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[LSM-IPSec]: Security association restriction.
[linux.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, <[email protected]>
7 * Chris Vance, <[email protected]>
8 * Wayne Salamon, <[email protected]>
9 * James Morris <[email protected]>
10 *
11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12 * Copyright (C) 2003 Red Hat, Inc., James Morris <[email protected]>
13 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
14 * <[email protected]>
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
89d155ef 125 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
1da177e4
LT		 126 if (!tsec)
127 return -ENOMEM;
128
1da177e4
LT		 129 tsec->magic = SELINUX_MAGIC;
130 tsec->task = task;
131 tsec->osid = tsec->sid = tsec->ptrace_sid = SECINITSID_UNLABELED;
132 task->security = tsec;
133
134 return 0;
135}
136
137static void task_free_security(struct task_struct *task)
138{
139 struct task_security_struct *tsec = task->security;
140
141 if (!tsec || tsec->magic != SELINUX_MAGIC)
142 return;
143
144 task->security = NULL;
145 kfree(tsec);
146}
147
148static int inode_alloc_security(struct inode *inode)
149{
150 struct task_security_struct *tsec = current->security;
151 struct inode_security_struct *isec;
152
89d155ef 153 isec = kzalloc(sizeof(struct inode_security_struct), GFP_KERNEL);
1da177e4
LT		 154 if (!isec)
155 return -ENOMEM;
156
1da177e4
LT		 157 init_MUTEX(&isec->sem);
158 INIT_LIST_HEAD(&isec->list);
159 isec->magic = SELINUX_MAGIC;
160 isec->inode = inode;
161 isec->sid = SECINITSID_UNLABELED;
162 isec->sclass = SECCLASS_FILE;
163 if (tsec && tsec->magic == SELINUX_MAGIC)
164 isec->task_sid = tsec->sid;
165 else
166 isec->task_sid = SECINITSID_UNLABELED;
167 inode->i_security = isec;
168
169 return 0;
170}
171
172static void inode_free_security(struct inode *inode)
173{
174 struct inode_security_struct *isec = inode->i_security;
175 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
176
177 if (!isec || isec->magic != SELINUX_MAGIC)
178 return;
179
180 spin_lock(&sbsec->isec_lock);
181 if (!list_empty(&isec->list))
182 list_del_init(&isec->list);
183 spin_unlock(&sbsec->isec_lock);
184
185 inode->i_security = NULL;
186 kfree(isec);
187}
188
189static int file_alloc_security(struct file *file)
190{
191 struct task_security_struct *tsec = current->security;
192 struct file_security_struct *fsec;
193
89d155ef 194 fsec = kzalloc(sizeof(struct file_security_struct), GFP_ATOMIC);
1da177e4
LT		 195 if (!fsec)
196 return -ENOMEM;
197
1da177e4
LT		 198 fsec->magic = SELINUX_MAGIC;
199 fsec->file = file;
200 if (tsec && tsec->magic == SELINUX_MAGIC) {
201 fsec->sid = tsec->sid;
202 fsec->fown_sid = tsec->sid;
203 } else {
204 fsec->sid = SECINITSID_UNLABELED;
205 fsec->fown_sid = SECINITSID_UNLABELED;
206 }
207 file->f_security = fsec;
208
209 return 0;
210}
211
212static void file_free_security(struct file *file)
213{
214 struct file_security_struct *fsec = file->f_security;
215
216 if (!fsec || fsec->magic != SELINUX_MAGIC)
217 return;
218
219 file->f_security = NULL;
220 kfree(fsec);
221}
222
223static int superblock_alloc_security(struct super_block *sb)
224{
225 struct superblock_security_struct *sbsec;
226
89d155ef 227 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
1da177e4
LT		 228 if (!sbsec)
229 return -ENOMEM;
230
1da177e4
LT		 231 init_MUTEX(&sbsec->sem);
232 INIT_LIST_HEAD(&sbsec->list);
233 INIT_LIST_HEAD(&sbsec->isec_head);
234 spin_lock_init(&sbsec->isec_lock);
235 sbsec->magic = SELINUX_MAGIC;
236 sbsec->sb = sb;
237 sbsec->sid = SECINITSID_UNLABELED;
238 sbsec->def_sid = SECINITSID_FILE;
239 sb->s_security = sbsec;
240
241 return 0;
242}
243
244static void superblock_free_security(struct super_block *sb)
245{
246 struct superblock_security_struct *sbsec = sb->s_security;
247
248 if (!sbsec || sbsec->magic != SELINUX_MAGIC)
249 return;
250
251 spin_lock(&sb_security_lock);
252 if (!list_empty(&sbsec->list))
253 list_del_init(&sbsec->list);
254 spin_unlock(&sb_security_lock);
255
256 sb->s_security = NULL;
257 kfree(sbsec);
258}
259
260#ifdef CONFIG_SECURITY_NETWORK
7d877f3b 261static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
1da177e4
LT		 262{
263 struct sk_security_struct *ssec;
264
265 if (family != PF_UNIX)
266 return 0;
267
89d155ef 268 ssec = kzalloc(sizeof(*ssec), priority);
1da177e4
LT		 269 if (!ssec)
270 return -ENOMEM;
271
1da177e4
LT		 272 ssec->magic = SELINUX_MAGIC;
273 ssec->sk = sk;
274 ssec->peer_sid = SECINITSID_UNLABELED;
275 sk->sk_security = ssec;
276
277 return 0;
278}
279
280static void sk_free_security(struct sock *sk)
281{
282 struct sk_security_struct *ssec = sk->sk_security;
283
284 if (sk->sk_family != PF_UNIX || ssec->magic != SELINUX_MAGIC)
285 return;
286
287 sk->sk_security = NULL;
288 kfree(ssec);
289}
290#endif /* CONFIG_SECURITY_NETWORK */
291
292/* The security server must be initialized before
293 any labeling or access decisions can be provided. */
294extern int ss_initialized;
295
296/* The file system's label must be initialized prior to use. */
297
298static char *labeling_behaviors[6] = {
299 "uses xattr",
300 "uses transition SIDs",
301 "uses task SIDs",
302 "uses genfs_contexts",
303 "not configured for labeling",
304 "uses mountpoint labeling",
305};
306
307static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
308
309static inline int inode_doinit(struct inode *inode)
310{
311 return inode_doinit_with_dentry(inode, NULL);
312}
313
314enum {
315 Opt_context = 1,
316 Opt_fscontext = 2,
317 Opt_defcontext = 4,
318};
319
320static match_table_t tokens = {
321 {Opt_context, "context=%s"},
322 {Opt_fscontext, "fscontext=%s"},
323 {Opt_defcontext, "defcontext=%s"},
324};
325
326#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n"
327
328static int try_context_mount(struct super_block *sb, void *data)
329{
330 char *context = NULL, *defcontext = NULL;
331 const char *name;
332 u32 sid;
333 int alloc = 0, rc = 0, seen = 0;
334 struct task_security_struct *tsec = current->security;
335 struct superblock_security_struct *sbsec = sb->s_security;
336
337 if (!data)
338 goto out;
339
340 name = sb->s_type->name;
341
342 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) {
343
344 /* NFS we understand. */
345 if (!strcmp(name, "nfs")) {
346 struct nfs_mount_data *d = data;
347
348 if (d->version < NFS_MOUNT_VERSION)
349 goto out;
350
351 if (d->context[0]) {
352 context = d->context;
353 seen |= Opt_context;
354 }
355 } else
356 goto out;
357
358 } else {
359 /* Standard string-based options. */
360 char *p, *options = data;
361
362 while ((p = strsep(&options, ",")) != NULL) {
363 int token;
364 substring_t args[MAX_OPT_ARGS];
365
366 if (!*p)
367 continue;
368
369 token = match_token(p, tokens, args);
370
371 switch (token) {
372 case Opt_context:
373 if (seen) {
374 rc = -EINVAL;
375 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
376 goto out_free;
377 }
378 context = match_strdup(&args[0]);
379 if (!context) {
380 rc = -ENOMEM;
381 goto out_free;
382 }
383 if (!alloc)
384 alloc = 1;
385 seen |= Opt_context;
386 break;
387
388 case Opt_fscontext:
389 if (seen & (Opt_context|Opt_fscontext)) {
390 rc = -EINVAL;
391 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
392 goto out_free;
393 }
394 context = match_strdup(&args[0]);
395 if (!context) {
396 rc = -ENOMEM;
397 goto out_free;
398 }
399 if (!alloc)
400 alloc = 1;
401 seen |= Opt_fscontext;
402 break;
403
404 case Opt_defcontext:
405 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
406 rc = -EINVAL;
407 printk(KERN_WARNING "SELinux: "
408 "defcontext option is invalid "
409 "for this filesystem type\n");
410 goto out_free;
411 }
412 if (seen & (Opt_context|Opt_defcontext)) {
413 rc = -EINVAL;
414 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
415 goto out_free;
416 }
417 defcontext = match_strdup(&args[0]);
418 if (!defcontext) {
419 rc = -ENOMEM;
420 goto out_free;
421 }
422 if (!alloc)
423 alloc = 1;
424 seen |= Opt_defcontext;
425 break;
426
427 default:
428 rc = -EINVAL;
429 printk(KERN_WARNING "SELinux: unknown mount "
430 "option\n");
431 goto out_free;
432
433 }
434 }
435 }
436
437 if (!seen)
438 goto out;
439
440 if (context) {
441 rc = security_context_to_sid(context, strlen(context), &sid);
442 if (rc) {
443 printk(KERN_WARNING "SELinux: security_context_to_sid"
444 "(%s) failed for (dev %s, type %s) errno=%d\n",
445 context, sb->s_id, name, rc);
446 goto out_free;
447 }
448
449 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
450 FILESYSTEM__RELABELFROM, NULL);
451 if (rc)
452 goto out_free;
453
454 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
455 FILESYSTEM__RELABELTO, NULL);
456 if (rc)
457 goto out_free;
458
