]>
Commit | Line | Data |
---|---|---|
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> | |
828dfe1d EP |
7 | * Chris Vance, <cvance@nai.com> |
8 | * Wayne Salamon, <wsalamon@nai.com> | |
9 | * James Morris <jmorris@redhat.com> | |
1da177e4 LT |
10 | * |
11 | * Copyright (C) 2001,2002 Networks Associates Technology, Inc. | |
2069f457 EP |
12 | * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com> |
13 | * Eric Paris <eparis@redhat.com> | |
1da177e4 | 14 | * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. |
828dfe1d | 15 | * <dgoeddel@trustedcs.com> |
ed6d76e4 | 16 | * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P. |
82c21bfa | 17 | * Paul Moore <paul@paul-moore.com> |
788e7dd4 | 18 | * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. |
828dfe1d | 19 | * Yuichi Nakamura <ynakam@hitachisoft.jp> |
1da177e4 LT |
20 | * |
21 | * This program is free software; you can redistribute it and/or modify | |
22 | * it under the terms of the GNU General Public License version 2, | |
828dfe1d | 23 | * as published by the Free Software Foundation. |
1da177e4 LT |
24 | */ |
25 | ||
1da177e4 | 26 | #include <linux/init.h> |
0b24dcb7 | 27 | #include <linux/kd.h> |
1da177e4 | 28 | #include <linux/kernel.h> |
0d094efe | 29 | #include <linux/tracehook.h> |
1da177e4 | 30 | #include <linux/errno.h> |
0b24dcb7 | 31 | #include <linux/ext2_fs.h> |
1da177e4 LT |
32 | #include <linux/sched.h> |
33 | #include <linux/security.h> | |
34 | #include <linux/xattr.h> | |
35 | #include <linux/capability.h> | |
36 | #include <linux/unistd.h> | |
37 | #include <linux/mm.h> | |
38 | #include <linux/mman.h> | |
39 | #include <linux/slab.h> | |
40 | #include <linux/pagemap.h> | |
0b24dcb7 | 41 | #include <linux/proc_fs.h> |
1da177e4 | 42 | #include <linux/swap.h> |
1da177e4 LT |
43 | #include <linux/spinlock.h> |
44 | #include <linux/syscalls.h> | |
2a7dba39 | 45 | #include <linux/dcache.h> |
1da177e4 | 46 | #include <linux/file.h> |
9f3acc31 | 47 | #include <linux/fdtable.h> |
1da177e4 LT |
48 | #include <linux/namei.h> |
49 | #include <linux/mount.h> | |
1da177e4 LT |
50 | #include <linux/netfilter_ipv4.h> |
51 | #include <linux/netfilter_ipv6.h> | |
52 | #include <linux/tty.h> | |
53 | #include <net/icmp.h> | |
227b60f5 | 54 | #include <net/ip.h> /* for local_port_range[] */ |
1da177e4 | 55 | #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ |
220deb96 | 56 | #include <net/net_namespace.h> |
d621d35e | 57 | #include <net/netlabel.h> |
f5269710 | 58 | #include <linux/uaccess.h> |
1da177e4 | 59 | #include <asm/ioctls.h> |
60063497 | 60 | #include <linux/atomic.h> |
1da177e4 LT |
61 | #include <linux/bitops.h> |
62 | #include <linux/interrupt.h> | |
63 | #include <linux/netdevice.h> /* for network interface checks */ | |
64 | #include <linux/netlink.h> | |
65 | #include <linux/tcp.h> | |
66 | #include <linux/udp.h> | |
2ee92d46 | 67 | #include <linux/dccp.h> |
1da177e4 LT |
68 | #include <linux/quota.h> |
69 | #include <linux/un.h> /* for Unix socket types */ | |
70 | #include <net/af_unix.h> /* for Unix socket types */ | |
71 | #include <linux/parser.h> | |
72 | #include <linux/nfs_mount.h> | |
73 | #include <net/ipv6.h> | |
74 | #include <linux/hugetlb.h> | |
75 | #include <linux/personality.h> | |
1da177e4 | 76 | #include <linux/audit.h> |
6931dfc9 | 77 | #include <linux/string.h> |
877ce7c1 | 78 | #include <linux/selinux.h> |
23970741 | 79 | #include <linux/mutex.h> |
f06febc9 | 80 | #include <linux/posix-timers.h> |
00234592 | 81 | #include <linux/syslog.h> |
3486740a | 82 | #include <linux/user_namespace.h> |
44fc7ea0 | 83 | #include <linux/export.h> |
1da177e4 LT |
84 | |
85 | #include "avc.h" | |
86 | #include "objsec.h" | |
87 | #include "netif.h" | |
224dfbd8 | 88 | #include "netnode.h" |
3e112172 | 89 | #include "netport.h" |
d28d1e08 | 90 | #include "xfrm.h" |
c60475bf | 91 | #include "netlabel.h" |
9d57a7f9 | 92 | #include "audit.h" |
7b98a585 | 93 | #include "avc_ss.h" |
1da177e4 | 94 | |
11689d47 | 95 | #define NUM_SEL_MNT_OPTS 5 |
c9180a57 | 96 | |
20510f2f | 97 | extern struct security_operations *security_ops; |
1da177e4 | 98 | |
d621d35e | 99 | /* SECMARK reference count */ |
56a4ca99 | 100 | static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); |
d621d35e | 101 | |
1da177e4 | 102 | #ifdef CONFIG_SECURITY_SELINUX_DEVELOP |
828dfe1d | 103 | int selinux_enforcing; |
1da177e4 LT |
104 | |
105 | static int __init enforcing_setup(char *str) | |
106 | { | |
f5269710 EP |
107 | unsigned long enforcing; |
108 | if (!strict_strtoul(str, 0, &enforcing)) | |
109 | selinux_enforcing = enforcing ? 1 : 0; | |
1da177e4 LT |
110 | return 1; |
111 | } | |
112 | __setup("enforcing=", enforcing_setup); | |
113 | #endif | |
114 | ||
115 | #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM | |
116 | int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; | |
117 | ||
118 | static int __init selinux_enabled_setup(char *str) | |
119 | { | |
f5269710 EP |
120 | unsigned long enabled; |
121 | if (!strict_strtoul(str, 0, &enabled)) | |
122 | selinux_enabled = enabled ? 1 : 0; | |
1da177e4 LT |
123 | return 1; |
124 | } | |
125 | __setup("selinux=", selinux_enabled_setup); | |
30d55280 SS |
126 | #else |
127 | int selinux_enabled = 1; | |
1da177e4 LT |
128 | #endif |
129 | ||
e18b890b | 130 | static struct kmem_cache *sel_inode_cache; |
7cae7e26 | 131 | |
d621d35e PM |
132 | /** |
133 | * selinux_secmark_enabled - Check to see if SECMARK is currently enabled | |
134 | * | |
135 | * Description: | |
136 | * This function checks the SECMARK reference counter to see if any SECMARK | |
137 | * targets are currently configured, if the reference counter is greater than | |
138 | * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is | |
139 | * enabled, false (0) if SECMARK is disabled. | |
140 | * | |
141 | */ | |
142 | static int selinux_secmark_enabled(void) | |
143 | { | |
144 | return (atomic_read(&selinux_secmark_refcount) > 0); | |
145 | } | |
146 | ||
d84f4f99 DH |
147 | /* |
148 | * initialise the security for the init task | |
149 | */ | |
150 | static void cred_init_security(void) | |
1da177e4 | 151 | { |
3b11a1de | 152 | struct cred *cred = (struct cred *) current->real_cred; |
1da177e4 LT |
153 | struct task_security_struct *tsec; |
154 | ||
89d155ef | 155 | tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); |
1da177e4 | 156 | if (!tsec) |
d84f4f99 | 157 | panic("SELinux: Failed to initialize initial task.\n"); |
1da177e4 | 158 | |
d84f4f99 | 159 | tsec->osid = tsec->sid = SECINITSID_KERNEL; |
f1752eec | 160 | cred->security = tsec; |
1da177e4 LT |
161 | } |
162 | ||
88e67f3b DH |
163 | /* |
164 | * get the security ID of a set of credentials | |
165 | */ | |
166 | static inline u32 cred_sid(const struct cred *cred) | |
167 | { | |
168 | const struct task_security_struct *tsec; | |
169 | ||
170 | tsec = cred->security; | |
171 | return tsec->sid; | |
172 | } | |
173 | ||
275bb41e | 174 | /* |
3b11a1de | 175 | * get the objective security ID of a task |
275bb41e DH |
176 | */ |
177 | static inline u32 task_sid(const struct task_struct *task) | |
178 | { | |
275bb41e DH |
179 | u32 sid; |
180 | ||
181 | rcu_read_lock(); | |
88e67f3b | 182 | sid = cred_sid(__task_cred(task)); |
275bb41e DH |
183 | rcu_read_unlock(); |
184 | return sid; | |
185 | } | |
186 | ||
187 | /* | |
3b11a1de | 188 | * get the subjective security ID of the current task |
275bb41e DH |
189 | */ |
190 | static inline u32 current_sid(void) | |
191 | { | |
5fb49870 | 192 | const struct task_security_struct *tsec = current_security(); |
275bb41e DH |
193 | |
194 | return tsec->sid; | |
195 | } | |
196 | ||
88e67f3b DH |
197 | /* Allocate and free functions for each kind of security blob. */ |
198 | ||
1da177e4 LT |
199 | static int inode_alloc_security(struct inode *inode) |
200 | { | |
1da177e4 | 201 | struct inode_security_struct *isec; |
275bb41e | 202 | u32 sid = current_sid(); |
1da177e4 | 203 | |
a02fe132 | 204 | isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); |
1da177e4 LT |
205 | if (!isec) |
206 | return -ENOMEM; | |
207 | ||
23970741 | 208 | mutex_init(&isec->lock); |
1da177e4 | 209 | INIT_LIST_HEAD(&isec->list); |
1da177e4 LT |
210 | isec->inode = inode; |
211 | isec->sid = SECINITSID_UNLABELED; | |
212 | isec->sclass = SECCLASS_FILE; | |
275bb41e | 213 | isec->task_sid = sid; |
1da177e4 LT |
214 | inode->i_security = isec; |
215 | ||
216 | return 0; | |
217 | } | |
218 | ||
219 | static void inode_free_security(struct inode *inode) | |
220 | { | |
221 | struct inode_security_struct *isec = inode->i_security; | |
222 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; | |
223 | ||
1da177e4 LT |
224 | spin_lock(&sbsec->isec_lock); |
225 | if (!list_empty(&isec->list)) | |
226 | list_del_init(&isec->list); | |
227 | spin_unlock(&sbsec->isec_lock); | |
228 | ||
229 | inode->i_security = NULL; | |
7cae7e26 | 230 | kmem_cache_free(sel_inode_cache, isec); |
1da177e4 LT |
231 | } |
232 | ||
233 | static int file_alloc_security(struct file *file) | |
234 | { | |
1da177e4 | 235 | struct file_security_struct *fsec; |
275bb41e | 236 | u32 sid = current_sid(); |
1da177e4 | 237 | |
26d2a4be | 238 | fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); |
1da177e4 LT |
239 | if (!fsec) |
240 | return -ENOMEM; | |
241 | ||
275bb41e DH |
242 | fsec->sid = sid; |
243 | fsec->fown_sid = sid; | |
1da177e4 LT |
244 | file->f_security = fsec; |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
249 | static void file_free_security(struct file *file) | |
250 | { | |
251 | struct file_security_struct *fsec = file->f_security; | |
1da177e4 LT |
252 | file->f_security = NULL; |
253 | kfree(fsec); | |
254 | } | |
255 | ||
256 | static int superblock_alloc_security(struct super_block *sb) | |
257 | { | |
258 | struct superblock_security_struct *sbsec; | |
259 | ||
89d155ef | 260 | sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); |
1da177e4 LT |
261 | if (!sbsec) |
262 | return -ENOMEM; | |
263 | ||
bc7e982b | 264 | mutex_init(&sbsec->lock); |
1da177e4 LT |
265 | INIT_LIST_HEAD(&sbsec->isec_head); |
266 | spin_lock_init(&sbsec->isec_lock); | |
1da177e4 LT |
267 | sbsec->sb = sb; |
268 | sbsec->sid = SECINITSID_UNLABELED; | |
269 | sbsec->def_sid = SECINITSID_FILE; | |
c312feb2 | 270 | sbsec->mntpoint_sid = SECINITSID_UNLABELED; |
1da177e4 LT |
271 | sb->s_security = sbsec; |
272 | ||
273 | return 0; | |
274 | } | |
275 | ||
276 | static void superblock_free_security(struct super_block *sb) | |
277 | { | |
278 | struct superblock_security_struct *sbsec = sb->s_security; | |
1da177e4 LT |
279 | sb->s_security = NULL; |
280 | kfree(sbsec); | |
281 | } | |
282 | ||
1da177e4 LT |
283 | /* The file system's label must be initialized prior to use. */ |
284 | ||
634a539e | 285 | static const char *labeling_behaviors[6] = { |
1da177e4 LT |
286 | "uses xattr", |
287 | "uses transition SIDs", | |
288 | "uses task SIDs", | |
289 | "uses genfs_contexts", | |
290 | "not configured for labeling", | |
291 | "uses mountpoint labeling", | |
292 | }; | |
293 | ||
294 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); | |
295 | ||
296 | static inline int inode_doinit(struct inode *inode) | |
297 | { | |
298 | return inode_doinit_with_dentry(inode, NULL); | |
299 | } | |
300 | ||
301 | enum { | |
31e87930 | 302 | Opt_error = -1, |
1da177e4 LT |
303 | Opt_context = 1, |
304 | Opt_fscontext = 2, | |
c9180a57 EP |
305 | Opt_defcontext = 3, |
306 | Opt_rootcontext = 4, | |
11689d47 | 307 | Opt_labelsupport = 5, |
1da177e4 LT |
308 | }; |
309 | ||
a447c093 | 310 | static const match_table_t tokens = { |
832cbd9a EP |
311 | {Opt_context, CONTEXT_STR "%s"}, |
312 | {Opt_fscontext, FSCONTEXT_STR "%s"}, | |
313 | {Opt_defcontext, DEFCONTEXT_STR "%s"}, | |
314 | {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, | |
11689d47 | 315 | {Opt_labelsupport, LABELSUPP_STR}, |
31e87930 | 316 | {Opt_error, NULL}, |
1da177e4 LT |
317 | }; |
318 | ||
319 | #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" | |
320 | ||
c312feb2 EP |
321 | static int may_context_mount_sb_relabel(u32 sid, |
322 | struct superblock_security_struct *sbsec, | |
275bb41e | 323 | const struct cred *cred) |
c312feb2 | 324 | { |
275bb41e | 325 | const struct task_security_struct *tsec = cred->security; |
c312feb2 EP |
326 | int rc; |
327 | ||
328 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
329 | FILESYSTEM__RELABELFROM, NULL); | |
330 | if (rc) | |
331 | return rc; | |
332 | ||
333 | rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, | |
334 | FILESYSTEM__RELABELTO, NULL); | |
335 | return rc; | |
336 | } | |
337 | ||
0808925e EP |
338 | static int may_context_mount_inode_relabel(u32 sid, |
339 | struct superblock_security_struct *sbsec, | |
275bb41e | 340 | const struct cred *cred) |
0808925e | 341 | { |
275bb41e | 342 | const struct task_security_struct *tsec = cred->security; |
0808925e EP |
343 | int rc; |
344 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
345 | FILESYSTEM__RELABELFROM, NULL); | |
346 | if (rc) | |
347 | return rc; | |
348 | ||
349 | rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
350 | FILESYSTEM__ASSOCIATE, NULL); | |
351 | return rc; | |
352 | } | |
353 | ||
c9180a57 | 354 | static int sb_finish_set_opts(struct super_block *sb) |
1da177e4 | 355 | { |
1da177e4 | 356 | struct superblock_security_struct *sbsec = sb->s_security; |
c9180a57 EP |
357 | struct dentry *root = sb->s_root; |
358 | struct inode *root_inode = root->d_inode; | |
359 | int rc = 0; | |
1da177e4 | 360 | |
c9180a57 EP |
361 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { |
362 | /* Make sure that the xattr handler exists and that no | |
363 | error other than -ENODATA is returned by getxattr on | |
364 | the root directory. -ENODATA is ok, as this may be | |
365 | the first boot of the SELinux kernel before we have | |
366 | assigned xattr values to the filesystem. */ | |
367 | if (!root_inode->i_op->getxattr) { | |
368 | printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " | |
369 | "xattr support\n", sb->s_id, sb->s_type->name); | |
370 | rc = -EOPNOTSUPP; | |
371 | goto out; | |
372 | } | |
373 | rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0); | |
374 | if (rc < 0 && rc != -ENODATA) { | |
375 | if (rc == -EOPNOTSUPP) | |
376 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
377 | "%s) has no security xattr handler\n", | |
