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