459 sbsec->sid = sid;
460
461 if (seen & Opt_context)
462 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
463 }
464
465 if (defcontext) {
466 rc = security_context_to_sid(defcontext, strlen(defcontext), &sid);
467 if (rc) {
468 printk(KERN_WARNING "SELinux: security_context_to_sid"
469 "(%s) failed for (dev %s, type %s) errno=%d\n",
470 defcontext, sb->s_id, name, rc);
471 goto out_free;
472 }
473
474 if (sid == sbsec->def_sid)
475 goto out_free;
476
477 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
478 FILESYSTEM__RELABELFROM, NULL);
479 if (rc)
480 goto out_free;
481
482 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
483 FILESYSTEM__ASSOCIATE, NULL);
484 if (rc)
485 goto out_free;
486
487 sbsec->def_sid = sid;
488 }
489
490out_free:
491 if (alloc) {
492 kfree(context);
493 kfree(defcontext);
494 }
495out:
496 return rc;
497}
498
499static int superblock_doinit(struct super_block *sb, void *data)
500{
501 struct superblock_security_struct *sbsec = sb->s_security;
502 struct dentry *root = sb->s_root;
503 struct inode *inode = root->d_inode;
504 int rc = 0;
505
506 down(&sbsec->sem);
507 if (sbsec->initialized)
508 goto out;
509
510 if (!ss_initialized) {
511 /* Defer initialization until selinux_complete_init,
512 after the initial policy is loaded and the security
513 server is ready to handle calls. */
514 spin_lock(&sb_security_lock);
515 if (list_empty(&sbsec->list))
516 list_add(&sbsec->list, &superblock_security_head);
517 spin_unlock(&sb_security_lock);
518 goto out;
519 }
520
521 /* Determine the labeling behavior to use for this filesystem type. */
522 rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
523 if (rc) {
524 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
525 __FUNCTION__, sb->s_type->name, rc);
526 goto out;
527 }
528
529 rc = try_context_mount(sb, data);
530 if (rc)
531 goto out;
532
533 if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
534 /* Make sure that the xattr handler exists and that no
535 error other than -ENODATA is returned by getxattr on
536 the root directory. -ENODATA is ok, as this may be
537 the first boot of the SELinux kernel before we have
538 assigned xattr values to the filesystem. */
539 if (!inode->i_op->getxattr) {
540 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
541 "xattr support\n", sb->s_id, sb->s_type->name);
542 rc = -EOPNOTSUPP;
543 goto out;
544 }
545 rc = inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
546 if (rc < 0 && rc != -ENODATA) {
547 if (rc == -EOPNOTSUPP)
548 printk(KERN_WARNING "SELinux: (dev %s, type "
549 "%s) has no security xattr handler\n",
550 sb->s_id, sb->s_type->name);
551 else
552 printk(KERN_WARNING "SELinux: (dev %s, type "
553 "%s) getxattr errno %d\n", sb->s_id,
554 sb->s_type->name, -rc);
555 goto out;
556 }
557 }
558
559 if (strcmp(sb->s_type->name, "proc") == 0)
560 sbsec->proc = 1;
561
562 sbsec->initialized = 1;
563
564 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) {
565 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), unknown behavior\n",
566 sb->s_id, sb->s_type->name);
567 }
568 else {
569 printk(KERN_INFO "SELinux: initialized (dev %s, type %s), %s\n",
570 sb->s_id, sb->s_type->name,
571 labeling_behaviors[sbsec->behavior-1]);
572 }
573
574 /* Initialize the root inode. */
575 rc = inode_doinit_with_dentry(sb->s_root->d_inode, sb->s_root);
576
577 /* Initialize any other inodes associated with the superblock, e.g.
578 inodes created prior to initial policy load or inodes created
579 during get_sb by a pseudo filesystem that directly
580 populates itself. */
581 spin_lock(&sbsec->isec_lock);
582next_inode:
583 if (!list_empty(&sbsec->isec_head)) {
584 struct inode_security_struct *isec =
585 list_entry(sbsec->isec_head.next,
586 struct inode_security_struct, list);
587 struct inode *inode = isec->inode;
588 spin_unlock(&sbsec->isec_lock);
589 inode = igrab(inode);
590 if (inode) {
591 if (!IS_PRIVATE (inode))
592 inode_doinit(inode);
593 iput(inode);
594 }
595 spin_lock(&sbsec->isec_lock);
596 list_del_init(&isec->list);
597 goto next_inode;
598 }
599 spin_unlock(&sbsec->isec_lock);
600out:
601 up(&sbsec->sem);
602 return rc;
603}
604
605static inline u16 inode_mode_to_security_class(umode_t mode)
606{
607 switch (mode & S_IFMT) {
608 case S_IFSOCK:
609 return SECCLASS_SOCK_FILE;
610 case S_IFLNK:
611 return SECCLASS_LNK_FILE;
612 case S_IFREG:
613 return SECCLASS_FILE;
614 case S_IFBLK:
615 return SECCLASS_BLK_FILE;
616 case S_IFDIR:
617 return SECCLASS_DIR;
618 case S_IFCHR:
619 return SECCLASS_CHR_FILE;
620 case S_IFIFO:
621 return SECCLASS_FIFO_FILE;
622
623 }
624
625 return SECCLASS_FILE;
626}
627
13402580
JM		 628static inline int default_protocol_stream(int protocol)
629{
630 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
631}
632
633static inline int default_protocol_dgram(int protocol)
634{
635 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
636}
637
1da177e4
LT		 638static inline u16 socket_type_to_security_class(int family, int type, int protocol)
639{
640 switch (family) {
641 case PF_UNIX:
642 switch (type) {
643 case SOCK_STREAM:
644 case SOCK_SEQPACKET:
645 return SECCLASS_UNIX_STREAM_SOCKET;
646 case SOCK_DGRAM:
647 return SECCLASS_UNIX_DGRAM_SOCKET;
648 }
649 break;
650 case PF_INET:
651 case PF_INET6:
652 switch (type) {
653 case SOCK_STREAM:
13402580
JM		 654 if (default_protocol_stream(protocol))
655 return SECCLASS_TCP_SOCKET;
656 else
657 return SECCLASS_RAWIP_SOCKET;
1da177e4 658 case SOCK_DGRAM:
13402580
JM		 659 if (default_protocol_dgram(protocol))
660 return SECCLASS_UDP_SOCKET;
661 else
662 return SECCLASS_RAWIP_SOCKET;
663 default:
1da177e4
LT		 664 return SECCLASS_RAWIP_SOCKET;
665 }
666 break;
667 case PF_NETLINK:
668 switch (protocol) {
669 case NETLINK_ROUTE:
670 return SECCLASS_NETLINK_ROUTE_SOCKET;
671 case NETLINK_FIREWALL:
672 return SECCLASS_NETLINK_FIREWALL_SOCKET;
216efaaa 673 case NETLINK_INET_DIAG:
1da177e4
LT		 674 return SECCLASS_NETLINK_TCPDIAG_SOCKET;
675 case NETLINK_NFLOG:
676 return SECCLASS_NETLINK_NFLOG_SOCKET;
677 case NETLINK_XFRM:
678 return SECCLASS_NETLINK_XFRM_SOCKET;
679 case NETLINK_SELINUX:
680 return SECCLASS_NETLINK_SELINUX_SOCKET;
681 case NETLINK_AUDIT:
682 return SECCLASS_NETLINK_AUDIT_SOCKET;
683 case NETLINK_IP6_FW:
684 return SECCLASS_NETLINK_IP6FW_SOCKET;
685 case NETLINK_DNRTMSG:
686 return SECCLASS_NETLINK_DNRT_SOCKET;
0c9b7942
JM		 687 case NETLINK_KOBJECT_UEVENT:
688 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1da177e4
LT		 689 default:
690 return SECCLASS_NETLINK_SOCKET;
691 }
692 case PF_PACKET:
693 return SECCLASS_PACKET_SOCKET;
694 case PF_KEY:
695 return SECCLASS_KEY_SOCKET;
696 }
697
698 return SECCLASS_SOCKET;
699}
700
701#ifdef CONFIG_PROC_FS
702static int selinux_proc_get_sid(struct proc_dir_entry *de,
703 u16 tclass,
704 u32 *sid)
705{
706 int buflen, rc;
707 char *buffer, *path, *end;
708
709 buffer = (char*)__get_free_page(GFP_KERNEL);
710 if (!buffer)
711 return -ENOMEM;
712
713 buflen = PAGE_SIZE;
714 end = buffer+buflen;
715 *--end = '\0';
716 buflen--;
717 path = end-1;
718 *path = '/';
719 while (de && de != de->parent) {
720 buflen -= de->namelen + 1;
721 if (buflen < 0)
722 break;
723 end -= de->namelen;
724 memcpy(end, de->name, de->namelen);
725 *--end = '/';
726 path = end;
727 de = de->parent;
728 }
729 rc = security_genfs_sid("proc", path, tclass, sid);
730 free_page((unsigned long)buffer);
731 return rc;
732}
733#else
734static int selinux_proc_get_sid(struct proc_dir_entry *de,
735 u16 tclass,
736 u32 *sid)
737{
738 return -EINVAL;
739}
740#endif
741
742/* The inode's security attributes must be initialized before first use. */
743static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
744{
745 struct superblock_security_struct *sbsec = NULL;
746 struct inode_security_struct *isec = inode->i_security;
747 u32 sid;
748 struct dentry *dentry;
749#define INITCONTEXTLEN 255
750 char *context = NULL;
751 unsigned len = 0;
752 int rc = 0;
753 int hold_sem = 0;
754
755 if (isec->initialized)
756 goto out;
757
758 down(&isec->sem);
759 hold_sem = 1;
760 if (isec->initialized)
761 goto out;
762
763 sbsec = inode->i_sb->s_security;
764 if (!sbsec->initialized) {
765 /* Defer initialization until selinux_complete_init,
766 after the initial policy is loaded and the security
767 server is ready to handle calls. */
768 spin_lock(&sbsec->isec_lock);
769 if (list_empty(&isec->list))
770 list_add(&isec->list, &sbsec->isec_head);
771 spin_unlock(&sbsec->isec_lock);
772 goto out;
773 }
774
775 switch (sbsec->behavior) {
776 case SECURITY_FS_USE_XATTR:
777 if (!inode->i_op->getxattr) {
778 isec->sid = sbsec->def_sid;
779 break;
780 }
781
782 /* Need a dentry, since the xattr API requires one.