378 | sb->s_id, sb->s_type->name); | |
379 | else | |
380 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
381 | "%s) getxattr errno %d\n", sb->s_id, | |
382 | sb->s_type->name, -rc); | |
383 | goto out; | |
384 | } | |
385 | } | |
1da177e4 | 386 | |
11689d47 | 387 | sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP); |
1da177e4 | 388 | |
c9180a57 EP |
389 | if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) |
390 | printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", | |
391 | sb->s_id, sb->s_type->name); | |
392 | else | |
393 | printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n", | |
394 | sb->s_id, sb->s_type->name, | |
395 | labeling_behaviors[sbsec->behavior-1]); | |
1da177e4 | 396 | |
11689d47 DQ |
397 | if (sbsec->behavior == SECURITY_FS_USE_GENFS || |
398 | sbsec->behavior == SECURITY_FS_USE_MNTPOINT || | |
399 | sbsec->behavior == SECURITY_FS_USE_NONE || | |
400 | sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) | |
401 | sbsec->flags &= ~SE_SBLABELSUPP; | |
402 | ||
ddd29ec6 DQ |
403 | /* Special handling for sysfs. Is genfs but also has setxattr handler*/ |
404 | if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0) | |
405 | sbsec->flags |= SE_SBLABELSUPP; | |
406 | ||
c9180a57 EP |
407 | /* Initialize the root inode. */ |
408 | rc = inode_doinit_with_dentry(root_inode, root); | |
1da177e4 | 409 | |
c9180a57 EP |
410 | /* Initialize any other inodes associated with the superblock, e.g. |
411 | inodes created prior to initial policy load or inodes created | |
412 | during get_sb by a pseudo filesystem that directly | |
413 | populates itself. */ | |
414 | spin_lock(&sbsec->isec_lock); | |
415 | next_inode: | |
416 | if (!list_empty(&sbsec->isec_head)) { | |
417 | struct inode_security_struct *isec = | |
418 | list_entry(sbsec->isec_head.next, | |
419 | struct inode_security_struct, list); | |
420 | struct inode *inode = isec->inode; | |
421 | spin_unlock(&sbsec->isec_lock); | |
422 | inode = igrab(inode); | |
423 | if (inode) { | |
424 | if (!IS_PRIVATE(inode)) | |
425 | inode_doinit(inode); | |
426 | iput(inode); | |
427 | } | |
428 | spin_lock(&sbsec->isec_lock); | |
429 | list_del_init(&isec->list); | |
430 | goto next_inode; | |
431 | } | |
432 | spin_unlock(&sbsec->isec_lock); | |
433 | out: | |
434 | return rc; | |
435 | } | |
1da177e4 | 436 | |
c9180a57 EP |
437 | /* |
438 | * This function should allow an FS to ask what it's mount security | |
439 | * options were so it can use those later for submounts, displaying | |
440 | * mount options, or whatever. | |
441 | */ | |
442 | static int selinux_get_mnt_opts(const struct super_block *sb, | |
e0007529 | 443 | struct security_mnt_opts *opts) |
c9180a57 EP |
444 | { |
445 | int rc = 0, i; | |
446 | struct superblock_security_struct *sbsec = sb->s_security; | |
447 | char *context = NULL; | |
448 | u32 len; | |
449 | char tmp; | |
1da177e4 | 450 | |
e0007529 | 451 | security_init_mnt_opts(opts); |
1da177e4 | 452 | |
0d90a7ec | 453 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
c9180a57 | 454 | return -EINVAL; |
1da177e4 | 455 | |
c9180a57 EP |
456 | if (!ss_initialized) |
457 | return -EINVAL; | |
1da177e4 | 458 | |
0d90a7ec | 459 | tmp = sbsec->flags & SE_MNTMASK; |
c9180a57 EP |
460 | /* count the number of mount options for this sb */ |
461 | for (i = 0; i < 8; i++) { | |
462 | if (tmp & 0x01) | |
e0007529 | 463 | opts->num_mnt_opts++; |
c9180a57 EP |
464 | tmp >>= 1; |
465 | } | |
11689d47 DQ |
466 | /* Check if the Label support flag is set */ |
467 | if (sbsec->flags & SE_SBLABELSUPP) | |
468 | opts->num_mnt_opts++; | |
1da177e4 | 469 | |
e0007529 EP |
470 | opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); |
471 | if (!opts->mnt_opts) { | |
c9180a57 EP |
472 | rc = -ENOMEM; |
473 | goto out_free; | |
474 | } | |
1da177e4 | 475 | |
e0007529 EP |
476 | opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); |
477 | if (!opts->mnt_opts_flags) { | |
c9180a57 EP |
478 | rc = -ENOMEM; |
479 | goto out_free; | |
480 | } | |
1da177e4 | 481 | |
c9180a57 EP |
482 | i = 0; |
483 | if (sbsec->flags & FSCONTEXT_MNT) { | |
484 | rc = security_sid_to_context(sbsec->sid, &context, &len); | |
485 | if (rc) | |
486 | goto out_free; | |
e0007529 EP |
487 | opts->mnt_opts[i] = context; |
488 | opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; | |
c9180a57 EP |
489 | } |
490 | if (sbsec->flags & CONTEXT_MNT) { | |
491 | rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); | |
492 | if (rc) | |
493 | goto out_free; | |
e0007529 EP |
494 | opts->mnt_opts[i] = context; |
495 | opts->mnt_opts_flags[i++] = CONTEXT_MNT; | |
c9180a57 EP |
496 | } |
497 | if (sbsec->flags & DEFCONTEXT_MNT) { | |
498 | rc = security_sid_to_context(sbsec->def_sid, &context, &len); | |
499 | if (rc) | |
500 | goto out_free; | |
e0007529 EP |
501 | opts->mnt_opts[i] = context; |
502 | opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; | |
c9180a57 EP |
503 | } |
504 | if (sbsec->flags & ROOTCONTEXT_MNT) { | |
505 | struct inode *root = sbsec->sb->s_root->d_inode; | |
506 | struct inode_security_struct *isec = root->i_security; | |
0808925e | 507 | |
c9180a57 EP |
508 | rc = security_sid_to_context(isec->sid, &context, &len); |
509 | if (rc) | |
510 | goto out_free; | |
e0007529 EP |
511 | opts->mnt_opts[i] = context; |
512 | opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; | |
c9180a57 | 513 | } |
11689d47 DQ |
514 | if (sbsec->flags & SE_SBLABELSUPP) { |
515 | opts->mnt_opts[i] = NULL; | |
516 | opts->mnt_opts_flags[i++] = SE_SBLABELSUPP; | |
517 | } | |
1da177e4 | 518 | |
e0007529 | 519 | BUG_ON(i != opts->num_mnt_opts); |
1da177e4 | 520 | |
c9180a57 EP |
521 | return 0; |
522 | ||
523 | out_free: | |
e0007529 | 524 | security_free_mnt_opts(opts); |
c9180a57 EP |
525 | return rc; |
526 | } | |
1da177e4 | 527 | |
c9180a57 EP |
528 | static int bad_option(struct superblock_security_struct *sbsec, char flag, |
529 | u32 old_sid, u32 new_sid) | |
530 | { | |
0d90a7ec DQ |
531 | char mnt_flags = sbsec->flags & SE_MNTMASK; |
532 | ||
c9180a57 | 533 | /* check if the old mount command had the same options */ |
0d90a7ec | 534 | if (sbsec->flags & SE_SBINITIALIZED) |
c9180a57 EP |
535 | if (!(sbsec->flags & flag) || |
536 | (old_sid != new_sid)) | |
537 | return 1; | |
538 | ||
539 | /* check if we were passed the same options twice, | |
540 | * aka someone passed context=a,context=b | |
541 | */ | |
0d90a7ec DQ |
542 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
543 | if (mnt_flags & flag) | |
c9180a57 EP |
544 | return 1; |
545 | return 0; | |
546 | } | |
e0007529 | 547 | |
c9180a57 EP |
548 | /* |
549 | * Allow filesystems with binary mount data to explicitly set mount point | |
550 | * labeling information. | |
551 | */ | |
e0007529 EP |
552 | static int selinux_set_mnt_opts(struct super_block *sb, |
553 | struct security_mnt_opts *opts) | |
c9180a57 | 554 | { |
275bb41e | 555 | const struct cred *cred = current_cred(); |
c9180a57 | 556 | int rc = 0, i; |
c9180a57 EP |
557 | struct superblock_security_struct *sbsec = sb->s_security; |
558 | const char *name = sb->s_type->name; | |
089be43e JM |
559 | struct inode *inode = sbsec->sb->s_root->d_inode; |
560 | struct inode_security_struct *root_isec = inode->i_security; | |
c9180a57 EP |
561 | u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; |
562 | u32 defcontext_sid = 0; | |
e0007529 EP |
563 | char **mount_options = opts->mnt_opts; |
564 | int *flags = opts->mnt_opts_flags; | |
565 | int num_opts = opts->num_mnt_opts; | |
c9180a57 EP |
566 | |
567 | mutex_lock(&sbsec->lock); | |
568 | ||
569 | if (!ss_initialized) { | |
570 | if (!num_opts) { | |
571 | /* Defer initialization until selinux_complete_init, | |
572 | after the initial policy is loaded and the security | |
573 | server is ready to handle calls. */ | |
c9180a57 EP |
574 | goto out; |
575 | } | |
576 | rc = -EINVAL; | |
744ba35e EP |
577 | printk(KERN_WARNING "SELinux: Unable to set superblock options " |
578 | "before the security server is initialized\n"); | |
1da177e4 | 579 | goto out; |
c9180a57 | 580 | } |
1da177e4 | 581 | |
e0007529 EP |
582 | /* |
583 | * Binary mount data FS will come through this function twice. Once | |
584 | * from an explicit call and once from the generic calls from the vfs. | |
585 | * Since the generic VFS calls will not contain any security mount data | |
586 | * we need to skip the double mount verification. | |
587 | * | |
588 | * This does open a hole in which we will not notice if the first | |
589 | * mount using this sb set explict options and a second mount using | |
590 | * this sb does not set any security options. (The first options | |
591 | * will be used for both mounts) | |
592 | */ | |
0d90a7ec | 593 | if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) |
e0007529 | 594 | && (num_opts == 0)) |
f5269710 | 595 | goto out; |
e0007529 | 596 | |
c9180a57 EP |
597 | /* |
598 | * parse the mount options, check if they are valid sids. | |
599 | * also check if someone is trying to mount the same sb more | |
600 | * than once with different security options. | |
601 | */ | |
602 | for (i = 0; i < num_opts; i++) { | |
603 | u32 sid; | |
11689d47 DQ |
604 | |
605 | if (flags[i] == SE_SBLABELSUPP) | |
606 | continue; | |
c9180a57 EP |
607 | rc = security_context_to_sid(mount_options[i], |
608 | strlen(mount_options[i]), &sid); | |
1da177e4 LT |
609 | if (rc) { |
610 | printk(KERN_WARNING "SELinux: security_context_to_sid" | |
611 | "(%s) failed for (dev %s, type %s) errno=%d\n", | |
c9180a57 EP |
612 | mount_options[i], sb->s_id, name, rc); |
613 | goto out; | |
614 | } | |
615 | switch (flags[i]) { | |
616 | case FSCONTEXT_MNT: | |
617 | fscontext_sid = sid; | |
618 | ||
619 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, | |
620 | fscontext_sid)) | |
621 | goto out_double_mount; | |
622 | ||
623 | sbsec->flags |= FSCONTEXT_MNT; | |
624 | break; | |
625 | case CONTEXT_MNT: | |
626 | context_sid = sid; | |
627 | ||
628 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, | |
629 | context_sid)) | |
630 | goto out_double_mount; | |
631 | ||
632 | sbsec->flags |= CONTEXT_MNT; | |
633 | break; | |
634 | case ROOTCONTEXT_MNT: | |
635 | rootcontext_sid = sid; | |
636 | ||
637 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, | |
638 | rootcontext_sid)) | |
639 | goto out_double_mount; | |
640 | ||
641 | sbsec->flags |= ROOTCONTEXT_MNT; | |
642 | ||
643 | break; | |
644 | case DEFCONTEXT_MNT: | |
645 | defcontext_sid = sid; | |
646 | ||
647 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, | |
648 | defcontext_sid)) | |
649 | goto out_double_mount; | |
650 | ||
651 | sbsec->flags |= DEFCONTEXT_MNT; | |
652 | ||
653 | break; | |
654 | default: | |
655 | rc = -EINVAL; | |
656 | goto out; | |
1da177e4 | 657 | } |
c9180a57 EP |
658 | } |
659 | ||
0d90a7ec | 660 | if (sbsec->flags & SE_SBINITIALIZED) { |
c9180a57 | 661 | /* previously mounted with options, but not on this attempt? */ |
0d90a7ec | 662 | if ((sbsec->flags & SE_MNTMASK) && !num_opts) |
c9180a57 EP |
663 | goto out_double_mount; |
664 | rc = 0; | |
665 | goto out; | |
666 | } | |
667 | ||
089be43e | 668 | if (strcmp(sb->s_type->name, "proc") == 0) |
0d90a7ec | 669 | sbsec->flags |= SE_SBPROC; |
c9180a57 EP |
670 | |
671 | /* Determine the labeling behavior to use for this filesystem type. */ | |
0d90a7ec | 672 | rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid); |
c9180a57 EP |
673 | if (rc) { |
674 | printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n", | |
089be43e | 675 | __func__, sb->s_type->name, rc); |
c9180a57 EP |
676 | goto out; |
677 | } | |
1da177e4 | 678 | |
c9180a57 EP |
679 | /* sets the context of the superblock for the fs being mounted. */ |
680 | if (fscontext_sid) { | |
275bb41e | 681 | rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); |
1da177e4 | 682 | if (rc) |
c9180a57 | 683 | goto out; |
1da177e4 | 684 | |
c9180a57 | 685 | sbsec->sid = fscontext_sid; |
c312feb2 EP |
686 | } |
687 | ||
688 | /* | |
689 | * Switch to using mount point labeling behavior. | |
690 | * sets the label used on all file below the mountpoint, and will set | |
691 | * the superblock context if not already set. | |
692 | */ | |
c9180a57 EP |
693 | if (context_sid) { |
694 | if (!fscontext_sid) { | |
275bb41e DH |
695 | rc = may_context_mount_sb_relabel(context_sid, sbsec, |
696 | cred); | |
b04ea3ce | 697 | if (rc) |
c9180a57 EP |
698 | goto out; |
699 | sbsec->sid = context_sid; | |
b04ea3ce | 700 | } else { |
275bb41e DH |
701 | rc = may_context_mount_inode_relabel(context_sid, sbsec, |
702 | cred); | |
b04ea3ce | 703 | if (rc) |
c9180a57 | 704 | goto out; |
b04ea3ce | 705 | } |
c9180a57 EP |
706 | if (!rootcontext_sid) |
707 | rootcontext_sid = context_sid; | |
1da177e4 | 708 | |
c9180a57 | 709 | sbsec->mntpoint_sid = context_sid; |
c312feb2 | 710 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; |
1da177e4 LT |
711 | } |
712 | ||
c9180a57 | 713 | if (rootcontext_sid) { |
275bb41e DH |
714 | rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, |
715 | cred); | |
0808925e | 716 | if (rc) |
c9180a57 | 717 | goto out; |
0808925e | 718 | |
c9180a57 EP |
719 | root_isec->sid = rootcontext_sid; |
720 | root_isec->initialized = 1; | |
0808925e EP |
721 | } |
722 | ||
c9180a57 EP |
723 | if (defcontext_sid) { |
724 | if (sbsec->behavior != SECURITY_FS_USE_XATTR) { | |
725 | rc = -EINVAL; | |
726 | printk(KERN_WARNING "SELinux: defcontext option is " | |
727 | "invalid for this filesystem type\n"); | |
728 | goto out; | |
1da177e4 LT |
729 | } |
730 | ||
c9180a57 EP |
731 | if (defcontext_sid != sbsec->def_sid) { |
732 | rc = may_context_mount_inode_relabel(defcontext_sid, | |
275bb41e | 733 | sbsec, cred); |
c9180a57 EP |
734 | if (rc) |
735 | goto out; | |
736 | } | |
1da177e4 | 737 | |
c9180a57 | 738 | sbsec->def_sid = defcontext_sid; |
1da177e4 LT |
739 | } |
740 | ||
c9180a57 | 741 | rc = sb_finish_set_opts(sb); |
1da177e4 | 742 | out: |
c9180a57 | 743 | mutex_unlock(&sbsec->lock); |
1da177e4 | 744 | return rc; |
c9180a57 EP |
745 | out_double_mount: |
746 | rc = -EINVAL; | |
747 | printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " | |
748 | "security settings for (dev %s, type %s)\n", sb->s_id, name); | |
749 | goto out; | |
1da177e4 LT |
750 | } |
751 | ||
c9180a57 EP |
752 | static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb, |
