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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> |
d452930f RH |
70 | #include <linux/sctp.h> |
71 | #include <net/sctp/structs.h> | |
1da177e4 LT |
72 | #include <linux/quota.h> |
73 | #include <linux/un.h> /* for Unix socket types */ | |
74 | #include <net/af_unix.h> /* for Unix socket types */ | |
75 | #include <linux/parser.h> | |
76 | #include <linux/nfs_mount.h> | |
77 | #include <net/ipv6.h> | |
78 | #include <linux/hugetlb.h> | |
79 | #include <linux/personality.h> | |
1da177e4 | 80 | #include <linux/audit.h> |
6931dfc9 | 81 | #include <linux/string.h> |
877ce7c1 | 82 | #include <linux/selinux.h> |
23970741 | 83 | #include <linux/mutex.h> |
f06febc9 | 84 | #include <linux/posix-timers.h> |
00234592 | 85 | #include <linux/syslog.h> |
3486740a | 86 | #include <linux/user_namespace.h> |
44fc7ea0 | 87 | #include <linux/export.h> |
40401530 AV |
88 | #include <linux/msg.h> |
89 | #include <linux/shm.h> | |
ec27c356 | 90 | #include <linux/bpf.h> |
e262e32d | 91 | #include <uapi/linux/mount.h> |
1da177e4 LT |
92 | |
93 | #include "avc.h" | |
94 | #include "objsec.h" | |
95 | #include "netif.h" | |
224dfbd8 | 96 | #include "netnode.h" |
3e112172 | 97 | #include "netport.h" |
409dcf31 | 98 | #include "ibpkey.h" |
d28d1e08 | 99 | #include "xfrm.h" |
c60475bf | 100 | #include "netlabel.h" |
9d57a7f9 | 101 | #include "audit.h" |
7b98a585 | 102 | #include "avc_ss.h" |
1da177e4 | 103 | |
aa8e712c SS |
104 | struct selinux_state selinux_state; |
105 | ||
d621d35e | 106 | /* SECMARK reference count */ |
56a4ca99 | 107 | static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); |
d621d35e | 108 | |
1da177e4 | 109 | #ifdef CONFIG_SECURITY_SELINUX_DEVELOP |
aa8e712c | 110 | static int selinux_enforcing_boot; |
1da177e4 LT |
111 | |
112 | static int __init enforcing_setup(char *str) | |
113 | { | |
f5269710 | 114 | unsigned long enforcing; |
29707b20 | 115 | if (!kstrtoul(str, 0, &enforcing)) |
aa8e712c | 116 | selinux_enforcing_boot = enforcing ? 1 : 0; |
1da177e4 LT |
117 | return 1; |
118 | } | |
119 | __setup("enforcing=", enforcing_setup); | |
aa8e712c SS |
120 | #else |
121 | #define selinux_enforcing_boot 1 | |
1da177e4 LT |
122 | #endif |
123 | ||
124 | #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM | |
125 | int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; | |
126 | ||
127 | static int __init selinux_enabled_setup(char *str) | |
128 | { | |
f5269710 | 129 | unsigned long enabled; |
29707b20 | 130 | if (!kstrtoul(str, 0, &enabled)) |
f5269710 | 131 | selinux_enabled = enabled ? 1 : 0; |
1da177e4 LT |
132 | return 1; |
133 | } | |
134 | __setup("selinux=", selinux_enabled_setup); | |
30d55280 SS |
135 | #else |
136 | int selinux_enabled = 1; | |
1da177e4 LT |
137 | #endif |
138 | ||
aa8e712c SS |
139 | static unsigned int selinux_checkreqprot_boot = |
140 | CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE; | |
141 | ||
142 | static int __init checkreqprot_setup(char *str) | |
143 | { | |
144 | unsigned long checkreqprot; | |
145 | ||
146 | if (!kstrtoul(str, 0, &checkreqprot)) | |
147 | selinux_checkreqprot_boot = checkreqprot ? 1 : 0; | |
148 | return 1; | |
149 | } | |
150 | __setup("checkreqprot=", checkreqprot_setup); | |
151 | ||
e18b890b | 152 | static struct kmem_cache *sel_inode_cache; |
63205654 | 153 | static struct kmem_cache *file_security_cache; |
7cae7e26 | 154 | |
d621d35e PM |
155 | /** |
156 | * selinux_secmark_enabled - Check to see if SECMARK is currently enabled | |
157 | * | |
158 | * Description: | |
159 | * This function checks the SECMARK reference counter to see if any SECMARK | |
160 | * targets are currently configured, if the reference counter is greater than | |
161 | * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is | |
2be4d74f CP |
162 | * enabled, false (0) if SECMARK is disabled. If the always_check_network |
163 | * policy capability is enabled, SECMARK is always considered enabled. | |
d621d35e PM |
164 | * |
165 | */ | |
166 | static int selinux_secmark_enabled(void) | |
167 | { | |
aa8e712c SS |
168 | return (selinux_policycap_alwaysnetwork() || |
169 | atomic_read(&selinux_secmark_refcount)); | |
2be4d74f CP |
170 | } |
171 | ||
172 | /** | |
173 | * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled | |
174 | * | |
175 | * Description: | |
176 | * This function checks if NetLabel or labeled IPSEC is enabled. Returns true | |
177 | * (1) if any are enabled or false (0) if neither are enabled. If the | |
178 | * always_check_network policy capability is enabled, peer labeling | |
179 | * is always considered enabled. | |
180 | * | |
181 | */ | |
182 | static int selinux_peerlbl_enabled(void) | |
183 | { | |
aa8e712c SS |
184 | return (selinux_policycap_alwaysnetwork() || |
185 | netlbl_enabled() || selinux_xfrm_enabled()); | |
d621d35e PM |
186 | } |
187 | ||
615e51fd PM |
188 | static int selinux_netcache_avc_callback(u32 event) |
189 | { | |
190 | if (event == AVC_CALLBACK_RESET) { | |
191 | sel_netif_flush(); | |
192 | sel_netnode_flush(); | |
193 | sel_netport_flush(); | |
194 | synchronize_net(); | |
195 | } | |
196 | return 0; | |
197 | } | |
198 | ||
8f408ab6 DJ |
199 | static int selinux_lsm_notifier_avc_callback(u32 event) |
200 | { | |
409dcf31 DJ |
201 | if (event == AVC_CALLBACK_RESET) { |
202 | sel_ib_pkey_flush(); | |
8f408ab6 | 203 | call_lsm_notifier(LSM_POLICY_CHANGE, NULL); |
409dcf31 | 204 | } |
8f408ab6 DJ |
205 | |
206 | return 0; | |
207 | } | |
208 | ||
d84f4f99 DH |
209 | /* |
210 | * initialise the security for the init task | |
211 | */ | |
212 | static void cred_init_security(void) | |
1da177e4 | 213 | { |
3b11a1de | 214 | struct cred *cred = (struct cred *) current->real_cred; |
1da177e4 LT |
215 | struct task_security_struct *tsec; |
216 | ||
89d155ef | 217 | tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); |
1da177e4 | 218 | if (!tsec) |
d84f4f99 | 219 | panic("SELinux: Failed to initialize initial task.\n"); |
1da177e4 | 220 | |
d84f4f99 | 221 | tsec->osid = tsec->sid = SECINITSID_KERNEL; |
f1752eec | 222 | cred->security = tsec; |
1da177e4 LT |
223 | } |
224 | ||
88e67f3b DH |
225 | /* |
226 | * get the security ID of a set of credentials | |
227 | */ | |
228 | static inline u32 cred_sid(const struct cred *cred) | |
229 | { | |
230 | const struct task_security_struct *tsec; | |
231 | ||
232 | tsec = cred->security; | |
233 | return tsec->sid; | |
234 | } | |
235 | ||
275bb41e | 236 | /* |
3b11a1de | 237 | * get the objective security ID of a task |
275bb41e DH |
238 | */ |
239 | static inline u32 task_sid(const struct task_struct *task) | |
240 | { | |
275bb41e DH |
241 | u32 sid; |
242 | ||
243 | rcu_read_lock(); | |
88e67f3b | 244 | sid = cred_sid(__task_cred(task)); |
275bb41e DH |
245 | rcu_read_unlock(); |
246 | return sid; | |
247 | } | |
248 | ||
88e67f3b DH |
249 | /* Allocate and free functions for each kind of security blob. */ |
250 | ||
1da177e4 LT |
251 | static int inode_alloc_security(struct inode *inode) |
252 | { | |
1da177e4 | 253 | struct inode_security_struct *isec; |
275bb41e | 254 | u32 sid = current_sid(); |
1da177e4 | 255 | |
a02fe132 | 256 | isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); |
1da177e4 LT |
257 | if (!isec) |
258 | return -ENOMEM; | |
259 | ||
9287aed2 | 260 | spin_lock_init(&isec->lock); |
1da177e4 | 261 | INIT_LIST_HEAD(&isec->list); |
1da177e4 LT |
262 | isec->inode = inode; |
263 | isec->sid = SECINITSID_UNLABELED; | |
264 | isec->sclass = SECCLASS_FILE; | |
275bb41e | 265 | isec->task_sid = sid; |
42059112 | 266 | isec->initialized = LABEL_INVALID; |
1da177e4 LT |
267 | inode->i_security = isec; |
268 | ||
269 | return 0; | |
270 | } | |
271 | ||
5d226df4 AG |
272 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); |
273 | ||
274 | /* | |
275 | * Try reloading inode security labels that have been marked as invalid. The | |
276 | * @may_sleep parameter indicates when sleeping and thus reloading labels is | |
42059112 | 277 | * allowed; when set to false, returns -ECHILD when the label is |
e9193288 | 278 | * invalid. The @dentry parameter should be set to a dentry of the inode. |
5d226df4 AG |
279 | */ |
280 | static int __inode_security_revalidate(struct inode *inode, | |
e9193288 | 281 | struct dentry *dentry, |
5d226df4 AG |
282 | bool may_sleep) |
283 | { | |
284 | struct inode_security_struct *isec = inode->i_security; | |
285 | ||
286 | might_sleep_if(may_sleep); | |
287 | ||
aa8e712c SS |
288 | if (selinux_state.initialized && |
289 | isec->initialized != LABEL_INITIALIZED) { | |
5d226df4 AG |
290 | if (!may_sleep) |
291 | return -ECHILD; | |
292 | ||
293 | /* | |
294 | * Try reloading the inode security label. This will fail if | |
295 | * @opt_dentry is NULL and no dentry for this inode can be | |
296 | * found; in that case, continue using the old label. | |
297 | */ | |
e9193288 | 298 | inode_doinit_with_dentry(inode, dentry); |
5d226df4 AG |
299 | } |
300 | return 0; | |
301 | } | |
302 | ||
5d226df4 AG |
303 | static struct inode_security_struct *inode_security_novalidate(struct inode *inode) |
304 | { | |
305 | return inode->i_security; | |
306 | } | |
307 | ||
308 | static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu) | |
309 | { | |
310 | int error; | |
311 | ||
312 | error = __inode_security_revalidate(inode, NULL, !rcu); | |
313 | if (error) | |
314 | return ERR_PTR(error); | |
315 | return inode->i_security; | |
316 | } | |
317 | ||
83da53c5 AG |
318 | /* |
319 | * Get the security label of an inode. | |
320 | */ | |
321 | static struct inode_security_struct *inode_security(struct inode *inode) | |
322 | { | |
5d226df4 | 323 | __inode_security_revalidate(inode, NULL, true); |
83da53c5 AG |
324 | return inode->i_security; |
325 | } | |
326 | ||
2c97165b PM |
327 | static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry) |
328 | { | |
329 | struct inode *inode = d_backing_inode(dentry); | |
330 | ||
331 | return inode->i_security; | |
332 | } | |
333 | ||
83da53c5 AG |
334 | /* |
335 | * Get the security label of a dentry's backing inode. | |
336 | */ | |
337 | static struct inode_security_struct *backing_inode_security(struct dentry *dentry) | |
338 | { | |
339 | struct inode *inode = d_backing_inode(dentry); | |
340 | ||
5d226df4 | 341 | __inode_security_revalidate(inode, dentry, true); |
83da53c5 AG |
342 | return inode->i_security; |
343 | } | |
344 | ||
3dc91d43 SR |
345 | static void inode_free_rcu(struct rcu_head *head) |
346 | { | |
347 | struct inode_security_struct *isec; | |
348 | ||
349 | isec = container_of(head, struct inode_security_struct, rcu); | |
350 | kmem_cache_free(sel_inode_cache, isec); | |
351 | } | |
352 | ||
1da177e4 LT |
353 | static void inode_free_security(struct inode *inode) |
354 | { | |
355 | struct inode_security_struct *isec = inode->i_security; | |
356 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; | |
357 | ||
9629d04a WL |
358 | /* |
359 | * As not all inode security structures are in a list, we check for | |
360 | * empty list outside of the lock to make sure that we won't waste | |
361 | * time taking a lock doing nothing. | |
362 | * | |
363 | * The list_del_init() function can be safely called more than once. | |
364 | * It should not be possible for this function to be called with | |
365 | * concurrent list_add(), but for better safety against future changes | |
366 | * in the code, we use list_empty_careful() here. | |
367 | */ | |
368 | if (!list_empty_careful(&isec->list)) { | |
369 | spin_lock(&sbsec->isec_lock); | |
1da177e4 | 370 | list_del_init(&isec->list); |
9629d04a WL |
371 | spin_unlock(&sbsec->isec_lock); |
372 | } | |
1da177e4 | 373 | |
3dc91d43 SR |
374 | /* |
375 | * The inode may still be referenced in a path walk and | |
376 | * a call to selinux_inode_permission() can be made | |
377 | * after inode_free_security() is called. Ideally, the VFS | |
378 | * wouldn't do this, but fixing that is a much harder | |
379 | * job. For now, simply free the i_security via RCU, and | |
380 | * leave the current inode->i_security pointer intact. | |
381 | * The inode will be freed after the RCU grace period too. | |
382 | */ | |
383 | call_rcu(&isec->rcu, inode_free_rcu); | |
1da177e4 LT |
384 | } |
385 | ||
386 | static int file_alloc_security(struct file *file) | |
387 | { | |
1da177e4 | 388 | struct file_security_struct *fsec; |
275bb41e | 389 | u32 sid = current_sid(); |
1da177e4 | 390 | |
63205654 | 391 | fsec = kmem_cache_zalloc(file_security_cache, GFP_KERNEL); |
1da177e4 LT |
392 | if (!fsec) |
393 | return -ENOMEM; | |
394 | ||
275bb41e DH |
395 | fsec->sid = sid; |
396 | fsec->fown_sid = sid; | |
1da177e4 LT |
397 | file->f_security = fsec; |
398 | ||
399 | return 0; | |
400 | } | |
401 | ||
402 | static void file_free_security(struct file *file) | |
403 | { | |
404 | struct file_security_struct *fsec = file->f_security; | |
1da177e4 | 405 | file->f_security = NULL; |
63205654 | 406 | kmem_cache_free(file_security_cache, fsec); |
1da177e4 LT |
407 | } |
408 | ||
409 | static int superblock_alloc_security(struct super_block *sb) | |
410 | { | |
411 | struct superblock_security_struct *sbsec; | |
412 | ||
89d155ef | 413 | sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); |
1da177e4 LT |
414 | if (!sbsec) |
415 | return -ENOMEM; | |
416 | ||
bc7e982b | 417 | mutex_init(&sbsec->lock); |
1da177e4 LT |
418 | INIT_LIST_HEAD(&sbsec->isec_head); |
419 | spin_lock_init(&sbsec->isec_lock); | |
1da177e4 LT |
420 | sbsec->sb = sb; |
421 | sbsec->sid = SECINITSID_UNLABELED; | |
422 | sbsec->def_sid = SECINITSID_FILE; | |
c312feb2 | 423 | sbsec->mntpoint_sid = SECINITSID_UNLABELED; |
1da177e4 LT |
424 | sb->s_security = sbsec; |
425 | ||
426 | return 0; | |
427 | } | |
428 | ||
429 | static void superblock_free_security(struct super_block *sb) | |
430 | { | |
431 | struct superblock_security_struct *sbsec = sb->s_security; | |
1da177e4 LT |
432 | sb->s_security = NULL; |
433 | kfree(sbsec); | |
434 | } | |
435 | ||
bd323655 AV |
436 | struct selinux_mnt_opts { |
437 | const char *fscontext, *context, *rootcontext, *defcontext; | |
438 | }; | |
439 | ||
204cc0cc AV |
440 | static void selinux_free_mnt_opts(void *mnt_opts) |
441 | { | |
bd323655 AV |
442 | struct selinux_mnt_opts *opts = mnt_opts; |
443 | kfree(opts->fscontext); | |
444 | kfree(opts->context); | |
445 | kfree(opts->rootcontext); | |
446 | kfree(opts->defcontext); | |
204cc0cc AV |
447 | kfree(opts); |
448 | } | |
449 | ||
1da177e4 LT |
450 | static inline int inode_doinit(struct inode *inode) |
451 | { | |
452 | return inode_doinit_with_dentry(inode, NULL); | |
453 | } | |
454 | ||
455 | enum { | |
31e87930 | 456 | Opt_error = -1, |
1da177e4 LT |
457 | Opt_context = 1, |
458 | Opt_fscontext = 2, | |
c9180a57 EP |
459 | Opt_defcontext = 3, |
460 | Opt_rootcontext = 4, | |
da3d76ab | 461 | Opt_seclabel = 5, |
1da177e4 LT |
462 | }; |
463 | ||
da3d76ab | 464 | #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg} |
169d68ef AV |
465 | static struct { |
466 | const char *name; | |
467 | int len; | |
468 | int opt; | |
469 | bool has_arg; | |
470 | } tokens[] = { | |
da3d76ab AV |
471 | A(context, true), |
472 | A(fscontext, true), | |
473 | A(defcontext, true), | |
474 | A(rootcontext, true), | |
475 | A(seclabel, false), | |
1da177e4 | 476 | }; |
169d68ef AV |
477 | #undef A |
478 | ||
479 | static int match_opt_prefix(char *s, int l, char **arg) | |
480 | { | |
481 | int i; | |
482 | ||
483 | for (i = 0; i < ARRAY_SIZE(tokens); i++) { | |
484 | size_t len = tokens[i].len; | |
485 | if (len > l || memcmp(s, tokens[i].name, len)) | |
486 | continue; | |
487 | if (tokens[i].has_arg) { | |
488 | if (len == l || s[len] != '=') | |
489 | continue; | |
490 | *arg = s + len + 1; | |
491 | } else if (len != l) | |
492 | continue; | |
493 | return tokens[i].opt; | |
494 | } | |
495 | return Opt_error; | |
496 | } | |
1da177e4 LT |
497 | |
498 | #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" | |
499 | ||
c312feb2 EP |
500 | static int may_context_mount_sb_relabel(u32 sid, |
501 | struct superblock_security_struct *sbsec, | |
275bb41e | 502 | const struct cred *cred) |
c312feb2 | 503 | { |
275bb41e | 504 | const struct task_security_struct *tsec = cred->security; |
c312feb2 EP |
505 | int rc; |
506 | ||
6b6bc620 SS |
507 | rc = avc_has_perm(&selinux_state, |
508 | tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
c312feb2 EP |
509 | FILESYSTEM__RELABELFROM, NULL); |
510 | if (rc) | |
511 | return rc; | |
512 | ||
6b6bc620 SS |
513 | rc = avc_has_perm(&selinux_state, |
514 | tsec->sid, sid, SECCLASS_FILESYSTEM, | |
c312feb2 EP |
515 | FILESYSTEM__RELABELTO, NULL); |
516 | return rc; | |
517 | } | |
518 | ||
0808925e EP |
519 | static int may_context_mount_inode_relabel(u32 sid, |