783 Life would be simpler if we could just pass the inode. */
784 if (opt_dentry) {
785 /* Called from d_instantiate or d_splice_alias. */
786 dentry = dget(opt_dentry);
787 } else {
788 /* Called from selinux_complete_init, try to find a dentry. */
789 dentry = d_find_alias(inode);
790 }
791 if (!dentry) {
792 printk(KERN_WARNING "%s: no dentry for dev=%s "
793 "ino=%ld\n", __FUNCTION__, inode->i_sb->s_id,
794 inode->i_ino);
795 goto out;
796 }
797
798 len = INITCONTEXTLEN;
799 context = kmalloc(len, GFP_KERNEL);
800 if (!context) {
801 rc = -ENOMEM;
802 dput(dentry);
803 goto out;
804 }
805 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
806 context, len);
807 if (rc == -ERANGE) {
808 /* Need a larger buffer. Query for the right size. */
809 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
810 NULL, 0);
811 if (rc < 0) {
812 dput(dentry);
813 goto out;
814 }
815 kfree(context);
816 len = rc;
817 context = kmalloc(len, GFP_KERNEL);
818 if (!context) {
819 rc = -ENOMEM;
820 dput(dentry);
821 goto out;
822 }
823 rc = inode->i_op->getxattr(dentry,
824 XATTR_NAME_SELINUX,
825 context, len);
826 }
827 dput(dentry);
828 if (rc < 0) {
829 if (rc != -ENODATA) {
830 printk(KERN_WARNING "%s: getxattr returned "
831 "%d for dev=%s ino=%ld\n", __FUNCTION__,
832 -rc, inode->i_sb->s_id, inode->i_ino);
833 kfree(context);
834 goto out;
835 }
836 /* Map ENODATA to the default file SID */
837 sid = sbsec->def_sid;
838 rc = 0;
839 } else {
f5c1d5b2
JM		 840 rc = security_context_to_sid_default(context, rc, &sid,
841 sbsec->def_sid);
1da177e4
LT		 842 if (rc) {
843 printk(KERN_WARNING "%s: context_to_sid(%s) "
844 "returned %d for dev=%s ino=%ld\n",
845 __FUNCTION__, context, -rc,
846 inode->i_sb->s_id, inode->i_ino);
847 kfree(context);
848 /* Leave with the unlabeled SID */
849 rc = 0;
850 break;
851 }
852 }
853 kfree(context);
854 isec->sid = sid;
855 break;
856 case SECURITY_FS_USE_TASK:
857 isec->sid = isec->task_sid;
858 break;
859 case SECURITY_FS_USE_TRANS:
860 /* Default to the fs SID. */
861 isec->sid = sbsec->sid;
862
863 /* Try to obtain a transition SID. */
864 isec->sclass = inode_mode_to_security_class(inode->i_mode);
865 rc = security_transition_sid(isec->task_sid,
866 sbsec->sid,
867 isec->sclass,
868 &sid);
869 if (rc)
870 goto out;
871 isec->sid = sid;
872 break;
873 default:
874 /* Default to the fs SID. */
875 isec->sid = sbsec->sid;
876
877 if (sbsec->proc) {
878 struct proc_inode *proci = PROC_I(inode);
879 if (proci->pde) {
880 isec->sclass = inode_mode_to_security_class(inode->i_mode);
881 rc = selinux_proc_get_sid(proci->pde,
882 isec->sclass,
883 &sid);
884 if (rc)
885 goto out;
886 isec->sid = sid;
887 }
888 }
889 break;
890 }
891
892 isec->initialized = 1;
893
894out:
895 if (isec->sclass == SECCLASS_FILE)
896 isec->sclass = inode_mode_to_security_class(inode->i_mode);
897
898 if (hold_sem)
899 up(&isec->sem);
900 return rc;
901}
902
903/* Convert a Linux signal to an access vector. */
904static inline u32 signal_to_av(int sig)
905{
906 u32 perm = 0;
907
908 switch (sig) {
909 case SIGCHLD:
910 /* Commonly granted from child to parent. */
911 perm = PROCESS__SIGCHLD;
912 break;
913 case SIGKILL:
914 /* Cannot be caught or ignored */
915 perm = PROCESS__SIGKILL;
916 break;
917 case SIGSTOP:
918 /* Cannot be caught or ignored */
919 perm = PROCESS__SIGSTOP;
920 break;
921 default:
922 /* All other signals. */
923 perm = PROCESS__SIGNAL;
924 break;
925 }
926
927 return perm;
928}
929
930/* Check permission betweeen a pair of tasks, e.g. signal checks,
931 fork check, ptrace check, etc. */
932static int task_has_perm(struct task_struct *tsk1,
933 struct task_struct *tsk2,
934 u32 perms)
935{
936 struct task_security_struct *tsec1, *tsec2;
937
938 tsec1 = tsk1->security;
939 tsec2 = tsk2->security;
940 return avc_has_perm(tsec1->sid, tsec2->sid,
941 SECCLASS_PROCESS, perms, NULL);
942}
943
944/* Check whether a task is allowed to use a capability. */
945static int task_has_capability(struct task_struct *tsk,
946 int cap)
947{
948 struct task_security_struct *tsec;
949 struct avc_audit_data ad;
950
951 tsec = tsk->security;
952
953 AVC_AUDIT_DATA_INIT(&ad,CAP);
954 ad.tsk = tsk;
955 ad.u.cap = cap;
956
957 return avc_has_perm(tsec->sid, tsec->sid,
958 SECCLASS_CAPABILITY, CAP_TO_MASK(cap), &ad);
959}
960
961/* Check whether a task is allowed to use a system operation. */
962static int task_has_system(struct task_struct *tsk,
963 u32 perms)
964{
965 struct task_security_struct *tsec;
966
967 tsec = tsk->security;
968
969 return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
970 SECCLASS_SYSTEM, perms, NULL);
971}
972
973/* Check whether a task has a particular permission to an inode.
974 The 'adp' parameter is optional and allows other audit
975 data to be passed (e.g. the dentry). */
976static int inode_has_perm(struct task_struct *tsk,
977 struct inode *inode,
978 u32 perms,
979 struct avc_audit_data *adp)
980{
981 struct task_security_struct *tsec;
982 struct inode_security_struct *isec;
983 struct avc_audit_data ad;
984
985 tsec = tsk->security;
986 isec = inode->i_security;
987
988 if (!adp) {
989 adp = &ad;
990 AVC_AUDIT_DATA_INIT(&ad, FS);
991 ad.u.fs.inode = inode;
992 }
993
994 return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
995}
996
997/* Same as inode_has_perm, but pass explicit audit data containing
998 the dentry to help the auditing code to more easily generate the
999 pathname if needed. */
1000static inline int dentry_has_perm(struct task_struct *tsk,
1001 struct vfsmount *mnt,
1002 struct dentry *dentry,
1003 u32 av)
1004{
1005 struct inode *inode = dentry->d_inode;
1006 struct avc_audit_data ad;
1007 AVC_AUDIT_DATA_INIT(&ad,FS);
1008 ad.u.fs.mnt = mnt;
1009 ad.u.fs.dentry = dentry;
1010 return inode_has_perm(tsk, inode, av, &ad);
1011}
1012
1013/* Check whether a task can use an open file descriptor to
1014 access an inode in a given way. Check access to the
1015 descriptor itself, and then use dentry_has_perm to
1016 check a particular permission to the file.