753 | struct super_block *newsb) | |
1da177e4 | 754 | { |
c9180a57 EP |
755 | const struct superblock_security_struct *oldsbsec = oldsb->s_security; |
756 | struct superblock_security_struct *newsbsec = newsb->s_security; | |
1da177e4 | 757 | |
c9180a57 EP |
758 | int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); |
759 | int set_context = (oldsbsec->flags & CONTEXT_MNT); | |
760 | int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); | |
1da177e4 | 761 | |
0f5e6420 EP |
762 | /* |
763 | * if the parent was able to be mounted it clearly had no special lsm | |
e8c26255 | 764 | * mount options. thus we can safely deal with this superblock later |
0f5e6420 | 765 | */ |
e8c26255 | 766 | if (!ss_initialized) |
0f5e6420 | 767 | return; |
c9180a57 | 768 | |
c9180a57 | 769 | /* how can we clone if the old one wasn't set up?? */ |
0d90a7ec | 770 | BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); |
c9180a57 | 771 | |
5a552617 | 772 | /* if fs is reusing a sb, just let its options stand... */ |
0d90a7ec | 773 | if (newsbsec->flags & SE_SBINITIALIZED) |
5a552617 EP |
774 | return; |
775 | ||
c9180a57 EP |
776 | mutex_lock(&newsbsec->lock); |
777 | ||
778 | newsbsec->flags = oldsbsec->flags; | |
779 | ||
780 | newsbsec->sid = oldsbsec->sid; | |
781 | newsbsec->def_sid = oldsbsec->def_sid; | |
782 | newsbsec->behavior = oldsbsec->behavior; | |
783 | ||
784 | if (set_context) { | |
785 | u32 sid = oldsbsec->mntpoint_sid; | |
786 | ||
787 | if (!set_fscontext) | |
788 | newsbsec->sid = sid; | |
789 | if (!set_rootcontext) { | |
790 | struct inode *newinode = newsb->s_root->d_inode; | |
791 | struct inode_security_struct *newisec = newinode->i_security; | |
792 | newisec->sid = sid; | |
793 | } | |
794 | newsbsec->mntpoint_sid = sid; | |
1da177e4 | 795 | } |
c9180a57 EP |
796 | if (set_rootcontext) { |
797 | const struct inode *oldinode = oldsb->s_root->d_inode; | |
798 | const struct inode_security_struct *oldisec = oldinode->i_security; | |
799 | struct inode *newinode = newsb->s_root->d_inode; | |
800 | struct inode_security_struct *newisec = newinode->i_security; | |
1da177e4 | 801 | |
c9180a57 | 802 | newisec->sid = oldisec->sid; |
1da177e4 LT |
803 | } |
804 | ||
c9180a57 EP |
805 | sb_finish_set_opts(newsb); |
806 | mutex_unlock(&newsbsec->lock); | |
807 | } | |
808 | ||
2e1479d9 AB |
809 | static int selinux_parse_opts_str(char *options, |
810 | struct security_mnt_opts *opts) | |
c9180a57 | 811 | { |
e0007529 | 812 | char *p; |
c9180a57 EP |
813 | char *context = NULL, *defcontext = NULL; |
814 | char *fscontext = NULL, *rootcontext = NULL; | |
e0007529 | 815 | int rc, num_mnt_opts = 0; |
1da177e4 | 816 | |
e0007529 | 817 | opts->num_mnt_opts = 0; |
1da177e4 | 818 | |
c9180a57 EP |
819 | /* Standard string-based options. */ |
820 | while ((p = strsep(&options, "|")) != NULL) { | |
821 | int token; | |
822 | substring_t args[MAX_OPT_ARGS]; | |
1da177e4 | 823 | |
c9180a57 EP |
824 | if (!*p) |
825 | continue; | |
1da177e4 | 826 | |
c9180a57 | 827 | token = match_token(p, tokens, args); |
1da177e4 | 828 | |
c9180a57 EP |
829 | switch (token) { |
830 | case Opt_context: | |
831 | if (context || defcontext) { | |
832 | rc = -EINVAL; | |
833 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
834 | goto out_err; | |
835 | } | |
836 | context = match_strdup(&args[0]); | |
837 | if (!context) { | |
838 | rc = -ENOMEM; | |
839 | goto out_err; | |
840 | } | |
841 | break; | |
842 | ||
843 | case Opt_fscontext: | |
844 | if (fscontext) { | |
845 | rc = -EINVAL; | |
846 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
847 | goto out_err; | |
848 | } | |
849 | fscontext = match_strdup(&args[0]); | |
850 | if (!fscontext) { | |
851 | rc = -ENOMEM; | |
852 | goto out_err; | |
853 | } | |
854 | break; | |
855 | ||
856 | case Opt_rootcontext: | |
857 | if (rootcontext) { | |
858 | rc = -EINVAL; | |
859 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
860 | goto out_err; | |
861 | } | |
862 | rootcontext = match_strdup(&args[0]); | |
863 | if (!rootcontext) { | |
864 | rc = -ENOMEM; | |
865 | goto out_err; | |
866 | } | |
867 | break; | |
868 | ||
869 | case Opt_defcontext: | |
870 | if (context || defcontext) { | |
871 | rc = -EINVAL; | |
872 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
873 | goto out_err; | |
874 | } | |
875 | defcontext = match_strdup(&args[0]); | |
876 | if (!defcontext) { | |
877 | rc = -ENOMEM; | |
878 | goto out_err; | |
879 | } | |
880 | break; | |
11689d47 DQ |
881 | case Opt_labelsupport: |
882 | break; | |
c9180a57 EP |
883 | default: |
884 | rc = -EINVAL; | |
885 | printk(KERN_WARNING "SELinux: unknown mount option\n"); | |
886 | goto out_err; | |
1da177e4 | 887 | |
1da177e4 | 888 | } |
1da177e4 | 889 | } |
c9180a57 | 890 | |
e0007529 EP |
891 | rc = -ENOMEM; |
892 | opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC); | |
893 | if (!opts->mnt_opts) | |
894 | goto out_err; | |
895 | ||
896 | opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC); | |
897 | if (!opts->mnt_opts_flags) { | |
898 | kfree(opts->mnt_opts); | |
899 | goto out_err; | |
900 | } | |
901 | ||
c9180a57 | 902 | if (fscontext) { |
e0007529 EP |
903 | opts->mnt_opts[num_mnt_opts] = fscontext; |
904 | opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; | |
c9180a57 EP |
905 | } |
906 | if (context) { | |
e0007529 EP |
907 | opts->mnt_opts[num_mnt_opts] = context; |
908 | opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; | |
c9180a57 EP |
909 | } |
910 | if (rootcontext) { | |
e0007529 EP |
911 | opts->mnt_opts[num_mnt_opts] = rootcontext; |
912 | opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; | |
c9180a57 EP |
913 | } |
914 | if (defcontext) { | |
e0007529 EP |
915 | opts->mnt_opts[num_mnt_opts] = defcontext; |
916 | opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; | |
c9180a57 EP |
917 | } |
918 | ||
e0007529 EP |
919 | opts->num_mnt_opts = num_mnt_opts; |
920 | return 0; | |
921 | ||
c9180a57 EP |
922 | out_err: |
923 | kfree(context); | |
924 | kfree(defcontext); | |
925 | kfree(fscontext); | |
926 | kfree(rootcontext); | |
1da177e4 LT |
927 | return rc; |
928 | } | |
e0007529 EP |
929 | /* |
930 | * string mount options parsing and call set the sbsec | |
931 | */ | |
932 | static int superblock_doinit(struct super_block *sb, void *data) | |
933 | { | |
934 | int rc = 0; | |
935 | char *options = data; | |
936 | struct security_mnt_opts opts; | |
937 | ||
938 | security_init_mnt_opts(&opts); | |
939 | ||
940 | if (!data) | |
941 | goto out; | |
942 | ||
943 | BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); | |
944 | ||
945 | rc = selinux_parse_opts_str(options, &opts); | |
946 | if (rc) | |
947 | goto out_err; | |
948 | ||
949 | out: | |
950 | rc = selinux_set_mnt_opts(sb, &opts); | |
951 | ||
952 | out_err: | |
953 | security_free_mnt_opts(&opts); | |
954 | return rc; | |
955 | } | |
1da177e4 | 956 | |
3583a711 AB |
957 | static void selinux_write_opts(struct seq_file *m, |
958 | struct security_mnt_opts *opts) | |
2069f457 EP |
959 | { |
960 | int i; | |
961 | char *prefix; | |
962 | ||
963 | for (i = 0; i < opts->num_mnt_opts; i++) { | |
11689d47 DQ |
964 | char *has_comma; |
965 | ||
966 | if (opts->mnt_opts[i]) | |
967 | has_comma = strchr(opts->mnt_opts[i], ','); | |
968 | else | |
969 | has_comma = NULL; | |
2069f457 EP |
970 | |
971 | switch (opts->mnt_opts_flags[i]) { | |
972 | case CONTEXT_MNT: | |
973 | prefix = CONTEXT_STR; | |
974 | break; | |
975 | case FSCONTEXT_MNT: | |
976 | prefix = FSCONTEXT_STR; | |
977 | break; | |
978 | case ROOTCONTEXT_MNT: | |
979 | prefix = ROOTCONTEXT_STR; | |
980 | break; | |
981 | case DEFCONTEXT_MNT: | |
982 | prefix = DEFCONTEXT_STR; | |
983 | break; | |
11689d47 DQ |
984 | case SE_SBLABELSUPP: |
985 | seq_putc(m, ','); | |
986 | seq_puts(m, LABELSUPP_STR); | |
987 | continue; | |
2069f457 EP |
988 | default: |
989 | BUG(); | |
a35c6c83 | 990 | return; |
2069f457 EP |
991 | }; |
992 | /* we need a comma before each option */ | |
993 | seq_putc(m, ','); | |
994 | seq_puts(m, prefix); | |
995 | if (has_comma) | |
996 | seq_putc(m, '\"'); | |
997 | seq_puts(m, opts->mnt_opts[i]); | |
998 | if (has_comma) | |
999 | seq_putc(m, '\"'); | |
1000 | } | |
1001 | } | |
1002 | ||
1003 | static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) | |
1004 | { | |
1005 | struct security_mnt_opts opts; | |
1006 | int rc; | |
1007 | ||
1008 | rc = selinux_get_mnt_opts(sb, &opts); | |
383795c2 EP |
1009 | if (rc) { |
1010 | /* before policy load we may get EINVAL, don't show anything */ | |
1011 | if (rc == -EINVAL) | |
1012 | rc = 0; | |
2069f457 | 1013 | return rc; |
383795c2 | 1014 | } |
2069f457 EP |
1015 | |
1016 | selinux_write_opts(m, &opts); | |
1017 | ||
1018 | security_free_mnt_opts(&opts); | |
1019 | ||
1020 | return rc; | |
1021 | } | |
1022 | ||
1da177e4 LT |
1023 | static inline u16 inode_mode_to_security_class(umode_t mode) |
1024 | { | |
1025 | switch (mode & S_IFMT) { | |
1026 | case S_IFSOCK: | |
1027 | return SECCLASS_SOCK_FILE; | |
1028 | case S_IFLNK: | |
1029 | return SECCLASS_LNK_FILE; | |
1030 | case S_IFREG: | |
1031 | return SECCLASS_FILE; | |
1032 | case S_IFBLK: | |
1033 | return SECCLASS_BLK_FILE; | |
1034 | case S_IFDIR: | |
1035 | return SECCLASS_DIR; | |
1036 | case S_IFCHR: | |
1037 | return SECCLASS_CHR_FILE; | |
1038 | case S_IFIFO: | |
1039 | return SECCLASS_FIFO_FILE; | |
1040 | ||
1041 | } | |
1042 | ||
1043 | return SECCLASS_FILE; | |
1044 | } | |
1045 | ||
13402580 JM |
1046 | static inline int default_protocol_stream(int protocol) |
1047 | { | |
1048 | return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); | |
1049 | } | |
1050 | ||
1051 | static inline int default_protocol_dgram(int protocol) | |
1052 | { | |
1053 | return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); | |
1054 | } | |
1055 | ||
1da177e4 LT |
1056 | static inline u16 socket_type_to_security_class(int family, int type, int protocol) |
1057 | { | |
1058 | switch (family) { | |
1059 | case PF_UNIX: | |
1060 | switch (type) { | |
1061 | case SOCK_STREAM: | |
1062 | case SOCK_SEQPACKET: | |
1063 | return SECCLASS_UNIX_STREAM_SOCKET; | |
1064 | case SOCK_DGRAM: | |
1065 | return SECCLASS_UNIX_DGRAM_SOCKET; | |
1066 | } | |
1067 | break; | |
1068 | case PF_INET: | |
1069 | case PF_INET6: | |
1070 | switch (type) { | |
1071 | case SOCK_STREAM: | |
13402580 JM |
1072 | if (default_protocol_stream(protocol)) |
1073 | return SECCLASS_TCP_SOCKET; | |
1074 | else | |
1075 | return SECCLASS_RAWIP_SOCKET; | |
1da177e4 | 1076 | case SOCK_DGRAM: |
13402580 JM |
1077 | if (default_protocol_dgram(protocol)) |
1078 | return SECCLASS_UDP_SOCKET; | |
1079 | else | |
1080 | return SECCLASS_RAWIP_SOCKET; | |
2ee92d46 JM |
1081 | case SOCK_DCCP: |
1082 | return SECCLASS_DCCP_SOCKET; | |
13402580 | 1083 | default: |
1da177e4 LT |
1084 | return SECCLASS_RAWIP_SOCKET; |
1085 | } | |
1086 | break; | |
1087 | case PF_NETLINK: | |
1088 | switch (protocol) { | |
1089 | case NETLINK_ROUTE: | |
1090 | return SECCLASS_NETLINK_ROUTE_SOCKET; | |
1091 | case NETLINK_FIREWALL: | |
1092 | return SECCLASS_NETLINK_FIREWALL_SOCKET; | |
216efaaa | 1093 | case NETLINK_INET_DIAG: |
1da177e4 LT |
1094 | return SECCLASS_NETLINK_TCPDIAG_SOCKET; |
1095 | case NETLINK_NFLOG: | |
1096 | return SECCLASS_NETLINK_NFLOG_SOCKET; | |
1097 | case NETLINK_XFRM: | |
1098 | return SECCLASS_NETLINK_XFRM_SOCKET; | |
1099 | case NETLINK_SELINUX: | |
1100 | return SECCLASS_NETLINK_SELINUX_SOCKET; | |
1101 | case NETLINK_AUDIT: | |
1102 | return SECCLASS_NETLINK_AUDIT_SOCKET; | |
1103 | case NETLINK_IP6_FW: | |
1104 | return SECCLASS_NETLINK_IP6FW_SOCKET; | |
1105 | case NETLINK_DNRTMSG: | |
1106 | return SECCLASS_NETLINK_DNRT_SOCKET; | |
0c9b7942 JM |
1107 | case NETLINK_KOBJECT_UEVENT: |
1108 | return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; | |
1da177e4 LT |
1109 | default: |
1110 | return SECCLASS_NETLINK_SOCKET; | |
1111 | } | |
1112 | case PF_PACKET: | |
1113 | return SECCLASS_PACKET_SOCKET; | |
1114 | case PF_KEY: | |
1115 | return SECCLASS_KEY_SOCKET; | |
3e3ff15e CP |
1116 | case PF_APPLETALK: |
1117 | return SECCLASS_APPLETALK_SOCKET; | |
1da177e4 LT |
1118 | } |
1119 | ||
1120 | return SECCLASS_SOCKET; | |
1121 | } | |
1122 | ||
1123 | #ifdef CONFIG_PROC_FS | |
8e6c9693 | 1124 | static int selinux_proc_get_sid(struct dentry *dentry, |
1da177e4 LT |
1125 | u16 tclass, |
1126 | u32 *sid) | |
1127 | { | |
8e6c9693 LAG |
1128 | int rc; |
1129 | char *buffer, *path; | |
1da177e4 | 1130 | |
828dfe1d | 1131 | buffer = (char *)__get_free_page(GFP_KERNEL); |
1da177e4 LT |
1132 | if (!buffer) |
1133 | return -ENOMEM; | |
1134 | ||
8e6c9693 LAG |
1135 | path = dentry_path_raw(dentry, buffer, PAGE_SIZE); |
1136 | if (IS_ERR(path)) | |
1137 | rc = PTR_ERR(path); | |
1138 | else { | |
1139 | /* each process gets a /proc/PID/ entry. Strip off the | |
1140 | * PID part to get a valid selinux labeling. | |
1141 | * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ | |
1142 | while (path[1] >= '0' && path[1] <= '9') { | |
1143 | path[1] = '/'; | |
1144 | path++; | |
1145 | } | |
1146 | rc = security_genfs_sid("proc", path, tclass, sid); | |
1da177e4 | 1147 | } |
1da177e4 LT |
1148 | free_page((unsigned long)buffer); |
1149 | return rc; | |
1150 | } | |
1151 | #else | |
8e6c9693 | 1152 | static int selinux_proc_get_sid(struct dentry *dentry, |
1da177e4 LT |
1153 | u16 tclass, |
1154 | u32 *sid) | |
1155 | { | |
1156 | return -EINVAL; | |
1157 | } | |
1158 | #endif | |
1159 | ||
1160 | /* The inode's security attributes must be initialized before first use. */ | |
1161 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) | |
1162 | { | |
1163 | struct superblock_security_struct *sbsec = NULL; | |
1164 | struct inode_security_struct *isec = inode->i_security; | |
1165 | u32 sid; | |
1166 | struct dentry *dentry; | |
1167 | #define INITCONTEXTLEN 255 | |
1168 | char *context = NULL; | |
1169 | unsigned len = 0; | |
1170 | int rc = 0; | |
1da177e4 LT |
1171 | |
1172 | if (isec->initialized) | |
1173 | goto out; | |
1174 | ||
23970741 | 1175 | mutex_lock(&isec->lock); |
1da177e4 | 1176 | if (isec->initialized) |
23970741 | 1177 | goto out_unlock; |
1da177e4 LT |
1178 | |
1179 | sbsec = inode->i_sb->s_security; | |
0d90a7ec | 1180 | if (!(sbsec->flags & SE_SBINITIALIZED)) { |
1da177e4 LT |
