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> | |
442155c1 DH |
51 | #include <linux/fs_context.h> |
52 | #include <linux/fs_parser.h> | |
1da177e4 LT |
53 | #include <linux/netfilter_ipv4.h> |
54 | #include <linux/netfilter_ipv6.h> | |
55 | #include <linux/tty.h> | |
56 | #include <net/icmp.h> | |
227b60f5 | 57 | #include <net/ip.h> /* for local_port_range[] */ |
1da177e4 | 58 | #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ |
47180068 | 59 | #include <net/inet_connection_sock.h> |
220deb96 | 60 | #include <net/net_namespace.h> |
d621d35e | 61 | #include <net/netlabel.h> |
f5269710 | 62 | #include <linux/uaccess.h> |
1da177e4 | 63 | #include <asm/ioctls.h> |
60063497 | 64 | #include <linux/atomic.h> |
1da177e4 LT |
65 | #include <linux/bitops.h> |
66 | #include <linux/interrupt.h> | |
67 | #include <linux/netdevice.h> /* for network interface checks */ | |
77954983 | 68 | #include <net/netlink.h> |
1da177e4 LT |
69 | #include <linux/tcp.h> |
70 | #include <linux/udp.h> | |
2ee92d46 | 71 | #include <linux/dccp.h> |
d452930f RH |
72 | #include <linux/sctp.h> |
73 | #include <net/sctp/structs.h> | |
1da177e4 LT |
74 | #include <linux/quota.h> |
75 | #include <linux/un.h> /* for Unix socket types */ | |
76 | #include <net/af_unix.h> /* for Unix socket types */ | |
77 | #include <linux/parser.h> | |
78 | #include <linux/nfs_mount.h> | |
79 | #include <net/ipv6.h> | |
80 | #include <linux/hugetlb.h> | |
81 | #include <linux/personality.h> | |
1da177e4 | 82 | #include <linux/audit.h> |
6931dfc9 | 83 | #include <linux/string.h> |
23970741 | 84 | #include <linux/mutex.h> |
f06febc9 | 85 | #include <linux/posix-timers.h> |
00234592 | 86 | #include <linux/syslog.h> |
3486740a | 87 | #include <linux/user_namespace.h> |
44fc7ea0 | 88 | #include <linux/export.h> |
40401530 AV |
89 | #include <linux/msg.h> |
90 | #include <linux/shm.h> | |
ec27c356 | 91 | #include <linux/bpf.h> |
e262e32d | 92 | #include <uapi/linux/mount.h> |
1da177e4 LT |
93 | |
94 | #include "avc.h" | |
95 | #include "objsec.h" | |
96 | #include "netif.h" | |
224dfbd8 | 97 | #include "netnode.h" |
3e112172 | 98 | #include "netport.h" |
409dcf31 | 99 | #include "ibpkey.h" |
d28d1e08 | 100 | #include "xfrm.h" |
c60475bf | 101 | #include "netlabel.h" |
9d57a7f9 | 102 | #include "audit.h" |
7b98a585 | 103 | #include "avc_ss.h" |
1da177e4 | 104 | |
aa8e712c SS |
105 | struct selinux_state selinux_state; |
106 | ||
d621d35e | 107 | /* SECMARK reference count */ |
56a4ca99 | 108 | static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); |
d621d35e | 109 | |
1da177e4 | 110 | #ifdef CONFIG_SECURITY_SELINUX_DEVELOP |
aa8e712c | 111 | static int selinux_enforcing_boot; |
1da177e4 LT |
112 | |
113 | static int __init enforcing_setup(char *str) | |
114 | { | |
f5269710 | 115 | unsigned long enforcing; |
29707b20 | 116 | if (!kstrtoul(str, 0, &enforcing)) |
aa8e712c | 117 | selinux_enforcing_boot = enforcing ? 1 : 0; |
1da177e4 LT |
118 | return 1; |
119 | } | |
120 | __setup("enforcing=", enforcing_setup); | |
aa8e712c SS |
121 | #else |
122 | #define selinux_enforcing_boot 1 | |
1da177e4 LT |
123 | #endif |
124 | ||
be6ec88f | 125 | int selinux_enabled __lsm_ro_after_init = 1; |
1da177e4 | 126 | #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM |
1da177e4 LT |
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); | |
135 | #endif | |
136 | ||
aa8e712c SS |
137 | static unsigned int selinux_checkreqprot_boot = |
138 | CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE; | |
139 | ||
140 | static int __init checkreqprot_setup(char *str) | |
141 | { | |
142 | unsigned long checkreqprot; | |
143 | ||
144 | if (!kstrtoul(str, 0, &checkreqprot)) | |
145 | selinux_checkreqprot_boot = checkreqprot ? 1 : 0; | |
146 | return 1; | |
147 | } | |
148 | __setup("checkreqprot=", checkreqprot_setup); | |
149 | ||
d621d35e PM |
150 | /** |
151 | * selinux_secmark_enabled - Check to see if SECMARK is currently enabled | |
152 | * | |
153 | * Description: | |
154 | * This function checks the SECMARK reference counter to see if any SECMARK | |
155 | * targets are currently configured, if the reference counter is greater than | |
156 | * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is | |
2be4d74f CP |
157 | * enabled, false (0) if SECMARK is disabled. If the always_check_network |
158 | * policy capability is enabled, SECMARK is always considered enabled. | |
d621d35e PM |
159 | * |
160 | */ | |
161 | static int selinux_secmark_enabled(void) | |
162 | { | |
aa8e712c SS |
163 | return (selinux_policycap_alwaysnetwork() || |
164 | atomic_read(&selinux_secmark_refcount)); | |
2be4d74f CP |
165 | } |
166 | ||
167 | /** | |
168 | * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled | |
169 | * | |
170 | * Description: | |
171 | * This function checks if NetLabel or labeled IPSEC is enabled. Returns true | |
172 | * (1) if any are enabled or false (0) if neither are enabled. If the | |
173 | * always_check_network policy capability is enabled, peer labeling | |
174 | * is always considered enabled. | |
175 | * | |
176 | */ | |
177 | static int selinux_peerlbl_enabled(void) | |
178 | { | |
aa8e712c SS |
179 | return (selinux_policycap_alwaysnetwork() || |
180 | netlbl_enabled() || selinux_xfrm_enabled()); | |
d621d35e PM |
181 | } |
182 | ||
615e51fd PM |
183 | static int selinux_netcache_avc_callback(u32 event) |
184 | { | |
185 | if (event == AVC_CALLBACK_RESET) { | |
186 | sel_netif_flush(); | |
187 | sel_netnode_flush(); | |
188 | sel_netport_flush(); | |
189 | synchronize_net(); | |
190 | } | |
191 | return 0; | |
192 | } | |
193 | ||
8f408ab6 DJ |
194 | static int selinux_lsm_notifier_avc_callback(u32 event) |
195 | { | |
409dcf31 DJ |
196 | if (event == AVC_CALLBACK_RESET) { |
197 | sel_ib_pkey_flush(); | |
8f408ab6 | 198 | call_lsm_notifier(LSM_POLICY_CHANGE, NULL); |
409dcf31 | 199 | } |
8f408ab6 DJ |
200 | |
201 | return 0; | |
202 | } | |
203 | ||
d84f4f99 DH |
204 | /* |
205 | * initialise the security for the init task | |
206 | */ | |
207 | static void cred_init_security(void) | |
1da177e4 | 208 | { |
3b11a1de | 209 | struct cred *cred = (struct cred *) current->real_cred; |
1da177e4 LT |
210 | struct task_security_struct *tsec; |
211 | ||
bbd3662a | 212 | tsec = selinux_cred(cred); |
d84f4f99 | 213 | tsec->osid = tsec->sid = SECINITSID_KERNEL; |
1da177e4 LT |
214 | } |
215 | ||
88e67f3b DH |
216 | /* |
217 | * get the security ID of a set of credentials | |
218 | */ | |