520 | struct superblock_security_struct *sbsec, | |
275bb41e | 521 | const struct cred *cred) |
0808925e | 522 | { |
275bb41e | 523 | const struct task_security_struct *tsec = cred->security; |
0808925e | 524 | int rc; |
6b6bc620 SS |
525 | rc = avc_has_perm(&selinux_state, |
526 | tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
0808925e EP |
527 | FILESYSTEM__RELABELFROM, NULL); |
528 | if (rc) | |
529 | return rc; | |
530 | ||
6b6bc620 SS |
531 | rc = avc_has_perm(&selinux_state, |
532 | sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
0808925e EP |
533 | FILESYSTEM__ASSOCIATE, NULL); |
534 | return rc; | |
535 | } | |
536 | ||
a83d6dda | 537 | static int selinux_is_genfs_special_handling(struct super_block *sb) |
b43e725d | 538 | { |
a83d6dda OM |
539 | /* Special handling. Genfs but also in-core setxattr handler */ |
540 | return !strcmp(sb->s_type->name, "sysfs") || | |
d5f3a5f6 MS |
541 | !strcmp(sb->s_type->name, "pstore") || |
542 | !strcmp(sb->s_type->name, "debugfs") || | |
a2c7c6fb | 543 | !strcmp(sb->s_type->name, "tracefs") || |
2651225b | 544 | !strcmp(sb->s_type->name, "rootfs") || |
aa8e712c | 545 | (selinux_policycap_cgroupseclabel() && |
2651225b SS |
546 | (!strcmp(sb->s_type->name, "cgroup") || |
547 | !strcmp(sb->s_type->name, "cgroup2"))); | |
b43e725d EP |
548 | } |
549 | ||
a83d6dda OM |
550 | static int selinux_is_sblabel_mnt(struct super_block *sb) |
551 | { | |
552 | struct superblock_security_struct *sbsec = sb->s_security; | |
553 | ||
554 | /* | |
555 | * IMPORTANT: Double-check logic in this function when adding a new | |
556 | * SECURITY_FS_USE_* definition! | |
557 | */ | |
558 | BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7); | |
559 | ||
560 | switch (sbsec->behavior) { | |
561 | case SECURITY_FS_USE_XATTR: | |
562 | case SECURITY_FS_USE_TRANS: | |
563 | case SECURITY_FS_USE_TASK: | |
564 | case SECURITY_FS_USE_NATIVE: | |
565 | return 1; | |
566 | ||
567 | case SECURITY_FS_USE_GENFS: | |
568 | return selinux_is_genfs_special_handling(sb); | |
569 | ||
570 | /* Never allow relabeling on context mounts */ | |
571 | case SECURITY_FS_USE_MNTPOINT: | |
572 | case SECURITY_FS_USE_NONE: | |
573 | default: | |
574 | return 0; | |
575 | } | |
576 | } | |
577 | ||
c9180a57 | 578 | static int sb_finish_set_opts(struct super_block *sb) |
1da177e4 | 579 | { |
1da177e4 | 580 | struct superblock_security_struct *sbsec = sb->s_security; |
c9180a57 | 581 | struct dentry *root = sb->s_root; |
c6f493d6 | 582 | struct inode *root_inode = d_backing_inode(root); |
c9180a57 | 583 | int rc = 0; |
1da177e4 | 584 | |
c9180a57 EP |
585 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { |
586 | /* Make sure that the xattr handler exists and that no | |
587 | error other than -ENODATA is returned by getxattr on | |
588 | the root directory. -ENODATA is ok, as this may be | |
589 | the first boot of the SELinux kernel before we have | |
590 | assigned xattr values to the filesystem. */ | |
5d6c3191 | 591 | if (!(root_inode->i_opflags & IOP_XATTR)) { |
c103a91e | 592 | pr_warn("SELinux: (dev %s, type %s) has no " |
29b1deb2 | 593 | "xattr support\n", sb->s_id, sb->s_type->name); |
c9180a57 EP |
594 | rc = -EOPNOTSUPP; |
595 | goto out; | |
596 | } | |
5d6c3191 AG |
597 | |
598 | rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0); | |
c9180a57 EP |
599 | if (rc < 0 && rc != -ENODATA) { |
600 | if (rc == -EOPNOTSUPP) | |
c103a91e | 601 | pr_warn("SELinux: (dev %s, type " |
29b1deb2 LT |
602 | "%s) has no security xattr handler\n", |
603 | sb->s_id, sb->s_type->name); | |
c9180a57 | 604 | else |
c103a91e | 605 | pr_warn("SELinux: (dev %s, type " |
29b1deb2 LT |
606 | "%s) getxattr errno %d\n", sb->s_id, |
607 | sb->s_type->name, -rc); | |
c9180a57 EP |
608 | goto out; |
609 | } | |
610 | } | |
1da177e4 | 611 | |
eadcabc6 | 612 | sbsec->flags |= SE_SBINITIALIZED; |
0b4d3452 SM |
613 | |
614 | /* | |
615 | * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply | |
616 | * leave the flag untouched because sb_clone_mnt_opts might be handing | |
617 | * us a superblock that needs the flag to be cleared. | |
618 | */ | |
b43e725d | 619 | if (selinux_is_sblabel_mnt(sb)) |
12f348b9 | 620 | sbsec->flags |= SBLABEL_MNT; |
0b4d3452 SM |
621 | else |
622 | sbsec->flags &= ~SBLABEL_MNT; | |
ddd29ec6 | 623 | |
c9180a57 EP |
624 | /* Initialize the root inode. */ |
625 | rc = inode_doinit_with_dentry(root_inode, root); | |
1da177e4 | 626 | |
c9180a57 EP |
627 | /* Initialize any other inodes associated with the superblock, e.g. |
628 | inodes created prior to initial policy load or inodes created | |
629 | during get_sb by a pseudo filesystem that directly | |
630 | populates itself. */ | |
631 | spin_lock(&sbsec->isec_lock); | |
8d64124a | 632 | while (!list_empty(&sbsec->isec_head)) { |
c9180a57 | 633 | struct inode_security_struct *isec = |
8d64124a | 634 | list_first_entry(&sbsec->isec_head, |
c9180a57 EP |
635 | struct inode_security_struct, list); |
636 | struct inode *inode = isec->inode; | |
923190d3 | 637 | list_del_init(&isec->list); |
c9180a57 EP |
638 | spin_unlock(&sbsec->isec_lock); |
639 | inode = igrab(inode); | |
640 | if (inode) { | |
641 | if (!IS_PRIVATE(inode)) | |
642 | inode_doinit(inode); | |
643 | iput(inode); | |
644 | } | |
645 | spin_lock(&sbsec->isec_lock); | |
c9180a57 EP |
646 | } |
647 | spin_unlock(&sbsec->isec_lock); | |
648 | out: | |
649 | return rc; | |
650 | } | |
1da177e4 | 651 | |
c9180a57 EP |
652 | static int bad_option(struct superblock_security_struct *sbsec, char flag, |
653 | u32 old_sid, u32 new_sid) | |
654 | { | |
0d90a7ec DQ |
655 | char mnt_flags = sbsec->flags & SE_MNTMASK; |
656 | ||
c9180a57 | 657 | /* check if the old mount command had the same options */ |
0d90a7ec | 658 | if (sbsec->flags & SE_SBINITIALIZED) |
c9180a57 EP |
659 | if (!(sbsec->flags & flag) || |
660 | (old_sid != new_sid)) | |
661 | return 1; | |
662 | ||
663 | /* check if we were passed the same options twice, | |
664 | * aka someone passed context=a,context=b | |
665 | */ | |
0d90a7ec DQ |
666 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
667 | if (mnt_flags & flag) | |
c9180a57 EP |
668 | return 1; |
669 | return 0; | |
670 | } | |
e0007529 | 671 | |
bd323655 AV |
672 | static int parse_sid(struct super_block *sb, const char *s, u32 *sid) |
673 | { | |
674 | int rc = security_context_str_to_sid(&selinux_state, s, | |
675 | sid, GFP_KERNEL); | |
676 | if (rc) | |
677 | pr_warn("SELinux: security_context_str_to_sid" | |
678 | "(%s) failed for (dev %s, type %s) errno=%d\n", | |
679 | s, sb->s_id, sb->s_type->name, rc); | |
680 | return rc; | |
681 | } | |
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, |
204cc0cc | 688 | void *mnt_opts, |
649f6e77 DQ |
689 | unsigned long kern_flags, |
690 | unsigned long *set_kern_flags) | |
c9180a57 | 691 | { |
275bb41e | 692 | const struct cred *cred = current_cred(); |
c9180a57 | 693 | struct superblock_security_struct *sbsec = sb->s_security; |
83da53c5 | 694 | struct dentry *root = sbsec->sb->s_root; |
bd323655 | 695 | struct selinux_mnt_opts *opts = mnt_opts; |
2c97165b | 696 | struct inode_security_struct *root_isec; |
c9180a57 EP |
697 | u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; |
698 | u32 defcontext_sid = 0; | |
bd323655 | 699 | int rc = 0; |
c9180a57 EP |
700 | |
701 | mutex_lock(&sbsec->lock); | |
702 | ||
aa8e712c | 703 | if (!selinux_state.initialized) { |
bd323655 | 704 | if (!opts) { |
c9180a57 EP |
705 | /* Defer initialization until selinux_complete_init, |
706 | after the initial policy is loaded and the security | |
707 | server is ready to handle calls. */ | |
c9180a57 EP |
708 | goto out; |
709 | } | |
710 | rc = -EINVAL; | |
c103a91e | 711 | pr_warn("SELinux: Unable to set superblock options " |
744ba35e | 712 | "before the security server is initialized\n"); |
1da177e4 | 713 | goto out; |
c9180a57 | 714 | } |
649f6e77 DQ |
715 | if (kern_flags && !set_kern_flags) { |
716 | /* Specifying internal flags without providing a place to | |
717 | * place the results is not allowed */ | |
718 | rc = -EINVAL; | |
719 | goto out; | |
720 | } | |
1da177e4 | 721 | |
e0007529 EP |
722 | /* |
723 | * Binary mount data FS will come through this function twice. Once | |
724 | * from an explicit call and once from the generic calls from the vfs. | |
725 | * Since the generic VFS calls will not contain any security mount data | |
726 | * we need to skip the double mount verification. | |
727 | * | |
728 | * This does open a hole in which we will not notice if the first | |
729 | * mount using this sb set explict options and a second mount using | |
730 | * this sb does not set any security options. (The first options | |
731 | * will be used for both mounts) | |
732 | */ | |
0d90a7ec | 733 | if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) |
bd323655 | 734 | && !opts) |
f5269710 | 735 | goto out; |
e0007529 | 736 | |
2c97165b PM |
737 | root_isec = backing_inode_security_novalidate(root); |
738 | ||
c9180a57 EP |
739 | /* |
740 | * parse the mount options, check if they are valid sids. | |
741 | * also check if someone is trying to mount the same sb more | |
742 | * than once with different security options. | |
743 | */ | |
bd323655 AV |
744 | if (opts) { |
745 | if (opts->fscontext) { | |
746 | rc = parse_sid(sb, opts->fscontext, &fscontext_sid); | |
747 | if (rc) | |
748 | goto out; | |
c9180a57 EP |
749 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, |
750 | fscontext_sid)) | |
751 | goto out_double_mount; | |
c9180a57 | 752 | sbsec->flags |= FSCONTEXT_MNT; |
bd323655 AV |
753 | } |
754 | if (opts->context) { | |
755 | rc = parse_sid(sb, opts->context, &context_sid); | |
756 | if (rc) | |
757 | goto out; | |
c9180a57 EP |
758 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, |
759 | context_sid)) | |
760 | goto out_double_mount; | |
c9180a57 | 761 | sbsec->flags |= CONTEXT_MNT; |
bd323655 AV |
762 | } |
763 | if (opts->rootcontext) { | |
764 | rc = parse_sid(sb, opts->rootcontext, &rootcontext_sid); | |
765 | if (rc) | |
766 | goto out; | |
c9180a57 EP |
767 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, |
768 | rootcontext_sid)) | |
769 | goto out_double_mount; | |
c9180a57 | 770 | sbsec->flags |= ROOTCONTEXT_MNT; |
bd323655 AV |
771 | } |
772 | if (opts->defcontext) { | |
773 | rc = parse_sid(sb, opts->defcontext, &defcontext_sid); | |
774 | if (rc) | |
775 | goto out; | |
c9180a57 EP |
776 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, |
777 | defcontext_sid)) | |
778 | goto out_double_mount; | |
c9180a57 | 779 | sbsec->flags |= DEFCONTEXT_MNT; |
1da177e4 | 780 | } |
c9180a57 EP |
781 | } |
782 | ||
0d90a7ec | 783 | if (sbsec->flags & SE_SBINITIALIZED) { |
c9180a57 | 784 | /* previously mounted with options, but not on this attempt? */ |
bd323655 | 785 | if ((sbsec->flags & SE_MNTMASK) && !opts) |
c9180a57 EP |
786 | goto out_double_mount; |
787 | rc = 0; | |
788 | goto out; | |
789 | } | |
790 | ||
089be43e | 791 | if (strcmp(sb->s_type->name, "proc") == 0) |
134509d5 SS |
792 | sbsec->flags |= SE_SBPROC | SE_SBGENFS; |
793 | ||
8e014720 | 794 | if (!strcmp(sb->s_type->name, "debugfs") || |
6a391183 | 795 | !strcmp(sb->s_type->name, "tracefs") || |
8e014720 | 796 | !strcmp(sb->s_type->name, "sysfs") || |
901ef845 AM |
797 | !strcmp(sb->s_type->name, "pstore") || |
798 | !strcmp(sb->s_type->name, "cgroup") || | |
799 | !strcmp(sb->s_type->name, "cgroup2")) | |
134509d5 | 800 | sbsec->flags |= SE_SBGENFS; |
c9180a57 | 801 | |
eb9ae686 DQ |
802 | if (!sbsec->behavior) { |
803 | /* | |
804 | * Determine the labeling behavior to use for this | |
805 | * filesystem type. | |
806 | */ | |
aa8e712c | 807 | rc = security_fs_use(&selinux_state, sb); |
eb9ae686 | 808 | if (rc) { |
c103a91e | 809 | pr_warn("%s: security_fs_use(%s) returned %d\n", |
eb9ae686 DQ |
810 | __func__, sb->s_type->name, rc); |
811 | goto out; | |
812 | } | |
c9180a57 | 813 | } |
aad82892 SF |
814 | |
815 | /* | |
01593d32 SS |
816 | * If this is a user namespace mount and the filesystem type is not |
817 | * explicitly whitelisted, then no contexts are allowed on the command | |
818 | * line and security labels must be ignored. | |
aad82892 | 819 | */ |
01593d32 SS |
820 | if (sb->s_user_ns != &init_user_ns && |
821 | strcmp(sb->s_type->name, "tmpfs") && | |
822 | strcmp(sb->s_type->name, "ramfs") && | |
823 | strcmp(sb->s_type->name, "devpts")) { | |
aad82892 SF |
824 | if (context_sid || fscontext_sid || rootcontext_sid || |
825 | defcontext_sid) { | |
826 | rc = -EACCES; | |
827 | goto out; | |
828 | } | |
829 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { | |
830 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; | |
aa8e712c SS |
831 | rc = security_transition_sid(&selinux_state, |
832 | current_sid(), | |
833 | current_sid(), | |
aad82892 SF |
834 | SECCLASS_FILE, NULL, |
835 | &sbsec->mntpoint_sid); | |
836 | if (rc) | |
837 | goto out; | |
838 | } | |
839 | goto out_set_opts; | |
840 | } | |
841 | ||
c9180a57 EP |
842 | /* sets the context of the superblock for the fs being mounted. */ |
843 | if (fscontext_sid) { | |
275bb41e | 844 | rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); |
1da177e4 | 845 | if (rc) |
c9180a57 | 846 | goto out; |
1da177e4 | 847 | |
c9180a57 | 848 | sbsec->sid = fscontext_sid; |
c312feb2 EP |
849 | } |
850 | ||
851 | /* | |
852 | * Switch to using mount point labeling behavior. | |
853 | * sets the label used on all file below the mountpoint, and will set | |
854 | * the superblock context if not already set. | |
855 | */ | |
eb9ae686 DQ |
856 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) { |
857 | sbsec->behavior = SECURITY_FS_USE_NATIVE; | |
858 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
859 | } | |
860 | ||
c9180a57 EP |
861 | if (context_sid) { |
862 | if (!fscontext_sid) { | |
275bb41e DH |
863 | rc = may_context_mount_sb_relabel(context_sid, sbsec, |
864 | cred); | |
b04ea3ce | 865 | if (rc) |
c9180a57 EP |
866 | goto out; |
867 | sbsec->sid = context_sid; | |
b04ea3ce | 868 | } else { |
275bb41e DH |
869 | rc = may_context_mount_inode_relabel(context_sid, sbsec, |
870 | cred); | |
b04ea3ce | 871 | if (rc) |
c9180a57 | 872 | goto out; |
b04ea3ce | 873 | } |
c9180a57 EP |
874 | if (!rootcontext_sid) |
875 | rootcontext_sid = context_sid; | |
1da177e4 | 876 | |
c9180a57 | 877 | sbsec->mntpoint_sid = context_sid; |
c312feb2 | 878 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; |
1da177e4 LT |
879 | } |
880 | ||
c9180a57 | 881 | if (rootcontext_sid) { |
275bb41e DH |
882 | rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, |
883 | cred); | |
0808925e | 884 | if (rc) |
c9180a57 | 885 | goto out; |
0808925e | 886 | |
c9180a57 | 887 | root_isec->sid = rootcontext_sid; |
6f3be9f5 | 888 | root_isec->initialized = LABEL_INITIALIZED; |
0808925e EP |
889 | } |
890 | ||
c9180a57 | 891 | if (defcontext_sid) { |
eb9ae686 DQ |
892 | if (sbsec->behavior != SECURITY_FS_USE_XATTR && |
893 | sbsec->behavior != SECURITY_FS_USE_NATIVE) { | |
c9180a57 | 894 | rc = -EINVAL; |
c103a91e | 895 | pr_warn("SELinux: defcontext option is " |
c9180a57 EP |
896 | "invalid for this filesystem type\n"); |
897 | goto out; | |
1da177e4 LT |
898 | } |
899 | ||
c9180a57 EP |
900 | if (defcontext_sid != sbsec->def_sid) { |
901 | rc = may_context_mount_inode_relabel(defcontext_sid, | |
275bb41e | 902 | sbsec, cred); |
c9180a57 EP |
903 | if (rc) |
904 | goto out; | |
905 | } | |
1da177e4 | 906 | |
c9180a57 | 907 | sbsec->def_sid = defcontext_sid; |
1da177e4 LT |
908 | } |
909 | ||
aad82892 | 910 | out_set_opts: |
c9180a57 | 911 | rc = sb_finish_set_opts(sb); |
1da177e4 | 912 | out: |
c9180a57 | 913 | mutex_unlock(&sbsec->lock); |
1da177e4 | 914 | return rc; |
c9180a57 EP |
915 | out_double_mount: |
916 | rc = -EINVAL; | |
c103a91e | 917 | pr_warn("SELinux: mount invalid. Same superblock, different " |
bd323655 AV |
918 | "security settings for (dev %s, type %s)\n", sb->s_id, |
919 | sb->s_type->name); | |
c9180a57 | 920 | goto out; |
1da177e4 LT |
921 | } |
922 | ||
094f7b69 JL |
923 | static int selinux_cmp_sb_context(const struct super_block *oldsb, |
924 | const struct super_block *newsb) | |
925 | { | |
926 | struct superblock_security_struct *old = oldsb->s_security; | |
927 | struct superblock_security_struct *new = newsb->s_security; | |
928 | char oldflags = old->flags & SE_MNTMASK; | |
929 | char newflags = new->flags & SE_MNTMASK; | |
930 | ||
931 | if (oldflags != newflags) | |
932 | goto mismatch; | |
933 | if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid) | |
934 | goto mismatch; | |
935 | if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid) | |
936 | goto mismatch; | |
937 | if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid) | |