1017 Access to the descriptor is implicitly granted if it
1018 has the same SID as the process. If av is zero, then
1019 access to the file is not checked, e.g. for cases
1020 where only the descriptor is affected like seek. */
1021static inline int file_has_perm(struct task_struct *tsk,
1022 struct file *file,
1023 u32 av)
1024{
1025 struct task_security_struct *tsec = tsk->security;
1026 struct file_security_struct *fsec = file->f_security;
1027 struct vfsmount *mnt = file->f_vfsmnt;
1028 struct dentry *dentry = file->f_dentry;
1029 struct inode *inode = dentry->d_inode;
1030 struct avc_audit_data ad;
1031 int rc;
1032
1033 AVC_AUDIT_DATA_INIT(&ad, FS);
1034 ad.u.fs.mnt = mnt;
1035 ad.u.fs.dentry = dentry;
1036
1037 if (tsec->sid != fsec->sid) {
1038 rc = avc_has_perm(tsec->sid, fsec->sid,
1039 SECCLASS_FD,
1040 FD__USE,
1041 &ad);
1042 if (rc)
1043 return rc;
1044 }
1045
1046 /* av is zero if only checking access to the descriptor. */
1047 if (av)
1048 return inode_has_perm(tsk, inode, av, &ad);
1049
1050 return 0;
1051}
1052
1053/* Check whether a task can create a file. */
1054static int may_create(struct inode *dir,
1055 struct dentry *dentry,
1056 u16 tclass)
1057{
1058 struct task_security_struct *tsec;
1059 struct inode_security_struct *dsec;
1060 struct superblock_security_struct *sbsec;
1061 u32 newsid;
1062 struct avc_audit_data ad;
1063 int rc;
1064
1065 tsec = current->security;
1066 dsec = dir->i_security;
1067 sbsec = dir->i_sb->s_security;
1068
1069 AVC_AUDIT_DATA_INIT(&ad, FS);
1070 ad.u.fs.dentry = dentry;
1071
1072 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1073 DIR__ADD_NAME | DIR__SEARCH,
1074 &ad);
1075 if (rc)
1076 return rc;
1077
1078 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1079 newsid = tsec->create_sid;
1080 } else {
1081 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1082 &newsid);
1083 if (rc)
1084 return rc;
1085 }
1086
1087 rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1088 if (rc)
1089 return rc;
1090
1091 return avc_has_perm(newsid, sbsec->sid,
1092 SECCLASS_FILESYSTEM,
1093 FILESYSTEM__ASSOCIATE, &ad);
1094}
1095
1096#define MAY_LINK 0
1097#define MAY_UNLINK 1
1098#define MAY_RMDIR 2
1099
1100/* Check whether a task can link, unlink, or rmdir a file/directory. */
1101static int may_link(struct inode *dir,
1102 struct dentry *dentry,
1103 int kind)
1104
1105{
1106 struct task_security_struct *tsec;
1107 struct inode_security_struct *dsec, *isec;
1108 struct avc_audit_data ad;
1109 u32 av;
1110 int rc;
1111
1112 tsec = current->security;
1113 dsec = dir->i_security;
1114 isec = dentry->d_inode->i_security;
1115
1116 AVC_AUDIT_DATA_INIT(&ad, FS);
1117 ad.u.fs.dentry = dentry;
1118
1119 av = DIR__SEARCH;
1120 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1121 rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1122 if (rc)
1123 return rc;
1124
1125 switch (kind) {
1126 case MAY_LINK:
1127 av = FILE__LINK;
1128 break;
1129 case MAY_UNLINK:
1130 av = FILE__UNLINK;
1131 break;
1132 case MAY_RMDIR:
1133 av = DIR__RMDIR;
1134 break;
1135 default:
1136 printk(KERN_WARNING "may_link: unrecognized kind %d\n", kind);
1137 return 0;
1138 }
1139
1140 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1141 return rc;
1142}
1143
1144static inline int may_rename(struct inode *old_dir,
1145 struct dentry *old_dentry,
1146 struct inode *new_dir,
1147 struct dentry *new_dentry)
1148{
1149 struct task_security_struct *tsec;
1150 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1151 struct avc_audit_data ad;
1152 u32 av;
1153 int old_is_dir, new_is_dir;
1154 int rc;
1155
1156 tsec = current->security;
1157 old_dsec = old_dir->i_security;
1158 old_isec = old_dentry->d_inode->i_security;
1159 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1160 new_dsec = new_dir->i_security;
1161
1162 AVC_AUDIT_DATA_INIT(&ad, FS);
1163
1164 ad.u.fs.dentry = old_dentry;
1165 rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1166 DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1167 if (rc)
1168 return rc;
1169 rc = avc_has_perm(tsec->sid, old_isec->sid,
1170 old_isec->sclass, FILE__RENAME, &ad);
1171 if (rc)
1172 return rc;
1173 if (old_is_dir && new_dir != old_dir) {
1174 rc = avc_has_perm(tsec->sid, old_isec->sid,
1175 old_isec->sclass, DIR__REPARENT, &ad);
1176 if (rc)
1177 return rc;
1178 }
1179
1180 ad.u.fs.dentry = new_dentry;
1181 av = DIR__ADD_NAME | DIR__SEARCH;
1182 if (new_dentry->d_inode)
1183 av |= DIR__REMOVE_NAME;
1184 rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1185 if (rc)
1186 return rc;
1187 if (new_dentry->d_inode) {
1188 new_isec = new_dentry->d_inode->i_security;
1189 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1190 rc = avc_has_perm(tsec->sid, new_isec->sid,
1191 new_isec->sclass,
1192 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1193 if (rc)
1194 return rc;
1195 }
1196
1197 return 0;
1198}
1199
1200/* Check whether a task can perform a filesystem operation. */
1201static int superblock_has_perm(struct task_struct *tsk,
1202 struct super_block *sb,
1203 u32 perms,
1204 struct avc_audit_data *ad)
1205{
1206 struct task_security_struct *tsec;
1207 struct superblock_security_struct *sbsec;
1208
1209 tsec = tsk->security;
1210 sbsec = sb->s_security;
1211 return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1212 perms, ad);
1213}
1214
1215/* Convert a Linux mode and permission mask to an access vector. */
1216static inline u32 file_mask_to_av(int mode, int mask)
1217{
1218 u32 av = 0;
1219
1220 if ((mode & S_IFMT) != S_IFDIR) {
1221 if (mask & MAY_EXEC)
1222 av |= FILE__EXECUTE;
1223 if (mask & MAY_READ)
1224 av |= FILE__READ;
1225
1226 if (mask & MAY_APPEND)
1227 av |= FILE__APPEND;
1228 else if (mask & MAY_WRITE)
1229 av |= FILE__WRITE;
1230
1231 } else {
1232 if (mask & MAY_EXEC)
1233 av |= DIR__SEARCH;
1234 if (mask & MAY_WRITE)
1235 av |= DIR__WRITE;
1236 if (mask & MAY_READ)
1237 av |= DIR__READ;
1238 }
1239
1240 return av;
1241}
1242
1243/* Convert a Linux file to an access vector. */
1244static inline u32 file_to_av(struct file *file)
1245{
1246 u32 av = 0;
1247
1248 if (file->f_mode & FMODE_READ)
1249 av |= FILE__READ;
1250 if (file->f_mode & FMODE_WRITE) {
1251 if (file->f_flags & O_APPEND)
1252 av |= FILE__APPEND;
1253 else
1254 av |= FILE__WRITE;
1255 }
1256
1257 return av;
1258}
1259
1260/* Set an inode's SID to a specified value. */
1261static int inode_security_set_sid(struct inode *inode, u32 sid)
1262{
1263 struct inode_security_struct *isec = inode->i_security;
1264 struct superblock_security_struct *sbsec = inode->i_sb->s_security;
1265
1266 if (!sbsec->initialized) {
1267 /* Defer initialization to selinux_complete_init. */
1268 return 0;
1269 }
1270
1271 down(&isec->sem);
1272 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1273 isec->sid = sid;
1274 isec->initialized = 1;
1275 up(&isec->sem);
1276 return 0;
1277}
1278
1da177e4
LT		 1279/* Hook functions begin here. */
1280
1281static int selinux_ptrace(struct task_struct *parent, struct task_struct *child)
1282{
1283 struct task_security_struct *psec = parent->security;
1284 struct task_security_struct *csec = child->security;
1285 int rc;
1286
1287 rc = secondary_ops->ptrace(parent,child);
1288 if (rc)
1289 return rc;
1290
1291 rc = task_has_perm(parent, child, PROCESS__PTRACE);
1292 /* Save the SID of the tracing process for later use in apply_creds. */
1293 if (!rc)
1294 csec->ptrace_sid = psec->sid;
1295 return rc;
1296}
1297
1298static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1299 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1300{
1301 int error;
1302
1303 error = task_has_perm(current, target, PROCESS__GETCAP);
1304 if (error)
1305 return error;
1306
1307 return secondary_ops->capget(target, effective, inheritable, permitted);
1308}
1309
1310static int selinux_capset_check(struct task_struct *target, kernel_cap_t *effective,
1311 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1312{
1313 int error;
1314
1315 error = secondary_ops->capset_check(target, effective, inheritable, permitted);
1316 if (error)
1317 return error;
1318
1319 return task_has_perm(current, target, PROCESS__SETCAP);
1320}
1321
1322static void selinux_capset_set(struct task_struct *target, kernel_cap_t *effective,
1323 kernel_cap_t *inheritable, kernel_cap_t *permitted)
1324{
1325 secondary_ops->capset_set(target, effective, inheritable, permitted);
1326}
1327
1328static int selinux_capable(struct task_struct *tsk, int cap)
1329{
1330 int rc;
1331
1332 rc = secondary_ops->capable(tsk, cap);
1333 if (rc)
1334 return rc;
1335
1336 return task_has_capability(tsk,cap);
1337}
1338
1339static int selinux_sysctl(ctl_table *table, int op)
1340{
1341 int error = 0;
1342 u32 av;
1343 struct task_security_struct *tsec;
1344 u32 tsid;
1345 int rc;
1346
1347 rc = secondary_ops->sysctl(table, op);
1348 if (rc)
1349 return rc;
1350
1351 tsec = current->security;
1352
1353 rc = selinux_proc_get_sid(table->de, (op == 001) ?