1181 | /* Defer initialization until selinux_complete_init, |
1182 | after the initial policy is loaded and the security | |
1183 | server is ready to handle calls. */ | |
1184 | spin_lock(&sbsec->isec_lock); | |
1185 | if (list_empty(&isec->list)) | |
1186 | list_add(&isec->list, &sbsec->isec_head); | |
1187 | spin_unlock(&sbsec->isec_lock); | |
23970741 | 1188 | goto out_unlock; |
1da177e4 LT |
1189 | } |
1190 | ||
1191 | switch (sbsec->behavior) { | |
1192 | case SECURITY_FS_USE_XATTR: | |
1193 | if (!inode->i_op->getxattr) { | |
1194 | isec->sid = sbsec->def_sid; | |
1195 | break; | |
1196 | } | |
1197 | ||
1198 | /* Need a dentry, since the xattr API requires one. | |
1199 | Life would be simpler if we could just pass the inode. */ | |
1200 | if (opt_dentry) { | |
1201 | /* Called from d_instantiate or d_splice_alias. */ | |
1202 | dentry = dget(opt_dentry); | |
1203 | } else { | |
1204 | /* Called from selinux_complete_init, try to find a dentry. */ | |
1205 | dentry = d_find_alias(inode); | |
1206 | } | |
1207 | if (!dentry) { | |
df7f54c0 EP |
1208 | /* |
1209 | * this is can be hit on boot when a file is accessed | |
1210 | * before the policy is loaded. When we load policy we | |
1211 | * may find inodes that have no dentry on the | |
1212 | * sbsec->isec_head list. No reason to complain as these | |
1213 | * will get fixed up the next time we go through | |
1214 | * inode_doinit with a dentry, before these inodes could | |
1215 | * be used again by userspace. | |
1216 | */ | |
23970741 | 1217 | goto out_unlock; |
1da177e4 LT |
1218 | } |
1219 | ||
1220 | len = INITCONTEXTLEN; | |
4cb912f1 | 1221 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1222 | if (!context) { |
1223 | rc = -ENOMEM; | |
1224 | dput(dentry); | |
23970741 | 1225 | goto out_unlock; |
1da177e4 | 1226 | } |
4cb912f1 | 1227 | context[len] = '\0'; |
1da177e4 LT |
1228 | rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, |
1229 | context, len); | |
1230 | if (rc == -ERANGE) { | |
314dabb8 JM |
1231 | kfree(context); |
1232 | ||
1da177e4 LT |
1233 | /* Need a larger buffer. Query for the right size. */ |
1234 | rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, | |
1235 | NULL, 0); | |
1236 | if (rc < 0) { | |
1237 | dput(dentry); | |
23970741 | 1238 | goto out_unlock; |
1da177e4 | 1239 | } |
1da177e4 | 1240 | len = rc; |
4cb912f1 | 1241 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1242 | if (!context) { |
1243 | rc = -ENOMEM; | |
1244 | dput(dentry); | |
23970741 | 1245 | goto out_unlock; |
1da177e4 | 1246 | } |
4cb912f1 | 1247 | context[len] = '\0'; |
1da177e4 LT |
1248 | rc = inode->i_op->getxattr(dentry, |
1249 | XATTR_NAME_SELINUX, | |
1250 | context, len); | |
1251 | } | |
1252 | dput(dentry); | |
1253 | if (rc < 0) { | |
1254 | if (rc != -ENODATA) { | |
744ba35e | 1255 | printk(KERN_WARNING "SELinux: %s: getxattr returned " |
dd6f953a | 1256 | "%d for dev=%s ino=%ld\n", __func__, |
1da177e4 LT |
1257 | -rc, inode->i_sb->s_id, inode->i_ino); |
1258 | kfree(context); | |
23970741 | 1259 | goto out_unlock; |
1da177e4 LT |
1260 | } |
1261 | /* Map ENODATA to the default file SID */ | |
1262 | sid = sbsec->def_sid; | |
1263 | rc = 0; | |
1264 | } else { | |
f5c1d5b2 | 1265 | rc = security_context_to_sid_default(context, rc, &sid, |
869ab514 SS |
1266 | sbsec->def_sid, |
1267 | GFP_NOFS); | |
1da177e4 | 1268 | if (rc) { |
4ba0a8ad EP |
1269 | char *dev = inode->i_sb->s_id; |
1270 | unsigned long ino = inode->i_ino; | |
1271 | ||
1272 | if (rc == -EINVAL) { | |
1273 | if (printk_ratelimit()) | |
1274 | printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " | |
1275 | "context=%s. This indicates you may need to relabel the inode or the " | |
1276 | "filesystem in question.\n", ino, dev, context); | |
1277 | } else { | |
1278 | printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " | |
1279 | "returned %d for dev=%s ino=%ld\n", | |
1280 | __func__, context, -rc, dev, ino); | |
1281 | } | |
1da177e4 LT |
1282 | kfree(context); |
1283 | /* Leave with the unlabeled SID */ | |
1284 | rc = 0; | |
1285 | break; | |
1286 | } | |
1287 | } | |
1288 | kfree(context); | |
1289 | isec->sid = sid; | |
1290 | break; | |
1291 | case SECURITY_FS_USE_TASK: | |
1292 | isec->sid = isec->task_sid; | |
1293 | break; | |
1294 | case SECURITY_FS_USE_TRANS: | |
1295 | /* Default to the fs SID. */ | |
1296 | isec->sid = sbsec->sid; | |
1297 | ||
1298 | /* Try to obtain a transition SID. */ | |
1299 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
652bb9b0 EP |
1300 | rc = security_transition_sid(isec->task_sid, sbsec->sid, |
1301 | isec->sclass, NULL, &sid); | |
1da177e4 | 1302 | if (rc) |
23970741 | 1303 | goto out_unlock; |
1da177e4 LT |
1304 | isec->sid = sid; |
1305 | break; | |
c312feb2 EP |
1306 | case SECURITY_FS_USE_MNTPOINT: |
1307 | isec->sid = sbsec->mntpoint_sid; | |
1308 | break; | |
1da177e4 | 1309 | default: |
c312feb2 | 1310 | /* Default to the fs superblock SID. */ |
1da177e4 LT |
1311 | isec->sid = sbsec->sid; |
1312 | ||
0d90a7ec | 1313 | if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) { |
8e6c9693 | 1314 | if (opt_dentry) { |
1da177e4 | 1315 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
8e6c9693 | 1316 | rc = selinux_proc_get_sid(opt_dentry, |
1da177e4 LT |
1317 | isec->sclass, |
1318 | &sid); | |
1319 | if (rc) | |
23970741 | 1320 | goto out_unlock; |
1da177e4 LT |
1321 | isec->sid = sid; |
1322 | } | |
1323 | } | |
1324 | break; | |
1325 | } | |
1326 | ||
1327 | isec->initialized = 1; | |
1328 | ||
23970741 EP |
1329 | out_unlock: |
1330 | mutex_unlock(&isec->lock); | |
1da177e4 LT |
1331 | out: |
1332 | if (isec->sclass == SECCLASS_FILE) | |
1333 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
1da177e4 LT |
1334 | return rc; |
1335 | } | |
1336 | ||
1337 | /* Convert a Linux signal to an access vector. */ | |
1338 | static inline u32 signal_to_av(int sig) | |
1339 | { | |
1340 | u32 perm = 0; | |
1341 | ||
1342 | switch (sig) { | |
1343 | case SIGCHLD: | |
1344 | /* Commonly granted from child to parent. */ | |
1345 | perm = PROCESS__SIGCHLD; | |
1346 | break; | |
1347 | case SIGKILL: | |
1348 | /* Cannot be caught or ignored */ | |
1349 | perm = PROCESS__SIGKILL; | |
1350 | break; | |
1351 | case SIGSTOP: | |
1352 | /* Cannot be caught or ignored */ | |
1353 | perm = PROCESS__SIGSTOP; | |
1354 | break; | |
1355 | default: | |
1356 | /* All other signals. */ | |
1357 | perm = PROCESS__SIGNAL; | |
1358 | break; | |
1359 | } | |
1360 | ||
1361 | return perm; | |
1362 | } | |
1363 | ||
d84f4f99 DH |
1364 | /* |
1365 | * Check permission between a pair of credentials | |
1366 | * fork check, ptrace check, etc. | |
1367 | */ | |
1368 | static int cred_has_perm(const struct cred *actor, | |
1369 | const struct cred *target, | |
1370 | u32 perms) | |
1371 | { | |
1372 | u32 asid = cred_sid(actor), tsid = cred_sid(target); | |
1373 | ||
1374 | return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL); | |
1375 | } | |
1376 | ||
275bb41e | 1377 | /* |
88e67f3b | 1378 | * Check permission between a pair of tasks, e.g. signal checks, |
275bb41e DH |
1379 | * fork check, ptrace check, etc. |
1380 | * tsk1 is the actor and tsk2 is the target | |
3b11a1de | 1381 | * - this uses the default subjective creds of tsk1 |
275bb41e DH |
1382 | */ |
1383 | static int task_has_perm(const struct task_struct *tsk1, | |
1384 | const struct task_struct *tsk2, | |
1da177e4 LT |
1385 | u32 perms) |
1386 | { | |
275bb41e DH |
1387 | const struct task_security_struct *__tsec1, *__tsec2; |
1388 | u32 sid1, sid2; | |
1da177e4 | 1389 | |
275bb41e DH |
1390 | rcu_read_lock(); |
1391 | __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid; | |
1392 | __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid; | |
1393 | rcu_read_unlock(); | |
1394 | return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL); | |
1da177e4 LT |
1395 | } |
1396 | ||
3b11a1de DH |
1397 | /* |
1398 | * Check permission between current and another task, e.g. signal checks, | |
1399 | * fork check, ptrace check, etc. | |
1400 | * current is the actor and tsk2 is the target | |
1401 | * - this uses current's subjective creds | |
1402 | */ | |
1403 | static int current_has_perm(const struct task_struct *tsk, | |
1404 | u32 perms) | |
1405 | { | |
1406 | u32 sid, tsid; | |
1407 | ||
1408 | sid = current_sid(); | |
1409 | tsid = task_sid(tsk); | |
1410 | return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL); | |
1411 | } | |
1412 | ||
b68e418c SS |
1413 | #if CAP_LAST_CAP > 63 |
1414 | #error Fix SELinux to handle capabilities > 63. | |
1415 | #endif | |
1416 | ||
1da177e4 LT |
1417 | /* Check whether a task is allowed to use a capability. */ |
1418 | static int task_has_capability(struct task_struct *tsk, | |
3699c53c | 1419 | const struct cred *cred, |
06112163 | 1420 | int cap, int audit) |
1da177e4 | 1421 | { |
2bf49690 | 1422 | struct common_audit_data ad; |
06112163 | 1423 | struct av_decision avd; |
b68e418c | 1424 | u16 sclass; |
3699c53c | 1425 | u32 sid = cred_sid(cred); |
b68e418c | 1426 | u32 av = CAP_TO_MASK(cap); |
06112163 | 1427 | int rc; |
1da177e4 | 1428 | |
2bf49690 | 1429 | COMMON_AUDIT_DATA_INIT(&ad, CAP); |
1da177e4 LT |
1430 | ad.tsk = tsk; |
1431 | ad.u.cap = cap; | |
1432 | ||
b68e418c SS |
1433 | switch (CAP_TO_INDEX(cap)) { |
1434 | case 0: | |
1435 | sclass = SECCLASS_CAPABILITY; | |
1436 | break; | |
1437 | case 1: | |
1438 | sclass = SECCLASS_CAPABILITY2; | |
1439 | break; | |
1440 | default: | |
1441 | printk(KERN_ERR | |
1442 | "SELinux: out of range capability %d\n", cap); | |
1443 | BUG(); | |
a35c6c83 | 1444 | return -EINVAL; |
b68e418c | 1445 | } |
06112163 | 1446 | |
275bb41e | 1447 | rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); |
9ade0cf4 EP |
1448 | if (audit == SECURITY_CAP_AUDIT) { |
1449 | int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0); | |
1450 | if (rc2) | |
1451 | return rc2; | |
1452 | } | |
06112163 | 1453 | return rc; |
1da177e4 LT |
1454 | } |
1455 | ||
1456 | /* Check whether a task is allowed to use a system operation. */ | |
1457 | static int task_has_system(struct task_struct *tsk, | |
1458 | u32 perms) | |
1459 | { | |
275bb41e | 1460 | u32 sid = task_sid(tsk); |
1da177e4 | 1461 | |
275bb41e | 1462 | return avc_has_perm(sid, SECINITSID_KERNEL, |
1da177e4 LT |
1463 | SECCLASS_SYSTEM, perms, NULL); |
1464 | } | |
1465 | ||
1466 | /* Check whether a task has a particular permission to an inode. | |
1467 | The 'adp' parameter is optional and allows other audit | |
1468 | data to be passed (e.g. the dentry). */ | |
88e67f3b | 1469 | static int inode_has_perm(const struct cred *cred, |
1da177e4 LT |
1470 | struct inode *inode, |
1471 | u32 perms, | |
9ade0cf4 EP |
1472 | struct common_audit_data *adp, |
1473 | unsigned flags) | |
1da177e4 | 1474 | { |
1da177e4 | 1475 | struct inode_security_struct *isec; |
275bb41e | 1476 | u32 sid; |
1da177e4 | 1477 | |
e0e81739 DH |
1478 | validate_creds(cred); |
1479 | ||
828dfe1d | 1480 | if (unlikely(IS_PRIVATE(inode))) |
bbaca6c2 SS |
1481 | return 0; |
1482 | ||
88e67f3b | 1483 | sid = cred_sid(cred); |
1da177e4 LT |
1484 | isec = inode->i_security; |
1485 | ||
9ade0cf4 | 1486 | return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags); |
1da177e4 LT |
1487 | } |
1488 | ||
95f4efb2 LT |
1489 | static int inode_has_perm_noadp(const struct cred *cred, |
1490 | struct inode *inode, | |
1491 | u32 perms, | |
1492 | unsigned flags) | |
1493 | { | |
1494 | struct common_audit_data ad; | |
1495 | ||
1496 | COMMON_AUDIT_DATA_INIT(&ad, INODE); | |
1497 | ad.u.inode = inode; | |
1498 | return inode_has_perm(cred, inode, perms, &ad, flags); | |
1499 | } | |
1500 | ||
1da177e4 LT |
1501 | /* Same as inode_has_perm, but pass explicit audit data containing |
1502 | the dentry to help the auditing code to more easily generate the | |
1503 | pathname if needed. */ | |
88e67f3b | 1504 | static inline int dentry_has_perm(const struct cred *cred, |
1da177e4 LT |
1505 | struct dentry *dentry, |
1506 | u32 av) | |
1507 | { | |
1508 | struct inode *inode = dentry->d_inode; | |
2bf49690 | 1509 | struct common_audit_data ad; |
88e67f3b | 1510 | |
2875fa00 EP |
1511 | COMMON_AUDIT_DATA_INIT(&ad, DENTRY); |
1512 | ad.u.dentry = dentry; | |
1513 | return inode_has_perm(cred, inode, av, &ad, 0); | |
1514 | } | |
1515 | ||
1516 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1517 | the path to help the auditing code to more easily generate the | |
1518 | pathname if needed. */ | |
1519 | static inline int path_has_perm(const struct cred *cred, | |
1520 | struct path *path, | |
1521 | u32 av) | |
1522 | { | |
1523 | struct inode *inode = path->dentry->d_inode; | |
1524 | struct common_audit_data ad; | |
1525 | ||
f48b7399 | 1526 | COMMON_AUDIT_DATA_INIT(&ad, PATH); |
2875fa00 | 1527 | ad.u.path = *path; |
9ade0cf4 | 1528 | return inode_has_perm(cred, inode, av, &ad, 0); |
1da177e4 LT |
1529 | } |
1530 | ||
1531 | /* Check whether a task can use an open file descriptor to | |
1532 | access an inode in a given way. Check access to the | |
1533 | descriptor itself, and then use dentry_has_perm to | |
1534 | check a particular permission to the file. | |
1535 | Access to the descriptor is implicitly granted if it | |
1536 | has the same SID as the process. If av is zero, then | |
1537 | access to the file is not checked, e.g. for cases | |
1538 | where only the descriptor is affected like seek. */ | |
88e67f3b DH |
1539 | static int file_has_perm(const struct cred *cred, |
1540 | struct file *file, | |
1541 | u32 av) | |
1da177e4 | 1542 | { |
1da177e4 | 1543 | struct file_security_struct *fsec = file->f_security; |
44707fdf | 1544 | struct inode *inode = file->f_path.dentry->d_inode; |
2bf49690 | 1545 | struct common_audit_data ad; |
88e67f3b | 1546 | u32 sid = cred_sid(cred); |
1da177e4 LT |
1547 | int rc; |
1548 | ||
f48b7399 EP |
1549 | COMMON_AUDIT_DATA_INIT(&ad, PATH); |
1550 | ad.u.path = file->f_path; | |
1da177e4 | 1551 | |
275bb41e DH |
1552 | if (sid != fsec->sid) { |
1553 | rc = avc_has_perm(sid, fsec->sid, | |
1da177e4 LT |
1554 | SECCLASS_FD, |
1555 | FD__USE, | |
1556 | &ad); | |
1557 | if (rc) | |
88e67f3b | 1558 | goto out; |
1da177e4 LT |
1559 | } |
1560 | ||
1561 | /* av is zero if only checking access to the descriptor. */ | |
88e67f3b | 1562 | rc = 0; |
1da177e4 | 1563 | if (av) |
9ade0cf4 | 1564 | rc = inode_has_perm(cred, inode, av, &ad, 0); |
