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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> |
3a976fa6 | 20 | * Copyright (C) 2016 Mellanox Technologies |
1da177e4 LT |
21 | * |
22 | * This program is free software; you can redistribute it and/or modify | |
23 | * it under the terms of the GNU General Public License version 2, | |
828dfe1d | 24 | * as published by the Free Software Foundation. |
1da177e4 LT |
25 | */ |
26 | ||
1da177e4 | 27 | #include <linux/init.h> |
0b24dcb7 | 28 | #include <linux/kd.h> |
1da177e4 | 29 | #include <linux/kernel.h> |
0d094efe | 30 | #include <linux/tracehook.h> |
1da177e4 | 31 | #include <linux/errno.h> |
3f07c014 | 32 | #include <linux/sched/signal.h> |
29930025 | 33 | #include <linux/sched/task.h> |
3c4ed7bd | 34 | #include <linux/lsm_hooks.h> |
1da177e4 LT |
35 | #include <linux/xattr.h> |
36 | #include <linux/capability.h> | |
37 | #include <linux/unistd.h> | |
38 | #include <linux/mm.h> | |
39 | #include <linux/mman.h> | |
40 | #include <linux/slab.h> | |
41 | #include <linux/pagemap.h> | |
0b24dcb7 | 42 | #include <linux/proc_fs.h> |
1da177e4 | 43 | #include <linux/swap.h> |
1da177e4 LT |
44 | #include <linux/spinlock.h> |
45 | #include <linux/syscalls.h> | |
2a7dba39 | 46 | #include <linux/dcache.h> |
1da177e4 | 47 | #include <linux/file.h> |
9f3acc31 | 48 | #include <linux/fdtable.h> |
1da177e4 LT |
49 | #include <linux/namei.h> |
50 | #include <linux/mount.h> | |
1da177e4 LT |
51 | #include <linux/netfilter_ipv4.h> |
52 | #include <linux/netfilter_ipv6.h> | |
53 | #include <linux/tty.h> | |
54 | #include <net/icmp.h> | |
227b60f5 | 55 | #include <net/ip.h> /* for local_port_range[] */ |
1da177e4 | 56 | #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ |
47180068 | 57 | #include <net/inet_connection_sock.h> |
220deb96 | 58 | #include <net/net_namespace.h> |
d621d35e | 59 | #include <net/netlabel.h> |
f5269710 | 60 | #include <linux/uaccess.h> |
1da177e4 | 61 | #include <asm/ioctls.h> |
60063497 | 62 | #include <linux/atomic.h> |
1da177e4 LT |
63 | #include <linux/bitops.h> |
64 | #include <linux/interrupt.h> | |
65 | #include <linux/netdevice.h> /* for network interface checks */ | |
77954983 | 66 | #include <net/netlink.h> |
1da177e4 LT |
67 | #include <linux/tcp.h> |
68 | #include <linux/udp.h> | |
2ee92d46 | 69 | #include <linux/dccp.h> |
1da177e4 LT |
70 | #include <linux/quota.h> |
71 | #include <linux/un.h> /* for Unix socket types */ | |
72 | #include <net/af_unix.h> /* for Unix socket types */ | |
73 | #include <linux/parser.h> | |
74 | #include <linux/nfs_mount.h> | |
75 | #include <net/ipv6.h> | |
76 | #include <linux/hugetlb.h> | |
77 | #include <linux/personality.h> | |
1da177e4 | 78 | #include <linux/audit.h> |
6931dfc9 | 79 | #include <linux/string.h> |
877ce7c1 | 80 | #include <linux/selinux.h> |
23970741 | 81 | #include <linux/mutex.h> |
f06febc9 | 82 | #include <linux/posix-timers.h> |
00234592 | 83 | #include <linux/syslog.h> |
3486740a | 84 | #include <linux/user_namespace.h> |
44fc7ea0 | 85 | #include <linux/export.h> |
40401530 AV |
86 | #include <linux/msg.h> |
87 | #include <linux/shm.h> | |
1da177e4 LT |
88 | |
89 | #include "avc.h" | |
90 | #include "objsec.h" | |
91 | #include "netif.h" | |
224dfbd8 | 92 | #include "netnode.h" |
3e112172 | 93 | #include "netport.h" |
409dcf31 | 94 | #include "ibpkey.h" |
d28d1e08 | 95 | #include "xfrm.h" |
c60475bf | 96 | #include "netlabel.h" |
9d57a7f9 | 97 | #include "audit.h" |
7b98a585 | 98 | #include "avc_ss.h" |
1da177e4 | 99 | |
d621d35e | 100 | /* SECMARK reference count */ |
56a4ca99 | 101 | static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); |
d621d35e | 102 | |
1da177e4 | 103 | #ifdef CONFIG_SECURITY_SELINUX_DEVELOP |
828dfe1d | 104 | int selinux_enforcing; |
1da177e4 LT |
105 | |
106 | static int __init enforcing_setup(char *str) | |
107 | { | |
f5269710 | 108 | unsigned long enforcing; |
29707b20 | 109 | if (!kstrtoul(str, 0, &enforcing)) |
f5269710 | 110 | selinux_enforcing = enforcing ? 1 : 0; |
1da177e4 LT |
111 | return 1; |
112 | } | |
113 | __setup("enforcing=", enforcing_setup); | |
114 | #endif | |
115 | ||
116 | #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM | |
117 | int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; | |
118 | ||
119 | static int __init selinux_enabled_setup(char *str) | |
120 | { | |
f5269710 | 121 | unsigned long enabled; |
29707b20 | 122 | if (!kstrtoul(str, 0, &enabled)) |
f5269710 | 123 | selinux_enabled = enabled ? 1 : 0; |
1da177e4 LT |
124 | return 1; |
125 | } | |
126 | __setup("selinux=", selinux_enabled_setup); | |
30d55280 SS |
127 | #else |
128 | int selinux_enabled = 1; | |
1da177e4 LT |
129 | #endif |
130 | ||
33132849 JS |
131 | static struct kmem_cache *sel_inode_cache; |
132 | ||
d621d35e PM |
133 | /** |
134 | * selinux_secmark_enabled - Check to see if SECMARK is currently enabled | |
135 | * | |
136 | * Description: | |
137 | * This function checks the SECMARK reference counter to see if any SECMARK | |
138 | * targets are currently configured, if the reference counter is greater than | |
139 | * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is | |
2be4d74f CP |
140 | * enabled, false (0) if SECMARK is disabled. If the always_check_network |
141 | * policy capability is enabled, SECMARK is always considered enabled. | |
d621d35e PM |
142 | * |
143 | */ | |
144 | static int selinux_secmark_enabled(void) | |
145 | { | |
2be4d74f CP |
146 | return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount)); |
147 | } | |
148 | ||
149 | /** | |
150 | * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled | |
151 | * | |
152 | * Description: | |
153 | * This function checks if NetLabel or labeled IPSEC is enabled. Returns true | |
154 | * (1) if any are enabled or false (0) if neither are enabled. If the | |
155 | * always_check_network policy capability is enabled, peer labeling | |
156 | * is always considered enabled. | |
157 | * | |
158 | */ | |
159 | static int selinux_peerlbl_enabled(void) | |
160 | { | |
161 | return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled()); | |
d621d35e PM |
162 | } |
163 | ||
615e51fd PM |
164 | static int selinux_netcache_avc_callback(u32 event) |
165 | { | |
166 | if (event == AVC_CALLBACK_RESET) { | |
167 | sel_netif_flush(); | |
168 | sel_netnode_flush(); | |
169 | sel_netport_flush(); | |
170 | synchronize_net(); | |
171 | } | |
172 | return 0; | |
173 | } | |
174 | ||
8f408ab6 DJ |
175 | static int selinux_lsm_notifier_avc_callback(u32 event) |
176 | { | |
409dcf31 DJ |
177 | if (event == AVC_CALLBACK_RESET) { |
178 | sel_ib_pkey_flush(); | |
8f408ab6 | 179 | call_lsm_notifier(LSM_POLICY_CHANGE, NULL); |
409dcf31 | 180 | } |
8f408ab6 DJ |
181 | |
182 | return 0; | |
183 | } | |
184 | ||
d84f4f99 DH |
185 | /* |
186 | * initialise the security for the init task | |
187 | */ | |
188 | static void cred_init_security(void) | |
1da177e4 | 189 | { |
3b11a1de | 190 | struct cred *cred = (struct cred *) current->real_cred; |
1da177e4 LT |
191 | struct task_security_struct *tsec; |
192 | ||
98738d70 CS |
193 | lsm_early_cred(cred); |
194 | tsec = selinux_cred(cred); | |
d84f4f99 | 195 | tsec->osid = tsec->sid = SECINITSID_KERNEL; |
1da177e4 LT |
196 | } |
197 | ||
88e67f3b DH |
198 | /* |
199 | * get the security ID of a set of credentials | |
200 | */ | |
201 | static inline u32 cred_sid(const struct cred *cred) | |
202 | { | |
203 | const struct task_security_struct *tsec; | |
204 | ||
98738d70 | 205 | tsec = selinux_cred(cred); |
88e67f3b DH |
206 | return tsec->sid; |
207 | } | |
208 | ||
275bb41e | 209 | /* |
3b11a1de | 210 | * get the objective security ID of a task |
275bb41e DH |
211 | */ |
212 | static inline u32 task_sid(const struct task_struct *task) | |
213 | { | |
275bb41e DH |
214 | u32 sid; |
215 | ||
216 | rcu_read_lock(); | |
88e67f3b | 217 | sid = cred_sid(__task_cred(task)); |
275bb41e DH |
218 | rcu_read_unlock(); |
219 | return sid; | |
220 | } | |
221 | ||
88e67f3b DH |
222 | /* Allocate and free functions for each kind of security blob. */ |
223 | ||
1da177e4 LT |
224 | static int inode_alloc_security(struct inode *inode) |
225 | { | |
33132849 | 226 | struct inode_security_struct *isec; |
275bb41e | 227 | u32 sid = current_sid(); |
1da177e4 | 228 | |
33132849 JS |
229 | isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); |
230 | if (!isec) | |
231 | return -ENOMEM; | |
232 | ||
9287aed2 | 233 | spin_lock_init(&isec->lock); |
1da177e4 | 234 | INIT_LIST_HEAD(&isec->list); |
1da177e4 LT |
235 | isec->inode = inode; |
236 | isec->sid = SECINITSID_UNLABELED; | |
237 | isec->sclass = SECCLASS_FILE; | |
275bb41e | 238 | isec->task_sid = sid; |
42059112 | 239 | isec->initialized = LABEL_INVALID; |
33132849 | 240 | inode->i_security = isec; |
1da177e4 LT |
241 | |
242 | return 0; | |
243 | } | |
244 | ||
5d226df4 AG |
245 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); |
246 | ||
247 | /* | |
248 | * Try reloading inode security labels that have been marked as invalid. The | |
249 | * @may_sleep parameter indicates when sleeping and thus reloading labels is | |
42059112 | 250 | * allowed; when set to false, returns -ECHILD when the label is |
5d226df4 AG |
251 | * invalid. The @opt_dentry parameter should be set to a dentry of the inode; |
252 | * when no dentry is available, set it to NULL instead. | |
253 | */ | |
254 | static int __inode_security_revalidate(struct inode *inode, | |
255 | struct dentry *opt_dentry, | |
256 | bool may_sleep) | |
257 | { | |
33132849 | 258 | struct inode_security_struct *isec = inode->i_security; |
5d226df4 AG |
259 | |
260 | might_sleep_if(may_sleep); | |
261 | ||
1ac42476 | 262 | if (ss_initialized && isec->initialized != LABEL_INITIALIZED) { |
5d226df4 AG |
263 | if (!may_sleep) |
264 | return -ECHILD; | |
265 | ||
266 | /* | |
267 | * Try reloading the inode security label. This will fail if | |
268 | * @opt_dentry is NULL and no dentry for this inode can be | |
269 | * found; in that case, continue using the old label. | |
270 | */ | |
271 | inode_doinit_with_dentry(inode, opt_dentry); | |
272 | } | |
273 | return 0; | |
274 | } | |
275 | ||
5d226df4 AG |
276 | static struct inode_security_struct *inode_security_novalidate(struct inode *inode) |
277 | { | |
33132849 | 278 | return inode->i_security; |
5d226df4 AG |
279 | } |
280 | ||
281 | static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu) | |
282 | { | |
283 | int error; | |
284 | ||
285 | error = __inode_security_revalidate(inode, NULL, !rcu); | |
286 | if (error) | |
287 | return ERR_PTR(error); | |
33132849 | 288 | return inode->i_security; |
5d226df4 AG |
289 | } |
290 | ||
83da53c5 AG |
291 | /* |
292 | * Get the security label of an inode. | |
293 | */ | |
294 | static struct inode_security_struct *inode_security(struct inode *inode) | |
295 | { | |
5d226df4 | 296 | __inode_security_revalidate(inode, NULL, true); |
33132849 | 297 | return inode->i_security; |
83da53c5 AG |
298 | } |
299 | ||
2c97165b PM |
300 | static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry) |
301 | { | |
302 | struct inode *inode = d_backing_inode(dentry); | |
303 | ||
33132849 | 304 | return inode->i_security; |
2c97165b PM |
305 | } |
306 | ||
83da53c5 AG |
307 | /* |
308 | * Get the security label of a dentry's backing inode. | |
309 | */ | |
310 | static struct inode_security_struct *backing_inode_security(struct dentry *dentry) | |
311 | { | |
312 | struct inode *inode = d_backing_inode(dentry); | |
313 | ||
5d226df4 | 314 | __inode_security_revalidate(inode, dentry, true); |
33132849 JS |
315 | return inode->i_security; |
316 | } | |
317 | ||
318 | static void inode_free_rcu(struct rcu_head *head) | |
319 | { | |
320 | struct inode_security_struct *isec; | |
321 | ||
322 | isec = container_of(head, struct inode_security_struct, rcu); | |
323 | kmem_cache_free(sel_inode_cache, isec); | |
3dc91d43 SR |
324 | } |
325 | ||
1da177e4 LT |
326 | static void inode_free_security(struct inode *inode) |
327 | { | |
33132849 JS |
328 | struct inode_security_struct *isec = inode->i_security; |
329 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; | |
1da177e4 | 330 | |
9629d04a WL |
331 | /* |
332 | * As not all inode security structures are in a list, we check for | |
333 | * empty list outside of the lock to make sure that we won't waste | |
334 | * time taking a lock doing nothing. | |
335 | * | |
336 | * The list_del_init() function can be safely called more than once. | |
337 | * It should not be possible for this function to be called with | |
338 | * concurrent list_add(), but for better safety against future changes | |
339 | * in the code, we use list_empty_careful() here. | |
340 | */ | |
341 | if (!list_empty_careful(&isec->list)) { | |
342 | spin_lock(&sbsec->isec_lock); | |
1da177e4 | 343 | list_del_init(&isec->list); |
9629d04a WL |
344 | spin_unlock(&sbsec->isec_lock); |
345 | } | |
33132849 JS |
346 | |
347 | /* | |
348 | * The inode may still be referenced in a path walk and | |
349 | * a call to selinux_inode_permission() can be made | |
350 | * after inode_free_security() is called. Ideally, the VFS | |
351 | * wouldn't do this, but fixing that is a much harder | |
352 | * job. For now, simply free the i_security via RCU, and | |
353 | * leave the current inode->i_security pointer intact. | |
354 | * The inode will be freed after the RCU grace period too. | |
355 | */ | |
356 | call_rcu(&isec->rcu, inode_free_rcu); | |
1da177e4 LT |
357 | } |
358 | ||
359 | static int file_alloc_security(struct file *file) | |
360 | { | |
004c5200 | 361 | struct file_security_struct *fsec = selinux_file(file); |
275bb41e | 362 | u32 sid = current_sid(); |
1da177e4 | 363 | |
275bb41e DH |
364 | fsec->sid = sid; |
365 | fsec->fown_sid = sid; | |
1da177e4 LT |
366 | |
367 | return 0; | |
368 | } | |
369 | ||
1da177e4 LT |
370 | static int superblock_alloc_security(struct super_block *sb) |
371 | { | |
33132849 JS |
372 | struct superblock_security_struct *sbsec; |
373 | ||
374 | sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); | |
375 | if (!sbsec) | |
376 | return -ENOMEM; | |
1da177e4 | 377 | |
bc7e982b | 378 | mutex_init(&sbsec->lock); |
1da177e4 LT |
379 | INIT_LIST_HEAD(&sbsec->isec_head); |
380 | spin_lock_init(&sbsec->isec_lock); | |
1da177e4 LT |
381 | sbsec->sb = sb; |
382 | sbsec->sid = SECINITSID_UNLABELED; | |
383 | sbsec->def_sid = SECINITSID_FILE; | |
c312feb2 | 384 | sbsec->mntpoint_sid = SECINITSID_UNLABELED; |
33132849 | 385 | sb->s_security = sbsec; |
1da177e4 LT |
386 | |
387 | return 0; | |
388 | } | |
389 | ||
33132849 JS |
390 | static void superblock_free_security(struct super_block *sb) |
391 | { | |
392 | struct superblock_security_struct *sbsec = sb->s_security; | |
393 | sb->s_security = NULL; | |
394 | kfree(sbsec); | |
395 | } | |
396 | ||
1da177e4 LT |
397 | static inline int inode_doinit(struct inode *inode) |
398 | { | |
399 | return inode_doinit_with_dentry(inode, NULL); | |
400 | } | |
401 | ||
402 | enum { | |
31e87930 | 403 | Opt_error = -1, |
1da177e4 LT |
404 | Opt_context = 1, |
405 | Opt_fscontext = 2, | |
c9180a57 EP |
406 | Opt_defcontext = 3, |
407 | Opt_rootcontext = 4, | |
11689d47 | 408 | Opt_labelsupport = 5, |
d355987f | 409 | Opt_nextmntopt = 6, |
1da177e4 LT |
410 | }; |
411 | ||
d355987f EP |
412 | #define NUM_SEL_MNT_OPTS (Opt_nextmntopt - 1) |
413 | ||
a447c093 | 414 | static const match_table_t tokens = { |
832cbd9a EP |
415 | {Opt_context, CONTEXT_STR "%s"}, |
416 | {Opt_fscontext, FSCONTEXT_STR "%s"}, | |
417 | {Opt_defcontext, DEFCONTEXT_STR "%s"}, | |
418 | {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, | |
11689d47 | 419 | {Opt_labelsupport, LABELSUPP_STR}, |
31e87930 | 420 | {Opt_error, NULL}, |
1da177e4 LT |
421 | }; |
422 | ||
423 | #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" | |
424 | ||
c312feb2 EP |
425 | static int may_context_mount_sb_relabel(u32 sid, |
426 | struct superblock_security_struct *sbsec, | |
275bb41e | 427 | const struct cred *cred) |
c312feb2 | 428 | { |
98738d70 | 429 | const struct task_security_struct *tsec = selinux_cred(cred); |
c312feb2 EP |
430 | int rc; |
431 | ||
432 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
433 | FILESYSTEM__RELABELFROM, NULL); | |
434 | if (rc) | |
435 | return rc; | |
436 | ||
437 | rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, | |
438 | FILESYSTEM__RELABELTO, NULL); | |
439 | return rc; | |
440 | } | |
441 | ||
0808925e EP |
442 | static int may_context_mount_inode_relabel(u32 sid, |
443 | struct superblock_security_struct *sbsec, | |
275bb41e | 444 | const struct cred *cred) |
0808925e | 445 | { |
98738d70 | 446 | const struct task_security_struct *tsec = selinux_cred(cred); |
0808925e EP |
447 | int rc; |
448 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
449 | FILESYSTEM__RELABELFROM, NULL); | |
450 | if (rc) | |
451 | return rc; | |
452 | ||
453 | rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
454 | FILESYSTEM__ASSOCIATE, NULL); | |
455 | return rc; | |
456 | } | |
457 | ||
b43e725d EP |
458 | static int selinux_is_sblabel_mnt(struct super_block *sb) |
459 | { | |