938 | goto mismatch; | |
939 | if (oldflags & ROOTCONTEXT_MNT) { | |
83da53c5 AG |
940 | struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root); |
941 | struct inode_security_struct *newroot = backing_inode_security(newsb->s_root); | |
094f7b69 JL |
942 | if (oldroot->sid != newroot->sid) |
943 | goto mismatch; | |
944 | } | |
945 | return 0; | |
946 | mismatch: | |
c103a91e | 947 | pr_warn("SELinux: mount invalid. Same superblock, " |
094f7b69 JL |
948 | "different security settings for (dev %s, " |
949 | "type %s)\n", newsb->s_id, newsb->s_type->name); | |
950 | return -EBUSY; | |
951 | } | |
952 | ||
953 | static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, | |
0b4d3452 SM |
954 | struct super_block *newsb, |
955 | unsigned long kern_flags, | |
956 | unsigned long *set_kern_flags) | |
1da177e4 | 957 | { |
0b4d3452 | 958 | int rc = 0; |
c9180a57 EP |
959 | const struct superblock_security_struct *oldsbsec = oldsb->s_security; |
960 | struct superblock_security_struct *newsbsec = newsb->s_security; | |
1da177e4 | 961 | |
c9180a57 EP |
962 | int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); |
963 | int set_context = (oldsbsec->flags & CONTEXT_MNT); | |
964 | int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); | |
1da177e4 | 965 | |
0f5e6420 EP |
966 | /* |
967 | * if the parent was able to be mounted it clearly had no special lsm | |
e8c26255 | 968 | * mount options. thus we can safely deal with this superblock later |
0f5e6420 | 969 | */ |
aa8e712c | 970 | if (!selinux_state.initialized) |
094f7b69 | 971 | return 0; |
c9180a57 | 972 | |
0b4d3452 SM |
973 | /* |
974 | * Specifying internal flags without providing a place to | |
975 | * place the results is not allowed. | |
976 | */ | |
977 | if (kern_flags && !set_kern_flags) | |
978 | return -EINVAL; | |
979 | ||
c9180a57 | 980 | /* how can we clone if the old one wasn't set up?? */ |
0d90a7ec | 981 | BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); |
c9180a57 | 982 | |
094f7b69 | 983 | /* if fs is reusing a sb, make sure that the contexts match */ |
0d90a7ec | 984 | if (newsbsec->flags & SE_SBINITIALIZED) |
094f7b69 | 985 | return selinux_cmp_sb_context(oldsb, newsb); |
5a552617 | 986 | |
c9180a57 EP |
987 | mutex_lock(&newsbsec->lock); |
988 | ||
989 | newsbsec->flags = oldsbsec->flags; | |
990 | ||
991 | newsbsec->sid = oldsbsec->sid; | |
992 | newsbsec->def_sid = oldsbsec->def_sid; | |
993 | newsbsec->behavior = oldsbsec->behavior; | |
994 | ||
0b4d3452 SM |
995 | if (newsbsec->behavior == SECURITY_FS_USE_NATIVE && |
996 | !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) { | |
aa8e712c | 997 | rc = security_fs_use(&selinux_state, newsb); |
0b4d3452 SM |
998 | if (rc) |
999 | goto out; | |
1000 | } | |
1001 | ||
1002 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) { | |
1003 | newsbsec->behavior = SECURITY_FS_USE_NATIVE; | |
1004 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
1005 | } | |
1006 | ||
c9180a57 EP |
1007 | if (set_context) { |
1008 | u32 sid = oldsbsec->mntpoint_sid; | |
1009 | ||
1010 | if (!set_fscontext) | |
1011 | newsbsec->sid = sid; | |
1012 | if (!set_rootcontext) { | |
83da53c5 | 1013 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); |
c9180a57 EP |
1014 | newisec->sid = sid; |
1015 | } | |
1016 | newsbsec->mntpoint_sid = sid; | |
1da177e4 | 1017 | } |
c9180a57 | 1018 | if (set_rootcontext) { |
83da53c5 AG |
1019 | const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root); |
1020 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); | |
1da177e4 | 1021 | |
c9180a57 | 1022 | newisec->sid = oldisec->sid; |
1da177e4 LT |
1023 | } |
1024 | ||
c9180a57 | 1025 | sb_finish_set_opts(newsb); |
0b4d3452 | 1026 | out: |
c9180a57 | 1027 | mutex_unlock(&newsbsec->lock); |
0b4d3452 | 1028 | return rc; |
c9180a57 EP |
1029 | } |
1030 | ||
ba641862 | 1031 | static int selinux_add_opt(int token, const char *s, void **mnt_opts) |
c9180a57 | 1032 | { |
ba641862 | 1033 | struct selinux_mnt_opts *opts = *mnt_opts; |
1da177e4 | 1034 | |
da3d76ab | 1035 | if (token == Opt_seclabel) /* eaten and completely ignored */ |
169d68ef | 1036 | return 0; |
e0007529 | 1037 | |
ba641862 AV |
1038 | if (!opts) { |
1039 | opts = kzalloc(sizeof(struct selinux_mnt_opts), GFP_KERNEL); | |
1040 | if (!opts) | |
1041 | return -ENOMEM; | |
1042 | *mnt_opts = opts; | |
c9180a57 | 1043 | } |
ba641862 AV |
1044 | if (!s) |
1045 | return -ENOMEM; | |
1046 | switch (token) { | |
1047 | case Opt_context: | |
1048 | if (opts->context || opts->defcontext) | |
1049 | goto Einval; | |
1050 | opts->context = s; | |
1051 | break; | |
1052 | case Opt_fscontext: | |
1053 | if (opts->fscontext) | |
1054 | goto Einval; | |
1055 | opts->fscontext = s; | |
1056 | break; | |
1057 | case Opt_rootcontext: | |
1058 | if (opts->rootcontext) | |
1059 | goto Einval; | |
1060 | opts->rootcontext = s; | |
1061 | break; | |
1062 | case Opt_defcontext: | |
1063 | if (opts->context || opts->defcontext) | |
1064 | goto Einval; | |
1065 | opts->defcontext = s; | |
1066 | break; | |
c9180a57 | 1067 | } |
e0007529 | 1068 | return 0; |
ba641862 AV |
1069 | Einval: |
1070 | pr_warn(SEL_MOUNT_FAIL_MSG); | |
ba641862 | 1071 | return -EINVAL; |
1da177e4 | 1072 | } |
e0007529 | 1073 | |
757cbe59 AV |
1074 | static int selinux_add_mnt_opt(const char *option, const char *val, int len, |
1075 | void **mnt_opts) | |
c9180a57 | 1076 | { |
757cbe59 AV |
1077 | int token = Opt_error; |
1078 | int rc, i; | |
e0007529 | 1079 | |
757cbe59 AV |
1080 | for (i = 0; i < ARRAY_SIZE(tokens); i++) { |
1081 | if (strcmp(option, tokens[i].name) == 0) { | |
1082 | token = tokens[i].opt; | |
1083 | break; | |
169d68ef | 1084 | } |
757cbe59 | 1085 | } |
e0007529 | 1086 | |
757cbe59 AV |
1087 | if (token == Opt_error) |
1088 | return -EINVAL; | |
e0007529 | 1089 | |
757cbe59 AV |
1090 | if (token != Opt_seclabel) |
1091 | val = kmemdup_nul(val, len, GFP_KERNEL); | |
1092 | rc = selinux_add_opt(token, val, mnt_opts); | |
1093 | if (unlikely(rc)) { | |
1094 | kfree(val); | |
1095 | if (*mnt_opts) { | |
169d68ef AV |
1096 | selinux_free_mnt_opts(*mnt_opts); |
1097 | *mnt_opts = NULL; | |
1da177e4 | 1098 | } |
1da177e4 | 1099 | } |
e0007529 EP |
1100 | return rc; |
1101 | } | |
1da177e4 | 1102 | |
e3489f89 | 1103 | static int show_sid(struct seq_file *m, u32 sid) |
2069f457 | 1104 | { |
e3489f89 AV |
1105 | char *context = NULL; |
1106 | u32 len; | |
1107 | int rc; | |
11689d47 | 1108 | |
e3489f89 AV |
1109 | rc = security_sid_to_context(&selinux_state, sid, |
1110 | &context, &len); | |
1111 | if (!rc) { | |
1112 | bool has_comma = context && strchr(context, ','); | |
2069f457 | 1113 | |
2069f457 EP |
1114 | if (has_comma) |
1115 | seq_putc(m, '\"'); | |
e3489f89 | 1116 | seq_escape(m, context, "\"\n\\"); |
2069f457 EP |
1117 | if (has_comma) |
1118 | seq_putc(m, '\"'); | |
1119 | } | |
e3489f89 AV |
1120 | kfree(context); |
1121 | return rc; | |
2069f457 EP |
1122 | } |
1123 | ||
1124 | static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) | |
1125 | { | |
e3489f89 | 1126 | struct superblock_security_struct *sbsec = sb->s_security; |
2069f457 EP |
1127 | int rc; |
1128 | ||
e3489f89 AV |
1129 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
1130 | return 0; | |
2069f457 | 1131 | |
e3489f89 AV |
1132 | if (!selinux_state.initialized) |
1133 | return 0; | |
2069f457 | 1134 | |
e3489f89 AV |
1135 | if (sbsec->flags & FSCONTEXT_MNT) { |
1136 | seq_putc(m, ','); | |
1137 | seq_puts(m, FSCONTEXT_STR); | |
1138 | rc = show_sid(m, sbsec->sid); | |
1139 | if (rc) | |
1140 | return rc; | |
1141 | } | |
1142 | if (sbsec->flags & CONTEXT_MNT) { | |
1143 | seq_putc(m, ','); | |
1144 | seq_puts(m, CONTEXT_STR); | |
1145 | rc = show_sid(m, sbsec->mntpoint_sid); | |
1146 | if (rc) | |
1147 | return rc; | |
1148 | } | |
1149 | if (sbsec->flags & DEFCONTEXT_MNT) { | |
1150 | seq_putc(m, ','); | |
1151 | seq_puts(m, DEFCONTEXT_STR); | |
1152 | rc = show_sid(m, sbsec->def_sid); | |
1153 | if (rc) | |
1154 | return rc; | |
1155 | } | |
1156 | if (sbsec->flags & ROOTCONTEXT_MNT) { | |
1157 | struct dentry *root = sbsec->sb->s_root; | |
1158 | struct inode_security_struct *isec = backing_inode_security(root); | |
1159 | seq_putc(m, ','); | |
1160 | seq_puts(m, ROOTCONTEXT_STR); | |
1161 | rc = show_sid(m, isec->sid); | |
1162 | if (rc) | |
1163 | return rc; | |
1164 | } | |
1165 | if (sbsec->flags & SBLABEL_MNT) { | |
1166 | seq_putc(m, ','); | |
1167 | seq_puts(m, LABELSUPP_STR); | |
1168 | } | |
1169 | return 0; | |
2069f457 EP |
1170 | } |
1171 | ||
1da177e4 LT |
1172 | static inline u16 inode_mode_to_security_class(umode_t mode) |
1173 | { | |
1174 | switch (mode & S_IFMT) { | |
1175 | case S_IFSOCK: | |
1176 | return SECCLASS_SOCK_FILE; | |
1177 | case S_IFLNK: | |
1178 | return SECCLASS_LNK_FILE; | |
1179 | case S_IFREG: | |
1180 | return SECCLASS_FILE; | |
1181 | case S_IFBLK: | |
1182 | return SECCLASS_BLK_FILE; | |
1183 | case S_IFDIR: | |
1184 | return SECCLASS_DIR; | |
1185 | case S_IFCHR: | |
1186 | return SECCLASS_CHR_FILE; | |
1187 | case S_IFIFO: | |
1188 | return SECCLASS_FIFO_FILE; | |
1189 | ||
1190 | } | |
1191 | ||
1192 | return SECCLASS_FILE; | |
1193 | } | |
1194 | ||
13402580 JM |
1195 | static inline int default_protocol_stream(int protocol) |
1196 | { | |
1197 | return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); | |
1198 | } | |
1199 | ||
1200 | static inline int default_protocol_dgram(int protocol) | |
1201 | { | |
1202 | return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); | |
1203 | } | |
1204 | ||
1da177e4 LT |
1205 | static inline u16 socket_type_to_security_class(int family, int type, int protocol) |
1206 | { | |
aa8e712c | 1207 | int extsockclass = selinux_policycap_extsockclass(); |
da69a530 | 1208 | |
1da177e4 LT |
1209 | switch (family) { |
1210 | case PF_UNIX: | |
1211 | switch (type) { | |
1212 | case SOCK_STREAM: | |
1213 | case SOCK_SEQPACKET: | |
1214 | return SECCLASS_UNIX_STREAM_SOCKET; | |
1215 | case SOCK_DGRAM: | |
2a764b52 | 1216 | case SOCK_RAW: |
1da177e4 LT |
1217 | return SECCLASS_UNIX_DGRAM_SOCKET; |
1218 | } | |
1219 | break; | |
1220 | case PF_INET: | |
1221 | case PF_INET6: | |
1222 | switch (type) { | |
1223 | case SOCK_STREAM: | |
da69a530 | 1224 | case SOCK_SEQPACKET: |
13402580 JM |
1225 | if (default_protocol_stream(protocol)) |
1226 | return SECCLASS_TCP_SOCKET; | |
da69a530 SS |
1227 | else if (extsockclass && protocol == IPPROTO_SCTP) |
1228 | return SECCLASS_SCTP_SOCKET; | |
13402580 JM |
1229 | else |
1230 | return SECCLASS_RAWIP_SOCKET; | |
1da177e4 | 1231 | case SOCK_DGRAM: |
13402580 JM |
1232 | if (default_protocol_dgram(protocol)) |
1233 | return SECCLASS_UDP_SOCKET; | |
ef37979a SS |
1234 | else if (extsockclass && (protocol == IPPROTO_ICMP || |
1235 | protocol == IPPROTO_ICMPV6)) | |
da69a530 | 1236 | return SECCLASS_ICMP_SOCKET; |
13402580 JM |
1237 | else |
1238 | return SECCLASS_RAWIP_SOCKET; | |
2ee92d46 JM |
1239 | case SOCK_DCCP: |
1240 | return SECCLASS_DCCP_SOCKET; | |
13402580 | 1241 | default: |
1da177e4 LT |
1242 | return SECCLASS_RAWIP_SOCKET; |
1243 | } | |
1244 | break; | |
1245 | case PF_NETLINK: | |
1246 | switch (protocol) { | |
1247 | case NETLINK_ROUTE: | |
1248 | return SECCLASS_NETLINK_ROUTE_SOCKET; | |
7f1fb60c | 1249 | case NETLINK_SOCK_DIAG: |
1da177e4 LT |
1250 | return SECCLASS_NETLINK_TCPDIAG_SOCKET; |
1251 | case NETLINK_NFLOG: | |
1252 | return SECCLASS_NETLINK_NFLOG_SOCKET; | |
1253 | case NETLINK_XFRM: | |
1254 | return SECCLASS_NETLINK_XFRM_SOCKET; | |
1255 | case NETLINK_SELINUX: | |
1256 | return SECCLASS_NETLINK_SELINUX_SOCKET; | |
6c6d2e9b SS |
1257 | case NETLINK_ISCSI: |
1258 | return SECCLASS_NETLINK_ISCSI_SOCKET; | |
1da177e4 LT |
1259 | case NETLINK_AUDIT: |
1260 | return SECCLASS_NETLINK_AUDIT_SOCKET; | |
6c6d2e9b SS |
1261 | case NETLINK_FIB_LOOKUP: |
1262 | return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET; | |
1263 | case NETLINK_CONNECTOR: | |
1264 | return SECCLASS_NETLINK_CONNECTOR_SOCKET; | |
1265 | case NETLINK_NETFILTER: | |
1266 | return SECCLASS_NETLINK_NETFILTER_SOCKET; | |
1da177e4 LT |
1267 | case NETLINK_DNRTMSG: |
1268 | return SECCLASS_NETLINK_DNRT_SOCKET; | |
0c9b7942 JM |
1269 | case NETLINK_KOBJECT_UEVENT: |
1270 | return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; | |
6c6d2e9b SS |
1271 | case NETLINK_GENERIC: |
1272 | return SECCLASS_NETLINK_GENERIC_SOCKET; | |
1273 | case NETLINK_SCSITRANSPORT: | |
1274 | return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET; | |
1275 | case NETLINK_RDMA: | |
1276 | return SECCLASS_NETLINK_RDMA_SOCKET; | |
1277 | case NETLINK_CRYPTO: | |
1278 | return SECCLASS_NETLINK_CRYPTO_SOCKET; | |
1da177e4 LT |
1279 | default: |
1280 | return SECCLASS_NETLINK_SOCKET; | |
1281 | } | |
1282 | case PF_PACKET: | |
1283 | return SECCLASS_PACKET_SOCKET; | |
1284 | case PF_KEY: | |
1285 | return SECCLASS_KEY_SOCKET; | |
3e3ff15e CP |
1286 | case PF_APPLETALK: |
1287 | return SECCLASS_APPLETALK_SOCKET; | |
1da177e4 LT |
1288 | } |
1289 | ||
da69a530 SS |
1290 | if (extsockclass) { |
1291 | switch (family) { | |
1292 | case PF_AX25: | |
1293 | return SECCLASS_AX25_SOCKET; | |
1294 | case PF_IPX: | |
1295 | return SECCLASS_IPX_SOCKET; | |
1296 | case PF_NETROM: | |
1297 | return SECCLASS_NETROM_SOCKET; | |
da69a530 SS |
1298 | case PF_ATMPVC: |
1299 | return SECCLASS_ATMPVC_SOCKET; | |
1300 | case PF_X25: | |
1301 | return SECCLASS_X25_SOCKET; | |
1302 | case PF_ROSE: | |
1303 | return SECCLASS_ROSE_SOCKET; | |
1304 | case PF_DECnet: | |
1305 | return SECCLASS_DECNET_SOCKET; | |
1306 | case PF_ATMSVC: | |
1307 | return SECCLASS_ATMSVC_SOCKET; | |
1308 | case PF_RDS: | |
1309 | return SECCLASS_RDS_SOCKET; | |
1310 | case PF_IRDA: | |
1311 | return SECCLASS_IRDA_SOCKET; | |
1312 | case PF_PPPOX: | |
1313 | return SECCLASS_PPPOX_SOCKET; | |
1314 | case PF_LLC: | |
1315 | return SECCLASS_LLC_SOCKET; | |
da69a530 SS |
1316 | case PF_CAN: |
1317 | return SECCLASS_CAN_SOCKET; | |
1318 | case PF_TIPC: | |
1319 | return SECCLASS_TIPC_SOCKET; | |
1320 | case PF_BLUETOOTH: | |
1321 | return SECCLASS_BLUETOOTH_SOCKET; | |
1322 | case PF_IUCV: | |
1323 | return SECCLASS_IUCV_SOCKET; | |
1324 | case PF_RXRPC: | |
1325 | return SECCLASS_RXRPC_SOCKET; | |
1326 | case PF_ISDN: | |
1327 | return SECCLASS_ISDN_SOCKET; | |
1328 | case PF_PHONET: | |
1329 | return SECCLASS_PHONET_SOCKET; | |
1330 | case PF_IEEE802154: | |
1331 | return SECCLASS_IEEE802154_SOCKET; | |
1332 | case PF_CAIF: | |
1333 | return SECCLASS_CAIF_SOCKET; | |
1334 | case PF_ALG: | |
1335 | return SECCLASS_ALG_SOCKET; | |
1336 | case PF_NFC: | |
1337 | return SECCLASS_NFC_SOCKET; | |
1338 | case PF_VSOCK: | |
1339 | return SECCLASS_VSOCK_SOCKET; | |
1340 | case PF_KCM: | |
1341 | return SECCLASS_KCM_SOCKET; | |
1342 | case PF_QIPCRTR: | |
1343 | return SECCLASS_QIPCRTR_SOCKET; | |
3051bf36 LT |
1344 | case PF_SMC: |
1345 | return SECCLASS_SMC_SOCKET; | |
68e8b849 BT |
1346 | case PF_XDP: |
1347 | return SECCLASS_XDP_SOCKET; | |
1348 | #if PF_MAX > 45 | |
da69a530 SS |
1349 | #error New address family defined, please update this function. |
1350 | #endif | |
1351 | } | |
1352 | } | |
1353 | ||
1da177e4 LT |
1354 | return SECCLASS_SOCKET; |
1355 | } | |
1356 | ||
134509d5 SS |
1357 | static int selinux_genfs_get_sid(struct dentry *dentry, |
1358 | u16 tclass, | |
1359 | u16 flags, | |
1360 | u32 *sid) | |
1da177e4 | 1361 | { |
8e6c9693 | 1362 | int rc; |
fc64005c | 1363 | struct super_block *sb = dentry->d_sb; |
8e6c9693 | 1364 | char *buffer, *path; |
1da177e4 | 1365 | |
828dfe1d | 1366 | buffer = (char *)__get_free_page(GFP_KERNEL); |
1da177e4 LT |
1367 | if (!buffer) |
1368 | return -ENOMEM; | |
1369 | ||
8e6c9693 LAG |
1370 | path = dentry_path_raw(dentry, buffer, PAGE_SIZE); |
1371 | if (IS_ERR(path)) | |
1372 | rc = PTR_ERR(path); | |
1373 | else { | |
134509d5 SS |
1374 | if (flags & SE_SBPROC) { |
1375 | /* each process gets a /proc/PID/ entry. Strip off the | |
1376 | * PID part to get a valid selinux labeling. | |
1377 | * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ | |
1378 | while (path[1] >= '0' && path[1] <= '9') { | |
1379 | path[1] = '/'; | |
1380 | path++; | |
1381 | } | |
8e6c9693 | 1382 | } |
aa8e712c SS |
1383 | rc = security_genfs_sid(&selinux_state, sb->s_type->name, |
1384 | path, tclass, sid); | |
7bb185ed SS |
1385 | if (rc == -ENOENT) { |
1386 | /* No match in policy, mark as unlabeled. */ | |
1387 | *sid = SECINITSID_UNLABELED; | |
1388 | rc = 0; | |
1389 | } | |
1da177e4 | 1390 | } |
1da177e4 LT |
1391 | free_page((unsigned long)buffer); |
1392 | return rc; | |
1393 | } | |
1da177e4 LT |
1394 | |
1395 | /* The inode's security attributes must be initialized before first use. */ | |
1396 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) | |