219 | static inline u32 cred_sid(const struct cred *cred) | |
220 | { | |
221 | const struct task_security_struct *tsec; | |
222 | ||
0c6cfa62 | 223 | tsec = selinux_cred(cred); |
88e67f3b DH |
224 | return tsec->sid; |
225 | } | |
226 | ||
275bb41e | 227 | /* |
3b11a1de | 228 | * get the objective security ID of a task |
275bb41e DH |
229 | */ |
230 | static inline u32 task_sid(const struct task_struct *task) | |
231 | { | |
275bb41e DH |
232 | u32 sid; |
233 | ||
234 | rcu_read_lock(); | |
88e67f3b | 235 | sid = cred_sid(__task_cred(task)); |
275bb41e DH |
236 | rcu_read_unlock(); |
237 | return sid; | |
238 | } | |
239 | ||
88e67f3b DH |
240 | /* Allocate and free functions for each kind of security blob. */ |
241 | ||
1da177e4 LT |
242 | static int inode_alloc_security(struct inode *inode) |
243 | { | |
afb1cbe3 | 244 | struct inode_security_struct *isec = selinux_inode(inode); |
275bb41e | 245 | u32 sid = current_sid(); |
1da177e4 | 246 | |
9287aed2 | 247 | spin_lock_init(&isec->lock); |
1da177e4 | 248 | INIT_LIST_HEAD(&isec->list); |
1da177e4 LT |
249 | isec->inode = inode; |
250 | isec->sid = SECINITSID_UNLABELED; | |
251 | isec->sclass = SECCLASS_FILE; | |
275bb41e | 252 | isec->task_sid = sid; |
42059112 | 253 | isec->initialized = LABEL_INVALID; |
1da177e4 LT |
254 | |
255 | return 0; | |
256 | } | |
257 | ||
5d226df4 AG |
258 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); |
259 | ||
260 | /* | |
261 | * Try reloading inode security labels that have been marked as invalid. The | |
262 | * @may_sleep parameter indicates when sleeping and thus reloading labels is | |
42059112 | 263 | * allowed; when set to false, returns -ECHILD when the label is |
e9193288 | 264 | * invalid. The @dentry parameter should be set to a dentry of the inode. |
5d226df4 AG |
265 | */ |
266 | static int __inode_security_revalidate(struct inode *inode, | |
e9193288 | 267 | struct dentry *dentry, |
5d226df4 AG |
268 | bool may_sleep) |
269 | { | |
80788c22 | 270 | struct inode_security_struct *isec = selinux_inode(inode); |
5d226df4 AG |
271 | |
272 | might_sleep_if(may_sleep); | |
273 | ||
aa8e712c SS |
274 | if (selinux_state.initialized && |
275 | isec->initialized != LABEL_INITIALIZED) { | |
5d226df4 AG |
276 | if (!may_sleep) |
277 | return -ECHILD; | |
278 | ||
279 | /* | |
280 | * Try reloading the inode security label. This will fail if | |
281 | * @opt_dentry is NULL and no dentry for this inode can be | |
282 | * found; in that case, continue using the old label. | |
283 | */ | |
e9193288 | 284 | inode_doinit_with_dentry(inode, dentry); |
5d226df4 AG |
285 | } |
286 | return 0; | |
287 | } | |
288 | ||
5d226df4 AG |
289 | static struct inode_security_struct *inode_security_novalidate(struct inode *inode) |
290 | { | |
80788c22 | 291 | return selinux_inode(inode); |
5d226df4 AG |
292 | } |
293 | ||
294 | static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu) | |
295 | { | |
296 | int error; | |
297 | ||
298 | error = __inode_security_revalidate(inode, NULL, !rcu); | |
299 | if (error) | |
300 | return ERR_PTR(error); | |
80788c22 | 301 | return selinux_inode(inode); |
5d226df4 AG |
302 | } |
303 | ||
83da53c5 AG |
304 | /* |
305 | * Get the security label of an inode. | |
306 | */ | |