33132849 | 460 | struct superblock_security_struct *sbsec = sb->s_security; |
b43e725d | 461 | |
d5f3a5f6 MS |
462 | return sbsec->behavior == SECURITY_FS_USE_XATTR || |
463 | sbsec->behavior == SECURITY_FS_USE_TRANS || | |
464 | sbsec->behavior == SECURITY_FS_USE_TASK || | |
9fc2b4b4 | 465 | sbsec->behavior == SECURITY_FS_USE_NATIVE || |
d5f3a5f6 MS |
466 | /* Special handling. Genfs but also in-core setxattr handler */ |
467 | !strcmp(sb->s_type->name, "sysfs") || | |
468 | !strcmp(sb->s_type->name, "pstore") || | |
469 | !strcmp(sb->s_type->name, "debugfs") || | |
a2c7c6fb | 470 | !strcmp(sb->s_type->name, "tracefs") || |
2651225b SS |
471 | !strcmp(sb->s_type->name, "rootfs") || |
472 | (selinux_policycap_cgroupseclabel && | |
473 | (!strcmp(sb->s_type->name, "cgroup") || | |
474 | !strcmp(sb->s_type->name, "cgroup2"))); | |
b43e725d EP |
475 | } |
476 | ||
c9180a57 | 477 | static int sb_finish_set_opts(struct super_block *sb) |
1da177e4 | 478 | { |
33132849 | 479 | struct superblock_security_struct *sbsec = sb->s_security; |
c9180a57 | 480 | struct dentry *root = sb->s_root; |
c6f493d6 | 481 | struct inode *root_inode = d_backing_inode(root); |
c9180a57 | 482 | int rc = 0; |
1da177e4 | 483 | |
c9180a57 EP |
484 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { |
485 | /* Make sure that the xattr handler exists and that no | |
486 | error other than -ENODATA is returned by getxattr on | |
487 | the root directory. -ENODATA is ok, as this may be | |
488 | the first boot of the SELinux kernel before we have | |
489 | assigned xattr values to the filesystem. */ | |
5d6c3191 | 490 | if (!(root_inode->i_opflags & IOP_XATTR)) { |
29b1deb2 LT |
491 | printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " |
492 | "xattr support\n", sb->s_id, sb->s_type->name); | |
c9180a57 EP |
493 | rc = -EOPNOTSUPP; |
494 | goto out; | |
495 | } | |
5d6c3191 AG |
496 | |
497 | rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0); | |
c9180a57 EP |
498 | if (rc < 0 && rc != -ENODATA) { |
499 | if (rc == -EOPNOTSUPP) | |
500 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
29b1deb2 LT |
501 | "%s) has no security xattr handler\n", |
502 | sb->s_id, sb->s_type->name); | |
c9180a57 EP |
503 | else |
504 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
29b1deb2 LT |
505 | "%s) getxattr errno %d\n", sb->s_id, |
506 | sb->s_type->name, -rc); | |
c9180a57 EP |
507 | goto out; |
508 | } | |
509 | } | |
1da177e4 | 510 | |
eadcabc6 | 511 | sbsec->flags |= SE_SBINITIALIZED; |
0b4d3452 SM |
512 | |
513 | /* | |
514 | * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply | |
515 | * leave the flag untouched because sb_clone_mnt_opts might be handing | |
516 | * us a superblock that needs the flag to be cleared. | |
517 | */ | |
b43e725d | 518 | if (selinux_is_sblabel_mnt(sb)) |
12f348b9 | 519 | sbsec->flags |= SBLABEL_MNT; |
0b4d3452 SM |
520 | else |
521 | sbsec->flags &= ~SBLABEL_MNT; | |
ddd29ec6 | 522 | |
c9180a57 EP |
523 | /* Initialize the root inode. */ |
524 | rc = inode_doinit_with_dentry(root_inode, root); | |
1da177e4 | 525 | |
c9180a57 EP |
526 | /* Initialize any other inodes associated with the superblock, e.g. |
527 | inodes created prior to initial policy load or inodes created | |
528 | during get_sb by a pseudo filesystem that directly | |
529 | populates itself. */ | |
530 | spin_lock(&sbsec->isec_lock); | |
531 | next_inode: | |
532 | if (!list_empty(&sbsec->isec_head)) { | |
533 | struct inode_security_struct *isec = | |
534 | list_entry(sbsec->isec_head.next, | |
535 | struct inode_security_struct, list); | |
536 | struct inode *inode = isec->inode; | |
923190d3 | 537 | list_del_init(&isec->list); |
c9180a57 EP |
538 | spin_unlock(&sbsec->isec_lock); |
539 | inode = igrab(inode); | |
540 | if (inode) { | |
541 | if (!IS_PRIVATE(inode)) | |
542 | inode_doinit(inode); | |
543 | iput(inode); | |
544 | } | |
545 | spin_lock(&sbsec->isec_lock); | |
c9180a57 EP |
546 | goto next_inode; |
547 | } | |
548 | spin_unlock(&sbsec->isec_lock); | |
549 | out: | |
550 | return rc; | |
551 | } | |
1da177e4 | 552 | |
c9180a57 EP |
553 | /* |
554 | * This function should allow an FS to ask what it's mount security | |
555 | * options were so it can use those later for submounts, displaying | |
556 | * mount options, or whatever. | |
557 | */ | |
558 | static int selinux_get_mnt_opts(const struct super_block *sb, | |
e0007529 | 559 | struct security_mnt_opts *opts) |
c9180a57 EP |
560 | { |
561 | int rc = 0, i; | |
33132849 | 562 | struct superblock_security_struct *sbsec = sb->s_security; |
c9180a57 EP |
563 | char *context = NULL; |
564 | u32 len; | |
565 | char tmp; | |
1da177e4 | 566 | |
e0007529 | 567 | security_init_mnt_opts(opts); |
1da177e4 | 568 | |
0d90a7ec | 569 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
c9180a57 | 570 | return -EINVAL; |
1da177e4 | 571 | |
c9180a57 EP |
572 | if (!ss_initialized) |
573 | return -EINVAL; | |
1da177e4 | 574 | |
af8e50cc EP |
575 | /* make sure we always check enough bits to cover the mask */ |
576 | BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS)); | |
577 | ||
0d90a7ec | 578 | tmp = sbsec->flags & SE_MNTMASK; |
c9180a57 | 579 | /* count the number of mount options for this sb */ |
af8e50cc | 580 | for (i = 0; i < NUM_SEL_MNT_OPTS; i++) { |
c9180a57 | 581 | if (tmp & 0x01) |
e0007529 | 582 | opts->num_mnt_opts++; |
c9180a57 EP |
583 | tmp >>= 1; |
584 | } | |
11689d47 | 585 | /* Check if the Label support flag is set */ |
0b4bdb35 | 586 | if (sbsec->flags & SBLABEL_MNT) |
11689d47 | 587 | opts->num_mnt_opts++; |
1da177e4 | 588 | |
e0007529 EP |
589 | opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); |
590 | if (!opts->mnt_opts) { | |
c9180a57 EP |
591 | rc = -ENOMEM; |
592 | goto out_free; | |
593 | } | |
1da177e4 | 594 | |
e0007529 EP |
595 | opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); |
596 | if (!opts->mnt_opts_flags) { | |
c9180a57 EP |
597 | rc = -ENOMEM; |
598 | goto out_free; | |
599 | } | |
1da177e4 | 600 | |
c9180a57 EP |
601 | i = 0; |
602 | if (sbsec->flags & FSCONTEXT_MNT) { | |
603 | rc = security_sid_to_context(sbsec->sid, &context, &len); | |
604 | if (rc) | |
605 | goto out_free; | |
e0007529 EP |
606 | opts->mnt_opts[i] = context; |
607 | opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; | |
c9180a57 EP |
608 | } |
609 | if (sbsec->flags & CONTEXT_MNT) { | |
610 | rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); | |
611 | if (rc) | |
612 | goto out_free; | |
e0007529 EP |
613 | opts->mnt_opts[i] = context; |
614 | opts->mnt_opts_flags[i++] = CONTEXT_MNT; | |
c9180a57 EP |
615 | } |
616 | if (sbsec->flags & DEFCONTEXT_MNT) { | |
617 | rc = security_sid_to_context(sbsec->def_sid, &context, &len); | |
618 | if (rc) | |
619 | goto out_free; | |
e0007529 EP |
620 | opts->mnt_opts[i] = context; |
621 | opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; | |
c9180a57 EP |
622 | } |
623 | if (sbsec->flags & ROOTCONTEXT_MNT) { | |
83da53c5 | 624 | struct dentry *root = sbsec->sb->s_root; |
33132849 | 625 | struct inode_security_struct *isec = backing_inode_security(root); |
0808925e | 626 | |
c9180a57 EP |
627 | rc = security_sid_to_context(isec->sid, &context, &len); |
628 | if (rc) | |
629 | goto out_free; | |
e0007529 EP |
630 | opts->mnt_opts[i] = context; |
631 | opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; | |
c9180a57 | 632 | } |
12f348b9 | 633 | if (sbsec->flags & SBLABEL_MNT) { |
11689d47 | 634 | opts->mnt_opts[i] = NULL; |
12f348b9 | 635 | opts->mnt_opts_flags[i++] = SBLABEL_MNT; |
11689d47 | 636 | } |
1da177e4 | 637 | |
e0007529 | 638 | BUG_ON(i != opts->num_mnt_opts); |
1da177e4 | 639 | |
c9180a57 EP |
640 | return 0; |
641 | ||
642 | out_free: | |
e0007529 | 643 | security_free_mnt_opts(opts); |
c9180a57 EP |
644 | return rc; |
645 | } | |
1da177e4 | 646 | |
c9180a57 EP |
647 | static int bad_option(struct superblock_security_struct *sbsec, char flag, |
648 | u32 old_sid, u32 new_sid) | |
649 | { | |
0d90a7ec DQ |
650 | char mnt_flags = sbsec->flags & SE_MNTMASK; |
651 | ||
c9180a57 | 652 | /* check if the old mount command had the same options */ |
0d90a7ec | 653 | if (sbsec->flags & SE_SBINITIALIZED) |
c9180a57 EP |
654 | if (!(sbsec->flags & flag) || |
655 | (old_sid != new_sid)) | |
656 | return 1; | |
657 | ||
658 | /* check if we were passed the same options twice, | |
659 | * aka someone passed context=a,context=b | |
660 | */ | |
0d90a7ec DQ |
661 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
662 | if (mnt_flags & flag) | |
c9180a57 EP |
663 | return 1; |
664 | return 0; | |
665 | } | |
e0007529 | 666 | |
c9180a57 EP |
667 | /* |
668 | * Allow filesystems with binary mount data to explicitly set mount point | |
669 | * labeling information. | |
670 | */ | |
e0007529 | 671 | static int selinux_set_mnt_opts(struct super_block *sb, |
649f6e77 DQ |
672 | struct security_mnt_opts *opts, |
673 | unsigned long kern_flags, | |
674 | unsigned long *set_kern_flags) | |
c9180a57 | 675 | { |
275bb41e | 676 | const struct cred *cred = current_cred(); |
c9180a57 | 677 | int rc = 0, i; |
33132849 | 678 | struct superblock_security_struct *sbsec = sb->s_security; |
29b1deb2 | 679 | const char *name = sb->s_type->name; |
83da53c5 | 680 | struct dentry *root = sbsec->sb->s_root; |
2c97165b | 681 | struct inode_security_struct *root_isec; |
c9180a57 EP |
682 | u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; |
683 | u32 defcontext_sid = 0; | |
e0007529 EP |
684 | char **mount_options = opts->mnt_opts; |
685 | int *flags = opts->mnt_opts_flags; | |
686 | int num_opts = opts->num_mnt_opts; | |
c9180a57 EP |
687 | |
688 | mutex_lock(&sbsec->lock); | |
689 | ||
690 | if (!ss_initialized) { | |
691 | if (!num_opts) { | |
692 | /* Defer initialization until selinux_complete_init, | |
693 | after the initial policy is loaded and the security | |
694 | server is ready to handle calls. */ | |
c9180a57 EP |
695 | goto out; |
696 | } | |
697 | rc = -EINVAL; | |
744ba35e EP |
698 | printk(KERN_WARNING "SELinux: Unable to set superblock options " |
699 | "before the security server is initialized\n"); | |
1da177e4 | 700 | goto out; |
c9180a57 | 701 | } |
649f6e77 DQ |
702 | if (kern_flags && !set_kern_flags) { |
703 | /* Specifying internal flags without providing a place to | |
704 | * place the results is not allowed */ | |
705 | rc = -EINVAL; | |
706 | goto out; | |
707 | } | |
1da177e4 | 708 | |
e0007529 EP |
709 | /* |
710 | * Binary mount data FS will come through this function twice. Once | |
711 | * from an explicit call and once from the generic calls from the vfs. | |
712 | * Since the generic VFS calls will not contain any security mount data | |
713 | * we need to skip the double mount verification. | |
714 | * | |
715 | * This does open a hole in which we will not notice if the first | |
716 | * mount using this sb set explict options and a second mount using | |
717 | * this sb does not set any security options. (The first options | |
718 | * will be used for both mounts) | |
719 | */ | |
0d90a7ec | 720 | if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) |
e0007529 | 721 | && (num_opts == 0)) |
f5269710 | 722 | goto out; |
e0007529 | 723 | |
2c97165b PM |
724 | root_isec = backing_inode_security_novalidate(root); |
725 | ||
c9180a57 EP |
726 | /* |
727 | * parse the mount options, check if they are valid sids. | |
728 | * also check if someone is trying to mount the same sb more | |
729 | * than once with different security options. | |
730 | */ | |
731 | for (i = 0; i < num_opts; i++) { | |
732 | u32 sid; | |
11689d47 | 733 | |
12f348b9 | 734 | if (flags[i] == SBLABEL_MNT) |
11689d47 | 735 | continue; |
44be2f65 | 736 | rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL); |
1da177e4 | 737 | if (rc) { |
44be2f65 | 738 | printk(KERN_WARNING "SELinux: security_context_str_to_sid" |
29b1deb2 LT |
739 | "(%s) failed for (dev %s, type %s) errno=%d\n", |
740 | mount_options[i], sb->s_id, name, rc); | |
c9180a57 EP |
741 | goto out; |
742 | } | |
743 | switch (flags[i]) { | |
744 | case FSCONTEXT_MNT: | |
745 | fscontext_sid = sid; | |
746 | ||
747 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, | |
748 | fscontext_sid)) | |
749 | goto out_double_mount; | |
750 | ||
751 | sbsec->flags |= FSCONTEXT_MNT; | |
752 | break; | |
753 | case CONTEXT_MNT: | |
754 | context_sid = sid; | |
755 | ||
756 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, | |
757 | context_sid)) | |
758 | goto out_double_mount; | |
759 | ||
760 | sbsec->flags |= CONTEXT_MNT; | |
761 | break; | |
762 | case ROOTCONTEXT_MNT: | |
763 | rootcontext_sid = sid; | |
764 | ||
765 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, | |
766 | rootcontext_sid)) | |
767 | goto out_double_mount; | |
768 | ||
769 | sbsec->flags |= ROOTCONTEXT_MNT; | |
770 | ||
771 | break; | |
772 | case DEFCONTEXT_MNT: | |
773 | defcontext_sid = sid; | |
774 | ||
775 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, | |
776 | defcontext_sid)) | |
777 | goto out_double_mount; | |
778 | ||
779 | sbsec->flags |= DEFCONTEXT_MNT; | |
780 | ||
781 | break; | |
782 | default: | |
783 | rc = -EINVAL; | |
784 | goto out; | |
1da177e4 | 785 | } |
c9180a57 EP |
786 | } |
787 | ||
0d90a7ec | 788 | if (sbsec->flags & SE_SBINITIALIZED) { |
c9180a57 | 789 | /* previously mounted with options, but not on this attempt? */ |
0d90a7ec | 790 | if ((sbsec->flags & SE_MNTMASK) && !num_opts) |
c9180a57 EP |
791 | goto out_double_mount; |
792 | rc = 0; | |
793 | goto out; | |
794 | } | |
795 | ||
089be43e | 796 | if (strcmp(sb->s_type->name, "proc") == 0) |
134509d5 SS |
797 | sbsec->flags |= SE_SBPROC | SE_SBGENFS; |
798 | ||
8e014720 | 799 | if (!strcmp(sb->s_type->name, "debugfs") || |
6a391183 | 800 | !strcmp(sb->s_type->name, "tracefs") || |
8e014720 SS |
801 | !strcmp(sb->s_type->name, "sysfs") || |
802 | !strcmp(sb->s_type->name, "pstore")) | |
134509d5 | 803 | sbsec->flags |= SE_SBGENFS; |
c9180a57 | 804 | |
eb9ae686 DQ |
805 | if (!sbsec->behavior) { |
806 | /* | |
807 | * Determine the labeling behavior to use for this | |
808 | * filesystem type. | |
809 | */ | |
98f700f3 | 810 | rc = security_fs_use(sb); |
eb9ae686 DQ |
811 | if (rc) { |
812 | printk(KERN_WARNING | |
813 | "%s: security_fs_use(%s) returned %d\n", | |
814 | __func__, sb->s_type->name, rc); | |
815 | goto out; | |
816 | } | |
c9180a57 | 817 | } |
aad82892 SF |
818 | |
819 | /* | |
01593d32 SS |
820 | * If this is a user namespace mount and the filesystem type is not |
821 | * explicitly whitelisted, then no contexts are allowed on the command | |
822 | * line and security labels must be ignored. | |
aad82892 | 823 | */ |
01593d32 SS |
824 | if (sb->s_user_ns != &init_user_ns && |
825 | strcmp(sb->s_type->name, "tmpfs") && | |
826 | strcmp(sb->s_type->name, "ramfs") && | |
827 | strcmp(sb->s_type->name, "devpts")) { | |
aad82892 SF |
828 | if (context_sid || fscontext_sid || rootcontext_sid || |
829 | defcontext_sid) { | |
830 | rc = -EACCES; | |
831 | goto out; | |
832 | } | |
833 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { | |
834 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; | |
835 | rc = security_transition_sid(current_sid(), current_sid(), | |
836 | SECCLASS_FILE, NULL, | |
837 | &sbsec->mntpoint_sid); | |
838 | if (rc) | |
839 | goto out; | |
840 | } | |
841 | goto out_set_opts; | |
842 | } | |
843 | ||
c9180a57 EP |
844 | /* sets the context of the superblock for the fs being mounted. */ |
845 | if (fscontext_sid) { | |
275bb41e | 846 | rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); |
1da177e4 | 847 | if (rc) |
c9180a57 | 848 | goto out; |
1da177e4 | 849 | |
c9180a57 | 850 | sbsec->sid = fscontext_sid; |
c312feb2 EP |
851 | } |
852 | ||
853 | /* | |
854 | * Switch to using mount point labeling behavior. | |
855 | * sets the label used on all file below the mountpoint, and will set | |
856 | * the superblock context if not already set. | |
857 | */ | |
eb9ae686 DQ |
858 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) { |
859 | sbsec->behavior = SECURITY_FS_USE_NATIVE; | |
860 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
861 | } | |
862 | ||
c9180a57 EP |
863 | if (context_sid) { |
864 | if (!fscontext_sid) { | |
275bb41e DH |
865 | rc = may_context_mount_sb_relabel(context_sid, sbsec, |
866 | cred); | |
b04ea3ce | 867 | if (rc) |
c9180a57 EP |
868 | goto out; |
869 | sbsec->sid = context_sid; | |
b04ea3ce | 870 | } else { |
275bb41e DH |
871 | rc = may_context_mount_inode_relabel(context_sid, sbsec, |
872 | cred); | |
b04ea3ce | 873 | if (rc) |
c9180a57 | 874 | goto out; |
b04ea3ce | 875 | } |
c9180a57 EP |
876 | if (!rootcontext_sid) |
877 | rootcontext_sid = context_sid; | |
1da177e4 | 878 | |
c9180a57 | 879 | sbsec->mntpoint_sid = context_sid; |
c312feb2 | 880 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; |
1da177e4 LT |
881 | } |
882 | ||
c9180a57 | 883 | if (rootcontext_sid) { |
275bb41e DH |
884 | rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, |
885 | cred); | |
0808925e | 886 | if (rc) |
c9180a57 | 887 | goto out; |
0808925e | 888 | |
c9180a57 | 889 | root_isec->sid = rootcontext_sid; |
