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1da177e4 LT |
1 | /* |
2 | * NSA Security-Enhanced Linux (SELinux) security module | |
3 | * | |
4 | * This file contains the SELinux hook function implementations. | |
5 | * | |
6 | * Authors: Stephen Smalley, <sds@epoch.ncsc.mil> | |
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 LT |
30 | #include <linux/errno.h> |
31 | #include <linux/sched.h> | |
3c4ed7bd | 32 | #include <linux/lsm_hooks.h> |
1da177e4 LT |
33 | #include <linux/xattr.h> |
34 | #include <linux/capability.h> | |
35 | #include <linux/unistd.h> | |
36 | #include <linux/mm.h> | |
37 | #include <linux/mman.h> | |
38 | #include <linux/slab.h> | |
39 | #include <linux/pagemap.h> | |
0b24dcb7 | 40 | #include <linux/proc_fs.h> |
1da177e4 | 41 | #include <linux/swap.h> |
1da177e4 LT |
42 | #include <linux/spinlock.h> |
43 | #include <linux/syscalls.h> | |
2a7dba39 | 44 | #include <linux/dcache.h> |
1da177e4 | 45 | #include <linux/file.h> |
9f3acc31 | 46 | #include <linux/fdtable.h> |
1da177e4 LT |
47 | #include <linux/namei.h> |
48 | #include <linux/mount.h> | |
1da177e4 LT |
49 | #include <linux/netfilter_ipv4.h> |
50 | #include <linux/netfilter_ipv6.h> | |
51 | #include <linux/tty.h> | |
52 | #include <net/icmp.h> | |
227b60f5 | 53 | #include <net/ip.h> /* for local_port_range[] */ |
1da177e4 | 54 | #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ |
47180068 | 55 | #include <net/inet_connection_sock.h> |
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 */ | |
77954983 | 64 | #include <net/netlink.h> |
1da177e4 LT |
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> |
40401530 AV |
84 | #include <linux/msg.h> |
85 | #include <linux/shm.h> | |
1da177e4 LT |
86 | |
87 | #include "avc.h" | |
88 | #include "objsec.h" | |
89 | #include "netif.h" | |
224dfbd8 | 90 | #include "netnode.h" |
3e112172 | 91 | #include "netport.h" |
d28d1e08 | 92 | #include "xfrm.h" |
c60475bf | 93 | #include "netlabel.h" |
9d57a7f9 | 94 | #include "audit.h" |
7b98a585 | 95 | #include "avc_ss.h" |
1da177e4 | 96 | |
d621d35e | 97 | /* SECMARK reference count */ |
56a4ca99 | 98 | static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); |
d621d35e | 99 | |
1da177e4 | 100 | #ifdef CONFIG_SECURITY_SELINUX_DEVELOP |
828dfe1d | 101 | int selinux_enforcing; |
1da177e4 LT |
102 | |
103 | static int __init enforcing_setup(char *str) | |
104 | { | |
f5269710 | 105 | unsigned long enforcing; |
29707b20 | 106 | if (!kstrtoul(str, 0, &enforcing)) |
f5269710 | 107 | selinux_enforcing = enforcing ? 1 : 0; |
1da177e4 LT |
108 | return 1; |
109 | } | |
110 | __setup("enforcing=", enforcing_setup); | |
111 | #endif | |
112 | ||
113 | #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM | |
114 | int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; | |
115 | ||
116 | static int __init selinux_enabled_setup(char *str) | |
117 | { | |
f5269710 | 118 | unsigned long enabled; |
29707b20 | 119 | if (!kstrtoul(str, 0, &enabled)) |
f5269710 | 120 | selinux_enabled = enabled ? 1 : 0; |
1da177e4 LT |
121 | return 1; |
122 | } | |
123 | __setup("selinux=", selinux_enabled_setup); | |
30d55280 SS |
124 | #else |
125 | int selinux_enabled = 1; | |
1da177e4 LT |
126 | #endif |
127 | ||
e18b890b | 128 | static struct kmem_cache *sel_inode_cache; |
63205654 | 129 | static struct kmem_cache *file_security_cache; |
7cae7e26 | 130 | |
d621d35e PM |
131 | /** |
132 | * selinux_secmark_enabled - Check to see if SECMARK is currently enabled | |
133 | * | |
134 | * Description: | |
135 | * This function checks the SECMARK reference counter to see if any SECMARK | |
136 | * targets are currently configured, if the reference counter is greater than | |
137 | * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is | |
2be4d74f CP |
138 | * enabled, false (0) if SECMARK is disabled. If the always_check_network |
139 | * policy capability is enabled, SECMARK is always considered enabled. | |
d621d35e PM |
140 | * |
141 | */ | |
142 | static int selinux_secmark_enabled(void) | |
143 | { | |
2be4d74f CP |
144 | return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount)); |
145 | } | |
146 | ||
147 | /** | |
148 | * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled | |
149 | * | |
150 | * Description: | |
151 | * This function checks if NetLabel or labeled IPSEC is enabled. Returns true | |
152 | * (1) if any are enabled or false (0) if neither are enabled. If the | |
153 | * always_check_network policy capability is enabled, peer labeling | |
154 | * is always considered enabled. | |
155 | * | |
156 | */ | |
157 | static int selinux_peerlbl_enabled(void) | |
158 | { | |
159 | return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled()); | |
d621d35e PM |
160 | } |
161 | ||
615e51fd PM |
162 | static int selinux_netcache_avc_callback(u32 event) |
163 | { | |
164 | if (event == AVC_CALLBACK_RESET) { | |
165 | sel_netif_flush(); | |
166 | sel_netnode_flush(); | |
167 | sel_netport_flush(); | |
168 | synchronize_net(); | |
169 | } | |
170 | return 0; | |
171 | } | |
172 | ||
d84f4f99 DH |
173 | /* |
174 | * initialise the security for the init task | |
175 | */ | |
176 | static void cred_init_security(void) | |
1da177e4 | 177 | { |
3b11a1de | 178 | struct cred *cred = (struct cred *) current->real_cred; |
1da177e4 LT |
179 | struct task_security_struct *tsec; |
180 | ||
89d155ef | 181 | tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); |
1da177e4 | 182 | if (!tsec) |
d84f4f99 | 183 | panic("SELinux: Failed to initialize initial task.\n"); |
1da177e4 | 184 | |
d84f4f99 | 185 | tsec->osid = tsec->sid = SECINITSID_KERNEL; |
f1752eec | 186 | cred->security = tsec; |
1da177e4 LT |
187 | } |
188 | ||
88e67f3b DH |
189 | /* |
190 | * get the security ID of a set of credentials | |
191 | */ | |
192 | static inline u32 cred_sid(const struct cred *cred) | |
193 | { | |
194 | const struct task_security_struct *tsec; | |
195 | ||
196 | tsec = cred->security; | |
197 | return tsec->sid; | |
198 | } | |
199 | ||
275bb41e | 200 | /* |
3b11a1de | 201 | * get the objective security ID of a task |
275bb41e DH |
202 | */ |
203 | static inline u32 task_sid(const struct task_struct *task) | |
204 | { | |
275bb41e DH |
205 | u32 sid; |
206 | ||
207 | rcu_read_lock(); | |
88e67f3b | 208 | sid = cred_sid(__task_cred(task)); |
275bb41e DH |
209 | rcu_read_unlock(); |
210 | return sid; | |
211 | } | |
212 | ||
88e67f3b DH |
213 | /* Allocate and free functions for each kind of security blob. */ |
214 | ||
1da177e4 LT |
215 | static int inode_alloc_security(struct inode *inode) |
216 | { | |
1da177e4 | 217 | struct inode_security_struct *isec; |
275bb41e | 218 | u32 sid = current_sid(); |
1da177e4 | 219 | |
a02fe132 | 220 | isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); |
1da177e4 LT |
221 | if (!isec) |
222 | return -ENOMEM; | |
223 | ||
9287aed2 | 224 | spin_lock_init(&isec->lock); |
1da177e4 | 225 | INIT_LIST_HEAD(&isec->list); |
1da177e4 LT |
226 | isec->inode = inode; |
227 | isec->sid = SECINITSID_UNLABELED; | |
228 | isec->sclass = SECCLASS_FILE; | |
275bb41e | 229 | isec->task_sid = sid; |
42059112 | 230 | isec->initialized = LABEL_INVALID; |
1da177e4 LT |
231 | inode->i_security = isec; |
232 | ||
233 | return 0; | |
234 | } | |
235 | ||
5d226df4 AG |
236 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); |
237 | ||
238 | /* | |
239 | * Try reloading inode security labels that have been marked as invalid. The | |
240 | * @may_sleep parameter indicates when sleeping and thus reloading labels is | |
42059112 | 241 | * allowed; when set to false, returns -ECHILD when the label is |
5d226df4 AG |
242 | * invalid. The @opt_dentry parameter should be set to a dentry of the inode; |
243 | * when no dentry is available, set it to NULL instead. | |
244 | */ | |
245 | static int __inode_security_revalidate(struct inode *inode, | |
246 | struct dentry *opt_dentry, | |
247 | bool may_sleep) | |
248 | { | |
249 | struct inode_security_struct *isec = inode->i_security; | |
250 | ||
251 | might_sleep_if(may_sleep); | |
252 | ||
1ac42476 | 253 | if (ss_initialized && isec->initialized != LABEL_INITIALIZED) { |
5d226df4 AG |
254 | if (!may_sleep) |
255 | return -ECHILD; | |
256 | ||
257 | /* | |
258 | * Try reloading the inode security label. This will fail if | |
259 | * @opt_dentry is NULL and no dentry for this inode can be | |
260 | * found; in that case, continue using the old label. | |
261 | */ | |
262 | inode_doinit_with_dentry(inode, opt_dentry); | |
263 | } | |
264 | return 0; | |
265 | } | |
266 | ||
5d226df4 AG |
267 | static struct inode_security_struct *inode_security_novalidate(struct inode *inode) |
268 | { | |
269 | return inode->i_security; | |
270 | } | |
271 | ||
272 | static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu) | |
273 | { | |
274 | int error; | |
275 | ||
276 | error = __inode_security_revalidate(inode, NULL, !rcu); | |
277 | if (error) | |
278 | return ERR_PTR(error); | |
279 | return inode->i_security; | |
280 | } | |
281 | ||
83da53c5 AG |
282 | /* |
283 | * Get the security label of an inode. | |
284 | */ | |
285 | static struct inode_security_struct *inode_security(struct inode *inode) | |
286 | { | |
5d226df4 | 287 | __inode_security_revalidate(inode, NULL, true); |
83da53c5 AG |
288 | return inode->i_security; |
289 | } | |
290 | ||
2c97165b PM |
291 | static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry) |
292 | { | |
293 | struct inode *inode = d_backing_inode(dentry); | |
294 | ||
295 | return inode->i_security; | |
296 | } | |
297 | ||
83da53c5 AG |
298 | /* |
299 | * Get the security label of a dentry's backing inode. | |
300 | */ | |
301 | static struct inode_security_struct *backing_inode_security(struct dentry *dentry) | |
302 | { | |
303 | struct inode *inode = d_backing_inode(dentry); | |
304 | ||
5d226df4 | 305 | __inode_security_revalidate(inode, dentry, true); |
83da53c5 AG |
306 | return inode->i_security; |
307 | } | |
308 | ||
3dc91d43 SR |
309 | static void inode_free_rcu(struct rcu_head *head) |
310 | { | |
311 | struct inode_security_struct *isec; | |
312 | ||
313 | isec = container_of(head, struct inode_security_struct, rcu); | |
314 | kmem_cache_free(sel_inode_cache, isec); | |
315 | } | |
316 | ||
1da177e4 LT |
317 | static void inode_free_security(struct inode *inode) |
318 | { | |
319 | struct inode_security_struct *isec = inode->i_security; | |
320 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; | |
321 | ||
9629d04a WL |
322 | /* |
323 | * As not all inode security structures are in a list, we check for | |
324 | * empty list outside of the lock to make sure that we won't waste | |
325 | * time taking a lock doing nothing. | |
326 | * | |
327 | * The list_del_init() function can be safely called more than once. | |
328 | * It should not be possible for this function to be called with | |
329 | * concurrent list_add(), but for better safety against future changes | |
330 | * in the code, we use list_empty_careful() here. | |
331 | */ | |
332 | if (!list_empty_careful(&isec->list)) { | |
333 | spin_lock(&sbsec->isec_lock); | |
1da177e4 | 334 | list_del_init(&isec->list); |
9629d04a WL |
335 | spin_unlock(&sbsec->isec_lock); |
336 | } | |
1da177e4 | 337 | |
3dc91d43 SR |
338 | /* |
339 | * The inode may still be referenced in a path walk and | |
340 | * a call to selinux_inode_permission() can be made | |
341 | * after inode_free_security() is called. Ideally, the VFS | |
342 | * wouldn't do this, but fixing that is a much harder | |
343 | * job. For now, simply free the i_security via RCU, and | |
344 | * leave the current inode->i_security pointer intact. | |
345 | * The inode will be freed after the RCU grace period too. | |
346 | */ | |
347 | call_rcu(&isec->rcu, inode_free_rcu); | |
1da177e4 LT |
348 | } |
349 | ||
350 | static int file_alloc_security(struct file *file) | |
351 | { | |
1da177e4 | 352 | struct file_security_struct *fsec; |
275bb41e | 353 | u32 sid = current_sid(); |
1da177e4 | 354 | |
63205654 | 355 | fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL); |
1da177e4 LT |
356 | if (!fsec) |
357 | return -ENOMEM; | |
358 | ||
275bb41e DH |
359 | fsec->sid = sid; |
360 | fsec->fown_sid = sid; | |
1da177e4 LT |
361 | file->f_security = fsec; |
362 | ||
363 | return 0; | |
364 | } | |
365 | ||
366 | static void file_free_security(struct file *file) | |
367 | { | |
368 | struct file_security_struct *fsec = file->f_security; | |
1da177e4 | 369 | file->f_security = NULL; |
63205654 | 370 | kmem_cache_free(file_security_cache, fsec); |
1da177e4 LT |
371 | } |
372 | ||
373 | static int superblock_alloc_security(struct super_block *sb) | |
374 | { | |
375 | struct superblock_security_struct *sbsec; | |
376 | ||
89d155ef | 377 | sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); |
1da177e4 LT |
378 | if (!sbsec) |
379 | return -ENOMEM; | |
380 | ||
bc7e982b | 381 | mutex_init(&sbsec->lock); |
1da177e4 LT |
382 | INIT_LIST_HEAD(&sbsec->isec_head); |
383 | spin_lock_init(&sbsec->isec_lock); | |
1da177e4 LT |
384 | sbsec->sb = sb; |
385 | sbsec->sid = SECINITSID_UNLABELED; | |
386 | sbsec->def_sid = SECINITSID_FILE; | |
c312feb2 | 387 | sbsec->mntpoint_sid = SECINITSID_UNLABELED; |
1da177e4 LT |
388 | sb->s_security = sbsec; |
389 | ||
390 | return 0; | |
391 | } | |
392 | ||
393 | static void superblock_free_security(struct super_block *sb) | |
394 | { | |
395 | struct superblock_security_struct *sbsec = sb->s_security; | |
1da177e4 LT |
396 | sb->s_security = NULL; |
397 | kfree(sbsec); | |
398 | } | |
399 | ||
1da177e4 LT |
400 | /* The file system's label must be initialized prior to use. */ |
401 | ||
eb9ae686 | 402 | static const char *labeling_behaviors[7] = { |
1da177e4 LT |
403 | "uses xattr", |
404 | "uses transition SIDs", | |
405 | "uses task SIDs", | |
406 | "uses genfs_contexts", | |
407 | "not configured for labeling", | |
408 | "uses mountpoint labeling", | |
eb9ae686 | 409 | "uses native labeling", |
1da177e4 LT |
410 | }; |
411 | ||
1da177e4 LT |
412 | static inline int inode_doinit(struct inode *inode) |
413 | { | |
414 | return inode_doinit_with_dentry(inode, NULL); | |
415 | } | |
416 | ||
417 | enum { | |
31e87930 | 418 | Opt_error = -1, |
1da177e4 LT |
419 | Opt_context = 1, |
420 | Opt_fscontext = 2, | |
c9180a57 EP |
421 | Opt_defcontext = 3, |
422 | Opt_rootcontext = 4, | |
11689d47 | 423 | Opt_labelsupport = 5, |
d355987f | 424 | Opt_nextmntopt = 6, |
1da177e4 LT |
425 | }; |
426 | ||
d355987f EP |
427 | #define NUM_SEL_MNT_OPTS (Opt_nextmntopt - 1) |
428 | ||
a447c093 | 429 | static const match_table_t tokens = { |
832cbd9a EP |
430 | {Opt_context, CONTEXT_STR "%s"}, |
431 | {Opt_fscontext, FSCONTEXT_STR "%s"}, | |
432 | {Opt_defcontext, DEFCONTEXT_STR "%s"}, | |
433 | {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, | |
11689d47 | 434 | {Opt_labelsupport, LABELSUPP_STR}, |
31e87930 | 435 | {Opt_error, NULL}, |
1da177e4 LT |
436 | }; |
437 | ||
438 | #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" | |
439 | ||
c312feb2 EP |
440 | static int may_context_mount_sb_relabel(u32 sid, |
441 | struct superblock_security_struct *sbsec, | |
275bb41e | 442 | const struct cred *cred) |
c312feb2 | 443 | { |
275bb41e | 444 | const struct task_security_struct *tsec = cred->security; |
c312feb2 EP |
445 | int rc; |
446 | ||
447 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
448 | FILESYSTEM__RELABELFROM, NULL); | |
449 | if (rc) | |
450 | return rc; | |
451 | ||
452 | rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, | |
453 | FILESYSTEM__RELABELTO, NULL); | |
454 | return rc; | |
455 | } | |
456 | ||
0808925e EP |
457 | static int may_context_mount_inode_relabel(u32 sid, |
458 | struct superblock_security_struct *sbsec, | |
275bb41e | 459 | const struct cred *cred) |
0808925e | 460 | { |
275bb41e | 461 | const struct task_security_struct *tsec = cred->security; |
0808925e EP |
462 | int rc; |
463 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
464 | FILESYSTEM__RELABELFROM, NULL); | |
465 | if (rc) | |
466 | return rc; | |
467 | ||
468 | rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
469 | FILESYSTEM__ASSOCIATE, NULL); | |
470 | return rc; | |
471 | } | |
472 | ||
b43e725d EP |
473 | static int selinux_is_sblabel_mnt(struct super_block *sb) |
474 | { | |
475 | struct superblock_security_struct *sbsec = sb->s_security; | |
476 | ||
d5f3a5f6 MS |
477 | return sbsec->behavior == SECURITY_FS_USE_XATTR || |
478 | sbsec->behavior == SECURITY_FS_USE_TRANS || | |
479 | sbsec->behavior == SECURITY_FS_USE_TASK || | |
9fc2b4b4 | 480 | sbsec->behavior == SECURITY_FS_USE_NATIVE || |
d5f3a5f6 MS |
481 | /* Special handling. Genfs but also in-core setxattr handler */ |
482 | !strcmp(sb->s_type->name, "sysfs") || | |
1ea0ce40 AM |