307 | static struct inode_security_struct *inode_security(struct inode *inode) | |
308 | { | |
5d226df4 | 309 | __inode_security_revalidate(inode, NULL, true); |
80788c22 | 310 | return selinux_inode(inode); |
83da53c5 AG |
311 | } |
312 | ||
2c97165b PM |
313 | static struct inode_security_struct *backing_inode_security_novalidate(struct dentry *dentry) |
314 | { | |
315 | struct inode *inode = d_backing_inode(dentry); | |
316 | ||
80788c22 | 317 | return selinux_inode(inode); |
2c97165b PM |
318 | } |
319 | ||
83da53c5 AG |
320 | /* |
321 | * Get the security label of a dentry's backing inode. | |
322 | */ | |
323 | static struct inode_security_struct *backing_inode_security(struct dentry *dentry) | |
324 | { | |
325 | struct inode *inode = d_backing_inode(dentry); | |
326 | ||
5d226df4 | 327 | __inode_security_revalidate(inode, dentry, true); |
80788c22 | 328 | return selinux_inode(inode); |
83da53c5 AG |
329 | } |
330 | ||
1da177e4 LT |
331 | static void inode_free_security(struct inode *inode) |
332 | { | |
80788c22 | 333 | struct inode_security_struct *isec = selinux_inode(inode); |
afb1cbe3 | 334 | struct superblock_security_struct *sbsec; |
1da177e4 | 335 | |
afb1cbe3 CS |
336 | if (!isec) |
337 | return; | |
338 | sbsec = inode->i_sb->s_security; | |
9629d04a WL |
339 | /* |
340 | * As not all inode security structures are in a list, we check for | |
341 | * empty list outside of the lock to make sure that we won't waste | |
342 | * time taking a lock doing nothing. | |
343 | * | |
344 | * The list_del_init() function can be safely called more than once. | |
345 | * It should not be possible for this function to be called with | |
346 | * concurrent list_add(), but for better safety against future changes | |
347 | * in the code, we use list_empty_careful() here. | |
348 | */ | |
349 | if (!list_empty_careful(&isec->list)) { | |
350 | spin_lock(&sbsec->isec_lock); | |
1da177e4 | 351 | list_del_init(&isec->list); |
9629d04a WL |
352 | spin_unlock(&sbsec->isec_lock); |
353 | } | |
1da177e4 LT |
354 | } |
355 | ||
356 | static int file_alloc_security(struct file *file) | |
357 | { | |
33bf60ca | 358 | struct file_security_struct *fsec = selinux_file(file); |
275bb41e | 359 | u32 sid = current_sid(); |
1da177e4 | 360 | |
275bb41e DH |
361 | fsec->sid = sid; |
362 | fsec->fown_sid = sid; | |
1da177e4 LT |
363 | |
364 | return 0; | |
365 | } | |
366 | ||
1da177e4 LT |
367 | static int superblock_alloc_security(struct super_block *sb) |
368 | { | |
369 | struct superblock_security_struct *sbsec; | |
370 | ||
89d155ef | 371 | sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); |
1da177e4 LT |
372 | if (!sbsec) |
373 | return -ENOMEM; | |
374 | ||
bc7e982b | 375 | mutex_init(&sbsec->lock); |
1da177e4 LT |
376 | INIT_LIST_HEAD(&sbsec->isec_head); |
377 | spin_lock_init(&sbsec->isec_lock); | |
1da177e4 LT |
378 | sbsec->sb = sb; |
379 | sbsec->sid = SECINITSID_UNLABELED; | |
380 | sbsec->def_sid = SECINITSID_FILE; | |
c312feb2 | 381 | sbsec->mntpoint_sid = SECINITSID_UNLABELED; |
1da177e4 LT |
382 | sb->s_security = sbsec; |
383 | ||
384 | return 0; | |
385 | } | |
386 | ||
387 | static void superblock_free_security(struct super_block *sb) | |
388 | { | |
389 | struct superblock_security_struct *sbsec = sb->s_security; | |