1354 SECCLASS_DIR : SECCLASS_FILE, &tsid);
1355 if (rc) {
1356 /* Default to the well-defined sysctl SID. */
1357 tsid = SECINITSID_SYSCTL;
1358 }
1359
1360 /* The op values are "defined" in sysctl.c, thereby creating
1361 * a bad coupling between this module and sysctl.c */
1362 if(op == 001) {
1363 error = avc_has_perm(tsec->sid, tsid,
1364 SECCLASS_DIR, DIR__SEARCH, NULL);
1365 } else {
1366 av = 0;
1367 if (op & 004)
1368 av |= FILE__READ;
1369 if (op & 002)
1370 av |= FILE__WRITE;
1371 if (av)
1372 error = avc_has_perm(tsec->sid, tsid,
1373 SECCLASS_FILE, av, NULL);
1374 }
1375
1376 return error;
1377}
1378
1379static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1380{
1381 int rc = 0;
1382
1383 if (!sb)
1384 return 0;
1385
1386 switch (cmds) {
1387 case Q_SYNC:
1388 case Q_QUOTAON:
1389 case Q_QUOTAOFF:
1390 case Q_SETINFO:
1391 case Q_SETQUOTA:
1392 rc = superblock_has_perm(current,
1393 sb,
1394 FILESYSTEM__QUOTAMOD, NULL);
1395 break;
1396 case Q_GETFMT:
1397 case Q_GETINFO:
1398 case Q_GETQUOTA:
1399 rc = superblock_has_perm(current,
1400 sb,
1401 FILESYSTEM__QUOTAGET, NULL);
1402 break;
1403 default:
1404 rc = 0; /* let the kernel handle invalid cmds */
1405 break;
1406 }
1407 return rc;
1408}
1409
1410static int selinux_quota_on(struct dentry *dentry)
1411{
1412 return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1413}
1414
1415static int selinux_syslog(int type)
1416{
1417 int rc;
1418
1419 rc = secondary_ops->syslog(type);
1420 if (rc)
1421 return rc;
1422
1423 switch (type) {
1424 case 3: /* Read last kernel messages */
1425 case 10: /* Return size of the log buffer */
1426 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1427 break;
1428 case 6: /* Disable logging to console */
1429 case 7: /* Enable logging to console */
1430 case 8: /* Set level of messages printed to console */
1431 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1432 break;
1433 case 0: /* Close log */
1434 case 1: /* Open log */
1435 case 2: /* Read from log */
1436 case 4: /* Read/clear last kernel messages */
1437 case 5: /* Clear ring buffer */
1438 default:
1439 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1440 break;
1441 }
1442 return rc;
1443}
1444
1445/*
1446 * Check that a process has enough memory to allocate a new virtual
1447 * mapping. 0 means there is enough memory for the allocation to
1448 * succeed and -ENOMEM implies there is not.
1449 *
1450 * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1451 * if the capability is granted, but __vm_enough_memory requires 1 if
1452 * the capability is granted.
1453 *
1454 * Do not audit the selinux permission check, as this is applied to all
1455 * processes that allocate mappings.
1456 */
1457static int selinux_vm_enough_memory(long pages)
1458{
1459 int rc, cap_sys_admin = 0;
1460 struct task_security_struct *tsec = current->security;
1461
1462 rc = secondary_ops->capable(current, CAP_SYS_ADMIN);
1463 if (rc == 0)
1464 rc = avc_has_perm_noaudit(tsec->sid, tsec->sid,
1465 SECCLASS_CAPABILITY,
1466 CAP_TO_MASK(CAP_SYS_ADMIN),
1467 NULL);
1468
1469 if (rc == 0)
1470 cap_sys_admin = 1;
1471
1472 return __vm_enough_memory(pages, cap_sys_admin);
1473}
1474
1475/* binprm security operations */
1476
1477static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1478{
1479 struct bprm_security_struct *bsec;
1480
89d155ef 1481 bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1da177e4
LT		 1482 if (!bsec)
1483 return -ENOMEM;
1484
1da177e4
LT		 1485 bsec->magic = SELINUX_MAGIC;
1486 bsec->bprm = bprm;
1487 bsec->sid = SECINITSID_UNLABELED;
1488 bsec->set = 0;
1489
1490 bprm->security = bsec;
1491 return 0;
1492}
1493
1494static int selinux_bprm_set_security(struct linux_binprm *bprm)
1495{
1496 struct task_security_struct *tsec;
1497 struct inode *inode = bprm->file->f_dentry->d_inode;
1498 struct inode_security_struct *isec;
1499 struct bprm_security_struct *bsec;
1500 u32 newsid;
1501 struct avc_audit_data ad;
1502 int rc;
1503
1504 rc = secondary_ops->bprm_set_security(bprm);
1505 if (rc)
1506 return rc;
1507
1508 bsec = bprm->security;
1509
1510 if (bsec->set)
1511 return 0;
1512
1513 tsec = current->security;
1514 isec = inode->i_security;
1515
1516 /* Default to the current task SID. */
1517 bsec->sid = tsec->sid;
1518
1519 /* Reset create SID on execve. */
1520 tsec->create_sid = 0;
1521
1522 if (tsec->exec_sid) {
1523 newsid = tsec->exec_sid;
1524 /* Reset exec SID on execve. */
1525 tsec->exec_sid = 0;
1526 } else {
1527 /* Check for a default transition on this program. */
1528 rc = security_transition_sid(tsec->sid, isec->sid,
1529 SECCLASS_PROCESS, &newsid);
1530 if (rc)
1531 return rc;
1532 }
1533
1534 AVC_AUDIT_DATA_INIT(&ad, FS);
1535 ad.u.fs.mnt = bprm->file->f_vfsmnt;
1536 ad.u.fs.dentry = bprm->file->f_dentry;
1537
1538 if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID)
1539 newsid = tsec->sid;
1540
1541 if (tsec->sid == newsid) {
1542 rc = avc_has_perm(tsec->sid, isec->sid,
1543 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
1544 if (rc)
1545 return rc;
1546 } else {
1547 /* Check permissions for the transition. */
1548 rc = avc_has_perm(tsec->sid, newsid,
1549 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
1550 if (rc)
1551 return rc;
1552
1553 rc = avc_has_perm(newsid, isec->sid,
1554 SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
1555 if (rc)
1556 return rc;
1557
1558 /* Clear any possibly unsafe personality bits on exec: */
1559 current->personality &= ~PER_CLEAR_ON_SETID;
1560
1561 /* Set the security field to the new SID. */
1562 bsec->sid = newsid;
1563 }
1564
1565 bsec->set = 1;
1566 return 0;
1567}
1568
1569static int selinux_bprm_check_security (struct linux_binprm *bprm)
1570{
1571 return secondary_ops->bprm_check_security(bprm);
1572}
1573
1574
1575static int selinux_bprm_secureexec (struct linux_binprm *bprm)
1576{
1577 struct task_security_struct *tsec = current->security;
1578 int atsecure = 0;
1579
1580 if (tsec->osid != tsec->sid) {
1581 /* Enable secure mode for SIDs transitions unless
1582 the noatsecure permission is granted between
1583 the two SIDs, i.e. ahp returns 0. */
1584 atsecure = avc_has_perm(tsec->osid, tsec->sid,
1585 SECCLASS_PROCESS,
1586 PROCESS__NOATSECURE, NULL);
1587 }
1588
1589 return (atsecure || secondary_ops->bprm_secureexec(bprm));
1590}
1591
1592static void selinux_bprm_free_security(struct linux_binprm *bprm)
1593{
9a5f04bf 1594 kfree(bprm->security);
1da177e4 1595 bprm->security = NULL;
1da177e4
LT		 1596}
1597
1598extern struct vfsmount *selinuxfs_mount;
1599extern struct dentry *selinux_null;
1600
1601/* Derived from fs/exec.c:flush_old_files. */
1602static inline void flush_unauthorized_files(struct files_struct * files)
1603{
1604 struct avc_audit_data ad;
1605 struct file *file, *devnull = NULL;
1606 struct tty_struct *tty = current->signal->tty;
badf1662 1607 struct fdtable *fdt;
1da177e4
LT		 1608 long j = -1;
1609
1610 if (tty) {
1611 file_list_lock();
2f512016 1612 file = list_entry(tty->tty_files.next, typeof(*file), f_u.fu_list);
1da177e4
LT		 1613 if (file) {
1614 /* Revalidate access to controlling tty.
