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Commit | Line | Data |
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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 | * | |
7efbb60b | 6 | * Authors: Stephen Smalley, <sds@tycho.nsa.gov> |
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 | ||
e18b890b | 131 | static struct kmem_cache *sel_inode_cache; |
63205654 | 132 | static struct kmem_cache *file_security_cache; |
7cae7e26 | 133 | |
d621d35e PM |
134 | /** |
135 | * selinux_secmark_enabled - Check to see if SECMARK is currently enabled | |
136 | * | |
137 | * Description: | |
138 | * This function checks the SECMARK reference counter to see if any SECMARK | |
139 | * targets are currently configured, if the reference counter is greater than | |
140 | * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is | |
2be4d74f CP |
141 | * enabled, false (0) if SECMARK is disabled. If the always_check_network |
142 | * policy capability is enabled, SECMARK is always considered enabled. | |
d621d35e PM |
143 | * |
144 | */ | |
145 | static int selinux_secmark_enabled(void) | |
146 | { | |
2be4d74f CP |
147 | return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount)); |
148 | } | |
149 | ||
150 | /** | |
151 | * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled | |
152 | * | |
153 | * Description: | |
154 | * This function checks if NetLabel or labeled IPSEC is enabled. Returns true | |
155 | * (1) if any are enabled or false (0) if neither are enabled. If the | |
156 | * always_check_network policy capability is enabled, peer labeling | |
157 | * is always considered enabled. | |
158 | * | |
159 | */ | |
160 | static int selinux_peerlbl_enabled(void) | |
161 | { | |
162 | return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled()); | |
d621d35e PM |
163 | } |
164 | ||
615e51fd PM |
165 | static int selinux_netcache_avc_callback(u32 event) |
166 | { | |
167 | if (event == AVC_CALLBACK_RESET) { | |
168 | sel_netif_flush(); | |
169 | sel_netnode_flush(); | |
170 | sel_netport_flush(); | |
171 | synchronize_net(); | |
172 | } | |
173 | return 0; | |
174 | } | |
175 | ||
8f408ab6 DJ |
176 | static int selinux_lsm_notifier_avc_callback(u32 event) |
177 | { | |
409dcf31 DJ |
178 | if (event == AVC_CALLBACK_RESET) { |
179 | sel_ib_pkey_flush(); | |
8f408ab6 | 180 | call_lsm_notifier(LSM_POLICY_CHANGE, NULL); |
409dcf31 | 181 | } |
8f408ab6 DJ |
182 | |
183 | return 0; | |
184 | } | |
185 | ||
d84f4f99 DH |
186 | /* |
187 | * initialise the security for the init task | |
188 | */ | |
189 | static void cred_init_security(void) | |
1da177e4 | 190 | { |
3b11a1de | 191 | struct cred *cred = (struct cred *) current->real_cred; |
1da177e4 LT |
192 | struct task_security_struct *tsec; |
193 | ||
89d155ef | 194 | tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); |
1da177e4 | 195 | if (!tsec) |
d84f4f99 | 196 | panic("SELinux: Failed to initialize initial task.\n"); |
1da177e4 | 197 | |
d84f4f99 | 198 | tsec->osid = tsec->sid = SECINITSID_KERNEL; |
f1752eec | 199 | cred->security = tsec; |
1da177e4 LT |
200 | } |
201 | ||
88e67f3b DH |
202 | /* |
203 | * get the security ID of a set of credentials | |
204 | */ | |
205 | static inline u32 cred_sid(const struct cred *cred) | |
206 | { | |
207 | const struct task_security_struct *tsec; | |
208 | ||
209 | tsec = cred->security; | |
210 | return tsec->sid; | |
211 | } | |
212 | ||
275bb41e | 213 | /* |
3b11a1de | 214 | * get the objective security ID of a task |
275bb41e DH |
215 | */ |
216 | static inline u32 task_sid(const struct task_struct *task) | |
217 | { | |
275bb41e DH |
218 | u32 sid; |
219 | ||
220 | rcu_read_lock(); | |
88e67f3b | 221 | sid = cred_sid(__task_cred(task)); |
275bb41e DH |
222 | rcu_read_unlock(); |
223 | return sid; | |
224 | } | |
225 | ||
88e67f3b DH |
226 | /* Allocate and free functions for each kind of security blob. */ |
227 | ||
1da177e4 LT |
228 | static int inode_alloc_security(struct inode *inode) |
229 | { | |
1da177e4 | 230 | struct inode_security_struct *isec; |
275bb41e | 231 | u32 sid = current_sid(); |
1da177e4 | 232 | |
a02fe132 | 233 | isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); |
1da177e4 LT |
234 | if (!isec) |
235 | return -ENOMEM; | |
236 | ||
9287aed2 | 237 | spin_lock_init(&isec->lock); |
1da177e4 | 238 | INIT_LIST_HEAD(&isec->list); |
1da177e4 LT |
239 | isec->inode = inode; |
240 | isec->sid = SECINITSID_UNLABELED; | |
241 | isec->sclass = SECCLASS_FILE; | |
275bb41e | 242 | isec->task_sid = sid; |
42059112 | 243 | isec->initialized = LABEL_INVALID; |
1da177e4 LT |
244 | inode->i_security = isec; |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
5d226df4 AG |
249 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); |
250 | ||
251 | /* | |
252 | * Try reloading inode security labels that have been marked as invalid. The | |
253 | * @may_sleep parameter indicates when sleeping and thus reloading labels is | |
42059112 | 254 | * allowed; when set to false, returns -ECHILD when the label is |
5d226df4 AG |
255 | * invalid. The @opt_dentry parameter should be set to a dentry of the inode; |
256 | * when no dentry is available, set it to NULL instead. | |
257 | */ | |
258 | static int __inode_security_revalidate(struct inode *inode, | |
259 | struct dentry *opt_dentry, | |
260 | bool may_sleep) | |
261 | { | |
262 | struct inode_security_struct *isec = inode->i_security; | |
263 | ||
264 | might_sleep_if(may_sleep); | |
265 | ||
1ac42476 | 266 | if (ss_initialized && isec->initialized != LABEL_INITIALIZED) { |
5d226df4 AG |
267 | if (!may_sleep) |
268 | return -ECHILD; | |
269 | ||
270 | /* | |
271 | * Try reloading the inode security label. This will fail if | |
272 | * @opt_dentry is NULL and no dentry for this inode can be | |
273 | * found; in that case, continue using the old label. | |
274 | */ | |
275 | inode_doinit_with_dentry(inode, opt_dentry); | |
276 | } | |
277 | return 0; | |
278 | } | |
279 | ||
5d226df4 AG |
280 | static struct inode_security_struct *inode_security_novalidate(struct inode *inode) |
281 | { | |
282 | return inode->i_security; | |
283 | } | |
284 | ||
285 | static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu) | |
286 | { | |
287 | int error; | |
288 | ||
289 | error = __inode_security_revalidate(inode, NULL, !rcu); | |
290 | if (error) | |
291 | return ERR_PTR(error); | |
292 | return inode->i_security; | |
293 | } | |
294 | ||
83da53c5 AG |
295 | /* |
296 | * Get the security label of an inode. | |
297 | */ | |
298 | static struct inode_security_struct *inode_security(struct inode *inode) | |
299 | { | |
5d226df4 | 300 | __inode_security_revalidate(inode, NULL, true); |
83da53c5 AG |
301 | return inode->i_security; |
302 | } | |
303 | ||
2c97165b PM |
304 | static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry) |
305 | { | |
306 | struct inode *inode = d_backing_inode(dentry); | |
307 | ||
308 | return inode->i_security; | |
309 | } | |
310 | ||
83da53c5 AG |
311 | /* |
312 | * Get the security label of a dentry's backing inode. | |
313 | */ | |
314 | static struct inode_security_struct *backing_inode_security(struct dentry *dentry) | |
315 | { | |
316 | struct inode *inode = d_backing_inode(dentry); | |
317 | ||
5d226df4 | 318 | __inode_security_revalidate(inode, dentry, true); |
83da53c5 AG |
319 | return inode->i_security; |
320 | } | |
321 | ||
3dc91d43 SR |
322 | static void inode_free_rcu(struct rcu_head *head) |
323 | { | |
324 | struct inode_security_struct *isec; | |
325 | ||
326 | isec = container_of(head, struct inode_security_struct, rcu); | |
327 | kmem_cache_free(sel_inode_cache, isec); | |
328 | } | |
329 | ||
1da177e4 LT |
330 | static void inode_free_security(struct inode *inode) |
331 | { | |
332 | struct inode_security_struct *isec = inode->i_security; | |
333 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; | |
334 | ||
9629d04a WL |
335 | /* |
336 | * As not all inode security structures are in a list, we check for | |
337 | * empty list outside of the lock to make sure that we won't waste | |
338 | * time taking a lock doing nothing. | |
339 | * | |
340 | * The list_del_init() function can be safely called more than once. | |
341 | * It should not be possible for this function to be called with | |
342 | * concurrent list_add(), but for better safety against future changes | |
343 | * in the code, we use list_empty_careful() here. | |
344 | */ | |
345 | if (!list_empty_careful(&isec->list)) { | |
346 | spin_lock(&sbsec->isec_lock); | |
1da177e4 | 347 | list_del_init(&isec->list); |
9629d04a WL |
348 | spin_unlock(&sbsec->isec_lock); |
349 | } | |
1da177e4 | 350 | |
3dc91d43 SR |
351 | /* |
352 | * The inode may still be referenced in a path walk and | |
353 | * a call to selinux_inode_permission() can be made | |
354 | * after inode_free_security() is called. Ideally, the VFS | |
355 | * wouldn't do this, but fixing that is a much harder | |
356 | * job. For now, simply free the i_security via RCU, and | |
357 | * leave the current inode->i_security pointer intact. | |
358 | * The inode will be freed after the RCU grace period too. | |
359 | */ | |
360 | call_rcu(&isec->rcu, inode_free_rcu); | |
1da177e4 LT |
361 | } |
362 | ||
363 | static int file_alloc_security(struct file *file) | |
364 | { | |
1da177e4 | 365 | struct file_security_struct *fsec; |
275bb41e | 366 | u32 sid = current_sid(); |
1da177e4 | 367 | |
63205654 | 368 | fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL); |
1da177e4 LT |
369 | if (!fsec) |
370 | return -ENOMEM; | |
371 | ||
275bb41e DH |
372 | fsec->sid = sid; |
373 | fsec->fown_sid = sid; | |
1da177e4 LT |
374 | file->f_security = fsec; |
375 | ||
376 | return 0; | |
377 | } | |
378 | ||
379 | static void file_free_security(struct file *file) | |
380 | { | |
381 | struct file_security_struct *fsec = file->f_security; | |
1da177e4 | 382 | file->f_security = NULL; |
63205654 | 383 | kmem_cache_free(file_security_cache, fsec); |
1da177e4 LT |
384 | } |
385 | ||
386 | static int superblock_alloc_security(struct super_block *sb) | |
387 | { | |
388 | struct superblock_security_struct *sbsec; | |
389 | ||
89d155ef | 390 | sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); |
1da177e4 LT |
391 | if (!sbsec) |
392 | return -ENOMEM; | |
393 | ||
bc7e982b | 394 | mutex_init(&sbsec->lock); |
1da177e4 LT |
395 | INIT_LIST_HEAD(&sbsec->isec_head); |
396 | spin_lock_init(&sbsec->isec_lock); | |
1da177e4 LT |
397 | sbsec->sb = sb; |
398 | sbsec->sid = SECINITSID_UNLABELED; | |
399 | sbsec->def_sid = SECINITSID_FILE; | |
c312feb2 | 400 | sbsec->mntpoint_sid = SECINITSID_UNLABELED; |
1da177e4 LT |
401 | sb->s_security = sbsec; |
402 | ||
403 | return 0; | |
404 | } | |
405 | ||
406 | static void superblock_free_security(struct super_block *sb) | |
407 | { | |
408 | struct superblock_security_struct *sbsec = sb->s_security; | |
1da177e4 LT |
409 | sb->s_security = NULL; |
410 | kfree(sbsec); | |
411 | } | |
412 | ||
1da177e4 LT |
413 | static inline int inode_doinit(struct inode *inode) |
414 | { | |
415 | return inode_doinit_with_dentry(inode, NULL); | |
416 | } | |
417 | ||
418 | enum { | |
31e87930 | 419 | Opt_error = -1, |
1da177e4 LT |
420 | Opt_context = 1, |
421 | Opt_fscontext = 2, | |
c9180a57 EP |
422 | Opt_defcontext = 3, |
423 | Opt_rootcontext = 4, | |
11689d47 | 424 | Opt_labelsupport = 5, |
d355987f | 425 | Opt_nextmntopt = 6, |
1da177e4 LT |
426 | }; |
427 | ||
d355987f EP |
428 | #define NUM_SEL_MNT_OPTS (Opt_nextmntopt - 1) |
429 | ||
a447c093 | 430 | static const match_table_t tokens = { |
832cbd9a EP |
431 | {Opt_context, CONTEXT_STR "%s"}, |
432 | {Opt_fscontext, FSCONTEXT_STR "%s"}, | |
433 | {Opt_defcontext, DEFCONTEXT_STR "%s"}, | |
434 | {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, | |
11689d47 | 435 | {Opt_labelsupport, LABELSUPP_STR}, |
31e87930 | 436 | {Opt_error, NULL}, |
1da177e4 LT |
437 | }; |
438 | ||
439 | #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" | |
440 | ||
c312feb2 EP |
441 | static int may_context_mount_sb_relabel(u32 sid, |
442 | struct superblock_security_struct *sbsec, | |
275bb41e | 443 | const struct cred *cred) |
c312feb2 | 444 | { |
275bb41e | 445 | const struct task_security_struct *tsec = cred->security; |
c312feb2 EP |
446 | int rc; |
447 | ||
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(tsec->sid, sid, SECCLASS_FILESYSTEM, | |
454 | FILESYSTEM__RELABELTO, NULL); | |
455 | return rc; | |
456 | } | |
457 | ||
0808925e EP |
458 | static int may_context_mount_inode_relabel(u32 sid, |
459 | struct superblock_security_struct *sbsec, | |
275bb41e | 460 | const struct cred *cred) |
0808925e | 461 | { |
275bb41e | 462 | const struct task_security_struct *tsec = cred->security; |
0808925e EP |
463 | int rc; |
464 | rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
465 | FILESYSTEM__RELABELFROM, NULL); | |
466 | if (rc) | |
467 | return rc; | |
468 | ||
469 | rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
470 | FILESYSTEM__ASSOCIATE, NULL); | |
471 | return rc; | |
472 | } | |
473 | ||
b43e725d EP |
474 | static int selinux_is_sblabel_mnt(struct super_block *sb) |
475 | { | |
476 | struct superblock_security_struct *sbsec = sb->s_security; | |
477 | ||
d5f3a5f6 MS |
478 | return sbsec->behavior == SECURITY_FS_USE_XATTR || |
479 | sbsec->behavior == SECURITY_FS_USE_TRANS || | |
480 | sbsec->behavior == SECURITY_FS_USE_TASK || | |
9fc2b4b4 | 481 | sbsec->behavior == SECURITY_FS_USE_NATIVE || |
d5f3a5f6 MS |
482 | /* Special handling. Genfs but also in-core setxattr handler */ |
483 | !strcmp(sb->s_type->name, "sysfs") || | |
484 | !strcmp(sb->s_type->name, "pstore") || | |
485 | !strcmp(sb->s_type->name, "debugfs") || | |
a2c7c6fb | 486 | !strcmp(sb->s_type->name, "tracefs") || |
2651225b SS |
487 | !strcmp(sb->s_type->name, "rootfs") || |
488 | (selinux_policycap_cgroupseclabel && | |
489 | (!strcmp(sb->s_type->name, "cgroup") || | |
490 | !strcmp(sb->s_type->name, "cgroup2"))); | |
b43e725d EP |
491 | } |
492 | ||
c9180a57 | 493 | static int sb_finish_set_opts(struct super_block *sb) |
1da177e4 | 494 | { |
1da177e4 | 495 | struct superblock_security_struct *sbsec = sb->s_security; |
c9180a57 | 496 | struct dentry *root = sb->s_root; |
c6f493d6 | 497 | struct inode *root_inode = d_backing_inode(root); |
c9180a57 | 498 | int rc = 0; |
1da177e4 | 499 | |
c9180a57 EP |
500 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { |
501 | /* Make sure that the xattr handler exists and that no | |
502 | error other than -ENODATA is returned by getxattr on | |
503 | the root directory. -ENODATA is ok, as this may be | |
504 | the first boot of the SELinux kernel before we have | |
505 | assigned xattr values to the filesystem. */ | |
5d6c3191 | 506 | if (!(root_inode->i_opflags & IOP_XATTR)) { |
29b1deb2 LT |
507 | printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " |
508 | "xattr support\n", sb->s_id, sb->s_type->name); | |
c9180a57 EP |
509 | rc = -EOPNOTSUPP; |
510 | goto out; | |
511 | } | |
5d6c3191 AG |
512 | |
513 | rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0); | |
c9180a57 EP |
514 | if (rc < 0 && rc != -ENODATA) { |
515 | if (rc == -EOPNOTSUPP) | |
516 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
29b1deb2 LT |
517 | "%s) has no security xattr handler\n", |
518 | sb->s_id, sb->s_type->name); | |
c9180a57 EP |
519 | else |
520 | printk(KERN_WARNING "SELinux: (dev %s, type " | |
29b1deb2 LT |
521 | "%s) getxattr errno %d\n", sb->s_id, |
522 | sb->s_type->name, -rc); | |
c9180a57 EP |
523 | goto out; |
524 | } | |
525 | } | |
1da177e4 | 526 | |
eadcabc6 | 527 | sbsec->flags |= SE_SBINITIALIZED; |
0b4d3452 SM |
528 | |
529 | /* | |
530 | * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply | |
531 | * leave the flag untouched because sb_clone_mnt_opts might be handing | |
532 | * us a superblock that needs the flag to be cleared. | |
533 | */ | |
b43e725d | 534 | if (selinux_is_sblabel_mnt(sb)) |
12f348b9 | 535 | sbsec->flags |= SBLABEL_MNT; |
0b4d3452 SM |
536 | else |
537 | sbsec->flags &= ~SBLABEL_MNT; | |
ddd29ec6 | 538 | |
c9180a57 EP |
539 | /* Initialize the root inode. */ |
540 | rc = inode_doinit_with_dentry(root_inode, root); | |
1da177e4 | 541 | |
c9180a57 EP |
542 | /* Initialize any other inodes associated with the superblock, e.g. |
543 | inodes created prior to initial policy load or inodes created | |
544 | during get_sb by a pseudo filesystem that directly | |
545 | populates itself. */ | |
546 | spin_lock(&sbsec->isec_lock); | |
547 | next_inode: | |
548 | if (!list_empty(&sbsec->isec_head)) { | |
549 | struct inode_security_struct *isec = | |