483 | !strcmp(sb->s_type->name, "cgroup") || |
484 | !strcmp(sb->s_type->name, "cgroup2") || | |
d5f3a5f6 MS |
485 | !strcmp(sb->s_type->name, "pstore") || |
486 | !strcmp(sb->s_type->name, "debugfs") || | |
a2c7c6fb | 487 | !strcmp(sb->s_type->name, "tracefs") || |
d5f3a5f6 | 488 | !strcmp(sb->s_type->name, "rootfs"); |
b43e725d EP |
489 | } |
490 | ||
c9180a57 | 491 | static int sb_finish_set_opts(struct super_block *sb) |
1da177e4 | 492 | { |
1da177e4 | 493 | struct superblock_security_struct *sbsec = sb->s_security; |
c9180a57 | 494 | struct dentry *root = sb->s_root; |
c6f493d6 | 495 | struct inode *root_inode = d_backing_inode(root); |
c9180a57 | 496 | int rc = 0; |
1da177e4 | 497 | |
c9180a57 EP |
498 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { |
499 | /* Make sure that the xattr handler exists and that no | |
500 | error other than -ENODATA is returned by getxattr on | |
501 | the root directory. -ENODATA is ok, as this may be | |
502 | the first boot of the SELinux kernel before we have | |
503 | assigned xattr values to the filesystem. */ | |
5d6c3191 | 504 | if (!(root_inode->i_opflags & IOP_XATTR)) { |
29b1deb2 LT |
505 | printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " |
506 | "xattr support\n", sb->s_id, sb->s_type->name); | |
c9180a57 EP |
507 | rc = -EOPNOTSUPP; |
508 | goto out; | |
509 | } | |
5d6c3191 AG |
510 | |
511 | rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0); | |
c9180a57 EP |
512 | if (rc < 0 && rc != -ENODATA) { |
513 | if (rc == -EOPNOTSUPP) | |
514 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
29b1deb2 LT |
515 | "%s) has no security xattr handler\n", |
516 | sb->s_id, sb->s_type->name); | |
c9180a57 EP |
517 | else |
518 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
29b1deb2 LT |
519 | "%s) getxattr errno %d\n", sb->s_id, |
520 | sb->s_type->name, -rc); | |
c9180a57 EP |
521 | goto out; |
522 | } | |
523 | } | |
1da177e4 | 524 | |
c9180a57 | 525 | if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) |
29b1deb2 LT |
526 | printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", |
527 | sb->s_id, sb->s_type->name); | |
1da177e4 | 528 | |
eadcabc6 | 529 | sbsec->flags |= SE_SBINITIALIZED; |
b43e725d | 530 | if (selinux_is_sblabel_mnt(sb)) |
12f348b9 | 531 | sbsec->flags |= SBLABEL_MNT; |
ddd29ec6 | 532 | |
c9180a57 EP |
533 | /* Initialize the root inode. */ |
534 | rc = inode_doinit_with_dentry(root_inode, root); | |
1da177e4 | 535 | |
c9180a57 EP |
536 | /* Initialize any other inodes associated with the superblock, e.g. |
537 | inodes created prior to initial policy load or inodes created | |
538 | during get_sb by a pseudo filesystem that directly | |
539 | populates itself. */ | |
540 | spin_lock(&sbsec->isec_lock); | |
541 | next_inode: | |
542 | if (!list_empty(&sbsec->isec_head)) { | |
543 | struct inode_security_struct *isec = | |
544 | list_entry(sbsec->isec_head.next, | |
545 | struct inode_security_struct, list); | |
546 | struct inode *inode = isec->inode; | |
923190d3 | 547 | list_del_init(&isec->list); |
c9180a57 EP |
548 | spin_unlock(&sbsec->isec_lock); |
549 | inode = igrab(inode); | |
550 | if (inode) { | |
551 | if (!IS_PRIVATE(inode)) | |
552 | inode_doinit(inode); | |
553 | iput(inode); | |
554 | } | |
555 | spin_lock(&sbsec->isec_lock); | |
c9180a57 EP |
556 | goto next_inode; |
557 | } | |
558 | spin_unlock(&sbsec->isec_lock); | |
559 | out: | |
560 | return rc; | |
561 | } | |
1da177e4 | 562 | |
c9180a57 EP |
563 | /* |
564 | * This function should allow an FS to ask what it's mount security | |
565 | * options were so it can use those later for submounts, displaying | |
566 | * mount options, or whatever. | |
567 | */ | |
568 | static int selinux_get_mnt_opts(const struct super_block *sb, | |
e0007529 | 569 | struct security_mnt_opts *opts) |
c9180a57 EP |
570 | { |
571 | int rc = 0, i; | |
572 | struct superblock_security_struct *sbsec = sb->s_security; | |
573 | char *context = NULL; | |
574 | u32 len; | |
575 | char tmp; | |
1da177e4 | 576 | |
e0007529 | 577 | security_init_mnt_opts(opts); |
1da177e4 | 578 | |
0d90a7ec | 579 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
c9180a57 | 580 | return -EINVAL; |
1da177e4 | 581 | |
c9180a57 EP |
582 | if (!ss_initialized) |
583 | return -EINVAL; | |
1da177e4 | 584 | |
af8e50cc EP |
585 | /* make sure we always check enough bits to cover the mask */ |
586 | BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS)); | |
587 | ||
0d90a7ec | 588 | tmp = sbsec->flags & SE_MNTMASK; |
c9180a57 | 589 | /* count the number of mount options for this sb */ |
af8e50cc | 590 | for (i = 0; i < NUM_SEL_MNT_OPTS; i++) { |
c9180a57 | 591 | if (tmp & 0x01) |
e0007529 | 592 | opts->num_mnt_opts++; |
c9180a57 EP |
593 | tmp >>= 1; |
594 | } | |
11689d47 | 595 | /* Check if the Label support flag is set */ |
0b4bdb35 | 596 | if (sbsec->flags & SBLABEL_MNT) |
11689d47 | 597 | opts->num_mnt_opts++; |
1da177e4 | 598 | |
e0007529 EP |
599 | opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); |
600 | if (!opts->mnt_opts) { | |
c9180a57 EP |
601 | rc = -ENOMEM; |
602 | goto out_free; | |
603 | } | |
1da177e4 | 604 | |
e0007529 EP |
605 | opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); |
606 | if (!opts->mnt_opts_flags) { | |
c9180a57 EP |
607 | rc = -ENOMEM; |
608 | goto out_free; | |
609 | } | |
1da177e4 | 610 | |
c9180a57 EP |
611 | i = 0; |
612 | if (sbsec->flags & FSCONTEXT_MNT) { | |
613 | rc = security_sid_to_context(sbsec->sid, &context, &len); | |
614 | if (rc) | |
615 | goto out_free; | |
e0007529 EP |
616 | opts->mnt_opts[i] = context; |
617 | opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; | |
c9180a57 EP |
618 | } |
619 | if (sbsec->flags & CONTEXT_MNT) { | |
620 | rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); | |
621 | if (rc) | |
622 | goto out_free; | |
e0007529 EP |
623 | opts->mnt_opts[i] = context; |
624 | opts->mnt_opts_flags[i++] = CONTEXT_MNT; | |
c9180a57 EP |
625 | } |
626 | if (sbsec->flags & DEFCONTEXT_MNT) { | |
627 | rc = security_sid_to_context(sbsec->def_sid, &context, &len); | |
628 | if (rc) | |
629 | goto out_free; | |
e0007529 EP |
630 | opts->mnt_opts[i] = context; |
631 | opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; | |
c9180a57 EP |
632 | } |
633 | if (sbsec->flags & ROOTCONTEXT_MNT) { | |
83da53c5 AG |
634 | struct dentry *root = sbsec->sb->s_root; |
635 | struct inode_security_struct *isec = backing_inode_security(root); | |
0808925e | 636 | |
c9180a57 EP |
637 | rc = security_sid_to_context(isec->sid, &context, &len); |
638 | if (rc) | |
639 | goto out_free; | |
e0007529 EP |
640 | opts->mnt_opts[i] = context; |
641 | opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; | |
c9180a57 | 642 | } |
12f348b9 | 643 | if (sbsec->flags & SBLABEL_MNT) { |
11689d47 | 644 | opts->mnt_opts[i] = NULL; |
12f348b9 | 645 | opts->mnt_opts_flags[i++] = SBLABEL_MNT; |
11689d47 | 646 | } |
1da177e4 | 647 | |
e0007529 | 648 | BUG_ON(i != opts->num_mnt_opts); |
1da177e4 | 649 | |
c9180a57 EP |
650 | return 0; |
651 | ||
652 | out_free: | |
e0007529 | 653 | security_free_mnt_opts(opts); |
c9180a57 EP |
654 | return rc; |
655 | } | |
1da177e4 | 656 | |
c9180a57 EP |
657 | static int bad_option(struct superblock_security_struct *sbsec, char flag, |
658 | u32 old_sid, u32 new_sid) | |
659 | { | |
0d90a7ec DQ |
660 | char mnt_flags = sbsec->flags & SE_MNTMASK; |
661 | ||
c9180a57 | 662 | /* check if the old mount command had the same options */ |
0d90a7ec | 663 | if (sbsec->flags & SE_SBINITIALIZED) |
c9180a57 EP |
664 | if (!(sbsec->flags & flag) || |
665 | (old_sid != new_sid)) | |
666 | return 1; | |
667 | ||
668 | /* check if we were passed the same options twice, | |
669 | * aka someone passed context=a,context=b | |
670 | */ | |
0d90a7ec DQ |
671 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
672 | if (mnt_flags & flag) | |
c9180a57 EP |
673 | return 1; |
674 | return 0; | |
675 | } | |
e0007529 | 676 | |
c9180a57 EP |
677 | /* |
678 | * Allow filesystems with binary mount data to explicitly set mount point | |
679 | * labeling information. | |
680 | */ | |
e0007529 | 681 | static int selinux_set_mnt_opts(struct super_block *sb, |
649f6e77 DQ |
682 | struct security_mnt_opts *opts, |
683 | unsigned long kern_flags, | |
684 | unsigned long *set_kern_flags) | |
c9180a57 | 685 | { |
275bb41e | 686 | const struct cred *cred = current_cred(); |
c9180a57 | 687 | int rc = 0, i; |
c9180a57 | 688 | struct superblock_security_struct *sbsec = sb->s_security; |
29b1deb2 | 689 | const char *name = sb->s_type->name; |
83da53c5 | 690 | struct dentry *root = sbsec->sb->s_root; |
2c97165b | 691 | struct inode_security_struct *root_isec; |
c9180a57 EP |
692 | u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; |
693 | u32 defcontext_sid = 0; | |
e0007529 EP |
694 | char **mount_options = opts->mnt_opts; |
695 | int *flags = opts->mnt_opts_flags; | |
696 | int num_opts = opts->num_mnt_opts; | |
c9180a57 EP |
697 | |
698 | mutex_lock(&sbsec->lock); | |
699 | ||
700 | if (!ss_initialized) { | |
701 | if (!num_opts) { | |
702 | /* Defer initialization until selinux_complete_init, | |
703 | after the initial policy is loaded and the security | |
704 | server is ready to handle calls. */ | |
c9180a57 EP |
705 | goto out; |
706 | } | |
707 | rc = -EINVAL; | |
744ba35e EP |
708 | printk(KERN_WARNING "SELinux: Unable to set superblock options " |
709 | "before the security server is initialized\n"); | |
1da177e4 | 710 | goto out; |
c9180a57 | 711 | } |
649f6e77 DQ |
712 | if (kern_flags && !set_kern_flags) { |
713 | /* Specifying internal flags without providing a place to | |
714 | * place the results is not allowed */ | |
715 | rc = -EINVAL; | |
716 | goto out; | |
717 | } | |
1da177e4 | 718 | |
e0007529 EP |
719 | /* |
720 | * Binary mount data FS will come through this function twice. Once | |
721 | * from an explicit call and once from the generic calls from the vfs. | |
722 | * Since the generic VFS calls will not contain any security mount data | |
723 | * we need to skip the double mount verification. | |
724 | * | |
725 | * This does open a hole in which we will not notice if the first | |
726 | * mount using this sb set explict options and a second mount using | |
727 | * this sb does not set any security options. (The first options | |
728 | * will be used for both mounts) | |
729 | */ | |
0d90a7ec | 730 | if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) |
e0007529 | 731 | && (num_opts == 0)) |
f5269710 | 732 | goto out; |
e0007529 | 733 | |
2c97165b PM |
734 | root_isec = backing_inode_security_novalidate(root); |
735 | ||
c9180a57 EP |
736 | /* |
737 | * parse the mount options, check if they are valid sids. | |
738 | * also check if someone is trying to mount the same sb more | |
739 | * than once with different security options. | |
740 | */ | |
741 | for (i = 0; i < num_opts; i++) { | |
742 | u32 sid; | |
11689d47 | 743 | |
12f348b9 | 744 | if (flags[i] == SBLABEL_MNT) |
11689d47 | 745 | continue; |
44be2f65 | 746 | rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL); |
1da177e4 | 747 | if (rc) { |
44be2f65 | 748 | printk(KERN_WARNING "SELinux: security_context_str_to_sid" |
29b1deb2 LT |
749 | "(%s) failed for (dev %s, type %s) errno=%d\n", |
750 | mount_options[i], sb->s_id, name, rc); | |
c9180a57 EP |
751 | goto out; |
752 | } | |
753 | switch (flags[i]) { | |
754 | case FSCONTEXT_MNT: | |
755 | fscontext_sid = sid; | |
756 | ||
757 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, | |
758 | fscontext_sid)) | |
759 | goto out_double_mount; | |
760 | ||
761 | sbsec->flags |= FSCONTEXT_MNT; | |
762 | break; | |
763 | case CONTEXT_MNT: | |
764 | context_sid = sid; | |
765 | ||
766 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, | |
767 | context_sid)) | |
768 | goto out_double_mount; | |
769 | ||
770 | sbsec->flags |= CONTEXT_MNT; | |
771 | break; | |
772 | case ROOTCONTEXT_MNT: | |
773 | rootcontext_sid = sid; | |
774 | ||
775 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, | |
776 | rootcontext_sid)) | |
777 | goto out_double_mount; | |
778 | ||
779 | sbsec->flags |= ROOTCONTEXT_MNT; | |
780 | ||
781 | break; | |
782 | case DEFCONTEXT_MNT: | |
783 | defcontext_sid = sid; | |
784 | ||
785 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, | |
786 | defcontext_sid)) | |
787 | goto out_double_mount; | |
788 | ||
789 | sbsec->flags |= DEFCONTEXT_MNT; | |
790 | ||
791 | break; | |
792 | default: | |
793 | rc = -EINVAL; | |
794 | goto out; | |
1da177e4 | 795 | } |
c9180a57 EP |
796 | } |
797 | ||
0d90a7ec | 798 | if (sbsec->flags & SE_SBINITIALIZED) { |
c9180a57 | 799 | /* previously mounted with options, but not on this attempt? */ |
0d90a7ec | 800 | if ((sbsec->flags & SE_MNTMASK) && !num_opts) |
c9180a57 EP |
801 | goto out_double_mount; |
802 | rc = 0; | |
803 | goto out; | |
804 | } | |
805 | ||
089be43e | 806 | if (strcmp(sb->s_type->name, "proc") == 0) |
134509d5 SS |
807 | sbsec->flags |= SE_SBPROC | SE_SBGENFS; |
808 | ||
8e014720 SS |
809 | if (!strcmp(sb->s_type->name, "debugfs") || |
810 | !strcmp(sb->s_type->name, "sysfs") || | |
811 | !strcmp(sb->s_type->name, "pstore")) | |
134509d5 | 812 | sbsec->flags |= SE_SBGENFS; |
c9180a57 | 813 | |
eb9ae686 DQ |
814 | if (!sbsec->behavior) { |
815 | /* | |
816 | * Determine the labeling behavior to use for this | |
817 | * filesystem type. | |
818 | */ | |
98f700f3 | 819 | rc = security_fs_use(sb); |
eb9ae686 DQ |
820 | if (rc) { |
821 | printk(KERN_WARNING | |
822 | "%s: security_fs_use(%s) returned %d\n", | |
823 | __func__, sb->s_type->name, rc); | |
824 | goto out; | |
825 | } | |
c9180a57 | 826 | } |
aad82892 SF |
827 | |
828 | /* | |
01593d32 SS |
829 | * If this is a user namespace mount and the filesystem type is not |
830 | * explicitly whitelisted, then no contexts are allowed on the command | |
831 | * line and security labels must be ignored. | |
aad82892 | 832 | */ |
01593d32 SS |
833 | if (sb->s_user_ns != &init_user_ns && |
834 | strcmp(sb->s_type->name, "tmpfs") && | |
835 | strcmp(sb->s_type->name, "ramfs") && | |
836 | strcmp(sb->s_type->name, "devpts")) { | |
aad82892 SF |
837 | if (context_sid || fscontext_sid || rootcontext_sid || |
838 | defcontext_sid) { | |
839 | rc = -EACCES; | |
840 | goto out; | |
841 | } | |
842 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { | |
843 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; | |
844 | rc = security_transition_sid(current_sid(), current_sid(), | |
845 | SECCLASS_FILE, NULL, | |
846 | &sbsec->mntpoint_sid); | |
847 | if (rc) | |
848 | goto out; | |
849 | } | |
850 | goto out_set_opts; | |
851 | } | |
852 | ||
c9180a57 EP |
853 | /* sets the context of the superblock for the fs being mounted. */ |
854 | if (fscontext_sid) { | |
275bb41e | 855 | rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); |
1da177e4 | 856 | if (rc) |
c9180a57 | 857 | goto out; |
1da177e4 | 858 | |
c9180a57 | 859 | sbsec->sid = fscontext_sid; |
c312feb2 EP |
860 | } |
861 | ||
862 | /* | |
863 | * Switch to using mount point labeling behavior. | |
864 | * sets the label used on all file below the mountpoint, and will set | |
865 | * the superblock context if not already set. | |
866 | */ | |
eb9ae686 DQ |
867 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) { |
868 | sbsec->behavior = SECURITY_FS_USE_NATIVE; | |
869 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
870 | } | |
871 | ||
c9180a57 EP |
872 | if (context_sid) { |
873 | if (!fscontext_sid) { | |
275bb41e DH |
874 | rc = may_context_mount_sb_relabel(context_sid, sbsec, |
875 | cred); | |
b04ea3ce | 876 | if (rc) |
c9180a57 EP |
877 | goto out; |
878 | sbsec->sid = context_sid; | |
b04ea3ce | 879 | } else { |
275bb41e DH |
880 | rc = may_context_mount_inode_relabel(context_sid, sbsec, |
881 | cred); | |
b04ea3ce | 882 | if (rc) |
c9180a57 | 883 | goto out; |
b04ea3ce | 884 | } |
c9180a57 EP |
885 | if (!rootcontext_sid) |
886 | rootcontext_sid = context_sid; | |
1da177e4 | 887 | |
c9180a57 | 888 | sbsec->mntpoint_sid = context_sid; |
c312feb2 | 889 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; |
1da177e4 LT |
890 | } |
891 | ||
c9180a57 | 892 | if (rootcontext_sid) { |
275bb41e DH |
893 | rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, |
894 | cred); | |
0808925e | 895 | if (rc) |
c9180a57 | 896 | goto out; |
0808925e | 897 | |
c9180a57 | 898 | root_isec->sid = rootcontext_sid; |
6f3be9f5 | 899 | root_isec->initialized = LABEL_INITIALIZED; |
0808925e EP |
900 | } |
901 | ||
c9180a57 | 902 | if (defcontext_sid) { |
eb9ae686 DQ |
903 | if (sbsec->behavior != SECURITY_FS_USE_XATTR && |
904 | sbsec->behavior != SECURITY_FS_USE_NATIVE) { | |
c9180a57 EP |
905 | rc = -EINVAL; |
906 | printk(KERN_WARNING "SELinux: defcontext option is " | |