6f3be9f5 | 890 | root_isec->initialized = LABEL_INITIALIZED; |
0808925e EP |
891 | } |
892 | ||
c9180a57 | 893 | if (defcontext_sid) { |
eb9ae686 DQ |
894 | if (sbsec->behavior != SECURITY_FS_USE_XATTR && |
895 | sbsec->behavior != SECURITY_FS_USE_NATIVE) { | |
c9180a57 EP |
896 | rc = -EINVAL; |
897 | printk(KERN_WARNING "SELinux: defcontext option is " | |
898 | "invalid for this filesystem type\n"); | |
899 | goto out; | |
1da177e4 LT |
900 | } |
901 | ||
c9180a57 EP |
902 | if (defcontext_sid != sbsec->def_sid) { |
903 | rc = may_context_mount_inode_relabel(defcontext_sid, | |
275bb41e | 904 | sbsec, cred); |
c9180a57 EP |
905 | if (rc) |
906 | goto out; | |
907 | } | |
1da177e4 | 908 | |
c9180a57 | 909 | sbsec->def_sid = defcontext_sid; |
1da177e4 LT |
910 | } |
911 | ||
aad82892 | 912 | out_set_opts: |
c9180a57 | 913 | rc = sb_finish_set_opts(sb); |
1da177e4 | 914 | out: |
c9180a57 | 915 | mutex_unlock(&sbsec->lock); |
1da177e4 | 916 | return rc; |
c9180a57 EP |
917 | out_double_mount: |
918 | rc = -EINVAL; | |
919 | printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " | |
29b1deb2 | 920 | "security settings for (dev %s, type %s)\n", sb->s_id, name); |
c9180a57 | 921 | goto out; |
1da177e4 LT |
922 | } |
923 | ||
094f7b69 JL |
924 | static int selinux_cmp_sb_context(const struct super_block *oldsb, |
925 | const struct super_block *newsb) | |
926 | { | |
33132849 JS |
927 | struct superblock_security_struct *old = oldsb->s_security; |
928 | struct superblock_security_struct *new = newsb->s_security; | |
094f7b69 JL |
929 | char oldflags = old->flags & SE_MNTMASK; |
930 | char newflags = new->flags & SE_MNTMASK; | |
931 | ||
932 | if (oldflags != newflags) | |
933 | goto mismatch; | |
934 | if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid) | |
935 | goto mismatch; | |
936 | if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid) | |
937 | goto mismatch; | |
938 | if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid) | |
939 | goto mismatch; | |
940 | if (oldflags & ROOTCONTEXT_MNT) { | |
83da53c5 AG |
941 | struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root); |
942 | struct inode_security_struct *newroot = backing_inode_security(newsb->s_root); | |
094f7b69 JL |
943 | if (oldroot->sid != newroot->sid) |
944 | goto mismatch; | |
945 | } | |
946 | return 0; | |
947 | mismatch: | |
948 | printk(KERN_WARNING "SELinux: mount invalid. Same superblock, " | |
949 | "different security settings for (dev %s, " | |
950 | "type %s)\n", newsb->s_id, newsb->s_type->name); | |
951 | return -EBUSY; | |
952 | } | |
953 | ||
954 | static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, | |
0b4d3452 SM |
955 | struct super_block *newsb, |
956 | unsigned long kern_flags, | |
957 | unsigned long *set_kern_flags) | |
1da177e4 | 958 | { |
0b4d3452 | 959 | int rc = 0; |
33132849 JS |
960 | const struct superblock_security_struct *oldsbsec = oldsb->s_security; |
961 | struct superblock_security_struct *newsbsec = newsb->s_security; | |
1da177e4 | 962 | |
c9180a57 EP |
963 | int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); |
964 | int set_context = (oldsbsec->flags & CONTEXT_MNT); | |
965 | int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); | |
1da177e4 | 966 | |
0f5e6420 EP |
967 | /* |
968 | * if the parent was able to be mounted it clearly had no special lsm | |
e8c26255 | 969 | * mount options. thus we can safely deal with this superblock later |
0f5e6420 | 970 | */ |
e8c26255 | 971 | if (!ss_initialized) |
094f7b69 | 972 | return 0; |
c9180a57 | 973 | |
0b4d3452 SM |
974 | /* |
975 | * Specifying internal flags without providing a place to | |
976 | * place the results is not allowed. | |
977 | */ | |
978 | if (kern_flags && !set_kern_flags) | |
979 | return -EINVAL; | |
980 | ||
c9180a57 | 981 | /* how can we clone if the old one wasn't set up?? */ |
0d90a7ec | 982 | BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); |
c9180a57 | 983 | |
094f7b69 | 984 | /* if fs is reusing a sb, make sure that the contexts match */ |
0d90a7ec | 985 | if (newsbsec->flags & SE_SBINITIALIZED) |
094f7b69 | 986 | return selinux_cmp_sb_context(oldsb, newsb); |
5a552617 | 987 | |
c9180a57 EP |
988 | mutex_lock(&newsbsec->lock); |
989 | ||
990 | newsbsec->flags = oldsbsec->flags; | |
991 | ||
992 | newsbsec->sid = oldsbsec->sid; | |
993 | newsbsec->def_sid = oldsbsec->def_sid; | |
994 | newsbsec->behavior = oldsbsec->behavior; | |
995 | ||
0b4d3452 SM |
996 | if (newsbsec->behavior == SECURITY_FS_USE_NATIVE && |
997 | !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) { | |
998 | rc = security_fs_use(newsb); | |
999 | if (rc) | |
1000 | goto out; | |
1001 | } | |
1002 | ||
1003 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) { | |
1004 | newsbsec->behavior = SECURITY_FS_USE_NATIVE; | |
1005 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
1006 | } | |
1007 | ||
c9180a57 EP |
1008 | if (set_context) { |
1009 | u32 sid = oldsbsec->mntpoint_sid; | |
1010 | ||
1011 | if (!set_fscontext) | |
1012 | newsbsec->sid = sid; | |
1013 | if (!set_rootcontext) { | |
33132849 | 1014 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); |
c9180a57 EP |
1015 | newisec->sid = sid; |
1016 | } | |
1017 | newsbsec->mntpoint_sid = sid; | |
1da177e4 | 1018 | } |
c9180a57 | 1019 | if (set_rootcontext) { |
33132849 JS |
1020 | const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root); |
1021 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); | |
1da177e4 | 1022 | |
c9180a57 | 1023 | newisec->sid = oldisec->sid; |
1da177e4 LT |
1024 | } |
1025 | ||
c9180a57 | 1026 | sb_finish_set_opts(newsb); |
0b4d3452 | 1027 | out: |
c9180a57 | 1028 | mutex_unlock(&newsbsec->lock); |
0b4d3452 | 1029 | return rc; |
c9180a57 EP |
1030 | } |
1031 | ||
2e1479d9 AB |
1032 | static int selinux_parse_opts_str(char *options, |
1033 | struct security_mnt_opts *opts) | |
c9180a57 | 1034 | { |
e0007529 | 1035 | char *p; |
c9180a57 EP |
1036 | char *context = NULL, *defcontext = NULL; |
1037 | char *fscontext = NULL, *rootcontext = NULL; | |
e0007529 | 1038 | int rc, num_mnt_opts = 0; |
1da177e4 | 1039 | |
e0007529 | 1040 | opts->num_mnt_opts = 0; |
1da177e4 | 1041 | |
c9180a57 EP |
1042 | /* Standard string-based options. */ |
1043 | while ((p = strsep(&options, "|")) != NULL) { | |
1044 | int token; | |
1045 | substring_t args[MAX_OPT_ARGS]; | |
1da177e4 | 1046 | |
c9180a57 EP |
1047 | if (!*p) |
1048 | continue; | |
1da177e4 | 1049 | |
c9180a57 | 1050 | token = match_token(p, tokens, args); |
1da177e4 | 1051 | |
c9180a57 EP |
1052 | switch (token) { |
1053 | case Opt_context: | |
1054 | if (context || defcontext) { | |
1055 | rc = -EINVAL; | |
1056 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1057 | goto out_err; | |
1058 | } | |
1059 | context = match_strdup(&args[0]); | |
1060 | if (!context) { | |
1061 | rc = -ENOMEM; | |
1062 | goto out_err; | |
1063 | } | |
1064 | break; | |
1065 | ||
1066 | case Opt_fscontext: | |
1067 | if (fscontext) { | |
1068 | rc = -EINVAL; | |
1069 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1070 | goto out_err; | |
1071 | } | |
1072 | fscontext = match_strdup(&args[0]); | |
1073 | if (!fscontext) { | |
1074 | rc = -ENOMEM; | |
1075 | goto out_err; | |
1076 | } | |
1077 | break; | |
1078 | ||
1079 | case Opt_rootcontext: | |
1080 | if (rootcontext) { | |
1081 | rc = -EINVAL; | |
1082 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1083 | goto out_err; | |
1084 | } | |
1085 | rootcontext = match_strdup(&args[0]); | |
1086 | if (!rootcontext) { | |
1087 | rc = -ENOMEM; | |
1088 | goto out_err; | |
1089 | } | |
1090 | break; | |
1091 | ||
1092 | case Opt_defcontext: | |
1093 | if (context || defcontext) { | |
1094 | rc = -EINVAL; | |
1095 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1096 | goto out_err; | |
1097 | } | |
1098 | defcontext = match_strdup(&args[0]); | |
1099 | if (!defcontext) { | |
1100 | rc = -ENOMEM; | |
1101 | goto out_err; | |
1102 | } | |
1103 | break; | |
11689d47 DQ |
1104 | case Opt_labelsupport: |
1105 | break; | |
c9180a57 EP |
1106 | default: |
1107 | rc = -EINVAL; | |
1108 | printk(KERN_WARNING "SELinux: unknown mount option\n"); | |
1109 | goto out_err; | |
1da177e4 | 1110 | |
1da177e4 | 1111 | } |
1da177e4 | 1112 | } |
c9180a57 | 1113 | |
e0007529 | 1114 | rc = -ENOMEM; |
8931c3bd | 1115 | opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_KERNEL); |
e0007529 EP |
1116 | if (!opts->mnt_opts) |
1117 | goto out_err; | |
1118 | ||
8931c3bd TH |
1119 | opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), |
1120 | GFP_KERNEL); | |
023f108d | 1121 | if (!opts->mnt_opts_flags) |
e0007529 | 1122 | goto out_err; |
e0007529 | 1123 | |
c9180a57 | 1124 | if (fscontext) { |
e0007529 EP |
1125 | opts->mnt_opts[num_mnt_opts] = fscontext; |
1126 | opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; | |
c9180a57 EP |
1127 | } |
1128 | if (context) { | |
e0007529 EP |
1129 | opts->mnt_opts[num_mnt_opts] = context; |
1130 | opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; | |
c9180a57 EP |
1131 | } |
1132 | if (rootcontext) { | |
e0007529 EP |
1133 | opts->mnt_opts[num_mnt_opts] = rootcontext; |
1134 | opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; | |
c9180a57 EP |
1135 | } |
1136 | if (defcontext) { | |
e0007529 EP |
1137 | opts->mnt_opts[num_mnt_opts] = defcontext; |
1138 | opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; | |
c9180a57 EP |
1139 | } |
1140 | ||
e0007529 EP |
1141 | opts->num_mnt_opts = num_mnt_opts; |
1142 | return 0; | |
1143 | ||
c9180a57 | 1144 | out_err: |
023f108d | 1145 | security_free_mnt_opts(opts); |
c9180a57 EP |
1146 | kfree(context); |
1147 | kfree(defcontext); | |
1148 | kfree(fscontext); | |
1149 | kfree(rootcontext); | |
1da177e4 LT |
1150 | return rc; |
1151 | } | |
e0007529 EP |
1152 | /* |
1153 | * string mount options parsing and call set the sbsec | |
1154 | */ | |
1155 | static int superblock_doinit(struct super_block *sb, void *data) | |
1156 | { | |
1157 | int rc = 0; | |
1158 | char *options = data; | |
1159 | struct security_mnt_opts opts; | |
1160 | ||
1161 | security_init_mnt_opts(&opts); | |
1162 | ||
1163 | if (!data) | |
1164 | goto out; | |
1165 | ||
1166 | BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); | |
1167 | ||
1168 | rc = selinux_parse_opts_str(options, &opts); | |
1169 | if (rc) | |
1170 | goto out_err; | |
1171 | ||
1172 | out: | |
649f6e77 | 1173 | rc = selinux_set_mnt_opts(sb, &opts, 0, NULL); |
e0007529 EP |
1174 | |
1175 | out_err: | |
1176 | security_free_mnt_opts(&opts); | |
1177 | return rc; | |
1178 | } | |
1da177e4 | 1179 | |
3583a711 AB |
1180 | static void selinux_write_opts(struct seq_file *m, |
1181 | struct security_mnt_opts *opts) | |
2069f457 EP |
1182 | { |
1183 | int i; | |
1184 | char *prefix; | |
1185 | ||
1186 | for (i = 0; i < opts->num_mnt_opts; i++) { | |
11689d47 DQ |
1187 | char *has_comma; |
1188 | ||
1189 | if (opts->mnt_opts[i]) | |
1190 | has_comma = strchr(opts->mnt_opts[i], ','); | |
1191 | else | |
1192 | has_comma = NULL; | |
2069f457 EP |
1193 | |
1194 | switch (opts->mnt_opts_flags[i]) { | |
1195 | case CONTEXT_MNT: | |
1196 | prefix = CONTEXT_STR; | |
1197 | break; | |
1198 | case FSCONTEXT_MNT: | |
1199 | prefix = FSCONTEXT_STR; | |
1200 | break; | |
1201 | case ROOTCONTEXT_MNT: | |
1202 | prefix = ROOTCONTEXT_STR; | |
1203 | break; | |
1204 | case DEFCONTEXT_MNT: | |
1205 | prefix = DEFCONTEXT_STR; | |
1206 | break; | |
12f348b9 | 1207 | case SBLABEL_MNT: |
11689d47 DQ |
1208 | seq_putc(m, ','); |
1209 | seq_puts(m, LABELSUPP_STR); | |
1210 | continue; | |
2069f457 EP |
1211 | default: |
1212 | BUG(); | |
a35c6c83 | 1213 | return; |
2069f457 EP |
1214 | }; |
1215 | /* we need a comma before each option */ | |
1216 | seq_putc(m, ','); | |
1217 | seq_puts(m, prefix); | |
1218 | if (has_comma) | |
1219 | seq_putc(m, '\"'); | |
a068acf2 | 1220 | seq_escape(m, opts->mnt_opts[i], "\"\n\\"); |
2069f457 EP |
1221 | if (has_comma) |
1222 | seq_putc(m, '\"'); | |
1223 | } | |
1224 | } | |
1225 | ||
1226 | static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) | |
1227 | { | |
1228 | struct security_mnt_opts opts; | |
1229 | int rc; | |
1230 | ||
1231 | rc = selinux_get_mnt_opts(sb, &opts); | |
383795c2 EP |
1232 | if (rc) { |
1233 | /* before policy load we may get EINVAL, don't show anything */ | |
1234 | if (rc == -EINVAL) | |
1235 | rc = 0; | |
2069f457 | 1236 | return rc; |
383795c2 | 1237 | } |
2069f457 EP |
1238 | |
1239 | selinux_write_opts(m, &opts); | |
1240 | ||
1241 | security_free_mnt_opts(&opts); | |
1242 | ||
1243 | return rc; | |
1244 | } | |
1245 | ||
1da177e4 LT |
1246 | static inline u16 inode_mode_to_security_class(umode_t mode) |
1247 | { | |
1248 | switch (mode & S_IFMT) { | |
1249 | case S_IFSOCK: | |
1250 | return SECCLASS_SOCK_FILE; | |
1251 | case S_IFLNK: | |
1252 | return SECCLASS_LNK_FILE; | |
1253 | case S_IFREG: | |
1254 | return SECCLASS_FILE; | |
1255 | case S_IFBLK: | |
1256 | return SECCLASS_BLK_FILE; | |
1257 | case S_IFDIR: | |
1258 | return SECCLASS_DIR; | |
1259 | case S_IFCHR: | |
1260 | return SECCLASS_CHR_FILE; | |
1261 | case S_IFIFO: | |
1262 | return SECCLASS_FIFO_FILE; | |
1263 | ||
1264 | } | |
1265 | ||
1266 | return SECCLASS_FILE; | |
1267 | } | |
1268 | ||
13402580 JM |
1269 | static inline int default_protocol_stream(int protocol) |
1270 | { | |
1271 | return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); | |
1272 | } | |
1273 | ||
1274 | static inline int default_protocol_dgram(int protocol) | |
1275 | { | |
1276 | return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); | |
1277 | } | |
1278 | ||
1da177e4 LT |
1279 | static inline u16 socket_type_to_security_class(int family, int type, int protocol) |
1280 | { | |
da69a530 SS |
1281 | int extsockclass = selinux_policycap_extsockclass; |
1282 | ||
1da177e4 LT |
1283 | switch (family) { |
1284 | case PF_UNIX: | |
1285 | switch (type) { | |
1286 | case SOCK_STREAM: | |
1287 | case SOCK_SEQPACKET: | |
1288 | return SECCLASS_UNIX_STREAM_SOCKET; | |
1289 | case SOCK_DGRAM: | |
1290 | return SECCLASS_UNIX_DGRAM_SOCKET; | |
1291 | } | |
1292 | break; | |
1293 | case PF_INET: | |
1294 | case PF_INET6: | |
1295 | switch (type) { | |
1296 | case SOCK_STREAM: | |
da69a530 | 1297 | case SOCK_SEQPACKET: |
13402580 JM |
1298 | if (default_protocol_stream(protocol)) |
1299 | return SECCLASS_TCP_SOCKET; | |
da69a530 SS |
1300 | else if (extsockclass && protocol == IPPROTO_SCTP) |
1301 | return SECCLASS_SCTP_SOCKET; | |
13402580 JM |
1302 | else |
1303 | return SECCLASS_RAWIP_SOCKET; | |
1da177e4 | 1304 | case SOCK_DGRAM: |
13402580 JM |
1305 | if (default_protocol_dgram(protocol)) |
1306 | return SECCLASS_UDP_SOCKET; | |
ef37979a SS |
1307 | else if (extsockclass && (protocol == IPPROTO_ICMP || |
1308 | protocol == IPPROTO_ICMPV6)) | |
da69a530 | 1309 | return SECCLASS_ICMP_SOCKET; |
13402580 JM |
1310 | else |
1311 | return SECCLASS_RAWIP_SOCKET; | |
2ee92d46 JM |
1312 | case SOCK_DCCP: |
1313 | return SECCLASS_DCCP_SOCKET; | |
13402580 | 1314 | default: |
1da177e4 LT |
1315 | return SECCLASS_RAWIP_SOCKET; |
1316 | } | |
1317 | break; | |
1318 | case PF_NETLINK: | |
1319 | switch (protocol) { | |
1320 | case NETLINK_ROUTE: | |
1321 | return SECCLASS_NETLINK_ROUTE_SOCKET; | |
7f1fb60c | 1322 | case NETLINK_SOCK_DIAG: |
1da177e4 LT |
1323 | return SECCLASS_NETLINK_TCPDIAG_SOCKET; |
1324 | case NETLINK_NFLOG: | |
1325 | return SECCLASS_NETLINK_NFLOG_SOCKET; | |
1326 | case NETLINK_XFRM: | |
1327 | return SECCLASS_NETLINK_XFRM_SOCKET; | |
1328 | case NETLINK_SELINUX: | |
1329 | return SECCLASS_NETLINK_SELINUX_SOCKET; | |
6c6d2e9b SS |
1330 | case NETLINK_ISCSI: |
1331 | return SECCLASS_NETLINK_ISCSI_SOCKET; | |
1da177e4 LT |
1332 | case NETLINK_AUDIT: |
1333 | return SECCLASS_NETLINK_AUDIT_SOCKET; | |
6c6d2e9b SS |
1334 | case NETLINK_FIB_LOOKUP: |
1335 | return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET; | |
1336 | case NETLINK_CONNECTOR: | |
1337 | return SECCLASS_NETLINK_CONNECTOR_SOCKET; | |
1338 | case NETLINK_NETFILTER: | |
1339 | return SECCLASS_NETLINK_NETFILTER_SOCKET; | |
1da177e4 LT |
1340 | case NETLINK_DNRTMSG: |
1341 | return SECCLASS_NETLINK_DNRT_SOCKET; | |
0c9b7942 JM |
1342 | case NETLINK_KOBJECT_UEVENT: |
1343 | return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; | |
6c6d2e9b SS |
1344 | case NETLINK_GENERIC: |
1345 | return SECCLASS_NETLINK_GENERIC_SOCKET; | |
1346 | case NETLINK_SCSITRANSPORT: | |
1347 | return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET; | |
1348 | case NETLINK_RDMA: | |
1349 | return SECCLASS_NETLINK_RDMA_SOCKET; | |
1350 | case NETLINK_CRYPTO: | |
1351 | return SECCLASS_NETLINK_CRYPTO_SOCKET; | |
1da177e4 LT |
1352 | default: |
1353 | return SECCLASS_NETLINK_SOCKET; | |
1354 | } | |
1355 | case PF_PACKET: | |
1356 | return SECCLASS_PACKET_SOCKET; | |
1357 | case PF_KEY: | |
1358 | return SECCLASS_KEY_SOCKET; | |
3e3ff15e CP |
1359 | case PF_APPLETALK: |
1360 | return SECCLASS_APPLETALK_SOCKET; | |
1da177e4 LT |
1361 | } |
1362 | ||
da69a530 SS |
1363 | if (extsockclass) { |
1364 | switch (family) { | |
1365 | case PF_AX25: | |