550 | list_entry(sbsec->isec_head.next, | |
551 | struct inode_security_struct, list); | |
552 | struct inode *inode = isec->inode; | |
923190d3 | 553 | list_del_init(&isec->list); |
c9180a57 EP |
554 | spin_unlock(&sbsec->isec_lock); |
555 | inode = igrab(inode); | |
556 | if (inode) { | |
557 | if (!IS_PRIVATE(inode)) | |
558 | inode_doinit(inode); | |
559 | iput(inode); | |
560 | } | |
561 | spin_lock(&sbsec->isec_lock); | |
c9180a57 EP |
562 | goto next_inode; |
563 | } | |
564 | spin_unlock(&sbsec->isec_lock); | |
565 | out: | |
566 | return rc; | |
567 | } | |
1da177e4 | 568 | |
c9180a57 EP |
569 | /* |
570 | * This function should allow an FS to ask what it's mount security | |
571 | * options were so it can use those later for submounts, displaying | |
572 | * mount options, or whatever. | |
573 | */ | |
574 | static int selinux_get_mnt_opts(const struct super_block *sb, | |
e0007529 | 575 | struct security_mnt_opts *opts) |
c9180a57 EP |
576 | { |
577 | int rc = 0, i; | |
578 | struct superblock_security_struct *sbsec = sb->s_security; | |
579 | char *context = NULL; | |
580 | u32 len; | |
581 | char tmp; | |
1da177e4 | 582 | |
e0007529 | 583 | security_init_mnt_opts(opts); |
1da177e4 | 584 | |
0d90a7ec | 585 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
c9180a57 | 586 | return -EINVAL; |
1da177e4 | 587 | |
c9180a57 EP |
588 | if (!ss_initialized) |
589 | return -EINVAL; | |
1da177e4 | 590 | |
af8e50cc EP |
591 | /* make sure we always check enough bits to cover the mask */ |
592 | BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS)); | |
593 | ||
0d90a7ec | 594 | tmp = sbsec->flags & SE_MNTMASK; |
c9180a57 | 595 | /* count the number of mount options for this sb */ |
af8e50cc | 596 | for (i = 0; i < NUM_SEL_MNT_OPTS; i++) { |
c9180a57 | 597 | if (tmp & 0x01) |
e0007529 | 598 | opts->num_mnt_opts++; |
c9180a57 EP |
599 | tmp >>= 1; |
600 | } | |
11689d47 | 601 | /* Check if the Label support flag is set */ |
0b4bdb35 | 602 | if (sbsec->flags & SBLABEL_MNT) |
11689d47 | 603 | opts->num_mnt_opts++; |
1da177e4 | 604 | |
e0007529 EP |
605 | opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); |
606 | if (!opts->mnt_opts) { | |
c9180a57 EP |
607 | rc = -ENOMEM; |
608 | goto out_free; | |
609 | } | |
1da177e4 | 610 | |
e0007529 EP |
611 | opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); |
612 | if (!opts->mnt_opts_flags) { | |
c9180a57 EP |
613 | rc = -ENOMEM; |
614 | goto out_free; | |
615 | } | |
1da177e4 | 616 | |
c9180a57 EP |
617 | i = 0; |
618 | if (sbsec->flags & FSCONTEXT_MNT) { | |
619 | rc = security_sid_to_context(sbsec->sid, &context, &len); | |
620 | if (rc) | |
621 | goto out_free; | |
e0007529 EP |
622 | opts->mnt_opts[i] = context; |
623 | opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; | |
c9180a57 EP |
624 | } |
625 | if (sbsec->flags & CONTEXT_MNT) { | |
626 | rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); | |
627 | if (rc) | |
628 | goto out_free; | |
e0007529 EP |
629 | opts->mnt_opts[i] = context; |
630 | opts->mnt_opts_flags[i++] = CONTEXT_MNT; | |
c9180a57 EP |
631 | } |
632 | if (sbsec->flags & DEFCONTEXT_MNT) { | |
633 | rc = security_sid_to_context(sbsec->def_sid, &context, &len); | |
634 | if (rc) | |
635 | goto out_free; | |
e0007529 EP |
636 | opts->mnt_opts[i] = context; |
637 | opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; | |
c9180a57 EP |
638 | } |
639 | if (sbsec->flags & ROOTCONTEXT_MNT) { | |
83da53c5 AG |
640 | struct dentry *root = sbsec->sb->s_root; |
641 | struct inode_security_struct *isec = backing_inode_security(root); | |
0808925e | 642 | |
c9180a57 EP |
643 | rc = security_sid_to_context(isec->sid, &context, &len); |
644 | if (rc) | |
645 | goto out_free; | |
e0007529 EP |
646 | opts->mnt_opts[i] = context; |
647 | opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; | |
c9180a57 | 648 | } |
12f348b9 | 649 | if (sbsec->flags & SBLABEL_MNT) { |
11689d47 | 650 | opts->mnt_opts[i] = NULL; |
12f348b9 | 651 | opts->mnt_opts_flags[i++] = SBLABEL_MNT; |
11689d47 | 652 | } |
1da177e4 | 653 | |
e0007529 | 654 | BUG_ON(i != opts->num_mnt_opts); |
1da177e4 | 655 | |
c9180a57 EP |
656 | return 0; |
657 | ||
658 | out_free: | |
e0007529 | 659 | security_free_mnt_opts(opts); |
c9180a57 EP |
660 | return rc; |
661 | } | |
1da177e4 | 662 | |
c9180a57 EP |
663 | static int bad_option(struct superblock_security_struct *sbsec, char flag, |
664 | u32 old_sid, u32 new_sid) | |
665 | { | |
0d90a7ec DQ |
666 | char mnt_flags = sbsec->flags & SE_MNTMASK; |
667 | ||
c9180a57 | 668 | /* check if the old mount command had the same options */ |
0d90a7ec | 669 | if (sbsec->flags & SE_SBINITIALIZED) |
c9180a57 EP |
670 | if (!(sbsec->flags & flag) || |
671 | (old_sid != new_sid)) | |
672 | return 1; | |
673 | ||
674 | /* check if we were passed the same options twice, | |
675 | * aka someone passed context=a,context=b | |
676 | */ | |
0d90a7ec DQ |
677 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
678 | if (mnt_flags & flag) | |
c9180a57 EP |
679 | return 1; |
680 | return 0; | |
681 | } | |
e0007529 | 682 | |
c9180a57 EP |
683 | /* |
684 | * Allow filesystems with binary mount data to explicitly set mount point | |
685 | * labeling information. | |
686 | */ | |
e0007529 | 687 | static int selinux_set_mnt_opts(struct super_block *sb, |
649f6e77 DQ |
688 | struct security_mnt_opts *opts, |
689 | unsigned long kern_flags, | |
690 | unsigned long *set_kern_flags) | |
c9180a57 | 691 | { |
275bb41e | 692 | const struct cred *cred = current_cred(); |
c9180a57 | 693 | int rc = 0, i; |
c9180a57 | 694 | struct superblock_security_struct *sbsec = sb->s_security; |
29b1deb2 | 695 | const char *name = sb->s_type->name; |
83da53c5 | 696 | struct dentry *root = sbsec->sb->s_root; |
2c97165b | 697 | struct inode_security_struct *root_isec; |
c9180a57 EP |
698 | u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; |
699 | u32 defcontext_sid = 0; | |
e0007529 EP |
700 | char **mount_options = opts->mnt_opts; |
701 | int *flags = opts->mnt_opts_flags; | |
702 | int num_opts = opts->num_mnt_opts; | |
c9180a57 EP |
703 | |
704 | mutex_lock(&sbsec->lock); | |
705 | ||
706 | if (!ss_initialized) { | |
707 | if (!num_opts) { | |
708 | /* Defer initialization until selinux_complete_init, | |
709 | after the initial policy is loaded and the security | |
710 | server is ready to handle calls. */ | |
c9180a57 EP |
711 | goto out; |
712 | } | |
713 | rc = -EINVAL; | |
744ba35e EP |
714 | printk(KERN_WARNING "SELinux: Unable to set superblock options " |
715 | "before the security server is initialized\n"); | |
1da177e4 | 716 | goto out; |
c9180a57 | 717 | } |
649f6e77 DQ |
718 | if (kern_flags && !set_kern_flags) { |
719 | /* Specifying internal flags without providing a place to | |
720 | * place the results is not allowed */ | |
721 | rc = -EINVAL; | |
722 | goto out; | |
723 | } | |
1da177e4 | 724 | |
e0007529 EP |
725 | /* |
726 | * Binary mount data FS will come through this function twice. Once | |
727 | * from an explicit call and once from the generic calls from the vfs. | |
728 | * Since the generic VFS calls will not contain any security mount data | |
729 | * we need to skip the double mount verification. | |
730 | * | |
731 | * This does open a hole in which we will not notice if the first | |
732 | * mount using this sb set explict options and a second mount using | |
733 | * this sb does not set any security options. (The first options | |
734 | * will be used for both mounts) | |
735 | */ | |
0d90a7ec | 736 | if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) |
e0007529 | 737 | && (num_opts == 0)) |
f5269710 | 738 | goto out; |
e0007529 | 739 | |
2c97165b PM |
740 | root_isec = backing_inode_security_novalidate(root); |
741 | ||
c9180a57 EP |
742 | /* |
743 | * parse the mount options, check if they are valid sids. | |
744 | * also check if someone is trying to mount the same sb more | |
745 | * than once with different security options. | |
746 | */ | |
747 | for (i = 0; i < num_opts; i++) { | |
748 | u32 sid; | |
11689d47 | 749 | |
12f348b9 | 750 | if (flags[i] == SBLABEL_MNT) |
11689d47 | 751 | continue; |
44be2f65 | 752 | rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL); |
1da177e4 | 753 | if (rc) { |
44be2f65 | 754 | printk(KERN_WARNING "SELinux: security_context_str_to_sid" |
29b1deb2 LT |
755 | "(%s) failed for (dev %s, type %s) errno=%d\n", |
756 | mount_options[i], sb->s_id, name, rc); | |
c9180a57 EP |
757 | goto out; |
758 | } | |
759 | switch (flags[i]) { | |
760 | case FSCONTEXT_MNT: | |
761 | fscontext_sid = sid; | |
762 | ||
763 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, | |
764 | fscontext_sid)) | |
765 | goto out_double_mount; | |
766 | ||
767 | sbsec->flags |= FSCONTEXT_MNT; | |
768 | break; | |
769 | case CONTEXT_MNT: | |
770 | context_sid = sid; | |
771 | ||
772 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, | |
773 | context_sid)) | |
774 | goto out_double_mount; | |
775 | ||
776 | sbsec->flags |= CONTEXT_MNT; | |
777 | break; | |
778 | case ROOTCONTEXT_MNT: | |
779 | rootcontext_sid = sid; | |
780 | ||
781 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, | |
782 | rootcontext_sid)) | |
783 | goto out_double_mount; | |
784 | ||
785 | sbsec->flags |= ROOTCONTEXT_MNT; | |
786 | ||
787 | break; | |
788 | case DEFCONTEXT_MNT: | |
789 | defcontext_sid = sid; | |
790 | ||
791 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, | |
792 | defcontext_sid)) | |
793 | goto out_double_mount; | |
794 | ||
795 | sbsec->flags |= DEFCONTEXT_MNT; | |
796 | ||
797 | break; | |
798 | default: | |
799 | rc = -EINVAL; | |
800 | goto out; | |
1da177e4 | 801 | } |
c9180a57 EP |
802 | } |
803 | ||
0d90a7ec | 804 | if (sbsec->flags & SE_SBINITIALIZED) { |
c9180a57 | 805 | /* previously mounted with options, but not on this attempt? */ |
0d90a7ec | 806 | if ((sbsec->flags & SE_MNTMASK) && !num_opts) |
c9180a57 EP |
807 | goto out_double_mount; |
808 | rc = 0; | |
809 | goto out; | |
810 | } | |
811 | ||
089be43e | 812 | if (strcmp(sb->s_type->name, "proc") == 0) |
134509d5 SS |
813 | sbsec->flags |= SE_SBPROC | SE_SBGENFS; |
814 | ||
8e014720 | 815 | if (!strcmp(sb->s_type->name, "debugfs") || |
6a391183 | 816 | !strcmp(sb->s_type->name, "tracefs") || |
8e014720 | 817 | !strcmp(sb->s_type->name, "sysfs") || |
901ef845 AM |
818 | !strcmp(sb->s_type->name, "pstore") || |
819 | !strcmp(sb->s_type->name, "cgroup") || | |
820 | !strcmp(sb->s_type->name, "cgroup2")) | |
134509d5 | 821 | sbsec->flags |= SE_SBGENFS; |
c9180a57 | 822 | |
eb9ae686 DQ |
823 | if (!sbsec->behavior) { |
824 | /* | |
825 | * Determine the labeling behavior to use for this | |
826 | * filesystem type. | |
827 | */ | |
98f700f3 | 828 | rc = security_fs_use(sb); |
eb9ae686 DQ |
829 | if (rc) { |
830 | printk(KERN_WARNING | |
831 | "%s: security_fs_use(%s) returned %d\n", | |
832 | __func__, sb->s_type->name, rc); | |
833 | goto out; | |
834 | } | |
c9180a57 | 835 | } |
aad82892 SF |
836 | |
837 | /* | |
01593d32 SS |
838 | * If this is a user namespace mount and the filesystem type is not |
839 | * explicitly whitelisted, then no contexts are allowed on the command | |
840 | * line and security labels must be ignored. | |
aad82892 | 841 | */ |
01593d32 SS |
842 | if (sb->s_user_ns != &init_user_ns && |
843 | strcmp(sb->s_type->name, "tmpfs") && | |
844 | strcmp(sb->s_type->name, "ramfs") && | |
845 | strcmp(sb->s_type->name, "devpts")) { | |
aad82892 SF |
846 | if (context_sid || fscontext_sid || rootcontext_sid || |
847 | defcontext_sid) { | |
848 | rc = -EACCES; | |
849 | goto out; | |
850 | } | |
851 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { | |
852 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; | |
853 | rc = security_transition_sid(current_sid(), current_sid(), | |
854 | SECCLASS_FILE, NULL, | |
855 | &sbsec->mntpoint_sid); | |
856 | if (rc) | |
857 | goto out; | |
858 | } | |
859 | goto out_set_opts; | |
860 | } | |
861 | ||
c9180a57 EP |
862 | /* sets the context of the superblock for the fs being mounted. */ |
863 | if (fscontext_sid) { | |
275bb41e | 864 | rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); |
1da177e4 | 865 | if (rc) |
c9180a57 | 866 | goto out; |
1da177e4 | 867 | |
c9180a57 | 868 | sbsec->sid = fscontext_sid; |
c312feb2 EP |
869 | } |
870 | ||
871 | /* | |
872 | * Switch to using mount point labeling behavior. | |
873 | * sets the label used on all file below the mountpoint, and will set | |
874 | * the superblock context if not already set. | |
875 | */ | |
eb9ae686 DQ |
876 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) { |
877 | sbsec->behavior = SECURITY_FS_USE_NATIVE; | |
878 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
879 | } | |
880 | ||
c9180a57 EP |
881 | if (context_sid) { |
882 | if (!fscontext_sid) { | |
275bb41e DH |
883 | rc = may_context_mount_sb_relabel(context_sid, sbsec, |
884 | cred); | |
b04ea3ce | 885 | if (rc) |
c9180a57 EP |
886 | goto out; |
887 | sbsec->sid = context_sid; | |
b04ea3ce | 888 | } else { |
275bb41e DH |
889 | rc = may_context_mount_inode_relabel(context_sid, sbsec, |
890 | cred); | |
b04ea3ce | 891 | if (rc) |
c9180a57 | 892 | goto out; |
b04ea3ce | 893 | } |
c9180a57 EP |
894 | if (!rootcontext_sid) |
895 | rootcontext_sid = context_sid; | |
1da177e4 | 896 | |
c9180a57 | 897 | sbsec->mntpoint_sid = context_sid; |
c312feb2 | 898 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; |
1da177e4 LT |
899 | } |
900 | ||
c9180a57 | 901 | if (rootcontext_sid) { |
275bb41e DH |
902 | rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, |
903 | cred); | |
0808925e | 904 | if (rc) |
c9180a57 | 905 | goto out; |
0808925e | 906 | |
c9180a57 | 907 | root_isec->sid = rootcontext_sid; |
6f3be9f5 | 908 | root_isec->initialized = LABEL_INITIALIZED; |
0808925e EP |
909 | } |
910 | ||
c9180a57 | 911 | if (defcontext_sid) { |
eb9ae686 DQ |
912 | if (sbsec->behavior != SECURITY_FS_USE_XATTR && |
913 | sbsec->behavior != SECURITY_FS_USE_NATIVE) { | |
c9180a57 EP |
914 | rc = -EINVAL; |
915 | printk(KERN_WARNING "SELinux: defcontext option is " | |
916 | "invalid for this filesystem type\n"); | |
917 | goto out; | |
1da177e4 LT |
918 | } |
919 | ||
c9180a57 EP |
920 | if (defcontext_sid != sbsec->def_sid) { |
921 | rc = may_context_mount_inode_relabel(defcontext_sid, | |
275bb41e | 922 | sbsec, cred); |
c9180a57 EP |
923 | if (rc) |
924 | goto out; | |
925 | } | |
1da177e4 | 926 | |
c9180a57 | 927 | sbsec->def_sid = defcontext_sid; |
1da177e4 LT |
928 | } |
929 | ||
aad82892 | 930 | out_set_opts: |
c9180a57 | 931 | rc = sb_finish_set_opts(sb); |
1da177e4 | 932 | out: |
c9180a57 | 933 | mutex_unlock(&sbsec->lock); |
1da177e4 | 934 | return rc; |
c9180a57 EP |
935 | out_double_mount: |
936 | rc = -EINVAL; | |
937 | printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " | |
29b1deb2 | 938 | "security settings for (dev %s, type %s)\n", sb->s_id, name); |
c9180a57 | 939 | goto out; |
1da177e4 LT |
940 | } |
941 | ||
094f7b69 JL |
942 | static int selinux_cmp_sb_context(const struct super_block *oldsb, |
943 | const struct super_block *newsb) | |
944 | { | |
945 | struct superblock_security_struct *old = oldsb->s_security; | |
946 | struct superblock_security_struct *new = newsb->s_security; | |
947 | char oldflags = old->flags & SE_MNTMASK; | |
948 | char newflags = new->flags & SE_MNTMASK; | |
949 | ||
950 | if (oldflags != newflags) | |
951 | goto mismatch; | |
952 | if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid) | |
953 | goto mismatch; | |
954 | if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid) | |
955 | goto mismatch; | |
956 | if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid) | |
957 | goto mismatch; | |
958 | if (oldflags & ROOTCONTEXT_MNT) { | |
83da53c5 AG |
959 | struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root); |
960 | struct inode_security_struct *newroot = backing_inode_security(newsb->s_root); | |
094f7b69 JL |
961 | if (oldroot->sid != newroot->sid) |
962 | goto mismatch; | |
963 | } | |
964 | return 0; | |
965 | mismatch: | |
966 | printk(KERN_WARNING "SELinux: mount invalid. Same superblock, " | |
967 | "different security settings for (dev %s, " | |
968 | "type %s)\n", newsb->s_id, newsb->s_type->name); | |
969 | return -EBUSY; | |
970 | } | |
971 | ||
972 | static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, | |
0b4d3452 SM |
973 | struct super_block *newsb, |
974 | unsigned long kern_flags, | |
975 | unsigned long *set_kern_flags) | |
1da177e4 | 976 | { |
0b4d3452 | 977 | int rc = 0; |
c9180a57 EP |
978 | const struct superblock_security_struct *oldsbsec = oldsb->s_security; |