1da177e4 | 1565 | |
88e67f3b DH |
1566 | out: |
1567 | return rc; | |
1da177e4 LT |
1568 | } |
1569 | ||
1570 | /* Check whether a task can create a file. */ | |
1571 | static int may_create(struct inode *dir, | |
1572 | struct dentry *dentry, | |
1573 | u16 tclass) | |
1574 | { | |
5fb49870 | 1575 | const struct task_security_struct *tsec = current_security(); |
1da177e4 LT |
1576 | struct inode_security_struct *dsec; |
1577 | struct superblock_security_struct *sbsec; | |
275bb41e | 1578 | u32 sid, newsid; |
2bf49690 | 1579 | struct common_audit_data ad; |
1da177e4 LT |
1580 | int rc; |
1581 | ||
1da177e4 LT |
1582 | dsec = dir->i_security; |
1583 | sbsec = dir->i_sb->s_security; | |
1584 | ||
275bb41e DH |
1585 | sid = tsec->sid; |
1586 | newsid = tsec->create_sid; | |
1587 | ||
a269434d EP |
1588 | COMMON_AUDIT_DATA_INIT(&ad, DENTRY); |
1589 | ad.u.dentry = dentry; | |
1da177e4 | 1590 | |
275bb41e | 1591 | rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, |
1da177e4 LT |
1592 | DIR__ADD_NAME | DIR__SEARCH, |
1593 | &ad); | |
1594 | if (rc) | |
1595 | return rc; | |
1596 | ||
cd89596f | 1597 | if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { |
cb1e922f EP |
1598 | rc = security_transition_sid(sid, dsec->sid, tclass, |
1599 | &dentry->d_name, &newsid); | |
1da177e4 LT |
1600 | if (rc) |
1601 | return rc; | |
1602 | } | |
1603 | ||
275bb41e | 1604 | rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); |
1da177e4 LT |
1605 | if (rc) |
1606 | return rc; | |
1607 | ||
1608 | return avc_has_perm(newsid, sbsec->sid, | |
1609 | SECCLASS_FILESYSTEM, | |
1610 | FILESYSTEM__ASSOCIATE, &ad); | |
1611 | } | |
1612 | ||
4eb582cf ML |
1613 | /* Check whether a task can create a key. */ |
1614 | static int may_create_key(u32 ksid, | |
1615 | struct task_struct *ctx) | |
1616 | { | |
275bb41e | 1617 | u32 sid = task_sid(ctx); |
4eb582cf | 1618 | |
275bb41e | 1619 | return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL); |
4eb582cf ML |
1620 | } |
1621 | ||
828dfe1d EP |
1622 | #define MAY_LINK 0 |
1623 | #define MAY_UNLINK 1 | |
1624 | #define MAY_RMDIR 2 | |
1da177e4 LT |
1625 | |
1626 | /* Check whether a task can link, unlink, or rmdir a file/directory. */ | |
1627 | static int may_link(struct inode *dir, | |
1628 | struct dentry *dentry, | |
1629 | int kind) | |
1630 | ||
1631 | { | |
1da177e4 | 1632 | struct inode_security_struct *dsec, *isec; |
2bf49690 | 1633 | struct common_audit_data ad; |
275bb41e | 1634 | u32 sid = current_sid(); |
1da177e4 LT |
1635 | u32 av; |
1636 | int rc; | |
1637 | ||
1da177e4 LT |
1638 | dsec = dir->i_security; |
1639 | isec = dentry->d_inode->i_security; | |
1640 | ||
a269434d EP |
1641 | COMMON_AUDIT_DATA_INIT(&ad, DENTRY); |
1642 | ad.u.dentry = dentry; | |
1da177e4 LT |
1643 | |
1644 | av = DIR__SEARCH; | |
1645 | av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); | |
275bb41e | 1646 | rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); |
1da177e4 LT |
1647 | if (rc) |
1648 | return rc; | |
1649 | ||
1650 | switch (kind) { | |
1651 | case MAY_LINK: | |
1652 | av = FILE__LINK; | |
1653 | break; | |
1654 | case MAY_UNLINK: | |
1655 | av = FILE__UNLINK; | |
1656 | break; | |
1657 | case MAY_RMDIR: | |
1658 | av = DIR__RMDIR; | |
1659 | break; | |
1660 | default: | |
744ba35e EP |
1661 | printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", |
1662 | __func__, kind); | |
1da177e4 LT |
1663 | return 0; |
1664 | } | |
1665 | ||
275bb41e | 1666 | rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); |
1da177e4 LT |
1667 | return rc; |
1668 | } | |
1669 | ||
1670 | static inline int may_rename(struct inode *old_dir, | |
1671 | struct dentry *old_dentry, | |
1672 | struct inode *new_dir, | |
1673 | struct dentry *new_dentry) | |
1674 | { | |
1da177e4 | 1675 | struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; |
2bf49690 | 1676 | struct common_audit_data ad; |
275bb41e | 1677 | u32 sid = current_sid(); |
1da177e4 LT |
1678 | u32 av; |
1679 | int old_is_dir, new_is_dir; | |
1680 | int rc; | |
1681 | ||
1da177e4 LT |
1682 | old_dsec = old_dir->i_security; |
1683 | old_isec = old_dentry->d_inode->i_security; | |
1684 | old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); | |
1685 | new_dsec = new_dir->i_security; | |
1686 | ||
a269434d | 1687 | COMMON_AUDIT_DATA_INIT(&ad, DENTRY); |
1da177e4 | 1688 | |
a269434d | 1689 | ad.u.dentry = old_dentry; |
275bb41e | 1690 | rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, |
1da177e4 LT |
1691 | DIR__REMOVE_NAME | DIR__SEARCH, &ad); |
1692 | if (rc) | |
1693 | return rc; | |
275bb41e | 1694 | rc = avc_has_perm(sid, old_isec->sid, |
1da177e4 LT |
1695 | old_isec->sclass, FILE__RENAME, &ad); |
1696 | if (rc) | |
1697 | return rc; | |
1698 | if (old_is_dir && new_dir != old_dir) { | |
275bb41e | 1699 | rc = avc_has_perm(sid, old_isec->sid, |
1da177e4 LT |
1700 | old_isec->sclass, DIR__REPARENT, &ad); |
1701 | if (rc) | |
1702 | return rc; | |
1703 | } | |
1704 | ||
a269434d | 1705 | ad.u.dentry = new_dentry; |
1da177e4 LT |
1706 | av = DIR__ADD_NAME | DIR__SEARCH; |
1707 | if (new_dentry->d_inode) | |
1708 | av |= DIR__REMOVE_NAME; | |
275bb41e | 1709 | rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); |
1da177e4 LT |
1710 | if (rc) |
1711 | return rc; | |
1712 | if (new_dentry->d_inode) { | |
1713 | new_isec = new_dentry->d_inode->i_security; | |
1714 | new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); | |
275bb41e | 1715 | rc = avc_has_perm(sid, new_isec->sid, |
1da177e4 LT |
1716 | new_isec->sclass, |
1717 | (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); | |
1718 | if (rc) | |
1719 | return rc; | |
1720 | } | |
1721 | ||
1722 | return 0; | |
1723 | } | |
1724 | ||
1725 | /* Check whether a task can perform a filesystem operation. */ | |
88e67f3b | 1726 | static int superblock_has_perm(const struct cred *cred, |
1da177e4 LT |
1727 | struct super_block *sb, |
1728 | u32 perms, | |
2bf49690 | 1729 | struct common_audit_data *ad) |
1da177e4 | 1730 | { |
1da177e4 | 1731 | struct superblock_security_struct *sbsec; |
88e67f3b | 1732 | u32 sid = cred_sid(cred); |
1da177e4 | 1733 | |
1da177e4 | 1734 | sbsec = sb->s_security; |
275bb41e | 1735 | return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); |
1da177e4 LT |
1736 | } |
1737 | ||
1738 | /* Convert a Linux mode and permission mask to an access vector. */ | |
1739 | static inline u32 file_mask_to_av(int mode, int mask) | |
1740 | { | |
1741 | u32 av = 0; | |
1742 | ||
1743 | if ((mode & S_IFMT) != S_IFDIR) { | |
1744 | if (mask & MAY_EXEC) | |
1745 | av |= FILE__EXECUTE; | |
1746 | if (mask & MAY_READ) | |
1747 | av |= FILE__READ; | |
1748 | ||
1749 | if (mask & MAY_APPEND) | |
1750 | av |= FILE__APPEND; | |
1751 | else if (mask & MAY_WRITE) | |
1752 | av |= FILE__WRITE; | |
1753 | ||
1754 | } else { | |
1755 | if (mask & MAY_EXEC) | |
1756 | av |= DIR__SEARCH; | |
1757 | if (mask & MAY_WRITE) | |
1758 | av |= DIR__WRITE; | |
1759 | if (mask & MAY_READ) | |
1760 | av |= DIR__READ; | |
1761 | } | |
1762 | ||
1763 | return av; | |
1764 | } | |
1765 | ||
8b6a5a37 EP |
1766 | /* Convert a Linux file to an access vector. */ |
1767 | static inline u32 file_to_av(struct file *file) | |
1768 | { | |
1769 | u32 av = 0; | |
1770 | ||
1771 | if (file->f_mode & FMODE_READ) | |
1772 | av |= FILE__READ; | |
1773 | if (file->f_mode & FMODE_WRITE) { | |
1774 | if (file->f_flags & O_APPEND) | |
1775 | av |= FILE__APPEND; | |
1776 | else | |
1777 | av |= FILE__WRITE; | |
1778 | } | |
1779 | if (!av) { | |
1780 | /* | |
1781 | * Special file opened with flags 3 for ioctl-only use. | |
1782 | */ | |
1783 | av = FILE__IOCTL; | |
1784 | } | |
1785 | ||
1786 | return av; | |
1787 | } | |
1788 | ||
b0c636b9 | 1789 | /* |
8b6a5a37 | 1790 | * Convert a file to an access vector and include the correct open |
b0c636b9 EP |
1791 | * open permission. |
1792 | */ | |
8b6a5a37 | 1793 | static inline u32 open_file_to_av(struct file *file) |
b0c636b9 | 1794 | { |
8b6a5a37 | 1795 | u32 av = file_to_av(file); |
b0c636b9 | 1796 | |
49b7b8de EP |
1797 | if (selinux_policycap_openperm) |
1798 | av |= FILE__OPEN; | |
1799 | ||
b0c636b9 EP |
1800 | return av; |
1801 | } | |
1802 | ||
1da177e4 LT |
1803 | /* Hook functions begin here. */ |
1804 | ||
9e48858f | 1805 | static int selinux_ptrace_access_check(struct task_struct *child, |
5cd9c58f | 1806 | unsigned int mode) |
1da177e4 | 1807 | { |
1da177e4 LT |
1808 | int rc; |
1809 | ||
9e48858f | 1810 | rc = cap_ptrace_access_check(child, mode); |
1da177e4 LT |
1811 | if (rc) |
1812 | return rc; | |
1813 | ||
006ebb40 | 1814 | if (mode == PTRACE_MODE_READ) { |
275bb41e DH |
1815 | u32 sid = current_sid(); |
1816 | u32 csid = task_sid(child); | |
1817 | return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); | |
006ebb40 SS |
1818 | } |
1819 | ||
3b11a1de | 1820 | return current_has_perm(child, PROCESS__PTRACE); |
5cd9c58f DH |
1821 | } |
1822 | ||
1823 | static int selinux_ptrace_traceme(struct task_struct *parent) | |
1824 | { | |
1825 | int rc; | |
1826 | ||
200ac532 | 1827 | rc = cap_ptrace_traceme(parent); |
5cd9c58f DH |
1828 | if (rc) |
1829 | return rc; | |
1830 | ||
1831 | return task_has_perm(parent, current, PROCESS__PTRACE); | |
1da177e4 LT |
1832 | } |
1833 | ||
1834 | static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, | |
828dfe1d | 1835 | kernel_cap_t *inheritable, kernel_cap_t *permitted) |
1da177e4 LT |
1836 | { |
1837 | int error; | |
1838 | ||
3b11a1de | 1839 | error = current_has_perm(target, PROCESS__GETCAP); |
1da177e4 LT |
1840 | if (error) |
1841 | return error; | |
1842 | ||
200ac532 | 1843 | return cap_capget(target, effective, inheritable, permitted); |
1da177e4 LT |
1844 | } |
1845 | ||
d84f4f99 DH |
1846 | static int selinux_capset(struct cred *new, const struct cred *old, |
1847 | const kernel_cap_t *effective, | |
1848 | const kernel_cap_t *inheritable, | |
1849 | const kernel_cap_t *permitted) | |
1da177e4 LT |
1850 | { |
1851 | int error; | |
1852 | ||
200ac532 | 1853 | error = cap_capset(new, old, |
d84f4f99 | 1854 | effective, inheritable, permitted); |
1da177e4 LT |
1855 | if (error) |
1856 | return error; | |
1857 | ||
d84f4f99 | 1858 | return cred_has_perm(old, new, PROCESS__SETCAP); |
1da177e4 LT |
1859 | } |
1860 | ||
5626d3e8 JM |
1861 | /* |
1862 | * (This comment used to live with the selinux_task_setuid hook, | |
1863 | * which was removed). | |
1864 | * | |
1865 | * Since setuid only affects the current process, and since the SELinux | |
1866 | * controls are not based on the Linux identity attributes, SELinux does not | |
1867 | * need to control this operation. However, SELinux does control the use of | |
1868 | * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. | |
1869 | */ | |
1870 | ||
3699c53c | 1871 | static int selinux_capable(struct task_struct *tsk, const struct cred *cred, |
3486740a | 1872 | struct user_namespace *ns, int cap, int audit) |
1da177e4 LT |
1873 | { |
1874 | int rc; | |
1875 | ||
3486740a | 1876 | rc = cap_capable(tsk, cred, ns, cap, audit); |
1da177e4 LT |
1877 | if (rc) |
1878 | return rc; | |
1879 | ||
3699c53c | 1880 | return task_has_capability(tsk, cred, cap, audit); |
1da177e4 LT |
1881 | } |
1882 | ||
1da177e4 LT |
1883 | static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) |
1884 | { | |
88e67f3b | 1885 | const struct cred *cred = current_cred(); |
1da177e4 LT |
1886 | int rc = 0; |
1887 | ||
1888 | if (!sb) | |
1889 | return 0; | |
1890 | ||
1891 | switch (cmds) { | |
828dfe1d EP |
1892 | case Q_SYNC: |
1893 | case Q_QUOTAON: | |
1894 | case Q_QUOTAOFF: | |
1895 | case Q_SETINFO: | |
1896 | case Q_SETQUOTA: | |
88e67f3b | 1897 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); |
828dfe1d EP |
1898 | break; |
1899 | case Q_GETFMT: | |
1900 | case Q_GETINFO: | |
1901 | case Q_GETQUOTA: | |
88e67f3b | 1902 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); |
828dfe1d EP |
1903 | break; |
1904 | default: | |
1905 | rc = 0; /* let the kernel handle invalid cmds */ | |
1906 | break; | |
1da177e4 LT |
1907 | } |
1908 | return rc; | |
1909 | } | |
1910 | ||
1911 | static int selinux_quota_on(struct dentry *dentry) | |
1912 | { | |
88e67f3b DH |
1913 | const struct cred *cred = current_cred(); |
1914 | ||
2875fa00 | 1915 | return dentry_has_perm(cred, dentry, FILE__QUOTAON); |
1da177e4 LT |
1916 | } |
1917 | ||
12b3052c | 1918 | static int selinux_syslog(int type) |
1da177e4 LT |
1919 | { |
1920 | int rc; | |
1921 | ||
1da177e4 | 1922 | switch (type) { |
d78ca3cd KC |
1923 | case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ |
1924 | case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ | |
828dfe1d EP |
1925 | rc = task_has_system(current, SYSTEM__SYSLOG_READ); |
1926 | break; | |
d78ca3cd KC |
1927 | case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ |
1928 | case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ | |
1929 | /* Set level of messages printed to console */ | |
1930 | case SYSLOG_ACTION_CONSOLE_LEVEL: | |
828dfe1d EP |
1931 | rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE); |
1932 | break; | |
d78ca3cd KC |
1933 | case SYSLOG_ACTION_CLOSE: /* Close log */ |
1934 | case SYSLOG_ACTION_OPEN: /* Open log */ | |
1935 | case SYSLOG_ACTION_READ: /* Read from log */ | |
1936 | case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */ | |
1937 | case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */ | |
828dfe1d EP |
1938 | default: |
1939 | rc = task_has_system(current, SYSTEM__SYSLOG_MOD); | |
1940 | break; | |
1da177e4 LT |
1941 | } |
1942 | return rc; | |
1943 | } | |
1944 | ||
1945 | /* | |
1946 | * Check that a process has enough memory to allocate a new virtual | |
1947 | * mapping. 0 means there is enough memory for the allocation to | |
1948 | * succeed and -ENOMEM implies there is not. | |
1949 | * | |
1da177e4 LT |
1950 | * Do not audit the selinux permission check, as this is applied to all |
1951 | * processes that allocate mappings. | |
1952 | */ | |
34b4e4aa | 1953 | static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
1954 | { |
1955 | int rc, cap_sys_admin = 0; | |
1da177e4 | 1956 | |
3486740a SH |
1957 | rc = selinux_capable(current, current_cred(), |
1958 | &init_user_ns, CAP_SYS_ADMIN, | |
3699c53c | 1959 | SECURITY_CAP_NOAUDIT); |
1da177e4 LT |
1960 | if (rc == 0) |
1961 | cap_sys_admin = 1; | |