907 | "invalid for this filesystem type\n"); | |
908 | goto out; | |
1da177e4 LT |
909 | } |
910 | ||
c9180a57 EP |
911 | if (defcontext_sid != sbsec->def_sid) { |
912 | rc = may_context_mount_inode_relabel(defcontext_sid, | |
275bb41e | 913 | sbsec, cred); |
c9180a57 EP |
914 | if (rc) |
915 | goto out; | |
916 | } | |
1da177e4 | 917 | |
c9180a57 | 918 | sbsec->def_sid = defcontext_sid; |
1da177e4 LT |
919 | } |
920 | ||
aad82892 | 921 | out_set_opts: |
c9180a57 | 922 | rc = sb_finish_set_opts(sb); |
1da177e4 | 923 | out: |
c9180a57 | 924 | mutex_unlock(&sbsec->lock); |
1da177e4 | 925 | return rc; |
c9180a57 EP |
926 | out_double_mount: |
927 | rc = -EINVAL; | |
928 | printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " | |
29b1deb2 | 929 | "security settings for (dev %s, type %s)\n", sb->s_id, name); |
c9180a57 | 930 | goto out; |
1da177e4 LT |
931 | } |
932 | ||
094f7b69 JL |
933 | static int selinux_cmp_sb_context(const struct super_block *oldsb, |
934 | const struct super_block *newsb) | |
935 | { | |
936 | struct superblock_security_struct *old = oldsb->s_security; | |
937 | struct superblock_security_struct *new = newsb->s_security; | |
938 | char oldflags = old->flags & SE_MNTMASK; | |
939 | char newflags = new->flags & SE_MNTMASK; | |
940 | ||
941 | if (oldflags != newflags) | |
942 | goto mismatch; | |
943 | if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid) | |
944 | goto mismatch; | |
945 | if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid) | |
946 | goto mismatch; | |
947 | if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid) | |
948 | goto mismatch; | |
949 | if (oldflags & ROOTCONTEXT_MNT) { | |
83da53c5 AG |
950 | struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root); |
951 | struct inode_security_struct *newroot = backing_inode_security(newsb->s_root); | |
094f7b69 JL |
952 | if (oldroot->sid != newroot->sid) |
953 | goto mismatch; | |
954 | } | |
955 | return 0; | |
956 | mismatch: | |
957 | printk(KERN_WARNING "SELinux: mount invalid. Same superblock, " | |
958 | "different security settings for (dev %s, " | |
959 | "type %s)\n", newsb->s_id, newsb->s_type->name); | |
960 | return -EBUSY; | |
961 | } | |
962 | ||
963 | static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, | |
c9180a57 | 964 | struct super_block *newsb) |
1da177e4 | 965 | { |
c9180a57 EP |
966 | const struct superblock_security_struct *oldsbsec = oldsb->s_security; |
967 | struct superblock_security_struct *newsbsec = newsb->s_security; | |
1da177e4 | 968 | |
c9180a57 EP |
969 | int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); |
970 | int set_context = (oldsbsec->flags & CONTEXT_MNT); | |
971 | int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); | |
1da177e4 | 972 | |
0f5e6420 EP |
973 | /* |
974 | * if the parent was able to be mounted it clearly had no special lsm | |
e8c26255 | 975 | * mount options. thus we can safely deal with this superblock later |
0f5e6420 | 976 | */ |
e8c26255 | 977 | if (!ss_initialized) |
094f7b69 | 978 | return 0; |
c9180a57 | 979 | |
c9180a57 | 980 | /* how can we clone if the old one wasn't set up?? */ |
0d90a7ec | 981 | BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); |
c9180a57 | 982 | |
094f7b69 | 983 | /* if fs is reusing a sb, make sure that the contexts match */ |
0d90a7ec | 984 | if (newsbsec->flags & SE_SBINITIALIZED) |
094f7b69 | 985 | return selinux_cmp_sb_context(oldsb, newsb); |
5a552617 | 986 | |
c9180a57 EP |
987 | mutex_lock(&newsbsec->lock); |
988 | ||
989 | newsbsec->flags = oldsbsec->flags; | |
990 | ||
991 | newsbsec->sid = oldsbsec->sid; | |
992 | newsbsec->def_sid = oldsbsec->def_sid; | |
993 | newsbsec->behavior = oldsbsec->behavior; | |
994 | ||
995 | if (set_context) { | |
996 | u32 sid = oldsbsec->mntpoint_sid; | |
997 | ||
998 | if (!set_fscontext) | |
999 | newsbsec->sid = sid; | |
1000 | if (!set_rootcontext) { | |
83da53c5 | 1001 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); |
c9180a57 EP |
1002 | newisec->sid = sid; |
1003 | } | |
1004 | newsbsec->mntpoint_sid = sid; | |
1da177e4 | 1005 | } |
c9180a57 | 1006 | if (set_rootcontext) { |
83da53c5 AG |
1007 | const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root); |
1008 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); | |
1da177e4 | 1009 | |
c9180a57 | 1010 | newisec->sid = oldisec->sid; |
1da177e4 LT |
1011 | } |
1012 | ||
c9180a57 EP |
1013 | sb_finish_set_opts(newsb); |
1014 | mutex_unlock(&newsbsec->lock); | |
094f7b69 | 1015 | return 0; |
c9180a57 EP |
1016 | } |
1017 | ||
2e1479d9 AB |
1018 | static int selinux_parse_opts_str(char *options, |
1019 | struct security_mnt_opts *opts) | |
c9180a57 | 1020 | { |
e0007529 | 1021 | char *p; |
c9180a57 EP |
1022 | char *context = NULL, *defcontext = NULL; |
1023 | char *fscontext = NULL, *rootcontext = NULL; | |
e0007529 | 1024 | int rc, num_mnt_opts = 0; |
1da177e4 | 1025 | |
e0007529 | 1026 | opts->num_mnt_opts = 0; |
1da177e4 | 1027 | |
c9180a57 EP |
1028 | /* Standard string-based options. */ |
1029 | while ((p = strsep(&options, "|")) != NULL) { | |
1030 | int token; | |
1031 | substring_t args[MAX_OPT_ARGS]; | |
1da177e4 | 1032 | |
c9180a57 EP |
1033 | if (!*p) |
1034 | continue; | |
1da177e4 | 1035 | |
c9180a57 | 1036 | token = match_token(p, tokens, args); |
1da177e4 | 1037 | |
c9180a57 EP |
1038 | switch (token) { |
1039 | case Opt_context: | |
1040 | if (context || defcontext) { | |
1041 | rc = -EINVAL; | |
1042 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1043 | goto out_err; | |
1044 | } | |
1045 | context = match_strdup(&args[0]); | |
1046 | if (!context) { | |
1047 | rc = -ENOMEM; | |
1048 | goto out_err; | |
1049 | } | |
1050 | break; | |
1051 | ||
1052 | case Opt_fscontext: | |
1053 | if (fscontext) { | |
1054 | rc = -EINVAL; | |
1055 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1056 | goto out_err; | |
1057 | } | |
1058 | fscontext = match_strdup(&args[0]); | |
1059 | if (!fscontext) { | |
1060 | rc = -ENOMEM; | |
1061 | goto out_err; | |
1062 | } | |
1063 | break; | |
1064 | ||
1065 | case Opt_rootcontext: | |
1066 | if (rootcontext) { | |
1067 | rc = -EINVAL; | |
1068 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1069 | goto out_err; | |
1070 | } | |
1071 | rootcontext = match_strdup(&args[0]); | |
1072 | if (!rootcontext) { | |
1073 | rc = -ENOMEM; | |
1074 | goto out_err; | |
1075 | } | |
1076 | break; | |
1077 | ||
1078 | case Opt_defcontext: | |
1079 | if (context || defcontext) { | |
1080 | rc = -EINVAL; | |
1081 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1082 | goto out_err; | |
1083 | } | |
1084 | defcontext = match_strdup(&args[0]); | |
1085 | if (!defcontext) { | |
1086 | rc = -ENOMEM; | |
1087 | goto out_err; | |
1088 | } | |
1089 | break; | |
11689d47 DQ |
1090 | case Opt_labelsupport: |
1091 | break; | |
c9180a57 EP |
1092 | default: |
1093 | rc = -EINVAL; | |
1094 | printk(KERN_WARNING "SELinux: unknown mount option\n"); | |
1095 | goto out_err; | |
1da177e4 | 1096 | |
1da177e4 | 1097 | } |
1da177e4 | 1098 | } |
c9180a57 | 1099 | |
e0007529 | 1100 | rc = -ENOMEM; |
8931c3bd | 1101 | opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_KERNEL); |
e0007529 EP |
1102 | if (!opts->mnt_opts) |
1103 | goto out_err; | |
1104 | ||
8931c3bd TH |
1105 | opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), |
1106 | GFP_KERNEL); | |
e0007529 EP |
1107 | if (!opts->mnt_opts_flags) { |
1108 | kfree(opts->mnt_opts); | |
1109 | goto out_err; | |
1110 | } | |
1111 | ||
c9180a57 | 1112 | if (fscontext) { |
e0007529 EP |
1113 | opts->mnt_opts[num_mnt_opts] = fscontext; |
1114 | opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; | |
c9180a57 EP |
1115 | } |
1116 | if (context) { | |
e0007529 EP |
1117 | opts->mnt_opts[num_mnt_opts] = context; |
1118 | opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; | |
c9180a57 EP |
1119 | } |
1120 | if (rootcontext) { | |
e0007529 EP |
1121 | opts->mnt_opts[num_mnt_opts] = rootcontext; |
1122 | opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; | |
c9180a57 EP |
1123 | } |
1124 | if (defcontext) { | |
e0007529 EP |
1125 | opts->mnt_opts[num_mnt_opts] = defcontext; |
1126 | opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; | |
c9180a57 EP |
1127 | } |
1128 | ||
e0007529 EP |
1129 | opts->num_mnt_opts = num_mnt_opts; |
1130 | return 0; | |
1131 | ||
c9180a57 EP |
1132 | out_err: |
1133 | kfree(context); | |
1134 | kfree(defcontext); | |
1135 | kfree(fscontext); | |
1136 | kfree(rootcontext); | |
1da177e4 LT |
1137 | return rc; |
1138 | } | |
e0007529 EP |
1139 | /* |
1140 | * string mount options parsing and call set the sbsec | |
1141 | */ | |
1142 | static int superblock_doinit(struct super_block *sb, void *data) | |
1143 | { | |
1144 | int rc = 0; | |
1145 | char *options = data; | |
1146 | struct security_mnt_opts opts; | |
1147 | ||
1148 | security_init_mnt_opts(&opts); | |
1149 | ||
1150 | if (!data) | |
1151 | goto out; | |
1152 | ||
1153 | BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); | |
1154 | ||
1155 | rc = selinux_parse_opts_str(options, &opts); | |
1156 | if (rc) | |
1157 | goto out_err; | |
1158 | ||
1159 | out: | |
649f6e77 | 1160 | rc = selinux_set_mnt_opts(sb, &opts, 0, NULL); |
e0007529 EP |
1161 | |
1162 | out_err: | |
1163 | security_free_mnt_opts(&opts); | |
1164 | return rc; | |
1165 | } | |
1da177e4 | 1166 | |
3583a711 AB |
1167 | static void selinux_write_opts(struct seq_file *m, |
1168 | struct security_mnt_opts *opts) | |
2069f457 EP |
1169 | { |
1170 | int i; | |
1171 | char *prefix; | |
1172 | ||
1173 | for (i = 0; i < opts->num_mnt_opts; i++) { | |
11689d47 DQ |
1174 | char *has_comma; |
1175 | ||
1176 | if (opts->mnt_opts[i]) | |
1177 | has_comma = strchr(opts->mnt_opts[i], ','); | |
1178 | else | |
1179 | has_comma = NULL; | |
2069f457 EP |
1180 | |
1181 | switch (opts->mnt_opts_flags[i]) { | |
1182 | case CONTEXT_MNT: | |
1183 | prefix = CONTEXT_STR; | |
1184 | break; | |
1185 | case FSCONTEXT_MNT: | |
1186 | prefix = FSCONTEXT_STR; | |
1187 | break; | |
1188 | case ROOTCONTEXT_MNT: | |
1189 | prefix = ROOTCONTEXT_STR; | |
1190 | break; | |
1191 | case DEFCONTEXT_MNT: | |
1192 | prefix = DEFCONTEXT_STR; | |
1193 | break; | |
12f348b9 | 1194 | case SBLABEL_MNT: |
11689d47 DQ |
1195 | seq_putc(m, ','); |
1196 | seq_puts(m, LABELSUPP_STR); | |
1197 | continue; | |
2069f457 EP |
1198 | default: |
1199 | BUG(); | |
a35c6c83 | 1200 | return; |
2069f457 EP |
1201 | }; |
1202 | /* we need a comma before each option */ | |
1203 | seq_putc(m, ','); | |
1204 | seq_puts(m, prefix); | |
1205 | if (has_comma) | |
1206 | seq_putc(m, '\"'); | |
a068acf2 | 1207 | seq_escape(m, opts->mnt_opts[i], "\"\n\\"); |
2069f457 EP |
1208 | if (has_comma) |
1209 | seq_putc(m, '\"'); | |
1210 | } | |
1211 | } | |
1212 | ||
1213 | static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) | |
1214 | { | |
1215 | struct security_mnt_opts opts; | |
1216 | int rc; | |
1217 | ||
1218 | rc = selinux_get_mnt_opts(sb, &opts); | |
383795c2 EP |
1219 | if (rc) { |
1220 | /* before policy load we may get EINVAL, don't show anything */ | |
1221 | if (rc == -EINVAL) | |
1222 | rc = 0; | |
2069f457 | 1223 | return rc; |
383795c2 | 1224 | } |
2069f457 EP |
1225 | |
1226 | selinux_write_opts(m, &opts); | |
1227 | ||
1228 | security_free_mnt_opts(&opts); | |
1229 | ||
1230 | return rc; | |
1231 | } | |
1232 | ||
1da177e4 LT |
1233 | static inline u16 inode_mode_to_security_class(umode_t mode) |
1234 | { | |
1235 | switch (mode & S_IFMT) { | |
1236 | case S_IFSOCK: | |
1237 | return SECCLASS_SOCK_FILE; | |
1238 | case S_IFLNK: | |
1239 | return SECCLASS_LNK_FILE; | |
1240 | case S_IFREG: | |
1241 | return SECCLASS_FILE; | |
1242 | case S_IFBLK: | |
1243 | return SECCLASS_BLK_FILE; | |
1244 | case S_IFDIR: | |
1245 | return SECCLASS_DIR; | |
1246 | case S_IFCHR: | |
1247 | return SECCLASS_CHR_FILE; | |
1248 | case S_IFIFO: | |
1249 | return SECCLASS_FIFO_FILE; | |
1250 | ||
1251 | } | |
1252 | ||
1253 | return SECCLASS_FILE; | |
1254 | } | |
1255 | ||
13402580 JM |
1256 | static inline int default_protocol_stream(int protocol) |
1257 | { | |
1258 | return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); | |
1259 | } | |
1260 | ||
1261 | static inline int default_protocol_dgram(int protocol) | |
1262 | { | |
1263 | return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); | |
1264 | } | |
1265 | ||
1da177e4 LT |
1266 | static inline u16 socket_type_to_security_class(int family, int type, int protocol) |
1267 | { | |
da69a530 SS |
1268 | int extsockclass = selinux_policycap_extsockclass; |
1269 | ||
1da177e4 LT |
1270 | switch (family) { |
1271 | case PF_UNIX: | |
1272 | switch (type) { | |
1273 | case SOCK_STREAM: | |
1274 | case SOCK_SEQPACKET: | |
1275 | return SECCLASS_UNIX_STREAM_SOCKET; | |
1276 | case SOCK_DGRAM: | |
1277 | return SECCLASS_UNIX_DGRAM_SOCKET; | |
1278 | } | |
1279 | break; | |
1280 | case PF_INET: | |
1281 | case PF_INET6: | |
1282 | switch (type) { | |
1283 | case SOCK_STREAM: | |
da69a530 | 1284 | case SOCK_SEQPACKET: |
13402580 JM |
1285 | if (default_protocol_stream(protocol)) |
1286 | return SECCLASS_TCP_SOCKET; | |
da69a530 SS |
1287 | else if (extsockclass && protocol == IPPROTO_SCTP) |
1288 | return SECCLASS_SCTP_SOCKET; | |
13402580 JM |
1289 | else |
1290 | return SECCLASS_RAWIP_SOCKET; | |
1da177e4 | 1291 | case SOCK_DGRAM: |
13402580 JM |
1292 | if (default_protocol_dgram(protocol)) |
1293 | return SECCLASS_UDP_SOCKET; | |
ef37979a SS |
1294 | else if (extsockclass && (protocol == IPPROTO_ICMP || |
1295 | protocol == IPPROTO_ICMPV6)) | |
da69a530 | 1296 | return SECCLASS_ICMP_SOCKET; |
13402580 JM |
1297 | else |
1298 | return SECCLASS_RAWIP_SOCKET; | |
2ee92d46 JM |
1299 | case SOCK_DCCP: |
1300 | return SECCLASS_DCCP_SOCKET; | |
13402580 | 1301 | default: |
1da177e4 LT |
1302 | return SECCLASS_RAWIP_SOCKET; |
1303 | } | |
1304 | break; | |
1305 | case PF_NETLINK: | |
1306 | switch (protocol) { | |
1307 | case NETLINK_ROUTE: | |
1308 | return SECCLASS_NETLINK_ROUTE_SOCKET; | |
7f1fb60c | 1309 | case NETLINK_SOCK_DIAG: |
1da177e4 LT |
1310 | return SECCLASS_NETLINK_TCPDIAG_SOCKET; |
1311 | case NETLINK_NFLOG: | |
1312 | return SECCLASS_NETLINK_NFLOG_SOCKET; | |
1313 | case NETLINK_XFRM: | |
1314 | return SECCLASS_NETLINK_XFRM_SOCKET; | |
1315 | case NETLINK_SELINUX: | |
1316 | return SECCLASS_NETLINK_SELINUX_SOCKET; | |
6c6d2e9b SS |
1317 | case NETLINK_ISCSI: |
1318 | return SECCLASS_NETLINK_ISCSI_SOCKET; | |
1da177e4 LT |
1319 | case NETLINK_AUDIT: |
1320 | return SECCLASS_NETLINK_AUDIT_SOCKET; | |
6c6d2e9b SS |
1321 | case NETLINK_FIB_LOOKUP: |
1322 | return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET; | |
1323 | case NETLINK_CONNECTOR: | |
1324 | return SECCLASS_NETLINK_CONNECTOR_SOCKET; | |
1325 | case NETLINK_NETFILTER: | |
1326 | return SECCLASS_NETLINK_NETFILTER_SOCKET; | |
1da177e4 LT |
1327 | case NETLINK_DNRTMSG: |
1328 | return SECCLASS_NETLINK_DNRT_SOCKET; | |
0c9b7942 JM |
1329 | case NETLINK_KOBJECT_UEVENT: |
1330 | return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; | |
6c6d2e9b SS |
1331 | case NETLINK_GENERIC: |
1332 | return SECCLASS_NETLINK_GENERIC_SOCKET; | |
1333 | case NETLINK_SCSITRANSPORT: | |
1334 | return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET; | |
1335 | case NETLINK_RDMA: | |
1336 | return SECCLASS_NETLINK_RDMA_SOCKET; | |
1337 | case NETLINK_CRYPTO: | |
1338 | return SECCLASS_NETLINK_CRYPTO_SOCKET; | |
1da177e4 LT |
1339 | default: |
1340 | return SECCLASS_NETLINK_SOCKET; | |
1341 | } | |
1342 | case PF_PACKET: | |
1343 | return SECCLASS_PACKET_SOCKET; | |
1344 | case PF_KEY: | |
1345 | return SECCLASS_KEY_SOCKET; | |
3e3ff15e CP |
1346 | case PF_APPLETALK: |
1347 | return SECCLASS_APPLETALK_SOCKET; | |
1da177e4 LT |
1348 | } |
1349 | ||
da69a530 SS |
1350 | if (extsockclass) { |
1351 | switch (family) { | |
1352 | case PF_AX25: | |
1353 | return SECCLASS_AX25_SOCKET; | |
1354 | case PF_IPX: | |
1355 | return SECCLASS_IPX_SOCKET; | |
1356 | case PF_NETROM: | |
1357 | return SECCLASS_NETROM_SOCKET; | |
da69a530 SS |
1358 | case PF_ATMPVC: |
1359 | return SECCLASS_ATMPVC_SOCKET; | |
1360 | case PF_X25: | |
1361 | return SECCLASS_X25_SOCKET; | |
1362 | case PF_ROSE: | |
1363 | return SECCLASS_ROSE_SOCKET; | |
1364 | case PF_DECnet: | |
1365 | return SECCLASS_DECNET_SOCKET; | |
1366 | case PF_ATMSVC: | |
1367 | return SECCLASS_ATMSVC_SOCKET; | |
1368 | case PF_RDS: | |
1369 | return SECCLASS_RDS_SOCKET; | |
1370 | case PF_IRDA: | |
1371 | return SECCLASS_IRDA_SOCKET; | |
1372 | case PF_PPPOX: | |
1373 | return SECCLASS_PPPOX_SOCKET; | |
1374 | case PF_LLC: | |
1375 | return SECCLASS_LLC_SOCKET; | |
da69a530 SS |
1376 | case PF_CAN: |
1377 | return SECCLASS_CAN_SOCKET; | |
1378 | case PF_TIPC: | |