1397 | { | |
1398 | struct superblock_security_struct *sbsec = NULL; | |
1399 | struct inode_security_struct *isec = inode->i_security; | |
9287aed2 AG |
1400 | u32 task_sid, sid = 0; |
1401 | u16 sclass; | |
1da177e4 LT |
1402 | struct dentry *dentry; |
1403 | #define INITCONTEXTLEN 255 | |
1404 | char *context = NULL; | |
1405 | unsigned len = 0; | |
1406 | int rc = 0; | |
1da177e4 | 1407 | |
6f3be9f5 | 1408 | if (isec->initialized == LABEL_INITIALIZED) |
13457d07 | 1409 | return 0; |
1da177e4 | 1410 | |
9287aed2 | 1411 | spin_lock(&isec->lock); |
6f3be9f5 | 1412 | if (isec->initialized == LABEL_INITIALIZED) |
23970741 | 1413 | goto out_unlock; |
1da177e4 | 1414 | |
13457d07 AG |
1415 | if (isec->sclass == SECCLASS_FILE) |
1416 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
1417 | ||
1da177e4 | 1418 | sbsec = inode->i_sb->s_security; |
0d90a7ec | 1419 | if (!(sbsec->flags & SE_SBINITIALIZED)) { |
1da177e4 LT |
1420 | /* Defer initialization until selinux_complete_init, |
1421 | after the initial policy is loaded and the security | |
1422 | server is ready to handle calls. */ | |
1423 | spin_lock(&sbsec->isec_lock); | |
1424 | if (list_empty(&isec->list)) | |
1425 | list_add(&isec->list, &sbsec->isec_head); | |
1426 | spin_unlock(&sbsec->isec_lock); | |
23970741 | 1427 | goto out_unlock; |
1da177e4 LT |
1428 | } |
1429 | ||
9287aed2 AG |
1430 | sclass = isec->sclass; |
1431 | task_sid = isec->task_sid; | |
1432 | sid = isec->sid; | |
1433 | isec->initialized = LABEL_PENDING; | |
1434 | spin_unlock(&isec->lock); | |
1435 | ||
1da177e4 | 1436 | switch (sbsec->behavior) { |
eb9ae686 DQ |
1437 | case SECURITY_FS_USE_NATIVE: |
1438 | break; | |
1da177e4 | 1439 | case SECURITY_FS_USE_XATTR: |
5d6c3191 | 1440 | if (!(inode->i_opflags & IOP_XATTR)) { |
9287aed2 | 1441 | sid = sbsec->def_sid; |
1da177e4 LT |
1442 | break; |
1443 | } | |
1da177e4 LT |
1444 | /* Need a dentry, since the xattr API requires one. |
1445 | Life would be simpler if we could just pass the inode. */ | |
1446 | if (opt_dentry) { | |
1447 | /* Called from d_instantiate or d_splice_alias. */ | |
1448 | dentry = dget(opt_dentry); | |
1449 | } else { | |
b127125d AV |
1450 | /* |
1451 | * Called from selinux_complete_init, try to find a dentry. | |
1452 | * Some filesystems really want a connected one, so try | |
1453 | * that first. We could split SECURITY_FS_USE_XATTR in | |
1454 | * two, depending upon that... | |
1455 | */ | |
1da177e4 | 1456 | dentry = d_find_alias(inode); |
b127125d AV |
1457 | if (!dentry) |
1458 | dentry = d_find_any_alias(inode); | |
1da177e4 LT |
1459 | } |
1460 | if (!dentry) { | |
df7f54c0 EP |
1461 | /* |
1462 | * this is can be hit on boot when a file is accessed | |
1463 | * before the policy is loaded. When we load policy we | |
1464 | * may find inodes that have no dentry on the | |
1465 | * sbsec->isec_head list. No reason to complain as these | |
1466 | * will get fixed up the next time we go through | |
1467 | * inode_doinit with a dentry, before these inodes could | |
1468 | * be used again by userspace. | |
1469 | */ | |
9287aed2 | 1470 | goto out; |
1da177e4 LT |
1471 | } |
1472 | ||
1473 | len = INITCONTEXTLEN; | |
4cb912f1 | 1474 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1475 | if (!context) { |
1476 | rc = -ENOMEM; | |
1477 | dput(dentry); | |
9287aed2 | 1478 | goto out; |
1da177e4 | 1479 | } |
4cb912f1 | 1480 | context[len] = '\0'; |
5d6c3191 | 1481 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 | 1482 | if (rc == -ERANGE) { |
314dabb8 JM |
1483 | kfree(context); |
1484 | ||
1da177e4 | 1485 | /* Need a larger buffer. Query for the right size. */ |
5d6c3191 | 1486 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0); |
1da177e4 LT |
1487 | if (rc < 0) { |
1488 | dput(dentry); | |
9287aed2 | 1489 | goto out; |
1da177e4 | 1490 | } |
1da177e4 | 1491 | len = rc; |
4cb912f1 | 1492 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1493 | if (!context) { |
1494 | rc = -ENOMEM; | |
1495 | dput(dentry); | |
9287aed2 | 1496 | goto out; |
1da177e4 | 1497 | } |
4cb912f1 | 1498 | context[len] = '\0'; |
5d6c3191 | 1499 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 LT |
1500 | } |
1501 | dput(dentry); | |
1502 | if (rc < 0) { | |
1503 | if (rc != -ENODATA) { | |
c103a91e | 1504 | pr_warn("SELinux: %s: getxattr returned " |
dd6f953a | 1505 | "%d for dev=%s ino=%ld\n", __func__, |
1da177e4 LT |
1506 | -rc, inode->i_sb->s_id, inode->i_ino); |
1507 | kfree(context); | |
9287aed2 | 1508 | goto out; |
1da177e4 LT |
1509 | } |
1510 | /* Map ENODATA to the default file SID */ | |
1511 | sid = sbsec->def_sid; | |
1512 | rc = 0; | |
1513 | } else { | |
aa8e712c SS |
1514 | rc = security_context_to_sid_default(&selinux_state, |
1515 | context, rc, &sid, | |
869ab514 SS |
1516 | sbsec->def_sid, |
1517 | GFP_NOFS); | |
1da177e4 | 1518 | if (rc) { |
4ba0a8ad EP |
1519 | char *dev = inode->i_sb->s_id; |
1520 | unsigned long ino = inode->i_ino; | |
1521 | ||
1522 | if (rc == -EINVAL) { | |
1523 | if (printk_ratelimit()) | |
c103a91e | 1524 | pr_notice("SELinux: inode=%lu on dev=%s was found to have an invalid " |
4ba0a8ad EP |
1525 | "context=%s. This indicates you may need to relabel the inode or the " |
1526 | "filesystem in question.\n", ino, dev, context); | |
1527 | } else { | |
c103a91e | 1528 | pr_warn("SELinux: %s: context_to_sid(%s) " |
4ba0a8ad EP |
1529 | "returned %d for dev=%s ino=%ld\n", |
1530 | __func__, context, -rc, dev, ino); | |
1531 | } | |
1da177e4 LT |
1532 | kfree(context); |
1533 | /* Leave with the unlabeled SID */ | |
1534 | rc = 0; | |
1535 | break; | |
1536 | } | |
1537 | } | |
1538 | kfree(context); | |
1da177e4 LT |
1539 | break; |
1540 | case SECURITY_FS_USE_TASK: | |
9287aed2 | 1541 | sid = task_sid; |
1da177e4 LT |
1542 | break; |
1543 | case SECURITY_FS_USE_TRANS: | |
1544 | /* Default to the fs SID. */ | |
9287aed2 | 1545 | sid = sbsec->sid; |
1da177e4 LT |
1546 | |
1547 | /* Try to obtain a transition SID. */ | |
aa8e712c SS |
1548 | rc = security_transition_sid(&selinux_state, task_sid, sid, |
1549 | sclass, NULL, &sid); | |
1da177e4 | 1550 | if (rc) |
9287aed2 | 1551 | goto out; |
1da177e4 | 1552 | break; |
c312feb2 | 1553 | case SECURITY_FS_USE_MNTPOINT: |
9287aed2 | 1554 | sid = sbsec->mntpoint_sid; |
c312feb2 | 1555 | break; |
1da177e4 | 1556 | default: |
c312feb2 | 1557 | /* Default to the fs superblock SID. */ |
9287aed2 | 1558 | sid = sbsec->sid; |
1da177e4 | 1559 | |
134509d5 | 1560 | if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) { |
f64410ec PM |
1561 | /* We must have a dentry to determine the label on |
1562 | * procfs inodes */ | |
b127125d | 1563 | if (opt_dentry) { |
f64410ec PM |
1564 | /* Called from d_instantiate or |
1565 | * d_splice_alias. */ | |
1566 | dentry = dget(opt_dentry); | |
b127125d | 1567 | } else { |
f64410ec | 1568 | /* Called from selinux_complete_init, try to |
b127125d AV |
1569 | * find a dentry. Some filesystems really want |
1570 | * a connected one, so try that first. | |
1571 | */ | |
f64410ec | 1572 | dentry = d_find_alias(inode); |
b127125d AV |
1573 | if (!dentry) |
1574 | dentry = d_find_any_alias(inode); | |
1575 | } | |
f64410ec PM |
1576 | /* |
1577 | * This can be hit on boot when a file is accessed | |
1578 | * before the policy is loaded. When we load policy we | |
1579 | * may find inodes that have no dentry on the | |
1580 | * sbsec->isec_head list. No reason to complain as | |
1581 | * these will get fixed up the next time we go through | |
1582 | * inode_doinit() with a dentry, before these inodes | |
1583 | * could be used again by userspace. | |
1584 | */ | |
1585 | if (!dentry) | |
9287aed2 AG |
1586 | goto out; |
1587 | rc = selinux_genfs_get_sid(dentry, sclass, | |
134509d5 | 1588 | sbsec->flags, &sid); |
f64410ec PM |
1589 | dput(dentry); |
1590 | if (rc) | |
9287aed2 | 1591 | goto out; |
1da177e4 LT |
1592 | } |
1593 | break; | |
1594 | } | |
1595 | ||
9287aed2 AG |
1596 | out: |
1597 | spin_lock(&isec->lock); | |
1598 | if (isec->initialized == LABEL_PENDING) { | |
1599 | if (!sid || rc) { | |
1600 | isec->initialized = LABEL_INVALID; | |
1601 | goto out_unlock; | |
1602 | } | |
1603 | ||
1604 | isec->initialized = LABEL_INITIALIZED; | |
1605 | isec->sid = sid; | |
1606 | } | |
1da177e4 | 1607 | |
23970741 | 1608 | out_unlock: |
9287aed2 | 1609 | spin_unlock(&isec->lock); |
1da177e4 LT |
1610 | return rc; |
1611 | } | |
1612 | ||
1613 | /* Convert a Linux signal to an access vector. */ | |
1614 | static inline u32 signal_to_av(int sig) | |
1615 | { | |
1616 | u32 perm = 0; | |
1617 | ||
1618 | switch (sig) { | |
1619 | case SIGCHLD: | |
1620 | /* Commonly granted from child to parent. */ | |
1621 | perm = PROCESS__SIGCHLD; | |
1622 | break; | |
1623 | case SIGKILL: | |
1624 | /* Cannot be caught or ignored */ | |
1625 | perm = PROCESS__SIGKILL; | |
1626 | break; | |
1627 | case SIGSTOP: | |
1628 | /* Cannot be caught or ignored */ | |
1629 | perm = PROCESS__SIGSTOP; | |
1630 | break; | |
1631 | default: | |
1632 | /* All other signals. */ | |
1633 | perm = PROCESS__SIGNAL; | |
1634 | break; | |
1635 | } | |
1636 | ||
1637 | return perm; | |
1638 | } | |
1639 | ||
b68e418c SS |
1640 | #if CAP_LAST_CAP > 63 |
1641 | #error Fix SELinux to handle capabilities > 63. | |
1642 | #endif | |
1643 | ||
1da177e4 | 1644 | /* Check whether a task is allowed to use a capability. */ |
6a9de491 | 1645 | static int cred_has_capability(const struct cred *cred, |
8e4ff6f2 | 1646 | int cap, int audit, bool initns) |
1da177e4 | 1647 | { |
2bf49690 | 1648 | struct common_audit_data ad; |
06112163 | 1649 | struct av_decision avd; |
b68e418c | 1650 | u16 sclass; |
3699c53c | 1651 | u32 sid = cred_sid(cred); |
b68e418c | 1652 | u32 av = CAP_TO_MASK(cap); |
06112163 | 1653 | int rc; |
1da177e4 | 1654 | |
50c205f5 | 1655 | ad.type = LSM_AUDIT_DATA_CAP; |
1da177e4 LT |
1656 | ad.u.cap = cap; |
1657 | ||
b68e418c SS |
1658 | switch (CAP_TO_INDEX(cap)) { |
1659 | case 0: | |
8e4ff6f2 | 1660 | sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS; |
b68e418c SS |
1661 | break; |
1662 | case 1: | |
8e4ff6f2 | 1663 | sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS; |
b68e418c SS |
1664 | break; |
1665 | default: | |
c103a91e | 1666 | pr_err("SELinux: out of range capability %d\n", cap); |
b68e418c | 1667 | BUG(); |
a35c6c83 | 1668 | return -EINVAL; |
b68e418c | 1669 | } |
06112163 | 1670 | |
6b6bc620 SS |
1671 | rc = avc_has_perm_noaudit(&selinux_state, |
1672 | sid, sid, sclass, av, 0, &avd); | |
9ade0cf4 | 1673 | if (audit == SECURITY_CAP_AUDIT) { |
6b6bc620 SS |
1674 | int rc2 = avc_audit(&selinux_state, |
1675 | sid, sid, sclass, av, &avd, rc, &ad, 0); | |
9ade0cf4 EP |
1676 | if (rc2) |
1677 | return rc2; | |
1678 | } | |
06112163 | 1679 | return rc; |
1da177e4 LT |
1680 | } |
1681 | ||
1da177e4 LT |
1682 | /* Check whether a task has a particular permission to an inode. |
1683 | The 'adp' parameter is optional and allows other audit | |
1684 | data to be passed (e.g. the dentry). */ | |
88e67f3b | 1685 | static int inode_has_perm(const struct cred *cred, |
1da177e4 LT |
1686 | struct inode *inode, |
1687 | u32 perms, | |
19e49834 | 1688 | struct common_audit_data *adp) |
1da177e4 | 1689 | { |
1da177e4 | 1690 | struct inode_security_struct *isec; |
275bb41e | 1691 | u32 sid; |
1da177e4 | 1692 | |
e0e81739 DH |
1693 | validate_creds(cred); |
1694 | ||
828dfe1d | 1695 | if (unlikely(IS_PRIVATE(inode))) |
bbaca6c2 SS |
1696 | return 0; |
1697 | ||
88e67f3b | 1698 | sid = cred_sid(cred); |
1da177e4 LT |
1699 | isec = inode->i_security; |
1700 | ||
6b6bc620 SS |
1701 | return avc_has_perm(&selinux_state, |
1702 | sid, isec->sid, isec->sclass, perms, adp); | |
1da177e4 LT |
1703 | } |
1704 | ||
1705 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1706 | the dentry to help the auditing code to more easily generate the | |
1707 | pathname if needed. */ | |
88e67f3b | 1708 | static inline int dentry_has_perm(const struct cred *cred, |
1da177e4 LT |
1709 | struct dentry *dentry, |
1710 | u32 av) | |
1711 | { | |
c6f493d6 | 1712 | struct inode *inode = d_backing_inode(dentry); |
2bf49690 | 1713 | struct common_audit_data ad; |
88e67f3b | 1714 | |
50c205f5 | 1715 | ad.type = LSM_AUDIT_DATA_DENTRY; |
2875fa00 | 1716 | ad.u.dentry = dentry; |
5d226df4 | 1717 | __inode_security_revalidate(inode, dentry, true); |
19e49834 | 1718 | return inode_has_perm(cred, inode, av, &ad); |
2875fa00 EP |
1719 | } |
1720 | ||
1721 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1722 | the path to help the auditing code to more easily generate the | |
1723 | pathname if needed. */ | |
1724 | static inline int path_has_perm(const struct cred *cred, | |
3f7036a0 | 1725 | const struct path *path, |
2875fa00 EP |
1726 | u32 av) |
1727 | { | |
c6f493d6 | 1728 | struct inode *inode = d_backing_inode(path->dentry); |
2875fa00 EP |
1729 | struct common_audit_data ad; |
1730 | ||
50c205f5 | 1731 | ad.type = LSM_AUDIT_DATA_PATH; |
2875fa00 | 1732 | ad.u.path = *path; |
5d226df4 | 1733 | __inode_security_revalidate(inode, path->dentry, true); |
19e49834 | 1734 | return inode_has_perm(cred, inode, av, &ad); |
1da177e4 LT |
1735 | } |
1736 | ||
13f8e981 DH |
1737 | /* Same as path_has_perm, but uses the inode from the file struct. */ |
1738 | static inline int file_path_has_perm(const struct cred *cred, | |
1739 | struct file *file, | |
1740 | u32 av) | |
1741 | { | |
1742 | struct common_audit_data ad; | |
1743 | ||
43af5de7 VG |
1744 | ad.type = LSM_AUDIT_DATA_FILE; |
1745 | ad.u.file = file; | |
19e49834 | 1746 | return inode_has_perm(cred, file_inode(file), av, &ad); |
13f8e981 DH |
1747 | } |
1748 | ||
f66e448c CF |
1749 | #ifdef CONFIG_BPF_SYSCALL |
1750 | static int bpf_fd_pass(struct file *file, u32 sid); | |
1751 | #endif | |
1752 | ||
1da177e4 LT |
1753 | /* Check whether a task can use an open file descriptor to |
1754 | access an inode in a given way. Check access to the | |
1755 | descriptor itself, and then use dentry_has_perm to | |
1756 | check a particular permission to the file. | |
1757 | Access to the descriptor is implicitly granted if it | |
1758 | has the same SID as the process. If av is zero, then | |
1759 | access to the file is not checked, e.g. for cases | |
1760 | where only the descriptor is affected like seek. */ | |
88e67f3b DH |
1761 | static int file_has_perm(const struct cred *cred, |
1762 | struct file *file, | |
1763 | u32 av) | |
1da177e4 | 1764 | { |
1da177e4 | 1765 | struct file_security_struct *fsec = file->f_security; |
496ad9aa | 1766 | struct inode *inode = file_inode(file); |
2bf49690 | 1767 | struct common_audit_data ad; |
88e67f3b | 1768 | u32 sid = cred_sid(cred); |
1da177e4 LT |
1769 | int rc; |
1770 | ||
43af5de7 VG |
1771 | ad.type = LSM_AUDIT_DATA_FILE; |
1772 | ad.u.file = file; | |
1da177e4 | 1773 | |
275bb41e | 1774 | if (sid != fsec->sid) { |
6b6bc620 SS |
1775 | rc = avc_has_perm(&selinux_state, |
1776 | sid, fsec->sid, | |
1da177e4 LT |
1777 | SECCLASS_FD, |
1778 | FD__USE, | |
1779 | &ad); | |
1780 | if (rc) | |
88e67f3b | 1781 | goto out; |
1da177e4 LT |
1782 | } |
1783 | ||
f66e448c CF |
1784 | #ifdef CONFIG_BPF_SYSCALL |
1785 | rc = bpf_fd_pass(file, cred_sid(cred)); | |
1786 | if (rc) | |
1787 | return rc; | |
1788 | #endif | |
1789 | ||
1da177e4 | 1790 | /* av is zero if only checking access to the descriptor. */ |
88e67f3b | 1791 | rc = 0; |
1da177e4 | 1792 | if (av) |
19e49834 | 1793 | rc = inode_has_perm(cred, inode, av, &ad); |
1da177e4 | 1794 | |
88e67f3b DH |
1795 | out: |
1796 | return rc; | |
1da177e4 LT |
1797 | } |
1798 | ||
c3c188b2 DH |
1799 | /* |
1800 | * Determine the label for an inode that might be unioned. | |
1801 | */ | |
c957f6df VG |
1802 | static int |
1803 | selinux_determine_inode_label(const struct task_security_struct *tsec, | |
1804 | struct inode *dir, | |
1805 | const struct qstr *name, u16 tclass, | |
1806 | u32 *_new_isid) | |
c3c188b2 DH |
1807 | { |
1808 | const struct superblock_security_struct *sbsec = dir->i_sb->s_security; | |
c3c188b2 DH |
1809 | |
1810 | if ((sbsec->flags & SE_SBINITIALIZED) && | |
1811 | (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { | |
1812 | *_new_isid = sbsec->mntpoint_sid; | |
1813 | } else if ((sbsec->flags & SBLABEL_MNT) && | |
1814 | tsec->create_sid) { | |
1815 | *_new_isid = tsec->create_sid; | |
1816 | } else { | |
20cdef8d | 1817 | const struct inode_security_struct *dsec = inode_security(dir); |
aa8e712c SS |
1818 | return security_transition_sid(&selinux_state, tsec->sid, |
1819 | dsec->sid, tclass, | |
c3c188b2 DH |
1820 | name, _new_isid); |
1821 | } | |
1822 | ||
1823 | return 0; | |
1824 | } | |
1825 | ||
1da177e4 LT |
1826 | /* Check whether a task can create a file. */ |
1827 | static int may_create(struct inode *dir, | |