979 | struct superblock_security_struct *newsbsec = newsb->s_security; | |
1da177e4 | 980 | |
c9180a57 EP |
981 | int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); |
982 | int set_context = (oldsbsec->flags & CONTEXT_MNT); | |
983 | int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); | |
1da177e4 | 984 | |
0f5e6420 EP |
985 | /* |
986 | * if the parent was able to be mounted it clearly had no special lsm | |
e8c26255 | 987 | * mount options. thus we can safely deal with this superblock later |
0f5e6420 | 988 | */ |
e8c26255 | 989 | if (!ss_initialized) |
094f7b69 | 990 | return 0; |
c9180a57 | 991 | |
0b4d3452 SM |
992 | /* |
993 | * Specifying internal flags without providing a place to | |
994 | * place the results is not allowed. | |
995 | */ | |
996 | if (kern_flags && !set_kern_flags) | |
997 | return -EINVAL; | |
998 | ||
c9180a57 | 999 | /* how can we clone if the old one wasn't set up?? */ |
0d90a7ec | 1000 | BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); |
c9180a57 | 1001 | |
094f7b69 | 1002 | /* if fs is reusing a sb, make sure that the contexts match */ |
0d90a7ec | 1003 | if (newsbsec->flags & SE_SBINITIALIZED) |
094f7b69 | 1004 | return selinux_cmp_sb_context(oldsb, newsb); |
5a552617 | 1005 | |
c9180a57 EP |
1006 | mutex_lock(&newsbsec->lock); |
1007 | ||
1008 | newsbsec->flags = oldsbsec->flags; | |
1009 | ||
1010 | newsbsec->sid = oldsbsec->sid; | |
1011 | newsbsec->def_sid = oldsbsec->def_sid; | |
1012 | newsbsec->behavior = oldsbsec->behavior; | |
1013 | ||
0b4d3452 SM |
1014 | if (newsbsec->behavior == SECURITY_FS_USE_NATIVE && |
1015 | !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) { | |
1016 | rc = security_fs_use(newsb); | |
1017 | if (rc) | |
1018 | goto out; | |
1019 | } | |
1020 | ||
1021 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) { | |
1022 | newsbsec->behavior = SECURITY_FS_USE_NATIVE; | |
1023 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
1024 | } | |
1025 | ||
c9180a57 EP |
1026 | if (set_context) { |
1027 | u32 sid = oldsbsec->mntpoint_sid; | |
1028 | ||
1029 | if (!set_fscontext) | |
1030 | newsbsec->sid = sid; | |
1031 | if (!set_rootcontext) { | |
83da53c5 | 1032 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); |
c9180a57 EP |
1033 | newisec->sid = sid; |
1034 | } | |
1035 | newsbsec->mntpoint_sid = sid; | |
1da177e4 | 1036 | } |
c9180a57 | 1037 | if (set_rootcontext) { |
83da53c5 AG |
1038 | const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root); |
1039 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); | |
1da177e4 | 1040 | |
c9180a57 | 1041 | newisec->sid = oldisec->sid; |
1da177e4 LT |
1042 | } |
1043 | ||
c9180a57 | 1044 | sb_finish_set_opts(newsb); |
0b4d3452 | 1045 | out: |
c9180a57 | 1046 | mutex_unlock(&newsbsec->lock); |
0b4d3452 | 1047 | return rc; |
c9180a57 EP |
1048 | } |
1049 | ||
2e1479d9 AB |
1050 | static int selinux_parse_opts_str(char *options, |
1051 | struct security_mnt_opts *opts) | |
c9180a57 | 1052 | { |
e0007529 | 1053 | char *p; |
c9180a57 EP |
1054 | char *context = NULL, *defcontext = NULL; |
1055 | char *fscontext = NULL, *rootcontext = NULL; | |
e0007529 | 1056 | int rc, num_mnt_opts = 0; |
1da177e4 | 1057 | |
e0007529 | 1058 | opts->num_mnt_opts = 0; |
1da177e4 | 1059 | |
c9180a57 EP |
1060 | /* Standard string-based options. */ |
1061 | while ((p = strsep(&options, "|")) != NULL) { | |
1062 | int token; | |
1063 | substring_t args[MAX_OPT_ARGS]; | |
1da177e4 | 1064 | |
c9180a57 EP |
1065 | if (!*p) |
1066 | continue; | |
1da177e4 | 1067 | |
c9180a57 | 1068 | token = match_token(p, tokens, args); |
1da177e4 | 1069 | |
c9180a57 EP |
1070 | switch (token) { |
1071 | case Opt_context: | |
1072 | if (context || defcontext) { | |
1073 | rc = -EINVAL; | |
1074 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1075 | goto out_err; | |
1076 | } | |
1077 | context = match_strdup(&args[0]); | |
1078 | if (!context) { | |
1079 | rc = -ENOMEM; | |
1080 | goto out_err; | |
1081 | } | |
1082 | break; | |
1083 | ||
1084 | case Opt_fscontext: | |
1085 | if (fscontext) { | |
1086 | rc = -EINVAL; | |
1087 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1088 | goto out_err; | |
1089 | } | |
1090 | fscontext = match_strdup(&args[0]); | |
1091 | if (!fscontext) { | |
1092 | rc = -ENOMEM; | |
1093 | goto out_err; | |
1094 | } | |
1095 | break; | |
1096 | ||
1097 | case Opt_rootcontext: | |
1098 | if (rootcontext) { | |
1099 | rc = -EINVAL; | |
1100 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1101 | goto out_err; | |
1102 | } | |
1103 | rootcontext = match_strdup(&args[0]); | |
1104 | if (!rootcontext) { | |
1105 | rc = -ENOMEM; | |
1106 | goto out_err; | |
1107 | } | |
1108 | break; | |
1109 | ||
1110 | case Opt_defcontext: | |
1111 | if (context || defcontext) { | |
1112 | rc = -EINVAL; | |
1113 | printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); | |
1114 | goto out_err; | |
1115 | } | |
1116 | defcontext = match_strdup(&args[0]); | |
1117 | if (!defcontext) { | |
1118 | rc = -ENOMEM; | |
1119 | goto out_err; | |
1120 | } | |
1121 | break; | |
11689d47 DQ |
1122 | case Opt_labelsupport: |
1123 | break; | |
c9180a57 EP |
1124 | default: |
1125 | rc = -EINVAL; | |
1126 | printk(KERN_WARNING "SELinux: unknown mount option\n"); | |
1127 | goto out_err; | |
1da177e4 | 1128 | |
1da177e4 | 1129 | } |
1da177e4 | 1130 | } |
c9180a57 | 1131 | |
e0007529 | 1132 | rc = -ENOMEM; |
8931c3bd | 1133 | opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_KERNEL); |
e0007529 EP |
1134 | if (!opts->mnt_opts) |
1135 | goto out_err; | |
1136 | ||
8931c3bd TH |
1137 | opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), |
1138 | GFP_KERNEL); | |
023f108d | 1139 | if (!opts->mnt_opts_flags) |
e0007529 | 1140 | goto out_err; |
e0007529 | 1141 | |
c9180a57 | 1142 | if (fscontext) { |
e0007529 EP |
1143 | opts->mnt_opts[num_mnt_opts] = fscontext; |
1144 | opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; | |
c9180a57 EP |
1145 | } |
1146 | if (context) { | |
e0007529 EP |
1147 | opts->mnt_opts[num_mnt_opts] = context; |
1148 | opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; | |
c9180a57 EP |
1149 | } |
1150 | if (rootcontext) { | |
e0007529 EP |
1151 | opts->mnt_opts[num_mnt_opts] = rootcontext; |
1152 | opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; | |
c9180a57 EP |
1153 | } |
1154 | if (defcontext) { | |
e0007529 EP |
1155 | opts->mnt_opts[num_mnt_opts] = defcontext; |
1156 | opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; | |
c9180a57 EP |
1157 | } |
1158 | ||
e0007529 EP |
1159 | opts->num_mnt_opts = num_mnt_opts; |
1160 | return 0; | |
1161 | ||
c9180a57 | 1162 | out_err: |
023f108d | 1163 | security_free_mnt_opts(opts); |
c9180a57 EP |
1164 | kfree(context); |
1165 | kfree(defcontext); | |
1166 | kfree(fscontext); | |
1167 | kfree(rootcontext); | |
1da177e4 LT |
1168 | return rc; |
1169 | } | |
e0007529 EP |
1170 | /* |
1171 | * string mount options parsing and call set the sbsec | |
1172 | */ | |
1173 | static int superblock_doinit(struct super_block *sb, void *data) | |
1174 | { | |
1175 | int rc = 0; | |
1176 | char *options = data; | |
1177 | struct security_mnt_opts opts; | |
1178 | ||
1179 | security_init_mnt_opts(&opts); | |
1180 | ||
1181 | if (!data) | |
1182 | goto out; | |
1183 | ||
1184 | BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); | |
1185 | ||
1186 | rc = selinux_parse_opts_str(options, &opts); | |
1187 | if (rc) | |
1188 | goto out_err; | |
1189 | ||
1190 | out: | |
649f6e77 | 1191 | rc = selinux_set_mnt_opts(sb, &opts, 0, NULL); |
e0007529 EP |
1192 | |
1193 | out_err: | |
1194 | security_free_mnt_opts(&opts); | |
1195 | return rc; | |
1196 | } | |
1da177e4 | 1197 | |
3583a711 AB |
1198 | static void selinux_write_opts(struct seq_file *m, |
1199 | struct security_mnt_opts *opts) | |
2069f457 EP |
1200 | { |
1201 | int i; | |
1202 | char *prefix; | |
1203 | ||
1204 | for (i = 0; i < opts->num_mnt_opts; i++) { | |
11689d47 DQ |
1205 | char *has_comma; |
1206 | ||
1207 | if (opts->mnt_opts[i]) | |
1208 | has_comma = strchr(opts->mnt_opts[i], ','); | |
1209 | else | |
1210 | has_comma = NULL; | |
2069f457 EP |
1211 | |
1212 | switch (opts->mnt_opts_flags[i]) { | |
1213 | case CONTEXT_MNT: | |
1214 | prefix = CONTEXT_STR; | |
1215 | break; | |
1216 | case FSCONTEXT_MNT: | |
1217 | prefix = FSCONTEXT_STR; | |
1218 | break; | |
1219 | case ROOTCONTEXT_MNT: | |
1220 | prefix = ROOTCONTEXT_STR; | |
1221 | break; | |
1222 | case DEFCONTEXT_MNT: | |
1223 | prefix = DEFCONTEXT_STR; | |
1224 | break; | |
12f348b9 | 1225 | case SBLABEL_MNT: |
11689d47 DQ |
1226 | seq_putc(m, ','); |
1227 | seq_puts(m, LABELSUPP_STR); | |
1228 | continue; | |
2069f457 EP |
1229 | default: |
1230 | BUG(); | |
a35c6c83 | 1231 | return; |
2069f457 EP |
1232 | }; |
1233 | /* we need a comma before each option */ | |
1234 | seq_putc(m, ','); | |
1235 | seq_puts(m, prefix); | |
1236 | if (has_comma) | |
1237 | seq_putc(m, '\"'); | |
a068acf2 | 1238 | seq_escape(m, opts->mnt_opts[i], "\"\n\\"); |
2069f457 EP |
1239 | if (has_comma) |
1240 | seq_putc(m, '\"'); | |
1241 | } | |
1242 | } | |
1243 | ||
1244 | static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) | |
1245 | { | |
1246 | struct security_mnt_opts opts; | |
1247 | int rc; | |
1248 | ||
1249 | rc = selinux_get_mnt_opts(sb, &opts); | |
383795c2 EP |
1250 | if (rc) { |
1251 | /* before policy load we may get EINVAL, don't show anything */ | |
1252 | if (rc == -EINVAL) | |
1253 | rc = 0; | |
2069f457 | 1254 | return rc; |
383795c2 | 1255 | } |
2069f457 EP |
1256 | |
1257 | selinux_write_opts(m, &opts); | |
1258 | ||
1259 | security_free_mnt_opts(&opts); | |
1260 | ||
1261 | return rc; | |
1262 | } | |
1263 | ||
1da177e4 LT |
1264 | static inline u16 inode_mode_to_security_class(umode_t mode) |
1265 | { | |
1266 | switch (mode & S_IFMT) { | |
1267 | case S_IFSOCK: | |
1268 | return SECCLASS_SOCK_FILE; | |
1269 | case S_IFLNK: | |
1270 | return SECCLASS_LNK_FILE; | |
1271 | case S_IFREG: | |
1272 | return SECCLASS_FILE; | |
1273 | case S_IFBLK: | |
1274 | return SECCLASS_BLK_FILE; | |
1275 | case S_IFDIR: | |
1276 | return SECCLASS_DIR; | |
1277 | case S_IFCHR: | |
1278 | return SECCLASS_CHR_FILE; | |
1279 | case S_IFIFO: | |
1280 | return SECCLASS_FIFO_FILE; | |
1281 | ||
1282 | } | |
1283 | ||
1284 | return SECCLASS_FILE; | |
1285 | } | |
1286 | ||
13402580 JM |
1287 | static inline int default_protocol_stream(int protocol) |
1288 | { | |
1289 | return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); | |
1290 | } | |
1291 | ||
1292 | static inline int default_protocol_dgram(int protocol) | |
1293 | { | |
1294 | return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); | |
1295 | } | |
1296 | ||
1da177e4 LT |
1297 | static inline u16 socket_type_to_security_class(int family, int type, int protocol) |
1298 | { | |
da69a530 SS |
1299 | int extsockclass = selinux_policycap_extsockclass; |
1300 | ||
1da177e4 LT |
1301 | switch (family) { |
1302 | case PF_UNIX: | |
1303 | switch (type) { | |
1304 | case SOCK_STREAM: | |
1305 | case SOCK_SEQPACKET: | |
1306 | return SECCLASS_UNIX_STREAM_SOCKET; | |
1307 | case SOCK_DGRAM: | |
2a764b52 | 1308 | case SOCK_RAW: |
1da177e4 LT |
1309 | return SECCLASS_UNIX_DGRAM_SOCKET; |
1310 | } | |
1311 | break; | |
1312 | case PF_INET: | |
1313 | case PF_INET6: | |
1314 | switch (type) { | |
1315 | case SOCK_STREAM: | |
da69a530 | 1316 | case SOCK_SEQPACKET: |
13402580 JM |
1317 | if (default_protocol_stream(protocol)) |
1318 | return SECCLASS_TCP_SOCKET; | |
da69a530 SS |
1319 | else if (extsockclass && protocol == IPPROTO_SCTP) |
1320 | return SECCLASS_SCTP_SOCKET; | |
13402580 JM |
1321 | else |
1322 | return SECCLASS_RAWIP_SOCKET; | |
1da177e4 | 1323 | case SOCK_DGRAM: |
13402580 JM |
1324 | if (default_protocol_dgram(protocol)) |
1325 | return SECCLASS_UDP_SOCKET; | |
ef37979a SS |
1326 | else if (extsockclass && (protocol == IPPROTO_ICMP || |
1327 | protocol == IPPROTO_ICMPV6)) | |
da69a530 | 1328 | return SECCLASS_ICMP_SOCKET; |
13402580 JM |
1329 | else |
1330 | return SECCLASS_RAWIP_SOCKET; | |
2ee92d46 JM |
1331 | case SOCK_DCCP: |
1332 | return SECCLASS_DCCP_SOCKET; | |
13402580 | 1333 | default: |
1da177e4 LT |
1334 | return SECCLASS_RAWIP_SOCKET; |
1335 | } | |
1336 | break; | |
1337 | case PF_NETLINK: | |
1338 | switch (protocol) { | |
1339 | case NETLINK_ROUTE: | |
1340 | return SECCLASS_NETLINK_ROUTE_SOCKET; | |
7f1fb60c | 1341 | case NETLINK_SOCK_DIAG: |
1da177e4 LT |
1342 | return SECCLASS_NETLINK_TCPDIAG_SOCKET; |
1343 | case NETLINK_NFLOG: | |
1344 | return SECCLASS_NETLINK_NFLOG_SOCKET; | |
1345 | case NETLINK_XFRM: | |
1346 | return SECCLASS_NETLINK_XFRM_SOCKET; | |
1347 | case NETLINK_SELINUX: | |
1348 | return SECCLASS_NETLINK_SELINUX_SOCKET; | |
6c6d2e9b SS |
1349 | case NETLINK_ISCSI: |
1350 | return SECCLASS_NETLINK_ISCSI_SOCKET; | |
1da177e4 LT |
1351 | case NETLINK_AUDIT: |
1352 | return SECCLASS_NETLINK_AUDIT_SOCKET; | |
6c6d2e9b SS |
1353 | case NETLINK_FIB_LOOKUP: |
1354 | return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET; | |
1355 | case NETLINK_CONNECTOR: | |
1356 | return SECCLASS_NETLINK_CONNECTOR_SOCKET; | |
1357 | case NETLINK_NETFILTER: | |
1358 | return SECCLASS_NETLINK_NETFILTER_SOCKET; | |
1da177e4 LT |
1359 | case NETLINK_DNRTMSG: |
1360 | return SECCLASS_NETLINK_DNRT_SOCKET; | |
0c9b7942 JM |
1361 | case NETLINK_KOBJECT_UEVENT: |
1362 | return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; | |
6c6d2e9b SS |
1363 | case NETLINK_GENERIC: |
1364 | return SECCLASS_NETLINK_GENERIC_SOCKET; | |
1365 | case NETLINK_SCSITRANSPORT: | |
1366 | return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET; | |
1367 | case NETLINK_RDMA: | |
1368 | return SECCLASS_NETLINK_RDMA_SOCKET; | |
1369 | case NETLINK_CRYPTO: | |
1370 | return SECCLASS_NETLINK_CRYPTO_SOCKET; | |
1da177e4 LT |
1371 | default: |
1372 | return SECCLASS_NETLINK_SOCKET; | |
1373 | } | |
1374 | case PF_PACKET: | |
1375 | return SECCLASS_PACKET_SOCKET; | |
1376 | case PF_KEY: | |
1377 | return SECCLASS_KEY_SOCKET; | |
3e3ff15e CP |
1378 | case PF_APPLETALK: |
1379 | return SECCLASS_APPLETALK_SOCKET; | |
1da177e4 LT |
1380 | } |
1381 | ||
da69a530 SS |
1382 | if (extsockclass) { |
1383 | switch (family) { | |
1384 | case PF_AX25: | |
1385 | return SECCLASS_AX25_SOCKET; | |
1386 | case PF_IPX: | |
1387 | return SECCLASS_IPX_SOCKET; | |
1388 | case PF_NETROM: | |
1389 | return SECCLASS_NETROM_SOCKET; | |
da69a530 SS |
1390 | case PF_ATMPVC: |
1391 | return SECCLASS_ATMPVC_SOCKET; | |
1392 | case PF_X25: | |
1393 | return SECCLASS_X25_SOCKET; | |
1394 | case PF_ROSE: | |
1395 | return SECCLASS_ROSE_SOCKET; | |
1396 | case PF_DECnet: | |
1397 | return SECCLASS_DECNET_SOCKET; | |
1398 | case PF_ATMSVC: | |
1399 | return SECCLASS_ATMSVC_SOCKET; | |
1400 | case PF_RDS: | |
1401 | return SECCLASS_RDS_SOCKET; | |
1402 | case PF_IRDA: | |
1403 | return SECCLASS_IRDA_SOCKET; | |
1404 | case PF_PPPOX: | |
1405 | return SECCLASS_PPPOX_SOCKET; | |
1406 | case PF_LLC: | |
1407 | return SECCLASS_LLC_SOCKET; | |
da69a530 SS |
1408 | case PF_CAN: |
1409 | return SECCLASS_CAN_SOCKET; | |
1410 | case PF_TIPC: | |
1411 | return SECCLASS_TIPC_SOCKET; | |
1412 | case PF_BLUETOOTH: | |
1413 | return SECCLASS_BLUETOOTH_SOCKET; | |
1414 | case PF_IUCV: | |
1415 | return SECCLASS_IUCV_SOCKET; | |
1416 | case PF_RXRPC: | |
1417 | return SECCLASS_RXRPC_SOCKET; | |
1418 | case PF_ISDN: | |
1419 | return SECCLASS_ISDN_SOCKET; | |
1420 | case PF_PHONET: | |
1421 | return SECCLASS_PHONET_SOCKET; | |
1422 | case PF_IEEE802154: | |
1423 | return SECCLASS_IEEE802154_SOCKET; | |
1424 | case PF_CAIF: | |
1425 | return SECCLASS_CAIF_SOCKET; | |
1426 | case PF_ALG: | |
1427 | return SECCLASS_ALG_SOCKET; | |
1428 | case PF_NFC: | |
1429 | return SECCLASS_NFC_SOCKET; | |
1430 | case PF_VSOCK: | |
1431 | return SECCLASS_VSOCK_SOCKET; | |
1432 | case PF_KCM: | |
1433 | return SECCLASS_KCM_SOCKET; | |
1434 | case PF_QIPCRTR: | |
1435 | return SECCLASS_QIPCRTR_SOCKET; | |
3051bf36 LT |
1436 | case PF_SMC: |
1437 | return SECCLASS_SMC_SOCKET; | |
1438 | #if PF_MAX > 44 | |
da69a530 SS |
1439 | #error New address family defined, please update this function. |
1440 | #endif | |
1441 | } | |
1442 | } | |
1443 | ||
1da177e4 LT |
1444 | return SECCLASS_SOCKET; |
1445 | } | |
1446 | ||
134509d5 SS |
1447 | static int selinux_genfs_get_sid(struct dentry *dentry, |
1448 | u16 tclass, | |
1449 | u16 flags, | |
1450 | u32 *sid) | |
1da177e4 | 1451 | { |
8e6c9693 | 1452 | int rc; |
fc64005c | 1453 | struct super_block *sb = dentry->d_sb; |
8e6c9693 | 1454 | char *buffer, *path; |
1da177e4 | 1455 | |