1379 | return SECCLASS_TIPC_SOCKET; | |
1380 | case PF_BLUETOOTH: | |
1381 | return SECCLASS_BLUETOOTH_SOCKET; | |
1382 | case PF_IUCV: | |
1383 | return SECCLASS_IUCV_SOCKET; | |
1384 | case PF_RXRPC: | |
1385 | return SECCLASS_RXRPC_SOCKET; | |
1386 | case PF_ISDN: | |
1387 | return SECCLASS_ISDN_SOCKET; | |
1388 | case PF_PHONET: | |
1389 | return SECCLASS_PHONET_SOCKET; | |
1390 | case PF_IEEE802154: | |
1391 | return SECCLASS_IEEE802154_SOCKET; | |
1392 | case PF_CAIF: | |
1393 | return SECCLASS_CAIF_SOCKET; | |
1394 | case PF_ALG: | |
1395 | return SECCLASS_ALG_SOCKET; | |
1396 | case PF_NFC: | |
1397 | return SECCLASS_NFC_SOCKET; | |
1398 | case PF_VSOCK: | |
1399 | return SECCLASS_VSOCK_SOCKET; | |
1400 | case PF_KCM: | |
1401 | return SECCLASS_KCM_SOCKET; | |
1402 | case PF_QIPCRTR: | |
1403 | return SECCLASS_QIPCRTR_SOCKET; | |
3051bf36 LT |
1404 | case PF_SMC: |
1405 | return SECCLASS_SMC_SOCKET; | |
1406 | #if PF_MAX > 44 | |
da69a530 SS |
1407 | #error New address family defined, please update this function. |
1408 | #endif | |
1409 | } | |
1410 | } | |
1411 | ||
1da177e4 LT |
1412 | return SECCLASS_SOCKET; |
1413 | } | |
1414 | ||
134509d5 SS |
1415 | static int selinux_genfs_get_sid(struct dentry *dentry, |
1416 | u16 tclass, | |
1417 | u16 flags, | |
1418 | u32 *sid) | |
1da177e4 | 1419 | { |
8e6c9693 | 1420 | int rc; |
fc64005c | 1421 | struct super_block *sb = dentry->d_sb; |
8e6c9693 | 1422 | char *buffer, *path; |
1da177e4 | 1423 | |
828dfe1d | 1424 | buffer = (char *)__get_free_page(GFP_KERNEL); |
1da177e4 LT |
1425 | if (!buffer) |
1426 | return -ENOMEM; | |
1427 | ||
8e6c9693 LAG |
1428 | path = dentry_path_raw(dentry, buffer, PAGE_SIZE); |
1429 | if (IS_ERR(path)) | |
1430 | rc = PTR_ERR(path); | |
1431 | else { | |
134509d5 SS |
1432 | if (flags & SE_SBPROC) { |
1433 | /* each process gets a /proc/PID/ entry. Strip off the | |
1434 | * PID part to get a valid selinux labeling. | |
1435 | * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ | |
1436 | while (path[1] >= '0' && path[1] <= '9') { | |
1437 | path[1] = '/'; | |
1438 | path++; | |
1439 | } | |
8e6c9693 | 1440 | } |
134509d5 | 1441 | rc = security_genfs_sid(sb->s_type->name, path, tclass, sid); |
1da177e4 | 1442 | } |
1da177e4 LT |
1443 | free_page((unsigned long)buffer); |
1444 | return rc; | |
1445 | } | |
1da177e4 LT |
1446 | |
1447 | /* The inode's security attributes must be initialized before first use. */ | |
1448 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) | |
1449 | { | |
1450 | struct superblock_security_struct *sbsec = NULL; | |
1451 | struct inode_security_struct *isec = inode->i_security; | |
9287aed2 AG |
1452 | u32 task_sid, sid = 0; |
1453 | u16 sclass; | |
1da177e4 LT |
1454 | struct dentry *dentry; |
1455 | #define INITCONTEXTLEN 255 | |
1456 | char *context = NULL; | |
1457 | unsigned len = 0; | |
1458 | int rc = 0; | |
1da177e4 | 1459 | |
6f3be9f5 | 1460 | if (isec->initialized == LABEL_INITIALIZED) |
13457d07 | 1461 | return 0; |
1da177e4 | 1462 | |
9287aed2 | 1463 | spin_lock(&isec->lock); |
6f3be9f5 | 1464 | if (isec->initialized == LABEL_INITIALIZED) |
23970741 | 1465 | goto out_unlock; |
1da177e4 | 1466 | |
13457d07 AG |
1467 | if (isec->sclass == SECCLASS_FILE) |
1468 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
1469 | ||
1da177e4 | 1470 | sbsec = inode->i_sb->s_security; |
0d90a7ec | 1471 | if (!(sbsec->flags & SE_SBINITIALIZED)) { |
1da177e4 LT |
1472 | /* Defer initialization until selinux_complete_init, |
1473 | after the initial policy is loaded and the security | |
1474 | server is ready to handle calls. */ | |
1475 | spin_lock(&sbsec->isec_lock); | |
1476 | if (list_empty(&isec->list)) | |
1477 | list_add(&isec->list, &sbsec->isec_head); | |
1478 | spin_unlock(&sbsec->isec_lock); | |
23970741 | 1479 | goto out_unlock; |
1da177e4 LT |
1480 | } |
1481 | ||
9287aed2 AG |
1482 | sclass = isec->sclass; |
1483 | task_sid = isec->task_sid; | |
1484 | sid = isec->sid; | |
1485 | isec->initialized = LABEL_PENDING; | |
1486 | spin_unlock(&isec->lock); | |
1487 | ||
1da177e4 | 1488 | switch (sbsec->behavior) { |
eb9ae686 DQ |
1489 | case SECURITY_FS_USE_NATIVE: |
1490 | break; | |
1da177e4 | 1491 | case SECURITY_FS_USE_XATTR: |
5d6c3191 | 1492 | if (!(inode->i_opflags & IOP_XATTR)) { |
9287aed2 | 1493 | sid = sbsec->def_sid; |
1da177e4 LT |
1494 | break; |
1495 | } | |
1da177e4 LT |
1496 | /* Need a dentry, since the xattr API requires one. |
1497 | Life would be simpler if we could just pass the inode. */ | |
1498 | if (opt_dentry) { | |
1499 | /* Called from d_instantiate or d_splice_alias. */ | |
1500 | dentry = dget(opt_dentry); | |
1501 | } else { | |
1502 | /* Called from selinux_complete_init, try to find a dentry. */ | |
1503 | dentry = d_find_alias(inode); | |
1504 | } | |
1505 | if (!dentry) { | |
df7f54c0 EP |
1506 | /* |
1507 | * this is can be hit on boot when a file is accessed | |
1508 | * before the policy is loaded. When we load policy we | |
1509 | * may find inodes that have no dentry on the | |
1510 | * sbsec->isec_head list. No reason to complain as these | |
1511 | * will get fixed up the next time we go through | |
1512 | * inode_doinit with a dentry, before these inodes could | |
1513 | * be used again by userspace. | |
1514 | */ | |
9287aed2 | 1515 | goto out; |
1da177e4 LT |
1516 | } |
1517 | ||
1518 | len = INITCONTEXTLEN; | |
4cb912f1 | 1519 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1520 | if (!context) { |
1521 | rc = -ENOMEM; | |
1522 | dput(dentry); | |
9287aed2 | 1523 | goto out; |
1da177e4 | 1524 | } |
4cb912f1 | 1525 | context[len] = '\0'; |
5d6c3191 | 1526 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 | 1527 | if (rc == -ERANGE) { |
314dabb8 JM |
1528 | kfree(context); |
1529 | ||
1da177e4 | 1530 | /* Need a larger buffer. Query for the right size. */ |
5d6c3191 | 1531 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0); |
1da177e4 LT |
1532 | if (rc < 0) { |
1533 | dput(dentry); | |
9287aed2 | 1534 | goto out; |
1da177e4 | 1535 | } |
1da177e4 | 1536 | len = rc; |
4cb912f1 | 1537 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1538 | if (!context) { |
1539 | rc = -ENOMEM; | |
1540 | dput(dentry); | |
9287aed2 | 1541 | goto out; |
1da177e4 | 1542 | } |
4cb912f1 | 1543 | context[len] = '\0'; |
5d6c3191 | 1544 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 LT |
1545 | } |
1546 | dput(dentry); | |
1547 | if (rc < 0) { | |
1548 | if (rc != -ENODATA) { | |
744ba35e | 1549 | printk(KERN_WARNING "SELinux: %s: getxattr returned " |
dd6f953a | 1550 | "%d for dev=%s ino=%ld\n", __func__, |
1da177e4 LT |
1551 | -rc, inode->i_sb->s_id, inode->i_ino); |
1552 | kfree(context); | |
9287aed2 | 1553 | goto out; |
1da177e4 LT |
1554 | } |
1555 | /* Map ENODATA to the default file SID */ | |
1556 | sid = sbsec->def_sid; | |
1557 | rc = 0; | |
1558 | } else { | |
f5c1d5b2 | 1559 | rc = security_context_to_sid_default(context, rc, &sid, |
869ab514 SS |
1560 | sbsec->def_sid, |
1561 | GFP_NOFS); | |
1da177e4 | 1562 | if (rc) { |
4ba0a8ad EP |
1563 | char *dev = inode->i_sb->s_id; |
1564 | unsigned long ino = inode->i_ino; | |
1565 | ||
1566 | if (rc == -EINVAL) { | |
1567 | if (printk_ratelimit()) | |
1568 | printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " | |
1569 | "context=%s. This indicates you may need to relabel the inode or the " | |
1570 | "filesystem in question.\n", ino, dev, context); | |
1571 | } else { | |
1572 | printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " | |
1573 | "returned %d for dev=%s ino=%ld\n", | |
1574 | __func__, context, -rc, dev, ino); | |
1575 | } | |
1da177e4 LT |
1576 | kfree(context); |
1577 | /* Leave with the unlabeled SID */ | |
1578 | rc = 0; | |
1579 | break; | |
1580 | } | |
1581 | } | |
1582 | kfree(context); | |
1da177e4 LT |
1583 | break; |
1584 | case SECURITY_FS_USE_TASK: | |
9287aed2 | 1585 | sid = task_sid; |
1da177e4 LT |
1586 | break; |
1587 | case SECURITY_FS_USE_TRANS: | |
1588 | /* Default to the fs SID. */ | |
9287aed2 | 1589 | sid = sbsec->sid; |
1da177e4 LT |
1590 | |
1591 | /* Try to obtain a transition SID. */ | |
9287aed2 | 1592 | rc = security_transition_sid(task_sid, sid, sclass, NULL, &sid); |
1da177e4 | 1593 | if (rc) |
9287aed2 | 1594 | goto out; |
1da177e4 | 1595 | break; |
c312feb2 | 1596 | case SECURITY_FS_USE_MNTPOINT: |
9287aed2 | 1597 | sid = sbsec->mntpoint_sid; |
c312feb2 | 1598 | break; |
1da177e4 | 1599 | default: |
c312feb2 | 1600 | /* Default to the fs superblock SID. */ |
9287aed2 | 1601 | sid = sbsec->sid; |
1da177e4 | 1602 | |
134509d5 | 1603 | if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) { |
f64410ec PM |
1604 | /* We must have a dentry to determine the label on |
1605 | * procfs inodes */ | |
1606 | if (opt_dentry) | |
1607 | /* Called from d_instantiate or | |
1608 | * d_splice_alias. */ | |
1609 | dentry = dget(opt_dentry); | |
1610 | else | |
1611 | /* Called from selinux_complete_init, try to | |
1612 | * find a dentry. */ | |
1613 | dentry = d_find_alias(inode); | |
1614 | /* | |
1615 | * This can be hit on boot when a file is accessed | |
1616 | * before the policy is loaded. When we load policy we | |
1617 | * may find inodes that have no dentry on the | |
1618 | * sbsec->isec_head list. No reason to complain as | |
1619 | * these will get fixed up the next time we go through | |
1620 | * inode_doinit() with a dentry, before these inodes | |
1621 | * could be used again by userspace. | |
1622 | */ | |
1623 | if (!dentry) | |
9287aed2 AG |
1624 | goto out; |
1625 | rc = selinux_genfs_get_sid(dentry, sclass, | |
134509d5 | 1626 | sbsec->flags, &sid); |
f64410ec PM |
1627 | dput(dentry); |
1628 | if (rc) | |
9287aed2 | 1629 | goto out; |
1da177e4 LT |
1630 | } |
1631 | break; | |
1632 | } | |
1633 | ||
9287aed2 AG |
1634 | out: |
1635 | spin_lock(&isec->lock); | |
1636 | if (isec->initialized == LABEL_PENDING) { | |
1637 | if (!sid || rc) { | |
1638 | isec->initialized = LABEL_INVALID; | |
1639 | goto out_unlock; | |
1640 | } | |
1641 | ||
1642 | isec->initialized = LABEL_INITIALIZED; | |
1643 | isec->sid = sid; | |
1644 | } | |
1da177e4 | 1645 | |
23970741 | 1646 | out_unlock: |
9287aed2 | 1647 | spin_unlock(&isec->lock); |
1da177e4 LT |
1648 | return rc; |
1649 | } | |
1650 | ||
1651 | /* Convert a Linux signal to an access vector. */ | |
1652 | static inline u32 signal_to_av(int sig) | |
1653 | { | |
1654 | u32 perm = 0; | |
1655 | ||
1656 | switch (sig) { | |
1657 | case SIGCHLD: | |
1658 | /* Commonly granted from child to parent. */ | |
1659 | perm = PROCESS__SIGCHLD; | |
1660 | break; | |
1661 | case SIGKILL: | |
1662 | /* Cannot be caught or ignored */ | |
1663 | perm = PROCESS__SIGKILL; | |
1664 | break; | |
1665 | case SIGSTOP: | |
1666 | /* Cannot be caught or ignored */ | |
1667 | perm = PROCESS__SIGSTOP; | |
1668 | break; | |
1669 | default: | |
1670 | /* All other signals. */ | |
1671 | perm = PROCESS__SIGNAL; | |
1672 | break; | |
1673 | } | |
1674 | ||
1675 | return perm; | |
1676 | } | |
1677 | ||
b68e418c SS |
1678 | #if CAP_LAST_CAP > 63 |
1679 | #error Fix SELinux to handle capabilities > 63. | |
1680 | #endif | |
1681 | ||
1da177e4 | 1682 | /* Check whether a task is allowed to use a capability. */ |
6a9de491 | 1683 | static int cred_has_capability(const struct cred *cred, |
8e4ff6f2 | 1684 | int cap, int audit, bool initns) |
1da177e4 | 1685 | { |
2bf49690 | 1686 | struct common_audit_data ad; |
06112163 | 1687 | struct av_decision avd; |
b68e418c | 1688 | u16 sclass; |
3699c53c | 1689 | u32 sid = cred_sid(cred); |
b68e418c | 1690 | u32 av = CAP_TO_MASK(cap); |
06112163 | 1691 | int rc; |
1da177e4 | 1692 | |
50c205f5 | 1693 | ad.type = LSM_AUDIT_DATA_CAP; |
1da177e4 LT |
1694 | ad.u.cap = cap; |
1695 | ||
b68e418c SS |
1696 | switch (CAP_TO_INDEX(cap)) { |
1697 | case 0: | |
8e4ff6f2 | 1698 | sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS; |
b68e418c SS |
1699 | break; |
1700 | case 1: | |
8e4ff6f2 | 1701 | sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS; |
b68e418c SS |
1702 | break; |
1703 | default: | |
1704 | printk(KERN_ERR | |
1705 | "SELinux: out of range capability %d\n", cap); | |
1706 | BUG(); | |
a35c6c83 | 1707 | return -EINVAL; |
b68e418c | 1708 | } |
06112163 | 1709 | |
275bb41e | 1710 | rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); |
9ade0cf4 | 1711 | if (audit == SECURITY_CAP_AUDIT) { |
7b20ea25 | 1712 | int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0); |
9ade0cf4 EP |
1713 | if (rc2) |
1714 | return rc2; | |
1715 | } | |
06112163 | 1716 | return rc; |
1da177e4 LT |
1717 | } |
1718 | ||
1da177e4 LT |
1719 | /* Check whether a task has a particular permission to an inode. |
1720 | The 'adp' parameter is optional and allows other audit | |
1721 | data to be passed (e.g. the dentry). */ | |
88e67f3b | 1722 | static int inode_has_perm(const struct cred *cred, |
1da177e4 LT |
1723 | struct inode *inode, |
1724 | u32 perms, | |
19e49834 | 1725 | struct common_audit_data *adp) |
1da177e4 | 1726 | { |
1da177e4 | 1727 | struct inode_security_struct *isec; |
275bb41e | 1728 | u32 sid; |
1da177e4 | 1729 | |
e0e81739 DH |
1730 | validate_creds(cred); |
1731 | ||
828dfe1d | 1732 | if (unlikely(IS_PRIVATE(inode))) |
bbaca6c2 SS |
1733 | return 0; |
1734 | ||
88e67f3b | 1735 | sid = cred_sid(cred); |
1da177e4 LT |
1736 | isec = inode->i_security; |
1737 | ||
19e49834 | 1738 | return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp); |
1da177e4 LT |
1739 | } |
1740 | ||
1741 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1742 | the dentry to help the auditing code to more easily generate the | |
1743 | pathname if needed. */ | |
88e67f3b | 1744 | static inline int dentry_has_perm(const struct cred *cred, |
1da177e4 LT |
1745 | struct dentry *dentry, |
1746 | u32 av) | |
1747 | { | |
c6f493d6 | 1748 | struct inode *inode = d_backing_inode(dentry); |
2bf49690 | 1749 | struct common_audit_data ad; |
88e67f3b | 1750 | |
50c205f5 | 1751 | ad.type = LSM_AUDIT_DATA_DENTRY; |
2875fa00 | 1752 | ad.u.dentry = dentry; |
5d226df4 | 1753 | __inode_security_revalidate(inode, dentry, true); |
19e49834 | 1754 | return inode_has_perm(cred, inode, av, &ad); |
2875fa00 EP |
1755 | } |
1756 | ||
1757 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1758 | the path to help the auditing code to more easily generate the | |
1759 | pathname if needed. */ | |
1760 | static inline int path_has_perm(const struct cred *cred, | |
3f7036a0 | 1761 | const struct path *path, |
2875fa00 EP |
1762 | u32 av) |
1763 | { | |
c6f493d6 | 1764 | struct inode *inode = d_backing_inode(path->dentry); |
2875fa00 EP |
1765 | struct common_audit_data ad; |
1766 | ||
50c205f5 | 1767 | ad.type = LSM_AUDIT_DATA_PATH; |
2875fa00 | 1768 | ad.u.path = *path; |
5d226df4 | 1769 | __inode_security_revalidate(inode, path->dentry, true); |
19e49834 | 1770 | return inode_has_perm(cred, inode, av, &ad); |
1da177e4 LT |
1771 | } |
1772 | ||
13f8e981 DH |
1773 | /* Same as path_has_perm, but uses the inode from the file struct. */ |
1774 | static inline int file_path_has_perm(const struct cred *cred, | |
1775 | struct file *file, | |
1776 | u32 av) | |
1777 | { | |
1778 | struct common_audit_data ad; | |
1779 | ||
43af5de7 VG |
1780 | ad.type = LSM_AUDIT_DATA_FILE; |
1781 | ad.u.file = file; | |
19e49834 | 1782 | return inode_has_perm(cred, file_inode(file), av, &ad); |
13f8e981 DH |
1783 | } |
1784 | ||
1da177e4 LT |
1785 | /* Check whether a task can use an open file descriptor to |
1786 | access an inode in a given way. Check access to the | |
1787 | descriptor itself, and then use dentry_has_perm to | |
1788 | check a particular permission to the file. | |
1789 | Access to the descriptor is implicitly granted if it | |
1790 | has the same SID as the process. If av is zero, then | |
1791 | access to the file is not checked, e.g. for cases | |
1792 | where only the descriptor is affected like seek. */ | |
88e67f3b DH |
1793 | static int file_has_perm(const struct cred *cred, |
1794 | struct file *file, | |
1795 | u32 av) | |
1da177e4 | 1796 | { |
1da177e4 | 1797 | struct file_security_struct *fsec = file->f_security; |
496ad9aa | 1798 | struct inode *inode = file_inode(file); |
2bf49690 | 1799 | struct common_audit_data ad; |
88e67f3b | 1800 | u32 sid = cred_sid(cred); |
1da177e4 LT |
1801 | int rc; |
1802 | ||
43af5de7 VG |
1803 | ad.type = LSM_AUDIT_DATA_FILE; |
1804 | ad.u.file = file; | |
1da177e4 | 1805 | |
275bb41e DH |
1806 | if (sid != fsec->sid) { |
1807 | rc = avc_has_perm(sid, fsec->sid, | |
1da177e4 LT |
1808 | SECCLASS_FD, |
1809 | FD__USE, | |
1810 | &ad); | |
1811 | if (rc) | |
88e67f3b | 1812 | goto out; |
1da177e4 LT |
1813 | } |
1814 | ||
1815 | /* av is zero if only checking access to the descriptor. */ | |
88e67f3b | 1816 | rc = 0; |