1962 | ||
34b4e4aa | 1963 | return __vm_enough_memory(mm, pages, cap_sys_admin); |
1da177e4 LT |
1964 | } |
1965 | ||
1966 | /* binprm security operations */ | |
1967 | ||
a6f76f23 | 1968 | static int selinux_bprm_set_creds(struct linux_binprm *bprm) |
1da177e4 | 1969 | { |
a6f76f23 DH |
1970 | const struct task_security_struct *old_tsec; |
1971 | struct task_security_struct *new_tsec; | |
1da177e4 | 1972 | struct inode_security_struct *isec; |
2bf49690 | 1973 | struct common_audit_data ad; |
a6f76f23 | 1974 | struct inode *inode = bprm->file->f_path.dentry->d_inode; |
1da177e4 LT |
1975 | int rc; |
1976 | ||
200ac532 | 1977 | rc = cap_bprm_set_creds(bprm); |
1da177e4 LT |
1978 | if (rc) |
1979 | return rc; | |
1980 | ||
a6f76f23 DH |
1981 | /* SELinux context only depends on initial program or script and not |
1982 | * the script interpreter */ | |
1983 | if (bprm->cred_prepared) | |
1da177e4 LT |
1984 | return 0; |
1985 | ||
a6f76f23 DH |
1986 | old_tsec = current_security(); |
1987 | new_tsec = bprm->cred->security; | |
1da177e4 LT |
1988 | isec = inode->i_security; |
1989 | ||
1990 | /* Default to the current task SID. */ | |
a6f76f23 DH |
1991 | new_tsec->sid = old_tsec->sid; |
1992 | new_tsec->osid = old_tsec->sid; | |
1da177e4 | 1993 | |
28eba5bf | 1994 | /* Reset fs, key, and sock SIDs on execve. */ |
a6f76f23 DH |
1995 | new_tsec->create_sid = 0; |
1996 | new_tsec->keycreate_sid = 0; | |
1997 | new_tsec->sockcreate_sid = 0; | |
1da177e4 | 1998 | |
a6f76f23 DH |
1999 | if (old_tsec->exec_sid) { |
2000 | new_tsec->sid = old_tsec->exec_sid; | |
1da177e4 | 2001 | /* Reset exec SID on execve. */ |
a6f76f23 | 2002 | new_tsec->exec_sid = 0; |
1da177e4 LT |
2003 | } else { |
2004 | /* Check for a default transition on this program. */ | |
a6f76f23 | 2005 | rc = security_transition_sid(old_tsec->sid, isec->sid, |
652bb9b0 EP |
2006 | SECCLASS_PROCESS, NULL, |
2007 | &new_tsec->sid); | |
1da177e4 LT |
2008 | if (rc) |
2009 | return rc; | |
2010 | } | |
2011 | ||
f48b7399 EP |
2012 | COMMON_AUDIT_DATA_INIT(&ad, PATH); |
2013 | ad.u.path = bprm->file->f_path; | |
1da177e4 | 2014 | |
3d5ff529 | 2015 | if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) |
a6f76f23 | 2016 | new_tsec->sid = old_tsec->sid; |
1da177e4 | 2017 | |
a6f76f23 DH |
2018 | if (new_tsec->sid == old_tsec->sid) { |
2019 | rc = avc_has_perm(old_tsec->sid, isec->sid, | |
1da177e4 LT |
2020 | SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); |
2021 | if (rc) | |
2022 | return rc; | |
2023 | } else { | |
2024 | /* Check permissions for the transition. */ | |
a6f76f23 | 2025 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, |
1da177e4 LT |
2026 | SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); |
2027 | if (rc) | |
2028 | return rc; | |
2029 | ||
a6f76f23 | 2030 | rc = avc_has_perm(new_tsec->sid, isec->sid, |
1da177e4 LT |
2031 | SECCLASS_FILE, FILE__ENTRYPOINT, &ad); |
2032 | if (rc) | |
2033 | return rc; | |
2034 | ||
a6f76f23 DH |
2035 | /* Check for shared state */ |
2036 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
2037 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, | |
2038 | SECCLASS_PROCESS, PROCESS__SHARE, | |
2039 | NULL); | |
2040 | if (rc) | |
2041 | return -EPERM; | |
2042 | } | |
2043 | ||
2044 | /* Make sure that anyone attempting to ptrace over a task that | |
2045 | * changes its SID has the appropriate permit */ | |
2046 | if (bprm->unsafe & | |
2047 | (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { | |
2048 | struct task_struct *tracer; | |
2049 | struct task_security_struct *sec; | |
2050 | u32 ptsid = 0; | |
2051 | ||
2052 | rcu_read_lock(); | |
06d98473 | 2053 | tracer = ptrace_parent(current); |
a6f76f23 DH |
2054 | if (likely(tracer != NULL)) { |
2055 | sec = __task_cred(tracer)->security; | |
2056 | ptsid = sec->sid; | |
2057 | } | |
2058 | rcu_read_unlock(); | |
2059 | ||
2060 | if (ptsid != 0) { | |
2061 | rc = avc_has_perm(ptsid, new_tsec->sid, | |
2062 | SECCLASS_PROCESS, | |
2063 | PROCESS__PTRACE, NULL); | |
2064 | if (rc) | |
2065 | return -EPERM; | |
2066 | } | |
2067 | } | |
1da177e4 | 2068 | |
a6f76f23 DH |
2069 | /* Clear any possibly unsafe personality bits on exec: */ |
2070 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
1da177e4 LT |
2071 | } |
2072 | ||
1da177e4 LT |
2073 | return 0; |
2074 | } | |
2075 | ||
828dfe1d | 2076 | static int selinux_bprm_secureexec(struct linux_binprm *bprm) |
1da177e4 | 2077 | { |
5fb49870 | 2078 | const struct task_security_struct *tsec = current_security(); |
275bb41e | 2079 | u32 sid, osid; |
1da177e4 LT |
2080 | int atsecure = 0; |
2081 | ||
275bb41e DH |
2082 | sid = tsec->sid; |
2083 | osid = tsec->osid; | |
2084 | ||
2085 | if (osid != sid) { | |
1da177e4 LT |
2086 | /* Enable secure mode for SIDs transitions unless |
2087 | the noatsecure permission is granted between | |
2088 | the two SIDs, i.e. ahp returns 0. */ | |
275bb41e | 2089 | atsecure = avc_has_perm(osid, sid, |
a6f76f23 DH |
2090 | SECCLASS_PROCESS, |
2091 | PROCESS__NOATSECURE, NULL); | |
1da177e4 LT |
2092 | } |
2093 | ||
200ac532 | 2094 | return (atsecure || cap_bprm_secureexec(bprm)); |
1da177e4 LT |
2095 | } |
2096 | ||
1da177e4 | 2097 | /* Derived from fs/exec.c:flush_old_files. */ |
745ca247 DH |
2098 | static inline void flush_unauthorized_files(const struct cred *cred, |
2099 | struct files_struct *files) | |
1da177e4 | 2100 | { |
2bf49690 | 2101 | struct common_audit_data ad; |
1da177e4 | 2102 | struct file *file, *devnull = NULL; |
b20c8122 | 2103 | struct tty_struct *tty; |
badf1662 | 2104 | struct fdtable *fdt; |
1da177e4 | 2105 | long j = -1; |
24ec839c | 2106 | int drop_tty = 0; |
1da177e4 | 2107 | |
24ec839c | 2108 | tty = get_current_tty(); |
1da177e4 | 2109 | if (tty) { |
ee2ffa0d | 2110 | spin_lock(&tty_files_lock); |
37dd0bd0 | 2111 | if (!list_empty(&tty->tty_files)) { |
d996b62a | 2112 | struct tty_file_private *file_priv; |
37dd0bd0 EP |
2113 | struct inode *inode; |
2114 | ||
1da177e4 LT |
2115 | /* Revalidate access to controlling tty. |
2116 | Use inode_has_perm on the tty inode directly rather | |
2117 | than using file_has_perm, as this particular open | |
2118 | file may belong to another process and we are only | |
2119 | interested in the inode-based check here. */ | |
d996b62a NP |
2120 | file_priv = list_first_entry(&tty->tty_files, |
2121 | struct tty_file_private, list); | |
2122 | file = file_priv->file; | |
37dd0bd0 | 2123 | inode = file->f_path.dentry->d_inode; |
95f4efb2 LT |
2124 | if (inode_has_perm_noadp(cred, inode, |
2125 | FILE__READ | FILE__WRITE, 0)) { | |
24ec839c | 2126 | drop_tty = 1; |
1da177e4 LT |
2127 | } |
2128 | } | |
ee2ffa0d | 2129 | spin_unlock(&tty_files_lock); |
452a00d2 | 2130 | tty_kref_put(tty); |
1da177e4 | 2131 | } |
98a27ba4 EB |
2132 | /* Reset controlling tty. */ |
2133 | if (drop_tty) | |
2134 | no_tty(); | |
1da177e4 LT |
2135 | |
2136 | /* Revalidate access to inherited open files. */ | |
2137 | ||
f48b7399 | 2138 | COMMON_AUDIT_DATA_INIT(&ad, INODE); |
1da177e4 LT |
2139 | |
2140 | spin_lock(&files->file_lock); | |
2141 | for (;;) { | |
2142 | unsigned long set, i; | |
2143 | int fd; | |
2144 | ||
2145 | j++; | |
2146 | i = j * __NFDBITS; | |
badf1662 | 2147 | fdt = files_fdtable(files); |
bbea9f69 | 2148 | if (i >= fdt->max_fds) |
1da177e4 | 2149 | break; |
badf1662 | 2150 | set = fdt->open_fds->fds_bits[j]; |
1da177e4 LT |
2151 | if (!set) |
2152 | continue; | |
2153 | spin_unlock(&files->file_lock); | |
828dfe1d | 2154 | for ( ; set ; i++, set >>= 1) { |
1da177e4 LT |
2155 | if (set & 1) { |
2156 | file = fget(i); | |
2157 | if (!file) | |
2158 | continue; | |
88e67f3b | 2159 | if (file_has_perm(cred, |
1da177e4 LT |
2160 | file, |
2161 | file_to_av(file))) { | |
2162 | sys_close(i); | |
2163 | fd = get_unused_fd(); | |
2164 | if (fd != i) { | |
2165 | if (fd >= 0) | |
2166 | put_unused_fd(fd); | |
2167 | fput(file); | |
2168 | continue; | |
2169 | } | |
2170 | if (devnull) { | |
095975da | 2171 | get_file(devnull); |
1da177e4 | 2172 | } else { |
745ca247 DH |
2173 | devnull = dentry_open( |
2174 | dget(selinux_null), | |
2175 | mntget(selinuxfs_mount), | |
2176 | O_RDWR, cred); | |
fc5d81e6 AM |
2177 | if (IS_ERR(devnull)) { |
2178 | devnull = NULL; | |
1da177e4 LT |
2179 | put_unused_fd(fd); |
2180 | fput(file); | |
2181 | continue; | |
2182 | } | |
2183 | } | |
2184 | fd_install(fd, devnull); | |
2185 | } | |
2186 | fput(file); | |
2187 | } | |
2188 | } | |
2189 | spin_lock(&files->file_lock); | |
2190 | ||
2191 | } | |
2192 | spin_unlock(&files->file_lock); | |
2193 | } | |
2194 | ||
a6f76f23 DH |
2195 | /* |
2196 | * Prepare a process for imminent new credential changes due to exec | |
2197 | */ | |
2198 | static void selinux_bprm_committing_creds(struct linux_binprm *bprm) | |
1da177e4 | 2199 | { |
a6f76f23 DH |
2200 | struct task_security_struct *new_tsec; |
2201 | struct rlimit *rlim, *initrlim; | |
2202 | int rc, i; | |
d84f4f99 | 2203 | |
a6f76f23 DH |
2204 | new_tsec = bprm->cred->security; |
2205 | if (new_tsec->sid == new_tsec->osid) | |
2206 | return; | |
1da177e4 | 2207 | |
a6f76f23 DH |
2208 | /* Close files for which the new task SID is not authorized. */ |
2209 | flush_unauthorized_files(bprm->cred, current->files); | |
0356357c | 2210 | |
a6f76f23 DH |
2211 | /* Always clear parent death signal on SID transitions. */ |
2212 | current->pdeath_signal = 0; | |
0356357c | 2213 | |
a6f76f23 DH |
2214 | /* Check whether the new SID can inherit resource limits from the old |
2215 | * SID. If not, reset all soft limits to the lower of the current | |
2216 | * task's hard limit and the init task's soft limit. | |
2217 | * | |
2218 | * Note that the setting of hard limits (even to lower them) can be | |
2219 | * controlled by the setrlimit check. The inclusion of the init task's | |
2220 | * soft limit into the computation is to avoid resetting soft limits | |
2221 | * higher than the default soft limit for cases where the default is | |
2222 | * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. | |
2223 | */ | |
2224 | rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, | |
2225 | PROCESS__RLIMITINH, NULL); | |
2226 | if (rc) { | |
eb2d55a3 ON |
2227 | /* protect against do_prlimit() */ |
2228 | task_lock(current); | |
a6f76f23 DH |
2229 | for (i = 0; i < RLIM_NLIMITS; i++) { |
2230 | rlim = current->signal->rlim + i; | |
2231 | initrlim = init_task.signal->rlim + i; | |
2232 | rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); | |
1da177e4 | 2233 | } |
eb2d55a3 ON |
2234 | task_unlock(current); |
2235 | update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); | |
1da177e4 LT |
2236 | } |
2237 | } | |
2238 | ||
2239 | /* | |
a6f76f23 DH |
2240 | * Clean up the process immediately after the installation of new credentials |
2241 | * due to exec | |
1da177e4 | 2242 | */ |
a6f76f23 | 2243 | static void selinux_bprm_committed_creds(struct linux_binprm *bprm) |
1da177e4 | 2244 | { |
a6f76f23 | 2245 | const struct task_security_struct *tsec = current_security(); |
1da177e4 | 2246 | struct itimerval itimer; |
a6f76f23 | 2247 | u32 osid, sid; |
1da177e4 LT |
2248 | int rc, i; |
2249 | ||
a6f76f23 DH |
2250 | osid = tsec->osid; |
2251 | sid = tsec->sid; | |
2252 | ||
2253 | if (sid == osid) | |
1da177e4 LT |
2254 | return; |
2255 | ||
a6f76f23 DH |
2256 | /* Check whether the new SID can inherit signal state from the old SID. |
2257 | * If not, clear itimers to avoid subsequent signal generation and | |
2258 | * flush and unblock signals. | |
2259 | * | |
2260 | * This must occur _after_ the task SID has been updated so that any | |
2261 | * kill done after the flush will be checked against the new SID. | |
2262 | */ | |
2263 | rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); | |
1da177e4 LT |
2264 | if (rc) { |
2265 | memset(&itimer, 0, sizeof itimer); | |
2266 | for (i = 0; i < 3; i++) | |
2267 | do_setitimer(i, &itimer, NULL); | |
1da177e4 | 2268 | spin_lock_irq(¤t->sighand->siglock); |
3bcac026 DH |
2269 | if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { |
2270 | __flush_signals(current); | |
2271 | flush_signal_handlers(current, 1); | |
2272 | sigemptyset(¤t->blocked); | |
2273 | } | |
1da177e4 LT |
2274 | spin_unlock_irq(¤t->sighand->siglock); |
2275 | } | |
2276 | ||
a6f76f23 DH |
2277 | /* Wake up the parent if it is waiting so that it can recheck |
2278 | * wait permission to the new task SID. */ | |
ecd6de3c | 2279 | read_lock(&tasklist_lock); |
0b7570e7 | 2280 | __wake_up_parent(current, current->real_parent); |
ecd6de3c | 2281 | read_unlock(&tasklist_lock); |
1da177e4 LT |
2282 | } |
2283 | ||
2284 | /* superblock security operations */ | |
2285 | ||
2286 | static int selinux_sb_alloc_security(struct super_block *sb) | |
2287 | { | |
2288 | return superblock_alloc_security(sb); | |
2289 | } | |
2290 | ||
2291 | static void selinux_sb_free_security(struct super_block *sb) | |
2292 | { | |
2293 | superblock_free_security(sb); | |
2294 | } | |
2295 | ||
2296 | static inline int match_prefix(char *prefix, int plen, char *option, int olen) | |
2297 | { | |
2298 | if (plen > olen) | |
2299 | return 0; | |
2300 | ||
2301 | return !memcmp(prefix, option, plen); | |
2302 | } | |
2303 | ||
2304 | static inline int selinux_option(char *option, int len) | |
2305 | { | |
832cbd9a EP |
2306 | return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || |
2307 | match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || | |
2308 | match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || | |
11689d47 DQ |
2309 | match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || |
2310 | match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); | |
1da177e4 LT |
2311 | } |
2312 | ||
2313 | static inline void take_option(char **to, char *from, int *first, int len) | |
2314 | { | |
2315 | if (!*first) { | |
2316 | **to = ','; | |
2317 | *to += 1; | |
3528a953 | 2318 | } else |
1da177e4 LT |
2319 | *first = 0; |
2320 | memcpy(*to, from, len); | |
2321 | *to += len; | |
2322 | } | |
2323 | ||
828dfe1d EP |
2324 | static inline void take_selinux_option(char **to, char *from, int *first, |
2325 | int len) | |
3528a953 CO |
2326 | { |
2327 | int current_size = 0; | |
2328 | ||
2329 | if (!*first) { | |
2330 | **to = '|'; | |
2331 | *to += 1; | |
828dfe1d | 2332 | } else |
3528a953 CO |
2333 | *first = 0; |
2334 | ||
2335 | while (current_size < len) { | |