1da177e4 LT |
390 | sb->s_security = NULL; |
391 | kfree(sbsec); | |
392 | } | |
393 | ||
bd323655 AV |
394 | struct selinux_mnt_opts { |
395 | const char *fscontext, *context, *rootcontext, *defcontext; | |
396 | }; | |
397 | ||
204cc0cc AV |
398 | static void selinux_free_mnt_opts(void *mnt_opts) |
399 | { | |
bd323655 AV |
400 | struct selinux_mnt_opts *opts = mnt_opts; |
401 | kfree(opts->fscontext); | |
402 | kfree(opts->context); | |
403 | kfree(opts->rootcontext); | |
404 | kfree(opts->defcontext); | |
204cc0cc AV |
405 | kfree(opts); |
406 | } | |
407 | ||
1da177e4 LT |
408 | static inline int inode_doinit(struct inode *inode) |
409 | { | |
410 | return inode_doinit_with_dentry(inode, NULL); | |
411 | } | |
412 | ||
413 | enum { | |
31e87930 | 414 | Opt_error = -1, |
442155c1 DH |
415 | Opt_context = 0, |
416 | Opt_defcontext = 1, | |
1da177e4 | 417 | Opt_fscontext = 2, |
442155c1 DH |
418 | Opt_rootcontext = 3, |
419 | Opt_seclabel = 4, | |
1da177e4 LT |
420 | }; |
421 | ||
da3d76ab | 422 | #define A(s, has_arg) {#s, sizeof(#s) - 1, Opt_##s, has_arg} |
169d68ef AV |
423 | static struct { |
424 | const char *name; | |
425 | int len; | |
426 | int opt; | |
427 | bool has_arg; | |
428 | } tokens[] = { | |
da3d76ab AV |
429 | A(context, true), |
430 | A(fscontext, true), | |
431 | A(defcontext, true), | |
432 | A(rootcontext, true), | |
433 | A(seclabel, false), | |
1da177e4 | 434 | }; |
169d68ef AV |
435 | #undef A |
436 | ||
437 | static int match_opt_prefix(char *s, int l, char **arg) | |
438 | { | |
439 | int i; | |
440 | ||
441 | for (i = 0; i < ARRAY_SIZE(tokens); i++) { | |
442 | size_t len = tokens[i].len; | |
443 | if (len > l || memcmp(s, tokens[i].name, len)) | |
444 | continue; | |
445 | if (tokens[i].has_arg) { | |
446 | if (len == l || s[len] != '=') | |
447 | continue; | |
448 | *arg = s + len + 1; | |
449 | } else if (len != l) | |
450 | continue; | |
451 | return tokens[i].opt; | |
452 | } | |
453 | return Opt_error; | |
454 | } | |
1da177e4 LT |
455 | |
456 | #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" | |
457 | ||
c312feb2 EP |
458 | static int may_context_mount_sb_relabel(u32 sid, |
459 | struct superblock_security_struct *sbsec, | |
275bb41e | 460 | const struct cred *cred) |
c312feb2 | 461 | { |
0c6cfa62 | 462 | const struct task_security_struct *tsec = selinux_cred(cred); |
c312feb2 EP |
463 | int rc; |
464 | ||
6b6bc620 SS |
465 | rc = avc_has_perm(&selinux_state, |
466 | tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
c312feb2 EP |
467 | FILESYSTEM__RELABELFROM, NULL); |
468 | if (rc) | |
469 | return rc; | |
470 | ||
6b6bc620 SS |
471 | rc = avc_has_perm(&selinux_state, |
472 | tsec->sid, sid, SECCLASS_FILESYSTEM, | |
c312feb2 EP |
473 | FILESYSTEM__RELABELTO, NULL); |
474 | return rc; | |
475 | } | |
476 | ||
0808925e EP |
477 | static int may_context_mount_inode_relabel(u32 sid, |
478 | struct superblock_security_struct *sbsec, | |
275bb41e | 479 | const struct cred *cred) |
0808925e | 480 | { |
0c6cfa62 | 481 | const struct task_security_struct *tsec = selinux_cred(cred); |
0808925e | 482 | int rc; |
6b6bc620 SS |
483 | rc = avc_has_perm(&selinux_state, |
484 | tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
0808925e EP |