1828 | struct dentry *dentry, | |
1829 | u16 tclass) | |
1830 | { | |
5fb49870 | 1831 | const struct task_security_struct *tsec = current_security(); |
1da177e4 LT |
1832 | struct inode_security_struct *dsec; |
1833 | struct superblock_security_struct *sbsec; | |
275bb41e | 1834 | u32 sid, newsid; |
2bf49690 | 1835 | struct common_audit_data ad; |
1da177e4 LT |
1836 | int rc; |
1837 | ||
83da53c5 | 1838 | dsec = inode_security(dir); |
1da177e4 LT |
1839 | sbsec = dir->i_sb->s_security; |
1840 | ||
275bb41e | 1841 | sid = tsec->sid; |
275bb41e | 1842 | |
50c205f5 | 1843 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1844 | ad.u.dentry = dentry; |
1da177e4 | 1845 | |
6b6bc620 SS |
1846 | rc = avc_has_perm(&selinux_state, |
1847 | sid, dsec->sid, SECCLASS_DIR, | |
1da177e4 LT |
1848 | DIR__ADD_NAME | DIR__SEARCH, |
1849 | &ad); | |
1850 | if (rc) | |
1851 | return rc; | |
1852 | ||
c957f6df VG |
1853 | rc = selinux_determine_inode_label(current_security(), dir, |
1854 | &dentry->d_name, tclass, &newsid); | |
c3c188b2 DH |
1855 | if (rc) |
1856 | return rc; | |
1da177e4 | 1857 | |
6b6bc620 SS |
1858 | rc = avc_has_perm(&selinux_state, |
1859 | sid, newsid, tclass, FILE__CREATE, &ad); | |
1da177e4 LT |
1860 | if (rc) |
1861 | return rc; | |
1862 | ||
6b6bc620 SS |
1863 | return avc_has_perm(&selinux_state, |
1864 | newsid, sbsec->sid, | |
1da177e4 LT |
1865 | SECCLASS_FILESYSTEM, |
1866 | FILESYSTEM__ASSOCIATE, &ad); | |
1867 | } | |
1868 | ||
828dfe1d EP |
1869 | #define MAY_LINK 0 |
1870 | #define MAY_UNLINK 1 | |
1871 | #define MAY_RMDIR 2 | |
1da177e4 LT |
1872 | |
1873 | /* Check whether a task can link, unlink, or rmdir a file/directory. */ | |
1874 | static int may_link(struct inode *dir, | |
1875 | struct dentry *dentry, | |
1876 | int kind) | |
1877 | ||
1878 | { | |
1da177e4 | 1879 | struct inode_security_struct *dsec, *isec; |
2bf49690 | 1880 | struct common_audit_data ad; |
275bb41e | 1881 | u32 sid = current_sid(); |
1da177e4 LT |
1882 | u32 av; |
1883 | int rc; | |
1884 | ||
83da53c5 AG |
1885 | dsec = inode_security(dir); |
1886 | isec = backing_inode_security(dentry); | |
1da177e4 | 1887 | |
50c205f5 | 1888 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1889 | ad.u.dentry = dentry; |
1da177e4 LT |
1890 | |
1891 | av = DIR__SEARCH; | |
1892 | av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); | |
6b6bc620 SS |
1893 | rc = avc_has_perm(&selinux_state, |
1894 | sid, dsec->sid, SECCLASS_DIR, av, &ad); | |
1da177e4 LT |
1895 | if (rc) |
1896 | return rc; | |
1897 | ||
1898 | switch (kind) { | |
1899 | case MAY_LINK: | |
1900 | av = FILE__LINK; | |
1901 | break; | |
1902 | case MAY_UNLINK: | |
1903 | av = FILE__UNLINK; | |
1904 | break; | |
1905 | case MAY_RMDIR: | |
1906 | av = DIR__RMDIR; | |
1907 | break; | |
1908 | default: | |
c103a91e | 1909 | pr_warn("SELinux: %s: unrecognized kind %d\n", |
744ba35e | 1910 | __func__, kind); |
1da177e4 LT |
1911 | return 0; |
1912 | } | |
1913 | ||
6b6bc620 SS |
1914 | rc = avc_has_perm(&selinux_state, |
1915 | sid, isec->sid, isec->sclass, av, &ad); | |
1da177e4 LT |
1916 | return rc; |
1917 | } | |
1918 | ||
1919 | static inline int may_rename(struct inode *old_dir, | |
1920 | struct dentry *old_dentry, | |
1921 | struct inode *new_dir, | |
1922 | struct dentry *new_dentry) | |
1923 | { | |
1da177e4 | 1924 | struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; |
2bf49690 | 1925 | struct common_audit_data ad; |
275bb41e | 1926 | u32 sid = current_sid(); |
1da177e4 LT |
1927 | u32 av; |
1928 | int old_is_dir, new_is_dir; | |
1929 | int rc; | |
1930 | ||
83da53c5 AG |
1931 | old_dsec = inode_security(old_dir); |
1932 | old_isec = backing_inode_security(old_dentry); | |
e36cb0b8 | 1933 | old_is_dir = d_is_dir(old_dentry); |
83da53c5 | 1934 | new_dsec = inode_security(new_dir); |
1da177e4 | 1935 | |
50c205f5 | 1936 | ad.type = LSM_AUDIT_DATA_DENTRY; |
1da177e4 | 1937 | |
a269434d | 1938 | ad.u.dentry = old_dentry; |
6b6bc620 SS |
1939 | rc = avc_has_perm(&selinux_state, |
1940 | sid, old_dsec->sid, SECCLASS_DIR, | |
1da177e4 LT |
1941 | DIR__REMOVE_NAME | DIR__SEARCH, &ad); |
1942 | if (rc) | |
1943 | return rc; | |
6b6bc620 SS |
1944 | rc = avc_has_perm(&selinux_state, |
1945 | sid, old_isec->sid, | |
1da177e4 LT |
1946 | old_isec->sclass, FILE__RENAME, &ad); |
1947 | if (rc) | |
1948 | return rc; | |
1949 | if (old_is_dir && new_dir != old_dir) { | |
6b6bc620 SS |
1950 | rc = avc_has_perm(&selinux_state, |
1951 | sid, old_isec->sid, | |
1da177e4 LT |
1952 | old_isec->sclass, DIR__REPARENT, &ad); |
1953 | if (rc) | |
1954 | return rc; | |
1955 | } | |
1956 | ||
a269434d | 1957 | ad.u.dentry = new_dentry; |
1da177e4 | 1958 | av = DIR__ADD_NAME | DIR__SEARCH; |
2c616d4d | 1959 | if (d_is_positive(new_dentry)) |
1da177e4 | 1960 | av |= DIR__REMOVE_NAME; |
6b6bc620 SS |
1961 | rc = avc_has_perm(&selinux_state, |
1962 | sid, new_dsec->sid, SECCLASS_DIR, av, &ad); | |
1da177e4 LT |
1963 | if (rc) |
1964 | return rc; | |
2c616d4d | 1965 | if (d_is_positive(new_dentry)) { |
83da53c5 | 1966 | new_isec = backing_inode_security(new_dentry); |
e36cb0b8 | 1967 | new_is_dir = d_is_dir(new_dentry); |
6b6bc620 SS |
1968 | rc = avc_has_perm(&selinux_state, |
1969 | sid, new_isec->sid, | |
1da177e4 LT |
1970 | new_isec->sclass, |
1971 | (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); | |
1972 | if (rc) | |
1973 | return rc; | |
1974 | } | |
1975 | ||
1976 | return 0; | |
1977 | } | |
1978 | ||
1979 | /* Check whether a task can perform a filesystem operation. */ | |
88e67f3b | 1980 | static int superblock_has_perm(const struct cred *cred, |
1da177e4 LT |
1981 | struct super_block *sb, |
1982 | u32 perms, | |
2bf49690 | 1983 | struct common_audit_data *ad) |
1da177e4 | 1984 | { |
1da177e4 | 1985 | struct superblock_security_struct *sbsec; |
88e67f3b | 1986 | u32 sid = cred_sid(cred); |
1da177e4 | 1987 | |
1da177e4 | 1988 | sbsec = sb->s_security; |
6b6bc620 SS |
1989 | return avc_has_perm(&selinux_state, |
1990 | sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); | |
1da177e4 LT |
1991 | } |
1992 | ||
1993 | /* Convert a Linux mode and permission mask to an access vector. */ | |
1994 | static inline u32 file_mask_to_av(int mode, int mask) | |
1995 | { | |
1996 | u32 av = 0; | |
1997 | ||
dba19c60 | 1998 | if (!S_ISDIR(mode)) { |
1da177e4 LT |
1999 | if (mask & MAY_EXEC) |
2000 | av |= FILE__EXECUTE; | |
2001 | if (mask & MAY_READ) | |
2002 | av |= FILE__READ; | |
2003 | ||
2004 | if (mask & MAY_APPEND) | |
2005 | av |= FILE__APPEND; | |
2006 | else if (mask & MAY_WRITE) | |
2007 | av |= FILE__WRITE; | |
2008 | ||
2009 | } else { | |
2010 | if (mask & MAY_EXEC) | |
2011 | av |= DIR__SEARCH; | |
2012 | if (mask & MAY_WRITE) | |
2013 | av |= DIR__WRITE; | |
2014 | if (mask & MAY_READ) | |
2015 | av |= DIR__READ; | |
2016 | } | |
2017 | ||
2018 | return av; | |
2019 | } | |
2020 | ||
8b6a5a37 EP |
2021 | /* Convert a Linux file to an access vector. */ |
2022 | static inline u32 file_to_av(struct file *file) | |
2023 | { | |
2024 | u32 av = 0; | |
2025 | ||
2026 | if (file->f_mode & FMODE_READ) | |
2027 | av |= FILE__READ; | |
2028 | if (file->f_mode & FMODE_WRITE) { | |
2029 | if (file->f_flags & O_APPEND) | |
2030 | av |= FILE__APPEND; | |
2031 | else | |
2032 | av |= FILE__WRITE; | |
2033 | } | |
2034 | if (!av) { | |
2035 | /* | |
2036 | * Special file opened with flags 3 for ioctl-only use. | |
2037 | */ | |
2038 | av = FILE__IOCTL; | |
2039 | } | |
2040 | ||
2041 | return av; | |
2042 | } | |
2043 | ||
b0c636b9 | 2044 | /* |
8b6a5a37 | 2045 | * Convert a file to an access vector and include the correct open |
b0c636b9 EP |
2046 | * open permission. |
2047 | */ | |
8b6a5a37 | 2048 | static inline u32 open_file_to_av(struct file *file) |
b0c636b9 | 2049 | { |
8b6a5a37 | 2050 | u32 av = file_to_av(file); |
ccb54478 | 2051 | struct inode *inode = file_inode(file); |
b0c636b9 | 2052 | |
aa8e712c SS |
2053 | if (selinux_policycap_openperm() && |
2054 | inode->i_sb->s_magic != SOCKFS_MAGIC) | |
49b7b8de EP |
2055 | av |= FILE__OPEN; |
2056 | ||
b0c636b9 EP |
2057 | return av; |
2058 | } | |
2059 | ||
1da177e4 LT |
2060 | /* Hook functions begin here. */ |
2061 | ||
79af7307 SS |
2062 | static int selinux_binder_set_context_mgr(struct task_struct *mgr) |
2063 | { | |
2064 | u32 mysid = current_sid(); | |
2065 | u32 mgrsid = task_sid(mgr); | |
2066 | ||
6b6bc620 SS |
2067 | return avc_has_perm(&selinux_state, |
2068 | mysid, mgrsid, SECCLASS_BINDER, | |
79af7307 SS |
2069 | BINDER__SET_CONTEXT_MGR, NULL); |
2070 | } | |
2071 | ||
2072 | static int selinux_binder_transaction(struct task_struct *from, | |
2073 | struct task_struct *to) | |
2074 | { | |
2075 | u32 mysid = current_sid(); | |
2076 | u32 fromsid = task_sid(from); | |
2077 | u32 tosid = task_sid(to); | |
2078 | int rc; | |
2079 | ||
2080 | if (mysid != fromsid) { | |
6b6bc620 SS |
2081 | rc = avc_has_perm(&selinux_state, |
2082 | mysid, fromsid, SECCLASS_BINDER, | |
79af7307 SS |
2083 | BINDER__IMPERSONATE, NULL); |
2084 | if (rc) | |
2085 | return rc; | |
2086 | } | |
2087 | ||
6b6bc620 SS |
2088 | return avc_has_perm(&selinux_state, |
2089 | fromsid, tosid, SECCLASS_BINDER, BINDER__CALL, | |
79af7307 SS |
2090 | NULL); |
2091 | } | |
2092 | ||
2093 | static int selinux_binder_transfer_binder(struct task_struct *from, | |
2094 | struct task_struct *to) | |
2095 | { | |
2096 | u32 fromsid = task_sid(from); | |
2097 | u32 tosid = task_sid(to); | |
2098 | ||
6b6bc620 SS |
2099 | return avc_has_perm(&selinux_state, |
2100 | fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER, | |
79af7307 SS |
2101 | NULL); |
2102 | } | |
2103 | ||
2104 | static int selinux_binder_transfer_file(struct task_struct *from, | |
2105 | struct task_struct *to, | |
2106 | struct file *file) | |
2107 | { | |
2108 | u32 sid = task_sid(to); | |
2109 | struct file_security_struct *fsec = file->f_security; | |
83da53c5 | 2110 | struct dentry *dentry = file->f_path.dentry; |
20cdef8d | 2111 | struct inode_security_struct *isec; |
79af7307 SS |
2112 | struct common_audit_data ad; |
2113 | int rc; | |
2114 | ||
2115 | ad.type = LSM_AUDIT_DATA_PATH; | |
2116 | ad.u.path = file->f_path; | |
2117 | ||
2118 | if (sid != fsec->sid) { | |
6b6bc620 SS |
2119 | rc = avc_has_perm(&selinux_state, |
2120 | sid, fsec->sid, | |
79af7307 SS |
2121 | SECCLASS_FD, |
2122 | FD__USE, | |
2123 | &ad); | |
2124 | if (rc) | |
2125 | return rc; | |
2126 | } | |
2127 | ||
f66e448c CF |
2128 | #ifdef CONFIG_BPF_SYSCALL |
2129 | rc = bpf_fd_pass(file, sid); | |
2130 | if (rc) | |
2131 | return rc; | |
2132 | #endif | |
2133 | ||
83da53c5 | 2134 | if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) |
79af7307 SS |
2135 | return 0; |
2136 | ||
20cdef8d | 2137 | isec = backing_inode_security(dentry); |
6b6bc620 SS |
2138 | return avc_has_perm(&selinux_state, |
2139 | sid, isec->sid, isec->sclass, file_to_av(file), | |
79af7307 SS |
2140 | &ad); |
2141 | } | |
2142 | ||
9e48858f | 2143 | static int selinux_ptrace_access_check(struct task_struct *child, |
5cd9c58f | 2144 | unsigned int mode) |
1da177e4 | 2145 | { |
be0554c9 SS |
2146 | u32 sid = current_sid(); |
2147 | u32 csid = task_sid(child); | |
2148 | ||
2149 | if (mode & PTRACE_MODE_READ) | |
6b6bc620 SS |
2150 | return avc_has_perm(&selinux_state, |
2151 | sid, csid, SECCLASS_FILE, FILE__READ, NULL); | |
006ebb40 | 2152 | |
6b6bc620 SS |
2153 | return avc_has_perm(&selinux_state, |
2154 | sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL); | |
5cd9c58f DH |
2155 | } |
2156 | ||
2157 | static int selinux_ptrace_traceme(struct task_struct *parent) | |
2158 | { | |
6b6bc620 SS |
2159 | return avc_has_perm(&selinux_state, |
2160 | task_sid(parent), current_sid(), SECCLASS_PROCESS, | |
be0554c9 | 2161 | PROCESS__PTRACE, NULL); |
1da177e4 LT |
2162 | } |
2163 | ||
2164 | static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, | |
828dfe1d | 2165 | kernel_cap_t *inheritable, kernel_cap_t *permitted) |
1da177e4 | 2166 | { |
6b6bc620 SS |
2167 | return avc_has_perm(&selinux_state, |
2168 | current_sid(), task_sid(target), SECCLASS_PROCESS, | |
be0554c9 | 2169 | PROCESS__GETCAP, NULL); |
1da177e4 LT |
2170 | } |
2171 | ||
d84f4f99 DH |
2172 | static int selinux_capset(struct cred *new, const struct cred *old, |
2173 | const kernel_cap_t *effective, | |
2174 | const kernel_cap_t *inheritable, | |
2175 | const kernel_cap_t *permitted) | |
1da177e4 | 2176 | { |
6b6bc620 SS |
2177 | return avc_has_perm(&selinux_state, |
2178 | cred_sid(old), cred_sid(new), SECCLASS_PROCESS, | |
be0554c9 | 2179 | PROCESS__SETCAP, NULL); |
1da177e4 LT |
2180 | } |
2181 | ||
5626d3e8 JM |
2182 | /* |
2183 | * (This comment used to live with the selinux_task_setuid hook, | |
2184 | * which was removed). | |
2185 | * | |
2186 | * Since setuid only affects the current process, and since the SELinux | |
2187 | * controls are not based on the Linux identity attributes, SELinux does not | |
2188 | * need to control this operation. However, SELinux does control the use of | |
2189 | * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. | |
2190 | */ | |
2191 | ||
6a9de491 EP |
2192 | static int selinux_capable(const struct cred *cred, struct user_namespace *ns, |
2193 | int cap, int audit) | |
1da177e4 | 2194 | { |
8e4ff6f2 | 2195 | return cred_has_capability(cred, cap, audit, ns == &init_user_ns); |
1da177e4 LT |
2196 | } |
2197 | ||
1da177e4 LT |
2198 | static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) |
2199 | { | |
88e67f3b | 2200 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2201 | int rc = 0; |
2202 | ||
2203 | if (!sb) | |
2204 | return 0; | |
2205 | ||
2206 | switch (cmds) { | |
828dfe1d EP |
2207 | case Q_SYNC: |
2208 | case Q_QUOTAON: | |
2209 | case Q_QUOTAOFF: | |
2210 | case Q_SETINFO: | |
2211 | case Q_SETQUOTA: | |
88e67f3b | 2212 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); |
828dfe1d EP |
2213 | break; |
2214 | case Q_GETFMT: | |
2215 | case Q_GETINFO: | |
2216 | case Q_GETQUOTA: | |
88e67f3b | 2217 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); |
828dfe1d EP |
2218 | break; |
2219 | default: | |
2220 | rc = 0; /* let the kernel handle invalid cmds */ | |
2221 | break; | |
1da177e4 LT |
2222 | } |
2223 | return rc; | |
2224 | } | |
2225 | ||
2226 | static int selinux_quota_on(struct dentry *dentry) | |
2227 | { | |
88e67f3b DH |
2228 | const struct cred *cred = current_cred(); |
2229 | ||
2875fa00 | 2230 | return dentry_has_perm(cred, dentry, FILE__QUOTAON); |
1da177e4 LT |
2231 | } |
2232 | ||
12b3052c | 2233 | static int selinux_syslog(int type) |
1da177e4 | 2234 | { |
1da177e4 | 2235 | switch (type) { |
d78ca3cd KC |
2236 | case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ |
2237 | case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ | |
6b6bc620 SS |
2238 | return avc_has_perm(&selinux_state, |
2239 | current_sid(), SECINITSID_KERNEL, | |
be0554c9 | 2240 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL); |
d78ca3cd KC |
2241 | case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ |
2242 | case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ | |
2243 | /* Set level of messages printed to console */ | |
2244 | case SYSLOG_ACTION_CONSOLE_LEVEL: | |
6b6bc620 SS |
2245 | return avc_has_perm(&selinux_state, |
2246 | current_sid(), SECINITSID_KERNEL, | |
be0554c9 SS |
2247 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, |
2248 | NULL); | |
1da177e4 | 2249 | } |
be0554c9 | 2250 | /* All other syslog types */ |
6b6bc620 SS |
2251 | return avc_has_perm(&selinux_state, |
2252 | current_sid(), SECINITSID_KERNEL, | |
be0554c9 | 2253 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL); |
1da177e4 LT |
2254 | } |
2255 | ||
2256 | /* | |
2257 | * Check that a process has enough memory to allocate a new virtual | |
2258 | * mapping. 0 means there is enough memory for the allocation to | |
2259 | * succeed and -ENOMEM implies there is not. | |
2260 | * | |
1da177e4 LT |
2261 | * Do not audit the selinux permission check, as this is applied to all |
2262 | * processes that allocate mappings. | |
2263 | */ | |
34b4e4aa | 2264 | static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
2265 | { |
2266 | int rc, cap_sys_admin = 0; | |
1da177e4 | 2267 | |
b1d9e6b0 | 2268 | rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN, |
8e4ff6f2 | 2269 | SECURITY_CAP_NOAUDIT, true); |
1da177e4 LT |
2270 | if (rc == 0) |
2271 | cap_sys_admin = 1; | |
2272 | ||
b1d9e6b0 | 2273 | return cap_sys_admin; |
1da177e4 LT |
2274 | } |
2275 | ||
2276 | /* binprm security operations */ | |
2277 | ||
be0554c9 | 2278 | static u32 ptrace_parent_sid(void) |
0c6181cb PM |
2279 | { |
2280 | u32 sid = 0; | |
2281 | struct task_struct *tracer; | |
2282 | ||
2283 | rcu_read_lock(); | |
be0554c9 | 2284 | tracer = ptrace_parent(current); |