828dfe1d | 1456 | buffer = (char *)__get_free_page(GFP_KERNEL); |
1da177e4 LT |
1457 | if (!buffer) |
1458 | return -ENOMEM; | |
1459 | ||
8e6c9693 LAG |
1460 | path = dentry_path_raw(dentry, buffer, PAGE_SIZE); |
1461 | if (IS_ERR(path)) | |
1462 | rc = PTR_ERR(path); | |
1463 | else { | |
134509d5 SS |
1464 | if (flags & SE_SBPROC) { |
1465 | /* each process gets a /proc/PID/ entry. Strip off the | |
1466 | * PID part to get a valid selinux labeling. | |
1467 | * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ | |
1468 | while (path[1] >= '0' && path[1] <= '9') { | |
1469 | path[1] = '/'; | |
1470 | path++; | |
1471 | } | |
8e6c9693 | 1472 | } |
134509d5 | 1473 | rc = security_genfs_sid(sb->s_type->name, path, tclass, sid); |
1da177e4 | 1474 | } |
1da177e4 LT |
1475 | free_page((unsigned long)buffer); |
1476 | return rc; | |
1477 | } | |
1da177e4 LT |
1478 | |
1479 | /* The inode's security attributes must be initialized before first use. */ | |
1480 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) | |
1481 | { | |
1482 | struct superblock_security_struct *sbsec = NULL; | |
1483 | struct inode_security_struct *isec = inode->i_security; | |
9287aed2 AG |
1484 | u32 task_sid, sid = 0; |
1485 | u16 sclass; | |
1da177e4 LT |
1486 | struct dentry *dentry; |
1487 | #define INITCONTEXTLEN 255 | |
1488 | char *context = NULL; | |
1489 | unsigned len = 0; | |
1490 | int rc = 0; | |
1da177e4 | 1491 | |
6f3be9f5 | 1492 | if (isec->initialized == LABEL_INITIALIZED) |
13457d07 | 1493 | return 0; |
1da177e4 | 1494 | |
9287aed2 | 1495 | spin_lock(&isec->lock); |
6f3be9f5 | 1496 | if (isec->initialized == LABEL_INITIALIZED) |
23970741 | 1497 | goto out_unlock; |
1da177e4 | 1498 | |
13457d07 AG |
1499 | if (isec->sclass == SECCLASS_FILE) |
1500 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
1501 | ||
1da177e4 | 1502 | sbsec = inode->i_sb->s_security; |
0d90a7ec | 1503 | if (!(sbsec->flags & SE_SBINITIALIZED)) { |
1da177e4 LT |
1504 | /* Defer initialization until selinux_complete_init, |
1505 | after the initial policy is loaded and the security | |
1506 | server is ready to handle calls. */ | |
1507 | spin_lock(&sbsec->isec_lock); | |
1508 | if (list_empty(&isec->list)) | |
1509 | list_add(&isec->list, &sbsec->isec_head); | |
1510 | spin_unlock(&sbsec->isec_lock); | |
23970741 | 1511 | goto out_unlock; |
1da177e4 LT |
1512 | } |
1513 | ||
9287aed2 AG |
1514 | sclass = isec->sclass; |
1515 | task_sid = isec->task_sid; | |
1516 | sid = isec->sid; | |
1517 | isec->initialized = LABEL_PENDING; | |
1518 | spin_unlock(&isec->lock); | |
1519 | ||
1da177e4 | 1520 | switch (sbsec->behavior) { |
eb9ae686 DQ |
1521 | case SECURITY_FS_USE_NATIVE: |
1522 | break; | |
1da177e4 | 1523 | case SECURITY_FS_USE_XATTR: |
5d6c3191 | 1524 | if (!(inode->i_opflags & IOP_XATTR)) { |
9287aed2 | 1525 | sid = sbsec->def_sid; |
1da177e4 LT |
1526 | break; |
1527 | } | |
1da177e4 LT |
1528 | /* Need a dentry, since the xattr API requires one. |
1529 | Life would be simpler if we could just pass the inode. */ | |
1530 | if (opt_dentry) { | |
1531 | /* Called from d_instantiate or d_splice_alias. */ | |
1532 | dentry = dget(opt_dentry); | |
1533 | } else { | |
1534 | /* Called from selinux_complete_init, try to find a dentry. */ | |
1535 | dentry = d_find_alias(inode); | |
1536 | } | |
1537 | if (!dentry) { | |
df7f54c0 EP |
1538 | /* |
1539 | * this is can be hit on boot when a file is accessed | |
1540 | * before the policy is loaded. When we load policy we | |
1541 | * may find inodes that have no dentry on the | |
1542 | * sbsec->isec_head list. No reason to complain as these | |
1543 | * will get fixed up the next time we go through | |
1544 | * inode_doinit with a dentry, before these inodes could | |
1545 | * be used again by userspace. | |
1546 | */ | |
9287aed2 | 1547 | goto out; |
1da177e4 LT |
1548 | } |
1549 | ||
1550 | len = INITCONTEXTLEN; | |
4cb912f1 | 1551 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1552 | if (!context) { |
1553 | rc = -ENOMEM; | |
1554 | dput(dentry); | |
9287aed2 | 1555 | goto out; |
1da177e4 | 1556 | } |
4cb912f1 | 1557 | context[len] = '\0'; |
5d6c3191 | 1558 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 | 1559 | if (rc == -ERANGE) { |
314dabb8 JM |
1560 | kfree(context); |
1561 | ||
1da177e4 | 1562 | /* Need a larger buffer. Query for the right size. */ |
5d6c3191 | 1563 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0); |
1da177e4 LT |
1564 | if (rc < 0) { |
1565 | dput(dentry); | |
9287aed2 | 1566 | goto out; |
1da177e4 | 1567 | } |
1da177e4 | 1568 | len = rc; |
4cb912f1 | 1569 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1570 | if (!context) { |
1571 | rc = -ENOMEM; | |
1572 | dput(dentry); | |
9287aed2 | 1573 | goto out; |
1da177e4 | 1574 | } |
4cb912f1 | 1575 | context[len] = '\0'; |
5d6c3191 | 1576 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 LT |
1577 | } |
1578 | dput(dentry); | |
1579 | if (rc < 0) { | |
1580 | if (rc != -ENODATA) { | |
744ba35e | 1581 | printk(KERN_WARNING "SELinux: %s: getxattr returned " |
dd6f953a | 1582 | "%d for dev=%s ino=%ld\n", __func__, |
1da177e4 LT |
1583 | -rc, inode->i_sb->s_id, inode->i_ino); |
1584 | kfree(context); | |
9287aed2 | 1585 | goto out; |
1da177e4 LT |
1586 | } |
1587 | /* Map ENODATA to the default file SID */ | |
1588 | sid = sbsec->def_sid; | |
1589 | rc = 0; | |
1590 | } else { | |
f5c1d5b2 | 1591 | rc = security_context_to_sid_default(context, rc, &sid, |
869ab514 SS |
1592 | sbsec->def_sid, |
1593 | GFP_NOFS); | |
1da177e4 | 1594 | if (rc) { |
4ba0a8ad EP |
1595 | char *dev = inode->i_sb->s_id; |
1596 | unsigned long ino = inode->i_ino; | |
1597 | ||
1598 | if (rc == -EINVAL) { | |
1599 | if (printk_ratelimit()) | |
1600 | printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " | |
1601 | "context=%s. This indicates you may need to relabel the inode or the " | |
1602 | "filesystem in question.\n", ino, dev, context); | |
1603 | } else { | |
1604 | printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " | |
1605 | "returned %d for dev=%s ino=%ld\n", | |
1606 | __func__, context, -rc, dev, ino); | |
1607 | } | |
1da177e4 LT |
1608 | kfree(context); |
1609 | /* Leave with the unlabeled SID */ | |
1610 | rc = 0; | |
1611 | break; | |
1612 | } | |
1613 | } | |
1614 | kfree(context); | |
1da177e4 LT |
1615 | break; |
1616 | case SECURITY_FS_USE_TASK: | |
9287aed2 | 1617 | sid = task_sid; |
1da177e4 LT |
1618 | break; |
1619 | case SECURITY_FS_USE_TRANS: | |
1620 | /* Default to the fs SID. */ | |
9287aed2 | 1621 | sid = sbsec->sid; |
1da177e4 LT |
1622 | |
1623 | /* Try to obtain a transition SID. */ | |
9287aed2 | 1624 | rc = security_transition_sid(task_sid, sid, sclass, NULL, &sid); |
1da177e4 | 1625 | if (rc) |
9287aed2 | 1626 | goto out; |
1da177e4 | 1627 | break; |
c312feb2 | 1628 | case SECURITY_FS_USE_MNTPOINT: |
9287aed2 | 1629 | sid = sbsec->mntpoint_sid; |
c312feb2 | 1630 | break; |
1da177e4 | 1631 | default: |
c312feb2 | 1632 | /* Default to the fs superblock SID. */ |
9287aed2 | 1633 | sid = sbsec->sid; |
1da177e4 | 1634 | |
134509d5 | 1635 | if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) { |
f64410ec PM |
1636 | /* We must have a dentry to determine the label on |
1637 | * procfs inodes */ | |
1638 | if (opt_dentry) | |
1639 | /* Called from d_instantiate or | |
1640 | * d_splice_alias. */ | |
1641 | dentry = dget(opt_dentry); | |
1642 | else | |
1643 | /* Called from selinux_complete_init, try to | |
1644 | * find a dentry. */ | |
1645 | dentry = d_find_alias(inode); | |
1646 | /* | |
1647 | * This can be hit on boot when a file is accessed | |
1648 | * before the policy is loaded. When we load policy we | |
1649 | * may find inodes that have no dentry on the | |
1650 | * sbsec->isec_head list. No reason to complain as | |
1651 | * these will get fixed up the next time we go through | |
1652 | * inode_doinit() with a dentry, before these inodes | |
1653 | * could be used again by userspace. | |
1654 | */ | |
1655 | if (!dentry) | |
9287aed2 AG |
1656 | goto out; |
1657 | rc = selinux_genfs_get_sid(dentry, sclass, | |
134509d5 | 1658 | sbsec->flags, &sid); |
f64410ec PM |
1659 | dput(dentry); |
1660 | if (rc) | |
9287aed2 | 1661 | goto out; |
1da177e4 LT |
1662 | } |
1663 | break; | |
1664 | } | |
1665 | ||
9287aed2 AG |
1666 | out: |
1667 | spin_lock(&isec->lock); | |
1668 | if (isec->initialized == LABEL_PENDING) { | |
1669 | if (!sid || rc) { | |
1670 | isec->initialized = LABEL_INVALID; | |
1671 | goto out_unlock; | |
1672 | } | |
1673 | ||
1674 | isec->initialized = LABEL_INITIALIZED; | |
1675 | isec->sid = sid; | |
1676 | } | |
1da177e4 | 1677 | |
23970741 | 1678 | out_unlock: |
9287aed2 | 1679 | spin_unlock(&isec->lock); |
1da177e4 LT |
1680 | return rc; |
1681 | } | |
1682 | ||
1683 | /* Convert a Linux signal to an access vector. */ | |
1684 | static inline u32 signal_to_av(int sig) | |
1685 | { | |
1686 | u32 perm = 0; | |
1687 | ||
1688 | switch (sig) { | |
1689 | case SIGCHLD: | |
1690 | /* Commonly granted from child to parent. */ | |
1691 | perm = PROCESS__SIGCHLD; | |
1692 | break; | |
1693 | case SIGKILL: | |
1694 | /* Cannot be caught or ignored */ | |
1695 | perm = PROCESS__SIGKILL; | |
1696 | break; | |
1697 | case SIGSTOP: | |
1698 | /* Cannot be caught or ignored */ | |
1699 | perm = PROCESS__SIGSTOP; | |
1700 | break; | |
1701 | default: | |
1702 | /* All other signals. */ | |
1703 | perm = PROCESS__SIGNAL; | |
1704 | break; | |
1705 | } | |
1706 | ||
1707 | return perm; | |
1708 | } | |
1709 | ||
b68e418c SS |
1710 | #if CAP_LAST_CAP > 63 |
1711 | #error Fix SELinux to handle capabilities > 63. | |
1712 | #endif | |
1713 | ||
1da177e4 | 1714 | /* Check whether a task is allowed to use a capability. */ |
6a9de491 | 1715 | static int cred_has_capability(const struct cred *cred, |
8e4ff6f2 | 1716 | int cap, int audit, bool initns) |
1da177e4 | 1717 | { |
2bf49690 | 1718 | struct common_audit_data ad; |
06112163 | 1719 | struct av_decision avd; |
b68e418c | 1720 | u16 sclass; |
3699c53c | 1721 | u32 sid = cred_sid(cred); |
b68e418c | 1722 | u32 av = CAP_TO_MASK(cap); |
06112163 | 1723 | int rc; |
1da177e4 | 1724 | |
50c205f5 | 1725 | ad.type = LSM_AUDIT_DATA_CAP; |
1da177e4 LT |
1726 | ad.u.cap = cap; |
1727 | ||
b68e418c SS |
1728 | switch (CAP_TO_INDEX(cap)) { |
1729 | case 0: | |
8e4ff6f2 | 1730 | sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS; |
b68e418c SS |
1731 | break; |
1732 | case 1: | |
8e4ff6f2 | 1733 | sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS; |
b68e418c SS |
1734 | break; |
1735 | default: | |
1736 | printk(KERN_ERR | |
1737 | "SELinux: out of range capability %d\n", cap); | |
1738 | BUG(); | |
a35c6c83 | 1739 | return -EINVAL; |
b68e418c | 1740 | } |
06112163 | 1741 | |
275bb41e | 1742 | rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); |
9ade0cf4 | 1743 | if (audit == SECURITY_CAP_AUDIT) { |
7b20ea25 | 1744 | int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0); |
9ade0cf4 EP |
1745 | if (rc2) |
1746 | return rc2; | |
1747 | } | |
06112163 | 1748 | return rc; |
1da177e4 LT |
1749 | } |
1750 | ||
1da177e4 LT |
1751 | /* Check whether a task has a particular permission to an inode. |
1752 | The 'adp' parameter is optional and allows other audit | |
1753 | data to be passed (e.g. the dentry). */ | |
88e67f3b | 1754 | static int inode_has_perm(const struct cred *cred, |
1da177e4 LT |
1755 | struct inode *inode, |
1756 | u32 perms, | |
19e49834 | 1757 | struct common_audit_data *adp) |
1da177e4 | 1758 | { |
1da177e4 | 1759 | struct inode_security_struct *isec; |
275bb41e | 1760 | u32 sid; |
1da177e4 | 1761 | |
e0e81739 DH |
1762 | validate_creds(cred); |
1763 | ||
828dfe1d | 1764 | if (unlikely(IS_PRIVATE(inode))) |
bbaca6c2 SS |
1765 | return 0; |
1766 | ||
88e67f3b | 1767 | sid = cred_sid(cred); |
1da177e4 LT |
1768 | isec = inode->i_security; |
1769 | ||
19e49834 | 1770 | return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp); |
1da177e4 LT |
1771 | } |
1772 | ||
1773 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1774 | the dentry to help the auditing code to more easily generate the | |
1775 | pathname if needed. */ | |
88e67f3b | 1776 | static inline int dentry_has_perm(const struct cred *cred, |
1da177e4 LT |
1777 | struct dentry *dentry, |
1778 | u32 av) | |
1779 | { | |
c6f493d6 | 1780 | struct inode *inode = d_backing_inode(dentry); |
2bf49690 | 1781 | struct common_audit_data ad; |
88e67f3b | 1782 | |
50c205f5 | 1783 | ad.type = LSM_AUDIT_DATA_DENTRY; |
2875fa00 | 1784 | ad.u.dentry = dentry; |
5d226df4 | 1785 | __inode_security_revalidate(inode, dentry, true); |
19e49834 | 1786 | return inode_has_perm(cred, inode, av, &ad); |
2875fa00 EP |
1787 | } |
1788 | ||
1789 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1790 | the path to help the auditing code to more easily generate the | |
1791 | pathname if needed. */ | |
1792 | static inline int path_has_perm(const struct cred *cred, | |
3f7036a0 | 1793 | const struct path *path, |
2875fa00 EP |
1794 | u32 av) |
1795 | { | |
c6f493d6 | 1796 | struct inode *inode = d_backing_inode(path->dentry); |
2875fa00 EP |
1797 | struct common_audit_data ad; |
1798 | ||
50c205f5 | 1799 | ad.type = LSM_AUDIT_DATA_PATH; |
2875fa00 | 1800 | ad.u.path = *path; |
5d226df4 | 1801 | __inode_security_revalidate(inode, path->dentry, true); |
19e49834 | 1802 | return inode_has_perm(cred, inode, av, &ad); |
1da177e4 LT |
1803 | } |
1804 | ||
13f8e981 DH |
1805 | /* Same as path_has_perm, but uses the inode from the file struct. */ |
1806 | static inline int file_path_has_perm(const struct cred *cred, | |
1807 | struct file *file, | |
1808 | u32 av) | |
1809 | { | |
1810 | struct common_audit_data ad; | |
1811 | ||
43af5de7 VG |
1812 | ad.type = LSM_AUDIT_DATA_FILE; |
1813 | ad.u.file = file; | |
19e49834 | 1814 | return inode_has_perm(cred, file_inode(file), av, &ad); |
13f8e981 DH |
1815 | } |
1816 | ||
1da177e4 LT |
1817 | /* Check whether a task can use an open file descriptor to |
1818 | access an inode in a given way. Check access to the | |
1819 | descriptor itself, and then use dentry_has_perm to | |
1820 | check a particular permission to the file. | |
1821 | Access to the descriptor is implicitly granted if it | |
1822 | has the same SID as the process. If av is zero, then | |
1823 | access to the file is not checked, e.g. for cases | |
1824 | where only the descriptor is affected like seek. */ | |
88e67f3b DH |
1825 | static int file_has_perm(const struct cred *cred, |
1826 | struct file *file, | |
1827 | u32 av) | |
1da177e4 | 1828 | { |
1da177e4 | 1829 | struct file_security_struct *fsec = file->f_security; |
496ad9aa | 1830 | struct inode *inode = file_inode(file); |
2bf49690 | 1831 | struct common_audit_data ad; |
88e67f3b | 1832 | u32 sid = cred_sid(cred); |
1da177e4 LT |
1833 | int rc; |
1834 | ||
43af5de7 VG |
1835 | ad.type = LSM_AUDIT_DATA_FILE; |
1836 | ad.u.file = file; | |
1da177e4 | 1837 | |
275bb41e DH |
1838 | if (sid != fsec->sid) { |
1839 | rc = avc_has_perm(sid, fsec->sid, | |
1da177e4 LT |
1840 | SECCLASS_FD, |
1841 | FD__USE, | |
1842 | &ad); | |
1843 | if (rc) | |
88e67f3b | 1844 | goto out; |
1da177e4 LT |
1845 | } |
1846 | ||
1847 | /* av is zero if only checking access to the descriptor. */ | |
88e67f3b | 1848 | rc = 0; |
1da177e4 | 1849 | if (av) |
19e49834 | 1850 | rc = inode_has_perm(cred, inode, av, &ad); |
1da177e4 | 1851 | |
88e67f3b DH |
1852 | out: |
1853 | return rc; | |
1da177e4 LT |
1854 | } |
1855 | ||
c3c188b2 DH |
1856 | /* |
1857 | * Determine the label for an inode that might be unioned. | |
1858 | */ | |
c957f6df VG |
1859 | static int |
1860 | selinux_determine_inode_label(const struct task_security_struct *tsec, | |
1861 | struct inode *dir, | |
1862 | const struct qstr *name, u16 tclass, | |
1863 | u32 *_new_isid) | |
c3c188b2 DH |
1864 | { |
1865 | const struct superblock_security_struct *sbsec = dir->i_sb->s_security; | |
c3c188b2 DH |
1866 | |
1867 | if ((sbsec->flags & SE_SBINITIALIZED) && | |
1868 | (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { | |
1869 | *_new_isid = sbsec->mntpoint_sid; | |
1870 | } else if ((sbsec->flags & SBLABEL_MNT) && | |
1871 | tsec->create_sid) { | |
1872 | *_new_isid = tsec->create_sid; | |
1873 | } else { | |
20cdef8d | 1874 | const struct inode_security_struct *dsec = inode_security(dir); |
c3c188b2 DH |
1875 | return security_transition_sid(tsec->sid, dsec->sid, tclass, |
1876 | name, _new_isid); | |
1877 | } | |
1878 | ||
1879 | return 0; | |
1880 | } | |
1881 | ||
1da177e4 LT |
1882 | /* Check whether a task can create a file. */ |
1883 | static int may_create(struct inode *dir, | |