1da177e4 | 1817 | if (av) |
19e49834 | 1818 | rc = inode_has_perm(cred, inode, av, &ad); |
1da177e4 | 1819 | |
88e67f3b DH |
1820 | out: |
1821 | return rc; | |
1da177e4 LT |
1822 | } |
1823 | ||
c3c188b2 DH |
1824 | /* |
1825 | * Determine the label for an inode that might be unioned. | |
1826 | */ | |
c957f6df VG |
1827 | static int |
1828 | selinux_determine_inode_label(const struct task_security_struct *tsec, | |
1829 | struct inode *dir, | |
1830 | const struct qstr *name, u16 tclass, | |
1831 | u32 *_new_isid) | |
c3c188b2 DH |
1832 | { |
1833 | const struct superblock_security_struct *sbsec = dir->i_sb->s_security; | |
c3c188b2 DH |
1834 | |
1835 | if ((sbsec->flags & SE_SBINITIALIZED) && | |
1836 | (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { | |
1837 | *_new_isid = sbsec->mntpoint_sid; | |
1838 | } else if ((sbsec->flags & SBLABEL_MNT) && | |
1839 | tsec->create_sid) { | |
1840 | *_new_isid = tsec->create_sid; | |
1841 | } else { | |
20cdef8d | 1842 | const struct inode_security_struct *dsec = inode_security(dir); |
c3c188b2 DH |
1843 | return security_transition_sid(tsec->sid, dsec->sid, tclass, |
1844 | name, _new_isid); | |
1845 | } | |
1846 | ||
1847 | return 0; | |
1848 | } | |
1849 | ||
1da177e4 LT |
1850 | /* Check whether a task can create a file. */ |
1851 | static int may_create(struct inode *dir, | |
1852 | struct dentry *dentry, | |
1853 | u16 tclass) | |
1854 | { | |
5fb49870 | 1855 | const struct task_security_struct *tsec = current_security(); |
1da177e4 LT |
1856 | struct inode_security_struct *dsec; |
1857 | struct superblock_security_struct *sbsec; | |
275bb41e | 1858 | u32 sid, newsid; |
2bf49690 | 1859 | struct common_audit_data ad; |
1da177e4 LT |
1860 | int rc; |
1861 | ||
83da53c5 | 1862 | dsec = inode_security(dir); |
1da177e4 LT |
1863 | sbsec = dir->i_sb->s_security; |
1864 | ||
275bb41e | 1865 | sid = tsec->sid; |
275bb41e | 1866 | |
50c205f5 | 1867 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1868 | ad.u.dentry = dentry; |
1da177e4 | 1869 | |
275bb41e | 1870 | rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, |
1da177e4 LT |
1871 | DIR__ADD_NAME | DIR__SEARCH, |
1872 | &ad); | |
1873 | if (rc) | |
1874 | return rc; | |
1875 | ||
c957f6df VG |
1876 | rc = selinux_determine_inode_label(current_security(), dir, |
1877 | &dentry->d_name, tclass, &newsid); | |
c3c188b2 DH |
1878 | if (rc) |
1879 | return rc; | |
1da177e4 | 1880 | |
275bb41e | 1881 | rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); |
1da177e4 LT |
1882 | if (rc) |
1883 | return rc; | |
1884 | ||
1885 | return avc_has_perm(newsid, sbsec->sid, | |
1886 | SECCLASS_FILESYSTEM, | |
1887 | FILESYSTEM__ASSOCIATE, &ad); | |
1888 | } | |
1889 | ||
828dfe1d EP |
1890 | #define MAY_LINK 0 |
1891 | #define MAY_UNLINK 1 | |
1892 | #define MAY_RMDIR 2 | |
1da177e4 LT |
1893 | |
1894 | /* Check whether a task can link, unlink, or rmdir a file/directory. */ | |
1895 | static int may_link(struct inode *dir, | |
1896 | struct dentry *dentry, | |
1897 | int kind) | |
1898 | ||
1899 | { | |
1da177e4 | 1900 | struct inode_security_struct *dsec, *isec; |
2bf49690 | 1901 | struct common_audit_data ad; |
275bb41e | 1902 | u32 sid = current_sid(); |
1da177e4 LT |
1903 | u32 av; |
1904 | int rc; | |
1905 | ||
83da53c5 AG |
1906 | dsec = inode_security(dir); |
1907 | isec = backing_inode_security(dentry); | |
1da177e4 | 1908 | |
50c205f5 | 1909 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1910 | ad.u.dentry = dentry; |
1da177e4 LT |
1911 | |
1912 | av = DIR__SEARCH; | |
1913 | av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); | |
275bb41e | 1914 | rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); |
1da177e4 LT |
1915 | if (rc) |
1916 | return rc; | |
1917 | ||
1918 | switch (kind) { | |
1919 | case MAY_LINK: | |
1920 | av = FILE__LINK; | |
1921 | break; | |
1922 | case MAY_UNLINK: | |
1923 | av = FILE__UNLINK; | |
1924 | break; | |
1925 | case MAY_RMDIR: | |
1926 | av = DIR__RMDIR; | |
1927 | break; | |
1928 | default: | |
744ba35e EP |
1929 | printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", |
1930 | __func__, kind); | |
1da177e4 LT |
1931 | return 0; |
1932 | } | |
1933 | ||
275bb41e | 1934 | rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); |
1da177e4 LT |
1935 | return rc; |
1936 | } | |
1937 | ||
1938 | static inline int may_rename(struct inode *old_dir, | |
1939 | struct dentry *old_dentry, | |
1940 | struct inode *new_dir, | |
1941 | struct dentry *new_dentry) | |
1942 | { | |
1da177e4 | 1943 | struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; |
2bf49690 | 1944 | struct common_audit_data ad; |
275bb41e | 1945 | u32 sid = current_sid(); |
1da177e4 LT |
1946 | u32 av; |
1947 | int old_is_dir, new_is_dir; | |
1948 | int rc; | |
1949 | ||
83da53c5 AG |
1950 | old_dsec = inode_security(old_dir); |
1951 | old_isec = backing_inode_security(old_dentry); | |
e36cb0b8 | 1952 | old_is_dir = d_is_dir(old_dentry); |
83da53c5 | 1953 | new_dsec = inode_security(new_dir); |
1da177e4 | 1954 | |
50c205f5 | 1955 | ad.type = LSM_AUDIT_DATA_DENTRY; |
1da177e4 | 1956 | |
a269434d | 1957 | ad.u.dentry = old_dentry; |
275bb41e | 1958 | rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, |
1da177e4 LT |
1959 | DIR__REMOVE_NAME | DIR__SEARCH, &ad); |
1960 | if (rc) | |
1961 | return rc; | |
275bb41e | 1962 | rc = avc_has_perm(sid, old_isec->sid, |
1da177e4 LT |
1963 | old_isec->sclass, FILE__RENAME, &ad); |
1964 | if (rc) | |
1965 | return rc; | |
1966 | if (old_is_dir && new_dir != old_dir) { | |
275bb41e | 1967 | rc = avc_has_perm(sid, old_isec->sid, |
1da177e4 LT |
1968 | old_isec->sclass, DIR__REPARENT, &ad); |
1969 | if (rc) | |
1970 | return rc; | |
1971 | } | |
1972 | ||
a269434d | 1973 | ad.u.dentry = new_dentry; |
1da177e4 | 1974 | av = DIR__ADD_NAME | DIR__SEARCH; |
2c616d4d | 1975 | if (d_is_positive(new_dentry)) |
1da177e4 | 1976 | av |= DIR__REMOVE_NAME; |
275bb41e | 1977 | rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); |
1da177e4 LT |
1978 | if (rc) |
1979 | return rc; | |
2c616d4d | 1980 | if (d_is_positive(new_dentry)) { |
83da53c5 | 1981 | new_isec = backing_inode_security(new_dentry); |
e36cb0b8 | 1982 | new_is_dir = d_is_dir(new_dentry); |
275bb41e | 1983 | rc = avc_has_perm(sid, new_isec->sid, |
1da177e4 LT |
1984 | new_isec->sclass, |
1985 | (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); | |
1986 | if (rc) | |
1987 | return rc; | |
1988 | } | |
1989 | ||
1990 | return 0; | |
1991 | } | |
1992 | ||
1993 | /* Check whether a task can perform a filesystem operation. */ | |
88e67f3b | 1994 | static int superblock_has_perm(const struct cred *cred, |
1da177e4 LT |
1995 | struct super_block *sb, |
1996 | u32 perms, | |
2bf49690 | 1997 | struct common_audit_data *ad) |
1da177e4 | 1998 | { |
1da177e4 | 1999 | struct superblock_security_struct *sbsec; |
88e67f3b | 2000 | u32 sid = cred_sid(cred); |
1da177e4 | 2001 | |
1da177e4 | 2002 | sbsec = sb->s_security; |
275bb41e | 2003 | return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); |
1da177e4 LT |
2004 | } |
2005 | ||
2006 | /* Convert a Linux mode and permission mask to an access vector. */ | |
2007 | static inline u32 file_mask_to_av(int mode, int mask) | |
2008 | { | |
2009 | u32 av = 0; | |
2010 | ||
dba19c60 | 2011 | if (!S_ISDIR(mode)) { |
1da177e4 LT |
2012 | if (mask & MAY_EXEC) |
2013 | av |= FILE__EXECUTE; | |
2014 | if (mask & MAY_READ) | |
2015 | av |= FILE__READ; | |
2016 | ||
2017 | if (mask & MAY_APPEND) | |
2018 | av |= FILE__APPEND; | |
2019 | else if (mask & MAY_WRITE) | |
2020 | av |= FILE__WRITE; | |
2021 | ||
2022 | } else { | |
2023 | if (mask & MAY_EXEC) | |
2024 | av |= DIR__SEARCH; | |
2025 | if (mask & MAY_WRITE) | |
2026 | av |= DIR__WRITE; | |
2027 | if (mask & MAY_READ) | |
2028 | av |= DIR__READ; | |
2029 | } | |
2030 | ||
2031 | return av; | |
2032 | } | |
2033 | ||
8b6a5a37 EP |
2034 | /* Convert a Linux file to an access vector. */ |
2035 | static inline u32 file_to_av(struct file *file) | |
2036 | { | |
2037 | u32 av = 0; | |
2038 | ||
2039 | if (file->f_mode & FMODE_READ) | |
2040 | av |= FILE__READ; | |
2041 | if (file->f_mode & FMODE_WRITE) { | |
2042 | if (file->f_flags & O_APPEND) | |
2043 | av |= FILE__APPEND; | |
2044 | else | |
2045 | av |= FILE__WRITE; | |
2046 | } | |
2047 | if (!av) { | |
2048 | /* | |
2049 | * Special file opened with flags 3 for ioctl-only use. | |
2050 | */ | |
2051 | av = FILE__IOCTL; | |
2052 | } | |
2053 | ||
2054 | return av; | |
2055 | } | |
2056 | ||
b0c636b9 | 2057 | /* |
8b6a5a37 | 2058 | * Convert a file to an access vector and include the correct open |
b0c636b9 EP |
2059 | * open permission. |
2060 | */ | |
8b6a5a37 | 2061 | static inline u32 open_file_to_av(struct file *file) |
b0c636b9 | 2062 | { |
8b6a5a37 | 2063 | u32 av = file_to_av(file); |
b0c636b9 | 2064 | |
49b7b8de EP |
2065 | if (selinux_policycap_openperm) |
2066 | av |= FILE__OPEN; | |
2067 | ||
b0c636b9 EP |
2068 | return av; |
2069 | } | |
2070 | ||
1da177e4 LT |
2071 | /* Hook functions begin here. */ |
2072 | ||
79af7307 SS |
2073 | static int selinux_binder_set_context_mgr(struct task_struct *mgr) |
2074 | { | |
2075 | u32 mysid = current_sid(); | |
2076 | u32 mgrsid = task_sid(mgr); | |
2077 | ||
2078 | return avc_has_perm(mysid, mgrsid, SECCLASS_BINDER, | |
2079 | BINDER__SET_CONTEXT_MGR, NULL); | |
2080 | } | |
2081 | ||
2082 | static int selinux_binder_transaction(struct task_struct *from, | |
2083 | struct task_struct *to) | |
2084 | { | |
2085 | u32 mysid = current_sid(); | |
2086 | u32 fromsid = task_sid(from); | |
2087 | u32 tosid = task_sid(to); | |
2088 | int rc; | |
2089 | ||
2090 | if (mysid != fromsid) { | |
2091 | rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER, | |
2092 | BINDER__IMPERSONATE, NULL); | |
2093 | if (rc) | |
2094 | return rc; | |
2095 | } | |
2096 | ||
2097 | return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__CALL, | |
2098 | NULL); | |
2099 | } | |
2100 | ||
2101 | static int selinux_binder_transfer_binder(struct task_struct *from, | |
2102 | struct task_struct *to) | |
2103 | { | |
2104 | u32 fromsid = task_sid(from); | |
2105 | u32 tosid = task_sid(to); | |
2106 | ||
2107 | return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER, | |
2108 | NULL); | |
2109 | } | |
2110 | ||
2111 | static int selinux_binder_transfer_file(struct task_struct *from, | |
2112 | struct task_struct *to, | |
2113 | struct file *file) | |
2114 | { | |
2115 | u32 sid = task_sid(to); | |
2116 | struct file_security_struct *fsec = file->f_security; | |
83da53c5 | 2117 | struct dentry *dentry = file->f_path.dentry; |
20cdef8d | 2118 | struct inode_security_struct *isec; |
79af7307 SS |
2119 | struct common_audit_data ad; |
2120 | int rc; | |
2121 | ||
2122 | ad.type = LSM_AUDIT_DATA_PATH; | |
2123 | ad.u.path = file->f_path; | |
2124 | ||
2125 | if (sid != fsec->sid) { | |
2126 | rc = avc_has_perm(sid, fsec->sid, | |
2127 | SECCLASS_FD, | |
2128 | FD__USE, | |
2129 | &ad); | |
2130 | if (rc) | |
2131 | return rc; | |
2132 | } | |
2133 | ||
83da53c5 | 2134 | if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) |
79af7307 SS |
2135 | return 0; |
2136 | ||
20cdef8d | 2137 | isec = backing_inode_security(dentry); |
79af7307 SS |
2138 | return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file), |
2139 | &ad); | |
2140 | } | |
2141 | ||
9e48858f | 2142 | static int selinux_ptrace_access_check(struct task_struct *child, |
5cd9c58f | 2143 | unsigned int mode) |
1da177e4 | 2144 | { |
be0554c9 SS |
2145 | u32 sid = current_sid(); |
2146 | u32 csid = task_sid(child); | |
2147 | ||
2148 | if (mode & PTRACE_MODE_READ) | |
275bb41e | 2149 | return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); |
006ebb40 | 2150 | |
be0554c9 | 2151 | return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL); |
5cd9c58f DH |
2152 | } |
2153 | ||
2154 | static int selinux_ptrace_traceme(struct task_struct *parent) | |
2155 | { | |
be0554c9 SS |
2156 | return avc_has_perm(task_sid(parent), current_sid(), SECCLASS_PROCESS, |
2157 | PROCESS__PTRACE, NULL); | |
1da177e4 LT |
2158 | } |
2159 | ||
2160 | static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, | |
828dfe1d | 2161 | kernel_cap_t *inheritable, kernel_cap_t *permitted) |
1da177e4 | 2162 | { |
be0554c9 SS |
2163 | return avc_has_perm(current_sid(), task_sid(target), SECCLASS_PROCESS, |
2164 | PROCESS__GETCAP, NULL); | |
1da177e4 LT |
2165 | } |
2166 | ||
d84f4f99 DH |
2167 | static int selinux_capset(struct cred *new, const struct cred *old, |
2168 | const kernel_cap_t *effective, | |
2169 | const kernel_cap_t *inheritable, | |
2170 | const kernel_cap_t *permitted) | |
1da177e4 | 2171 | { |
be0554c9 SS |
2172 | return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS, |
2173 | PROCESS__SETCAP, NULL); | |
1da177e4 LT |
2174 | } |
2175 | ||
5626d3e8 JM |
2176 | /* |
2177 | * (This comment used to live with the selinux_task_setuid hook, | |
2178 | * which was removed). | |
2179 | * | |
2180 | * Since setuid only affects the current process, and since the SELinux | |
2181 | * controls are not based on the Linux identity attributes, SELinux does not | |
2182 | * need to control this operation. However, SELinux does control the use of | |
2183 | * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. | |
2184 | */ | |
2185 | ||
6a9de491 EP |
2186 | static int selinux_capable(const struct cred *cred, struct user_namespace *ns, |
2187 | int cap, int audit) | |
1da177e4 | 2188 | { |
8e4ff6f2 | 2189 | return cred_has_capability(cred, cap, audit, ns == &init_user_ns); |
1da177e4 LT |
2190 | } |
2191 | ||
1da177e4 LT |
2192 | static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) |
2193 | { | |
88e67f3b | 2194 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2195 | int rc = 0; |
2196 | ||
2197 | if (!sb) | |
2198 | return 0; | |
2199 | ||
2200 | switch (cmds) { | |
828dfe1d EP |
2201 | case Q_SYNC: |
2202 | case Q_QUOTAON: | |
2203 | case Q_QUOTAOFF: | |
2204 | case Q_SETINFO: | |
2205 | case Q_SETQUOTA: | |
88e67f3b | 2206 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); |
828dfe1d EP |
2207 | break; |
2208 | case Q_GETFMT: | |
2209 | case Q_GETINFO: | |
2210 | case Q_GETQUOTA: | |
88e67f3b | 2211 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); |
828dfe1d EP |
2212 | break; |
2213 | default: | |
2214 | rc = 0; /* let the kernel handle invalid cmds */ | |
2215 | break; | |
1da177e4 LT |
2216 | } |
2217 | return rc; | |
2218 | } | |
2219 | ||
2220 | static int selinux_quota_on(struct dentry *dentry) | |
2221 | { | |
88e67f3b DH |
2222 | const struct cred *cred = current_cred(); |
2223 | ||
2875fa00 | 2224 | return dentry_has_perm(cred, dentry, FILE__QUOTAON); |
1da177e4 LT |
2225 | } |
2226 | ||
12b3052c | 2227 | static int selinux_syslog(int type) |
1da177e4 | 2228 | { |
1da177e4 | 2229 | switch (type) { |
d78ca3cd KC |
2230 | case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ |
2231 | case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ | |
be0554c9 SS |
2232 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, |
2233 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL); | |
d78ca3cd KC |
2234 | case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ |
2235 | case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ | |
2236 | /* Set level of messages printed to console */ | |
2237 | case SYSLOG_ACTION_CONSOLE_LEVEL: | |
be0554c9 SS |
2238 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, |
2239 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, | |
2240 | NULL); | |
1da177e4 | 2241 | } |
be0554c9 SS |
2242 | /* All other syslog types */ |
2243 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, | |
2244 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL); | |
1da177e4 LT |
2245 | } |
2246 | ||
2247 | /* | |
2248 | * Check that a process has enough memory to allocate a new virtual | |
2249 | * mapping. 0 means there is enough memory for the allocation to | |
2250 | * succeed and -ENOMEM implies there is not. | |
2251 | * | |
1da177e4 LT |
2252 | * Do not audit the selinux permission check, as this is applied to all |
2253 | * processes that allocate mappings. | |
2254 | */ | |
34b4e4aa | 2255 | static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
2256 | { |
2257 | int rc, cap_sys_admin = 0; | |
1da177e4 | 2258 | |
b1d9e6b0 | 2259 | rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN, |
8e4ff6f2 | 2260 | SECURITY_CAP_NOAUDIT, true); |
1da177e4 LT |
2261 | if (rc == 0) |
2262 | cap_sys_admin = 1; | |
2263 | ||
b1d9e6b0 | 2264 | return cap_sys_admin; |
1da177e4 LT |
2265 | } |
2266 | ||
2267 | /* binprm security operations */ | |
2268 | ||
be0554c9 | 2269 | static u32 ptrace_parent_sid(void) |
0c6181cb PM |
2270 | { |
2271 | u32 sid = 0; | |