2336 | if (*from != '"') { | |
2337 | **to = *from; | |
2338 | *to += 1; | |
2339 | } | |
2340 | from += 1; | |
2341 | current_size += 1; | |
2342 | } | |
2343 | } | |
2344 | ||
e0007529 | 2345 | static int selinux_sb_copy_data(char *orig, char *copy) |
1da177e4 LT |
2346 | { |
2347 | int fnosec, fsec, rc = 0; | |
2348 | char *in_save, *in_curr, *in_end; | |
2349 | char *sec_curr, *nosec_save, *nosec; | |
3528a953 | 2350 | int open_quote = 0; |
1da177e4 LT |
2351 | |
2352 | in_curr = orig; | |
2353 | sec_curr = copy; | |
2354 | ||
1da177e4 LT |
2355 | nosec = (char *)get_zeroed_page(GFP_KERNEL); |
2356 | if (!nosec) { | |
2357 | rc = -ENOMEM; | |
2358 | goto out; | |
2359 | } | |
2360 | ||
2361 | nosec_save = nosec; | |
2362 | fnosec = fsec = 1; | |
2363 | in_save = in_end = orig; | |
2364 | ||
2365 | do { | |
3528a953 CO |
2366 | if (*in_end == '"') |
2367 | open_quote = !open_quote; | |
2368 | if ((*in_end == ',' && open_quote == 0) || | |
2369 | *in_end == '\0') { | |
1da177e4 LT |
2370 | int len = in_end - in_curr; |
2371 | ||
2372 | if (selinux_option(in_curr, len)) | |
3528a953 | 2373 | take_selinux_option(&sec_curr, in_curr, &fsec, len); |
1da177e4 LT |
2374 | else |
2375 | take_option(&nosec, in_curr, &fnosec, len); | |
2376 | ||
2377 | in_curr = in_end + 1; | |
2378 | } | |
2379 | } while (*in_end++); | |
2380 | ||
6931dfc9 | 2381 | strcpy(in_save, nosec_save); |
da3caa20 | 2382 | free_page((unsigned long)nosec_save); |
1da177e4 LT |
2383 | out: |
2384 | return rc; | |
2385 | } | |
2386 | ||
026eb167 EP |
2387 | static int selinux_sb_remount(struct super_block *sb, void *data) |
2388 | { | |
2389 | int rc, i, *flags; | |
2390 | struct security_mnt_opts opts; | |
2391 | char *secdata, **mount_options; | |
2392 | struct superblock_security_struct *sbsec = sb->s_security; | |
2393 | ||
2394 | if (!(sbsec->flags & SE_SBINITIALIZED)) | |
2395 | return 0; | |
2396 | ||
2397 | if (!data) | |
2398 | return 0; | |
2399 | ||
2400 | if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) | |
2401 | return 0; | |
2402 | ||
2403 | security_init_mnt_opts(&opts); | |
2404 | secdata = alloc_secdata(); | |
2405 | if (!secdata) | |
2406 | return -ENOMEM; | |
2407 | rc = selinux_sb_copy_data(data, secdata); | |
2408 | if (rc) | |
2409 | goto out_free_secdata; | |
2410 | ||
2411 | rc = selinux_parse_opts_str(secdata, &opts); | |
2412 | if (rc) | |
2413 | goto out_free_secdata; | |
2414 | ||
2415 | mount_options = opts.mnt_opts; | |
2416 | flags = opts.mnt_opts_flags; | |
2417 | ||
2418 | for (i = 0; i < opts.num_mnt_opts; i++) { | |
2419 | u32 sid; | |
2420 | size_t len; | |
2421 | ||
2422 | if (flags[i] == SE_SBLABELSUPP) | |
2423 | continue; | |
2424 | len = strlen(mount_options[i]); | |
2425 | rc = security_context_to_sid(mount_options[i], len, &sid); | |
2426 | if (rc) { | |
2427 | printk(KERN_WARNING "SELinux: security_context_to_sid" | |
2428 | "(%s) failed for (dev %s, type %s) errno=%d\n", | |
2429 | mount_options[i], sb->s_id, sb->s_type->name, rc); | |
2430 | goto out_free_opts; | |
2431 | } | |
2432 | rc = -EINVAL; | |
2433 | switch (flags[i]) { | |
2434 | case FSCONTEXT_MNT: | |
2435 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) | |
2436 | goto out_bad_option; | |
2437 | break; | |
2438 | case CONTEXT_MNT: | |
2439 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) | |
2440 | goto out_bad_option; | |
2441 | break; | |
2442 | case ROOTCONTEXT_MNT: { | |
2443 | struct inode_security_struct *root_isec; | |
2444 | root_isec = sb->s_root->d_inode->i_security; | |
2445 | ||
2446 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) | |
2447 | goto out_bad_option; | |
2448 | break; | |
2449 | } | |
2450 | case DEFCONTEXT_MNT: | |
2451 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) | |
2452 | goto out_bad_option; | |
2453 | break; | |
2454 | default: | |
2455 | goto out_free_opts; | |
2456 | } | |
2457 | } | |
2458 | ||
2459 | rc = 0; | |
2460 | out_free_opts: | |
2461 | security_free_mnt_opts(&opts); | |
2462 | out_free_secdata: | |
2463 | free_secdata(secdata); | |
2464 | return rc; | |
2465 | out_bad_option: | |
2466 | printk(KERN_WARNING "SELinux: unable to change security options " | |
2467 | "during remount (dev %s, type=%s)\n", sb->s_id, | |
2468 | sb->s_type->name); | |
2469 | goto out_free_opts; | |
2470 | } | |
2471 | ||
12204e24 | 2472 | static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) |
1da177e4 | 2473 | { |
88e67f3b | 2474 | const struct cred *cred = current_cred(); |
2bf49690 | 2475 | struct common_audit_data ad; |
1da177e4 LT |
2476 | int rc; |
2477 | ||
2478 | rc = superblock_doinit(sb, data); | |
2479 | if (rc) | |
2480 | return rc; | |
2481 | ||
74192246 JM |
2482 | /* Allow all mounts performed by the kernel */ |
2483 | if (flags & MS_KERNMOUNT) | |
2484 | return 0; | |
2485 | ||
a269434d EP |
2486 | COMMON_AUDIT_DATA_INIT(&ad, DENTRY); |
2487 | ad.u.dentry = sb->s_root; | |
88e67f3b | 2488 | return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); |
1da177e4 LT |
2489 | } |
2490 | ||
726c3342 | 2491 | static int selinux_sb_statfs(struct dentry *dentry) |
1da177e4 | 2492 | { |
88e67f3b | 2493 | const struct cred *cred = current_cred(); |
2bf49690 | 2494 | struct common_audit_data ad; |
1da177e4 | 2495 | |
a269434d EP |
2496 | COMMON_AUDIT_DATA_INIT(&ad, DENTRY); |
2497 | ad.u.dentry = dentry->d_sb->s_root; | |
88e67f3b | 2498 | return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); |
1da177e4 LT |
2499 | } |
2500 | ||
828dfe1d | 2501 | static int selinux_mount(char *dev_name, |
b5266eb4 | 2502 | struct path *path, |
828dfe1d EP |
2503 | char *type, |
2504 | unsigned long flags, | |
2505 | void *data) | |
1da177e4 | 2506 | { |
88e67f3b | 2507 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2508 | |
2509 | if (flags & MS_REMOUNT) | |
88e67f3b | 2510 | return superblock_has_perm(cred, path->mnt->mnt_sb, |
828dfe1d | 2511 | FILESYSTEM__REMOUNT, NULL); |
1da177e4 | 2512 | else |
2875fa00 | 2513 | return path_has_perm(cred, path, FILE__MOUNTON); |
1da177e4 LT |
2514 | } |
2515 | ||
2516 | static int selinux_umount(struct vfsmount *mnt, int flags) | |
2517 | { | |
88e67f3b | 2518 | const struct cred *cred = current_cred(); |
1da177e4 | 2519 | |
88e67f3b | 2520 | return superblock_has_perm(cred, mnt->mnt_sb, |
828dfe1d | 2521 | FILESYSTEM__UNMOUNT, NULL); |
1da177e4 LT |
2522 | } |
2523 | ||
2524 | /* inode security operations */ | |
2525 | ||
2526 | static int selinux_inode_alloc_security(struct inode *inode) | |
2527 | { | |
2528 | return inode_alloc_security(inode); | |
2529 | } | |
2530 | ||
2531 | static void selinux_inode_free_security(struct inode *inode) | |
2532 | { | |
2533 | inode_free_security(inode); | |
2534 | } | |
2535 | ||
5e41ff9e | 2536 | static int selinux_inode_init_security(struct inode *inode, struct inode *dir, |
2a7dba39 EP |
2537 | const struct qstr *qstr, char **name, |
2538 | void **value, size_t *len) | |
5e41ff9e | 2539 | { |
5fb49870 | 2540 | const struct task_security_struct *tsec = current_security(); |
5e41ff9e SS |
2541 | struct inode_security_struct *dsec; |
2542 | struct superblock_security_struct *sbsec; | |
275bb41e | 2543 | u32 sid, newsid, clen; |
5e41ff9e | 2544 | int rc; |
570bc1c2 | 2545 | char *namep = NULL, *context; |
5e41ff9e | 2546 | |
5e41ff9e SS |
2547 | dsec = dir->i_security; |
2548 | sbsec = dir->i_sb->s_security; | |
5e41ff9e | 2549 | |
275bb41e DH |
2550 | sid = tsec->sid; |
2551 | newsid = tsec->create_sid; | |
2552 | ||
415103f9 EP |
2553 | if ((sbsec->flags & SE_SBINITIALIZED) && |
2554 | (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) | |
2555 | newsid = sbsec->mntpoint_sid; | |
2556 | else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { | |
275bb41e | 2557 | rc = security_transition_sid(sid, dsec->sid, |
5e41ff9e | 2558 | inode_mode_to_security_class(inode->i_mode), |
652bb9b0 | 2559 | qstr, &newsid); |
5e41ff9e SS |
2560 | if (rc) { |
2561 | printk(KERN_WARNING "%s: " | |
2562 | "security_transition_sid failed, rc=%d (dev=%s " | |
2563 | "ino=%ld)\n", | |
dd6f953a | 2564 | __func__, |
5e41ff9e SS |
2565 | -rc, inode->i_sb->s_id, inode->i_ino); |
2566 | return rc; | |
2567 | } | |
2568 | } | |
2569 | ||
296fddf7 | 2570 | /* Possibly defer initialization to selinux_complete_init. */ |
0d90a7ec | 2571 | if (sbsec->flags & SE_SBINITIALIZED) { |
296fddf7 EP |
2572 | struct inode_security_struct *isec = inode->i_security; |
2573 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
2574 | isec->sid = newsid; | |
2575 | isec->initialized = 1; | |
2576 | } | |
5e41ff9e | 2577 | |
cd89596f | 2578 | if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP)) |
25a74f3b SS |
2579 | return -EOPNOTSUPP; |
2580 | ||
570bc1c2 | 2581 | if (name) { |
a02fe132 | 2582 | namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS); |
570bc1c2 SS |
2583 | if (!namep) |
2584 | return -ENOMEM; | |
2585 | *name = namep; | |
2586 | } | |
5e41ff9e | 2587 | |
570bc1c2 | 2588 | if (value && len) { |
12b29f34 | 2589 | rc = security_sid_to_context_force(newsid, &context, &clen); |
570bc1c2 SS |
2590 | if (rc) { |
2591 | kfree(namep); | |
2592 | return rc; | |
2593 | } | |
2594 | *value = context; | |
2595 | *len = clen; | |
5e41ff9e | 2596 | } |
5e41ff9e | 2597 | |
5e41ff9e SS |
2598 | return 0; |
2599 | } | |
2600 | ||
4acdaf27 | 2601 | static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
2602 | { |
2603 | return may_create(dir, dentry, SECCLASS_FILE); | |
2604 | } | |
2605 | ||
1da177e4 LT |
2606 | static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) |
2607 | { | |
1da177e4 LT |
2608 | return may_link(dir, old_dentry, MAY_LINK); |
2609 | } | |
2610 | ||
1da177e4 LT |
2611 | static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) |
2612 | { | |
1da177e4 LT |
2613 | return may_link(dir, dentry, MAY_UNLINK); |
2614 | } | |
2615 | ||
2616 | static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) | |
2617 | { | |
2618 | return may_create(dir, dentry, SECCLASS_LNK_FILE); | |
2619 | } | |
2620 | ||
18bb1db3 | 2621 | static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) |
1da177e4 LT |
2622 | { |
2623 | return may_create(dir, dentry, SECCLASS_DIR); | |
2624 | } | |
2625 | ||
1da177e4 LT |
2626 | static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) |
2627 | { | |
2628 | return may_link(dir, dentry, MAY_RMDIR); | |
2629 | } | |
2630 | ||
1a67aafb | 2631 | static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 | 2632 | { |
1da177e4 LT |
2633 | return may_create(dir, dentry, inode_mode_to_security_class(mode)); |
2634 | } | |
2635 | ||
1da177e4 | 2636 | static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, |
828dfe1d | 2637 | struct inode *new_inode, struct dentry *new_dentry) |
1da177e4 LT |
2638 | { |
2639 | return may_rename(old_inode, old_dentry, new_inode, new_dentry); | |
2640 | } | |
2641 | ||
1da177e4 LT |
2642 | static int selinux_inode_readlink(struct dentry *dentry) |
2643 | { | |
88e67f3b DH |
2644 | const struct cred *cred = current_cred(); |
2645 | ||
2875fa00 | 2646 | return dentry_has_perm(cred, dentry, FILE__READ); |
1da177e4 LT |
2647 | } |
2648 | ||
2649 | static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata) | |
2650 | { | |
88e67f3b | 2651 | const struct cred *cred = current_cred(); |
1da177e4 | 2652 | |
2875fa00 | 2653 | return dentry_has_perm(cred, dentry, FILE__READ); |
1da177e4 LT |
2654 | } |
2655 | ||
e74f71eb | 2656 | static int selinux_inode_permission(struct inode *inode, int mask) |
1da177e4 | 2657 | { |
88e67f3b | 2658 | const struct cred *cred = current_cred(); |
b782e0a6 EP |
2659 | struct common_audit_data ad; |
2660 | u32 perms; | |
2661 | bool from_access; | |
cf1dd1da | 2662 | unsigned flags = mask & MAY_NOT_BLOCK; |
1da177e4 | 2663 | |
b782e0a6 | 2664 | from_access = mask & MAY_ACCESS; |
d09ca739 EP |
2665 | mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
2666 | ||
b782e0a6 EP |
2667 | /* No permission to check. Existence test. */ |
2668 | if (!mask) | |
1da177e4 | 2669 | return 0; |
1da177e4 | 2670 | |
f48b7399 EP |
2671 | COMMON_AUDIT_DATA_INIT(&ad, INODE); |
2672 | ad.u.inode = inode; | |
b782e0a6 EP |
2673 | |
2674 | if (from_access) | |
2675 | ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS; | |
2676 | ||
2677 | perms = file_mask_to_av(inode->i_mode, mask); | |
2678 | ||
9ade0cf4 | 2679 | return inode_has_perm(cred, inode, perms, &ad, flags); |
1da177e4 LT |
2680 | } |
2681 | ||
2682 | static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
2683 | { | |
88e67f3b | 2684 | const struct cred *cred = current_cred(); |
bc6a6008 | 2685 | unsigned int ia_valid = iattr->ia_valid; |
1da177e4 | 2686 | |
bc6a6008 AW |
2687 | /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ |
2688 | if (ia_valid & ATTR_FORCE) { | |
2689 | ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | | |
2690 | ATTR_FORCE); | |
2691 | if (!ia_valid) | |
2692 | return 0; | |
2693 | } | |
1da177e4 | 2694 | |
bc6a6008 AW |
2695 | if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | |
2696 | ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) | |
2875fa00 | 2697 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
1da177e4 | 2698 | |
2875fa00 | 2699 | return dentry_has_perm(cred, dentry, FILE__WRITE); |
1da177e4 LT |
2700 | } |
2701 | ||
2702 | static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) | |
2703 | { | |
88e67f3b | 2704 | const struct cred *cred = current_cred(); |
2875fa00 EP |
2705 | struct path path; |
2706 | ||
2707 | path.dentry = dentry; | |
2708 | path.mnt = mnt; | |
88e67f3b | 2709 | |
2875fa00 | 2710 | return path_has_perm(cred, &path, FILE__GETATTR); |
1da177e4 LT |
2711 | } |
2712 | ||
8f0cfa52 | 2713 | static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) |
b5376771 | 2714 | { |
88e67f3b DH |
2715 | const struct cred *cred = current_cred(); |
2716 | ||
b5376771 SH |
2717 | if (!strncmp(name, XATTR_SECURITY_PREFIX, |
2718 | sizeof XATTR_SECURITY_PREFIX - 1)) { | |
2719 | if (!strcmp(name, XATTR_NAME_CAPS)) { | |
2720 | if (!capable(CAP_SETFCAP)) | |
2721 | return -EPERM; | |
2722 | } else if (!capable(CAP_SYS_ADMIN)) { | |
2723 | /* A different attribute in the security namespace. | |
2724 | Restrict to administrator. */ | |
2725 | return -EPERM; | |
2726 | } | |
2727 | } | |
2728 | ||
2729 | /* Not an attribute we recognize, so just check the | |