1366 | return SECCLASS_AX25_SOCKET; | |
1367 | case PF_IPX: | |
1368 | return SECCLASS_IPX_SOCKET; | |
1369 | case PF_NETROM: | |
1370 | return SECCLASS_NETROM_SOCKET; | |
da69a530 SS |
1371 | case PF_ATMPVC: |
1372 | return SECCLASS_ATMPVC_SOCKET; | |
1373 | case PF_X25: | |
1374 | return SECCLASS_X25_SOCKET; | |
1375 | case PF_ROSE: | |
1376 | return SECCLASS_ROSE_SOCKET; | |
1377 | case PF_DECnet: | |
1378 | return SECCLASS_DECNET_SOCKET; | |
1379 | case PF_ATMSVC: | |
1380 | return SECCLASS_ATMSVC_SOCKET; | |
1381 | case PF_RDS: | |
1382 | return SECCLASS_RDS_SOCKET; | |
1383 | case PF_IRDA: | |
1384 | return SECCLASS_IRDA_SOCKET; | |
1385 | case PF_PPPOX: | |
1386 | return SECCLASS_PPPOX_SOCKET; | |
1387 | case PF_LLC: | |
1388 | return SECCLASS_LLC_SOCKET; | |
da69a530 SS |
1389 | case PF_CAN: |
1390 | return SECCLASS_CAN_SOCKET; | |
1391 | case PF_TIPC: | |
1392 | return SECCLASS_TIPC_SOCKET; | |
1393 | case PF_BLUETOOTH: | |
1394 | return SECCLASS_BLUETOOTH_SOCKET; | |
1395 | case PF_IUCV: | |
1396 | return SECCLASS_IUCV_SOCKET; | |
1397 | case PF_RXRPC: | |
1398 | return SECCLASS_RXRPC_SOCKET; | |
1399 | case PF_ISDN: | |
1400 | return SECCLASS_ISDN_SOCKET; | |
1401 | case PF_PHONET: | |
1402 | return SECCLASS_PHONET_SOCKET; | |
1403 | case PF_IEEE802154: | |
1404 | return SECCLASS_IEEE802154_SOCKET; | |
1405 | case PF_CAIF: | |
1406 | return SECCLASS_CAIF_SOCKET; | |
1407 | case PF_ALG: | |
1408 | return SECCLASS_ALG_SOCKET; | |
1409 | case PF_NFC: | |
1410 | return SECCLASS_NFC_SOCKET; | |
1411 | case PF_VSOCK: | |
1412 | return SECCLASS_VSOCK_SOCKET; | |
1413 | case PF_KCM: | |
1414 | return SECCLASS_KCM_SOCKET; | |
1415 | case PF_QIPCRTR: | |
1416 | return SECCLASS_QIPCRTR_SOCKET; | |
3051bf36 LT |
1417 | case PF_SMC: |
1418 | return SECCLASS_SMC_SOCKET; | |
1419 | #if PF_MAX > 44 | |
da69a530 SS |
1420 | #error New address family defined, please update this function. |
1421 | #endif | |
1422 | } | |
1423 | } | |
1424 | ||
1da177e4 LT |
1425 | return SECCLASS_SOCKET; |
1426 | } | |
1427 | ||
134509d5 SS |
1428 | static int selinux_genfs_get_sid(struct dentry *dentry, |
1429 | u16 tclass, | |
1430 | u16 flags, | |
1431 | u32 *sid) | |
1da177e4 | 1432 | { |
8e6c9693 | 1433 | int rc; |
fc64005c | 1434 | struct super_block *sb = dentry->d_sb; |
8e6c9693 | 1435 | char *buffer, *path; |
1da177e4 | 1436 | |
828dfe1d | 1437 | buffer = (char *)__get_free_page(GFP_KERNEL); |
1da177e4 LT |
1438 | if (!buffer) |
1439 | return -ENOMEM; | |
1440 | ||
8e6c9693 LAG |
1441 | path = dentry_path_raw(dentry, buffer, PAGE_SIZE); |
1442 | if (IS_ERR(path)) | |
1443 | rc = PTR_ERR(path); | |
1444 | else { | |
134509d5 SS |
1445 | if (flags & SE_SBPROC) { |
1446 | /* each process gets a /proc/PID/ entry. Strip off the | |
1447 | * PID part to get a valid selinux labeling. | |
1448 | * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ | |
1449 | while (path[1] >= '0' && path[1] <= '9') { | |
1450 | path[1] = '/'; | |
1451 | path++; | |
1452 | } | |
8e6c9693 | 1453 | } |
134509d5 | 1454 | rc = security_genfs_sid(sb->s_type->name, path, tclass, sid); |
1da177e4 | 1455 | } |
1da177e4 LT |
1456 | free_page((unsigned long)buffer); |
1457 | return rc; | |
1458 | } | |
1da177e4 LT |
1459 | |
1460 | /* The inode's security attributes must be initialized before first use. */ | |
1461 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) | |
1462 | { | |
1463 | struct superblock_security_struct *sbsec = NULL; | |
33132849 | 1464 | struct inode_security_struct *isec = inode->i_security; |
9287aed2 AG |
1465 | u32 task_sid, sid = 0; |
1466 | u16 sclass; | |
1da177e4 LT |
1467 | struct dentry *dentry; |
1468 | #define INITCONTEXTLEN 255 | |
1469 | char *context = NULL; | |
1470 | unsigned len = 0; | |
1471 | int rc = 0; | |
1da177e4 | 1472 | |
6f3be9f5 | 1473 | if (isec->initialized == LABEL_INITIALIZED) |
13457d07 | 1474 | return 0; |
1da177e4 | 1475 | |
9287aed2 | 1476 | spin_lock(&isec->lock); |
6f3be9f5 | 1477 | if (isec->initialized == LABEL_INITIALIZED) |
23970741 | 1478 | goto out_unlock; |
1da177e4 | 1479 | |
13457d07 AG |
1480 | if (isec->sclass == SECCLASS_FILE) |
1481 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
1482 | ||
33132849 | 1483 | sbsec = inode->i_sb->s_security; |
0d90a7ec | 1484 | if (!(sbsec->flags & SE_SBINITIALIZED)) { |
1da177e4 LT |
1485 | /* Defer initialization until selinux_complete_init, |
1486 | after the initial policy is loaded and the security | |
1487 | server is ready to handle calls. */ | |
1488 | spin_lock(&sbsec->isec_lock); | |
1489 | if (list_empty(&isec->list)) | |
1490 | list_add(&isec->list, &sbsec->isec_head); | |
1491 | spin_unlock(&sbsec->isec_lock); | |
23970741 | 1492 | goto out_unlock; |
1da177e4 LT |
1493 | } |
1494 | ||
9287aed2 AG |
1495 | sclass = isec->sclass; |
1496 | task_sid = isec->task_sid; | |
1497 | sid = isec->sid; | |
1498 | isec->initialized = LABEL_PENDING; | |
1499 | spin_unlock(&isec->lock); | |
1500 | ||
1da177e4 | 1501 | switch (sbsec->behavior) { |
eb9ae686 DQ |
1502 | case SECURITY_FS_USE_NATIVE: |
1503 | break; | |
1da177e4 | 1504 | case SECURITY_FS_USE_XATTR: |
5d6c3191 | 1505 | if (!(inode->i_opflags & IOP_XATTR)) { |
9287aed2 | 1506 | sid = sbsec->def_sid; |
1da177e4 LT |
1507 | break; |
1508 | } | |
1da177e4 LT |
1509 | /* Need a dentry, since the xattr API requires one. |
1510 | Life would be simpler if we could just pass the inode. */ | |
1511 | if (opt_dentry) { | |
1512 | /* Called from d_instantiate or d_splice_alias. */ | |
1513 | dentry = dget(opt_dentry); | |
1514 | } else { | |
1515 | /* Called from selinux_complete_init, try to find a dentry. */ | |
1516 | dentry = d_find_alias(inode); | |
1517 | } | |
1518 | if (!dentry) { | |
df7f54c0 EP |
1519 | /* |
1520 | * this is can be hit on boot when a file is accessed | |
1521 | * before the policy is loaded. When we load policy we | |
1522 | * may find inodes that have no dentry on the | |
1523 | * sbsec->isec_head list. No reason to complain as these | |
1524 | * will get fixed up the next time we go through | |
1525 | * inode_doinit with a dentry, before these inodes could | |
1526 | * be used again by userspace. | |
1527 | */ | |
9287aed2 | 1528 | goto out; |
1da177e4 LT |
1529 | } |
1530 | ||
1531 | len = INITCONTEXTLEN; | |
4cb912f1 | 1532 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1533 | if (!context) { |
1534 | rc = -ENOMEM; | |
1535 | dput(dentry); | |
9287aed2 | 1536 | goto out; |
1da177e4 | 1537 | } |
4cb912f1 | 1538 | context[len] = '\0'; |
5d6c3191 | 1539 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 | 1540 | if (rc == -ERANGE) { |
314dabb8 JM |
1541 | kfree(context); |
1542 | ||
1da177e4 | 1543 | /* Need a larger buffer. Query for the right size. */ |
5d6c3191 | 1544 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0); |
1da177e4 LT |
1545 | if (rc < 0) { |
1546 | dput(dentry); | |
9287aed2 | 1547 | goto out; |
1da177e4 | 1548 | } |
1da177e4 | 1549 | len = rc; |
4cb912f1 | 1550 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1551 | if (!context) { |
1552 | rc = -ENOMEM; | |
1553 | dput(dentry); | |
9287aed2 | 1554 | goto out; |
1da177e4 | 1555 | } |
4cb912f1 | 1556 | context[len] = '\0'; |
5d6c3191 | 1557 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 LT |
1558 | } |
1559 | dput(dentry); | |
1560 | if (rc < 0) { | |
1561 | if (rc != -ENODATA) { | |
744ba35e | 1562 | printk(KERN_WARNING "SELinux: %s: getxattr returned " |
dd6f953a | 1563 | "%d for dev=%s ino=%ld\n", __func__, |
1da177e4 LT |
1564 | -rc, inode->i_sb->s_id, inode->i_ino); |
1565 | kfree(context); | |
9287aed2 | 1566 | goto out; |
1da177e4 LT |
1567 | } |
1568 | /* Map ENODATA to the default file SID */ | |
1569 | sid = sbsec->def_sid; | |
1570 | rc = 0; | |
1571 | } else { | |
f5c1d5b2 | 1572 | rc = security_context_to_sid_default(context, rc, &sid, |
869ab514 SS |
1573 | sbsec->def_sid, |
1574 | GFP_NOFS); | |
1da177e4 | 1575 | if (rc) { |
4ba0a8ad EP |
1576 | char *dev = inode->i_sb->s_id; |
1577 | unsigned long ino = inode->i_ino; | |
1578 | ||
1579 | if (rc == -EINVAL) { | |
1580 | if (printk_ratelimit()) | |
1581 | printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " | |
1582 | "context=%s. This indicates you may need to relabel the inode or the " | |
1583 | "filesystem in question.\n", ino, dev, context); | |
1584 | } else { | |
1585 | printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " | |
1586 | "returned %d for dev=%s ino=%ld\n", | |
1587 | __func__, context, -rc, dev, ino); | |
1588 | } | |
1da177e4 LT |
1589 | kfree(context); |
1590 | /* Leave with the unlabeled SID */ | |
1591 | rc = 0; | |
1592 | break; | |
1593 | } | |
1594 | } | |
1595 | kfree(context); | |
1da177e4 LT |
1596 | break; |
1597 | case SECURITY_FS_USE_TASK: | |
9287aed2 | 1598 | sid = task_sid; |
1da177e4 LT |
1599 | break; |
1600 | case SECURITY_FS_USE_TRANS: | |
1601 | /* Default to the fs SID. */ | |
9287aed2 | 1602 | sid = sbsec->sid; |
1da177e4 LT |
1603 | |
1604 | /* Try to obtain a transition SID. */ | |
9287aed2 | 1605 | rc = security_transition_sid(task_sid, sid, sclass, NULL, &sid); |
1da177e4 | 1606 | if (rc) |
9287aed2 | 1607 | goto out; |
1da177e4 | 1608 | break; |
c312feb2 | 1609 | case SECURITY_FS_USE_MNTPOINT: |
9287aed2 | 1610 | sid = sbsec->mntpoint_sid; |
c312feb2 | 1611 | break; |
1da177e4 | 1612 | default: |
c312feb2 | 1613 | /* Default to the fs superblock SID. */ |
9287aed2 | 1614 | sid = sbsec->sid; |
1da177e4 | 1615 | |
134509d5 | 1616 | if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) { |
f64410ec PM |
1617 | /* We must have a dentry to determine the label on |
1618 | * procfs inodes */ | |
1619 | if (opt_dentry) | |
1620 | /* Called from d_instantiate or | |
1621 | * d_splice_alias. */ | |
1622 | dentry = dget(opt_dentry); | |
1623 | else | |
1624 | /* Called from selinux_complete_init, try to | |
1625 | * find a dentry. */ | |
1626 | dentry = d_find_alias(inode); | |
1627 | /* | |
1628 | * This can be hit on boot when a file is accessed | |
1629 | * before the policy is loaded. When we load policy we | |
1630 | * may find inodes that have no dentry on the | |
1631 | * sbsec->isec_head list. No reason to complain as | |
1632 | * these will get fixed up the next time we go through | |
1633 | * inode_doinit() with a dentry, before these inodes | |
1634 | * could be used again by userspace. | |
1635 | */ | |
1636 | if (!dentry) | |
9287aed2 AG |
1637 | goto out; |
1638 | rc = selinux_genfs_get_sid(dentry, sclass, | |
134509d5 | 1639 | sbsec->flags, &sid); |
f64410ec PM |
1640 | dput(dentry); |
1641 | if (rc) | |
9287aed2 | 1642 | goto out; |
1da177e4 LT |
1643 | } |
1644 | break; | |
1645 | } | |
1646 | ||
9287aed2 AG |
1647 | out: |
1648 | spin_lock(&isec->lock); | |
1649 | if (isec->initialized == LABEL_PENDING) { | |
1650 | if (!sid || rc) { | |
1651 | isec->initialized = LABEL_INVALID; | |
1652 | goto out_unlock; | |
1653 | } | |
1654 | ||
1655 | isec->initialized = LABEL_INITIALIZED; | |
1656 | isec->sid = sid; | |
1657 | } | |
1da177e4 | 1658 | |
23970741 | 1659 | out_unlock: |
9287aed2 | 1660 | spin_unlock(&isec->lock); |
1da177e4 LT |
1661 | return rc; |
1662 | } | |
1663 | ||
1664 | /* Convert a Linux signal to an access vector. */ | |
1665 | static inline u32 signal_to_av(int sig) | |
1666 | { | |
1667 | u32 perm = 0; | |
1668 | ||
1669 | switch (sig) { | |
1670 | case SIGCHLD: | |
1671 | /* Commonly granted from child to parent. */ | |
1672 | perm = PROCESS__SIGCHLD; | |
1673 | break; | |
1674 | case SIGKILL: | |
1675 | /* Cannot be caught or ignored */ | |
1676 | perm = PROCESS__SIGKILL; | |
1677 | break; | |
1678 | case SIGSTOP: | |
1679 | /* Cannot be caught or ignored */ | |
1680 | perm = PROCESS__SIGSTOP; | |
1681 | break; | |
1682 | default: | |
1683 | /* All other signals. */ | |
1684 | perm = PROCESS__SIGNAL; | |
1685 | break; | |
1686 | } | |
1687 | ||
1688 | return perm; | |
1689 | } | |
1690 | ||
b68e418c SS |
1691 | #if CAP_LAST_CAP > 63 |
1692 | #error Fix SELinux to handle capabilities > 63. | |
1693 | #endif | |
1694 | ||
1da177e4 | 1695 | /* Check whether a task is allowed to use a capability. */ |
6a9de491 | 1696 | static int cred_has_capability(const struct cred *cred, |
8e4ff6f2 | 1697 | int cap, int audit, bool initns) |
1da177e4 | 1698 | { |
2bf49690 | 1699 | struct common_audit_data ad; |
06112163 | 1700 | struct av_decision avd; |
b68e418c | 1701 | u16 sclass; |
3699c53c | 1702 | u32 sid = cred_sid(cred); |
b68e418c | 1703 | u32 av = CAP_TO_MASK(cap); |
06112163 | 1704 | int rc; |
1da177e4 | 1705 | |
50c205f5 | 1706 | ad.type = LSM_AUDIT_DATA_CAP; |
1da177e4 LT |
1707 | ad.u.cap = cap; |
1708 | ||
b68e418c SS |
1709 | switch (CAP_TO_INDEX(cap)) { |
1710 | case 0: | |
8e4ff6f2 | 1711 | sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS; |
b68e418c SS |
1712 | break; |
1713 | case 1: | |
8e4ff6f2 | 1714 | sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS; |
b68e418c SS |
1715 | break; |
1716 | default: | |
1717 | printk(KERN_ERR | |
1718 | "SELinux: out of range capability %d\n", cap); | |
1719 | BUG(); | |
a35c6c83 | 1720 | return -EINVAL; |
b68e418c | 1721 | } |
06112163 | 1722 | |
275bb41e | 1723 | rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); |
9ade0cf4 | 1724 | if (audit == SECURITY_CAP_AUDIT) { |
7b20ea25 | 1725 | int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0); |
9ade0cf4 EP |
1726 | if (rc2) |
1727 | return rc2; | |
1728 | } | |
06112163 | 1729 | return rc; |
1da177e4 LT |
1730 | } |
1731 | ||
1da177e4 LT |
1732 | /* Check whether a task has a particular permission to an inode. |
1733 | The 'adp' parameter is optional and allows other audit | |
1734 | data to be passed (e.g. the dentry). */ | |
88e67f3b | 1735 | static int inode_has_perm(const struct cred *cred, |
1da177e4 LT |
1736 | struct inode *inode, |
1737 | u32 perms, | |
19e49834 | 1738 | struct common_audit_data *adp) |
1da177e4 | 1739 | { |
1da177e4 | 1740 | struct inode_security_struct *isec; |
275bb41e | 1741 | u32 sid; |
1da177e4 | 1742 | |
e0e81739 DH |
1743 | validate_creds(cred); |
1744 | ||
828dfe1d | 1745 | if (unlikely(IS_PRIVATE(inode))) |
bbaca6c2 SS |
1746 | return 0; |
1747 | ||
88e67f3b | 1748 | sid = cred_sid(cred); |
33132849 | 1749 | isec = inode->i_security; |
1da177e4 | 1750 | |
19e49834 | 1751 | return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp); |
1da177e4 LT |
1752 | } |
1753 | ||
1754 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1755 | the dentry to help the auditing code to more easily generate the | |
1756 | pathname if needed. */ | |
88e67f3b | 1757 | static inline int dentry_has_perm(const struct cred *cred, |
1da177e4 LT |
1758 | struct dentry *dentry, |
1759 | u32 av) | |
1760 | { | |
c6f493d6 | 1761 | struct inode *inode = d_backing_inode(dentry); |
2bf49690 | 1762 | struct common_audit_data ad; |
88e67f3b | 1763 | |
50c205f5 | 1764 | ad.type = LSM_AUDIT_DATA_DENTRY; |
2875fa00 | 1765 | ad.u.dentry = dentry; |
5d226df4 | 1766 | __inode_security_revalidate(inode, dentry, true); |
19e49834 | 1767 | return inode_has_perm(cred, inode, av, &ad); |
2875fa00 EP |
1768 | } |
1769 | ||
1770 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1771 | the path to help the auditing code to more easily generate the | |
1772 | pathname if needed. */ | |
1773 | static inline int path_has_perm(const struct cred *cred, | |
3f7036a0 | 1774 | const struct path *path, |
2875fa00 EP |
1775 | u32 av) |
1776 | { | |
c6f493d6 | 1777 | struct inode *inode = d_backing_inode(path->dentry); |
2875fa00 EP |
1778 | struct common_audit_data ad; |
1779 | ||
50c205f5 | 1780 | ad.type = LSM_AUDIT_DATA_PATH; |
2875fa00 | 1781 | ad.u.path = *path; |
5d226df4 | 1782 | __inode_security_revalidate(inode, path->dentry, true); |
19e49834 | 1783 | return inode_has_perm(cred, inode, av, &ad); |
1da177e4 LT |
1784 | } |
1785 | ||
13f8e981 DH |
1786 | /* Same as path_has_perm, but uses the inode from the file struct. */ |
1787 | static inline int file_path_has_perm(const struct cred *cred, | |
1788 | struct file *file, | |
1789 | u32 av) | |
1790 | { | |
1791 | struct common_audit_data ad; | |
1792 | ||
43af5de7 VG |
1793 | ad.type = LSM_AUDIT_DATA_FILE; |
1794 | ad.u.file = file; | |
19e49834 | 1795 | return inode_has_perm(cred, file_inode(file), av, &ad); |
13f8e981 DH |
1796 | } |
1797 | ||
1da177e4 LT |
1798 | /* Check whether a task can use an open file descriptor to |
1799 | access an inode in a given way. Check access to the | |
1800 | descriptor itself, and then use dentry_has_perm to | |
1801 | check a particular permission to the file. | |
1802 | Access to the descriptor is implicitly granted if it | |
1803 | has the same SID as the process. If av is zero, then | |
1804 | access to the file is not checked, e.g. for cases | |
1805 | where only the descriptor is affected like seek. */ | |
88e67f3b DH |
1806 | static int file_has_perm(const struct cred *cred, |
1807 | struct file *file, | |
1808 | u32 av) | |
1da177e4 | 1809 | { |
004c5200 | 1810 | struct file_security_struct *fsec = selinux_file(file); |
496ad9aa | 1811 | struct inode *inode = file_inode(file); |
2bf49690 | 1812 | struct common_audit_data ad; |