2272 | struct task_struct *tracer; | |
2273 | ||
2274 | rcu_read_lock(); | |
be0554c9 | 2275 | tracer = ptrace_parent(current); |
0c6181cb PM |
2276 | if (tracer) |
2277 | sid = task_sid(tracer); | |
2278 | rcu_read_unlock(); | |
2279 | ||
2280 | return sid; | |
2281 | } | |
2282 | ||
7b0d0b40 SS |
2283 | static int check_nnp_nosuid(const struct linux_binprm *bprm, |
2284 | const struct task_security_struct *old_tsec, | |
2285 | const struct task_security_struct *new_tsec) | |
2286 | { | |
2287 | int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); | |
380cf5ba | 2288 | int nosuid = !mnt_may_suid(bprm->file->f_path.mnt); |
7b0d0b40 SS |
2289 | int rc; |
2290 | ||
2291 | if (!nnp && !nosuid) | |
2292 | return 0; /* neither NNP nor nosuid */ | |
2293 | ||
2294 | if (new_tsec->sid == old_tsec->sid) | |
2295 | return 0; /* No change in credentials */ | |
2296 | ||
2297 | /* | |
2298 | * The only transitions we permit under NNP or nosuid | |
2299 | * are transitions to bounded SIDs, i.e. SIDs that are | |
2300 | * guaranteed to only be allowed a subset of the permissions | |
2301 | * of the current SID. | |
2302 | */ | |
2303 | rc = security_bounded_transition(old_tsec->sid, new_tsec->sid); | |
2304 | if (rc) { | |
2305 | /* | |
2306 | * On failure, preserve the errno values for NNP vs nosuid. | |
2307 | * NNP: Operation not permitted for caller. | |
2308 | * nosuid: Permission denied to file. | |
2309 | */ | |
2310 | if (nnp) | |
2311 | return -EPERM; | |
2312 | else | |
2313 | return -EACCES; | |
2314 | } | |
2315 | return 0; | |
2316 | } | |
2317 | ||
a6f76f23 | 2318 | static int selinux_bprm_set_creds(struct linux_binprm *bprm) |
1da177e4 | 2319 | { |
a6f76f23 DH |
2320 | const struct task_security_struct *old_tsec; |
2321 | struct task_security_struct *new_tsec; | |
1da177e4 | 2322 | struct inode_security_struct *isec; |
2bf49690 | 2323 | struct common_audit_data ad; |
496ad9aa | 2324 | struct inode *inode = file_inode(bprm->file); |
1da177e4 LT |
2325 | int rc; |
2326 | ||
a6f76f23 DH |
2327 | /* SELinux context only depends on initial program or script and not |
2328 | * the script interpreter */ | |
2329 | if (bprm->cred_prepared) | |
1da177e4 LT |
2330 | return 0; |
2331 | ||
a6f76f23 DH |
2332 | old_tsec = current_security(); |
2333 | new_tsec = bprm->cred->security; | |
83da53c5 | 2334 | isec = inode_security(inode); |
1da177e4 LT |
2335 | |
2336 | /* Default to the current task SID. */ | |
a6f76f23 DH |
2337 | new_tsec->sid = old_tsec->sid; |
2338 | new_tsec->osid = old_tsec->sid; | |
1da177e4 | 2339 | |
28eba5bf | 2340 | /* Reset fs, key, and sock SIDs on execve. */ |
a6f76f23 DH |
2341 | new_tsec->create_sid = 0; |
2342 | new_tsec->keycreate_sid = 0; | |
2343 | new_tsec->sockcreate_sid = 0; | |
1da177e4 | 2344 | |
a6f76f23 DH |
2345 | if (old_tsec->exec_sid) { |
2346 | new_tsec->sid = old_tsec->exec_sid; | |
1da177e4 | 2347 | /* Reset exec SID on execve. */ |
a6f76f23 | 2348 | new_tsec->exec_sid = 0; |
259e5e6c | 2349 | |
7b0d0b40 SS |
2350 | /* Fail on NNP or nosuid if not an allowed transition. */ |
2351 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2352 | if (rc) | |
2353 | return rc; | |
1da177e4 LT |
2354 | } else { |
2355 | /* Check for a default transition on this program. */ | |
a6f76f23 | 2356 | rc = security_transition_sid(old_tsec->sid, isec->sid, |
652bb9b0 EP |
2357 | SECCLASS_PROCESS, NULL, |
2358 | &new_tsec->sid); | |
1da177e4 LT |
2359 | if (rc) |
2360 | return rc; | |
7b0d0b40 SS |
2361 | |
2362 | /* | |
2363 | * Fallback to old SID on NNP or nosuid if not an allowed | |
2364 | * transition. | |
2365 | */ | |
2366 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2367 | if (rc) | |
2368 | new_tsec->sid = old_tsec->sid; | |
1da177e4 LT |
2369 | } |
2370 | ||
43af5de7 VG |
2371 | ad.type = LSM_AUDIT_DATA_FILE; |
2372 | ad.u.file = bprm->file; | |
1da177e4 | 2373 | |
a6f76f23 DH |
2374 | if (new_tsec->sid == old_tsec->sid) { |
2375 | rc = avc_has_perm(old_tsec->sid, isec->sid, | |
1da177e4 LT |
2376 | SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); |
2377 | if (rc) | |
2378 | return rc; | |
2379 | } else { | |
2380 | /* Check permissions for the transition. */ | |
a6f76f23 | 2381 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, |
1da177e4 LT |
2382 | SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); |
2383 | if (rc) | |
2384 | return rc; | |
2385 | ||
a6f76f23 | 2386 | rc = avc_has_perm(new_tsec->sid, isec->sid, |
1da177e4 LT |
2387 | SECCLASS_FILE, FILE__ENTRYPOINT, &ad); |
2388 | if (rc) | |
2389 | return rc; | |
2390 | ||
a6f76f23 DH |
2391 | /* Check for shared state */ |
2392 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
2393 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, | |
2394 | SECCLASS_PROCESS, PROCESS__SHARE, | |
2395 | NULL); | |
2396 | if (rc) | |
2397 | return -EPERM; | |
2398 | } | |
2399 | ||
2400 | /* Make sure that anyone attempting to ptrace over a task that | |
2401 | * changes its SID has the appropriate permit */ | |
9227dd2a | 2402 | if (bprm->unsafe & LSM_UNSAFE_PTRACE) { |
be0554c9 | 2403 | u32 ptsid = ptrace_parent_sid(); |
a6f76f23 DH |
2404 | if (ptsid != 0) { |
2405 | rc = avc_has_perm(ptsid, new_tsec->sid, | |
2406 | SECCLASS_PROCESS, | |
2407 | PROCESS__PTRACE, NULL); | |
2408 | if (rc) | |
2409 | return -EPERM; | |
2410 | } | |
2411 | } | |
1da177e4 | 2412 | |
a6f76f23 DH |
2413 | /* Clear any possibly unsafe personality bits on exec: */ |
2414 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
1da177e4 LT |
2415 | } |
2416 | ||
1da177e4 LT |
2417 | return 0; |
2418 | } | |
2419 | ||
828dfe1d | 2420 | static int selinux_bprm_secureexec(struct linux_binprm *bprm) |
1da177e4 | 2421 | { |
5fb49870 | 2422 | const struct task_security_struct *tsec = current_security(); |
275bb41e | 2423 | u32 sid, osid; |
1da177e4 LT |
2424 | int atsecure = 0; |
2425 | ||
275bb41e DH |
2426 | sid = tsec->sid; |
2427 | osid = tsec->osid; | |
2428 | ||
2429 | if (osid != sid) { | |
1da177e4 LT |
2430 | /* Enable secure mode for SIDs transitions unless |
2431 | the noatsecure permission is granted between | |
2432 | the two SIDs, i.e. ahp returns 0. */ | |
275bb41e | 2433 | atsecure = avc_has_perm(osid, sid, |
a6f76f23 DH |
2434 | SECCLASS_PROCESS, |
2435 | PROCESS__NOATSECURE, NULL); | |
1da177e4 LT |
2436 | } |
2437 | ||
b1d9e6b0 | 2438 | return !!atsecure; |
1da177e4 LT |
2439 | } |
2440 | ||
c3c073f8 AV |
2441 | static int match_file(const void *p, struct file *file, unsigned fd) |
2442 | { | |
2443 | return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; | |
2444 | } | |
2445 | ||
1da177e4 | 2446 | /* Derived from fs/exec.c:flush_old_files. */ |
745ca247 DH |
2447 | static inline void flush_unauthorized_files(const struct cred *cred, |
2448 | struct files_struct *files) | |
1da177e4 | 2449 | { |
1da177e4 | 2450 | struct file *file, *devnull = NULL; |
b20c8122 | 2451 | struct tty_struct *tty; |
24ec839c | 2452 | int drop_tty = 0; |
c3c073f8 | 2453 | unsigned n; |
1da177e4 | 2454 | |
24ec839c | 2455 | tty = get_current_tty(); |
1da177e4 | 2456 | if (tty) { |
4a510969 | 2457 | spin_lock(&tty->files_lock); |
37dd0bd0 | 2458 | if (!list_empty(&tty->tty_files)) { |
d996b62a | 2459 | struct tty_file_private *file_priv; |
37dd0bd0 | 2460 | |
1da177e4 | 2461 | /* Revalidate access to controlling tty. |
13f8e981 DH |
2462 | Use file_path_has_perm on the tty path directly |
2463 | rather than using file_has_perm, as this particular | |
2464 | open file may belong to another process and we are | |
2465 | only interested in the inode-based check here. */ | |
d996b62a NP |
2466 | file_priv = list_first_entry(&tty->tty_files, |
2467 | struct tty_file_private, list); | |
2468 | file = file_priv->file; | |
13f8e981 | 2469 | if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE)) |
24ec839c | 2470 | drop_tty = 1; |
1da177e4 | 2471 | } |
4a510969 | 2472 | spin_unlock(&tty->files_lock); |
452a00d2 | 2473 | tty_kref_put(tty); |
1da177e4 | 2474 | } |
98a27ba4 EB |
2475 | /* Reset controlling tty. */ |
2476 | if (drop_tty) | |
2477 | no_tty(); | |
1da177e4 LT |
2478 | |
2479 | /* Revalidate access to inherited open files. */ | |
c3c073f8 AV |
2480 | n = iterate_fd(files, 0, match_file, cred); |
2481 | if (!n) /* none found? */ | |
2482 | return; | |
1da177e4 | 2483 | |
c3c073f8 | 2484 | devnull = dentry_open(&selinux_null, O_RDWR, cred); |
45525b26 AV |
2485 | if (IS_ERR(devnull)) |
2486 | devnull = NULL; | |
2487 | /* replace all the matching ones with this */ | |
2488 | do { | |
2489 | replace_fd(n - 1, devnull, 0); | |
2490 | } while ((n = iterate_fd(files, n, match_file, cred)) != 0); | |
2491 | if (devnull) | |
c3c073f8 | 2492 | fput(devnull); |
1da177e4 LT |
2493 | } |
2494 | ||
a6f76f23 DH |
2495 | /* |
2496 | * Prepare a process for imminent new credential changes due to exec | |
2497 | */ | |
2498 | static void selinux_bprm_committing_creds(struct linux_binprm *bprm) | |
1da177e4 | 2499 | { |
a6f76f23 DH |
2500 | struct task_security_struct *new_tsec; |
2501 | struct rlimit *rlim, *initrlim; | |
2502 | int rc, i; | |
d84f4f99 | 2503 | |
a6f76f23 DH |
2504 | new_tsec = bprm->cred->security; |
2505 | if (new_tsec->sid == new_tsec->osid) | |
2506 | return; | |
1da177e4 | 2507 | |
a6f76f23 DH |
2508 | /* Close files for which the new task SID is not authorized. */ |
2509 | flush_unauthorized_files(bprm->cred, current->files); | |
0356357c | 2510 | |
a6f76f23 DH |
2511 | /* Always clear parent death signal on SID transitions. */ |
2512 | current->pdeath_signal = 0; | |
0356357c | 2513 | |
a6f76f23 DH |
2514 | /* Check whether the new SID can inherit resource limits from the old |
2515 | * SID. If not, reset all soft limits to the lower of the current | |
2516 | * task's hard limit and the init task's soft limit. | |
2517 | * | |
2518 | * Note that the setting of hard limits (even to lower them) can be | |
2519 | * controlled by the setrlimit check. The inclusion of the init task's | |
2520 | * soft limit into the computation is to avoid resetting soft limits | |
2521 | * higher than the default soft limit for cases where the default is | |
2522 | * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. | |
2523 | */ | |
2524 | rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, | |
2525 | PROCESS__RLIMITINH, NULL); | |
2526 | if (rc) { | |
eb2d55a3 ON |
2527 | /* protect against do_prlimit() */ |
2528 | task_lock(current); | |
a6f76f23 DH |
2529 | for (i = 0; i < RLIM_NLIMITS; i++) { |
2530 | rlim = current->signal->rlim + i; | |
2531 | initrlim = init_task.signal->rlim + i; | |
2532 | rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); | |
1da177e4 | 2533 | } |
eb2d55a3 | 2534 | task_unlock(current); |
baa73d9e NP |
2535 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) |
2536 | update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); | |
1da177e4 LT |
2537 | } |
2538 | } | |
2539 | ||
2540 | /* | |
a6f76f23 DH |
2541 | * Clean up the process immediately after the installation of new credentials |
2542 | * due to exec | |
1da177e4 | 2543 | */ |
a6f76f23 | 2544 | static void selinux_bprm_committed_creds(struct linux_binprm *bprm) |
1da177e4 | 2545 | { |
a6f76f23 | 2546 | const struct task_security_struct *tsec = current_security(); |
1da177e4 | 2547 | struct itimerval itimer; |
a6f76f23 | 2548 | u32 osid, sid; |
1da177e4 LT |
2549 | int rc, i; |
2550 | ||
a6f76f23 DH |
2551 | osid = tsec->osid; |
2552 | sid = tsec->sid; | |
2553 | ||
2554 | if (sid == osid) | |
1da177e4 LT |
2555 | return; |
2556 | ||
a6f76f23 DH |
2557 | /* Check whether the new SID can inherit signal state from the old SID. |
2558 | * If not, clear itimers to avoid subsequent signal generation and | |
2559 | * flush and unblock signals. | |
2560 | * | |
2561 | * This must occur _after_ the task SID has been updated so that any | |
2562 | * kill done after the flush will be checked against the new SID. | |
2563 | */ | |
2564 | rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); | |
1da177e4 | 2565 | if (rc) { |
baa73d9e NP |
2566 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) { |
2567 | memset(&itimer, 0, sizeof itimer); | |
2568 | for (i = 0; i < 3; i++) | |
2569 | do_setitimer(i, &itimer, NULL); | |
2570 | } | |
1da177e4 | 2571 | spin_lock_irq(¤t->sighand->siglock); |
9e7c8f8c ON |
2572 | if (!fatal_signal_pending(current)) { |
2573 | flush_sigqueue(¤t->pending); | |
2574 | flush_sigqueue(¤t->signal->shared_pending); | |
3bcac026 DH |
2575 | flush_signal_handlers(current, 1); |
2576 | sigemptyset(¤t->blocked); | |
9e7c8f8c | 2577 | recalc_sigpending(); |
3bcac026 | 2578 | } |
1da177e4 LT |
2579 | spin_unlock_irq(¤t->sighand->siglock); |
2580 | } | |
2581 | ||
a6f76f23 DH |
2582 | /* Wake up the parent if it is waiting so that it can recheck |
2583 | * wait permission to the new task SID. */ | |
ecd6de3c | 2584 | read_lock(&tasklist_lock); |
0b7570e7 | 2585 | __wake_up_parent(current, current->real_parent); |
ecd6de3c | 2586 | read_unlock(&tasklist_lock); |
1da177e4 LT |
2587 | } |
2588 | ||
2589 | /* superblock security operations */ | |
2590 | ||
2591 | static int selinux_sb_alloc_security(struct super_block *sb) | |
2592 | { | |
2593 | return superblock_alloc_security(sb); | |
2594 | } | |
2595 | ||
2596 | static void selinux_sb_free_security(struct super_block *sb) | |
2597 | { | |
2598 | superblock_free_security(sb); | |
2599 | } | |
2600 | ||
2601 | static inline int match_prefix(char *prefix, int plen, char *option, int olen) | |
2602 | { | |
2603 | if (plen > olen) | |
2604 | return 0; | |
2605 | ||
2606 | return !memcmp(prefix, option, plen); | |
2607 | } | |
2608 | ||
2609 | static inline int selinux_option(char *option, int len) | |
2610 | { | |
832cbd9a EP |
2611 | return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || |
2612 | match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || | |
2613 | match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || | |
11689d47 DQ |
2614 | match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || |
2615 | match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); | |
1da177e4 LT |
2616 | } |
2617 | ||
2618 | static inline void take_option(char **to, char *from, int *first, int len) | |
2619 | { | |
2620 | if (!*first) { | |
2621 | **to = ','; | |
2622 | *to += 1; | |
3528a953 | 2623 | } else |
1da177e4 LT |
2624 | *first = 0; |
2625 | memcpy(*to, from, len); | |
2626 | *to += len; | |
2627 | } | |
2628 | ||
828dfe1d EP |
2629 | static inline void take_selinux_option(char **to, char *from, int *first, |
2630 | int len) | |
3528a953 CO |
2631 | { |
2632 | int current_size = 0; | |
2633 | ||
2634 | if (!*first) { | |
2635 | **to = '|'; | |
2636 | *to += 1; | |
828dfe1d | 2637 | } else |
3528a953 CO |
2638 | *first = 0; |
2639 | ||
2640 | while (current_size < len) { | |
2641 | if (*from != '"') { | |
2642 | **to = *from; | |
2643 | *to += 1; | |
2644 | } | |
2645 | from += 1; | |
2646 | current_size += 1; | |
2647 | } | |
2648 | } | |
2649 | ||
e0007529 | 2650 | static int selinux_sb_copy_data(char *orig, char *copy) |
1da177e4 LT |
2651 | { |
2652 | int fnosec, fsec, rc = 0; | |
2653 | char *in_save, *in_curr, *in_end; | |
2654 | char *sec_curr, *nosec_save, *nosec; | |
3528a953 | 2655 | int open_quote = 0; |
1da177e4 LT |
2656 | |
2657 | in_curr = orig; | |
2658 | sec_curr = copy; | |
2659 | ||
1da177e4 LT |
2660 | nosec = (char *)get_zeroed_page(GFP_KERNEL); |
2661 | if (!nosec) { | |
2662 | rc = -ENOMEM; | |
2663 | goto out; | |
2664 | } | |
2665 | ||
2666 | nosec_save = nosec; | |
2667 | fnosec = fsec = 1; | |
2668 | in_save = in_end = orig; | |
2669 | ||
2670 | do { | |
3528a953 CO |
2671 | if (*in_end == '"') |
2672 | open_quote = !open_quote; | |
2673 | if ((*in_end == ',' && open_quote == 0) || | |
2674 | *in_end == '\0') { | |
1da177e4 LT |
2675 | int len = in_end - in_curr; |
2676 | ||
2677 | if (selinux_option(in_curr, len)) | |
3528a953 | 2678 | take_selinux_option(&sec_curr, in_curr, &fsec, len); |
1da177e4 LT |
2679 | else |
2680 | take_option(&nosec, in_curr, &fnosec, len); | |
2681 | ||
2682 | in_curr = in_end + 1; | |
2683 | } | |
2684 | } while (*in_end++); | |
2685 | ||
6931dfc9 | 2686 | strcpy(in_save, nosec_save); |
da3caa20 | 2687 | free_page((unsigned long)nosec_save); |
1da177e4 LT |
2688 | out: |
2689 | return rc; | |
2690 | } | |
2691 | ||
026eb167 EP |
2692 | static int selinux_sb_remount(struct super_block *sb, void *data) |
2693 | { | |
2694 | int rc, i, *flags; | |
2695 | struct security_mnt_opts opts; | |
2696 | char *secdata, **mount_options; | |
2697 | struct superblock_security_struct *sbsec = sb->s_security; | |
2698 | ||
2699 | if (!(sbsec->flags & SE_SBINITIALIZED)) | |
2700 | return 0; | |
2701 | ||
2702 | if (!data) | |
2703 | return 0; | |
2704 | ||