0c6181cb PM |
2285 | if (tracer) |
2286 | sid = task_sid(tracer); | |
2287 | rcu_read_unlock(); | |
2288 | ||
2289 | return sid; | |
2290 | } | |
2291 | ||
7b0d0b40 SS |
2292 | static int check_nnp_nosuid(const struct linux_binprm *bprm, |
2293 | const struct task_security_struct *old_tsec, | |
2294 | const struct task_security_struct *new_tsec) | |
2295 | { | |
2296 | int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); | |
380cf5ba | 2297 | int nosuid = !mnt_may_suid(bprm->file->f_path.mnt); |
7b0d0b40 | 2298 | int rc; |
af63f419 | 2299 | u32 av; |
7b0d0b40 SS |
2300 | |
2301 | if (!nnp && !nosuid) | |
2302 | return 0; /* neither NNP nor nosuid */ | |
2303 | ||
2304 | if (new_tsec->sid == old_tsec->sid) | |
2305 | return 0; /* No change in credentials */ | |
2306 | ||
2307 | /* | |
af63f419 SS |
2308 | * If the policy enables the nnp_nosuid_transition policy capability, |
2309 | * then we permit transitions under NNP or nosuid if the | |
2310 | * policy allows the corresponding permission between | |
2311 | * the old and new contexts. | |
7b0d0b40 | 2312 | */ |
aa8e712c | 2313 | if (selinux_policycap_nnp_nosuid_transition()) { |
af63f419 | 2314 | av = 0; |
7b0d0b40 | 2315 | if (nnp) |
af63f419 SS |
2316 | av |= PROCESS2__NNP_TRANSITION; |
2317 | if (nosuid) | |
2318 | av |= PROCESS2__NOSUID_TRANSITION; | |
6b6bc620 SS |
2319 | rc = avc_has_perm(&selinux_state, |
2320 | old_tsec->sid, new_tsec->sid, | |
af63f419 SS |
2321 | SECCLASS_PROCESS2, av, NULL); |
2322 | if (!rc) | |
2323 | return 0; | |
7b0d0b40 | 2324 | } |
af63f419 SS |
2325 | |
2326 | /* | |
2327 | * We also permit NNP or nosuid transitions to bounded SIDs, | |
2328 | * i.e. SIDs that are guaranteed to only be allowed a subset | |
2329 | * of the permissions of the current SID. | |
2330 | */ | |
aa8e712c SS |
2331 | rc = security_bounded_transition(&selinux_state, old_tsec->sid, |
2332 | new_tsec->sid); | |
af63f419 SS |
2333 | if (!rc) |
2334 | return 0; | |
2335 | ||
2336 | /* | |
2337 | * On failure, preserve the errno values for NNP vs nosuid. | |
2338 | * NNP: Operation not permitted for caller. | |
2339 | * nosuid: Permission denied to file. | |
2340 | */ | |
2341 | if (nnp) | |
2342 | return -EPERM; | |
2343 | return -EACCES; | |
7b0d0b40 SS |
2344 | } |
2345 | ||
a6f76f23 | 2346 | static int selinux_bprm_set_creds(struct linux_binprm *bprm) |
1da177e4 | 2347 | { |
a6f76f23 DH |
2348 | const struct task_security_struct *old_tsec; |
2349 | struct task_security_struct *new_tsec; | |
1da177e4 | 2350 | struct inode_security_struct *isec; |
2bf49690 | 2351 | struct common_audit_data ad; |
496ad9aa | 2352 | struct inode *inode = file_inode(bprm->file); |
1da177e4 LT |
2353 | int rc; |
2354 | ||
a6f76f23 DH |
2355 | /* SELinux context only depends on initial program or script and not |
2356 | * the script interpreter */ | |
ddb4a144 | 2357 | if (bprm->called_set_creds) |
1da177e4 LT |
2358 | return 0; |
2359 | ||
a6f76f23 DH |
2360 | old_tsec = current_security(); |
2361 | new_tsec = bprm->cred->security; | |
83da53c5 | 2362 | isec = inode_security(inode); |
1da177e4 LT |
2363 | |
2364 | /* Default to the current task SID. */ | |
a6f76f23 DH |
2365 | new_tsec->sid = old_tsec->sid; |
2366 | new_tsec->osid = old_tsec->sid; | |
1da177e4 | 2367 | |
28eba5bf | 2368 | /* Reset fs, key, and sock SIDs on execve. */ |
a6f76f23 DH |
2369 | new_tsec->create_sid = 0; |
2370 | new_tsec->keycreate_sid = 0; | |
2371 | new_tsec->sockcreate_sid = 0; | |
1da177e4 | 2372 | |
a6f76f23 DH |
2373 | if (old_tsec->exec_sid) { |
2374 | new_tsec->sid = old_tsec->exec_sid; | |
1da177e4 | 2375 | /* Reset exec SID on execve. */ |
a6f76f23 | 2376 | new_tsec->exec_sid = 0; |
259e5e6c | 2377 | |
7b0d0b40 SS |
2378 | /* Fail on NNP or nosuid if not an allowed transition. */ |
2379 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2380 | if (rc) | |
2381 | return rc; | |
1da177e4 LT |
2382 | } else { |
2383 | /* Check for a default transition on this program. */ | |
aa8e712c SS |
2384 | rc = security_transition_sid(&selinux_state, old_tsec->sid, |
2385 | isec->sid, SECCLASS_PROCESS, NULL, | |
652bb9b0 | 2386 | &new_tsec->sid); |
1da177e4 LT |
2387 | if (rc) |
2388 | return rc; | |
7b0d0b40 SS |
2389 | |
2390 | /* | |
2391 | * Fallback to old SID on NNP or nosuid if not an allowed | |
2392 | * transition. | |
2393 | */ | |
2394 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2395 | if (rc) | |
2396 | new_tsec->sid = old_tsec->sid; | |
1da177e4 LT |
2397 | } |
2398 | ||
43af5de7 VG |
2399 | ad.type = LSM_AUDIT_DATA_FILE; |
2400 | ad.u.file = bprm->file; | |
1da177e4 | 2401 | |
a6f76f23 | 2402 | if (new_tsec->sid == old_tsec->sid) { |
6b6bc620 SS |
2403 | rc = avc_has_perm(&selinux_state, |
2404 | old_tsec->sid, isec->sid, | |
1da177e4 LT |
2405 | SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); |
2406 | if (rc) | |
2407 | return rc; | |
2408 | } else { | |
2409 | /* Check permissions for the transition. */ | |
6b6bc620 SS |
2410 | rc = avc_has_perm(&selinux_state, |
2411 | old_tsec->sid, new_tsec->sid, | |
1da177e4 LT |
2412 | SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); |
2413 | if (rc) | |
2414 | return rc; | |
2415 | ||
6b6bc620 SS |
2416 | rc = avc_has_perm(&selinux_state, |
2417 | new_tsec->sid, isec->sid, | |
1da177e4 LT |
2418 | SECCLASS_FILE, FILE__ENTRYPOINT, &ad); |
2419 | if (rc) | |
2420 | return rc; | |
2421 | ||
a6f76f23 DH |
2422 | /* Check for shared state */ |
2423 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
6b6bc620 SS |
2424 | rc = avc_has_perm(&selinux_state, |
2425 | old_tsec->sid, new_tsec->sid, | |
a6f76f23 DH |
2426 | SECCLASS_PROCESS, PROCESS__SHARE, |
2427 | NULL); | |
2428 | if (rc) | |
2429 | return -EPERM; | |
2430 | } | |
2431 | ||
2432 | /* Make sure that anyone attempting to ptrace over a task that | |
2433 | * changes its SID has the appropriate permit */ | |
9227dd2a | 2434 | if (bprm->unsafe & LSM_UNSAFE_PTRACE) { |
be0554c9 | 2435 | u32 ptsid = ptrace_parent_sid(); |
a6f76f23 | 2436 | if (ptsid != 0) { |
6b6bc620 SS |
2437 | rc = avc_has_perm(&selinux_state, |
2438 | ptsid, new_tsec->sid, | |
a6f76f23 DH |
2439 | SECCLASS_PROCESS, |
2440 | PROCESS__PTRACE, NULL); | |
2441 | if (rc) | |
2442 | return -EPERM; | |
2443 | } | |
2444 | } | |
1da177e4 | 2445 | |
a6f76f23 DH |
2446 | /* Clear any possibly unsafe personality bits on exec: */ |
2447 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
275bb41e | 2448 | |
1da177e4 LT |
2449 | /* Enable secure mode for SIDs transitions unless |
2450 | the noatsecure permission is granted between | |
2451 | the two SIDs, i.e. ahp returns 0. */ | |
6b6bc620 SS |
2452 | rc = avc_has_perm(&selinux_state, |
2453 | old_tsec->sid, new_tsec->sid, | |
62874c3a KC |
2454 | SECCLASS_PROCESS, PROCESS__NOATSECURE, |
2455 | NULL); | |
2456 | bprm->secureexec |= !!rc; | |
1da177e4 LT |
2457 | } |
2458 | ||
62874c3a | 2459 | return 0; |
1da177e4 LT |
2460 | } |
2461 | ||
c3c073f8 AV |
2462 | static int match_file(const void *p, struct file *file, unsigned fd) |
2463 | { | |
2464 | return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; | |
2465 | } | |
2466 | ||
1da177e4 | 2467 | /* Derived from fs/exec.c:flush_old_files. */ |
745ca247 DH |
2468 | static inline void flush_unauthorized_files(const struct cred *cred, |
2469 | struct files_struct *files) | |
1da177e4 | 2470 | { |
1da177e4 | 2471 | struct file *file, *devnull = NULL; |
b20c8122 | 2472 | struct tty_struct *tty; |
24ec839c | 2473 | int drop_tty = 0; |
c3c073f8 | 2474 | unsigned n; |
1da177e4 | 2475 | |
24ec839c | 2476 | tty = get_current_tty(); |
1da177e4 | 2477 | if (tty) { |
4a510969 | 2478 | spin_lock(&tty->files_lock); |
37dd0bd0 | 2479 | if (!list_empty(&tty->tty_files)) { |
d996b62a | 2480 | struct tty_file_private *file_priv; |
37dd0bd0 | 2481 | |
1da177e4 | 2482 | /* Revalidate access to controlling tty. |
13f8e981 DH |
2483 | Use file_path_has_perm on the tty path directly |
2484 | rather than using file_has_perm, as this particular | |
2485 | open file may belong to another process and we are | |
2486 | only interested in the inode-based check here. */ | |
d996b62a NP |
2487 | file_priv = list_first_entry(&tty->tty_files, |
2488 | struct tty_file_private, list); | |
2489 | file = file_priv->file; | |
13f8e981 | 2490 | if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE)) |
24ec839c | 2491 | drop_tty = 1; |
1da177e4 | 2492 | } |
4a510969 | 2493 | spin_unlock(&tty->files_lock); |
452a00d2 | 2494 | tty_kref_put(tty); |
1da177e4 | 2495 | } |
98a27ba4 EB |
2496 | /* Reset controlling tty. */ |
2497 | if (drop_tty) | |
2498 | no_tty(); | |
1da177e4 LT |
2499 | |
2500 | /* Revalidate access to inherited open files. */ | |
c3c073f8 AV |
2501 | n = iterate_fd(files, 0, match_file, cred); |
2502 | if (!n) /* none found? */ | |
2503 | return; | |
1da177e4 | 2504 | |
c3c073f8 | 2505 | devnull = dentry_open(&selinux_null, O_RDWR, cred); |
45525b26 AV |
2506 | if (IS_ERR(devnull)) |
2507 | devnull = NULL; | |
2508 | /* replace all the matching ones with this */ | |
2509 | do { | |
2510 | replace_fd(n - 1, devnull, 0); | |
2511 | } while ((n = iterate_fd(files, n, match_file, cred)) != 0); | |
2512 | if (devnull) | |
c3c073f8 | 2513 | fput(devnull); |
1da177e4 LT |
2514 | } |
2515 | ||
a6f76f23 DH |
2516 | /* |
2517 | * Prepare a process for imminent new credential changes due to exec | |
2518 | */ | |
2519 | static void selinux_bprm_committing_creds(struct linux_binprm *bprm) | |
1da177e4 | 2520 | { |
a6f76f23 DH |
2521 | struct task_security_struct *new_tsec; |
2522 | struct rlimit *rlim, *initrlim; | |
2523 | int rc, i; | |
d84f4f99 | 2524 | |
a6f76f23 DH |
2525 | new_tsec = bprm->cred->security; |
2526 | if (new_tsec->sid == new_tsec->osid) | |
2527 | return; | |
1da177e4 | 2528 | |
a6f76f23 DH |
2529 | /* Close files for which the new task SID is not authorized. */ |
2530 | flush_unauthorized_files(bprm->cred, current->files); | |
0356357c | 2531 | |
a6f76f23 DH |
2532 | /* Always clear parent death signal on SID transitions. */ |
2533 | current->pdeath_signal = 0; | |
0356357c | 2534 | |
a6f76f23 DH |
2535 | /* Check whether the new SID can inherit resource limits from the old |
2536 | * SID. If not, reset all soft limits to the lower of the current | |
2537 | * task's hard limit and the init task's soft limit. | |
2538 | * | |
2539 | * Note that the setting of hard limits (even to lower them) can be | |
2540 | * controlled by the setrlimit check. The inclusion of the init task's | |
2541 | * soft limit into the computation is to avoid resetting soft limits | |
2542 | * higher than the default soft limit for cases where the default is | |
2543 | * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. | |
2544 | */ | |
6b6bc620 SS |
2545 | rc = avc_has_perm(&selinux_state, |
2546 | new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, | |
a6f76f23 DH |
2547 | PROCESS__RLIMITINH, NULL); |
2548 | if (rc) { | |
eb2d55a3 ON |
2549 | /* protect against do_prlimit() */ |
2550 | task_lock(current); | |
a6f76f23 DH |
2551 | for (i = 0; i < RLIM_NLIMITS; i++) { |
2552 | rlim = current->signal->rlim + i; | |
2553 | initrlim = init_task.signal->rlim + i; | |
2554 | rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); | |
1da177e4 | 2555 | } |
eb2d55a3 | 2556 | task_unlock(current); |
baa73d9e NP |
2557 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) |
2558 | update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); | |
1da177e4 LT |
2559 | } |
2560 | } | |
2561 | ||
2562 | /* | |
a6f76f23 DH |
2563 | * Clean up the process immediately after the installation of new credentials |
2564 | * due to exec | |
1da177e4 | 2565 | */ |
a6f76f23 | 2566 | static void selinux_bprm_committed_creds(struct linux_binprm *bprm) |
1da177e4 | 2567 | { |
a6f76f23 | 2568 | const struct task_security_struct *tsec = current_security(); |
1da177e4 | 2569 | struct itimerval itimer; |
a6f76f23 | 2570 | u32 osid, sid; |
1da177e4 LT |
2571 | int rc, i; |
2572 | ||
a6f76f23 DH |
2573 | osid = tsec->osid; |
2574 | sid = tsec->sid; | |
2575 | ||
2576 | if (sid == osid) | |
1da177e4 LT |
2577 | return; |
2578 | ||
a6f76f23 DH |
2579 | /* Check whether the new SID can inherit signal state from the old SID. |
2580 | * If not, clear itimers to avoid subsequent signal generation and | |
2581 | * flush and unblock signals. | |
2582 | * | |
2583 | * This must occur _after_ the task SID has been updated so that any | |
2584 | * kill done after the flush will be checked against the new SID. | |
2585 | */ | |
6b6bc620 SS |
2586 | rc = avc_has_perm(&selinux_state, |
2587 | osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); | |
1da177e4 | 2588 | if (rc) { |
baa73d9e NP |
2589 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) { |
2590 | memset(&itimer, 0, sizeof itimer); | |
2591 | for (i = 0; i < 3; i++) | |
2592 | do_setitimer(i, &itimer, NULL); | |
2593 | } | |
1da177e4 | 2594 | spin_lock_irq(¤t->sighand->siglock); |
9e7c8f8c ON |
2595 | if (!fatal_signal_pending(current)) { |
2596 | flush_sigqueue(¤t->pending); | |
2597 | flush_sigqueue(¤t->signal->shared_pending); | |
3bcac026 DH |
2598 | flush_signal_handlers(current, 1); |
2599 | sigemptyset(¤t->blocked); | |
9e7c8f8c | 2600 | recalc_sigpending(); |
3bcac026 | 2601 | } |
1da177e4 LT |
2602 | spin_unlock_irq(¤t->sighand->siglock); |
2603 | } | |
2604 | ||
a6f76f23 DH |
2605 | /* Wake up the parent if it is waiting so that it can recheck |
2606 | * wait permission to the new task SID. */ | |
ecd6de3c | 2607 | read_lock(&tasklist_lock); |
0b7570e7 | 2608 | __wake_up_parent(current, current->real_parent); |
ecd6de3c | 2609 | read_unlock(&tasklist_lock); |
1da177e4 LT |
2610 | } |
2611 | ||
2612 | /* superblock security operations */ | |
2613 | ||
2614 | static int selinux_sb_alloc_security(struct super_block *sb) | |
2615 | { | |
2616 | return superblock_alloc_security(sb); | |
2617 | } | |
2618 | ||
2619 | static void selinux_sb_free_security(struct super_block *sb) | |
2620 | { | |
2621 | superblock_free_security(sb); | |
2622 | } | |
2623 | ||
99dbbb59 | 2624 | static inline int opt_len(const char *s) |
1da177e4 | 2625 | { |
99dbbb59 AV |
2626 | bool open_quote = false; |
2627 | int len; | |
2628 | char c; | |
1da177e4 | 2629 | |
99dbbb59 AV |
2630 | for (len = 0; (c = s[len]) != '\0'; len++) { |
2631 | if (c == '"') | |
2632 | open_quote = !open_quote; | |
2633 | if (c == ',' && !open_quote) | |
2634 | break; | |
3528a953 | 2635 | } |
99dbbb59 | 2636 | return len; |
3528a953 CO |
2637 | } |
2638 | ||
99dbbb59 | 2639 | static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts) |
1da177e4 | 2640 | { |
99dbbb59 AV |
2641 | char *from = options; |
2642 | char *to = options; | |
2643 | bool first = true; | |
1da177e4 | 2644 | |
99dbbb59 AV |
2645 | while (1) { |
2646 | int len = opt_len(from); | |
2647 | int token, rc; | |
2648 | char *arg = NULL; | |
1da177e4 | 2649 | |
99dbbb59 | 2650 | token = match_opt_prefix(from, len, &arg); |
1da177e4 | 2651 | |
99dbbb59 AV |
2652 | if (token != Opt_error) { |
2653 | char *p, *q; | |
1da177e4 | 2654 | |
99dbbb59 AV |
2655 | /* strip quotes */ |
2656 | if (arg) { | |
2657 | for (p = q = arg; p < from + len; p++) { | |
2658 | char c = *p; | |
2659 | if (c != '"') | |
2660 | *q++ = c; | |
2661 | } | |
2662 | arg = kmemdup_nul(arg, q - arg, GFP_KERNEL); | |
2663 | } | |
2664 | rc = selinux_add_opt(token, arg, mnt_opts); | |
2665 | if (unlikely(rc)) { | |
2666 | kfree(arg); | |
2667 | if (*mnt_opts) { | |
2668 | selinux_free_mnt_opts(*mnt_opts); | |
2669 | *mnt_opts = NULL; | |
2670 | } | |
2671 | return rc; | |
2672 | } | |
2673 | } else { | |
2674 | if (!first) { // copy with preceding comma | |
2675 | from--; | |
2676 | len++; | |
2677 | } | |
2678 | if (to != from) | |
2679 | memmove(to, from, len); | |
2680 | to += len; | |
2681 | first = false; | |
1da177e4 | 2682 | } |
99dbbb59 AV |
2683 | if (!from[len]) |
2684 | break; | |
2685 | from += len + 1; | |
2686 | } | |
2687 | *to = '\0'; | |
2688 | return 0; | |
1da177e4 LT |
2689 | } |
2690 | ||
204cc0cc | 2691 | static int selinux_sb_remount(struct super_block *sb, void *mnt_opts) |
026eb167 | 2692 | { |
bd323655 | 2693 | struct selinux_mnt_opts *opts = mnt_opts; |
026eb167 | 2694 | struct superblock_security_struct *sbsec = sb->s_security; |
bd323655 AV |
2695 | u32 sid; |
2696 | int rc; | |
026eb167 EP |
2697 | |
2698 | if (!(sbsec->flags & SE_SBINITIALIZED)) | |
2699 | return 0; | |
2700 | ||
204cc0cc | 2701 | if (!opts) |
026eb167 EP |
2702 | return 0; |
2703 | ||
bd323655 AV |
2704 | if (opts->fscontext) { |
2705 | rc = parse_sid(sb, opts->fscontext, &sid); | |
2706 | if (rc) | |
c039bc3c | 2707 | return rc; |
bd323655 AV |
2708 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) |
2709 | goto out_bad_option; | |