88e67f3b | 1813 | u32 sid = cred_sid(cred); |
1da177e4 LT |
1814 | int rc; |
1815 | ||
43af5de7 VG |
1816 | ad.type = LSM_AUDIT_DATA_FILE; |
1817 | ad.u.file = file; | |
1da177e4 | 1818 | |
275bb41e DH |
1819 | if (sid != fsec->sid) { |
1820 | rc = avc_has_perm(sid, fsec->sid, | |
1da177e4 LT |
1821 | SECCLASS_FD, |
1822 | FD__USE, | |
1823 | &ad); | |
1824 | if (rc) | |
88e67f3b | 1825 | goto out; |
1da177e4 LT |
1826 | } |
1827 | ||
1828 | /* av is zero if only checking access to the descriptor. */ | |
88e67f3b | 1829 | rc = 0; |
1da177e4 | 1830 | if (av) |
19e49834 | 1831 | rc = inode_has_perm(cred, inode, av, &ad); |
1da177e4 | 1832 | |
88e67f3b DH |
1833 | out: |
1834 | return rc; | |
1da177e4 LT |
1835 | } |
1836 | ||
c3c188b2 DH |
1837 | /* |
1838 | * Determine the label for an inode that might be unioned. | |
1839 | */ | |
c957f6df VG |
1840 | static int |
1841 | selinux_determine_inode_label(const struct task_security_struct *tsec, | |
1842 | struct inode *dir, | |
1843 | const struct qstr *name, u16 tclass, | |
1844 | u32 *_new_isid) | |
c3c188b2 | 1845 | { |
33132849 | 1846 | const struct superblock_security_struct *sbsec = dir->i_sb->s_security; |
c3c188b2 DH |
1847 | |
1848 | if ((sbsec->flags & SE_SBINITIALIZED) && | |
1849 | (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { | |
1850 | *_new_isid = sbsec->mntpoint_sid; | |
1851 | } else if ((sbsec->flags & SBLABEL_MNT) && | |
1852 | tsec->create_sid) { | |
1853 | *_new_isid = tsec->create_sid; | |
1854 | } else { | |
20cdef8d | 1855 | const struct inode_security_struct *dsec = inode_security(dir); |
c3c188b2 DH |
1856 | return security_transition_sid(tsec->sid, dsec->sid, tclass, |
1857 | name, _new_isid); | |
1858 | } | |
1859 | ||
1860 | return 0; | |
1861 | } | |
1862 | ||
1da177e4 LT |
1863 | /* Check whether a task can create a file. */ |
1864 | static int may_create(struct inode *dir, | |
1865 | struct dentry *dentry, | |
1866 | u16 tclass) | |
1867 | { | |
98738d70 | 1868 | const struct task_security_struct *tsec = selinux_cred(current_cred()); |
1da177e4 LT |
1869 | struct inode_security_struct *dsec; |
1870 | struct superblock_security_struct *sbsec; | |
275bb41e | 1871 | u32 sid, newsid; |
2bf49690 | 1872 | struct common_audit_data ad; |
1da177e4 LT |
1873 | int rc; |
1874 | ||
83da53c5 | 1875 | dsec = inode_security(dir); |
33132849 | 1876 | sbsec = dir->i_sb->s_security; |
1da177e4 | 1877 | |
275bb41e | 1878 | sid = tsec->sid; |
275bb41e | 1879 | |
50c205f5 | 1880 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1881 | ad.u.dentry = dentry; |
1da177e4 | 1882 | |
275bb41e | 1883 | rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, |
1da177e4 LT |
1884 | DIR__ADD_NAME | DIR__SEARCH, |
1885 | &ad); | |
1886 | if (rc) | |
1887 | return rc; | |
1888 | ||
98738d70 | 1889 | rc = selinux_determine_inode_label(selinux_cred(current_cred()), dir, |
c957f6df | 1890 | &dentry->d_name, tclass, &newsid); |
c3c188b2 DH |
1891 | if (rc) |
1892 | return rc; | |
1da177e4 | 1893 | |
275bb41e | 1894 | rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); |
1da177e4 LT |
1895 | if (rc) |
1896 | return rc; | |
1897 | ||
1898 | return avc_has_perm(newsid, sbsec->sid, | |
1899 | SECCLASS_FILESYSTEM, | |
1900 | FILESYSTEM__ASSOCIATE, &ad); | |
1901 | } | |
1902 | ||
828dfe1d EP |
1903 | #define MAY_LINK 0 |
1904 | #define MAY_UNLINK 1 | |
1905 | #define MAY_RMDIR 2 | |
1da177e4 LT |
1906 | |
1907 | /* Check whether a task can link, unlink, or rmdir a file/directory. */ | |
1908 | static int may_link(struct inode *dir, | |
1909 | struct dentry *dentry, | |
1910 | int kind) | |
1911 | ||
1912 | { | |
1da177e4 | 1913 | struct inode_security_struct *dsec, *isec; |
2bf49690 | 1914 | struct common_audit_data ad; |
275bb41e | 1915 | u32 sid = current_sid(); |
1da177e4 LT |
1916 | u32 av; |
1917 | int rc; | |
1918 | ||
83da53c5 AG |
1919 | dsec = inode_security(dir); |
1920 | isec = backing_inode_security(dentry); | |
1da177e4 | 1921 | |
50c205f5 | 1922 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1923 | ad.u.dentry = dentry; |
1da177e4 LT |
1924 | |
1925 | av = DIR__SEARCH; | |
1926 | av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); | |
275bb41e | 1927 | rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); |
1da177e4 LT |
1928 | if (rc) |
1929 | return rc; | |
1930 | ||
1931 | switch (kind) { | |
1932 | case MAY_LINK: | |
1933 | av = FILE__LINK; | |
1934 | break; | |
1935 | case MAY_UNLINK: | |
1936 | av = FILE__UNLINK; | |
1937 | break; | |
1938 | case MAY_RMDIR: | |
1939 | av = DIR__RMDIR; | |
1940 | break; | |
1941 | default: | |
744ba35e EP |
1942 | printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", |
1943 | __func__, kind); | |
1da177e4 LT |
1944 | return 0; |
1945 | } | |
1946 | ||
275bb41e | 1947 | rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); |
1da177e4 LT |
1948 | return rc; |
1949 | } | |
1950 | ||
1951 | static inline int may_rename(struct inode *old_dir, | |
1952 | struct dentry *old_dentry, | |
1953 | struct inode *new_dir, | |
1954 | struct dentry *new_dentry) | |
1955 | { | |
1da177e4 | 1956 | struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; |
2bf49690 | 1957 | struct common_audit_data ad; |
275bb41e | 1958 | u32 sid = current_sid(); |
1da177e4 LT |
1959 | u32 av; |
1960 | int old_is_dir, new_is_dir; | |
1961 | int rc; | |
1962 | ||
83da53c5 AG |
1963 | old_dsec = inode_security(old_dir); |
1964 | old_isec = backing_inode_security(old_dentry); | |
e36cb0b8 | 1965 | old_is_dir = d_is_dir(old_dentry); |
83da53c5 | 1966 | new_dsec = inode_security(new_dir); |
1da177e4 | 1967 | |
50c205f5 | 1968 | ad.type = LSM_AUDIT_DATA_DENTRY; |
1da177e4 | 1969 | |
a269434d | 1970 | ad.u.dentry = old_dentry; |
275bb41e | 1971 | rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, |
1da177e4 LT |
1972 | DIR__REMOVE_NAME | DIR__SEARCH, &ad); |
1973 | if (rc) | |
1974 | return rc; | |
275bb41e | 1975 | rc = avc_has_perm(sid, old_isec->sid, |
1da177e4 LT |
1976 | old_isec->sclass, FILE__RENAME, &ad); |
1977 | if (rc) | |
1978 | return rc; | |
1979 | if (old_is_dir && new_dir != old_dir) { | |
275bb41e | 1980 | rc = avc_has_perm(sid, old_isec->sid, |
1da177e4 LT |
1981 | old_isec->sclass, DIR__REPARENT, &ad); |
1982 | if (rc) | |
1983 | return rc; | |
1984 | } | |
1985 | ||
a269434d | 1986 | ad.u.dentry = new_dentry; |
1da177e4 | 1987 | av = DIR__ADD_NAME | DIR__SEARCH; |
2c616d4d | 1988 | if (d_is_positive(new_dentry)) |
1da177e4 | 1989 | av |= DIR__REMOVE_NAME; |
275bb41e | 1990 | rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); |
1da177e4 LT |
1991 | if (rc) |
1992 | return rc; | |
2c616d4d | 1993 | if (d_is_positive(new_dentry)) { |
83da53c5 | 1994 | new_isec = backing_inode_security(new_dentry); |
e36cb0b8 | 1995 | new_is_dir = d_is_dir(new_dentry); |
275bb41e | 1996 | rc = avc_has_perm(sid, new_isec->sid, |
1da177e4 LT |
1997 | new_isec->sclass, |
1998 | (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); | |
1999 | if (rc) | |
2000 | return rc; | |
2001 | } | |
2002 | ||
2003 | return 0; | |
2004 | } | |
2005 | ||
2006 | /* Check whether a task can perform a filesystem operation. */ | |
88e67f3b | 2007 | static int superblock_has_perm(const struct cred *cred, |
1da177e4 LT |
2008 | struct super_block *sb, |
2009 | u32 perms, | |
2bf49690 | 2010 | struct common_audit_data *ad) |
1da177e4 | 2011 | { |
1da177e4 | 2012 | struct superblock_security_struct *sbsec; |
88e67f3b | 2013 | u32 sid = cred_sid(cred); |
1da177e4 | 2014 | |
33132849 | 2015 | sbsec = sb->s_security; |
275bb41e | 2016 | return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); |
1da177e4 LT |
2017 | } |
2018 | ||
2019 | /* Convert a Linux mode and permission mask to an access vector. */ | |
2020 | static inline u32 file_mask_to_av(int mode, int mask) | |
2021 | { | |
2022 | u32 av = 0; | |
2023 | ||
dba19c60 | 2024 | if (!S_ISDIR(mode)) { |
1da177e4 LT |
2025 | if (mask & MAY_EXEC) |
2026 | av |= FILE__EXECUTE; | |
2027 | if (mask & MAY_READ) | |
2028 | av |= FILE__READ; | |
2029 | ||
2030 | if (mask & MAY_APPEND) | |
2031 | av |= FILE__APPEND; | |
2032 | else if (mask & MAY_WRITE) | |
2033 | av |= FILE__WRITE; | |
2034 | ||
2035 | } else { | |
2036 | if (mask & MAY_EXEC) | |
2037 | av |= DIR__SEARCH; | |
2038 | if (mask & MAY_WRITE) | |
2039 | av |= DIR__WRITE; | |
2040 | if (mask & MAY_READ) | |
2041 | av |= DIR__READ; | |
2042 | } | |
2043 | ||
2044 | return av; | |
2045 | } | |
2046 | ||
8b6a5a37 EP |
2047 | /* Convert a Linux file to an access vector. */ |
2048 | static inline u32 file_to_av(struct file *file) | |
2049 | { | |
2050 | u32 av = 0; | |
2051 | ||
2052 | if (file->f_mode & FMODE_READ) | |
2053 | av |= FILE__READ; | |
2054 | if (file->f_mode & FMODE_WRITE) { | |
2055 | if (file->f_flags & O_APPEND) | |
2056 | av |= FILE__APPEND; | |
2057 | else | |
2058 | av |= FILE__WRITE; | |
2059 | } | |
2060 | if (!av) { | |
2061 | /* | |
2062 | * Special file opened with flags 3 for ioctl-only use. | |
2063 | */ | |
2064 | av = FILE__IOCTL; | |
2065 | } | |
2066 | ||
2067 | return av; | |
2068 | } | |
2069 | ||
b0c636b9 | 2070 | /* |
8b6a5a37 | 2071 | * Convert a file to an access vector and include the correct open |
b0c636b9 EP |
2072 | * open permission. |
2073 | */ | |
8b6a5a37 | 2074 | static inline u32 open_file_to_av(struct file *file) |
b0c636b9 | 2075 | { |
8b6a5a37 | 2076 | u32 av = file_to_av(file); |
ccb54478 | 2077 | struct inode *inode = file_inode(file); |
b0c636b9 | 2078 | |
ccb54478 | 2079 | if (selinux_policycap_openperm && inode->i_sb->s_magic != SOCKFS_MAGIC) |
49b7b8de EP |
2080 | av |= FILE__OPEN; |
2081 | ||
b0c636b9 EP |
2082 | return av; |
2083 | } | |
2084 | ||
1da177e4 LT |
2085 | /* Hook functions begin here. */ |
2086 | ||
79af7307 SS |
2087 | static int selinux_binder_set_context_mgr(struct task_struct *mgr) |
2088 | { | |
2089 | u32 mysid = current_sid(); | |
2090 | u32 mgrsid = task_sid(mgr); | |
2091 | ||
2092 | return avc_has_perm(mysid, mgrsid, SECCLASS_BINDER, | |
2093 | BINDER__SET_CONTEXT_MGR, NULL); | |
2094 | } | |
2095 | ||
2096 | static int selinux_binder_transaction(struct task_struct *from, | |
2097 | struct task_struct *to) | |
2098 | { | |
2099 | u32 mysid = current_sid(); | |
2100 | u32 fromsid = task_sid(from); | |
2101 | u32 tosid = task_sid(to); | |
2102 | int rc; | |
2103 | ||
2104 | if (mysid != fromsid) { | |
2105 | rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER, | |
2106 | BINDER__IMPERSONATE, NULL); | |
2107 | if (rc) | |
2108 | return rc; | |
2109 | } | |
2110 | ||
2111 | return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__CALL, | |
2112 | NULL); | |
2113 | } | |
2114 | ||
2115 | static int selinux_binder_transfer_binder(struct task_struct *from, | |
2116 | struct task_struct *to) | |
2117 | { | |
2118 | u32 fromsid = task_sid(from); | |
2119 | u32 tosid = task_sid(to); | |
2120 | ||
2121 | return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER, | |
2122 | NULL); | |
2123 | } | |
2124 | ||
2125 | static int selinux_binder_transfer_file(struct task_struct *from, | |
2126 | struct task_struct *to, | |
2127 | struct file *file) | |
2128 | { | |
2129 | u32 sid = task_sid(to); | |
004c5200 | 2130 | struct file_security_struct *fsec = selinux_file(file); |
83da53c5 | 2131 | struct dentry *dentry = file->f_path.dentry; |
20cdef8d | 2132 | struct inode_security_struct *isec; |
79af7307 SS |
2133 | struct common_audit_data ad; |
2134 | int rc; | |
2135 | ||
2136 | ad.type = LSM_AUDIT_DATA_PATH; | |
2137 | ad.u.path = file->f_path; | |
2138 | ||
2139 | if (sid != fsec->sid) { | |
2140 | rc = avc_has_perm(sid, fsec->sid, | |
2141 | SECCLASS_FD, | |
2142 | FD__USE, | |
2143 | &ad); | |
2144 | if (rc) | |
2145 | return rc; | |
2146 | } | |
2147 | ||
83da53c5 | 2148 | if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) |
79af7307 SS |
2149 | return 0; |
2150 | ||
20cdef8d | 2151 | isec = backing_inode_security(dentry); |
79af7307 SS |
2152 | return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file), |
2153 | &ad); | |
2154 | } | |
2155 | ||
9e48858f | 2156 | static int selinux_ptrace_access_check(struct task_struct *child, |
5cd9c58f | 2157 | unsigned int mode) |
1da177e4 | 2158 | { |
be0554c9 SS |
2159 | u32 sid = current_sid(); |
2160 | u32 csid = task_sid(child); | |
2161 | ||
2162 | if (mode & PTRACE_MODE_READ) | |
275bb41e | 2163 | return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); |
006ebb40 | 2164 | |
be0554c9 | 2165 | return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL); |
5cd9c58f DH |
2166 | } |
2167 | ||
2168 | static int selinux_ptrace_traceme(struct task_struct *parent) | |
2169 | { | |
be0554c9 SS |
2170 | return avc_has_perm(task_sid(parent), current_sid(), SECCLASS_PROCESS, |
2171 | PROCESS__PTRACE, NULL); | |
1da177e4 LT |
2172 | } |
2173 | ||
2174 | static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, | |
828dfe1d | 2175 | kernel_cap_t *inheritable, kernel_cap_t *permitted) |
1da177e4 | 2176 | { |
be0554c9 SS |
2177 | return avc_has_perm(current_sid(), task_sid(target), SECCLASS_PROCESS, |
2178 | PROCESS__GETCAP, NULL); | |
1da177e4 LT |
2179 | } |
2180 | ||
d84f4f99 DH |
2181 | static int selinux_capset(struct cred *new, const struct cred *old, |
2182 | const kernel_cap_t *effective, | |
2183 | const kernel_cap_t *inheritable, | |
2184 | const kernel_cap_t *permitted) | |
1da177e4 | 2185 | { |
be0554c9 SS |
2186 | return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS, |
2187 | PROCESS__SETCAP, NULL); | |
1da177e4 LT |
2188 | } |
2189 | ||
5626d3e8 JM |
2190 | /* |
2191 | * (This comment used to live with the selinux_task_setuid hook, | |
2192 | * which was removed). | |
2193 | * | |
2194 | * Since setuid only affects the current process, and since the SELinux | |
2195 | * controls are not based on the Linux identity attributes, SELinux does not | |
2196 | * need to control this operation. However, SELinux does control the use of | |
2197 | * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. | |
2198 | */ | |
2199 | ||
6a9de491 EP |
2200 | static int selinux_capable(const struct cred *cred, struct user_namespace *ns, |
2201 | int cap, int audit) | |
1da177e4 | 2202 | { |
8e4ff6f2 | 2203 | return cred_has_capability(cred, cap, audit, ns == &init_user_ns); |
1da177e4 LT |
2204 | } |
2205 | ||
1da177e4 LT |
2206 | static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) |
2207 | { | |
88e67f3b | 2208 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2209 | int rc = 0; |
2210 | ||
2211 | if (!sb) | |
2212 | return 0; | |
2213 | ||
2214 | switch (cmds) { | |
828dfe1d EP |
2215 | case Q_SYNC: |
2216 | case Q_QUOTAON: | |
2217 | case Q_QUOTAOFF: | |
2218 | case Q_SETINFO: | |
2219 | case Q_SETQUOTA: | |
88e67f3b | 2220 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); |
828dfe1d EP |
2221 | break; |
2222 | case Q_GETFMT: | |
2223 | case Q_GETINFO: | |
2224 | case Q_GETQUOTA: | |
88e67f3b | 2225 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); |
828dfe1d EP |
2226 | break; |
2227 | default: | |
2228 | rc = 0; /* let the kernel handle invalid cmds */ | |
2229 | break; | |
1da177e4 LT |
2230 | } |
2231 | return rc; | |
2232 | } | |
2233 | ||
2234 | static int selinux_quota_on(struct dentry *dentry) | |
2235 | { | |
88e67f3b DH |
2236 | const struct cred *cred = current_cred(); |
2237 | ||
2875fa00 | 2238 | return dentry_has_perm(cred, dentry, FILE__QUOTAON); |
1da177e4 LT |
2239 | } |
2240 | ||
12b3052c | 2241 | static int selinux_syslog(int type) |
1da177e4 | 2242 | { |
1da177e4 | 2243 | switch (type) { |
d78ca3cd KC |
2244 | case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ |
2245 | case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ | |
be0554c9 SS |
2246 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, |
2247 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL); | |
d78ca3cd KC |
2248 | case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ |
2249 | case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ | |
2250 | /* Set level of messages printed to console */ | |
2251 | case SYSLOG_ACTION_CONSOLE_LEVEL: | |
be0554c9 SS |
2252 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, |
2253 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, | |
2254 | NULL); | |
1da177e4 | 2255 | } |
be0554c9 SS |
2256 | /* All other syslog types */ |
2257 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, | |
2258 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL); | |
1da177e4 LT |
2259 | } |
2260 | ||
2261 | /* | |
2262 | * Check that a process has enough memory to allocate a new virtual | |
2263 | * mapping. 0 means there is enough memory for the allocation to | |
2264 | * succeed and -ENOMEM implies there is not. | |
2265 | * | |
1da177e4 LT |
2266 | * Do not audit the selinux permission check, as this is applied to all |
2267 | * processes that allocate mappings. | |
2268 | */ | |
34b4e4aa | 2269 | static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
2270 | { |
2271 | int rc, cap_sys_admin = 0; | |
1da177e4 | 2272 | |
b1d9e6b0 | 2273 | rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN, |
8e4ff6f2 | 2274 | SECURITY_CAP_NOAUDIT, true); |