1884 | struct dentry *dentry, | |
1885 | u16 tclass) | |
1886 | { | |
5fb49870 | 1887 | const struct task_security_struct *tsec = current_security(); |
1da177e4 LT |
1888 | struct inode_security_struct *dsec; |
1889 | struct superblock_security_struct *sbsec; | |
275bb41e | 1890 | u32 sid, newsid; |
2bf49690 | 1891 | struct common_audit_data ad; |
1da177e4 LT |
1892 | int rc; |
1893 | ||
83da53c5 | 1894 | dsec = inode_security(dir); |
1da177e4 LT |
1895 | sbsec = dir->i_sb->s_security; |
1896 | ||
275bb41e | 1897 | sid = tsec->sid; |
275bb41e | 1898 | |
50c205f5 | 1899 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1900 | ad.u.dentry = dentry; |
1da177e4 | 1901 | |
275bb41e | 1902 | rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, |
1da177e4 LT |
1903 | DIR__ADD_NAME | DIR__SEARCH, |
1904 | &ad); | |
1905 | if (rc) | |
1906 | return rc; | |
1907 | ||
c957f6df VG |
1908 | rc = selinux_determine_inode_label(current_security(), dir, |
1909 | &dentry->d_name, tclass, &newsid); | |
c3c188b2 DH |
1910 | if (rc) |
1911 | return rc; | |
1da177e4 | 1912 | |
275bb41e | 1913 | rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); |
1da177e4 LT |
1914 | if (rc) |
1915 | return rc; | |
1916 | ||
1917 | return avc_has_perm(newsid, sbsec->sid, | |
1918 | SECCLASS_FILESYSTEM, | |
1919 | FILESYSTEM__ASSOCIATE, &ad); | |
1920 | } | |
1921 | ||
828dfe1d EP |
1922 | #define MAY_LINK 0 |
1923 | #define MAY_UNLINK 1 | |
1924 | #define MAY_RMDIR 2 | |
1da177e4 LT |
1925 | |
1926 | /* Check whether a task can link, unlink, or rmdir a file/directory. */ | |
1927 | static int may_link(struct inode *dir, | |
1928 | struct dentry *dentry, | |
1929 | int kind) | |
1930 | ||
1931 | { | |
1da177e4 | 1932 | struct inode_security_struct *dsec, *isec; |
2bf49690 | 1933 | struct common_audit_data ad; |
275bb41e | 1934 | u32 sid = current_sid(); |
1da177e4 LT |
1935 | u32 av; |
1936 | int rc; | |
1937 | ||
83da53c5 AG |
1938 | dsec = inode_security(dir); |
1939 | isec = backing_inode_security(dentry); | |
1da177e4 | 1940 | |
50c205f5 | 1941 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1942 | ad.u.dentry = dentry; |
1da177e4 LT |
1943 | |
1944 | av = DIR__SEARCH; | |
1945 | av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); | |
275bb41e | 1946 | rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); |
1da177e4 LT |
1947 | if (rc) |
1948 | return rc; | |
1949 | ||
1950 | switch (kind) { | |
1951 | case MAY_LINK: | |
1952 | av = FILE__LINK; | |
1953 | break; | |
1954 | case MAY_UNLINK: | |
1955 | av = FILE__UNLINK; | |
1956 | break; | |
1957 | case MAY_RMDIR: | |
1958 | av = DIR__RMDIR; | |
1959 | break; | |
1960 | default: | |
744ba35e EP |
1961 | printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", |
1962 | __func__, kind); | |
1da177e4 LT |
1963 | return 0; |
1964 | } | |
1965 | ||
275bb41e | 1966 | rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); |
1da177e4 LT |
1967 | return rc; |
1968 | } | |
1969 | ||
1970 | static inline int may_rename(struct inode *old_dir, | |
1971 | struct dentry *old_dentry, | |
1972 | struct inode *new_dir, | |
1973 | struct dentry *new_dentry) | |
1974 | { | |
1da177e4 | 1975 | struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; |
2bf49690 | 1976 | struct common_audit_data ad; |
275bb41e | 1977 | u32 sid = current_sid(); |
1da177e4 LT |
1978 | u32 av; |
1979 | int old_is_dir, new_is_dir; | |
1980 | int rc; | |
1981 | ||
83da53c5 AG |
1982 | old_dsec = inode_security(old_dir); |
1983 | old_isec = backing_inode_security(old_dentry); | |
e36cb0b8 | 1984 | old_is_dir = d_is_dir(old_dentry); |
83da53c5 | 1985 | new_dsec = inode_security(new_dir); |
1da177e4 | 1986 | |
50c205f5 | 1987 | ad.type = LSM_AUDIT_DATA_DENTRY; |
1da177e4 | 1988 | |
a269434d | 1989 | ad.u.dentry = old_dentry; |
275bb41e | 1990 | rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, |
1da177e4 LT |
1991 | DIR__REMOVE_NAME | DIR__SEARCH, &ad); |
1992 | if (rc) | |
1993 | return rc; | |
275bb41e | 1994 | rc = avc_has_perm(sid, old_isec->sid, |
1da177e4 LT |
1995 | old_isec->sclass, FILE__RENAME, &ad); |
1996 | if (rc) | |
1997 | return rc; | |
1998 | if (old_is_dir && new_dir != old_dir) { | |
275bb41e | 1999 | rc = avc_has_perm(sid, old_isec->sid, |
1da177e4 LT |
2000 | old_isec->sclass, DIR__REPARENT, &ad); |
2001 | if (rc) | |
2002 | return rc; | |
2003 | } | |
2004 | ||
a269434d | 2005 | ad.u.dentry = new_dentry; |
1da177e4 | 2006 | av = DIR__ADD_NAME | DIR__SEARCH; |
2c616d4d | 2007 | if (d_is_positive(new_dentry)) |
1da177e4 | 2008 | av |= DIR__REMOVE_NAME; |
275bb41e | 2009 | rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); |
1da177e4 LT |
2010 | if (rc) |
2011 | return rc; | |
2c616d4d | 2012 | if (d_is_positive(new_dentry)) { |
83da53c5 | 2013 | new_isec = backing_inode_security(new_dentry); |
e36cb0b8 | 2014 | new_is_dir = d_is_dir(new_dentry); |
275bb41e | 2015 | rc = avc_has_perm(sid, new_isec->sid, |
1da177e4 LT |
2016 | new_isec->sclass, |
2017 | (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); | |
2018 | if (rc) | |
2019 | return rc; | |
2020 | } | |
2021 | ||
2022 | return 0; | |
2023 | } | |
2024 | ||
2025 | /* Check whether a task can perform a filesystem operation. */ | |
88e67f3b | 2026 | static int superblock_has_perm(const struct cred *cred, |
1da177e4 LT |
2027 | struct super_block *sb, |
2028 | u32 perms, | |
2bf49690 | 2029 | struct common_audit_data *ad) |
1da177e4 | 2030 | { |
1da177e4 | 2031 | struct superblock_security_struct *sbsec; |
88e67f3b | 2032 | u32 sid = cred_sid(cred); |
1da177e4 | 2033 | |
1da177e4 | 2034 | sbsec = sb->s_security; |
275bb41e | 2035 | return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); |
1da177e4 LT |
2036 | } |
2037 | ||
2038 | /* Convert a Linux mode and permission mask to an access vector. */ | |
2039 | static inline u32 file_mask_to_av(int mode, int mask) | |
2040 | { | |
2041 | u32 av = 0; | |
2042 | ||
dba19c60 | 2043 | if (!S_ISDIR(mode)) { |
1da177e4 LT |
2044 | if (mask & MAY_EXEC) |
2045 | av |= FILE__EXECUTE; | |
2046 | if (mask & MAY_READ) | |
2047 | av |= FILE__READ; | |
2048 | ||
2049 | if (mask & MAY_APPEND) | |
2050 | av |= FILE__APPEND; | |
2051 | else if (mask & MAY_WRITE) | |
2052 | av |= FILE__WRITE; | |
2053 | ||
2054 | } else { | |
2055 | if (mask & MAY_EXEC) | |
2056 | av |= DIR__SEARCH; | |
2057 | if (mask & MAY_WRITE) | |
2058 | av |= DIR__WRITE; | |
2059 | if (mask & MAY_READ) | |
2060 | av |= DIR__READ; | |
2061 | } | |
2062 | ||
2063 | return av; | |
2064 | } | |
2065 | ||
8b6a5a37 EP |
2066 | /* Convert a Linux file to an access vector. */ |
2067 | static inline u32 file_to_av(struct file *file) | |
2068 | { | |
2069 | u32 av = 0; | |
2070 | ||
2071 | if (file->f_mode & FMODE_READ) | |
2072 | av |= FILE__READ; | |
2073 | if (file->f_mode & FMODE_WRITE) { | |
2074 | if (file->f_flags & O_APPEND) | |
2075 | av |= FILE__APPEND; | |
2076 | else | |
2077 | av |= FILE__WRITE; | |
2078 | } | |
2079 | if (!av) { | |
2080 | /* | |
2081 | * Special file opened with flags 3 for ioctl-only use. | |
2082 | */ | |
2083 | av = FILE__IOCTL; | |
2084 | } | |
2085 | ||
2086 | return av; | |
2087 | } | |
2088 | ||
b0c636b9 | 2089 | /* |
8b6a5a37 | 2090 | * Convert a file to an access vector and include the correct open |
b0c636b9 EP |
2091 | * open permission. |
2092 | */ | |
8b6a5a37 | 2093 | static inline u32 open_file_to_av(struct file *file) |
b0c636b9 | 2094 | { |
8b6a5a37 | 2095 | u32 av = file_to_av(file); |
ccb54478 | 2096 | struct inode *inode = file_inode(file); |
b0c636b9 | 2097 | |
ccb54478 | 2098 | if (selinux_policycap_openperm && inode->i_sb->s_magic != SOCKFS_MAGIC) |
49b7b8de EP |
2099 | av |= FILE__OPEN; |
2100 | ||
b0c636b9 EP |
2101 | return av; |
2102 | } | |
2103 | ||
1da177e4 LT |
2104 | /* Hook functions begin here. */ |
2105 | ||
79af7307 SS |
2106 | static int selinux_binder_set_context_mgr(struct task_struct *mgr) |
2107 | { | |
2108 | u32 mysid = current_sid(); | |
2109 | u32 mgrsid = task_sid(mgr); | |
2110 | ||
2111 | return avc_has_perm(mysid, mgrsid, SECCLASS_BINDER, | |
2112 | BINDER__SET_CONTEXT_MGR, NULL); | |
2113 | } | |
2114 | ||
2115 | static int selinux_binder_transaction(struct task_struct *from, | |
2116 | struct task_struct *to) | |
2117 | { | |
2118 | u32 mysid = current_sid(); | |
2119 | u32 fromsid = task_sid(from); | |
2120 | u32 tosid = task_sid(to); | |
2121 | int rc; | |
2122 | ||
2123 | if (mysid != fromsid) { | |
2124 | rc = avc_has_perm(mysid, fromsid, SECCLASS_BINDER, | |
2125 | BINDER__IMPERSONATE, NULL); | |
2126 | if (rc) | |
2127 | return rc; | |
2128 | } | |
2129 | ||
2130 | return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__CALL, | |
2131 | NULL); | |
2132 | } | |
2133 | ||
2134 | static int selinux_binder_transfer_binder(struct task_struct *from, | |
2135 | struct task_struct *to) | |
2136 | { | |
2137 | u32 fromsid = task_sid(from); | |
2138 | u32 tosid = task_sid(to); | |
2139 | ||
2140 | return avc_has_perm(fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER, | |
2141 | NULL); | |
2142 | } | |
2143 | ||
2144 | static int selinux_binder_transfer_file(struct task_struct *from, | |
2145 | struct task_struct *to, | |
2146 | struct file *file) | |
2147 | { | |
2148 | u32 sid = task_sid(to); | |
2149 | struct file_security_struct *fsec = file->f_security; | |
83da53c5 | 2150 | struct dentry *dentry = file->f_path.dentry; |
20cdef8d | 2151 | struct inode_security_struct *isec; |
79af7307 SS |
2152 | struct common_audit_data ad; |
2153 | int rc; | |
2154 | ||
2155 | ad.type = LSM_AUDIT_DATA_PATH; | |
2156 | ad.u.path = file->f_path; | |
2157 | ||
2158 | if (sid != fsec->sid) { | |
2159 | rc = avc_has_perm(sid, fsec->sid, | |
2160 | SECCLASS_FD, | |
2161 | FD__USE, | |
2162 | &ad); | |
2163 | if (rc) | |
2164 | return rc; | |
2165 | } | |
2166 | ||
83da53c5 | 2167 | if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) |
79af7307 SS |
2168 | return 0; |
2169 | ||
20cdef8d | 2170 | isec = backing_inode_security(dentry); |
79af7307 SS |
2171 | return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file), |
2172 | &ad); | |
2173 | } | |
2174 | ||
9e48858f | 2175 | static int selinux_ptrace_access_check(struct task_struct *child, |
5cd9c58f | 2176 | unsigned int mode) |
1da177e4 | 2177 | { |
be0554c9 SS |
2178 | u32 sid = current_sid(); |
2179 | u32 csid = task_sid(child); | |
2180 | ||
2181 | if (mode & PTRACE_MODE_READ) | |
275bb41e | 2182 | return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); |
006ebb40 | 2183 | |
be0554c9 | 2184 | return avc_has_perm(sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL); |
5cd9c58f DH |
2185 | } |
2186 | ||
2187 | static int selinux_ptrace_traceme(struct task_struct *parent) | |
2188 | { | |
be0554c9 SS |
2189 | return avc_has_perm(task_sid(parent), current_sid(), SECCLASS_PROCESS, |
2190 | PROCESS__PTRACE, NULL); | |
1da177e4 LT |
2191 | } |
2192 | ||
2193 | static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, | |
828dfe1d | 2194 | kernel_cap_t *inheritable, kernel_cap_t *permitted) |
1da177e4 | 2195 | { |
be0554c9 SS |
2196 | return avc_has_perm(current_sid(), task_sid(target), SECCLASS_PROCESS, |
2197 | PROCESS__GETCAP, NULL); | |
1da177e4 LT |
2198 | } |
2199 | ||
d84f4f99 DH |
2200 | static int selinux_capset(struct cred *new, const struct cred *old, |
2201 | const kernel_cap_t *effective, | |
2202 | const kernel_cap_t *inheritable, | |
2203 | const kernel_cap_t *permitted) | |
1da177e4 | 2204 | { |
be0554c9 SS |
2205 | return avc_has_perm(cred_sid(old), cred_sid(new), SECCLASS_PROCESS, |
2206 | PROCESS__SETCAP, NULL); | |
1da177e4 LT |
2207 | } |
2208 | ||
5626d3e8 JM |
2209 | /* |
2210 | * (This comment used to live with the selinux_task_setuid hook, | |
2211 | * which was removed). | |
2212 | * | |
2213 | * Since setuid only affects the current process, and since the SELinux | |
2214 | * controls are not based on the Linux identity attributes, SELinux does not | |
2215 | * need to control this operation. However, SELinux does control the use of | |
2216 | * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. | |
2217 | */ | |
2218 | ||
6a9de491 EP |
2219 | static int selinux_capable(const struct cred *cred, struct user_namespace *ns, |
2220 | int cap, int audit) | |
1da177e4 | 2221 | { |
8e4ff6f2 | 2222 | return cred_has_capability(cred, cap, audit, ns == &init_user_ns); |
1da177e4 LT |
2223 | } |
2224 | ||
1da177e4 LT |
2225 | static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) |
2226 | { | |
88e67f3b | 2227 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2228 | int rc = 0; |
2229 | ||
2230 | if (!sb) | |
2231 | return 0; | |
2232 | ||
2233 | switch (cmds) { | |
828dfe1d EP |
2234 | case Q_SYNC: |
2235 | case Q_QUOTAON: | |
2236 | case Q_QUOTAOFF: | |
2237 | case Q_SETINFO: | |
2238 | case Q_SETQUOTA: | |
88e67f3b | 2239 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); |
828dfe1d EP |
2240 | break; |
2241 | case Q_GETFMT: | |
2242 | case Q_GETINFO: | |
2243 | case Q_GETQUOTA: | |
88e67f3b | 2244 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); |
828dfe1d EP |
2245 | break; |
2246 | default: | |
2247 | rc = 0; /* let the kernel handle invalid cmds */ | |
2248 | break; | |
1da177e4 LT |
2249 | } |
2250 | return rc; | |
2251 | } | |
2252 | ||
2253 | static int selinux_quota_on(struct dentry *dentry) | |
2254 | { | |
88e67f3b DH |
2255 | const struct cred *cred = current_cred(); |
2256 | ||
2875fa00 | 2257 | return dentry_has_perm(cred, dentry, FILE__QUOTAON); |
1da177e4 LT |
2258 | } |
2259 | ||
12b3052c | 2260 | static int selinux_syslog(int type) |
1da177e4 | 2261 | { |
1da177e4 | 2262 | switch (type) { |
d78ca3cd KC |
2263 | case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ |
2264 | case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ | |
be0554c9 SS |
2265 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, |
2266 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL); | |
d78ca3cd KC |
2267 | case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ |
2268 | case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ | |
2269 | /* Set level of messages printed to console */ | |
2270 | case SYSLOG_ACTION_CONSOLE_LEVEL: | |
be0554c9 SS |
2271 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, |
2272 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, | |
2273 | NULL); | |
1da177e4 | 2274 | } |
be0554c9 SS |
2275 | /* All other syslog types */ |
2276 | return avc_has_perm(current_sid(), SECINITSID_KERNEL, | |
2277 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL); | |
1da177e4 LT |
2278 | } |
2279 | ||
2280 | /* | |
2281 | * Check that a process has enough memory to allocate a new virtual | |
2282 | * mapping. 0 means there is enough memory for the allocation to | |
2283 | * succeed and -ENOMEM implies there is not. | |
2284 | * | |
1da177e4 LT |
2285 | * Do not audit the selinux permission check, as this is applied to all |
2286 | * processes that allocate mappings. | |
2287 | */ | |
34b4e4aa | 2288 | static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
2289 | { |
2290 | int rc, cap_sys_admin = 0; | |
1da177e4 | 2291 | |
b1d9e6b0 | 2292 | rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN, |
8e4ff6f2 | 2293 | SECURITY_CAP_NOAUDIT, true); |
1da177e4 LT |
2294 | if (rc == 0) |
2295 | cap_sys_admin = 1; | |
2296 | ||
b1d9e6b0 | 2297 | return cap_sys_admin; |
1da177e4 LT |
2298 | } |
2299 | ||
2300 | /* binprm security operations */ | |
2301 | ||
be0554c9 | 2302 | static u32 ptrace_parent_sid(void) |
0c6181cb PM |
2303 | { |
2304 | u32 sid = 0; | |
2305 | struct task_struct *tracer; | |
2306 | ||
2307 | rcu_read_lock(); | |
be0554c9 | 2308 | tracer = ptrace_parent(current); |
0c6181cb PM |
2309 | if (tracer) |
2310 | sid = task_sid(tracer); | |
2311 | rcu_read_unlock(); | |
2312 | ||
2313 | return sid; | |
2314 | } | |
2315 | ||
7b0d0b40 SS |
2316 | static int check_nnp_nosuid(const struct linux_binprm *bprm, |
2317 | const struct task_security_struct *old_tsec, | |
2318 | const struct task_security_struct *new_tsec) | |
2319 | { | |
2320 | int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); | |
380cf5ba | 2321 | int nosuid = !mnt_may_suid(bprm->file->f_path.mnt); |
7b0d0b40 | 2322 | int rc; |
af63f419 | 2323 | u32 av; |
7b0d0b40 SS |
2324 | |
2325 | if (!nnp && !nosuid) | |
2326 | return 0; /* neither NNP nor nosuid */ | |
2327 | ||
2328 | if (new_tsec->sid == old_tsec->sid) | |
2329 | return 0; /* No change in credentials */ | |
2330 | ||
2331 | /* | |
af63f419 SS |
2332 | * If the policy enables the nnp_nosuid_transition policy capability, |
2333 | * then we permit transitions under NNP or nosuid if the | |