1615 Use inode_has_perm on the tty inode directly rather
1616 than using file_has_perm, as this particular open
1617 file may belong to another process and we are only
1618 interested in the inode-based check here. */
1619 struct inode *inode = file->f_dentry->d_inode;
1620 if (inode_has_perm(current, inode,
1621 FILE__READ | FILE__WRITE, NULL)) {
1622 /* Reset controlling tty. */
1623 current->signal->tty = NULL;
1624 current->signal->tty_old_pgrp = 0;
1625 }
1626 }
1627 file_list_unlock();
1628 }
1629
1630 /* Revalidate access to inherited open files. */
1631
1632 AVC_AUDIT_DATA_INIT(&ad,FS);
1633
1634 spin_lock(&files->file_lock);
1635 for (;;) {
1636 unsigned long set, i;
1637 int fd;
1638
1639 j++;
1640 i = j * __NFDBITS;
badf1662
DS		 1641 fdt = files_fdtable(files);
1642 if (i >= fdt->max_fds || i >= fdt->max_fdset)
1da177e4 1643 break;
badf1662 1644 set = fdt->open_fds->fds_bits[j];
1da177e4
LT		 1645 if (!set)
1646 continue;
1647 spin_unlock(&files->file_lock);
1648 for ( ; set ; i++,set >>= 1) {
1649 if (set & 1) {
1650 file = fget(i);
1651 if (!file)
1652 continue;
1653 if (file_has_perm(current,
1654 file,
1655 file_to_av(file))) {
1656 sys_close(i);
1657 fd = get_unused_fd();
1658 if (fd != i) {
1659 if (fd >= 0)
1660 put_unused_fd(fd);
1661 fput(file);
1662 continue;
1663 }
1664 if (devnull) {
b835996f 1665 rcuref_inc(&devnull->f_count);
1da177e4
LT		 1666 } else {
1667 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
1668 if (!devnull) {
1669 put_unused_fd(fd);
1670 fput(file);
1671 continue;
1672 }
1673 }
1674 fd_install(fd, devnull);
1675 }
1676 fput(file);
1677 }
1678 }
1679 spin_lock(&files->file_lock);
1680
1681 }
1682 spin_unlock(&files->file_lock);
1683}
1684
1685static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
1686{
1687 struct task_security_struct *tsec;
1688 struct bprm_security_struct *bsec;
1689 u32 sid;
1690 int rc;
1691
1692 secondary_ops->bprm_apply_creds(bprm, unsafe);
1693
1694 tsec = current->security;
1695
1696 bsec = bprm->security;
1697 sid = bsec->sid;
1698
1699 tsec->osid = tsec->sid;
1700 bsec->unsafe = 0;
1701 if (tsec->sid != sid) {
1702 /* Check for shared state. If not ok, leave SID
1703 unchanged and kill. */
1704 if (unsafe & LSM_UNSAFE_SHARE) {
1705 rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
1706 PROCESS__SHARE, NULL);
1707 if (rc) {
1708 bsec->unsafe = 1;
1709 return;
1710 }
1711 }
1712
1713 /* Check for ptracing, and update the task SID if ok.
1714 Otherwise, leave SID unchanged and kill. */
1715 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
1716 rc = avc_has_perm(tsec->ptrace_sid, sid,
1717 SECCLASS_PROCESS, PROCESS__PTRACE,
1718 NULL);
1719 if (rc) {
1720 bsec->unsafe = 1;
1721 return;
1722 }
1723 }
1724 tsec->sid = sid;
1725 }
1726}
1727
1728/*
1729 * called after apply_creds without the task lock held
1730 */
1731static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
1732{
1733 struct task_security_struct *tsec;
1734 struct rlimit *rlim, *initrlim;
1735 struct itimerval itimer;
1736 struct bprm_security_struct *bsec;
1737 int rc, i;
1738
1739 tsec = current->security;
1740 bsec = bprm->security;
1741
1742 if (bsec->unsafe) {
1743 force_sig_specific(SIGKILL, current);
1744 return;
1745 }
1746 if (tsec->osid == tsec->sid)
1747 return;
1748
1749 /* Close files for which the new task SID is not authorized. */
1750 flush_unauthorized_files(current->files);
1751
1752 /* Check whether the new SID can inherit signal state
1753 from the old SID. If not, clear itimers to avoid
1754 subsequent signal generation and flush and unblock
1755 signals. This must occur _after_ the task SID has
1756 been updated so that any kill done after the flush
1757 will be checked against the new SID. */
1758 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1759 PROCESS__SIGINH, NULL);
1760 if (rc) {
1761 memset(&itimer, 0, sizeof itimer);
1762 for (i = 0; i < 3; i++)
1763 do_setitimer(i, &itimer, NULL);
1764 flush_signals(current);
1765 spin_lock_irq(&current->sighand->siglock);
1766 flush_signal_handlers(current, 1);
1767 sigemptyset(&current->blocked);
1768 recalc_sigpending();
1769 spin_unlock_irq(&current->sighand->siglock);
1770 }
1771
1772 /* Check whether the new SID can inherit resource limits
1773 from the old SID. If not, reset all soft limits to
1774 the lower of the current task's hard limit and the init
1775 task's soft limit. Note that the setting of hard limits
1776 (even to lower them) can be controlled by the setrlimit
1777 check. The inclusion of the init task's soft limit into
1778 the computation is to avoid resetting soft limits higher
1779 than the default soft limit for cases where the default
1780 is lower than the hard limit, e.g. RLIMIT_CORE or
1781 RLIMIT_STACK.*/
1782 rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
1783 PROCESS__RLIMITINH, NULL);
1784 if (rc) {
1785 for (i = 0; i < RLIM_NLIMITS; i++) {
1786 rlim = current->signal->rlim + i;
1787 initrlim = init_task.signal->rlim+i;
1788 rlim->rlim_cur = min(rlim->rlim_max,initrlim->rlim_cur);
1789 }
1790 if (current->signal->rlim[RLIMIT_CPU].rlim_cur != RLIM_INFINITY) {
1791 /*
1792 * This will cause RLIMIT_CPU calculations
1793 * to be refigured.