1da177e4 LT |
2275 | if (rc == 0) |
2276 | cap_sys_admin = 1; | |
2277 | ||
b1d9e6b0 | 2278 | return cap_sys_admin; |
1da177e4 LT |
2279 | } |
2280 | ||
2281 | /* binprm security operations */ | |
2282 | ||
be0554c9 | 2283 | static u32 ptrace_parent_sid(void) |
0c6181cb PM |
2284 | { |
2285 | u32 sid = 0; | |
2286 | struct task_struct *tracer; | |
2287 | ||
2288 | rcu_read_lock(); | |
be0554c9 | 2289 | tracer = ptrace_parent(current); |
0c6181cb PM |
2290 | if (tracer) |
2291 | sid = task_sid(tracer); | |
2292 | rcu_read_unlock(); | |
2293 | ||
2294 | return sid; | |
2295 | } | |
2296 | ||
7b0d0b40 SS |
2297 | static int check_nnp_nosuid(const struct linux_binprm *bprm, |
2298 | const struct task_security_struct *old_tsec, | |
2299 | const struct task_security_struct *new_tsec) | |
2300 | { | |
2301 | int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); | |
0dc04886 | 2302 | int nosuid = path_nosuid(&bprm->file->f_path); |
7b0d0b40 SS |
2303 | int rc; |
2304 | ||
2305 | if (!nnp && !nosuid) | |
2306 | return 0; /* neither NNP nor nosuid */ | |
2307 | ||
2308 | if (new_tsec->sid == old_tsec->sid) | |
2309 | return 0; /* No change in credentials */ | |
2310 | ||
2311 | /* | |
2312 | * The only transitions we permit under NNP or nosuid | |
2313 | * are transitions to bounded SIDs, i.e. SIDs that are | |
2314 | * guaranteed to only be allowed a subset of the permissions | |
2315 | * of the current SID. | |
2316 | */ | |
2317 | rc = security_bounded_transition(old_tsec->sid, new_tsec->sid); | |
2318 | if (rc) { | |
2319 | /* | |
2320 | * On failure, preserve the errno values for NNP vs nosuid. | |
2321 | * NNP: Operation not permitted for caller. | |
2322 | * nosuid: Permission denied to file. | |
2323 | */ | |
2324 | if (nnp) | |
2325 | return -EPERM; | |
2326 | else | |
2327 | return -EACCES; | |
2328 | } | |
2329 | return 0; | |
2330 | } | |
2331 | ||
a6f76f23 | 2332 | static int selinux_bprm_set_creds(struct linux_binprm *bprm) |
1da177e4 | 2333 | { |
a6f76f23 DH |
2334 | const struct task_security_struct *old_tsec; |
2335 | struct task_security_struct *new_tsec; | |
1da177e4 | 2336 | struct inode_security_struct *isec; |
2bf49690 | 2337 | struct common_audit_data ad; |
496ad9aa | 2338 | struct inode *inode = file_inode(bprm->file); |
1da177e4 LT |
2339 | int rc; |
2340 | ||
a6f76f23 DH |
2341 | /* SELinux context only depends on initial program or script and not |
2342 | * the script interpreter */ | |
2343 | if (bprm->cred_prepared) | |
1da177e4 LT |
2344 | return 0; |
2345 | ||
98738d70 CS |
2346 | old_tsec = selinux_cred(current_cred()); |
2347 | new_tsec = selinux_cred(bprm->cred); | |
83da53c5 | 2348 | isec = inode_security(inode); |
1da177e4 LT |
2349 | |
2350 | /* Default to the current task SID. */ | |
a6f76f23 DH |
2351 | new_tsec->sid = old_tsec->sid; |
2352 | new_tsec->osid = old_tsec->sid; | |
1da177e4 | 2353 | |
28eba5bf | 2354 | /* Reset fs, key, and sock SIDs on execve. */ |
a6f76f23 DH |
2355 | new_tsec->create_sid = 0; |
2356 | new_tsec->keycreate_sid = 0; | |
2357 | new_tsec->sockcreate_sid = 0; | |
1da177e4 | 2358 | |
a6f76f23 DH |
2359 | if (old_tsec->exec_sid) { |
2360 | new_tsec->sid = old_tsec->exec_sid; | |
1da177e4 | 2361 | /* Reset exec SID on execve. */ |
a6f76f23 | 2362 | new_tsec->exec_sid = 0; |
259e5e6c | 2363 | |
7b0d0b40 SS |
2364 | /* Fail on NNP or nosuid if not an allowed transition. */ |
2365 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2366 | if (rc) | |
2367 | return rc; | |
1da177e4 LT |
2368 | } else { |
2369 | /* Check for a default transition on this program. */ | |
a6f76f23 | 2370 | rc = security_transition_sid(old_tsec->sid, isec->sid, |
652bb9b0 EP |
2371 | SECCLASS_PROCESS, NULL, |
2372 | &new_tsec->sid); | |
1da177e4 LT |
2373 | if (rc) |
2374 | return rc; | |
7b0d0b40 SS |
2375 | |
2376 | /* | |
2377 | * Fallback to old SID on NNP or nosuid if not an allowed | |
2378 | * transition. | |
2379 | */ | |
2380 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2381 | if (rc) | |
2382 | new_tsec->sid = old_tsec->sid; | |
1da177e4 LT |
2383 | } |
2384 | ||
43af5de7 VG |
2385 | ad.type = LSM_AUDIT_DATA_FILE; |
2386 | ad.u.file = bprm->file; | |
1da177e4 | 2387 | |
a6f76f23 DH |
2388 | if (new_tsec->sid == old_tsec->sid) { |
2389 | rc = avc_has_perm(old_tsec->sid, isec->sid, | |
1da177e4 LT |
2390 | SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); |
2391 | if (rc) | |
2392 | return rc; | |
2393 | } else { | |
2394 | /* Check permissions for the transition. */ | |
a6f76f23 | 2395 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, |
1da177e4 LT |
2396 | SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); |
2397 | if (rc) | |
2398 | return rc; | |
2399 | ||
a6f76f23 | 2400 | rc = avc_has_perm(new_tsec->sid, isec->sid, |
1da177e4 LT |
2401 | SECCLASS_FILE, FILE__ENTRYPOINT, &ad); |
2402 | if (rc) | |
2403 | return rc; | |
2404 | ||
a6f76f23 DH |
2405 | /* Check for shared state */ |
2406 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
2407 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, | |
2408 | SECCLASS_PROCESS, PROCESS__SHARE, | |
2409 | NULL); | |
2410 | if (rc) | |
2411 | return -EPERM; | |
2412 | } | |
2413 | ||
2414 | /* Make sure that anyone attempting to ptrace over a task that | |
2415 | * changes its SID has the appropriate permit */ | |
9227dd2a | 2416 | if (bprm->unsafe & LSM_UNSAFE_PTRACE) { |
be0554c9 | 2417 | u32 ptsid = ptrace_parent_sid(); |
a6f76f23 DH |
2418 | if (ptsid != 0) { |
2419 | rc = avc_has_perm(ptsid, new_tsec->sid, | |
2420 | SECCLASS_PROCESS, | |
2421 | PROCESS__PTRACE, NULL); | |
2422 | if (rc) | |
2423 | return -EPERM; | |
2424 | } | |
2425 | } | |
1da177e4 | 2426 | |
a6f76f23 DH |
2427 | /* Clear any possibly unsafe personality bits on exec: */ |
2428 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
1da177e4 LT |
2429 | } |
2430 | ||
1da177e4 LT |
2431 | return 0; |
2432 | } | |
2433 | ||
828dfe1d | 2434 | static int selinux_bprm_secureexec(struct linux_binprm *bprm) |
1da177e4 | 2435 | { |
98738d70 | 2436 | const struct task_security_struct *tsec = selinux_cred(current_cred()); |
275bb41e | 2437 | u32 sid, osid; |
1da177e4 LT |
2438 | int atsecure = 0; |
2439 | ||
275bb41e DH |
2440 | sid = tsec->sid; |
2441 | osid = tsec->osid; | |
2442 | ||
2443 | if (osid != sid) { | |
1da177e4 LT |
2444 | /* Enable secure mode for SIDs transitions unless |
2445 | the noatsecure permission is granted between | |
2446 | the two SIDs, i.e. ahp returns 0. */ | |
275bb41e | 2447 | atsecure = avc_has_perm(osid, sid, |
a6f76f23 DH |
2448 | SECCLASS_PROCESS, |
2449 | PROCESS__NOATSECURE, NULL); | |
1da177e4 LT |
2450 | } |
2451 | ||
b1d9e6b0 | 2452 | return !!atsecure; |
1da177e4 LT |
2453 | } |
2454 | ||
c3c073f8 AV |
2455 | static int match_file(const void *p, struct file *file, unsigned fd) |
2456 | { | |
2457 | return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; | |
2458 | } | |
2459 | ||
1da177e4 | 2460 | /* Derived from fs/exec.c:flush_old_files. */ |
745ca247 DH |
2461 | static inline void flush_unauthorized_files(const struct cred *cred, |
2462 | struct files_struct *files) | |
1da177e4 | 2463 | { |
1da177e4 | 2464 | struct file *file, *devnull = NULL; |
b20c8122 | 2465 | struct tty_struct *tty; |
24ec839c | 2466 | int drop_tty = 0; |
c3c073f8 | 2467 | unsigned n; |
1da177e4 | 2468 | |
24ec839c | 2469 | tty = get_current_tty(); |
1da177e4 | 2470 | if (tty) { |
4a510969 | 2471 | spin_lock(&tty->files_lock); |
37dd0bd0 | 2472 | if (!list_empty(&tty->tty_files)) { |
d996b62a | 2473 | struct tty_file_private *file_priv; |
37dd0bd0 | 2474 | |
1da177e4 | 2475 | /* Revalidate access to controlling tty. |
13f8e981 DH |
2476 | Use file_path_has_perm on the tty path directly |
2477 | rather than using file_has_perm, as this particular | |
2478 | open file may belong to another process and we are | |
2479 | only interested in the inode-based check here. */ | |
d996b62a NP |
2480 | file_priv = list_first_entry(&tty->tty_files, |
2481 | struct tty_file_private, list); | |
2482 | file = file_priv->file; | |
13f8e981 | 2483 | if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE)) |
24ec839c | 2484 | drop_tty = 1; |
1da177e4 | 2485 | } |
4a510969 | 2486 | spin_unlock(&tty->files_lock); |
452a00d2 | 2487 | tty_kref_put(tty); |
1da177e4 | 2488 | } |
98a27ba4 EB |
2489 | /* Reset controlling tty. */ |
2490 | if (drop_tty) | |
2491 | no_tty(); | |
1da177e4 LT |
2492 | |
2493 | /* Revalidate access to inherited open files. */ | |
c3c073f8 AV |
2494 | n = iterate_fd(files, 0, match_file, cred); |
2495 | if (!n) /* none found? */ | |
2496 | return; | |
1da177e4 | 2497 | |
c3c073f8 | 2498 | devnull = dentry_open(&selinux_null, O_RDWR, cred); |
45525b26 AV |
2499 | if (IS_ERR(devnull)) |
2500 | devnull = NULL; | |
2501 | /* replace all the matching ones with this */ | |
2502 | do { | |
2503 | replace_fd(n - 1, devnull, 0); | |
2504 | } while ((n = iterate_fd(files, n, match_file, cred)) != 0); | |
2505 | if (devnull) | |
c3c073f8 | 2506 | fput(devnull); |
1da177e4 LT |
2507 | } |
2508 | ||
a6f76f23 DH |
2509 | /* |
2510 | * Prepare a process for imminent new credential changes due to exec | |
2511 | */ | |
2512 | static void selinux_bprm_committing_creds(struct linux_binprm *bprm) | |
1da177e4 | 2513 | { |
a6f76f23 DH |
2514 | struct task_security_struct *new_tsec; |
2515 | struct rlimit *rlim, *initrlim; | |
2516 | int rc, i; | |
d84f4f99 | 2517 | |
98738d70 | 2518 | new_tsec = selinux_cred(bprm->cred); |
a6f76f23 DH |
2519 | if (new_tsec->sid == new_tsec->osid) |
2520 | return; | |
1da177e4 | 2521 | |
a6f76f23 DH |
2522 | /* Close files for which the new task SID is not authorized. */ |
2523 | flush_unauthorized_files(bprm->cred, current->files); | |
0356357c | 2524 | |
a6f76f23 DH |
2525 | /* Always clear parent death signal on SID transitions. */ |
2526 | current->pdeath_signal = 0; | |
0356357c | 2527 | |
a6f76f23 DH |
2528 | /* Check whether the new SID can inherit resource limits from the old |
2529 | * SID. If not, reset all soft limits to the lower of the current | |
2530 | * task's hard limit and the init task's soft limit. | |
2531 | * | |
2532 | * Note that the setting of hard limits (even to lower them) can be | |
2533 | * controlled by the setrlimit check. The inclusion of the init task's | |
2534 | * soft limit into the computation is to avoid resetting soft limits | |
2535 | * higher than the default soft limit for cases where the default is | |
2536 | * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. | |
2537 | */ | |
2538 | rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, | |
2539 | PROCESS__RLIMITINH, NULL); | |
2540 | if (rc) { | |
eb2d55a3 ON |
2541 | /* protect against do_prlimit() */ |
2542 | task_lock(current); | |
a6f76f23 DH |
2543 | for (i = 0; i < RLIM_NLIMITS; i++) { |
2544 | rlim = current->signal->rlim + i; | |
2545 | initrlim = init_task.signal->rlim + i; | |
2546 | rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); | |
1da177e4 | 2547 | } |
eb2d55a3 | 2548 | task_unlock(current); |
baa73d9e NP |
2549 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) |
2550 | update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); | |
1da177e4 LT |
2551 | } |
2552 | } | |
2553 | ||
2554 | /* | |
a6f76f23 DH |
2555 | * Clean up the process immediately after the installation of new credentials |
2556 | * due to exec | |
1da177e4 | 2557 | */ |
a6f76f23 | 2558 | static void selinux_bprm_committed_creds(struct linux_binprm *bprm) |
1da177e4 | 2559 | { |
98738d70 | 2560 | const struct task_security_struct *tsec = selinux_cred(current_cred()); |
1da177e4 | 2561 | struct itimerval itimer; |
a6f76f23 | 2562 | u32 osid, sid; |
1da177e4 LT |
2563 | int rc, i; |
2564 | ||
a6f76f23 DH |
2565 | osid = tsec->osid; |
2566 | sid = tsec->sid; | |
2567 | ||
2568 | if (sid == osid) | |
1da177e4 LT |
2569 | return; |
2570 | ||
a6f76f23 DH |
2571 | /* Check whether the new SID can inherit signal state from the old SID. |
2572 | * If not, clear itimers to avoid subsequent signal generation and | |
2573 | * flush and unblock signals. | |
2574 | * | |
2575 | * This must occur _after_ the task SID has been updated so that any | |
2576 | * kill done after the flush will be checked against the new SID. | |
2577 | */ | |
2578 | rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); | |
1da177e4 | 2579 | if (rc) { |
baa73d9e NP |
2580 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) { |
2581 | memset(&itimer, 0, sizeof itimer); | |
2582 | for (i = 0; i < 3; i++) | |
2583 | do_setitimer(i, &itimer, NULL); | |
2584 | } | |
1da177e4 | 2585 | spin_lock_irq(¤t->sighand->siglock); |
9e7c8f8c ON |
2586 | if (!fatal_signal_pending(current)) { |
2587 | flush_sigqueue(¤t->pending); | |
2588 | flush_sigqueue(¤t->signal->shared_pending); | |
3bcac026 DH |
2589 | flush_signal_handlers(current, 1); |
2590 | sigemptyset(¤t->blocked); | |
9e7c8f8c | 2591 | recalc_sigpending(); |
3bcac026 | 2592 | } |
1da177e4 LT |
2593 | spin_unlock_irq(¤t->sighand->siglock); |
2594 | } | |
2595 | ||
a6f76f23 DH |
2596 | /* Wake up the parent if it is waiting so that it can recheck |
2597 | * wait permission to the new task SID. */ | |
ecd6de3c | 2598 | read_lock(&tasklist_lock); |
0b7570e7 | 2599 | __wake_up_parent(current, current->real_parent); |
ecd6de3c | 2600 | read_unlock(&tasklist_lock); |
1da177e4 LT |
2601 | } |
2602 | ||
2603 | /* superblock security operations */ | |
2604 | ||
2605 | static int selinux_sb_alloc_security(struct super_block *sb) | |
2606 | { | |
2607 | return superblock_alloc_security(sb); | |
2608 | } | |
2609 | ||
33132849 JS |
2610 | static void selinux_sb_free_security(struct super_block *sb) |
2611 | { | |
2612 | superblock_free_security(sb); | |
2613 | } | |
2614 | ||
1da177e4 LT |
2615 | static inline int match_prefix(char *prefix, int plen, char *option, int olen) |
2616 | { | |
2617 | if (plen > olen) | |
2618 | return 0; | |
2619 | ||
2620 | return !memcmp(prefix, option, plen); | |
2621 | } | |
2622 | ||
2623 | static inline int selinux_option(char *option, int len) | |
2624 | { | |
832cbd9a EP |
2625 | return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || |
2626 | match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || | |
2627 | match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || | |
11689d47 DQ |
2628 | match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || |
2629 | match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); | |
1da177e4 LT |
2630 | } |
2631 | ||
2632 | static inline void take_option(char **to, char *from, int *first, int len) | |
2633 | { | |
2634 | if (!*first) { | |
2635 | **to = ','; | |
2636 | *to += 1; | |
3528a953 | 2637 | } else |
1da177e4 LT |
2638 | *first = 0; |
2639 | memcpy(*to, from, len); | |
2640 | *to += len; | |
2641 | } | |
2642 | ||
828dfe1d EP |
2643 | static inline void take_selinux_option(char **to, char *from, int *first, |
2644 | int len) | |
3528a953 CO |
2645 | { |
2646 | int current_size = 0; | |
2647 | ||
2648 | if (!*first) { | |
2649 | **to = '|'; | |
2650 | *to += 1; | |
828dfe1d | 2651 | } else |
3528a953 CO |
2652 | *first = 0; |
2653 | ||
2654 | while (current_size < len) { | |
2655 | if (*from != '"') { | |
2656 | **to = *from; | |
2657 | *to += 1; | |
2658 | } | |
2659 | from += 1; | |
2660 | current_size += 1; | |
2661 | } | |
2662 | } | |
2663 | ||
e0007529 | 2664 | static int selinux_sb_copy_data(char *orig, char *copy) |
1da177e4 LT |
2665 | { |
2666 | int fnosec, fsec, rc = 0; | |
2667 | char *in_save, *in_curr, *in_end; | |
2668 | char *sec_curr, *nosec_save, *nosec; | |
3528a953 | 2669 | int open_quote = 0; |
1da177e4 LT |
2670 | |
2671 | in_curr = orig; | |
2672 | sec_curr = copy; | |
2673 | ||
1da177e4 LT |
2674 | nosec = (char *)get_zeroed_page(GFP_KERNEL); |
2675 | if (!nosec) { | |
2676 | rc = -ENOMEM; | |
2677 | goto out; | |
2678 | } | |
2679 | ||
2680 | nosec_save = nosec; | |
2681 | fnosec = fsec = 1; | |
2682 | in_save = in_end = orig; | |
2683 | ||
2684 | do { | |
3528a953 CO |
2685 | if (*in_end == '"') |
2686 | open_quote = !open_quote; | |
2687 | if ((*in_end == ',' && open_quote == 0) || | |
2688 | *in_end == '\0') { | |
1da177e4 LT |
2689 | int len = in_end - in_curr; |
2690 | ||
2691 | if (selinux_option(in_curr, len)) | |
3528a953 | 2692 | take_selinux_option(&sec_curr, in_curr, &fsec, len); |
1da177e4 LT |
2693 | else |
2694 | take_option(&nosec, in_curr, &fnosec, len); | |
2695 | ||
2696 | in_curr = in_end + 1; | |
2697 | } | |
2698 | } while (*in_end++); | |
2699 | ||
6931dfc9 | 2700 | strcpy(in_save, nosec_save); |
da3caa20 | 2701 | free_page((unsigned long)nosec_save); |
1da177e4 LT |
2702 | out: |
2703 | return rc; | |
2704 | } | |
2705 | ||
026eb167 EP |
2706 | static int selinux_sb_remount(struct super_block *sb, void *data) |
2707 | { | |
2708 | int rc, i, *flags; | |
2709 | struct security_mnt_opts opts; | |
2710 | char *secdata, **mount_options; | |
33132849 | 2711 | struct superblock_security_struct *sbsec = sb->s_security; |
026eb167 EP |
2712 | |
2713 | if (!(sbsec->flags & SE_SBINITIALIZED)) | |
2714 | return 0; | |
2715 | ||
2716 | if (!data) | |
2717 | return 0; | |
