a0b9 2256static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err)
1da177e4
LT		 2257{
2258 struct inode_security_struct *isec = inode->i_security;
d381d8a9 2259
8c8570fb
DK		 2260 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2261 return -EOPNOTSUPP;
d381d8a9 2262
8c8570fb 2263 return selinux_getsecurity(isec->sid, buffer, size);
1da177e4
LT		 2264}
2265
2266static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2267 const void *value, size_t size, int flags)
2268{
2269 struct inode_security_struct *isec = inode->i_security;
2270 u32 newsid;
2271 int rc;
2272
2273 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2274 return -EOPNOTSUPP;
2275
2276 if (!value || !size)
2277 return -EACCES;
2278
2279 rc = security_context_to_sid((void*)value, size, &newsid);
2280 if (rc)
2281 return rc;
2282
2283 isec->sid = newsid;
2284 return 0;
2285}
2286
2287static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2288{
2289 const int len = sizeof(XATTR_NAME_SELINUX);
2290 if (buffer && len <= buffer_size)
2291 memcpy(buffer, XATTR_NAME_SELINUX, len);
2292 return len;
2293}
2294
2295/* file security operations */
2296
2297static int selinux_file_permission(struct file *file, int mask)
2298{
2299 struct inode *inode = file->f_dentry->d_inode;
2300
2301 if (!mask) {
2302 /* No permission to check. Existence test. */
2303 return 0;
2304 }
2305
2306 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2307 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2308 mask |= MAY_APPEND;
2309
2310 return file_has_perm(current, file,
2311 file_mask_to_av(inode->i_mode, mask));
2312}
2313
2314static int selinux_file_alloc_security(struct file *file)
2315{
2316 return file_alloc_security(file);
2317}
2318
2319static void selinux_file_free_security(struct file *file)
2320{
2321 file_free_security(file);
2322}
2323
2324static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2325 unsigned long arg)
2326{
2327 int error = 0;
2328
2329 switch (cmd) {
2330 case FIONREAD:
2331 /* fall through */
2332 case FIBMAP:
2333 /* fall through */
2334 case FIGETBSZ:
2335 /* fall through */
2336 case EXT2_IOC_GETFLAGS:
2337 /* fall through */
2338 case EXT2_IOC_GETVERSION:
2339 error = file_has_perm(current, file, FILE__GETATTR);
2340 break;
2341
2342 case EXT2_IOC_SETFLAGS:
2343 /* fall through */
2344 case EXT2_IOC_SETVERSION:
2345 error = file_has_perm(current, file, FILE__SETATTR);
2346 break;
2347
2348 /* sys_ioctl() checks */
2349 case FIONBIO:
2350 /* fall through */
2351 case FIOASYNC:
2352 error = file_has_perm(current, file, 0);
2353 break;
2354
2355 case KDSKBENT:
2356 case KDSKBSENT:
2357 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2358 break;
2359
2360 /* default case assumes that the command will go
2361 * to the file's ioctl() function.
2362 */
2363 default:
2364 error = file_has_perm(current, file, FILE__IOCTL);
2365
2366 }
2367 return error;
2368}
2369
2370static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2371{
2372#ifndef CONFIG_PPC32
2373 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2374 /*
2375 * We are making executable an anonymous mapping or a
2376 * private file mapping that will also be writable.
2377 * This has an additional check.
2378 */
2379 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2380 if (rc)
2381 return rc;
2382 }
2383#endif
2384
2385 if (file) {
2386 /* read access is always possible with a mapping */
2387 u32 av = FILE__READ;
2388
2389 /* write access only matters if the mapping is shared */
2390 if (shared && (prot & PROT_WRITE))
2391 av |= FILE__WRITE;
2392
2393 if (prot & PROT_EXEC)
2394 av |= FILE__EXECUTE;
2395
2396 return file_has_perm(current, file, av);
2397 }
2398 return 0;
2399}
2400
2401static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2402 unsigned long prot, unsigned long flags)
2403{
2404 int rc;
2405
2406 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2407 if (rc)
2408 return rc;
2409
2410 if (selinux_checkreqprot)
2411 prot = reqprot;
2412
2413 return file_map_prot_check(file, prot,
2414 (flags & MAP_TYPE) == MAP_SHARED);
2415}
2416
2417static int selinux_file_mprotect(struct vm_area_struct *vma,
2418 unsigned long reqprot,
2419 unsigned long prot)
2420{
2421 int rc;
2422
2423 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2424 if (rc)
2425 return rc;
2426
2427 if (selinux_checkreqprot)
2428 prot = reqprot;
2429
2430#ifndef CONFIG_PPC32
db4c9641
SS		 2431 if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
2432 rc = 0;
2433 if (vma->vm_start >= vma->vm_mm->start_brk &&
2434 vma->vm_end <= vma->vm_mm->brk) {
2435 rc = task_has_perm(current, current,
2436 PROCESS__EXECHEAP);
2437 } else if (!vma->vm_file &&
2438 vma->vm_start <= vma->vm_mm->start_stack &&
2439 vma->vm_end >= vma->vm_mm->start_stack) {
2440 rc = task_has_perm(current, current, PROCESS__EXECSTACK);
2441 } else if (vma->vm_file && vma->anon_vma) {
2442 /*
2443 * We are making executable a file mapping that has
2444 * had some COW done. Since pages might have been
2445 * written, check ability to execute the possibly
2446 * modified content. This typically should only
2447 * occur for text relocations.
2448 */
2449 rc = file_has_perm(current, vma->vm_file,
2450 FILE__EXECMOD);
2451 }