1794 */
1795 current->it_prof_expires = jiffies_to_cputime(1);
1796 }
1797 }
1798
1799 /* Wake up the parent if it is waiting so that it can
1800 recheck wait permission to the new task SID. */
1801 wake_up_interruptible(&current->parent->signal->wait_chldexit);
1802}
1803
1804/* superblock security operations */
1805
1806static int selinux_sb_alloc_security(struct super_block *sb)
1807{
1808 return superblock_alloc_security(sb);
1809}
1810
1811static void selinux_sb_free_security(struct super_block *sb)
1812{
1813 superblock_free_security(sb);
1814}
1815
1816static inline int match_prefix(char *prefix, int plen, char *option, int olen)
1817{
1818 if (plen > olen)
1819 return 0;
1820
1821 return !memcmp(prefix, option, plen);
1822}
1823
1824static inline int selinux_option(char *option, int len)
1825{
1826 return (match_prefix("context=", sizeof("context=")-1, option, len) ||
1827 match_prefix("fscontext=", sizeof("fscontext=")-1, option, len) ||
1828 match_prefix("defcontext=", sizeof("defcontext=")-1, option, len));
1829}
1830
1831static inline void take_option(char **to, char *from, int *first, int len)
1832{
1833 if (!*first) {
1834 **to = ',';
1835 *to += 1;
1836 }
1837 else
1838 *first = 0;
1839 memcpy(*to, from, len);
1840 *to += len;
1841}
1842
1843static int selinux_sb_copy_data(struct file_system_type *type, void *orig, void *copy)
1844{
1845 int fnosec, fsec, rc = 0;
1846 char *in_save, *in_curr, *in_end;
1847 char *sec_curr, *nosec_save, *nosec;
1848
1849 in_curr = orig;
1850 sec_curr = copy;
1851
1852 /* Binary mount data: just copy */
1853 if (type->fs_flags & FS_BINARY_MOUNTDATA) {
1854 copy_page(sec_curr, in_curr);
1855 goto out;
1856 }
1857
1858 nosec = (char *)get_zeroed_page(GFP_KERNEL);
1859 if (!nosec) {
1860 rc = -ENOMEM;
1861 goto out;
1862 }
1863
1864 nosec_save = nosec;
1865 fnosec = fsec = 1;
1866 in_save = in_end = orig;
1867
1868 do {
1869 if (*in_end == ',' || *in_end == '\0') {
1870 int len = in_end - in_curr;
1871
1872 if (selinux_option(in_curr, len))
1873 take_option(&sec_curr, in_curr, &fsec, len);
1874 else
1875 take_option(&nosec, in_curr, &fnosec, len);
1876
1877 in_curr = in_end + 1;
1878 }
1879 } while (*in_end++);
1880
6931dfc9 1881 strcpy(in_save, nosec_save);
da3caa20 1882 free_page((unsigned long)nosec_save);
1da177e4
LT		 1883out:
1884 return rc;
1885}
1886
1887static int selinux_sb_kern_mount(struct super_block *sb, void *data)
1888{
1889 struct avc_audit_data ad;
1890 int rc;
1891
1892 rc = superblock_doinit(sb, data);
1893 if (rc)
1894 return rc;
1895
1896 AVC_AUDIT_DATA_INIT(&ad,FS);
1897 ad.u.fs.dentry = sb->s_root;
1898 return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
1899}
1900
1901static int selinux_sb_statfs(struct super_block *sb)
1902{
1903 struct avc_audit_data ad;
1904
1905 AVC_AUDIT_DATA_INIT(&ad,FS);
1906 ad.u.fs.dentry = sb->s_root;
1907 return superblock_has_perm(current, sb, FILESYSTEM__GETATTR, &ad);
1908}
1909
1910static int selinux_mount(char * dev_name,
1911 struct nameidata *nd,
1912 char * type,
1913 unsigned long flags,
1914 void * data)
1915{
1916 int rc;
1917
1918 rc = secondary_ops->sb_mount(dev_name, nd, type, flags, data);
1919 if (rc)
1920 return rc;
1921
1922 if (flags & MS_REMOUNT)
1923 return superblock_has_perm(current, nd->mnt->mnt_sb,
1924 FILESYSTEM__REMOUNT, NULL);
1925 else
1926 return dentry_has_perm(current, nd->mnt, nd->dentry,
1927 FILE__MOUNTON);
1928}
1929
1930static int selinux_umount(struct vfsmount *mnt, int flags)
1931{
1932 int rc;
1933
1934 rc = secondary_ops->sb_umount(mnt, flags);
1935 if (rc)
1936 return rc;
1937
1938 return superblock_has_perm(current,mnt->mnt_sb,
1939 FILESYSTEM__UNMOUNT,NULL);
1940}
1941
1942/* inode security operations */
1943
1944static int selinux_inode_alloc_security(struct inode *inode)
1945{
1946 return inode_alloc_security(inode);
1947}
1948
1949static void selinux_inode_free_security(struct inode *inode)
1950{
1951 inode_free_security(inode);
1952}
1953
5e41ff9e
SS		 1954static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
1955 char **name, void **value,
1956 size_t *len)
1957{
1958 struct task_security_struct *tsec;
1959 struct inode_security_struct *dsec;
1960 struct superblock_security_struct *sbsec;
1961 struct inode_security_struct *isec;
570bc1c2 1962 u32 newsid, clen;
5e41ff9e 1963 int rc;
570bc1c2 1964 char *namep = NULL, *context;
5e41ff9e
SS		 1965
1966 tsec = current->security;
1967 dsec = dir->i_security;
1968 sbsec = dir->i_sb->s_security;
1969 isec = inode->i_security;
1970
1971 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1972 newsid = tsec->create_sid;
1973 } else {
1974 rc = security_transition_sid(tsec->sid, dsec->sid,
1975 inode_mode_to_security_class(inode->i_mode),
1976 &newsid);
1977 if (rc) {
1978 printk(KERN_WARNING "%s: "
1979 "security_transition_sid failed, rc=%d (dev=%s "
1980 "ino=%ld)\n",
1981 __FUNCTION__,
1982 -rc, inode->i_sb->s_id, inode->i_ino);
1983 return rc;
1984 }
1985 }
1986
1987 inode_security_set_sid(inode, newsid);
1988
25a74f3b
SS		 1989 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
1990 return -EOPNOTSUPP;
1991
570bc1c2
SS		 1992 if (name) {
1993 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_KERNEL);
1994 if (!namep)
1995 return -ENOMEM;
1996 *name = namep;
1997 }
5e41ff9e 1998
570bc1c2
SS		 1999 if (value && len) {
2000 rc = security_sid_to_context(newsid, &context, &clen);
2001 if (rc) {
2002 kfree(namep);
2003 return rc;
2004 }
2005 *value = context;
2006 *len = clen;
5e41ff9e 2007 }
5e41ff9e 2008
5e41ff9e
SS		 2009 return 0;
2010}
2011
1da177e4
LT		 2012static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2013{
2014 return may_create(dir, dentry, SECCLASS_FILE);
2015}
2016
1da177e4
LT		 2017static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2018{
2019 int rc;
2020
2021 rc = secondary_ops->inode_link(old_dentry,dir,new_dentry);
2022 if (rc)
2023 return rc;
2024 return may_link(dir, old_dentry, MAY_LINK);
2025}
2026
1da177e4
LT		 2027static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2028{
2029 int rc;
2030
2031 rc = secondary_ops->inode_unlink(dir, dentry);
2032 if (rc)
2033 return rc;
2034 return may_link(dir, dentry, MAY_UNLINK);
2035}
2036
2037static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2038{
2039 return may_create(dir, dentry, SECCLASS_LNK_FILE);
2040}
2041
1da177e4
LT		 2042static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2043{
2044 return may_create(dir, dentry, SECCLASS_DIR);
2045}
2046
1da177e4
LT		 2047static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2048{
2049 return may_link(dir, dentry, MAY_RMDIR);
2050}
2051
2052static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2053{
2054 int rc;
2055
2056 rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2057 if (rc)
2058 return rc;
2059
2060 return may_create(dir, dentry, inode_mode_to_security_class(mode));
2061}
2062
1da177e4
LT		 2063static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2064 struct inode *new_inode, struct dentry *new_dentry)
2065{
2066 return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2067}
2068
1da177e4
LT		 2069static int selinux_inode_readlink(struct dentry *dentry)
2070{
2071 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2072}
2073
2074static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2075{
2076 int rc;
2077
2078 rc = secondary_ops->inode_follow_link(dentry,nameidata);
2079 if (rc)
2080 return rc;
2081 return dentry_has_perm(current, NULL, dentry, FILE__READ);
2082}
2083
2084static int selinux_inode_permission(struct inode *inode, int mask,
2085 struct nameidata *nd)
2086{
2087 int rc;
2088
2089 rc = secondary_ops->inode_permission(inode, mask, nd);
2090 if (rc)
2091 return rc;
2092
2093 if (!mask) {
2094 /* No permission to check. Existence test. */
2095 return 0;
2096 }
2097
2098 return inode_has_perm(current, inode,
2099 file_mask_to_av(inode->i_mode, mask), NULL);
2100}
2101
2102static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2103{
2104 int rc;
2105
2106 rc = secondary_ops->inode_setattr(dentry, iattr);
2107 if (rc)
2108 return rc;
2109
2110 if (iattr->ia_valid & ATTR_FORCE)
2111 return 0;
2112
2113 if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2114 ATTR_ATIME_SET | ATTR_MTIME_SET))
2115 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2116
2117 return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2118}
2119
2120static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2121{
2122 return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2123}
2124
2125static int selinux_inode_setxattr(struct dentry *dentry, char *name, void *value, size_t size, int flags)
2126{
2127 struct task_security_struct *tsec = current->security;
2128 struct inode *inode = dentry->d_inode;
2129 struct inode_security_struct *isec = inode->i_security;
2130 struct superblock_security_struct *sbsec;
2131 struct avc_audit_data ad;
2132 u32 newsid;
2133 int rc = 0;
2134
2135 if (strcmp(name, XATTR_NAME_SELINUX)) {
2136 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2137 sizeof XATTR_SECURITY_PREFIX - 1) &&
2138 !capable(CAP_SYS_ADMIN)) {
2139 /* A different attribute in the security namespace.