2334 | * policy allows the corresponding permission between | |
2335 | * the old and new contexts. | |
7b0d0b40 | 2336 | */ |
af63f419 SS |
2337 | if (selinux_policycap_nnp_nosuid_transition) { |
2338 | av = 0; | |
7b0d0b40 | 2339 | if (nnp) |
af63f419 SS |
2340 | av |= PROCESS2__NNP_TRANSITION; |
2341 | if (nosuid) | |
2342 | av |= PROCESS2__NOSUID_TRANSITION; | |
2343 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, | |
2344 | SECCLASS_PROCESS2, av, NULL); | |
2345 | if (!rc) | |
2346 | return 0; | |
7b0d0b40 | 2347 | } |
af63f419 SS |
2348 | |
2349 | /* | |
2350 | * We also permit NNP or nosuid transitions to bounded SIDs, | |
2351 | * i.e. SIDs that are guaranteed to only be allowed a subset | |
2352 | * of the permissions of the current SID. | |
2353 | */ | |
2354 | rc = security_bounded_transition(old_tsec->sid, new_tsec->sid); | |
2355 | if (!rc) | |
2356 | return 0; | |
2357 | ||
2358 | /* | |
2359 | * On failure, preserve the errno values for NNP vs nosuid. | |
2360 | * NNP: Operation not permitted for caller. | |
2361 | * nosuid: Permission denied to file. | |
2362 | */ | |
2363 | if (nnp) | |
2364 | return -EPERM; | |
2365 | return -EACCES; | |
7b0d0b40 SS |
2366 | } |
2367 | ||
a6f76f23 | 2368 | static int selinux_bprm_set_creds(struct linux_binprm *bprm) |
1da177e4 | 2369 | { |
a6f76f23 DH |
2370 | const struct task_security_struct *old_tsec; |
2371 | struct task_security_struct *new_tsec; | |
1da177e4 | 2372 | struct inode_security_struct *isec; |
2bf49690 | 2373 | struct common_audit_data ad; |
496ad9aa | 2374 | struct inode *inode = file_inode(bprm->file); |
1da177e4 LT |
2375 | int rc; |
2376 | ||
a6f76f23 DH |
2377 | /* SELinux context only depends on initial program or script and not |
2378 | * the script interpreter */ | |
ddb4a144 | 2379 | if (bprm->called_set_creds) |
1da177e4 LT |
2380 | return 0; |
2381 | ||
a6f76f23 DH |
2382 | old_tsec = current_security(); |
2383 | new_tsec = bprm->cred->security; | |
83da53c5 | 2384 | isec = inode_security(inode); |
1da177e4 LT |
2385 | |
2386 | /* Default to the current task SID. */ | |
a6f76f23 DH |
2387 | new_tsec->sid = old_tsec->sid; |
2388 | new_tsec->osid = old_tsec->sid; | |
1da177e4 | 2389 | |
28eba5bf | 2390 | /* Reset fs, key, and sock SIDs on execve. */ |
a6f76f23 DH |
2391 | new_tsec->create_sid = 0; |
2392 | new_tsec->keycreate_sid = 0; | |
2393 | new_tsec->sockcreate_sid = 0; | |
1da177e4 | 2394 | |
a6f76f23 DH |
2395 | if (old_tsec->exec_sid) { |
2396 | new_tsec->sid = old_tsec->exec_sid; | |
1da177e4 | 2397 | /* Reset exec SID on execve. */ |
a6f76f23 | 2398 | new_tsec->exec_sid = 0; |
259e5e6c | 2399 | |
7b0d0b40 SS |
2400 | /* Fail on NNP or nosuid if not an allowed transition. */ |
2401 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2402 | if (rc) | |
2403 | return rc; | |
1da177e4 LT |
2404 | } else { |
2405 | /* Check for a default transition on this program. */ | |
a6f76f23 | 2406 | rc = security_transition_sid(old_tsec->sid, isec->sid, |
652bb9b0 EP |
2407 | SECCLASS_PROCESS, NULL, |
2408 | &new_tsec->sid); | |
1da177e4 LT |
2409 | if (rc) |
2410 | return rc; | |
7b0d0b40 SS |
2411 | |
2412 | /* | |
2413 | * Fallback to old SID on NNP or nosuid if not an allowed | |
2414 | * transition. | |
2415 | */ | |
2416 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2417 | if (rc) | |
2418 | new_tsec->sid = old_tsec->sid; | |
1da177e4 LT |
2419 | } |
2420 | ||
43af5de7 VG |
2421 | ad.type = LSM_AUDIT_DATA_FILE; |
2422 | ad.u.file = bprm->file; | |
1da177e4 | 2423 | |
a6f76f23 DH |
2424 | if (new_tsec->sid == old_tsec->sid) { |
2425 | rc = avc_has_perm(old_tsec->sid, isec->sid, | |
1da177e4 LT |
2426 | SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); |
2427 | if (rc) | |
2428 | return rc; | |
2429 | } else { | |
2430 | /* Check permissions for the transition. */ | |
a6f76f23 | 2431 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, |
1da177e4 LT |
2432 | SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); |
2433 | if (rc) | |
2434 | return rc; | |
2435 | ||
a6f76f23 | 2436 | rc = avc_has_perm(new_tsec->sid, isec->sid, |
1da177e4 LT |
2437 | SECCLASS_FILE, FILE__ENTRYPOINT, &ad); |
2438 | if (rc) | |
2439 | return rc; | |
2440 | ||
a6f76f23 DH |
2441 | /* Check for shared state */ |
2442 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
2443 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, | |
2444 | SECCLASS_PROCESS, PROCESS__SHARE, | |
2445 | NULL); | |
2446 | if (rc) | |
2447 | return -EPERM; | |
2448 | } | |
2449 | ||
2450 | /* Make sure that anyone attempting to ptrace over a task that | |
2451 | * changes its SID has the appropriate permit */ | |
9227dd2a | 2452 | if (bprm->unsafe & LSM_UNSAFE_PTRACE) { |
be0554c9 | 2453 | u32 ptsid = ptrace_parent_sid(); |
a6f76f23 DH |
2454 | if (ptsid != 0) { |
2455 | rc = avc_has_perm(ptsid, new_tsec->sid, | |
2456 | SECCLASS_PROCESS, | |
2457 | PROCESS__PTRACE, NULL); | |
2458 | if (rc) | |
2459 | return -EPERM; | |
2460 | } | |
2461 | } | |
1da177e4 | 2462 | |
a6f76f23 DH |
2463 | /* Clear any possibly unsafe personality bits on exec: */ |
2464 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
275bb41e | 2465 | |
1da177e4 LT |
2466 | /* Enable secure mode for SIDs transitions unless |
2467 | the noatsecure permission is granted between | |
2468 | the two SIDs, i.e. ahp returns 0. */ | |
62874c3a KC |
2469 | rc = avc_has_perm(old_tsec->sid, new_tsec->sid, |
2470 | SECCLASS_PROCESS, PROCESS__NOATSECURE, | |
2471 | NULL); | |
2472 | bprm->secureexec |= !!rc; | |
1da177e4 LT |
2473 | } |
2474 | ||
62874c3a | 2475 | return 0; |
1da177e4 LT |
2476 | } |
2477 | ||
c3c073f8 AV |
2478 | static int match_file(const void *p, struct file *file, unsigned fd) |
2479 | { | |
2480 | return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; | |
2481 | } | |
2482 | ||
1da177e4 | 2483 | /* Derived from fs/exec.c:flush_old_files. */ |
745ca247 DH |
2484 | static inline void flush_unauthorized_files(const struct cred *cred, |
2485 | struct files_struct *files) | |
1da177e4 | 2486 | { |
1da177e4 | 2487 | struct file *file, *devnull = NULL; |
b20c8122 | 2488 | struct tty_struct *tty; |
24ec839c | 2489 | int drop_tty = 0; |
c3c073f8 | 2490 | unsigned n; |
1da177e4 | 2491 | |
24ec839c | 2492 | tty = get_current_tty(); |
1da177e4 | 2493 | if (tty) { |
4a510969 | 2494 | spin_lock(&tty->files_lock); |
37dd0bd0 | 2495 | if (!list_empty(&tty->tty_files)) { |
d996b62a | 2496 | struct tty_file_private *file_priv; |
37dd0bd0 | 2497 | |
1da177e4 | 2498 | /* Revalidate access to controlling tty. |
13f8e981 DH |
2499 | Use file_path_has_perm on the tty path directly |
2500 | rather than using file_has_perm, as this particular | |
2501 | open file may belong to another process and we are | |
2502 | only interested in the inode-based check here. */ | |
d996b62a NP |
2503 | file_priv = list_first_entry(&tty->tty_files, |
2504 | struct tty_file_private, list); | |
2505 | file = file_priv->file; | |
13f8e981 | 2506 | if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE)) |
24ec839c | 2507 | drop_tty = 1; |
1da177e4 | 2508 | } |
4a510969 | 2509 | spin_unlock(&tty->files_lock); |
452a00d2 | 2510 | tty_kref_put(tty); |
1da177e4 | 2511 | } |
98a27ba4 EB |
2512 | /* Reset controlling tty. */ |
2513 | if (drop_tty) | |
2514 | no_tty(); | |
1da177e4 LT |
2515 | |
2516 | /* Revalidate access to inherited open files. */ | |
c3c073f8 AV |
2517 | n = iterate_fd(files, 0, match_file, cred); |
2518 | if (!n) /* none found? */ | |
2519 | return; | |
1da177e4 | 2520 | |
c3c073f8 | 2521 | devnull = dentry_open(&selinux_null, O_RDWR, cred); |
45525b26 AV |
2522 | if (IS_ERR(devnull)) |
2523 | devnull = NULL; | |
2524 | /* replace all the matching ones with this */ | |
2525 | do { | |
2526 | replace_fd(n - 1, devnull, 0); | |
2527 | } while ((n = iterate_fd(files, n, match_file, cred)) != 0); | |
2528 | if (devnull) | |
c3c073f8 | 2529 | fput(devnull); |
1da177e4 LT |
2530 | } |
2531 | ||
a6f76f23 DH |
2532 | /* |
2533 | * Prepare a process for imminent new credential changes due to exec | |
2534 | */ | |
2535 | static void selinux_bprm_committing_creds(struct linux_binprm *bprm) | |
1da177e4 | 2536 | { |
a6f76f23 DH |
2537 | struct task_security_struct *new_tsec; |
2538 | struct rlimit *rlim, *initrlim; | |
2539 | int rc, i; | |
d84f4f99 | 2540 | |
a6f76f23 DH |
2541 | new_tsec = bprm->cred->security; |
2542 | if (new_tsec->sid == new_tsec->osid) | |
2543 | return; | |
1da177e4 | 2544 | |
a6f76f23 DH |
2545 | /* Close files for which the new task SID is not authorized. */ |
2546 | flush_unauthorized_files(bprm->cred, current->files); | |
0356357c | 2547 | |
a6f76f23 DH |
2548 | /* Always clear parent death signal on SID transitions. */ |
2549 | current->pdeath_signal = 0; | |
0356357c | 2550 | |
a6f76f23 DH |
2551 | /* Check whether the new SID can inherit resource limits from the old |
2552 | * SID. If not, reset all soft limits to the lower of the current | |
2553 | * task's hard limit and the init task's soft limit. | |
2554 | * | |
2555 | * Note that the setting of hard limits (even to lower them) can be | |
2556 | * controlled by the setrlimit check. The inclusion of the init task's | |
2557 | * soft limit into the computation is to avoid resetting soft limits | |
2558 | * higher than the default soft limit for cases where the default is | |
2559 | * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. | |
2560 | */ | |
2561 | rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, | |
2562 | PROCESS__RLIMITINH, NULL); | |
2563 | if (rc) { | |
eb2d55a3 ON |
2564 | /* protect against do_prlimit() */ |
2565 | task_lock(current); | |
a6f76f23 DH |
2566 | for (i = 0; i < RLIM_NLIMITS; i++) { |
2567 | rlim = current->signal->rlim + i; | |
2568 | initrlim = init_task.signal->rlim + i; | |
2569 | rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); | |
1da177e4 | 2570 | } |
eb2d55a3 | 2571 | task_unlock(current); |
baa73d9e NP |
2572 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) |
2573 | update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); | |
1da177e4 LT |
2574 | } |
2575 | } | |
2576 | ||
2577 | /* | |
a6f76f23 DH |
2578 | * Clean up the process immediately after the installation of new credentials |
2579 | * due to exec | |
1da177e4 | 2580 | */ |
a6f76f23 | 2581 | static void selinux_bprm_committed_creds(struct linux_binprm *bprm) |
1da177e4 | 2582 | { |
a6f76f23 | 2583 | const struct task_security_struct *tsec = current_security(); |
1da177e4 | 2584 | struct itimerval itimer; |
a6f76f23 | 2585 | u32 osid, sid; |
1da177e4 LT |
2586 | int rc, i; |
2587 | ||
a6f76f23 DH |
2588 | osid = tsec->osid; |
2589 | sid = tsec->sid; | |
2590 | ||
2591 | if (sid == osid) | |
1da177e4 LT |
2592 | return; |
2593 | ||
a6f76f23 DH |
2594 | /* Check whether the new SID can inherit signal state from the old SID. |
2595 | * If not, clear itimers to avoid subsequent signal generation and | |
2596 | * flush and unblock signals. | |
2597 | * | |
2598 | * This must occur _after_ the task SID has been updated so that any | |
2599 | * kill done after the flush will be checked against the new SID. | |
2600 | */ | |
2601 | rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); | |
1da177e4 | 2602 | if (rc) { |
baa73d9e NP |
2603 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) { |
2604 | memset(&itimer, 0, sizeof itimer); | |
2605 | for (i = 0; i < 3; i++) | |
2606 | do_setitimer(i, &itimer, NULL); | |
2607 | } | |
1da177e4 | 2608 | spin_lock_irq(¤t->sighand->siglock); |
9e7c8f8c ON |
2609 | if (!fatal_signal_pending(current)) { |
2610 | flush_sigqueue(¤t->pending); | |
2611 | flush_sigqueue(¤t->signal->shared_pending); | |
3bcac026 DH |
2612 | flush_signal_handlers(current, 1); |
2613 | sigemptyset(¤t->blocked); | |
9e7c8f8c | 2614 | recalc_sigpending(); |
3bcac026 | 2615 | } |
1da177e4 LT |
2616 | spin_unlock_irq(¤t->sighand->siglock); |
2617 | } | |
2618 | ||
a6f76f23 DH |
2619 | /* Wake up the parent if it is waiting so that it can recheck |
2620 | * wait permission to the new task SID. */ | |
ecd6de3c | 2621 | read_lock(&tasklist_lock); |
0b7570e7 | 2622 | __wake_up_parent(current, current->real_parent); |
ecd6de3c | 2623 | read_unlock(&tasklist_lock); |
1da177e4 LT |
2624 | } |
2625 | ||
2626 | /* superblock security operations */ | |
2627 | ||
2628 | static int selinux_sb_alloc_security(struct super_block *sb) | |
2629 | { | |
2630 | return superblock_alloc_security(sb); | |
2631 | } | |
2632 | ||
2633 | static void selinux_sb_free_security(struct super_block *sb) | |
2634 | { | |
2635 | superblock_free_security(sb); | |
2636 | } | |
2637 | ||
2638 | static inline int match_prefix(char *prefix, int plen, char *option, int olen) | |
2639 | { | |
2640 | if (plen > olen) | |
2641 | return 0; | |
2642 | ||
2643 | return !memcmp(prefix, option, plen); | |
2644 | } | |
2645 | ||
2646 | static inline int selinux_option(char *option, int len) | |
2647 | { | |
832cbd9a EP |
2648 | return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || |
2649 | match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || | |
2650 | match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || | |
11689d47 DQ |
2651 | match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || |
2652 | match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); | |
1da177e4 LT |
2653 | } |
2654 | ||
2655 | static inline void take_option(char **to, char *from, int *first, int len) | |
2656 | { | |
2657 | if (!*first) { | |
2658 | **to = ','; | |
2659 | *to += 1; | |
3528a953 | 2660 | } else |
1da177e4 LT |
2661 | *first = 0; |
2662 | memcpy(*to, from, len); | |
2663 | *to += len; | |
2664 | } | |
2665 | ||
828dfe1d EP |
2666 | static inline void take_selinux_option(char **to, char *from, int *first, |
2667 | int len) | |
3528a953 CO |
2668 | { |
2669 | int current_size = 0; | |
2670 | ||
2671 | if (!*first) { | |
2672 | **to = '|'; | |
2673 | *to += 1; | |
828dfe1d | 2674 | } else |
3528a953 CO |
2675 | *first = 0; |
2676 | ||
2677 | while (current_size < len) { | |
2678 | if (*from != '"') { | |
2679 | **to = *from; | |
2680 | *to += 1; | |
2681 | } | |
2682 | from += 1; | |
2683 | current_size += 1; | |
2684 | } | |
2685 | } | |
2686 | ||
e0007529 | 2687 | static int selinux_sb_copy_data(char *orig, char *copy) |
1da177e4 LT |
2688 | { |
2689 | int fnosec, fsec, rc = 0; | |
2690 | char *in_save, *in_curr, *in_end; | |
2691 | char *sec_curr, *nosec_save, *nosec; | |
3528a953 | 2692 | int open_quote = 0; |
1da177e4 LT |
2693 | |
2694 | in_curr = orig; | |
2695 | sec_curr = copy; | |
2696 | ||
1da177e4 LT |
2697 | nosec = (char *)get_zeroed_page(GFP_KERNEL); |
2698 | if (!nosec) { | |
2699 | rc = -ENOMEM; | |
2700 | goto out; | |
2701 | } | |
2702 | ||
2703 | nosec_save = nosec; | |
2704 | fnosec = fsec = 1; | |
2705 | in_save = in_end = orig; | |
2706 | ||
2707 | do { | |
3528a953 CO |
2708 | if (*in_end == '"') |
2709 | open_quote = !open_quote; | |
2710 | if ((*in_end == ',' && open_quote == 0) || | |
2711 | *in_end == '\0') { | |
1da177e4 LT |
2712 | int len = in_end - in_curr; |
2713 | ||
2714 | if (selinux_option(in_curr, len)) | |
3528a953 | 2715 | take_selinux_option(&sec_curr, in_curr, &fsec, len); |
1da177e4 LT |
2716 | else |
2717 | take_option(&nosec, in_curr, &fnosec, len); | |
2718 | ||
2719 | in_curr = in_end + 1; | |
2720 | } | |
2721 | } while (*in_end++); | |
2722 | ||
6931dfc9 | 2723 | strcpy(in_save, nosec_save); |
da3caa20 | 2724 | free_page((unsigned long)nosec_save); |
1da177e4 LT |
2725 | out: |
2726 | return rc; | |
2727 | } | |
2728 | ||
026eb167 EP |
2729 | static int selinux_sb_remount(struct super_block *sb, void *data) |
2730 | { | |
2731 | int rc, i, *flags; | |
2732 | struct security_mnt_opts opts; | |
2733 | char *secdata, **mount_options; | |
2734 | struct superblock_security_struct *sbsec = sb->s_security; | |
2735 | ||
2736 | if (!(sbsec->flags & SE_SBINITIALIZED)) | |
2737 | return 0; | |
2738 | ||
2739 | if (!data) | |
2740 | return 0; | |
2741 | ||
2742 | if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) | |
2743 | return 0; | |
2744 | ||
2745 | security_init_mnt_opts(&opts); | |
2746 | secdata = alloc_secdata(); | |
2747 | if (!secdata) | |
2748 | return -ENOMEM; | |
2749 | rc = selinux_sb_copy_data(data, secdata); | |
2750 | if (rc) | |
2751 | goto out_free_secdata; | |
2752 | ||
2753 | rc = selinux_parse_opts_str(secdata, &opts); | |
2754 | if (rc) | |
2755 | goto out_free_secdata; | |
2756 | ||
2757 | mount_options = opts.mnt_opts; | |
2758 | flags = opts.mnt_opts_flags; | |
2759 | ||
2760 | for (i = 0; i < opts.num_mnt_opts; i++) { | |
2761 | u32 sid; | |
026eb167 | 2762 | |