2705 | if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) | |
2706 | return 0; | |
2707 | ||
2708 | security_init_mnt_opts(&opts); | |
2709 | secdata = alloc_secdata(); | |
2710 | if (!secdata) | |
2711 | return -ENOMEM; | |
2712 | rc = selinux_sb_copy_data(data, secdata); | |
2713 | if (rc) | |
2714 | goto out_free_secdata; | |
2715 | ||
2716 | rc = selinux_parse_opts_str(secdata, &opts); | |
2717 | if (rc) | |
2718 | goto out_free_secdata; | |
2719 | ||
2720 | mount_options = opts.mnt_opts; | |
2721 | flags = opts.mnt_opts_flags; | |
2722 | ||
2723 | for (i = 0; i < opts.num_mnt_opts; i++) { | |
2724 | u32 sid; | |
026eb167 | 2725 | |
12f348b9 | 2726 | if (flags[i] == SBLABEL_MNT) |
026eb167 | 2727 | continue; |
44be2f65 | 2728 | rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL); |
026eb167 | 2729 | if (rc) { |
44be2f65 | 2730 | printk(KERN_WARNING "SELinux: security_context_str_to_sid" |
29b1deb2 LT |
2731 | "(%s) failed for (dev %s, type %s) errno=%d\n", |
2732 | mount_options[i], sb->s_id, sb->s_type->name, rc); | |
026eb167 EP |
2733 | goto out_free_opts; |
2734 | } | |
2735 | rc = -EINVAL; | |
2736 | switch (flags[i]) { | |
2737 | case FSCONTEXT_MNT: | |
2738 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) | |
2739 | goto out_bad_option; | |
2740 | break; | |
2741 | case CONTEXT_MNT: | |
2742 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) | |
2743 | goto out_bad_option; | |
2744 | break; | |
2745 | case ROOTCONTEXT_MNT: { | |
2746 | struct inode_security_struct *root_isec; | |
83da53c5 | 2747 | root_isec = backing_inode_security(sb->s_root); |
026eb167 EP |
2748 | |
2749 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) | |
2750 | goto out_bad_option; | |
2751 | break; | |
2752 | } | |
2753 | case DEFCONTEXT_MNT: | |
2754 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) | |
2755 | goto out_bad_option; | |
2756 | break; | |
2757 | default: | |
2758 | goto out_free_opts; | |
2759 | } | |
2760 | } | |
2761 | ||
2762 | rc = 0; | |
2763 | out_free_opts: | |
2764 | security_free_mnt_opts(&opts); | |
2765 | out_free_secdata: | |
2766 | free_secdata(secdata); | |
2767 | return rc; | |
2768 | out_bad_option: | |
2769 | printk(KERN_WARNING "SELinux: unable to change security options " | |
29b1deb2 LT |
2770 | "during remount (dev %s, type=%s)\n", sb->s_id, |
2771 | sb->s_type->name); | |
026eb167 EP |
2772 | goto out_free_opts; |
2773 | } | |
2774 | ||
12204e24 | 2775 | static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) |
1da177e4 | 2776 | { |
88e67f3b | 2777 | const struct cred *cred = current_cred(); |
2bf49690 | 2778 | struct common_audit_data ad; |
1da177e4 LT |
2779 | int rc; |
2780 | ||
2781 | rc = superblock_doinit(sb, data); | |
2782 | if (rc) | |
2783 | return rc; | |
2784 | ||
74192246 JM |
2785 | /* Allow all mounts performed by the kernel */ |
2786 | if (flags & MS_KERNMOUNT) | |
2787 | return 0; | |
2788 | ||
50c205f5 | 2789 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2790 | ad.u.dentry = sb->s_root; |
88e67f3b | 2791 | return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); |
1da177e4 LT |
2792 | } |
2793 | ||
726c3342 | 2794 | static int selinux_sb_statfs(struct dentry *dentry) |
1da177e4 | 2795 | { |
88e67f3b | 2796 | const struct cred *cred = current_cred(); |
2bf49690 | 2797 | struct common_audit_data ad; |
1da177e4 | 2798 | |
50c205f5 | 2799 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2800 | ad.u.dentry = dentry->d_sb->s_root; |
88e67f3b | 2801 | return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); |
1da177e4 LT |
2802 | } |
2803 | ||
808d4e3c | 2804 | static int selinux_mount(const char *dev_name, |
8a04c43b | 2805 | const struct path *path, |
808d4e3c | 2806 | const char *type, |
828dfe1d EP |
2807 | unsigned long flags, |
2808 | void *data) | |
1da177e4 | 2809 | { |
88e67f3b | 2810 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2811 | |
2812 | if (flags & MS_REMOUNT) | |
d8c9584e | 2813 | return superblock_has_perm(cred, path->dentry->d_sb, |
828dfe1d | 2814 | FILESYSTEM__REMOUNT, NULL); |
1da177e4 | 2815 | else |
2875fa00 | 2816 | return path_has_perm(cred, path, FILE__MOUNTON); |
1da177e4 LT |
2817 | } |
2818 | ||
2819 | static int selinux_umount(struct vfsmount *mnt, int flags) | |
2820 | { | |
88e67f3b | 2821 | const struct cred *cred = current_cred(); |
1da177e4 | 2822 | |
88e67f3b | 2823 | return superblock_has_perm(cred, mnt->mnt_sb, |
828dfe1d | 2824 | FILESYSTEM__UNMOUNT, NULL); |
1da177e4 LT |
2825 | } |
2826 | ||
2827 | /* inode security operations */ | |
2828 | ||
2829 | static int selinux_inode_alloc_security(struct inode *inode) | |
2830 | { | |
2831 | return inode_alloc_security(inode); | |
2832 | } | |
2833 | ||
2834 | static void selinux_inode_free_security(struct inode *inode) | |
2835 | { | |
2836 | inode_free_security(inode); | |
2837 | } | |
2838 | ||
d47be3df | 2839 | static int selinux_dentry_init_security(struct dentry *dentry, int mode, |
4f3ccd76 | 2840 | const struct qstr *name, void **ctx, |
d47be3df DQ |
2841 | u32 *ctxlen) |
2842 | { | |
d47be3df DQ |
2843 | u32 newsid; |
2844 | int rc; | |
2845 | ||
c957f6df VG |
2846 | rc = selinux_determine_inode_label(current_security(), |
2847 | d_inode(dentry->d_parent), name, | |
c3c188b2 DH |
2848 | inode_mode_to_security_class(mode), |
2849 | &newsid); | |
2850 | if (rc) | |
2851 | return rc; | |
d47be3df DQ |
2852 | |
2853 | return security_sid_to_context(newsid, (char **)ctx, ctxlen); | |
2854 | } | |
2855 | ||
a518b0a5 VG |
2856 | static int selinux_dentry_create_files_as(struct dentry *dentry, int mode, |
2857 | struct qstr *name, | |
2858 | const struct cred *old, | |
2859 | struct cred *new) | |
2860 | { | |
2861 | u32 newsid; | |
2862 | int rc; | |
2863 | struct task_security_struct *tsec; | |
2864 | ||
2865 | rc = selinux_determine_inode_label(old->security, | |
2866 | d_inode(dentry->d_parent), name, | |
2867 | inode_mode_to_security_class(mode), | |
2868 | &newsid); | |
2869 | if (rc) | |
2870 | return rc; | |
2871 | ||
2872 | tsec = new->security; | |
2873 | tsec->create_sid = newsid; | |
2874 | return 0; | |
2875 | } | |
2876 | ||
5e41ff9e | 2877 | static int selinux_inode_init_security(struct inode *inode, struct inode *dir, |
9548906b TH |
2878 | const struct qstr *qstr, |
2879 | const char **name, | |
2a7dba39 | 2880 | void **value, size_t *len) |
5e41ff9e | 2881 | { |
5fb49870 | 2882 | const struct task_security_struct *tsec = current_security(); |
5e41ff9e | 2883 | struct superblock_security_struct *sbsec; |
275bb41e | 2884 | u32 sid, newsid, clen; |
5e41ff9e | 2885 | int rc; |
9548906b | 2886 | char *context; |
5e41ff9e | 2887 | |
5e41ff9e | 2888 | sbsec = dir->i_sb->s_security; |
5e41ff9e | 2889 | |
275bb41e DH |
2890 | sid = tsec->sid; |
2891 | newsid = tsec->create_sid; | |
2892 | ||
c957f6df | 2893 | rc = selinux_determine_inode_label(current_security(), |
c3c188b2 DH |
2894 | dir, qstr, |
2895 | inode_mode_to_security_class(inode->i_mode), | |
2896 | &newsid); | |
2897 | if (rc) | |
2898 | return rc; | |
5e41ff9e | 2899 | |
296fddf7 | 2900 | /* Possibly defer initialization to selinux_complete_init. */ |
0d90a7ec | 2901 | if (sbsec->flags & SE_SBINITIALIZED) { |
296fddf7 EP |
2902 | struct inode_security_struct *isec = inode->i_security; |
2903 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
2904 | isec->sid = newsid; | |
6f3be9f5 | 2905 | isec->initialized = LABEL_INITIALIZED; |
296fddf7 | 2906 | } |
5e41ff9e | 2907 | |
12f348b9 | 2908 | if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT)) |
25a74f3b SS |
2909 | return -EOPNOTSUPP; |
2910 | ||
9548906b TH |
2911 | if (name) |
2912 | *name = XATTR_SELINUX_SUFFIX; | |
5e41ff9e | 2913 | |
570bc1c2 | 2914 | if (value && len) { |
12b29f34 | 2915 | rc = security_sid_to_context_force(newsid, &context, &clen); |
9548906b | 2916 | if (rc) |
570bc1c2 | 2917 | return rc; |
570bc1c2 SS |
2918 | *value = context; |
2919 | *len = clen; | |
5e41ff9e | 2920 | } |
5e41ff9e | 2921 | |
5e41ff9e SS |
2922 | return 0; |
2923 | } | |
2924 | ||
4acdaf27 | 2925 | static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
2926 | { |
2927 | return may_create(dir, dentry, SECCLASS_FILE); | |
2928 | } | |
2929 | ||
1da177e4 LT |
2930 | static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) |
2931 | { | |
1da177e4 LT |
2932 | return may_link(dir, old_dentry, MAY_LINK); |
2933 | } | |
2934 | ||
1da177e4 LT |
2935 | static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) |
2936 | { | |
1da177e4 LT |
2937 | return may_link(dir, dentry, MAY_UNLINK); |
2938 | } | |
2939 | ||
2940 | static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) | |
2941 | { | |
2942 | return may_create(dir, dentry, SECCLASS_LNK_FILE); | |
2943 | } | |
2944 | ||
18bb1db3 | 2945 | static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) |
1da177e4 LT |
2946 | { |
2947 | return may_create(dir, dentry, SECCLASS_DIR); | |
2948 | } | |
2949 | ||
1da177e4 LT |
2950 | static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) |
2951 | { | |
2952 | return may_link(dir, dentry, MAY_RMDIR); | |
2953 | } | |
2954 | ||
1a67aafb | 2955 | static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 | 2956 | { |
1da177e4 LT |
2957 | return may_create(dir, dentry, inode_mode_to_security_class(mode)); |
2958 | } | |
2959 | ||
1da177e4 | 2960 | static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, |
828dfe1d | 2961 | struct inode *new_inode, struct dentry *new_dentry) |
1da177e4 LT |
2962 | { |
2963 | return may_rename(old_inode, old_dentry, new_inode, new_dentry); | |
2964 | } | |
2965 | ||
1da177e4 LT |
2966 | static int selinux_inode_readlink(struct dentry *dentry) |
2967 | { | |
88e67f3b DH |
2968 | const struct cred *cred = current_cred(); |
2969 | ||
2875fa00 | 2970 | return dentry_has_perm(cred, dentry, FILE__READ); |
1da177e4 LT |
2971 | } |
2972 | ||
bda0be7a N |
2973 | static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, |
2974 | bool rcu) | |
1da177e4 | 2975 | { |
88e67f3b | 2976 | const struct cred *cred = current_cred(); |
bda0be7a N |
2977 | struct common_audit_data ad; |
2978 | struct inode_security_struct *isec; | |
2979 | u32 sid; | |
1da177e4 | 2980 | |
bda0be7a N |
2981 | validate_creds(cred); |
2982 | ||
2983 | ad.type = LSM_AUDIT_DATA_DENTRY; | |
2984 | ad.u.dentry = dentry; | |
2985 | sid = cred_sid(cred); | |
5d226df4 AG |
2986 | isec = inode_security_rcu(inode, rcu); |
2987 | if (IS_ERR(isec)) | |
2988 | return PTR_ERR(isec); | |
bda0be7a N |
2989 | |
2990 | return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad, | |
2991 | rcu ? MAY_NOT_BLOCK : 0); | |
1da177e4 LT |
2992 | } |
2993 | ||
d4cf970d EP |
2994 | static noinline int audit_inode_permission(struct inode *inode, |
2995 | u32 perms, u32 audited, u32 denied, | |
626b9740 | 2996 | int result, |
d4cf970d | 2997 | unsigned flags) |
1da177e4 | 2998 | { |
b782e0a6 | 2999 | struct common_audit_data ad; |
d4cf970d EP |
3000 | struct inode_security_struct *isec = inode->i_security; |
3001 | int rc; | |
3002 | ||
50c205f5 | 3003 | ad.type = LSM_AUDIT_DATA_INODE; |
d4cf970d EP |
3004 | ad.u.inode = inode; |
3005 | ||
3006 | rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms, | |
626b9740 | 3007 | audited, denied, result, &ad, flags); |
d4cf970d EP |
3008 | if (rc) |
3009 | return rc; | |
3010 | return 0; | |
3011 | } | |
3012 | ||
e74f71eb | 3013 | static int selinux_inode_permission(struct inode *inode, int mask) |
1da177e4 | 3014 | { |
88e67f3b | 3015 | const struct cred *cred = current_cred(); |
b782e0a6 EP |
3016 | u32 perms; |
3017 | bool from_access; | |
cf1dd1da | 3018 | unsigned flags = mask & MAY_NOT_BLOCK; |
2e334057 EP |
3019 | struct inode_security_struct *isec; |
3020 | u32 sid; | |
3021 | struct av_decision avd; | |
3022 | int rc, rc2; | |
3023 | u32 audited, denied; | |
1da177e4 | 3024 | |
b782e0a6 | 3025 | from_access = mask & MAY_ACCESS; |
d09ca739 EP |
3026 | mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
3027 | ||
b782e0a6 EP |
3028 | /* No permission to check. Existence test. */ |
3029 | if (!mask) | |
1da177e4 | 3030 | return 0; |
1da177e4 | 3031 | |
2e334057 | 3032 | validate_creds(cred); |
b782e0a6 | 3033 | |
2e334057 EP |
3034 | if (unlikely(IS_PRIVATE(inode))) |
3035 | return 0; | |
b782e0a6 EP |
3036 | |
3037 | perms = file_mask_to_av(inode->i_mode, mask); | |
3038 | ||
2e334057 | 3039 | sid = cred_sid(cred); |
5d226df4 AG |
3040 | isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK); |
3041 | if (IS_ERR(isec)) | |
3042 | return PTR_ERR(isec); | |
2e334057 EP |
3043 | |
3044 | rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd); | |
3045 | audited = avc_audit_required(perms, &avd, rc, | |
3046 | from_access ? FILE__AUDIT_ACCESS : 0, | |
3047 | &denied); | |
3048 | if (likely(!audited)) | |
3049 | return rc; | |
3050 | ||
626b9740 | 3051 | rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags); |
2e334057 EP |
3052 | if (rc2) |
3053 | return rc2; | |
3054 | return rc; | |
1da177e4 LT |
3055 | } |
3056 | ||
3057 | static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
3058 | { | |
88e67f3b | 3059 | const struct cred *cred = current_cred(); |
bc6a6008 | 3060 | unsigned int ia_valid = iattr->ia_valid; |
95dbf739 | 3061 | __u32 av = FILE__WRITE; |
1da177e4 | 3062 | |
bc6a6008 AW |
3063 | /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ |
3064 | if (ia_valid & ATTR_FORCE) { | |
3065 | ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | | |
3066 | ATTR_FORCE); | |
3067 | if (!ia_valid) | |
3068 | return 0; | |
3069 | } | |
1da177e4 | 3070 | |
bc6a6008 AW |
3071 | if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | |
3072 | ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) | |
2875fa00 | 3073 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
1da177e4 | 3074 | |
44d37ad3 JVS |
3075 | if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE) |
3076 | && !(ia_valid & ATTR_FILE)) | |
95dbf739 EP |
3077 | av |= FILE__OPEN; |
3078 | ||
3079 | return dentry_has_perm(cred, dentry, av); | |
1da177e4 LT |
3080 | } |
3081 | ||
3f7036a0 | 3082 | static int selinux_inode_getattr(const struct path *path) |
1da177e4 | 3083 | { |
3f7036a0 | 3084 | return path_has_perm(current_cred(), path, FILE__GETATTR); |
1da177e4 LT |
3085 | } |
3086 | ||
8f0cfa52 | 3087 | static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) |
b5376771 | 3088 | { |
88e67f3b DH |
3089 | const struct cred *cred = current_cred(); |
3090 | ||
b5376771 SH |
3091 | if (!strncmp(name, XATTR_SECURITY_PREFIX, |
3092 | sizeof XATTR_SECURITY_PREFIX - 1)) { | |
3093 | if (!strcmp(name, XATTR_NAME_CAPS)) { | |
3094 | if (!capable(CAP_SETFCAP)) | |
3095 | return -EPERM; | |
3096 | } else if (!capable(CAP_SYS_ADMIN)) { | |
3097 | /* A different attribute in the security namespace. | |
3098 | Restrict to administrator. */ | |
3099 | return -EPERM; | |
3100 | } | |
3101 | } | |
3102 | ||
3103 | /* Not an attribute we recognize, so just check the | |
3104 | ordinary setattr permission. */ | |
2875fa00 | 3105 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
b5376771 SH |
3106 | } |
3107 | ||
8f0cfa52 DH |
3108 | static int selinux_inode_setxattr(struct dentry *dentry, const char *name, |
3109 | const void *value, size_t size, int flags) | |
1da177e4 | 3110 | { |
c6f493d6 | 3111 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3112 | struct inode_security_struct *isec; |
1da177e4 | 3113 | struct superblock_security_struct *sbsec; |
2bf49690 | 3114 | struct common_audit_data ad; |
275bb41e | 3115 | u32 newsid, sid = current_sid(); |
1da177e4 LT |
3116 | int rc = 0; |
3117 | ||
b5376771 SH |
3118 | if (strcmp(name, XATTR_NAME_SELINUX)) |
3119 | return selinux_inode_setotherxattr(dentry, name); | |
1da177e4 LT |
3120 | |
3121 | sbsec = inode->i_sb->s_security; | |
12f348b9 | 3122 | if (!(sbsec->flags & SBLABEL_MNT)) |
1da177e4 LT |
3123 | return -EOPNOTSUPP; |
3124 | ||
2e149670 | 3125 | if (!inode_owner_or_capable(inode)) |
1da177e4 LT |
3126 | return -EPERM; |
3127 | ||
50c205f5 | 3128 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 3129 | ad.u.dentry = dentry; |
1da177e4 | 3130 | |
20cdef8d | 3131 | isec = backing_inode_security(dentry); |
275bb41e | 3132 | rc = avc_has_perm(sid, isec->sid, isec->sclass, |
1da177e4 LT |
3133 | FILE__RELABELFROM, &ad); |
3134 | if (rc) | |
3135 | return rc; | |
3136 | ||
52a4c640 | 3137 | rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL); |
12b29f34 | 3138 | if (rc == -EINVAL) { |
d6ea83ec EP |
3139 | if (!capable(CAP_MAC_ADMIN)) { |
3140 | struct audit_buffer *ab; | |
3141 | size_t audit_size; | |
3142 | const char *str; | |
3143 | ||
3144 | /* We strip a nul only if it is at the end, otherwise the | |
3145 | * context contains a nul and we should audit that */ | |
e3fea3f7 AV |