2140 Restrict to administrator. */
2141 return -EPERM;
2142 }
2143
2144 /* Not an attribute we recognize, so just check the
2145 ordinary setattr permission. */
2146 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2147 }
2148
2149 sbsec = inode->i_sb->s_security;
2150 if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2151 return -EOPNOTSUPP;
2152
2153 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
2154 return -EPERM;
2155
2156 AVC_AUDIT_DATA_INIT(&ad,FS);
2157 ad.u.fs.dentry = dentry;
2158
2159 rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2160 FILE__RELABELFROM, &ad);
2161 if (rc)
2162 return rc;
2163
2164 rc = security_context_to_sid(value, size, &newsid);
2165 if (rc)
2166 return rc;
2167
2168 rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2169 FILE__RELABELTO, &ad);
2170 if (rc)
2171 return rc;
2172
2173 rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2174 isec->sclass);
2175 if (rc)
2176 return rc;
2177
2178 return avc_has_perm(newsid,
2179 sbsec->sid,
2180 SECCLASS_FILESYSTEM,
2181 FILESYSTEM__ASSOCIATE,
2182 &ad);
2183}
2184
2185static void selinux_inode_post_setxattr(struct dentry *dentry, char *name,
2186 void *value, size_t size, int flags)
2187{
2188 struct inode *inode = dentry->d_inode;
2189 struct inode_security_struct *isec = inode->i_security;
2190 u32 newsid;
2191 int rc;
2192
2193 if (strcmp(name, XATTR_NAME_SELINUX)) {
2194 /* Not an attribute we recognize, so nothing to do. */
2195 return;
2196 }
2197
2198 rc = security_context_to_sid(value, size, &newsid);
2199 if (rc) {
2200 printk(KERN_WARNING "%s: unable to obtain SID for context "
2201 "%s, rc=%d\n", __FUNCTION__, (char*)value, -rc);
2202 return;
2203 }
2204
2205 isec->sid = newsid;
2206 return;
2207}
2208
2209static int selinux_inode_getxattr (struct dentry *dentry, char *name)
2210{
1da177e4
LT		 2211 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2212}
2213
2214static int selinux_inode_listxattr (struct dentry *dentry)
2215{
2216 return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2217}
2218
2219static int selinux_inode_removexattr (struct dentry *dentry, char *name)
2220{
2221 if (strcmp(name, XATTR_NAME_SELINUX)) {
2222 if (!strncmp(name, XATTR_SECURITY_PREFIX,
2223 sizeof XATTR_SECURITY_PREFIX - 1) &&
2224 !capable(CAP_SYS_ADMIN)) {
2225 /* A different attribute in the security namespace.
2226 Restrict to administrator. */
2227 return -EPERM;
2228 }
2229
2230 /* Not an attribute we recognize, so just check the
2231 ordinary setattr permission. Might want a separate
2232 permission for removexattr. */
2233 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2234 }
2235
2236 /* No one is allowed to remove a SELinux security label.
2237 You can change the label, but all data must be labeled. */
2238 return -EACCES;
2239}
2240
d381d8a9
JM		 2241/*
2242 * Copy the in-core inode security context value to the user. If the
2243 * getxattr() prior to this succeeded, check to see if we need to
2244 * canonicalize the value to be finally returned to the user.
2245 *
2246 * Permission check is handled by selinux_inode_getxattr hook.
2247 */
2248static int selinux_inode_getsecurity(struct inode *inode, const char *name, void *buffer, size_t size, int err)
1da177e4
LT		 2249{
2250 struct inode_security_struct *isec = inode->i_security;
2251 char *context;
2252 unsigned len;
2253 int rc;
2254
d381d8a9
JM		 2255 if (strcmp(name, XATTR_SELINUX_SUFFIX)) {
2256 rc = -EOPNOTSUPP;
2257 goto out;
2258 }
1da177e4
LT		 2259
2260 rc = security_sid_to_context(isec->sid, &context, &len);
2261 if (rc)
d381d8a9 2262 goto out;
1da177e4 2263
d381d8a9 2264 /* Probe for required buffer size */
1da177e4 2265 if (!buffer || !size) {
d381d8a9
JM		 2266 rc = len;
2267 goto out_free;
1da177e4 2268 }
d381d8a9 2269
1da177e4 2270 if (size < len) {
d381d8a9
JM		 2271 rc = -ERANGE;
2272 goto out_free;
2273 }
2274
2275 if (err > 0) {
2276 if ((len == err) && !(memcmp(context, buffer, len))) {
2277 /* Don't need to canonicalize value */
2278 rc = err;
2279 goto out_free;
2280 }
2281 memset(buffer, 0, size);
1da177e4
LT		 2282 }
2283 memcpy(buffer, context, len);
d381d8a9
JM		 2284 rc = len;
2285out_free:
1da177e4 2286 kfree(context);
d381d8a9
JM		 2287out:
2288 return rc;
1da177e4
LT		 2289}
2290
2291static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2292 const void *value, size_t size, int flags)
2293{
2294 struct inode_security_struct *isec = inode->i_security;
2295 u32 newsid;
2296 int rc;
2297
2298 if (strcmp(name, XATTR_SELINUX_SUFFIX))
2299 return -EOPNOTSUPP;
2300
2301 if (!value || !size)
2302 return -EACCES;
2303
2304 rc = security_context_to_sid((void*)value, size, &newsid);
2305 if (rc)
2306 return rc;
2307
2308 isec->sid = newsid;
2309 return 0;
2310}
2311
2312static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2313{
2314 const int len = sizeof(XATTR_NAME_SELINUX);
2315 if (buffer && len <= buffer_size)
2316 memcpy(buffer, XATTR_NAME_SELINUX, len);
2317 return len;
2318}
2319
2320/* file security operations */
2321
2322static int selinux_file_permission(struct file *file, int mask)
2323{
2324 struct inode *inode = file->f_dentry->d_inode;
2325
2326 if (!mask) {
2327 /* No permission to check. Existence test. */
2328 return 0;
2329 }
2330
2331 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2332 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2333 mask |= MAY_APPEND;
2334
2335 return file_has_perm(current, file,
2336 file_mask_to_av(inode->i_mode, mask));
2337}
2338
2339static int selinux_file_alloc_security(struct file *file)
2340{
2341 return file_alloc_security(file);
2342}
2343
2344static void selinux_file_free_security(struct file *file)
2345{
2346 file_free_security(file);
2347}
2348
2349static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2350 unsigned long arg)
2351{
2352 int error = 0;
2353
2354 switch (cmd) {
2355 case FIONREAD:
2356 /* fall through */
2357 case FIBMAP:
2358 /* fall through */
2359 case FIGETBSZ:
2360 /* fall through */
2361 case EXT2_IOC_GETFLAGS:
2362 /* fall through */
2363 case EXT2_IOC_GETVERSION:
2364 error = file_has_perm(current, file, FILE__GETATTR);
2365 break;
2366
2367 case EXT2_IOC_SETFLAGS:
2368 /* fall through */
2369 case EXT2_IOC_SETVERSION:
2370 error = file_has_perm(current, file, FILE__SETATTR);
2371 break;
2372
2373 /* sys_ioctl() checks */
2374 case FIONBIO:
2375 /* fall through */
2376 case FIOASYNC:
2377 error = file_has_perm(current, file, 0);
2378 break;
2379
2380 case KDSKBENT:
2381 case KDSKBSENT:
2382 error = task_has_capability(current,CAP_SYS_TTY_CONFIG);
2383 break;
2384
2385 /* default case assumes that the command will go
2386 * to the file's ioctl() function.
2387 */
2388 default:
2389 error = file_has_perm(current, file, FILE__IOCTL);
2390
2391 }
2392 return error;
2393}
2394
2395static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2396{
2397#ifndef CONFIG_PPC32
2398 if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2399 /*
2400 * We are making executable an anonymous mapping or a
2401 * private file mapping that will also be writable.
2402 * This has an additional check.
2403 */
2404 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2405 if (rc)
2406 return rc;
2407 }
2408#endif
2409
2410 if (file) {
2411 /* read access is always possible with a mapping */
2412 u32 av = FILE__READ;
2413
2414 /* write access only matters if the mapping is shared */
2415 if (shared && (prot & PROT_WRITE))
2416 av |= FILE__WRITE;
2417
2418 if (prot & PROT_EXEC)
2419 av |= FILE__EXECUTE;
2420
2421 return file_has_perm(current, file, av);
2422 }
2423 return 0;
2424}
2425
2426static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2427 unsigned long prot, unsigned long flags)
2428{
2429 int rc;
2430
2431 rc = secondary_ops->file_mmap(file, reqprot, prot, flags);
2432 if (rc)
2433 return rc;
2434
2435 if (selinux_checkreqprot)
2436 prot = reqprot;
2437
2438 return file_map_prot_check(file, prot,
2439 (flags & MAP_TYPE) == MAP_SHARED);
2440}
2441
2442static int selinux_file_mprotect(struct vm_area_struct *vma,
2443 unsigned long reqprot,
2444 unsigned long prot)
2445{
2446 int rc;
2447
2448 rc = secondary_ops->file_mprotect(vma, reqprot, prot);
2449 if (rc)
2450 return rc;
2451
2452 if (selinux_checkreqprot)
2453 prot = reqprot;
2454
2455#ifndef CONFIG_PPC32