026eb167 | 2710 | } |
bd323655 AV |
2711 | if (opts->context) { |
2712 | rc = parse_sid(sb, opts->context, &sid); | |
2713 | if (rc) | |
2714 | return rc; | |
2715 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) | |
2716 | goto out_bad_option; | |
2717 | } | |
2718 | if (opts->rootcontext) { | |
2719 | struct inode_security_struct *root_isec; | |
2720 | root_isec = backing_inode_security(sb->s_root); | |
2721 | rc = parse_sid(sb, opts->rootcontext, &sid); | |
2722 | if (rc) | |
2723 | return rc; | |
2724 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) | |
2725 | goto out_bad_option; | |
2726 | } | |
2727 | if (opts->defcontext) { | |
2728 | rc = parse_sid(sb, opts->defcontext, &sid); | |
2729 | if (rc) | |
2730 | return rc; | |
2731 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) | |
2732 | goto out_bad_option; | |
026eb167 | 2733 | } |
c039bc3c | 2734 | return 0; |
026eb167 | 2735 | |
026eb167 | 2736 | out_bad_option: |
c103a91e | 2737 | pr_warn("SELinux: unable to change security options " |
29b1deb2 LT |
2738 | "during remount (dev %s, type=%s)\n", sb->s_id, |
2739 | sb->s_type->name); | |
c039bc3c | 2740 | return -EINVAL; |
026eb167 EP |
2741 | } |
2742 | ||
a10d7c22 | 2743 | static int selinux_sb_kern_mount(struct super_block *sb) |
1da177e4 | 2744 | { |
88e67f3b | 2745 | const struct cred *cred = current_cred(); |
2bf49690 | 2746 | struct common_audit_data ad; |
74192246 | 2747 | |
50c205f5 | 2748 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2749 | ad.u.dentry = sb->s_root; |
88e67f3b | 2750 | return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); |
1da177e4 LT |
2751 | } |
2752 | ||
726c3342 | 2753 | static int selinux_sb_statfs(struct dentry *dentry) |
1da177e4 | 2754 | { |
88e67f3b | 2755 | const struct cred *cred = current_cred(); |
2bf49690 | 2756 | struct common_audit_data ad; |
1da177e4 | 2757 | |
50c205f5 | 2758 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2759 | ad.u.dentry = dentry->d_sb->s_root; |
88e67f3b | 2760 | return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); |
1da177e4 LT |
2761 | } |
2762 | ||
808d4e3c | 2763 | static int selinux_mount(const char *dev_name, |
8a04c43b | 2764 | const struct path *path, |
808d4e3c | 2765 | const char *type, |
828dfe1d EP |
2766 | unsigned long flags, |
2767 | void *data) | |
1da177e4 | 2768 | { |
88e67f3b | 2769 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2770 | |
2771 | if (flags & MS_REMOUNT) | |
d8c9584e | 2772 | return superblock_has_perm(cred, path->dentry->d_sb, |
828dfe1d | 2773 | FILESYSTEM__REMOUNT, NULL); |
1da177e4 | 2774 | else |
2875fa00 | 2775 | return path_has_perm(cred, path, FILE__MOUNTON); |
1da177e4 LT |
2776 | } |
2777 | ||
2778 | static int selinux_umount(struct vfsmount *mnt, int flags) | |
2779 | { | |
88e67f3b | 2780 | const struct cred *cred = current_cred(); |
1da177e4 | 2781 | |
88e67f3b | 2782 | return superblock_has_perm(cred, mnt->mnt_sb, |
828dfe1d | 2783 | FILESYSTEM__UNMOUNT, NULL); |
1da177e4 LT |
2784 | } |
2785 | ||
2786 | /* inode security operations */ | |
2787 | ||
2788 | static int selinux_inode_alloc_security(struct inode *inode) | |
2789 | { | |
2790 | return inode_alloc_security(inode); | |
2791 | } | |
2792 | ||
2793 | static void selinux_inode_free_security(struct inode *inode) | |
2794 | { | |
2795 | inode_free_security(inode); | |
2796 | } | |
2797 | ||
d47be3df | 2798 | static int selinux_dentry_init_security(struct dentry *dentry, int mode, |
4f3ccd76 | 2799 | const struct qstr *name, void **ctx, |
d47be3df DQ |
2800 | u32 *ctxlen) |
2801 | { | |
d47be3df DQ |
2802 | u32 newsid; |
2803 | int rc; | |
2804 | ||
c957f6df VG |
2805 | rc = selinux_determine_inode_label(current_security(), |
2806 | d_inode(dentry->d_parent), name, | |
c3c188b2 DH |
2807 | inode_mode_to_security_class(mode), |
2808 | &newsid); | |
2809 | if (rc) | |
2810 | return rc; | |
d47be3df | 2811 | |
aa8e712c SS |
2812 | return security_sid_to_context(&selinux_state, newsid, (char **)ctx, |
2813 | ctxlen); | |
d47be3df DQ |
2814 | } |
2815 | ||
a518b0a5 VG |
2816 | static int selinux_dentry_create_files_as(struct dentry *dentry, int mode, |
2817 | struct qstr *name, | |
2818 | const struct cred *old, | |
2819 | struct cred *new) | |
2820 | { | |
2821 | u32 newsid; | |
2822 | int rc; | |
2823 | struct task_security_struct *tsec; | |
2824 | ||
2825 | rc = selinux_determine_inode_label(old->security, | |
2826 | d_inode(dentry->d_parent), name, | |
2827 | inode_mode_to_security_class(mode), | |
2828 | &newsid); | |
2829 | if (rc) | |
2830 | return rc; | |
2831 | ||
2832 | tsec = new->security; | |
2833 | tsec->create_sid = newsid; | |
2834 | return 0; | |
2835 | } | |
2836 | ||
5e41ff9e | 2837 | static int selinux_inode_init_security(struct inode *inode, struct inode *dir, |
9548906b TH |
2838 | const struct qstr *qstr, |
2839 | const char **name, | |
2a7dba39 | 2840 | void **value, size_t *len) |
5e41ff9e | 2841 | { |
5fb49870 | 2842 | const struct task_security_struct *tsec = current_security(); |
5e41ff9e | 2843 | struct superblock_security_struct *sbsec; |
c0d4f464 | 2844 | u32 newsid, clen; |
5e41ff9e | 2845 | int rc; |
9548906b | 2846 | char *context; |
5e41ff9e | 2847 | |
5e41ff9e | 2848 | sbsec = dir->i_sb->s_security; |
5e41ff9e | 2849 | |
275bb41e DH |
2850 | newsid = tsec->create_sid; |
2851 | ||
c957f6df | 2852 | rc = selinux_determine_inode_label(current_security(), |
c3c188b2 DH |
2853 | dir, qstr, |
2854 | inode_mode_to_security_class(inode->i_mode), | |
2855 | &newsid); | |
2856 | if (rc) | |
2857 | return rc; | |
5e41ff9e | 2858 | |
296fddf7 | 2859 | /* Possibly defer initialization to selinux_complete_init. */ |
0d90a7ec | 2860 | if (sbsec->flags & SE_SBINITIALIZED) { |
296fddf7 EP |
2861 | struct inode_security_struct *isec = inode->i_security; |
2862 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
2863 | isec->sid = newsid; | |
6f3be9f5 | 2864 | isec->initialized = LABEL_INITIALIZED; |
296fddf7 | 2865 | } |
5e41ff9e | 2866 | |
aa8e712c | 2867 | if (!selinux_state.initialized || !(sbsec->flags & SBLABEL_MNT)) |
25a74f3b SS |
2868 | return -EOPNOTSUPP; |
2869 | ||
9548906b TH |
2870 | if (name) |
2871 | *name = XATTR_SELINUX_SUFFIX; | |
5e41ff9e | 2872 | |
570bc1c2 | 2873 | if (value && len) { |
aa8e712c SS |
2874 | rc = security_sid_to_context_force(&selinux_state, newsid, |
2875 | &context, &clen); | |
9548906b | 2876 | if (rc) |
570bc1c2 | 2877 | return rc; |
570bc1c2 SS |
2878 | *value = context; |
2879 | *len = clen; | |
5e41ff9e | 2880 | } |
5e41ff9e | 2881 | |
5e41ff9e SS |
2882 | return 0; |
2883 | } | |
2884 | ||
4acdaf27 | 2885 | static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
2886 | { |
2887 | return may_create(dir, dentry, SECCLASS_FILE); | |
2888 | } | |
2889 | ||
1da177e4 LT |
2890 | static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) |
2891 | { | |
1da177e4 LT |
2892 | return may_link(dir, old_dentry, MAY_LINK); |
2893 | } | |
2894 | ||
1da177e4 LT |
2895 | static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) |
2896 | { | |
1da177e4 LT |
2897 | return may_link(dir, dentry, MAY_UNLINK); |
2898 | } | |
2899 | ||
2900 | static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) | |
2901 | { | |
2902 | return may_create(dir, dentry, SECCLASS_LNK_FILE); | |
2903 | } | |
2904 | ||
18bb1db3 | 2905 | static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) |
1da177e4 LT |
2906 | { |
2907 | return may_create(dir, dentry, SECCLASS_DIR); | |
2908 | } | |
2909 | ||
1da177e4 LT |
2910 | static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) |
2911 | { | |
2912 | return may_link(dir, dentry, MAY_RMDIR); | |
2913 | } | |
2914 | ||
1a67aafb | 2915 | static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 | 2916 | { |
1da177e4 LT |
2917 | return may_create(dir, dentry, inode_mode_to_security_class(mode)); |
2918 | } | |
2919 | ||
1da177e4 | 2920 | static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, |
828dfe1d | 2921 | struct inode *new_inode, struct dentry *new_dentry) |
1da177e4 LT |
2922 | { |
2923 | return may_rename(old_inode, old_dentry, new_inode, new_dentry); | |
2924 | } | |
2925 | ||
1da177e4 LT |
2926 | static int selinux_inode_readlink(struct dentry *dentry) |
2927 | { | |
88e67f3b DH |
2928 | const struct cred *cred = current_cred(); |
2929 | ||
2875fa00 | 2930 | return dentry_has_perm(cred, dentry, FILE__READ); |
1da177e4 LT |
2931 | } |
2932 | ||
bda0be7a N |
2933 | static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, |
2934 | bool rcu) | |
1da177e4 | 2935 | { |
88e67f3b | 2936 | const struct cred *cred = current_cred(); |
bda0be7a N |
2937 | struct common_audit_data ad; |
2938 | struct inode_security_struct *isec; | |
2939 | u32 sid; | |
1da177e4 | 2940 | |
bda0be7a N |
2941 | validate_creds(cred); |
2942 | ||
2943 | ad.type = LSM_AUDIT_DATA_DENTRY; | |
2944 | ad.u.dentry = dentry; | |
2945 | sid = cred_sid(cred); | |
5d226df4 AG |
2946 | isec = inode_security_rcu(inode, rcu); |
2947 | if (IS_ERR(isec)) | |
2948 | return PTR_ERR(isec); | |
bda0be7a | 2949 | |
e46e01ee SS |
2950 | return avc_has_perm(&selinux_state, |
2951 | sid, isec->sid, isec->sclass, FILE__READ, &ad); | |
1da177e4 LT |
2952 | } |
2953 | ||
d4cf970d EP |
2954 | static noinline int audit_inode_permission(struct inode *inode, |
2955 | u32 perms, u32 audited, u32 denied, | |
626b9740 | 2956 | int result, |
d4cf970d | 2957 | unsigned flags) |
1da177e4 | 2958 | { |
b782e0a6 | 2959 | struct common_audit_data ad; |
d4cf970d EP |
2960 | struct inode_security_struct *isec = inode->i_security; |
2961 | int rc; | |
2962 | ||
50c205f5 | 2963 | ad.type = LSM_AUDIT_DATA_INODE; |
d4cf970d EP |
2964 | ad.u.inode = inode; |
2965 | ||
6b6bc620 SS |
2966 | rc = slow_avc_audit(&selinux_state, |
2967 | current_sid(), isec->sid, isec->sclass, perms, | |
626b9740 | 2968 | audited, denied, result, &ad, flags); |
d4cf970d EP |
2969 | if (rc) |
2970 | return rc; | |
2971 | return 0; | |
2972 | } | |
2973 | ||
e74f71eb | 2974 | static int selinux_inode_permission(struct inode *inode, int mask) |
1da177e4 | 2975 | { |
88e67f3b | 2976 | const struct cred *cred = current_cred(); |
b782e0a6 EP |
2977 | u32 perms; |
2978 | bool from_access; | |
cf1dd1da | 2979 | unsigned flags = mask & MAY_NOT_BLOCK; |
2e334057 EP |
2980 | struct inode_security_struct *isec; |
2981 | u32 sid; | |
2982 | struct av_decision avd; | |
2983 | int rc, rc2; | |
2984 | u32 audited, denied; | |
1da177e4 | 2985 | |
b782e0a6 | 2986 | from_access = mask & MAY_ACCESS; |
d09ca739 EP |
2987 | mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
2988 | ||
b782e0a6 EP |
2989 | /* No permission to check. Existence test. */ |
2990 | if (!mask) | |
1da177e4 | 2991 | return 0; |
1da177e4 | 2992 | |
2e334057 | 2993 | validate_creds(cred); |
b782e0a6 | 2994 | |
2e334057 EP |
2995 | if (unlikely(IS_PRIVATE(inode))) |
2996 | return 0; | |
b782e0a6 EP |
2997 | |
2998 | perms = file_mask_to_av(inode->i_mode, mask); | |
2999 | ||
2e334057 | 3000 | sid = cred_sid(cred); |
5d226df4 AG |
3001 | isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK); |
3002 | if (IS_ERR(isec)) | |
3003 | return PTR_ERR(isec); | |
2e334057 | 3004 | |
6b6bc620 | 3005 | rc = avc_has_perm_noaudit(&selinux_state, |
3a28cff3 SS |
3006 | sid, isec->sid, isec->sclass, perms, |
3007 | (flags & MAY_NOT_BLOCK) ? AVC_NONBLOCKING : 0, | |
3008 | &avd); | |
2e334057 EP |
3009 | audited = avc_audit_required(perms, &avd, rc, |
3010 | from_access ? FILE__AUDIT_ACCESS : 0, | |
3011 | &denied); | |
3012 | if (likely(!audited)) | |
3013 | return rc; | |
3014 | ||
626b9740 | 3015 | rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags); |
2e334057 EP |
3016 | if (rc2) |
3017 | return rc2; | |
3018 | return rc; | |
1da177e4 LT |
3019 | } |
3020 | ||
3021 | static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
3022 | { | |
88e67f3b | 3023 | const struct cred *cred = current_cred(); |
ccb54478 | 3024 | struct inode *inode = d_backing_inode(dentry); |
bc6a6008 | 3025 | unsigned int ia_valid = iattr->ia_valid; |
95dbf739 | 3026 | __u32 av = FILE__WRITE; |
1da177e4 | 3027 | |
bc6a6008 AW |
3028 | /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ |
3029 | if (ia_valid & ATTR_FORCE) { | |
3030 | ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | | |
3031 | ATTR_FORCE); | |
3032 | if (!ia_valid) | |
3033 | return 0; | |
3034 | } | |
1da177e4 | 3035 | |
bc6a6008 AW |
3036 | if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | |
3037 | ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) | |
2875fa00 | 3038 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
1da177e4 | 3039 | |
aa8e712c | 3040 | if (selinux_policycap_openperm() && |
ccb54478 SS |
3041 | inode->i_sb->s_magic != SOCKFS_MAGIC && |
3042 | (ia_valid & ATTR_SIZE) && | |
3043 | !(ia_valid & ATTR_FILE)) | |
95dbf739 EP |
3044 | av |= FILE__OPEN; |
3045 | ||
3046 | return dentry_has_perm(cred, dentry, av); | |
1da177e4 LT |
3047 | } |
3048 | ||
3f7036a0 | 3049 | static int selinux_inode_getattr(const struct path *path) |
1da177e4 | 3050 | { |
3f7036a0 | 3051 | return path_has_perm(current_cred(), path, FILE__GETATTR); |
1da177e4 LT |
3052 | } |
3053 | ||
db59000a SS |
3054 | static bool has_cap_mac_admin(bool audit) |
3055 | { | |
3056 | const struct cred *cred = current_cred(); | |
3057 | int cap_audit = audit ? SECURITY_CAP_AUDIT : SECURITY_CAP_NOAUDIT; | |
3058 | ||
3059 | if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, cap_audit)) | |
3060 | return false; | |
3061 | if (cred_has_capability(cred, CAP_MAC_ADMIN, cap_audit, true)) | |
3062 | return false; | |
3063 | return true; | |
3064 | } | |
3065 | ||
8f0cfa52 DH |
3066 | static int selinux_inode_setxattr(struct dentry *dentry, const char *name, |
3067 | const void *value, size_t size, int flags) | |
1da177e4 | 3068 | { |
c6f493d6 | 3069 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3070 | struct inode_security_struct *isec; |
1da177e4 | 3071 | struct superblock_security_struct *sbsec; |
2bf49690 | 3072 | struct common_audit_data ad; |
275bb41e | 3073 | u32 newsid, sid = current_sid(); |
1da177e4 LT |
3074 | int rc = 0; |
3075 | ||
6b240306 EB |
3076 | if (strcmp(name, XATTR_NAME_SELINUX)) { |
3077 | rc = cap_inode_setxattr(dentry, name, value, size, flags); | |
3078 | if (rc) | |
3079 | return rc; | |
3080 | ||
3081 | /* Not an attribute we recognize, so just check the | |
3082 | ordinary setattr permission. */ | |
3083 | return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); | |
3084 | } | |
1da177e4 LT |
3085 | |
3086 | sbsec = inode->i_sb->s_security; | |
12f348b9 | 3087 | if (!(sbsec->flags & SBLABEL_MNT)) |
1da177e4 LT |
3088 | return -EOPNOTSUPP; |
3089 | ||
2e149670 | 3090 | if (!inode_owner_or_capable(inode)) |
1da177e4 LT |
3091 | return -EPERM; |
3092 | ||
50c205f5 | 3093 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 3094 | ad.u.dentry = dentry; |
1da177e4 | 3095 | |
20cdef8d | 3096 | isec = backing_inode_security(dentry); |
6b6bc620 SS |
3097 | rc = avc_has_perm(&selinux_state, |
3098 | sid, isec->sid, isec->sclass, | |
1da177e4 LT |
3099 | FILE__RELABELFROM, &ad); |
3100 | if (rc) | |
3101 | return rc; | |
3102 | ||
aa8e712c SS |
3103 | rc = security_context_to_sid(&selinux_state, value, size, &newsid, |
3104 | GFP_KERNEL); | |
12b29f34 | 3105 | if (rc == -EINVAL) { |
db59000a | 3106 | if (!has_cap_mac_admin(true)) { |
d6ea83ec EP |
3107 | struct audit_buffer *ab; |
3108 | size_t audit_size; | |
d6ea83ec EP |
3109 | |
3110 | /* We strip a nul only if it is at the end, otherwise the | |
3111 | * context contains a nul and we should audit that */ | |
e3fea3f7 | 3112 | if (value) { |
add24372 CIK |
3113 | const char *str = value; |
3114 | ||
e3fea3f7 AV |
3115 | if (str[size - 1] == '\0') |
3116 | audit_size = size - 1; | |
3117 | else | |
3118 | audit_size = size; | |
3119 | } else { | |
e3fea3f7 AV |
3120 | audit_size = 0; |
3121 | } | |
cdfb6b34 RGB |
3122 | ab = audit_log_start(audit_context(), |
3123 | GFP_ATOMIC, AUDIT_SELINUX_ERR); | |
d6ea83ec EP |
3124 | audit_log_format(ab, "op=setxattr invalid_context="); |
3125 | audit_log_n_untrustedstring(ab, value, audit_size); | |
3126 | audit_log_end(ab); | |
3127 | ||
12b29f34 | 3128 | return rc; |
d6ea83ec | 3129 | } |
aa8e712c SS |
3130 | rc = security_context_to_sid_force(&selinux_state, value, |
3131 | size, &newsid); | |
12b29f34 | 3132 | } |
1da177e4 LT |
3133 | if (rc) |
3134 | return rc; | |
3135 | ||
6b6bc620 SS |
3136 | rc = avc_has_perm(&selinux_state, |
3137 | sid, newsid, isec->sclass, | |
1da177e4 LT |
3138 | FILE__RELABELTO, &ad); |
3139 | if (rc) | |
3140 | return rc; | |
3141 | ||
aa8e712c SS |
3142 | rc = security_validate_transition(&selinux_state, isec->sid, newsid, |
3143 | sid, isec->sclass); | |
1da177e4 LT |