12f348b9 | 2763 | if (flags[i] == SBLABEL_MNT) |
026eb167 | 2764 | continue; |
44be2f65 | 2765 | rc = security_context_str_to_sid(mount_options[i], &sid, GFP_KERNEL); |
026eb167 | 2766 | if (rc) { |
44be2f65 | 2767 | printk(KERN_WARNING "SELinux: security_context_str_to_sid" |
29b1deb2 LT |
2768 | "(%s) failed for (dev %s, type %s) errno=%d\n", |
2769 | mount_options[i], sb->s_id, sb->s_type->name, rc); | |
026eb167 EP |
2770 | goto out_free_opts; |
2771 | } | |
2772 | rc = -EINVAL; | |
2773 | switch (flags[i]) { | |
2774 | case FSCONTEXT_MNT: | |
2775 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) | |
2776 | goto out_bad_option; | |
2777 | break; | |
2778 | case CONTEXT_MNT: | |
2779 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) | |
2780 | goto out_bad_option; | |
2781 | break; | |
2782 | case ROOTCONTEXT_MNT: { | |
2783 | struct inode_security_struct *root_isec; | |
83da53c5 | 2784 | root_isec = backing_inode_security(sb->s_root); |
026eb167 EP |
2785 | |
2786 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) | |
2787 | goto out_bad_option; | |
2788 | break; | |
2789 | } | |
2790 | case DEFCONTEXT_MNT: | |
2791 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) | |
2792 | goto out_bad_option; | |
2793 | break; | |
2794 | default: | |
2795 | goto out_free_opts; | |
2796 | } | |
2797 | } | |
2798 | ||
2799 | rc = 0; | |
2800 | out_free_opts: | |
2801 | security_free_mnt_opts(&opts); | |
2802 | out_free_secdata: | |
2803 | free_secdata(secdata); | |
2804 | return rc; | |
2805 | out_bad_option: | |
2806 | printk(KERN_WARNING "SELinux: unable to change security options " | |
29b1deb2 LT |
2807 | "during remount (dev %s, type=%s)\n", sb->s_id, |
2808 | sb->s_type->name); | |
026eb167 EP |
2809 | goto out_free_opts; |
2810 | } | |
2811 | ||
12204e24 | 2812 | static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) |
1da177e4 | 2813 | { |
88e67f3b | 2814 | const struct cred *cred = current_cred(); |
2bf49690 | 2815 | struct common_audit_data ad; |
1da177e4 LT |
2816 | int rc; |
2817 | ||
2818 | rc = superblock_doinit(sb, data); | |
2819 | if (rc) | |
2820 | return rc; | |
2821 | ||
74192246 JM |
2822 | /* Allow all mounts performed by the kernel */ |
2823 | if (flags & MS_KERNMOUNT) | |
2824 | return 0; | |
2825 | ||
50c205f5 | 2826 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2827 | ad.u.dentry = sb->s_root; |
88e67f3b | 2828 | return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); |
1da177e4 LT |
2829 | } |
2830 | ||
726c3342 | 2831 | static int selinux_sb_statfs(struct dentry *dentry) |
1da177e4 | 2832 | { |
88e67f3b | 2833 | const struct cred *cred = current_cred(); |
2bf49690 | 2834 | struct common_audit_data ad; |
1da177e4 | 2835 | |
50c205f5 | 2836 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2837 | ad.u.dentry = dentry->d_sb->s_root; |
88e67f3b | 2838 | return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); |
1da177e4 LT |
2839 | } |
2840 | ||
808d4e3c | 2841 | static int selinux_mount(const char *dev_name, |
8a04c43b | 2842 | const struct path *path, |
808d4e3c | 2843 | const char *type, |
828dfe1d EP |
2844 | unsigned long flags, |
2845 | void *data) | |
1da177e4 | 2846 | { |
88e67f3b | 2847 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2848 | |
2849 | if (flags & MS_REMOUNT) | |
d8c9584e | 2850 | return superblock_has_perm(cred, path->dentry->d_sb, |
828dfe1d | 2851 | FILESYSTEM__REMOUNT, NULL); |
1da177e4 | 2852 | else |
2875fa00 | 2853 | return path_has_perm(cred, path, FILE__MOUNTON); |
1da177e4 LT |
2854 | } |
2855 | ||
2856 | static int selinux_umount(struct vfsmount *mnt, int flags) | |
2857 | { | |
88e67f3b | 2858 | const struct cred *cred = current_cred(); |
1da177e4 | 2859 | |
88e67f3b | 2860 | return superblock_has_perm(cred, mnt->mnt_sb, |
828dfe1d | 2861 | FILESYSTEM__UNMOUNT, NULL); |
1da177e4 LT |
2862 | } |
2863 | ||
2864 | /* inode security operations */ | |
2865 | ||
2866 | static int selinux_inode_alloc_security(struct inode *inode) | |
2867 | { | |
2868 | return inode_alloc_security(inode); | |
2869 | } | |
2870 | ||
2871 | static void selinux_inode_free_security(struct inode *inode) | |
2872 | { | |
2873 | inode_free_security(inode); | |
2874 | } | |
2875 | ||
d47be3df | 2876 | static int selinux_dentry_init_security(struct dentry *dentry, int mode, |
4f3ccd76 | 2877 | const struct qstr *name, void **ctx, |
d47be3df DQ |
2878 | u32 *ctxlen) |
2879 | { | |
d47be3df DQ |
2880 | u32 newsid; |
2881 | int rc; | |
2882 | ||
c957f6df VG |
2883 | rc = selinux_determine_inode_label(current_security(), |
2884 | d_inode(dentry->d_parent), name, | |
c3c188b2 DH |
2885 | inode_mode_to_security_class(mode), |
2886 | &newsid); | |
2887 | if (rc) | |
2888 | return rc; | |
d47be3df DQ |
2889 | |
2890 | return security_sid_to_context(newsid, (char **)ctx, ctxlen); | |
2891 | } | |
2892 | ||
a518b0a5 VG |
2893 | static int selinux_dentry_create_files_as(struct dentry *dentry, int mode, |
2894 | struct qstr *name, | |
2895 | const struct cred *old, | |
2896 | struct cred *new) | |
2897 | { | |
2898 | u32 newsid; | |
2899 | int rc; | |
2900 | struct task_security_struct *tsec; | |
2901 | ||
2902 | rc = selinux_determine_inode_label(old->security, | |
2903 | d_inode(dentry->d_parent), name, | |
2904 | inode_mode_to_security_class(mode), | |
2905 | &newsid); | |
2906 | if (rc) | |
2907 | return rc; | |
2908 | ||
2909 | tsec = new->security; | |
2910 | tsec->create_sid = newsid; | |
2911 | return 0; | |
2912 | } | |
2913 | ||
5e41ff9e | 2914 | static int selinux_inode_init_security(struct inode *inode, struct inode *dir, |
9548906b TH |
2915 | const struct qstr *qstr, |
2916 | const char **name, | |
2a7dba39 | 2917 | void **value, size_t *len) |
5e41ff9e | 2918 | { |
5fb49870 | 2919 | const struct task_security_struct *tsec = current_security(); |
5e41ff9e | 2920 | struct superblock_security_struct *sbsec; |
275bb41e | 2921 | u32 sid, newsid, clen; |
5e41ff9e | 2922 | int rc; |
9548906b | 2923 | char *context; |
5e41ff9e | 2924 | |
5e41ff9e | 2925 | sbsec = dir->i_sb->s_security; |
5e41ff9e | 2926 | |
275bb41e DH |
2927 | sid = tsec->sid; |
2928 | newsid = tsec->create_sid; | |
2929 | ||
c957f6df | 2930 | rc = selinux_determine_inode_label(current_security(), |
c3c188b2 DH |
2931 | dir, qstr, |
2932 | inode_mode_to_security_class(inode->i_mode), | |
2933 | &newsid); | |
2934 | if (rc) | |
2935 | return rc; | |
5e41ff9e | 2936 | |
296fddf7 | 2937 | /* Possibly defer initialization to selinux_complete_init. */ |
0d90a7ec | 2938 | if (sbsec->flags & SE_SBINITIALIZED) { |
296fddf7 EP |
2939 | struct inode_security_struct *isec = inode->i_security; |
2940 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
2941 | isec->sid = newsid; | |
6f3be9f5 | 2942 | isec->initialized = LABEL_INITIALIZED; |
296fddf7 | 2943 | } |
5e41ff9e | 2944 | |
12f348b9 | 2945 | if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT)) |
25a74f3b SS |
2946 | return -EOPNOTSUPP; |
2947 | ||
9548906b TH |
2948 | if (name) |
2949 | *name = XATTR_SELINUX_SUFFIX; | |
5e41ff9e | 2950 | |
570bc1c2 | 2951 | if (value && len) { |
12b29f34 | 2952 | rc = security_sid_to_context_force(newsid, &context, &clen); |
9548906b | 2953 | if (rc) |
570bc1c2 | 2954 | return rc; |
570bc1c2 SS |
2955 | *value = context; |
2956 | *len = clen; | |
5e41ff9e | 2957 | } |
5e41ff9e | 2958 | |
5e41ff9e SS |
2959 | return 0; |
2960 | } | |
2961 | ||
4acdaf27 | 2962 | static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
2963 | { |
2964 | return may_create(dir, dentry, SECCLASS_FILE); | |
2965 | } | |
2966 | ||
1da177e4 LT |
2967 | static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) |
2968 | { | |
1da177e4 LT |
2969 | return may_link(dir, old_dentry, MAY_LINK); |
2970 | } | |
2971 | ||
1da177e4 LT |
2972 | static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) |
2973 | { | |
1da177e4 LT |
2974 | return may_link(dir, dentry, MAY_UNLINK); |
2975 | } | |
2976 | ||
2977 | static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) | |
2978 | { | |
2979 | return may_create(dir, dentry, SECCLASS_LNK_FILE); | |
2980 | } | |
2981 | ||
18bb1db3 | 2982 | static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) |
1da177e4 LT |
2983 | { |
2984 | return may_create(dir, dentry, SECCLASS_DIR); | |
2985 | } | |
2986 | ||
1da177e4 LT |
2987 | static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) |
2988 | { | |
2989 | return may_link(dir, dentry, MAY_RMDIR); | |
2990 | } | |
2991 | ||
1a67aafb | 2992 | static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 | 2993 | { |
1da177e4 LT |
2994 | return may_create(dir, dentry, inode_mode_to_security_class(mode)); |
2995 | } | |
2996 | ||
1da177e4 | 2997 | static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, |
828dfe1d | 2998 | struct inode *new_inode, struct dentry *new_dentry) |
1da177e4 LT |
2999 | { |
3000 | return may_rename(old_inode, old_dentry, new_inode, new_dentry); | |
3001 | } | |
3002 | ||
1da177e4 LT |
3003 | static int selinux_inode_readlink(struct dentry *dentry) |
3004 | { | |
88e67f3b DH |
3005 | const struct cred *cred = current_cred(); |
3006 | ||
2875fa00 | 3007 | return dentry_has_perm(cred, dentry, FILE__READ); |
1da177e4 LT |
3008 | } |
3009 | ||
bda0be7a N |
3010 | static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, |
3011 | bool rcu) | |
1da177e4 | 3012 | { |
88e67f3b | 3013 | const struct cred *cred = current_cred(); |
bda0be7a N |
3014 | struct common_audit_data ad; |
3015 | struct inode_security_struct *isec; | |
3016 | u32 sid; | |
1da177e4 | 3017 | |
bda0be7a N |
3018 | validate_creds(cred); |
3019 | ||
3020 | ad.type = LSM_AUDIT_DATA_DENTRY; | |
3021 | ad.u.dentry = dentry; | |
3022 | sid = cred_sid(cred); | |
5d226df4 AG |
3023 | isec = inode_security_rcu(inode, rcu); |
3024 | if (IS_ERR(isec)) | |
3025 | return PTR_ERR(isec); | |
bda0be7a N |
3026 | |
3027 | return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad, | |
3028 | rcu ? MAY_NOT_BLOCK : 0); | |
1da177e4 LT |
3029 | } |
3030 | ||
d4cf970d EP |
3031 | static noinline int audit_inode_permission(struct inode *inode, |
3032 | u32 perms, u32 audited, u32 denied, | |
626b9740 | 3033 | int result, |
d4cf970d | 3034 | unsigned flags) |
1da177e4 | 3035 | { |
b782e0a6 | 3036 | struct common_audit_data ad; |
d4cf970d EP |
3037 | struct inode_security_struct *isec = inode->i_security; |
3038 | int rc; | |
3039 | ||
50c205f5 | 3040 | ad.type = LSM_AUDIT_DATA_INODE; |
d4cf970d EP |
3041 | ad.u.inode = inode; |
3042 | ||
3043 | rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms, | |
626b9740 | 3044 | audited, denied, result, &ad, flags); |
d4cf970d EP |
3045 | if (rc) |
3046 | return rc; | |
3047 | return 0; | |
3048 | } | |
3049 | ||
e74f71eb | 3050 | static int selinux_inode_permission(struct inode *inode, int mask) |
1da177e4 | 3051 | { |
88e67f3b | 3052 | const struct cred *cred = current_cred(); |
b782e0a6 EP |
3053 | u32 perms; |
3054 | bool from_access; | |
cf1dd1da | 3055 | unsigned flags = mask & MAY_NOT_BLOCK; |
2e334057 EP |
3056 | struct inode_security_struct *isec; |
3057 | u32 sid; | |
3058 | struct av_decision avd; | |
3059 | int rc, rc2; | |
3060 | u32 audited, denied; | |
1da177e4 | 3061 | |
b782e0a6 | 3062 | from_access = mask & MAY_ACCESS; |
d09ca739 EP |
3063 | mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
3064 | ||
b782e0a6 EP |
3065 | /* No permission to check. Existence test. */ |
3066 | if (!mask) | |
1da177e4 | 3067 | return 0; |
1da177e4 | 3068 | |
2e334057 | 3069 | validate_creds(cred); |
b782e0a6 | 3070 | |
2e334057 EP |
3071 | if (unlikely(IS_PRIVATE(inode))) |
3072 | return 0; | |
b782e0a6 EP |
3073 | |
3074 | perms = file_mask_to_av(inode->i_mode, mask); | |
3075 | ||
2e334057 | 3076 | sid = cred_sid(cred); |
5d226df4 AG |
3077 | isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK); |
3078 | if (IS_ERR(isec)) | |
3079 | return PTR_ERR(isec); | |
2e334057 EP |
3080 | |
3081 | rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd); | |
3082 | audited = avc_audit_required(perms, &avd, rc, | |
3083 | from_access ? FILE__AUDIT_ACCESS : 0, | |
3084 | &denied); | |
3085 | if (likely(!audited)) | |
3086 | return rc; | |
3087 | ||
626b9740 | 3088 | rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags); |
2e334057 EP |
3089 | if (rc2) |
3090 | return rc2; | |
3091 | return rc; | |
1da177e4 LT |
3092 | } |
3093 | ||
3094 | static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
3095 | { | |
88e67f3b | 3096 | const struct cred *cred = current_cred(); |
ccb54478 | 3097 | struct inode *inode = d_backing_inode(dentry); |
bc6a6008 | 3098 | unsigned int ia_valid = iattr->ia_valid; |
95dbf739 | 3099 | __u32 av = FILE__WRITE; |
1da177e4 | 3100 | |
bc6a6008 AW |
3101 | /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ |
3102 | if (ia_valid & ATTR_FORCE) { | |
3103 | ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | | |
3104 | ATTR_FORCE); | |
3105 | if (!ia_valid) | |
3106 | return 0; | |
3107 | } | |
1da177e4 | 3108 | |
bc6a6008 AW |
3109 | if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | |
3110 | ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) | |
2875fa00 | 3111 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
1da177e4 | 3112 | |
ccb54478 SS |
3113 | if (selinux_policycap_openperm && |
3114 | inode->i_sb->s_magic != SOCKFS_MAGIC && | |
3115 | (ia_valid & ATTR_SIZE) && | |
3116 | !(ia_valid & ATTR_FILE)) | |
95dbf739 EP |
3117 | av |= FILE__OPEN; |
3118 | ||
3119 | return dentry_has_perm(cred, dentry, av); | |
1da177e4 LT |
3120 | } |
3121 | ||
3f7036a0 | 3122 | static int selinux_inode_getattr(const struct path *path) |
1da177e4 | 3123 | { |
3f7036a0 | 3124 | return path_has_perm(current_cred(), path, FILE__GETATTR); |
1da177e4 LT |
3125 | } |
3126 | ||
db59000a SS |
3127 | static bool has_cap_mac_admin(bool audit) |
3128 | { | |
3129 | const struct cred *cred = current_cred(); | |
3130 | int cap_audit = audit ? SECURITY_CAP_AUDIT : SECURITY_CAP_NOAUDIT; | |
3131 | ||
3132 | if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, cap_audit)) | |
3133 | return false; | |
3134 | if (cred_has_capability(cred, CAP_MAC_ADMIN, cap_audit, true)) | |
3135 | return false; | |
3136 | return true; | |
3137 | } | |
3138 | ||
8f0cfa52 DH |
3139 | static int selinux_inode_setxattr(struct dentry *dentry, const char *name, |
3140 | const void *value, size_t size, int flags) | |
1da177e4 | 3141 | { |
c6f493d6 | 3142 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3143 | struct inode_security_struct *isec; |
1da177e4 | 3144 | struct superblock_security_struct *sbsec; |
2bf49690 | 3145 | struct common_audit_data ad; |
275bb41e | 3146 | u32 newsid, sid = current_sid(); |
1da177e4 LT |
3147 | int rc = 0; |
3148 | ||
6b240306 EB |
3149 | if (strcmp(name, XATTR_NAME_SELINUX)) { |
3150 | rc = cap_inode_setxattr(dentry, name, value, size, flags); | |
3151 | if (rc) | |
3152 | return rc; | |
3153 | ||
3154 | /* Not an attribute we recognize, so just check the | |
3155 | ordinary setattr permission. */ | |
3156 | return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); | |
3157 | } | |
1da177e4 LT |
3158 | |
3159 | sbsec = inode->i_sb->s_security; | |
12f348b9 | 3160 | if (!(sbsec->flags & SBLABEL_MNT)) |
1da177e4 LT |
3161 | return -EOPNOTSUPP; |
3162 | ||
2e149670 | 3163 | if (!inode_owner_or_capable(inode)) |
1da177e4 LT |
3164 | return -EPERM; |
3165 | ||
50c205f5 | 3166 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 3167 | ad.u.dentry = dentry; |
1da177e4 | 3168 | |
20cdef8d | 3169 | isec = backing_inode_security(dentry); |
275bb41e | 3170 | rc = avc_has_perm(sid, isec->sid, isec->sclass, |
1da177e4 LT |
3171 | FILE__RELABELFROM, &ad); |
3172 | if (rc) | |
3173 | return rc; | |
3174 | ||
52a4c640 | 3175 | rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL); |
12b29f34 | 3176 | if (rc == -EINVAL) { |
db59000a | 3177 | if (!has_cap_mac_admin(true)) { |
d6ea83ec EP |
3178 | struct audit_buffer *ab; |
3179 | size_t audit_size; | |
3180 | const char *str; | |
3181 | ||
3182 | /* We strip a nul only if it is at the end, otherwise the | |
3183 | * context contains a nul and we should audit that */ | |
e3fea3f7 AV |
3184 | if (value) { |
3185 | str = value; | |
3186 | if (str[size - 1] == '\0') | |
3187 | audit_size = size - 1; | |
3188 | else | |
3189 | audit_size = size; | |
3190 | } else { | |
3191 | str = ""; | |
3192 | audit_size = 0; | |
3193 | } | |
d6ea83ec EP |
3194 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR); |
3195 | audit_log_format(ab, "op=setxattr invalid_context="); | |
3196 | audit_log_n_untrustedstring(ab, value, audit_size); | |
3197 | audit_log_end(ab); | |