2718 | ||
2719 | if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) | |
2720 | return 0; | |
2721 | ||
2722 | security_init_mnt_opts(&opts); | |
2723 | secdata = alloc_secdata(); | |
2724 | if (!secdata) | |
2725 | return -ENOMEM; | |
2726 | rc = selinux_sb_copy_data(data, secdata); | |
2727 | if (rc) | |
2728 | goto out_free_secdata; | |
2729 | ||
2730 | rc = selinux_parse_opts_str(secdata, &opts); | |
2731 | if (rc) | |
2732 | goto out_free_secdata; | |
2733 | ||
2734 | mount_options = opts.mnt_opts; | |
2735 | flags = opts.mnt_opts_flags; | |
2736 | ||
2737 | for (i = 0; i < opts.num_mnt_opts; i++) { | |
2738 | u32 sid; | |
026eb167 | 2739 | |
12f348b9 | 2740 | if (flags[i] == SBLABEL_MNT) |
026eb167 | 2741 | continue; |
44be2f65 | 2742 | rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL); |
026eb167 | 2743 | if (rc) { |
44be2f65 | 2744 | printk(KERN_WARNING "SELinux: security_context_str_to_sid" |
29b1deb2 LT |
2745 | "(%s) failed for (dev %s, type %s) errno=%d\n", |
2746 | mount_options[i], sb->s_id, sb->s_type->name, rc); | |
026eb167 EP |
2747 | goto out_free_opts; |
2748 | } | |
2749 | rc = -EINVAL; | |
2750 | switch (flags[i]) { | |
2751 | case FSCONTEXT_MNT: | |
2752 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) | |
2753 | goto out_bad_option; | |
2754 | break; | |
2755 | case CONTEXT_MNT: | |
2756 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) | |
2757 | goto out_bad_option; | |
2758 | break; | |
2759 | case ROOTCONTEXT_MNT: { | |
2760 | struct inode_security_struct *root_isec; | |
83da53c5 | 2761 | root_isec = backing_inode_security(sb->s_root); |
026eb167 EP |
2762 | |
2763 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) | |
2764 | goto out_bad_option; | |
2765 | break; | |
2766 | } | |
2767 | case DEFCONTEXT_MNT: | |
2768 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) | |
2769 | goto out_bad_option; | |
2770 | break; | |
2771 | default: | |
2772 | goto out_free_opts; | |
2773 | } | |
2774 | } | |
2775 | ||
2776 | rc = 0; | |
2777 | out_free_opts: | |
2778 | security_free_mnt_opts(&opts); | |
2779 | out_free_secdata: | |
2780 | free_secdata(secdata); | |
2781 | return rc; | |
2782 | out_bad_option: | |
2783 | printk(KERN_WARNING "SELinux: unable to change security options " | |
29b1deb2 LT |
2784 | "during remount (dev %s, type=%s)\n", sb->s_id, |
2785 | sb->s_type->name); | |
026eb167 EP |
2786 | goto out_free_opts; |
2787 | } | |
2788 | ||
12204e24 | 2789 | static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) |
1da177e4 | 2790 | { |
88e67f3b | 2791 | const struct cred *cred = current_cred(); |
2bf49690 | 2792 | struct common_audit_data ad; |
1da177e4 LT |
2793 | int rc; |
2794 | ||
2795 | rc = superblock_doinit(sb, data); | |
2796 | if (rc) | |
2797 | return rc; | |
2798 | ||
74192246 JM |
2799 | /* Allow all mounts performed by the kernel */ |
2800 | if (flags & MS_KERNMOUNT) | |
2801 | return 0; | |
2802 | ||
50c205f5 | 2803 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2804 | ad.u.dentry = sb->s_root; |
88e67f3b | 2805 | return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); |
1da177e4 LT |
2806 | } |
2807 | ||
726c3342 | 2808 | static int selinux_sb_statfs(struct dentry *dentry) |
1da177e4 | 2809 | { |
88e67f3b | 2810 | const struct cred *cred = current_cred(); |
2bf49690 | 2811 | struct common_audit_data ad; |
1da177e4 | 2812 | |
50c205f5 | 2813 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2814 | ad.u.dentry = dentry->d_sb->s_root; |
88e67f3b | 2815 | return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); |
1da177e4 LT |
2816 | } |
2817 | ||
808d4e3c | 2818 | static int selinux_mount(const char *dev_name, |
8a04c43b | 2819 | const struct path *path, |
808d4e3c | 2820 | const char *type, |
828dfe1d EP |
2821 | unsigned long flags, |
2822 | void *data) | |
1da177e4 | 2823 | { |
88e67f3b | 2824 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2825 | |
2826 | if (flags & MS_REMOUNT) | |
d8c9584e | 2827 | return superblock_has_perm(cred, path->dentry->d_sb, |
828dfe1d | 2828 | FILESYSTEM__REMOUNT, NULL); |
1da177e4 | 2829 | else |
2875fa00 | 2830 | return path_has_perm(cred, path, FILE__MOUNTON); |
1da177e4 LT |
2831 | } |
2832 | ||
2833 | static int selinux_umount(struct vfsmount *mnt, int flags) | |
2834 | { | |
88e67f3b | 2835 | const struct cred *cred = current_cred(); |
1da177e4 | 2836 | |
88e67f3b | 2837 | return superblock_has_perm(cred, mnt->mnt_sb, |
828dfe1d | 2838 | FILESYSTEM__UNMOUNT, NULL); |
1da177e4 LT |
2839 | } |
2840 | ||
2841 | /* inode security operations */ | |
2842 | ||
2843 | static int selinux_inode_alloc_security(struct inode *inode) | |
2844 | { | |
2845 | return inode_alloc_security(inode); | |
2846 | } | |
2847 | ||
2848 | static void selinux_inode_free_security(struct inode *inode) | |
2849 | { | |
2850 | inode_free_security(inode); | |
2851 | } | |
2852 | ||
d47be3df | 2853 | static int selinux_dentry_init_security(struct dentry *dentry, int mode, |
4f3ccd76 | 2854 | const struct qstr *name, void **ctx, |
d47be3df DQ |
2855 | u32 *ctxlen) |
2856 | { | |
d47be3df DQ |
2857 | u32 newsid; |
2858 | int rc; | |
2859 | ||
98738d70 | 2860 | rc = selinux_determine_inode_label(selinux_cred(current_cred()), |
c957f6df | 2861 | d_inode(dentry->d_parent), name, |
c3c188b2 DH |
2862 | inode_mode_to_security_class(mode), |
2863 | &newsid); | |
2864 | if (rc) | |
2865 | return rc; | |
d47be3df DQ |
2866 | |
2867 | return security_sid_to_context(newsid, (char **)ctx, ctxlen); | |
2868 | } | |
2869 | ||
a518b0a5 VG |
2870 | static int selinux_dentry_create_files_as(struct dentry *dentry, int mode, |
2871 | struct qstr *name, | |
2872 | const struct cred *old, | |
2873 | struct cred *new) | |
2874 | { | |
2875 | u32 newsid; | |
2876 | int rc; | |
2877 | struct task_security_struct *tsec; | |
2878 | ||
98738d70 | 2879 | rc = selinux_determine_inode_label(selinux_cred(old), |
a518b0a5 VG |
2880 | d_inode(dentry->d_parent), name, |
2881 | inode_mode_to_security_class(mode), | |
2882 | &newsid); | |
2883 | if (rc) | |
2884 | return rc; | |
2885 | ||
98738d70 | 2886 | tsec = selinux_cred(new); |
a518b0a5 VG |
2887 | tsec->create_sid = newsid; |
2888 | return 0; | |
2889 | } | |
2890 | ||
5e41ff9e | 2891 | static int selinux_inode_init_security(struct inode *inode, struct inode *dir, |
9548906b TH |
2892 | const struct qstr *qstr, |
2893 | const char **name, | |
2a7dba39 | 2894 | void **value, size_t *len) |
5e41ff9e | 2895 | { |
98738d70 | 2896 | const struct task_security_struct *tsec = selinux_cred(current_cred()); |
5e41ff9e | 2897 | struct superblock_security_struct *sbsec; |
275bb41e | 2898 | u32 sid, newsid, clen; |
5e41ff9e | 2899 | int rc; |
9548906b | 2900 | char *context; |
5e41ff9e | 2901 | |
33132849 | 2902 | sbsec = dir->i_sb->s_security; |
5e41ff9e | 2903 | |
275bb41e DH |
2904 | sid = tsec->sid; |
2905 | newsid = tsec->create_sid; | |
2906 | ||
98738d70 | 2907 | rc = selinux_determine_inode_label(selinux_cred(current_cred()), |
c3c188b2 DH |
2908 | dir, qstr, |
2909 | inode_mode_to_security_class(inode->i_mode), | |
2910 | &newsid); | |
2911 | if (rc) | |
2912 | return rc; | |
5e41ff9e | 2913 | |
296fddf7 | 2914 | /* Possibly defer initialization to selinux_complete_init. */ |
0d90a7ec | 2915 | if (sbsec->flags & SE_SBINITIALIZED) { |
33132849 | 2916 | struct inode_security_struct *isec = inode->i_security; |
296fddf7 EP |
2917 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
2918 | isec->sid = newsid; | |
6f3be9f5 | 2919 | isec->initialized = LABEL_INITIALIZED; |
296fddf7 | 2920 | } |
5e41ff9e | 2921 | |
12f348b9 | 2922 | if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT)) |
25a74f3b SS |
2923 | return -EOPNOTSUPP; |
2924 | ||
9548906b TH |
2925 | if (name) |
2926 | *name = XATTR_SELINUX_SUFFIX; | |
5e41ff9e | 2927 | |
570bc1c2 | 2928 | if (value && len) { |
12b29f34 | 2929 | rc = security_sid_to_context_force(newsid, &context, &clen); |
9548906b | 2930 | if (rc) |
570bc1c2 | 2931 | return rc; |
570bc1c2 SS |
2932 | *value = context; |
2933 | *len = clen; | |
5e41ff9e | 2934 | } |
5e41ff9e | 2935 | |
5e41ff9e SS |
2936 | return 0; |
2937 | } | |
2938 | ||
4acdaf27 | 2939 | static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
2940 | { |
2941 | return may_create(dir, dentry, SECCLASS_FILE); | |
2942 | } | |
2943 | ||
1da177e4 LT |
2944 | static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) |
2945 | { | |
1da177e4 LT |
2946 | return may_link(dir, old_dentry, MAY_LINK); |
2947 | } | |
2948 | ||
1da177e4 LT |
2949 | static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) |
2950 | { | |
1da177e4 LT |
2951 | return may_link(dir, dentry, MAY_UNLINK); |
2952 | } | |
2953 | ||
2954 | static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) | |
2955 | { | |
2956 | return may_create(dir, dentry, SECCLASS_LNK_FILE); | |
2957 | } | |
2958 | ||
18bb1db3 | 2959 | static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) |
1da177e4 LT |
2960 | { |
2961 | return may_create(dir, dentry, SECCLASS_DIR); | |
2962 | } | |
2963 | ||
1da177e4 LT |
2964 | static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) |
2965 | { | |
2966 | return may_link(dir, dentry, MAY_RMDIR); | |
2967 | } | |
2968 | ||
1a67aafb | 2969 | static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 | 2970 | { |
1da177e4 LT |
2971 | return may_create(dir, dentry, inode_mode_to_security_class(mode)); |
2972 | } | |
2973 | ||
1da177e4 | 2974 | static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, |
828dfe1d | 2975 | struct inode *new_inode, struct dentry *new_dentry) |
1da177e4 LT |
2976 | { |
2977 | return may_rename(old_inode, old_dentry, new_inode, new_dentry); | |
2978 | } | |
2979 | ||
1da177e4 LT |
2980 | static int selinux_inode_readlink(struct dentry *dentry) |
2981 | { | |
88e67f3b DH |
2982 | const struct cred *cred = current_cred(); |
2983 | ||
2875fa00 | 2984 | return dentry_has_perm(cred, dentry, FILE__READ); |
1da177e4 LT |
2985 | } |
2986 | ||
bda0be7a N |
2987 | static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, |
2988 | bool rcu) | |
1da177e4 | 2989 | { |
88e67f3b | 2990 | const struct cred *cred = current_cred(); |
bda0be7a N |
2991 | struct common_audit_data ad; |
2992 | struct inode_security_struct *isec; | |
2993 | u32 sid; | |
1da177e4 | 2994 | |
bda0be7a N |
2995 | validate_creds(cred); |
2996 | ||
2997 | ad.type = LSM_AUDIT_DATA_DENTRY; | |
2998 | ad.u.dentry = dentry; | |
2999 | sid = cred_sid(cred); | |
5d226df4 AG |
3000 | isec = inode_security_rcu(inode, rcu); |
3001 | if (IS_ERR(isec)) | |
3002 | return PTR_ERR(isec); | |
bda0be7a N |
3003 | |
3004 | return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad, | |
3005 | rcu ? MAY_NOT_BLOCK : 0); | |
1da177e4 LT |
3006 | } |
3007 | ||
d4cf970d EP |
3008 | static noinline int audit_inode_permission(struct inode *inode, |
3009 | u32 perms, u32 audited, u32 denied, | |
626b9740 | 3010 | int result, |
d4cf970d | 3011 | unsigned flags) |
1da177e4 | 3012 | { |
b782e0a6 | 3013 | struct common_audit_data ad; |
33132849 | 3014 | struct inode_security_struct *isec = inode->i_security; |
d4cf970d EP |
3015 | int rc; |
3016 | ||
50c205f5 | 3017 | ad.type = LSM_AUDIT_DATA_INODE; |
d4cf970d EP |
3018 | ad.u.inode = inode; |
3019 | ||
3020 | rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms, | |
626b9740 | 3021 | audited, denied, result, &ad, flags); |
d4cf970d EP |
3022 | if (rc) |
3023 | return rc; | |
3024 | return 0; | |
3025 | } | |
3026 | ||
e74f71eb | 3027 | static int selinux_inode_permission(struct inode *inode, int mask) |
1da177e4 | 3028 | { |
88e67f3b | 3029 | const struct cred *cred = current_cred(); |
b782e0a6 EP |
3030 | u32 perms; |
3031 | bool from_access; | |
cf1dd1da | 3032 | unsigned flags = mask & MAY_NOT_BLOCK; |
2e334057 EP |
3033 | struct inode_security_struct *isec; |
3034 | u32 sid; | |
3035 | struct av_decision avd; | |
3036 | int rc, rc2; | |
3037 | u32 audited, denied; | |
1da177e4 | 3038 | |
b782e0a6 | 3039 | from_access = mask & MAY_ACCESS; |
d09ca739 EP |
3040 | mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
3041 | ||
b782e0a6 EP |
3042 | /* No permission to check. Existence test. */ |
3043 | if (!mask) | |
1da177e4 | 3044 | return 0; |
1da177e4 | 3045 | |
2e334057 | 3046 | validate_creds(cred); |
b782e0a6 | 3047 | |
2e334057 EP |
3048 | if (unlikely(IS_PRIVATE(inode))) |
3049 | return 0; | |
b782e0a6 EP |
3050 | |
3051 | perms = file_mask_to_av(inode->i_mode, mask); | |
3052 | ||
2e334057 | 3053 | sid = cred_sid(cred); |
5d226df4 AG |
3054 | isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK); |
3055 | if (IS_ERR(isec)) | |
3056 | return PTR_ERR(isec); | |
2e334057 EP |
3057 | |
3058 | rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd); | |
3059 | audited = avc_audit_required(perms, &avd, rc, | |
3060 | from_access ? FILE__AUDIT_ACCESS : 0, | |
3061 | &denied); | |
3062 | if (likely(!audited)) | |
3063 | return rc; | |
3064 | ||
626b9740 | 3065 | rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags); |
2e334057 EP |
3066 | if (rc2) |
3067 | return rc2; | |
3068 | return rc; | |
1da177e4 LT |
3069 | } |
3070 | ||
3071 | static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
3072 | { | |
88e67f3b | 3073 | const struct cred *cred = current_cred(); |
ccb54478 | 3074 | struct inode *inode = d_backing_inode(dentry); |
bc6a6008 | 3075 | unsigned int ia_valid = iattr->ia_valid; |
95dbf739 | 3076 | __u32 av = FILE__WRITE; |
1da177e4 | 3077 | |
bc6a6008 AW |
3078 | /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ |
3079 | if (ia_valid & ATTR_FORCE) { | |
3080 | ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | | |
3081 | ATTR_FORCE); | |
3082 | if (!ia_valid) | |
3083 | return 0; | |
3084 | } | |
1da177e4 | 3085 | |
bc6a6008 AW |
3086 | if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | |
3087 | ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) | |
2875fa00 | 3088 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
1da177e4 | 3089 | |
ccb54478 SS |
3090 | if (selinux_policycap_openperm && |
3091 | inode->i_sb->s_magic != SOCKFS_MAGIC && | |
3092 | (ia_valid & ATTR_SIZE) && | |
3093 | !(ia_valid & ATTR_FILE)) | |
95dbf739 EP |
3094 | av |= FILE__OPEN; |
3095 | ||
3096 | return dentry_has_perm(cred, dentry, av); | |
1da177e4 LT |
3097 | } |
3098 | ||
3f7036a0 | 3099 | static int selinux_inode_getattr(const struct path *path) |
1da177e4 | 3100 | { |
3f7036a0 | 3101 | return path_has_perm(current_cred(), path, FILE__GETATTR); |
1da177e4 LT |
3102 | } |
3103 | ||
8f0cfa52 | 3104 | static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) |
b5376771 | 3105 | { |
88e67f3b DH |
3106 | const struct cred *cred = current_cred(); |
3107 | ||
b5376771 SH |
3108 | if (!strncmp(name, XATTR_SECURITY_PREFIX, |
3109 | sizeof XATTR_SECURITY_PREFIX - 1)) { | |
3110 | if (!strcmp(name, XATTR_NAME_CAPS)) { | |
3111 | if (!capable(CAP_SETFCAP)) | |
3112 | return -EPERM; | |
3113 | } else if (!capable(CAP_SYS_ADMIN)) { | |
3114 | /* A different attribute in the security namespace. | |
3115 | Restrict to administrator. */ | |
3116 | return -EPERM; | |
3117 | } | |
3118 | } | |
3119 | ||
3120 | /* Not an attribute we recognize, so just check the | |
3121 | ordinary setattr permission. */ | |
2875fa00 | 3122 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
b5376771 SH |
3123 | } |
3124 | ||
db59000a SS |
3125 | static bool has_cap_mac_admin(bool audit) |
3126 | { | |
3127 | const struct cred *cred = current_cred(); | |
3128 | int cap_audit = audit ? SECURITY_CAP_AUDIT : SECURITY_CAP_NOAUDIT; | |
3129 | ||
3130 | if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, cap_audit)) | |
3131 | return false; | |
3132 | if (cred_has_capability(cred, CAP_MAC_ADMIN, cap_audit, true)) | |
3133 | return false; | |
3134 | return true; | |
3135 | } | |
3136 | ||
8f0cfa52 DH |
3137 | static int selinux_inode_setxattr(struct dentry *dentry, const char *name, |
3138 | const void *value, size_t size, int flags) | |
1da177e4 | 3139 | { |
c6f493d6 | 3140 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3141 | struct inode_security_struct *isec; |
1da177e4 | 3142 | struct superblock_security_struct *sbsec; |
2bf49690 | 3143 | struct common_audit_data ad; |
275bb41e | 3144 | u32 newsid, sid = current_sid(); |
1da177e4 LT |
3145 | int rc = 0; |
3146 | ||
b5376771 SH |
3147 | if (strcmp(name, XATTR_NAME_SELINUX)) |
3148 | return selinux_inode_setotherxattr(dentry, name); | |
1da177e4 | 3149 | |
33132849 | 3150 | sbsec = inode->i_sb->s_security; |
12f348b9 | 3151 | if (!(sbsec->flags & SBLABEL_MNT)) |
1da177e4 LT |
3152 | return -EOPNOTSUPP; |
3153 | ||
2e149670 | 3154 | if (!inode_owner_or_capable(inode)) |
1da177e4 LT |
3155 | return -EPERM; |
3156 | ||
50c205f5 | 3157 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 3158 | ad.u.dentry = dentry; |
1da177e4 | 3159 | |
20cdef8d | 3160 | isec = backing_inode_security(dentry); |
275bb41e | 3161 | rc = avc_has_perm(sid, isec->sid, isec->sclass, |
1da177e4 LT |
3162 | FILE__RELABELFROM, &ad); |
3163 | if (rc) | |
3164 | return rc; | |
3165 | ||
52a4c640 | 3166 | rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL); |