3146 | if (value) { |
3147 | str = value; | |
3148 | if (str[size - 1] == '\0') | |
3149 | audit_size = size - 1; | |
3150 | else | |
3151 | audit_size = size; | |
3152 | } else { | |
3153 | str = ""; | |
3154 | audit_size = 0; | |
3155 | } | |
d6ea83ec EP |
3156 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR); |
3157 | audit_log_format(ab, "op=setxattr invalid_context="); | |
3158 | audit_log_n_untrustedstring(ab, value, audit_size); | |
3159 | audit_log_end(ab); | |
3160 | ||
12b29f34 | 3161 | return rc; |
d6ea83ec | 3162 | } |
12b29f34 SS |
3163 | rc = security_context_to_sid_force(value, size, &newsid); |
3164 | } | |
1da177e4 LT |
3165 | if (rc) |
3166 | return rc; | |
3167 | ||
275bb41e | 3168 | rc = avc_has_perm(sid, newsid, isec->sclass, |
1da177e4 LT |
3169 | FILE__RELABELTO, &ad); |
3170 | if (rc) | |
3171 | return rc; | |
3172 | ||
275bb41e | 3173 | rc = security_validate_transition(isec->sid, newsid, sid, |
828dfe1d | 3174 | isec->sclass); |
1da177e4 LT |
3175 | if (rc) |
3176 | return rc; | |
3177 | ||
3178 | return avc_has_perm(newsid, | |
3179 | sbsec->sid, | |
3180 | SECCLASS_FILESYSTEM, | |
3181 | FILESYSTEM__ASSOCIATE, | |
3182 | &ad); | |
3183 | } | |
3184 | ||
8f0cfa52 | 3185 | static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, |
f5269710 | 3186 | const void *value, size_t size, |
8f0cfa52 | 3187 | int flags) |
1da177e4 | 3188 | { |
c6f493d6 | 3189 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3190 | struct inode_security_struct *isec; |
1da177e4 LT |
3191 | u32 newsid; |
3192 | int rc; | |
3193 | ||
3194 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
3195 | /* Not an attribute we recognize, so nothing to do. */ | |
3196 | return; | |
3197 | } | |
3198 | ||
12b29f34 | 3199 | rc = security_context_to_sid_force(value, size, &newsid); |
1da177e4 | 3200 | if (rc) { |
12b29f34 SS |
3201 | printk(KERN_ERR "SELinux: unable to map context to SID" |
3202 | "for (%s, %lu), rc=%d\n", | |
3203 | inode->i_sb->s_id, inode->i_ino, -rc); | |
1da177e4 LT |
3204 | return; |
3205 | } | |
3206 | ||
20cdef8d | 3207 | isec = backing_inode_security(dentry); |
9287aed2 | 3208 | spin_lock(&isec->lock); |
aa9c2669 | 3209 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3210 | isec->sid = newsid; |
6f3be9f5 | 3211 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3212 | spin_unlock(&isec->lock); |
aa9c2669 | 3213 | |
1da177e4 LT |
3214 | return; |
3215 | } | |
3216 | ||
8f0cfa52 | 3217 | static int selinux_inode_getxattr(struct dentry *dentry, const char *name) |
1da177e4 | 3218 | { |
88e67f3b DH |
3219 | const struct cred *cred = current_cred(); |
3220 | ||
2875fa00 | 3221 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3222 | } |
3223 | ||
828dfe1d | 3224 | static int selinux_inode_listxattr(struct dentry *dentry) |
1da177e4 | 3225 | { |
88e67f3b DH |
3226 | const struct cred *cred = current_cred(); |
3227 | ||
2875fa00 | 3228 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3229 | } |
3230 | ||
8f0cfa52 | 3231 | static int selinux_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 3232 | { |
b5376771 SH |
3233 | if (strcmp(name, XATTR_NAME_SELINUX)) |
3234 | return selinux_inode_setotherxattr(dentry, name); | |
1da177e4 LT |
3235 | |
3236 | /* No one is allowed to remove a SELinux security label. | |
3237 | You can change the label, but all data must be labeled. */ | |
3238 | return -EACCES; | |
3239 | } | |
3240 | ||
d381d8a9 | 3241 | /* |
abc69bb6 | 3242 | * Copy the inode security context value to the user. |
d381d8a9 JM |
3243 | * |
3244 | * Permission check is handled by selinux_inode_getxattr hook. | |
3245 | */ | |
ea861dfd | 3246 | static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc) |
1da177e4 | 3247 | { |
42492594 DQ |
3248 | u32 size; |
3249 | int error; | |
3250 | char *context = NULL; | |
20cdef8d | 3251 | struct inode_security_struct *isec; |
d381d8a9 | 3252 | |
8c8570fb DK |
3253 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) |
3254 | return -EOPNOTSUPP; | |
d381d8a9 | 3255 | |
abc69bb6 SS |
3256 | /* |
3257 | * If the caller has CAP_MAC_ADMIN, then get the raw context | |
3258 | * value even if it is not defined by current policy; otherwise, | |
3259 | * use the in-core value under current policy. | |
3260 | * Use the non-auditing forms of the permission checks since | |
3261 | * getxattr may be called by unprivileged processes commonly | |
3262 | * and lack of permission just means that we fall back to the | |
3263 | * in-core context value, not a denial. | |
3264 | */ | |
b1d9e6b0 CS |
3265 | error = cap_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN, |
3266 | SECURITY_CAP_NOAUDIT); | |
3267 | if (!error) | |
3268 | error = cred_has_capability(current_cred(), CAP_MAC_ADMIN, | |
8e4ff6f2 | 3269 | SECURITY_CAP_NOAUDIT, true); |
20cdef8d | 3270 | isec = inode_security(inode); |
abc69bb6 SS |
3271 | if (!error) |
3272 | error = security_sid_to_context_force(isec->sid, &context, | |
3273 | &size); | |
3274 | else | |
3275 | error = security_sid_to_context(isec->sid, &context, &size); | |
42492594 DQ |
3276 | if (error) |
3277 | return error; | |
3278 | error = size; | |
3279 | if (alloc) { | |
3280 | *buffer = context; | |
3281 | goto out_nofree; | |
3282 | } | |
3283 | kfree(context); | |
3284 | out_nofree: | |
3285 | return error; | |
1da177e4 LT |
3286 | } |
3287 | ||
3288 | static int selinux_inode_setsecurity(struct inode *inode, const char *name, | |
828dfe1d | 3289 | const void *value, size_t size, int flags) |
1da177e4 | 3290 | { |
2c97165b | 3291 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
1da177e4 LT |
3292 | u32 newsid; |
3293 | int rc; | |
3294 | ||
3295 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) | |
3296 | return -EOPNOTSUPP; | |
3297 | ||
3298 | if (!value || !size) | |
3299 | return -EACCES; | |
3300 | ||
20ba96ae | 3301 | rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL); |
1da177e4 LT |
3302 | if (rc) |
3303 | return rc; | |
3304 | ||
9287aed2 | 3305 | spin_lock(&isec->lock); |
aa9c2669 | 3306 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3307 | isec->sid = newsid; |
6f3be9f5 | 3308 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3309 | spin_unlock(&isec->lock); |
1da177e4 LT |
3310 | return 0; |
3311 | } | |
3312 | ||
3313 | static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) | |
3314 | { | |
3315 | const int len = sizeof(XATTR_NAME_SELINUX); | |
3316 | if (buffer && len <= buffer_size) | |
3317 | memcpy(buffer, XATTR_NAME_SELINUX, len); | |
3318 | return len; | |
3319 | } | |
3320 | ||
d6335d77 | 3321 | static void selinux_inode_getsecid(struct inode *inode, u32 *secid) |
713a04ae | 3322 | { |
e817c2f3 | 3323 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
713a04ae AD |
3324 | *secid = isec->sid; |
3325 | } | |
3326 | ||
56909eb3 VG |
3327 | static int selinux_inode_copy_up(struct dentry *src, struct cred **new) |
3328 | { | |
3329 | u32 sid; | |
3330 | struct task_security_struct *tsec; | |
3331 | struct cred *new_creds = *new; | |
3332 | ||
3333 | if (new_creds == NULL) { | |
3334 | new_creds = prepare_creds(); | |
3335 | if (!new_creds) | |
3336 | return -ENOMEM; | |
3337 | } | |
3338 | ||
3339 | tsec = new_creds->security; | |
3340 | /* Get label from overlay inode and set it in create_sid */ | |
3341 | selinux_inode_getsecid(d_inode(src), &sid); | |
3342 | tsec->create_sid = sid; | |
3343 | *new = new_creds; | |
3344 | return 0; | |
3345 | } | |
3346 | ||
19472b69 VG |
3347 | static int selinux_inode_copy_up_xattr(const char *name) |
3348 | { | |
3349 | /* The copy_up hook above sets the initial context on an inode, but we | |
3350 | * don't then want to overwrite it by blindly copying all the lower | |
3351 | * xattrs up. Instead, we have to filter out SELinux-related xattrs. | |
3352 | */ | |
3353 | if (strcmp(name, XATTR_NAME_SELINUX) == 0) | |
3354 | return 1; /* Discard */ | |
3355 | /* | |
3356 | * Any other attribute apart from SELINUX is not claimed, supported | |
3357 | * by selinux. | |
3358 | */ | |
3359 | return -EOPNOTSUPP; | |
3360 | } | |
3361 | ||
1da177e4 LT |
3362 | /* file security operations */ |
3363 | ||
788e7dd4 | 3364 | static int selinux_revalidate_file_permission(struct file *file, int mask) |
1da177e4 | 3365 | { |
88e67f3b | 3366 | const struct cred *cred = current_cred(); |
496ad9aa | 3367 | struct inode *inode = file_inode(file); |
1da177e4 | 3368 | |
1da177e4 LT |
3369 | /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ |
3370 | if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) | |
3371 | mask |= MAY_APPEND; | |
3372 | ||
389fb800 PM |
3373 | return file_has_perm(cred, file, |
3374 | file_mask_to_av(inode->i_mode, mask)); | |
1da177e4 LT |
3375 | } |
3376 | ||
788e7dd4 YN |
3377 | static int selinux_file_permission(struct file *file, int mask) |
3378 | { | |
496ad9aa | 3379 | struct inode *inode = file_inode(file); |
20dda18b | 3380 | struct file_security_struct *fsec = file->f_security; |
b197367e | 3381 | struct inode_security_struct *isec; |
20dda18b SS |
3382 | u32 sid = current_sid(); |
3383 | ||
389fb800 | 3384 | if (!mask) |
788e7dd4 YN |
3385 | /* No permission to check. Existence test. */ |
3386 | return 0; | |
788e7dd4 | 3387 | |
b197367e | 3388 | isec = inode_security(inode); |
20dda18b SS |
3389 | if (sid == fsec->sid && fsec->isid == isec->sid && |
3390 | fsec->pseqno == avc_policy_seqno()) | |
83d49856 | 3391 | /* No change since file_open check. */ |
20dda18b SS |
3392 | return 0; |
3393 | ||
788e7dd4 YN |
3394 | return selinux_revalidate_file_permission(file, mask); |
3395 | } | |
3396 | ||
1da177e4 LT |
3397 | static int selinux_file_alloc_security(struct file *file) |
3398 | { | |
3399 | return file_alloc_security(file); | |
3400 | } | |
3401 | ||
3402 | static void selinux_file_free_security(struct file *file) | |
3403 | { | |
3404 | file_free_security(file); | |
3405 | } | |
3406 | ||
fa1aa143 JVS |
3407 | /* |
3408 | * Check whether a task has the ioctl permission and cmd | |
3409 | * operation to an inode. | |
3410 | */ | |
1d2a168a | 3411 | static int ioctl_has_perm(const struct cred *cred, struct file *file, |
fa1aa143 JVS |
3412 | u32 requested, u16 cmd) |
3413 | { | |
3414 | struct common_audit_data ad; | |
3415 | struct file_security_struct *fsec = file->f_security; | |
3416 | struct inode *inode = file_inode(file); | |
20cdef8d | 3417 | struct inode_security_struct *isec; |
fa1aa143 JVS |
3418 | struct lsm_ioctlop_audit ioctl; |
3419 | u32 ssid = cred_sid(cred); | |
3420 | int rc; | |
3421 | u8 driver = cmd >> 8; | |
3422 | u8 xperm = cmd & 0xff; | |
3423 | ||
3424 | ad.type = LSM_AUDIT_DATA_IOCTL_OP; | |
3425 | ad.u.op = &ioctl; | |
3426 | ad.u.op->cmd = cmd; | |
3427 | ad.u.op->path = file->f_path; | |
3428 | ||
3429 | if (ssid != fsec->sid) { | |
3430 | rc = avc_has_perm(ssid, fsec->sid, | |
3431 | SECCLASS_FD, | |
3432 | FD__USE, | |
3433 | &ad); | |
3434 | if (rc) | |
3435 | goto out; | |
3436 | } | |
3437 | ||
3438 | if (unlikely(IS_PRIVATE(inode))) | |
3439 | return 0; | |
3440 | ||
20cdef8d | 3441 | isec = inode_security(inode); |
fa1aa143 JVS |
3442 | rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass, |
3443 | requested, driver, xperm, &ad); | |
3444 | out: | |
3445 | return rc; | |
3446 | } | |
3447 | ||
1da177e4 LT |
3448 | static int selinux_file_ioctl(struct file *file, unsigned int cmd, |
3449 | unsigned long arg) | |
3450 | { | |
88e67f3b | 3451 | const struct cred *cred = current_cred(); |
0b24dcb7 | 3452 | int error = 0; |
1da177e4 | 3453 | |
0b24dcb7 EP |
3454 | switch (cmd) { |
3455 | case FIONREAD: | |
3456 | /* fall through */ | |
3457 | case FIBMAP: | |
3458 | /* fall through */ | |
3459 | case FIGETBSZ: | |
3460 | /* fall through */ | |
2f99c369 | 3461 | case FS_IOC_GETFLAGS: |
0b24dcb7 | 3462 | /* fall through */ |
2f99c369 | 3463 | case FS_IOC_GETVERSION: |
0b24dcb7 EP |
3464 | error = file_has_perm(cred, file, FILE__GETATTR); |
3465 | break; | |
1da177e4 | 3466 | |
2f99c369 | 3467 | case FS_IOC_SETFLAGS: |
0b24dcb7 | 3468 | /* fall through */ |
2f99c369 | 3469 | case FS_IOC_SETVERSION: |
0b24dcb7 EP |
3470 | error = file_has_perm(cred, file, FILE__SETATTR); |
3471 | break; | |
3472 | ||
3473 | /* sys_ioctl() checks */ | |
3474 | case FIONBIO: | |
3475 | /* fall through */ | |
3476 | case FIOASYNC: | |
3477 | error = file_has_perm(cred, file, 0); | |
3478 | break; | |
1da177e4 | 3479 | |
0b24dcb7 EP |
3480 | case KDSKBENT: |
3481 | case KDSKBSENT: | |
6a9de491 | 3482 | error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, |
8e4ff6f2 | 3483 | SECURITY_CAP_AUDIT, true); |
0b24dcb7 EP |
3484 | break; |
3485 | ||
3486 | /* default case assumes that the command will go | |
3487 | * to the file's ioctl() function. | |
3488 | */ | |
3489 | default: | |
fa1aa143 | 3490 | error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); |
0b24dcb7 EP |
3491 | } |
3492 | return error; | |
1da177e4 LT |
3493 | } |
3494 | ||
fcaaade1 SS |
3495 | static int default_noexec; |
3496 | ||
1da177e4 LT |
3497 | static int file_map_prot_check(struct file *file, unsigned long prot, int shared) |
3498 | { | |
88e67f3b | 3499 | const struct cred *cred = current_cred(); |
be0554c9 | 3500 | u32 sid = cred_sid(cred); |
d84f4f99 | 3501 | int rc = 0; |
88e67f3b | 3502 | |
fcaaade1 | 3503 | if (default_noexec && |
892e8cac SS |
3504 | (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) || |
3505 | (!shared && (prot & PROT_WRITE)))) { | |
1da177e4 LT |
3506 | /* |
3507 | * We are making executable an anonymous mapping or a | |
3508 | * private file mapping that will also be writable. | |
3509 | * This has an additional check. | |
3510 | */ | |
be0554c9 SS |
3511 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3512 | PROCESS__EXECMEM, NULL); | |
1da177e4 | 3513 | if (rc) |
d84f4f99 | 3514 | goto error; |
1da177e4 | 3515 | } |
1da177e4 LT |
3516 | |
3517 | if (file) { | |
3518 | /* read access is always possible with a mapping */ | |
3519 | u32 av = FILE__READ; | |
3520 | ||
3521 | /* write access only matters if the mapping is shared */ | |
3522 | if (shared && (prot & PROT_WRITE)) | |
3523 | av |= FILE__WRITE; | |
3524 | ||
3525 | if (prot & PROT_EXEC) | |
3526 | av |= FILE__EXECUTE; | |
3527 | ||
88e67f3b | 3528 | return file_has_perm(cred, file, av); |
1da177e4 | 3529 | } |
d84f4f99 DH |
3530 | |
3531 | error: | |
3532 | return rc; | |
1da177e4 LT |
3533 | } |
3534 | ||
e5467859 | 3535 | static int selinux_mmap_addr(unsigned long addr) |
1da177e4 | 3536 | { |
b1d9e6b0 | 3537 | int rc = 0; |
1da177e4 | 3538 | |
a2551df7 | 3539 | if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { |
98883bfd | 3540 | u32 sid = current_sid(); |
ed032189 EP |
3541 | rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, |
3542 | MEMPROTECT__MMAP_ZERO, NULL); | |
84336d1a EP |
3543 | } |
3544 | ||
98883bfd | 3545 | return rc; |
e5467859 | 3546 | } |
1da177e4 | 3547 | |
e5467859 AV |
3548 | static int selinux_mmap_file(struct file *file, unsigned long reqprot, |
3549 | unsigned long prot, unsigned long flags) | |
3550 | { | |
1da177e4 LT |
3551 | if (selinux_checkreqprot) |
3552 | prot = reqprot; | |
3553 | ||
3554 | return file_map_prot_check(file, prot, | |
3555 | (flags & MAP_TYPE) == MAP_SHARED); | |
3556 | } | |
3557 | ||
3558 | static int selinux_file_mprotect(struct vm_area_struct *vma, | |
3559 | unsigned long reqprot, | |
3560 | unsigned long prot) | |
3561 | { | |
88e67f3b | 3562 | const struct cred *cred = current_cred(); |
be0554c9 | 3563 | u32 sid = cred_sid(cred); |
1da177e4 LT |
3564 | |
3565 | if (selinux_checkreqprot) | |
3566 | prot = reqprot; | |
3567 | ||
fcaaade1 SS |
3568 | if (default_noexec && |
3569 | (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { | |
d541bbee | 3570 | int rc = 0; |
db4c9641 SS |
3571 | if (vma->vm_start >= vma->vm_mm->start_brk && |
3572 | vma->vm_end <= vma->vm_mm->brk) { | |
be0554c9 SS |
3573 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3574 | PROCESS__EXECHEAP, NULL); | |
db4c9641 | 3575 | } else if (!vma->vm_file && |
c2316dbf SS |
3576 | ((vma->vm_start <= vma->vm_mm->start_stack && |
3577 | vma->vm_end >= vma->vm_mm->start_stack) || | |
d17af505 | 3578 | vma_is_stack_for_current(vma))) { |
be0554c9 SS |
3579 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3580 | PROCESS__EXECSTACK, NULL); | |
db4c9641 SS |
3581 | } else if (vma->vm_file && vma->anon_vma) { |
3582 | /* | |
3583 | * We are making executable a file mapping that has | |
3584 | * had some COW done. Since pages might have been | |
3585 | * written, check ability to execute the possibly | |
3586 | * modified content. This typically should only | |
3587 | * occur for text relocations. | |
3588 | */ | |
d84f4f99 | 3589 | rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); |
db4c9641 | 3590 | } |