3144 | if (rc) |
3145 | return rc; | |
3146 | ||
6b6bc620 SS |
3147 | return avc_has_perm(&selinux_state, |
3148 | newsid, | |
1da177e4 LT |
3149 | sbsec->sid, |
3150 | SECCLASS_FILESYSTEM, | |
3151 | FILESYSTEM__ASSOCIATE, | |
3152 | &ad); | |
3153 | } | |
3154 | ||
8f0cfa52 | 3155 | static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, |
f5269710 | 3156 | const void *value, size_t size, |
8f0cfa52 | 3157 | int flags) |
1da177e4 | 3158 | { |
c6f493d6 | 3159 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3160 | struct inode_security_struct *isec; |
1da177e4 LT |
3161 | u32 newsid; |
3162 | int rc; | |
3163 | ||
3164 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
3165 | /* Not an attribute we recognize, so nothing to do. */ | |
3166 | return; | |
3167 | } | |
3168 | ||
aa8e712c SS |
3169 | rc = security_context_to_sid_force(&selinux_state, value, size, |
3170 | &newsid); | |
1da177e4 | 3171 | if (rc) { |
c103a91e | 3172 | pr_err("SELinux: unable to map context to SID" |
12b29f34 SS |
3173 | "for (%s, %lu), rc=%d\n", |
3174 | inode->i_sb->s_id, inode->i_ino, -rc); | |
1da177e4 LT |
3175 | return; |
3176 | } | |
3177 | ||
20cdef8d | 3178 | isec = backing_inode_security(dentry); |
9287aed2 | 3179 | spin_lock(&isec->lock); |
aa9c2669 | 3180 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3181 | isec->sid = newsid; |
6f3be9f5 | 3182 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3183 | spin_unlock(&isec->lock); |
aa9c2669 | 3184 | |
1da177e4 LT |
3185 | return; |
3186 | } | |
3187 | ||
8f0cfa52 | 3188 | static int selinux_inode_getxattr(struct dentry *dentry, const char *name) |
1da177e4 | 3189 | { |
88e67f3b DH |
3190 | const struct cred *cred = current_cred(); |
3191 | ||
2875fa00 | 3192 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3193 | } |
3194 | ||
828dfe1d | 3195 | static int selinux_inode_listxattr(struct dentry *dentry) |
1da177e4 | 3196 | { |
88e67f3b DH |
3197 | const struct cred *cred = current_cred(); |
3198 | ||
2875fa00 | 3199 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3200 | } |
3201 | ||
8f0cfa52 | 3202 | static int selinux_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 3203 | { |
6b240306 EB |
3204 | if (strcmp(name, XATTR_NAME_SELINUX)) { |
3205 | int rc = cap_inode_removexattr(dentry, name); | |
3206 | if (rc) | |
3207 | return rc; | |
3208 | ||
3209 | /* Not an attribute we recognize, so just check the | |
3210 | ordinary setattr permission. */ | |
3211 | return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); | |
3212 | } | |
1da177e4 LT |
3213 | |
3214 | /* No one is allowed to remove a SELinux security label. | |
3215 | You can change the label, but all data must be labeled. */ | |
3216 | return -EACCES; | |
3217 | } | |
3218 | ||
d381d8a9 | 3219 | /* |
abc69bb6 | 3220 | * Copy the inode security context value to the user. |
d381d8a9 JM |
3221 | * |
3222 | * Permission check is handled by selinux_inode_getxattr hook. | |
3223 | */ | |
ea861dfd | 3224 | static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc) |
1da177e4 | 3225 | { |
42492594 DQ |
3226 | u32 size; |
3227 | int error; | |
3228 | char *context = NULL; | |
20cdef8d | 3229 | struct inode_security_struct *isec; |
d381d8a9 | 3230 | |
8c8570fb DK |
3231 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) |
3232 | return -EOPNOTSUPP; | |
d381d8a9 | 3233 | |
abc69bb6 SS |
3234 | /* |
3235 | * If the caller has CAP_MAC_ADMIN, then get the raw context | |
3236 | * value even if it is not defined by current policy; otherwise, | |
3237 | * use the in-core value under current policy. | |
3238 | * Use the non-auditing forms of the permission checks since | |
3239 | * getxattr may be called by unprivileged processes commonly | |
3240 | * and lack of permission just means that we fall back to the | |
3241 | * in-core context value, not a denial. | |
3242 | */ | |
20cdef8d | 3243 | isec = inode_security(inode); |
db59000a | 3244 | if (has_cap_mac_admin(false)) |
aa8e712c SS |
3245 | error = security_sid_to_context_force(&selinux_state, |
3246 | isec->sid, &context, | |
abc69bb6 SS |
3247 | &size); |
3248 | else | |
aa8e712c SS |
3249 | error = security_sid_to_context(&selinux_state, isec->sid, |
3250 | &context, &size); | |
42492594 DQ |
3251 | if (error) |
3252 | return error; | |
3253 | error = size; | |
3254 | if (alloc) { | |
3255 | *buffer = context; | |
3256 | goto out_nofree; | |
3257 | } | |
3258 | kfree(context); | |
3259 | out_nofree: | |
3260 | return error; | |
1da177e4 LT |
3261 | } |
3262 | ||
3263 | static int selinux_inode_setsecurity(struct inode *inode, const char *name, | |
828dfe1d | 3264 | const void *value, size_t size, int flags) |
1da177e4 | 3265 | { |
2c97165b | 3266 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
53e0c2aa | 3267 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; |
1da177e4 LT |
3268 | u32 newsid; |
3269 | int rc; | |
3270 | ||
3271 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) | |
3272 | return -EOPNOTSUPP; | |
3273 | ||
53e0c2aa OM |
3274 | if (!(sbsec->flags & SBLABEL_MNT)) |
3275 | return -EOPNOTSUPP; | |
3276 | ||
1da177e4 LT |
3277 | if (!value || !size) |
3278 | return -EACCES; | |
3279 | ||
aa8e712c SS |
3280 | rc = security_context_to_sid(&selinux_state, value, size, &newsid, |
3281 | GFP_KERNEL); | |
1da177e4 LT |
3282 | if (rc) |
3283 | return rc; | |
3284 | ||
9287aed2 | 3285 | spin_lock(&isec->lock); |
aa9c2669 | 3286 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3287 | isec->sid = newsid; |
6f3be9f5 | 3288 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3289 | spin_unlock(&isec->lock); |
1da177e4 LT |
3290 | return 0; |
3291 | } | |
3292 | ||
3293 | static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) | |
3294 | { | |
3295 | const int len = sizeof(XATTR_NAME_SELINUX); | |
3296 | if (buffer && len <= buffer_size) | |
3297 | memcpy(buffer, XATTR_NAME_SELINUX, len); | |
3298 | return len; | |
3299 | } | |
3300 | ||
d6335d77 | 3301 | static void selinux_inode_getsecid(struct inode *inode, u32 *secid) |
713a04ae | 3302 | { |
e817c2f3 | 3303 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
713a04ae AD |
3304 | *secid = isec->sid; |
3305 | } | |
3306 | ||
56909eb3 VG |
3307 | static int selinux_inode_copy_up(struct dentry *src, struct cred **new) |
3308 | { | |
3309 | u32 sid; | |
3310 | struct task_security_struct *tsec; | |
3311 | struct cred *new_creds = *new; | |
3312 | ||
3313 | if (new_creds == NULL) { | |
3314 | new_creds = prepare_creds(); | |
3315 | if (!new_creds) | |
3316 | return -ENOMEM; | |
3317 | } | |
3318 | ||
3319 | tsec = new_creds->security; | |
3320 | /* Get label from overlay inode and set it in create_sid */ | |
3321 | selinux_inode_getsecid(d_inode(src), &sid); | |
3322 | tsec->create_sid = sid; | |
3323 | *new = new_creds; | |
3324 | return 0; | |
3325 | } | |
3326 | ||
19472b69 VG |
3327 | static int selinux_inode_copy_up_xattr(const char *name) |
3328 | { | |
3329 | /* The copy_up hook above sets the initial context on an inode, but we | |
3330 | * don't then want to overwrite it by blindly copying all the lower | |
3331 | * xattrs up. Instead, we have to filter out SELinux-related xattrs. | |
3332 | */ | |
3333 | if (strcmp(name, XATTR_NAME_SELINUX) == 0) | |
3334 | return 1; /* Discard */ | |
3335 | /* | |
3336 | * Any other attribute apart from SELINUX is not claimed, supported | |
3337 | * by selinux. | |
3338 | */ | |
3339 | return -EOPNOTSUPP; | |
3340 | } | |
3341 | ||
1da177e4 LT |
3342 | /* file security operations */ |
3343 | ||
788e7dd4 | 3344 | static int selinux_revalidate_file_permission(struct file *file, int mask) |
1da177e4 | 3345 | { |
88e67f3b | 3346 | const struct cred *cred = current_cred(); |
496ad9aa | 3347 | struct inode *inode = file_inode(file); |
1da177e4 | 3348 | |
1da177e4 LT |
3349 | /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ |
3350 | if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) | |
3351 | mask |= MAY_APPEND; | |
3352 | ||
389fb800 PM |
3353 | return file_has_perm(cred, file, |
3354 | file_mask_to_av(inode->i_mode, mask)); | |
1da177e4 LT |
3355 | } |
3356 | ||
788e7dd4 YN |
3357 | static int selinux_file_permission(struct file *file, int mask) |
3358 | { | |
496ad9aa | 3359 | struct inode *inode = file_inode(file); |
20dda18b | 3360 | struct file_security_struct *fsec = file->f_security; |
b197367e | 3361 | struct inode_security_struct *isec; |
20dda18b SS |
3362 | u32 sid = current_sid(); |
3363 | ||
389fb800 | 3364 | if (!mask) |
788e7dd4 YN |
3365 | /* No permission to check. Existence test. */ |
3366 | return 0; | |
788e7dd4 | 3367 | |
b197367e | 3368 | isec = inode_security(inode); |
20dda18b | 3369 | if (sid == fsec->sid && fsec->isid == isec->sid && |
6b6bc620 | 3370 | fsec->pseqno == avc_policy_seqno(&selinux_state)) |
83d49856 | 3371 | /* No change since file_open check. */ |
20dda18b SS |
3372 | return 0; |
3373 | ||
788e7dd4 YN |
3374 | return selinux_revalidate_file_permission(file, mask); |
3375 | } | |
3376 | ||
1da177e4 LT |
3377 | static int selinux_file_alloc_security(struct file *file) |
3378 | { | |
3379 | return file_alloc_security(file); | |
3380 | } | |
3381 | ||
3382 | static void selinux_file_free_security(struct file *file) | |
3383 | { | |
3384 | file_free_security(file); | |
3385 | } | |
3386 | ||
fa1aa143 JVS |
3387 | /* |
3388 | * Check whether a task has the ioctl permission and cmd | |
3389 | * operation to an inode. | |
3390 | */ | |
1d2a168a | 3391 | static int ioctl_has_perm(const struct cred *cred, struct file *file, |
fa1aa143 JVS |
3392 | u32 requested, u16 cmd) |
3393 | { | |
3394 | struct common_audit_data ad; | |
3395 | struct file_security_struct *fsec = file->f_security; | |
3396 | struct inode *inode = file_inode(file); | |
20cdef8d | 3397 | struct inode_security_struct *isec; |
fa1aa143 JVS |
3398 | struct lsm_ioctlop_audit ioctl; |
3399 | u32 ssid = cred_sid(cred); | |
3400 | int rc; | |
3401 | u8 driver = cmd >> 8; | |
3402 | u8 xperm = cmd & 0xff; | |
3403 | ||
3404 | ad.type = LSM_AUDIT_DATA_IOCTL_OP; | |
3405 | ad.u.op = &ioctl; | |
3406 | ad.u.op->cmd = cmd; | |
3407 | ad.u.op->path = file->f_path; | |
3408 | ||
3409 | if (ssid != fsec->sid) { | |
6b6bc620 SS |
3410 | rc = avc_has_perm(&selinux_state, |
3411 | ssid, fsec->sid, | |
fa1aa143 JVS |
3412 | SECCLASS_FD, |
3413 | FD__USE, | |
3414 | &ad); | |
3415 | if (rc) | |
3416 | goto out; | |
3417 | } | |
3418 | ||
3419 | if (unlikely(IS_PRIVATE(inode))) | |
3420 | return 0; | |
3421 | ||
20cdef8d | 3422 | isec = inode_security(inode); |
6b6bc620 SS |
3423 | rc = avc_has_extended_perms(&selinux_state, |
3424 | ssid, isec->sid, isec->sclass, | |
3425 | requested, driver, xperm, &ad); | |
fa1aa143 JVS |
3426 | out: |
3427 | return rc; | |
3428 | } | |
3429 | ||
1da177e4 LT |
3430 | static int selinux_file_ioctl(struct file *file, unsigned int cmd, |
3431 | unsigned long arg) | |
3432 | { | |
88e67f3b | 3433 | const struct cred *cred = current_cred(); |
0b24dcb7 | 3434 | int error = 0; |
1da177e4 | 3435 | |
0b24dcb7 EP |
3436 | switch (cmd) { |
3437 | case FIONREAD: | |
3438 | /* fall through */ | |
3439 | case FIBMAP: | |
3440 | /* fall through */ | |
3441 | case FIGETBSZ: | |
3442 | /* fall through */ | |
2f99c369 | 3443 | case FS_IOC_GETFLAGS: |
0b24dcb7 | 3444 | /* fall through */ |
2f99c369 | 3445 | case FS_IOC_GETVERSION: |
0b24dcb7 EP |
3446 | error = file_has_perm(cred, file, FILE__GETATTR); |
3447 | break; | |
1da177e4 | 3448 | |
2f99c369 | 3449 | case FS_IOC_SETFLAGS: |
0b24dcb7 | 3450 | /* fall through */ |
2f99c369 | 3451 | case FS_IOC_SETVERSION: |
0b24dcb7 EP |
3452 | error = file_has_perm(cred, file, FILE__SETATTR); |
3453 | break; | |
3454 | ||
3455 | /* sys_ioctl() checks */ | |
3456 | case FIONBIO: | |
3457 | /* fall through */ | |
3458 | case FIOASYNC: | |
3459 | error = file_has_perm(cred, file, 0); | |
3460 | break; | |
1da177e4 | 3461 | |
0b24dcb7 EP |
3462 | case KDSKBENT: |
3463 | case KDSKBSENT: | |
6a9de491 | 3464 | error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, |
8e4ff6f2 | 3465 | SECURITY_CAP_AUDIT, true); |
0b24dcb7 EP |
3466 | break; |
3467 | ||
3468 | /* default case assumes that the command will go | |
3469 | * to the file's ioctl() function. | |
3470 | */ | |
3471 | default: | |
fa1aa143 | 3472 | error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); |
0b24dcb7 EP |
3473 | } |
3474 | return error; | |
1da177e4 LT |
3475 | } |
3476 | ||
fcaaade1 SS |
3477 | static int default_noexec; |
3478 | ||
1da177e4 LT |
3479 | static int file_map_prot_check(struct file *file, unsigned long prot, int shared) |
3480 | { | |
88e67f3b | 3481 | const struct cred *cred = current_cred(); |
be0554c9 | 3482 | u32 sid = cred_sid(cred); |
d84f4f99 | 3483 | int rc = 0; |
88e67f3b | 3484 | |
fcaaade1 | 3485 | if (default_noexec && |
892e8cac SS |
3486 | (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) || |
3487 | (!shared && (prot & PROT_WRITE)))) { | |
1da177e4 LT |
3488 | /* |
3489 | * We are making executable an anonymous mapping or a | |
3490 | * private file mapping that will also be writable. | |
3491 | * This has an additional check. | |
3492 | */ | |
6b6bc620 SS |
3493 | rc = avc_has_perm(&selinux_state, |
3494 | sid, sid, SECCLASS_PROCESS, | |
be0554c9 | 3495 | PROCESS__EXECMEM, NULL); |
1da177e4 | 3496 | if (rc) |
d84f4f99 | 3497 | goto error; |
1da177e4 | 3498 | } |
1da177e4 LT |
3499 | |
3500 | if (file) { | |
3501 | /* read access is always possible with a mapping */ | |
3502 | u32 av = FILE__READ; | |
3503 | ||
3504 | /* write access only matters if the mapping is shared */ | |
3505 | if (shared && (prot & PROT_WRITE)) | |
3506 | av |= FILE__WRITE; | |
3507 | ||
3508 | if (prot & PROT_EXEC) | |
3509 | av |= FILE__EXECUTE; | |
3510 | ||
88e67f3b | 3511 | return file_has_perm(cred, file, av); |
1da177e4 | 3512 | } |
d84f4f99 DH |
3513 | |
3514 | error: | |
3515 | return rc; | |
1da177e4 LT |
3516 | } |
3517 | ||
e5467859 | 3518 | static int selinux_mmap_addr(unsigned long addr) |
1da177e4 | 3519 | { |
b1d9e6b0 | 3520 | int rc = 0; |
1da177e4 | 3521 | |
a2551df7 | 3522 | if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { |
98883bfd | 3523 | u32 sid = current_sid(); |
6b6bc620 SS |
3524 | rc = avc_has_perm(&selinux_state, |
3525 | sid, sid, SECCLASS_MEMPROTECT, | |
ed032189 | 3526 | MEMPROTECT__MMAP_ZERO, NULL); |
84336d1a EP |
3527 | } |
3528 | ||
98883bfd | 3529 | return rc; |
e5467859 | 3530 | } |
1da177e4 | 3531 | |
e5467859 AV |
3532 | static int selinux_mmap_file(struct file *file, unsigned long reqprot, |
3533 | unsigned long prot, unsigned long flags) | |
3534 | { | |
3ba4bf5f SS |
3535 | struct common_audit_data ad; |
3536 | int rc; | |
3537 | ||
3538 | if (file) { | |
3539 | ad.type = LSM_AUDIT_DATA_FILE; | |
3540 | ad.u.file = file; | |
3541 | rc = inode_has_perm(current_cred(), file_inode(file), | |
3542 | FILE__MAP, &ad); | |
3543 | if (rc) | |
3544 | return rc; | |
3545 | } | |
3546 | ||
aa8e712c | 3547 | if (selinux_state.checkreqprot) |
1da177e4 LT |
3548 | prot = reqprot; |
3549 | ||
3550 | return file_map_prot_check(file, prot, | |
3551 | (flags & MAP_TYPE) == MAP_SHARED); | |
3552 | } | |
3553 | ||
3554 | static int selinux_file_mprotect(struct vm_area_struct *vma, | |
3555 | unsigned long reqprot, | |
3556 | unsigned long prot) | |
3557 | { | |
88e67f3b | 3558 | const struct cred *cred = current_cred(); |
be0554c9 | 3559 | u32 sid = cred_sid(cred); |
1da177e4 | 3560 | |
aa8e712c | 3561 | if (selinux_state.checkreqprot) |
1da177e4 LT |
3562 | prot = reqprot; |
3563 | ||
fcaaade1 SS |
3564 | if (default_noexec && |
3565 | (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { | |
d541bbee | 3566 | int rc = 0; |
db4c9641 SS |
3567 | if (vma->vm_start >= vma->vm_mm->start_brk && |
3568 | vma->vm_end <= vma->vm_mm->brk) { | |
6b6bc620 SS |
3569 | rc = avc_has_perm(&selinux_state, |
3570 | sid, sid, SECCLASS_PROCESS, | |
be0554c9 | 3571 | PROCESS__EXECHEAP, NULL); |
db4c9641 | 3572 | } else if (!vma->vm_file && |
c2316dbf SS |
3573 | ((vma->vm_start <= vma->vm_mm->start_stack && |
3574 | vma->vm_end >= vma->vm_mm->start_stack) || | |
d17af505 | 3575 | vma_is_stack_for_current(vma))) { |
6b6bc620 SS |
3576 | rc = avc_has_perm(&selinux_state, |
3577 | sid, sid, SECCLASS_PROCESS, | |
be0554c9 | 3578 | PROCESS__EXECSTACK, NULL); |
db4c9641 SS |
3579 | } else if (vma->vm_file && vma->anon_vma) { |
3580 | /* | |
3581 | * We are making executable a file mapping that has | |
3582 | * had some COW done. Since pages might have been | |
3583 | * written, check ability to execute the possibly | |
3584 | * modified content. This typically should only | |
3585 | * occur for text relocations. | |
3586 | */ | |
d84f4f99 | 3587 | rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); |
db4c9641 | 3588 | } |