12b29f34 | 3167 | if (rc == -EINVAL) { |
db59000a | 3168 | if (!has_cap_mac_admin(true)) { |
d6ea83ec EP |
3169 | struct audit_buffer *ab; |
3170 | size_t audit_size; | |
3171 | const char *str; | |
3172 | ||
3173 | /* We strip a nul only if it is at the end, otherwise the | |
3174 | * context contains a nul and we should audit that */ | |
e3fea3f7 AV |
3175 | if (value) { |
3176 | str = value; | |
3177 | if (str[size - 1] == '\0') | |
3178 | audit_size = size - 1; | |
3179 | else | |
3180 | audit_size = size; | |
3181 | } else { | |
3182 | str = ""; | |
3183 | audit_size = 0; | |
3184 | } | |
d6ea83ec EP |
3185 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR); |
3186 | audit_log_format(ab, "op=setxattr invalid_context="); | |
3187 | audit_log_n_untrustedstring(ab, value, audit_size); | |
3188 | audit_log_end(ab); | |
3189 | ||
12b29f34 | 3190 | return rc; |
d6ea83ec | 3191 | } |
12b29f34 SS |
3192 | rc = security_context_to_sid_force(value, size, &newsid); |
3193 | } | |
1da177e4 LT |
3194 | if (rc) |
3195 | return rc; | |
3196 | ||
275bb41e | 3197 | rc = avc_has_perm(sid, newsid, isec->sclass, |
1da177e4 LT |
3198 | FILE__RELABELTO, &ad); |
3199 | if (rc) | |
3200 | return rc; | |
3201 | ||
275bb41e | 3202 | rc = security_validate_transition(isec->sid, newsid, sid, |
828dfe1d | 3203 | isec->sclass); |
1da177e4 LT |
3204 | if (rc) |
3205 | return rc; | |
3206 | ||
3207 | return avc_has_perm(newsid, | |
3208 | sbsec->sid, | |
3209 | SECCLASS_FILESYSTEM, | |
3210 | FILESYSTEM__ASSOCIATE, | |
3211 | &ad); | |
3212 | } | |
3213 | ||
8f0cfa52 | 3214 | static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, |
f5269710 | 3215 | const void *value, size_t size, |
8f0cfa52 | 3216 | int flags) |
1da177e4 | 3217 | { |
c6f493d6 | 3218 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3219 | struct inode_security_struct *isec; |
1da177e4 LT |
3220 | u32 newsid; |
3221 | int rc; | |
3222 | ||
3223 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
3224 | /* Not an attribute we recognize, so nothing to do. */ | |
3225 | return; | |
3226 | } | |
3227 | ||
12b29f34 | 3228 | rc = security_context_to_sid_force(value, size, &newsid); |
1da177e4 | 3229 | if (rc) { |
12b29f34 SS |
3230 | printk(KERN_ERR "SELinux: unable to map context to SID" |
3231 | "for (%s, %lu), rc=%d\n", | |
3232 | inode->i_sb->s_id, inode->i_ino, -rc); | |
1da177e4 LT |
3233 | return; |
3234 | } | |
3235 | ||
20cdef8d | 3236 | isec = backing_inode_security(dentry); |
9287aed2 | 3237 | spin_lock(&isec->lock); |
aa9c2669 | 3238 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3239 | isec->sid = newsid; |
6f3be9f5 | 3240 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3241 | spin_unlock(&isec->lock); |
aa9c2669 | 3242 | |
1da177e4 LT |
3243 | return; |
3244 | } | |
3245 | ||
8f0cfa52 | 3246 | static int selinux_inode_getxattr(struct dentry *dentry, const char *name) |
1da177e4 | 3247 | { |
88e67f3b DH |
3248 | const struct cred *cred = current_cred(); |
3249 | ||
2875fa00 | 3250 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3251 | } |
3252 | ||
828dfe1d | 3253 | static int selinux_inode_listxattr(struct dentry *dentry) |
1da177e4 | 3254 | { |
88e67f3b DH |
3255 | const struct cred *cred = current_cred(); |
3256 | ||
2875fa00 | 3257 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3258 | } |
3259 | ||
8f0cfa52 | 3260 | static int selinux_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 3261 | { |
b5376771 SH |
3262 | if (strcmp(name, XATTR_NAME_SELINUX)) |
3263 | return selinux_inode_setotherxattr(dentry, name); | |
1da177e4 LT |
3264 | |
3265 | /* No one is allowed to remove a SELinux security label. | |
3266 | You can change the label, but all data must be labeled. */ | |
3267 | return -EACCES; | |
3268 | } | |
3269 | ||
d381d8a9 | 3270 | /* |
abc69bb6 | 3271 | * Copy the inode security context value to the user. |
d381d8a9 JM |
3272 | * |
3273 | * Permission check is handled by selinux_inode_getxattr hook. | |
3274 | */ | |
ea861dfd | 3275 | static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc) |
1da177e4 | 3276 | { |
42492594 DQ |
3277 | u32 size; |
3278 | int error; | |
3279 | char *context = NULL; | |
20cdef8d | 3280 | struct inode_security_struct *isec; |
d381d8a9 | 3281 | |
8c8570fb DK |
3282 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) |
3283 | return -EOPNOTSUPP; | |
d381d8a9 | 3284 | |
abc69bb6 SS |
3285 | /* |
3286 | * If the caller has CAP_MAC_ADMIN, then get the raw context | |
3287 | * value even if it is not defined by current policy; otherwise, | |
3288 | * use the in-core value under current policy. | |
3289 | * Use the non-auditing forms of the permission checks since | |
3290 | * getxattr may be called by unprivileged processes commonly | |
3291 | * and lack of permission just means that we fall back to the | |
3292 | * in-core context value, not a denial. | |
3293 | */ | |
20cdef8d | 3294 | isec = inode_security(inode); |
db59000a | 3295 | if (has_cap_mac_admin(false)) |
abc69bb6 SS |
3296 | error = security_sid_to_context_force(isec->sid, &context, |
3297 | &size); | |
3298 | else | |
3299 | error = security_sid_to_context(isec->sid, &context, &size); | |
42492594 DQ |
3300 | if (error) |
3301 | return error; | |
3302 | error = size; | |
3303 | if (alloc) { | |
3304 | *buffer = context; | |
3305 | goto out_nofree; | |
3306 | } | |
3307 | kfree(context); | |
3308 | out_nofree: | |
3309 | return error; | |
1da177e4 LT |
3310 | } |
3311 | ||
3312 | static int selinux_inode_setsecurity(struct inode *inode, const char *name, | |
828dfe1d | 3313 | const void *value, size_t size, int flags) |
1da177e4 | 3314 | { |
2c97165b | 3315 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
1da177e4 LT |
3316 | u32 newsid; |
3317 | int rc; | |
3318 | ||
3319 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) | |
3320 | return -EOPNOTSUPP; | |
3321 | ||
3322 | if (!value || !size) | |
3323 | return -EACCES; | |
3324 | ||
20ba96ae | 3325 | rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL); |
1da177e4 LT |
3326 | if (rc) |
3327 | return rc; | |
3328 | ||
9287aed2 | 3329 | spin_lock(&isec->lock); |
aa9c2669 | 3330 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3331 | isec->sid = newsid; |
6f3be9f5 | 3332 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3333 | spin_unlock(&isec->lock); |
1da177e4 LT |
3334 | return 0; |
3335 | } | |
3336 | ||
3337 | static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) | |
3338 | { | |
3339 | const int len = sizeof(XATTR_NAME_SELINUX); | |
3340 | if (buffer && len <= buffer_size) | |
3341 | memcpy(buffer, XATTR_NAME_SELINUX, len); | |
3342 | return len; | |
3343 | } | |
3344 | ||
d6335d77 | 3345 | static void selinux_inode_getsecid(struct inode *inode, u32 *secid) |
713a04ae | 3346 | { |
e817c2f3 | 3347 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
713a04ae AD |
3348 | *secid = isec->sid; |
3349 | } | |
3350 | ||
56909eb3 VG |
3351 | static int selinux_inode_copy_up(struct dentry *src, struct cred **new) |
3352 | { | |
3353 | u32 sid; | |
3354 | struct task_security_struct *tsec; | |
3355 | struct cred *new_creds = *new; | |
3356 | ||
3357 | if (new_creds == NULL) { | |
3358 | new_creds = prepare_creds(); | |
3359 | if (!new_creds) | |
3360 | return -ENOMEM; | |
3361 | } | |
3362 | ||
98738d70 | 3363 | tsec = selinux_cred(new_creds); |
56909eb3 VG |
3364 | /* Get label from overlay inode and set it in create_sid */ |
3365 | selinux_inode_getsecid(d_inode(src), &sid); | |
3366 | tsec->create_sid = sid; | |
3367 | *new = new_creds; | |
3368 | return 0; | |
3369 | } | |
3370 | ||
19472b69 VG |
3371 | static int selinux_inode_copy_up_xattr(const char *name) |
3372 | { | |
3373 | /* The copy_up hook above sets the initial context on an inode, but we | |
3374 | * don't then want to overwrite it by blindly copying all the lower | |
3375 | * xattrs up. Instead, we have to filter out SELinux-related xattrs. | |
3376 | */ | |
3377 | if (strcmp(name, XATTR_NAME_SELINUX) == 0) | |
3378 | return 1; /* Discard */ | |
3379 | /* | |
3380 | * Any other attribute apart from SELINUX is not claimed, supported | |
3381 | * by selinux. | |
3382 | */ | |
3383 | return -EOPNOTSUPP; | |
3384 | } | |
3385 | ||
1da177e4 LT |
3386 | /* file security operations */ |
3387 | ||
788e7dd4 | 3388 | static int selinux_revalidate_file_permission(struct file *file, int mask) |
1da177e4 | 3389 | { |
88e67f3b | 3390 | const struct cred *cred = current_cred(); |
496ad9aa | 3391 | struct inode *inode = file_inode(file); |
1da177e4 | 3392 | |
1da177e4 LT |
3393 | /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ |
3394 | if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) | |
3395 | mask |= MAY_APPEND; | |
3396 | ||
389fb800 PM |
3397 | return file_has_perm(cred, file, |
3398 | file_mask_to_av(inode->i_mode, mask)); | |
1da177e4 LT |
3399 | } |
3400 | ||
788e7dd4 YN |
3401 | static int selinux_file_permission(struct file *file, int mask) |
3402 | { | |
496ad9aa | 3403 | struct inode *inode = file_inode(file); |
004c5200 | 3404 | struct file_security_struct *fsec = selinux_file(file); |
b197367e | 3405 | struct inode_security_struct *isec; |
20dda18b SS |
3406 | u32 sid = current_sid(); |
3407 | ||
389fb800 | 3408 | if (!mask) |
788e7dd4 YN |
3409 | /* No permission to check. Existence test. */ |
3410 | return 0; | |
788e7dd4 | 3411 | |
b197367e | 3412 | isec = inode_security(inode); |
20dda18b SS |
3413 | if (sid == fsec->sid && fsec->isid == isec->sid && |
3414 | fsec->pseqno == avc_policy_seqno()) | |
83d49856 | 3415 | /* No change since file_open check. */ |
20dda18b SS |
3416 | return 0; |
3417 | ||
788e7dd4 YN |
3418 | return selinux_revalidate_file_permission(file, mask); |
3419 | } | |
3420 | ||
1da177e4 LT |
3421 | static int selinux_file_alloc_security(struct file *file) |
3422 | { | |
3423 | return file_alloc_security(file); | |
3424 | } | |
3425 | ||
fa1aa143 JVS |
3426 | /* |
3427 | * Check whether a task has the ioctl permission and cmd | |
3428 | * operation to an inode. | |
3429 | */ | |
1d2a168a | 3430 | static int ioctl_has_perm(const struct cred *cred, struct file *file, |
fa1aa143 JVS |
3431 | u32 requested, u16 cmd) |
3432 | { | |
3433 | struct common_audit_data ad; | |
004c5200 | 3434 | struct file_security_struct *fsec = selinux_file(file); |
fa1aa143 | 3435 | struct inode *inode = file_inode(file); |
20cdef8d | 3436 | struct inode_security_struct *isec; |
fa1aa143 JVS |
3437 | struct lsm_ioctlop_audit ioctl; |
3438 | u32 ssid = cred_sid(cred); | |
3439 | int rc; | |
3440 | u8 driver = cmd >> 8; | |
3441 | u8 xperm = cmd & 0xff; | |
3442 | ||
3443 | ad.type = LSM_AUDIT_DATA_IOCTL_OP; | |
3444 | ad.u.op = &ioctl; | |
3445 | ad.u.op->cmd = cmd; | |
3446 | ad.u.op->path = file->f_path; | |
3447 | ||
3448 | if (ssid != fsec->sid) { | |
3449 | rc = avc_has_perm(ssid, fsec->sid, | |
3450 | SECCLASS_FD, | |
3451 | FD__USE, | |
3452 | &ad); | |
3453 | if (rc) | |
3454 | goto out; | |
3455 | } | |
3456 | ||
3457 | if (unlikely(IS_PRIVATE(inode))) | |
3458 | return 0; | |
3459 | ||
20cdef8d | 3460 | isec = inode_security(inode); |
fa1aa143 JVS |
3461 | rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass, |
3462 | requested, driver, xperm, &ad); | |
3463 | out: | |
3464 | return rc; | |
3465 | } | |
3466 | ||
1da177e4 LT |
3467 | static int selinux_file_ioctl(struct file *file, unsigned int cmd, |
3468 | unsigned long arg) | |
3469 | { | |
88e67f3b | 3470 | const struct cred *cred = current_cred(); |
0b24dcb7 | 3471 | int error = 0; |
1da177e4 | 3472 | |
0b24dcb7 EP |
3473 | switch (cmd) { |
3474 | case FIONREAD: | |
3475 | /* fall through */ | |
3476 | case FIBMAP: | |
3477 | /* fall through */ | |
3478 | case FIGETBSZ: | |
3479 | /* fall through */ | |
2f99c369 | 3480 | case FS_IOC_GETFLAGS: |
0b24dcb7 | 3481 | /* fall through */ |
2f99c369 | 3482 | case FS_IOC_GETVERSION: |
0b24dcb7 EP |
3483 | error = file_has_perm(cred, file, FILE__GETATTR); |
3484 | break; | |
1da177e4 | 3485 | |
2f99c369 | 3486 | case FS_IOC_SETFLAGS: |
0b24dcb7 | 3487 | /* fall through */ |
2f99c369 | 3488 | case FS_IOC_SETVERSION: |
0b24dcb7 EP |
3489 | error = file_has_perm(cred, file, FILE__SETATTR); |
3490 | break; | |
3491 | ||
3492 | /* sys_ioctl() checks */ | |
3493 | case FIONBIO: | |
3494 | /* fall through */ | |
3495 | case FIOASYNC: | |
3496 | error = file_has_perm(cred, file, 0); | |
3497 | break; | |
1da177e4 | 3498 | |
0b24dcb7 EP |
3499 | case KDSKBENT: |
3500 | case KDSKBSENT: | |
6a9de491 | 3501 | error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, |
8e4ff6f2 | 3502 | SECURITY_CAP_AUDIT, true); |
0b24dcb7 EP |
3503 | break; |
3504 | ||
3505 | /* default case assumes that the command will go | |
3506 | * to the file's ioctl() function. | |
3507 | */ | |
3508 | default: | |
fa1aa143 | 3509 | error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); |
0b24dcb7 EP |
3510 | } |
3511 | return error; | |
1da177e4 LT |
3512 | } |
3513 | ||
fcaaade1 SS |
3514 | static int default_noexec; |
3515 | ||
1da177e4 LT |
3516 | static int file_map_prot_check(struct file *file, unsigned long prot, int shared) |
3517 | { | |
88e67f3b | 3518 | const struct cred *cred = current_cred(); |
be0554c9 | 3519 | u32 sid = cred_sid(cred); |
d84f4f99 | 3520 | int rc = 0; |
88e67f3b | 3521 | |
fcaaade1 | 3522 | if (default_noexec && |
892e8cac SS |
3523 | (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) || |
3524 | (!shared && (prot & PROT_WRITE)))) { | |
1da177e4 LT |
3525 | /* |
3526 | * We are making executable an anonymous mapping or a | |
3527 | * private file mapping that will also be writable. | |
3528 | * This has an additional check. | |
3529 | */ | |
be0554c9 SS |
3530 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3531 | PROCESS__EXECMEM, NULL); | |
1da177e4 | 3532 | if (rc) |
d84f4f99 | 3533 | goto error; |
1da177e4 | 3534 | } |
1da177e4 LT |
3535 | |
3536 | if (file) { | |
3537 | /* read access is always possible with a mapping */ | |
3538 | u32 av = FILE__READ; | |
3539 | ||
3540 | /* write access only matters if the mapping is shared */ | |
3541 | if (shared && (prot & PROT_WRITE)) | |
3542 | av |= FILE__WRITE; | |
3543 | ||
3544 | if (prot & PROT_EXEC) | |
3545 | av |= FILE__EXECUTE; | |
3546 | ||
88e67f3b | 3547 | return file_has_perm(cred, file, av); |
1da177e4 | 3548 | } |
d84f4f99 DH |
3549 | |
3550 | error: | |
3551 | return rc; | |
1da177e4 LT |
3552 | } |
3553 | ||
e5467859 | 3554 | static int selinux_mmap_addr(unsigned long addr) |
1da177e4 | 3555 | { |
b1d9e6b0 | 3556 | int rc = 0; |
1da177e4 | 3557 | |
a2551df7 | 3558 | if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { |
98883bfd | 3559 | u32 sid = current_sid(); |
ed032189 EP |
3560 | rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, |
3561 | MEMPROTECT__MMAP_ZERO, NULL); | |
84336d1a EP |
3562 | } |
3563 | ||
98883bfd | 3564 | return rc; |
e5467859 | 3565 | } |
1da177e4 | 3566 | |
e5467859 AV |
3567 | static int selinux_mmap_file(struct file *file, unsigned long reqprot, |
3568 | unsigned long prot, unsigned long flags) | |
3569 | { | |
3ba4bf5f SS |
3570 | struct common_audit_data ad; |
3571 | int rc; | |
3572 | ||
3573 | if (file) { | |
3574 | ad.type = LSM_AUDIT_DATA_FILE; | |
3575 | ad.u.file = file; | |
3576 | rc = inode_has_perm(current_cred(), file_inode(file), | |
3577 | FILE__MAP, &ad); | |
3578 | if (rc) | |
3579 | return rc; | |
3580 | } | |
3581 | ||
1da177e4 LT |
3582 | if (selinux_checkreqprot) |
3583 | prot = reqprot; | |
3584 | ||
3585 | return file_map_prot_check(file, prot, | |
3586 | (flags & MAP_TYPE) == MAP_SHARED); | |
3587 | } | |
3588 | ||
3589 | static int selinux_file_mprotect(struct vm_area_struct *vma, | |
3590 | unsigned long reqprot, | |
3591 | unsigned long prot) | |
3592 | { | |
88e67f3b | 3593 | const struct cred *cred = current_cred(); |
be0554c9 | 3594 | u32 sid = cred_sid(cred); |
1da177e4 LT |
3595 | |
3596 | if (selinux_checkreqprot) | |
3597 | prot = reqprot; | |
3598 | ||
fcaaade1 SS |
3599 | if (default_noexec && |
3600 | (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { | |
d541bbee | 3601 | int rc = 0; |
db4c9641 SS |
3602 | if (vma->vm_start >= vma->vm_mm->start_brk && |
3603 | vma->vm_end <= vma->vm_mm->brk) { | |
be0554c9 SS |
3604 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3605 | PROCESS__EXECHEAP, NULL); | |
db4c9641 | 3606 | } else if (!vma->vm_file && |
c2316dbf SS |
3607 | ((vma->vm_start <= vma->vm_mm->start_stack && |
3608 | vma->vm_end >= vma->vm_mm->start_stack) || | |
d17af505 | 3609 | vma_is_stack_for_current(vma))) { |
be0554c9 SS |
3610 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3611 | PROCESS__EXECSTACK, NULL); | |
db4c9641 SS |
3612 | } else if (vma->vm_file && vma->anon_vma) { |
3613 | /* | |
3614 | * We are making executable a file mapping that has | |
3615 | * had some COW done. Since pages might have been | |
3616 | * written, check ability to execute the possibly | |
3617 | * modified content. This typically should only | |
3618 | * occur for text relocations. | |
3619 | */ | |
d84f4f99 | 3620 | rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); |
db4c9641 | 3621 | } |