3198 | ||
12b29f34 | 3199 | return rc; |
d6ea83ec | 3200 | } |
12b29f34 SS |
3201 | rc = security_context_to_sid_force(value, size, &newsid); |
3202 | } | |
1da177e4 LT |
3203 | if (rc) |
3204 | return rc; | |
3205 | ||
275bb41e | 3206 | rc = avc_has_perm(sid, newsid, isec->sclass, |
1da177e4 LT |
3207 | FILE__RELABELTO, &ad); |
3208 | if (rc) | |
3209 | return rc; | |
3210 | ||
275bb41e | 3211 | rc = security_validate_transition(isec->sid, newsid, sid, |
828dfe1d | 3212 | isec->sclass); |
1da177e4 LT |
3213 | if (rc) |
3214 | return rc; | |
3215 | ||
3216 | return avc_has_perm(newsid, | |
3217 | sbsec->sid, | |
3218 | SECCLASS_FILESYSTEM, | |
3219 | FILESYSTEM__ASSOCIATE, | |
3220 | &ad); | |
3221 | } | |
3222 | ||
8f0cfa52 | 3223 | static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, |
f5269710 | 3224 | const void *value, size_t size, |
8f0cfa52 | 3225 | int flags) |
1da177e4 | 3226 | { |
c6f493d6 | 3227 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3228 | struct inode_security_struct *isec; |
1da177e4 LT |
3229 | u32 newsid; |
3230 | int rc; | |
3231 | ||
3232 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
3233 | /* Not an attribute we recognize, so nothing to do. */ | |
3234 | return; | |
3235 | } | |
3236 | ||
12b29f34 | 3237 | rc = security_context_to_sid_force(value, size, &newsid); |
1da177e4 | 3238 | if (rc) { |
12b29f34 SS |
3239 | printk(KERN_ERR "SELinux: unable to map context to SID" |
3240 | "for (%s, %lu), rc=%d\n", | |
3241 | inode->i_sb->s_id, inode->i_ino, -rc); | |
1da177e4 LT |
3242 | return; |
3243 | } | |
3244 | ||
20cdef8d | 3245 | isec = backing_inode_security(dentry); |
9287aed2 | 3246 | spin_lock(&isec->lock); |
aa9c2669 | 3247 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3248 | isec->sid = newsid; |
6f3be9f5 | 3249 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3250 | spin_unlock(&isec->lock); |
aa9c2669 | 3251 | |
1da177e4 LT |
3252 | return; |
3253 | } | |
3254 | ||
8f0cfa52 | 3255 | static int selinux_inode_getxattr(struct dentry *dentry, const char *name) |
1da177e4 | 3256 | { |
88e67f3b DH |
3257 | const struct cred *cred = current_cred(); |
3258 | ||
2875fa00 | 3259 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3260 | } |
3261 | ||
828dfe1d | 3262 | static int selinux_inode_listxattr(struct dentry *dentry) |
1da177e4 | 3263 | { |
88e67f3b DH |
3264 | const struct cred *cred = current_cred(); |
3265 | ||
2875fa00 | 3266 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3267 | } |
3268 | ||
8f0cfa52 | 3269 | static int selinux_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 3270 | { |
6b240306 EB |
3271 | if (strcmp(name, XATTR_NAME_SELINUX)) { |
3272 | int rc = cap_inode_removexattr(dentry, name); | |
3273 | if (rc) | |
3274 | return rc; | |
3275 | ||
3276 | /* Not an attribute we recognize, so just check the | |
3277 | ordinary setattr permission. */ | |
3278 | return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); | |
3279 | } | |
1da177e4 LT |
3280 | |
3281 | /* No one is allowed to remove a SELinux security label. | |
3282 | You can change the label, but all data must be labeled. */ | |
3283 | return -EACCES; | |
3284 | } | |
3285 | ||
d381d8a9 | 3286 | /* |
abc69bb6 | 3287 | * Copy the inode security context value to the user. |
d381d8a9 JM |
3288 | * |
3289 | * Permission check is handled by selinux_inode_getxattr hook. | |
3290 | */ | |
ea861dfd | 3291 | static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc) |
1da177e4 | 3292 | { |
42492594 DQ |
3293 | u32 size; |
3294 | int error; | |
3295 | char *context = NULL; | |
20cdef8d | 3296 | struct inode_security_struct *isec; |
d381d8a9 | 3297 | |
8c8570fb DK |
3298 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) |
3299 | return -EOPNOTSUPP; | |
d381d8a9 | 3300 | |
abc69bb6 SS |
3301 | /* |
3302 | * If the caller has CAP_MAC_ADMIN, then get the raw context | |
3303 | * value even if it is not defined by current policy; otherwise, | |
3304 | * use the in-core value under current policy. | |
3305 | * Use the non-auditing forms of the permission checks since | |
3306 | * getxattr may be called by unprivileged processes commonly | |
3307 | * and lack of permission just means that we fall back to the | |
3308 | * in-core context value, not a denial. | |
3309 | */ | |
20cdef8d | 3310 | isec = inode_security(inode); |
db59000a | 3311 | if (has_cap_mac_admin(false)) |
abc69bb6 SS |
3312 | error = security_sid_to_context_force(isec->sid, &context, |
3313 | &size); | |
3314 | else | |
3315 | error = security_sid_to_context(isec->sid, &context, &size); | |
42492594 DQ |
3316 | if (error) |
3317 | return error; | |
3318 | error = size; | |
3319 | if (alloc) { | |
3320 | *buffer = context; | |
3321 | goto out_nofree; | |
3322 | } | |
3323 | kfree(context); | |
3324 | out_nofree: | |
3325 | return error; | |
1da177e4 LT |
3326 | } |
3327 | ||
3328 | static int selinux_inode_setsecurity(struct inode *inode, const char *name, | |
828dfe1d | 3329 | const void *value, size_t size, int flags) |
1da177e4 | 3330 | { |
2c97165b | 3331 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
1da177e4 LT |
3332 | u32 newsid; |
3333 | int rc; | |
3334 | ||
3335 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) | |
3336 | return -EOPNOTSUPP; | |
3337 | ||
3338 | if (!value || !size) | |
3339 | return -EACCES; | |
3340 | ||
20ba96ae | 3341 | rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL); |
1da177e4 LT |
3342 | if (rc) |
3343 | return rc; | |
3344 | ||
9287aed2 | 3345 | spin_lock(&isec->lock); |
aa9c2669 | 3346 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3347 | isec->sid = newsid; |
6f3be9f5 | 3348 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3349 | spin_unlock(&isec->lock); |
1da177e4 LT |
3350 | return 0; |
3351 | } | |
3352 | ||
3353 | static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) | |
3354 | { | |
3355 | const int len = sizeof(XATTR_NAME_SELINUX); | |
3356 | if (buffer && len <= buffer_size) | |
3357 | memcpy(buffer, XATTR_NAME_SELINUX, len); | |
3358 | return len; | |
3359 | } | |
3360 | ||
d6335d77 | 3361 | static void selinux_inode_getsecid(struct inode *inode, u32 *secid) |
713a04ae | 3362 | { |
e817c2f3 | 3363 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
713a04ae AD |
3364 | *secid = isec->sid; |
3365 | } | |
3366 | ||
56909eb3 VG |
3367 | static int selinux_inode_copy_up(struct dentry *src, struct cred **new) |
3368 | { | |
3369 | u32 sid; | |
3370 | struct task_security_struct *tsec; | |
3371 | struct cred *new_creds = *new; | |
3372 | ||
3373 | if (new_creds == NULL) { | |
3374 | new_creds = prepare_creds(); | |
3375 | if (!new_creds) | |
3376 | return -ENOMEM; | |
3377 | } | |
3378 | ||
3379 | tsec = new_creds->security; | |
3380 | /* Get label from overlay inode and set it in create_sid */ | |
3381 | selinux_inode_getsecid(d_inode(src), &sid); | |
3382 | tsec->create_sid = sid; | |
3383 | *new = new_creds; | |
3384 | return 0; | |
3385 | } | |
3386 | ||
19472b69 VG |
3387 | static int selinux_inode_copy_up_xattr(const char *name) |
3388 | { | |
3389 | /* The copy_up hook above sets the initial context on an inode, but we | |
3390 | * don't then want to overwrite it by blindly copying all the lower | |
3391 | * xattrs up. Instead, we have to filter out SELinux-related xattrs. | |
3392 | */ | |
3393 | if (strcmp(name, XATTR_NAME_SELINUX) == 0) | |
3394 | return 1; /* Discard */ | |
3395 | /* | |
3396 | * Any other attribute apart from SELINUX is not claimed, supported | |
3397 | * by selinux. | |
3398 | */ | |
3399 | return -EOPNOTSUPP; | |
3400 | } | |
3401 | ||
1da177e4 LT |
3402 | /* file security operations */ |
3403 | ||
788e7dd4 | 3404 | static int selinux_revalidate_file_permission(struct file *file, int mask) |
1da177e4 | 3405 | { |
88e67f3b | 3406 | const struct cred *cred = current_cred(); |
496ad9aa | 3407 | struct inode *inode = file_inode(file); |
1da177e4 | 3408 | |
1da177e4 LT |
3409 | /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ |
3410 | if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) | |
3411 | mask |= MAY_APPEND; | |
3412 | ||
389fb800 PM |
3413 | return file_has_perm(cred, file, |
3414 | file_mask_to_av(inode->i_mode, mask)); | |
1da177e4 LT |
3415 | } |
3416 | ||
788e7dd4 YN |
3417 | static int selinux_file_permission(struct file *file, int mask) |
3418 | { | |
496ad9aa | 3419 | struct inode *inode = file_inode(file); |
20dda18b | 3420 | struct file_security_struct *fsec = file->f_security; |
b197367e | 3421 | struct inode_security_struct *isec; |
20dda18b SS |
3422 | u32 sid = current_sid(); |
3423 | ||
389fb800 | 3424 | if (!mask) |
788e7dd4 YN |
3425 | /* No permission to check. Existence test. */ |
3426 | return 0; | |
788e7dd4 | 3427 | |
b197367e | 3428 | isec = inode_security(inode); |
20dda18b SS |
3429 | if (sid == fsec->sid && fsec->isid == isec->sid && |
3430 | fsec->pseqno == avc_policy_seqno()) | |
83d49856 | 3431 | /* No change since file_open check. */ |
20dda18b SS |
3432 | return 0; |
3433 | ||
788e7dd4 YN |
3434 | return selinux_revalidate_file_permission(file, mask); |
3435 | } | |
3436 | ||
1da177e4 LT |
3437 | static int selinux_file_alloc_security(struct file *file) |
3438 | { | |
3439 | return file_alloc_security(file); | |
3440 | } | |
3441 | ||
3442 | static void selinux_file_free_security(struct file *file) | |
3443 | { | |
3444 | file_free_security(file); | |
3445 | } | |
3446 | ||
fa1aa143 JVS |
3447 | /* |
3448 | * Check whether a task has the ioctl permission and cmd | |
3449 | * operation to an inode. | |
3450 | */ | |
1d2a168a | 3451 | static int ioctl_has_perm(const struct cred *cred, struct file *file, |
fa1aa143 JVS |
3452 | u32 requested, u16 cmd) |
3453 | { | |
3454 | struct common_audit_data ad; | |
3455 | struct file_security_struct *fsec = file->f_security; | |
3456 | struct inode *inode = file_inode(file); | |
20cdef8d | 3457 | struct inode_security_struct *isec; |
fa1aa143 JVS |
3458 | struct lsm_ioctlop_audit ioctl; |
3459 | u32 ssid = cred_sid(cred); | |
3460 | int rc; | |
3461 | u8 driver = cmd >> 8; | |
3462 | u8 xperm = cmd & 0xff; | |
3463 | ||
3464 | ad.type = LSM_AUDIT_DATA_IOCTL_OP; | |
3465 | ad.u.op = &ioctl; | |
3466 | ad.u.op->cmd = cmd; | |
3467 | ad.u.op->path = file->f_path; | |
3468 | ||
3469 | if (ssid != fsec->sid) { | |
3470 | rc = avc_has_perm(ssid, fsec->sid, | |
3471 | SECCLASS_FD, | |
3472 | FD__USE, | |
3473 | &ad); | |
3474 | if (rc) | |
3475 | goto out; | |
3476 | } | |
3477 | ||
3478 | if (unlikely(IS_PRIVATE(inode))) | |
3479 | return 0; | |
3480 | ||
20cdef8d | 3481 | isec = inode_security(inode); |
fa1aa143 JVS |
3482 | rc = avc_has_extended_perms(ssid, isec->sid, isec->sclass, |
3483 | requested, driver, xperm, &ad); | |
3484 | out: | |
3485 | return rc; | |
3486 | } | |
3487 | ||
1da177e4 LT |
3488 | static int selinux_file_ioctl(struct file *file, unsigned int cmd, |
3489 | unsigned long arg) | |
3490 | { | |
88e67f3b | 3491 | const struct cred *cred = current_cred(); |
0b24dcb7 | 3492 | int error = 0; |
1da177e4 | 3493 | |
0b24dcb7 EP |
3494 | switch (cmd) { |
3495 | case FIONREAD: | |
3496 | /* fall through */ | |
3497 | case FIBMAP: | |
3498 | /* fall through */ | |
3499 | case FIGETBSZ: | |
3500 | /* fall through */ | |
2f99c369 | 3501 | case FS_IOC_GETFLAGS: |
0b24dcb7 | 3502 | /* fall through */ |
2f99c369 | 3503 | case FS_IOC_GETVERSION: |
0b24dcb7 EP |
3504 | error = file_has_perm(cred, file, FILE__GETATTR); |
3505 | break; | |
1da177e4 | 3506 | |
2f99c369 | 3507 | case FS_IOC_SETFLAGS: |
0b24dcb7 | 3508 | /* fall through */ |
2f99c369 | 3509 | case FS_IOC_SETVERSION: |
0b24dcb7 EP |
3510 | error = file_has_perm(cred, file, FILE__SETATTR); |
3511 | break; | |
3512 | ||
3513 | /* sys_ioctl() checks */ | |
3514 | case FIONBIO: | |
3515 | /* fall through */ | |
3516 | case FIOASYNC: | |
3517 | error = file_has_perm(cred, file, 0); | |
3518 | break; | |
1da177e4 | 3519 | |
0b24dcb7 EP |
3520 | case KDSKBENT: |
3521 | case KDSKBSENT: | |
6a9de491 | 3522 | error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, |
8e4ff6f2 | 3523 | SECURITY_CAP_AUDIT, true); |
0b24dcb7 EP |
3524 | break; |
3525 | ||
3526 | /* default case assumes that the command will go | |
3527 | * to the file's ioctl() function. | |
3528 | */ | |
3529 | default: | |
fa1aa143 | 3530 | error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); |
0b24dcb7 EP |
3531 | } |
3532 | return error; | |
1da177e4 LT |
3533 | } |
3534 | ||
fcaaade1 SS |
3535 | static int default_noexec; |
3536 | ||
1da177e4 LT |
3537 | static int file_map_prot_check(struct file *file, unsigned long prot, int shared) |
3538 | { | |
88e67f3b | 3539 | const struct cred *cred = current_cred(); |
be0554c9 | 3540 | u32 sid = cred_sid(cred); |
d84f4f99 | 3541 | int rc = 0; |
88e67f3b | 3542 | |
fcaaade1 | 3543 | if (default_noexec && |
892e8cac SS |
3544 | (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) || |
3545 | (!shared && (prot & PROT_WRITE)))) { | |
1da177e4 LT |
3546 | /* |
3547 | * We are making executable an anonymous mapping or a | |
3548 | * private file mapping that will also be writable. | |
3549 | * This has an additional check. | |
3550 | */ | |
be0554c9 SS |
3551 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3552 | PROCESS__EXECMEM, NULL); | |
1da177e4 | 3553 | if (rc) |
d84f4f99 | 3554 | goto error; |
1da177e4 | 3555 | } |
1da177e4 LT |
3556 | |
3557 | if (file) { | |
3558 | /* read access is always possible with a mapping */ | |
3559 | u32 av = FILE__READ; | |
3560 | ||
3561 | /* write access only matters if the mapping is shared */ | |
3562 | if (shared && (prot & PROT_WRITE)) | |
3563 | av |= FILE__WRITE; | |
3564 | ||
3565 | if (prot & PROT_EXEC) | |
3566 | av |= FILE__EXECUTE; | |
3567 | ||
88e67f3b | 3568 | return file_has_perm(cred, file, av); |
1da177e4 | 3569 | } |
d84f4f99 DH |
3570 | |
3571 | error: | |
3572 | return rc; | |
1da177e4 LT |
3573 | } |
3574 | ||
e5467859 | 3575 | static int selinux_mmap_addr(unsigned long addr) |
1da177e4 | 3576 | { |
b1d9e6b0 | 3577 | int rc = 0; |
1da177e4 | 3578 | |
a2551df7 | 3579 | if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { |
98883bfd | 3580 | u32 sid = current_sid(); |
ed032189 EP |
3581 | rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, |
3582 | MEMPROTECT__MMAP_ZERO, NULL); | |
84336d1a EP |
3583 | } |
3584 | ||
98883bfd | 3585 | return rc; |
e5467859 | 3586 | } |
1da177e4 | 3587 | |
e5467859 AV |
3588 | static int selinux_mmap_file(struct file *file, unsigned long reqprot, |
3589 | unsigned long prot, unsigned long flags) | |
3590 | { | |
3ba4bf5f SS |
3591 | struct common_audit_data ad; |
3592 | int rc; | |
3593 | ||
3594 | if (file) { | |
3595 | ad.type = LSM_AUDIT_DATA_FILE; | |
3596 | ad.u.file = file; | |
3597 | rc = inode_has_perm(current_cred(), file_inode(file), | |
3598 | FILE__MAP, &ad); | |
3599 | if (rc) | |
3600 | return rc; | |
3601 | } | |
3602 | ||
1da177e4 LT |
3603 | if (selinux_checkreqprot) |
3604 | prot = reqprot; | |
3605 | ||
3606 | return file_map_prot_check(file, prot, | |
3607 | (flags & MAP_TYPE) == MAP_SHARED); | |
3608 | } | |
3609 | ||
3610 | static int selinux_file_mprotect(struct vm_area_struct *vma, | |
3611 | unsigned long reqprot, | |
3612 | unsigned long prot) | |
3613 | { | |
88e67f3b | 3614 | const struct cred *cred = current_cred(); |
be0554c9 | 3615 | u32 sid = cred_sid(cred); |
1da177e4 LT |
3616 | |
3617 | if (selinux_checkreqprot) | |
3618 | prot = reqprot; | |
3619 | ||
fcaaade1 SS |
3620 | if (default_noexec && |
3621 | (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { | |
d541bbee | 3622 | int rc = 0; |
db4c9641 SS |
3623 | if (vma->vm_start >= vma->vm_mm->start_brk && |
3624 | vma->vm_end <= vma->vm_mm->brk) { | |
be0554c9 SS |
3625 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3626 | PROCESS__EXECHEAP, NULL); | |
db4c9641 | 3627 | } else if (!vma->vm_file && |
c2316dbf SS |
3628 | ((vma->vm_start <= vma->vm_mm->start_stack && |
3629 | vma->vm_end >= vma->vm_mm->start_stack) || | |
d17af505 | 3630 | vma_is_stack_for_current(vma))) { |
be0554c9 SS |
3631 | rc = avc_has_perm(sid, sid, SECCLASS_PROCESS, |
3632 | PROCESS__EXECSTACK, NULL); | |
db4c9641 SS |
3633 | } else if (vma->vm_file && vma->anon_vma) { |
3634 | /* | |
3635 | * We are making executable a file mapping that has | |
3636 | * had some COW done. Since pages might have been | |
3637 | * written, check ability to execute the possibly | |
3638 | * modified content. This typically should only | |
3639 | * occur for text relocations. | |
3640 | */ | |
d84f4f99 | 3641 | rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); |
db4c9641 | 3642 | } |