2730 | ordinary setattr permission. */ | |
2875fa00 | 2731 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
b5376771 SH |
2732 | } |
2733 | ||
8f0cfa52 DH |
2734 | static int selinux_inode_setxattr(struct dentry *dentry, const char *name, |
2735 | const void *value, size_t size, int flags) | |
1da177e4 | 2736 | { |
1da177e4 LT |
2737 | struct inode *inode = dentry->d_inode; |
2738 | struct inode_security_struct *isec = inode->i_security; | |
2739 | struct superblock_security_struct *sbsec; | |
2bf49690 | 2740 | struct common_audit_data ad; |
275bb41e | 2741 | u32 newsid, sid = current_sid(); |
1da177e4 LT |
2742 | int rc = 0; |
2743 | ||
b5376771 SH |
2744 | if (strcmp(name, XATTR_NAME_SELINUX)) |
2745 | return selinux_inode_setotherxattr(dentry, name); | |
1da177e4 LT |
2746 | |
2747 | sbsec = inode->i_sb->s_security; | |
cd89596f | 2748 | if (!(sbsec->flags & SE_SBLABELSUPP)) |
1da177e4 LT |
2749 | return -EOPNOTSUPP; |
2750 | ||
2e149670 | 2751 | if (!inode_owner_or_capable(inode)) |
1da177e4 LT |
2752 | return -EPERM; |
2753 | ||
a269434d EP |
2754 | COMMON_AUDIT_DATA_INIT(&ad, DENTRY); |
2755 | ad.u.dentry = dentry; | |
1da177e4 | 2756 | |
275bb41e | 2757 | rc = avc_has_perm(sid, isec->sid, isec->sclass, |
1da177e4 LT |
2758 | FILE__RELABELFROM, &ad); |
2759 | if (rc) | |
2760 | return rc; | |
2761 | ||
2762 | rc = security_context_to_sid(value, size, &newsid); | |
12b29f34 SS |
2763 | if (rc == -EINVAL) { |
2764 | if (!capable(CAP_MAC_ADMIN)) | |
2765 | return rc; | |
2766 | rc = security_context_to_sid_force(value, size, &newsid); | |
2767 | } | |
1da177e4 LT |
2768 | if (rc) |
2769 | return rc; | |
2770 | ||
275bb41e | 2771 | rc = avc_has_perm(sid, newsid, isec->sclass, |
1da177e4 LT |
2772 | FILE__RELABELTO, &ad); |
2773 | if (rc) | |
2774 | return rc; | |
2775 | ||
275bb41e | 2776 | rc = security_validate_transition(isec->sid, newsid, sid, |
828dfe1d | 2777 | isec->sclass); |
1da177e4 LT |
2778 | if (rc) |
2779 | return rc; | |
2780 | ||
2781 | return avc_has_perm(newsid, | |
2782 | sbsec->sid, | |
2783 | SECCLASS_FILESYSTEM, | |
2784 | FILESYSTEM__ASSOCIATE, | |
2785 | &ad); | |
2786 | } | |
2787 | ||
8f0cfa52 | 2788 | static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, |
f5269710 | 2789 | const void *value, size_t size, |
8f0cfa52 | 2790 | int flags) |
1da177e4 LT |
2791 | { |
2792 | struct inode *inode = dentry->d_inode; | |
2793 | struct inode_security_struct *isec = inode->i_security; | |
2794 | u32 newsid; | |
2795 | int rc; | |
2796 | ||
2797 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
2798 | /* Not an attribute we recognize, so nothing to do. */ | |
2799 | return; | |
2800 | } | |
2801 | ||
12b29f34 | 2802 | rc = security_context_to_sid_force(value, size, &newsid); |
1da177e4 | 2803 | if (rc) { |
12b29f34 SS |
2804 | printk(KERN_ERR "SELinux: unable to map context to SID" |
2805 | "for (%s, %lu), rc=%d\n", | |
2806 | inode->i_sb->s_id, inode->i_ino, -rc); | |
1da177e4 LT |
2807 | return; |
2808 | } | |
2809 | ||
2810 | isec->sid = newsid; | |
2811 | return; | |
2812 | } | |
2813 | ||
8f0cfa52 | 2814 | static int selinux_inode_getxattr(struct dentry *dentry, const char *name) |
1da177e4 | 2815 | { |
88e67f3b DH |
2816 | const struct cred *cred = current_cred(); |
2817 | ||
2875fa00 | 2818 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
2819 | } |
2820 | ||
828dfe1d | 2821 | static int selinux_inode_listxattr(struct dentry *dentry) |
1da177e4 | 2822 | { |
88e67f3b DH |
2823 | const struct cred *cred = current_cred(); |
2824 | ||
2875fa00 | 2825 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
2826 | } |
2827 | ||
8f0cfa52 | 2828 | static int selinux_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 2829 | { |
b5376771 SH |
2830 | if (strcmp(name, XATTR_NAME_SELINUX)) |
2831 | return selinux_inode_setotherxattr(dentry, name); | |
1da177e4 LT |
2832 | |
2833 | /* No one is allowed to remove a SELinux security label. | |
2834 | You can change the label, but all data must be labeled. */ | |
2835 | return -EACCES; | |
2836 | } | |
2837 | ||
d381d8a9 | 2838 | /* |
abc69bb6 | 2839 | * Copy the inode security context value to the user. |
d381d8a9 JM |
2840 | * |
2841 | * Permission check is handled by selinux_inode_getxattr hook. | |
2842 | */ | |
42492594 | 2843 | static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) |
1da177e4 | 2844 | { |
42492594 DQ |
2845 | u32 size; |
2846 | int error; | |
2847 | char *context = NULL; | |
1da177e4 | 2848 | struct inode_security_struct *isec = inode->i_security; |
d381d8a9 | 2849 | |
8c8570fb DK |
2850 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) |
2851 | return -EOPNOTSUPP; | |
d381d8a9 | 2852 | |
abc69bb6 SS |
2853 | /* |
2854 | * If the caller has CAP_MAC_ADMIN, then get the raw context | |
2855 | * value even if it is not defined by current policy; otherwise, | |
2856 | * use the in-core value under current policy. | |
2857 | * Use the non-auditing forms of the permission checks since | |
2858 | * getxattr may be called by unprivileged processes commonly | |
2859 | * and lack of permission just means that we fall back to the | |
2860 | * in-core context value, not a denial. | |
2861 | */ | |
3486740a SH |
2862 | error = selinux_capable(current, current_cred(), |
2863 | &init_user_ns, CAP_MAC_ADMIN, | |
3699c53c | 2864 | SECURITY_CAP_NOAUDIT); |
abc69bb6 SS |
2865 | if (!error) |
2866 | error = security_sid_to_context_force(isec->sid, &context, | |
2867 | &size); | |
2868 | else | |
2869 | error = security_sid_to_context(isec->sid, &context, &size); | |
42492594 DQ |
2870 | if (error) |
2871 | return error; | |
2872 | error = size; | |
2873 | if (alloc) { | |
2874 | *buffer = context; | |
2875 | goto out_nofree; | |
2876 | } | |
2877 | kfree(context); | |
2878 | out_nofree: | |
2879 | return error; | |
1da177e4 LT |
2880 | } |
2881 | ||
2882 | static int selinux_inode_setsecurity(struct inode *inode, const char *name, | |
828dfe1d | 2883 | const void *value, size_t size, int flags) |
1da177e4 LT |
2884 | { |
2885 | struct inode_security_struct *isec = inode->i_security; | |
2886 | u32 newsid; | |
2887 | int rc; | |
2888 | ||
2889 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) | |
2890 | return -EOPNOTSUPP; | |
2891 | ||
2892 | if (!value || !size) | |
2893 | return -EACCES; | |
2894 | ||
828dfe1d | 2895 | rc = security_context_to_sid((void *)value, size, &newsid); |
1da177e4 LT |
2896 | if (rc) |
2897 | return rc; | |
2898 | ||
2899 | isec->sid = newsid; | |
ddd29ec6 | 2900 | isec->initialized = 1; |
1da177e4 LT |
2901 | return 0; |
2902 | } | |
2903 | ||
2904 | static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) | |
2905 | { | |
2906 | const int len = sizeof(XATTR_NAME_SELINUX); | |
2907 | if (buffer && len <= buffer_size) | |
2908 | memcpy(buffer, XATTR_NAME_SELINUX, len); | |
2909 | return len; | |
2910 | } | |
2911 | ||
713a04ae AD |
2912 | static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) |
2913 | { | |
2914 | struct inode_security_struct *isec = inode->i_security; | |
2915 | *secid = isec->sid; | |
2916 | } | |
2917 | ||
1da177e4 LT |
2918 | /* file security operations */ |
2919 | ||
788e7dd4 | 2920 | static int selinux_revalidate_file_permission(struct file *file, int mask) |
1da177e4 | 2921 | { |
88e67f3b | 2922 | const struct cred *cred = current_cred(); |
3d5ff529 | 2923 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 | 2924 | |
1da177e4 LT |
2925 | /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ |
2926 | if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) | |
2927 | mask |= MAY_APPEND; | |
2928 | ||
389fb800 PM |
2929 | return file_has_perm(cred, file, |
2930 | file_mask_to_av(inode->i_mode, mask)); | |
1da177e4 LT |
2931 | } |
2932 | ||
788e7dd4 YN |
2933 | static int selinux_file_permission(struct file *file, int mask) |
2934 | { | |
20dda18b SS |
2935 | struct inode *inode = file->f_path.dentry->d_inode; |
2936 | struct file_security_struct *fsec = file->f_security; | |
2937 | struct inode_security_struct *isec = inode->i_security; | |
2938 | u32 sid = current_sid(); | |
2939 | ||
389fb800 | 2940 | if (!mask) |
788e7dd4 YN |
2941 | /* No permission to check. Existence test. */ |
2942 | return 0; | |
788e7dd4 | 2943 | |
20dda18b SS |
2944 | if (sid == fsec->sid && fsec->isid == isec->sid && |
2945 | fsec->pseqno == avc_policy_seqno()) | |
2946 | /* No change since dentry_open check. */ | |
2947 | return 0; | |
2948 | ||
788e7dd4 YN |
2949 | return selinux_revalidate_file_permission(file, mask); |
2950 | } | |
2951 | ||
1da177e4 LT |
2952 | static int selinux_file_alloc_security(struct file *file) |
2953 | { | |
2954 | return file_alloc_security(file); | |
2955 | } | |
2956 | ||
2957 | static void selinux_file_free_security(struct file *file) | |
2958 | { | |
2959 | file_free_security(file); | |
2960 | } | |
2961 | ||
2962 | static int selinux_file_ioctl(struct file *file, unsigned int cmd, | |
2963 | unsigned long arg) | |
2964 | { | |
88e67f3b | 2965 | const struct cred *cred = current_cred(); |
0b24dcb7 | 2966 | int error = 0; |
1da177e4 | 2967 | |
0b24dcb7 EP |
2968 | switch (cmd) { |
2969 | case FIONREAD: | |
2970 | /* fall through */ | |
2971 | case FIBMAP: | |
2972 | /* fall through */ | |
2973 | case FIGETBSZ: | |
2974 | /* fall through */ | |
2975 | case EXT2_IOC_GETFLAGS: | |
2976 | /* fall through */ | |
2977 | case EXT2_IOC_GETVERSION: | |
2978 | error = file_has_perm(cred, file, FILE__GETATTR); | |
2979 | break; | |
1da177e4 | 2980 | |
0b24dcb7 EP |
2981 | case EXT2_IOC_SETFLAGS: |
2982 | /* fall through */ | |
2983 | case EXT2_IOC_SETVERSION: | |
2984 | error = file_has_perm(cred, file, FILE__SETATTR); | |
2985 | break; | |
2986 | ||
2987 | /* sys_ioctl() checks */ | |
2988 | case FIONBIO: | |
2989 | /* fall through */ | |
2990 | case FIOASYNC: | |
2991 | error = file_has_perm(cred, file, 0); | |
2992 | break; | |
1da177e4 | 2993 | |
0b24dcb7 EP |
2994 | case KDSKBENT: |
2995 | case KDSKBSENT: | |
2996 | error = task_has_capability(current, cred, CAP_SYS_TTY_CONFIG, | |
3486740a | 2997 | SECURITY_CAP_AUDIT); |
0b24dcb7 EP |
2998 | break; |
2999 | ||
3000 | /* default case assumes that the command will go | |
3001 | * to the file's ioctl() function. | |
3002 | */ | |
3003 | default: | |
3004 | error = file_has_perm(cred, file, FILE__IOCTL); | |
3005 | } | |
3006 | return error; | |
1da177e4 LT |
3007 | } |
3008 | ||
fcaaade1 SS |
3009 | static int default_noexec; |
3010 | ||
1da177e4 LT |
3011 | static int file_map_prot_check(struct file *file, unsigned long prot, int shared) |
3012 | { | |
88e67f3b | 3013 | const struct cred *cred = current_cred(); |
d84f4f99 | 3014 | int rc = 0; |
88e67f3b | 3015 | |
fcaaade1 SS |
3016 | if (default_noexec && |
3017 | (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) { | |
1da177e4 LT |
3018 | /* |
3019 | * We are making executable an anonymous mapping or a | |
3020 | * private file mapping that will also be writable. | |
3021 | * This has an additional check. | |
3022 | */ | |
d84f4f99 | 3023 | rc = cred_has_perm(cred, cred, PROCESS__EXECMEM); |
1da177e4 | 3024 | if (rc) |
d84f4f99 | 3025 | goto error; |
1da177e4 | 3026 | } |
1da177e4 LT |
3027 | |
3028 | if (file) { | |
3029 | /* read access is always possible with a mapping */ | |
3030 | u32 av = FILE__READ; | |
3031 | ||
3032 | /* write access only matters if the mapping is shared */ | |
3033 | if (shared && (prot & PROT_WRITE)) | |
3034 | av |= FILE__WRITE; | |
3035 | ||
3036 | if (prot & PROT_EXEC) | |
3037 | av |= FILE__EXECUTE; | |
3038 | ||
88e67f3b | 3039 | return file_has_perm(cred, file, av); |
1da177e4 | 3040 | } |
d84f4f99 DH |
3041 | |
3042 | error: | |
3043 | return rc; | |
1da177e4 LT |
3044 | } |
3045 | ||
3046 | static int selinux_file_mmap(struct file *file, unsigned long reqprot, | |
ed032189 EP |
3047 | unsigned long prot, unsigned long flags, |
3048 | unsigned long addr, unsigned long addr_only) | |
1da177e4 | 3049 | { |
ed032189 | 3050 | int rc = 0; |
275bb41e | 3051 | u32 sid = current_sid(); |
1da177e4 | 3052 | |
84336d1a EP |
3053 | /* |
3054 | * notice that we are intentionally putting the SELinux check before | |
3055 | * the secondary cap_file_mmap check. This is such a likely attempt | |
3056 | * at bad behaviour/exploit that we always want to get the AVC, even | |
3057 | * if DAC would have also denied the operation. | |
3058 | */ | |
a2551df7 | 3059 | if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { |
ed032189 EP |
3060 | rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, |
3061 | MEMPROTECT__MMAP_ZERO, NULL); | |
84336d1a EP |
3062 | if (rc) |
3063 | return rc; | |
3064 | } | |
3065 | ||
3066 | /* do DAC check on address space usage */ | |
3067 | rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); | |
ed032189 | 3068 | if (rc || addr_only) |
1da177e4 LT |
3069 | return rc; |
3070 | ||
3071 | if (selinux_checkreqprot) | |
3072 | prot = reqprot; | |
3073 | ||
3074 | return file_map_prot_check(file, prot, | |
3075 | (flags & MAP_TYPE) == MAP_SHARED); | |
3076 | } | |
3077 | ||
3078 | static int selinux_file_mprotect(struct vm_area_struct *vma, | |
3079 | unsigned long reqprot, | |
3080 | unsigned long prot) | |
3081 | { | |
88e67f3b | 3082 | const struct cred *cred = current_cred(); |
1da177e4 LT |
3083 | |
3084 | if (selinux_checkreqprot) | |
3085 | prot = reqprot; | |
3086 | ||
fcaaade1 SS |
3087 | if (default_noexec && |
3088 | (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { | |
d541bbee | 3089 | int rc = 0; |
db4c9641 SS |
3090 | if (vma->vm_start >= vma->vm_mm->start_brk && |
3091 | vma->vm_end <= vma->vm_mm->brk) { | |
d84f4f99 | 3092 | rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP); |
db4c9641 SS |
3093 | } else if (!vma->vm_file && |
3094 | vma->vm_start <= vma->vm_mm->start_stack && | |
3095 | vma->vm_end >= vma->vm_mm->start_stack) { | |
3b11a1de | 3096 | rc = current_has_perm(current, PROCESS__EXECSTACK); |
db4c9641 SS |
3097 | } else if (vma->vm_file && vma->anon_vma) { |
3098 | /* | |
3099 | * We are making executable a file mapping that has | |
3100 | * had some COW done. Since pages might have been | |
3101 | * written, check ability to execute the possibly | |
3102 | * modified content. This typically should only | |
3103 | * occur for text relocations. | |
3104 | */ | |
d84f4f99 | 3105 | rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); |
db4c9641 | 3106 | } |