485 | FILESYSTEM__RELABELFROM, NULL); |
486 | if (rc) | |
487 | return rc; | |
488 | ||
6b6bc620 SS |
489 | rc = avc_has_perm(&selinux_state, |
490 | sid, sbsec->sid, SECCLASS_FILESYSTEM, | |
0808925e EP |
491 | FILESYSTEM__ASSOCIATE, NULL); |
492 | return rc; | |
493 | } | |
494 | ||
a83d6dda | 495 | static int selinux_is_genfs_special_handling(struct super_block *sb) |
b43e725d | 496 | { |
a83d6dda OM |
497 | /* Special handling. Genfs but also in-core setxattr handler */ |
498 | return !strcmp(sb->s_type->name, "sysfs") || | |
d5f3a5f6 MS |
499 | !strcmp(sb->s_type->name, "pstore") || |
500 | !strcmp(sb->s_type->name, "debugfs") || | |
a2c7c6fb | 501 | !strcmp(sb->s_type->name, "tracefs") || |
2651225b | 502 | !strcmp(sb->s_type->name, "rootfs") || |
aa8e712c | 503 | (selinux_policycap_cgroupseclabel() && |
2651225b SS |
504 | (!strcmp(sb->s_type->name, "cgroup") || |
505 | !strcmp(sb->s_type->name, "cgroup2"))); | |
b43e725d EP |
506 | } |
507 | ||
a83d6dda OM |
508 | static int selinux_is_sblabel_mnt(struct super_block *sb) |
509 | { | |
510 | struct superblock_security_struct *sbsec = sb->s_security; | |
511 | ||
512 | /* | |
513 | * IMPORTANT: Double-check logic in this function when adding a new | |
514 | * SECURITY_FS_USE_* definition! | |
515 | */ | |
516 | BUILD_BUG_ON(SECURITY_FS_USE_MAX != 7); | |
517 | ||
518 | switch (sbsec->behavior) { | |
519 | case SECURITY_FS_USE_XATTR: | |
520 | case SECURITY_FS_USE_TRANS: | |
521 | case SECURITY_FS_USE_TASK: | |
522 | case SECURITY_FS_USE_NATIVE: | |
523 | return 1; | |
524 | ||
525 | case SECURITY_FS_USE_GENFS: | |
526 | return selinux_is_genfs_special_handling(sb); | |
527 | ||
528 | /* Never allow relabeling on context mounts */ | |
529 | case SECURITY_FS_USE_MNTPOINT: | |
530 | case SECURITY_FS_USE_NONE: | |
531 | default: | |
532 | return 0; | |
533 | } | |
534 | } | |
535 | ||
c9180a57 | 536 | static int sb_finish_set_opts(struct super_block *sb) |
1da177e4 | 537 | { |
1da177e4 | 538 | struct superblock_security_struct *sbsec = sb->s_security; |
c9180a57 | 539 | struct dentry *root = sb->s_root; |
c6f493d6 | 540 | struct inode *root_inode = d_backing_inode(root); |
c9180a57 | 541 | int rc = 0; |
1da177e4 | 542 | |
c9180a57 EP |
543 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { |
544 | /* Make sure that the xattr handler exists and that no | |
545 | error other than -ENODATA is returned by getxattr on | |
546 | the root directory. -ENODATA is ok, as this may be | |
547 | the first boot of the SELinux kernel before we have | |
548 | assigned xattr values to the filesystem. */ | |
5d6c3191 | 549 | if (!(root_inode->i_opflags & IOP_XATTR)) { |
c103a91e | 550 | pr_warn("SELinux: (dev %s, type %s) has no " |
29b1deb2 | 551 | "xattr support\n", sb->s_id, sb->s_type->name); |
c9180a57 EP |
552 | rc = -EOPNOTSUPP; |
553 | goto out; | |
554 | } | |
5d6c3191 AG |
555 | |
556 | rc = __vfs_getxattr(root, root_inode, XATTR_NAME_SELINUX, NULL, 0); | |
c9180a57 EP |
557 | if (rc < 0 && rc != -ENODATA) { |
558 | if (rc == -EOPNOTSUPP) | |
c103a91e | 559 | pr_warn("SELinux: (dev %s, type " |
29b1deb2 LT |
560 | "%s) has no security xattr handler\n", |
561 | sb->s_id, sb->s_type->name); | |
c9180a57 | 562 | else |
c103a91e | 563 | pr_warn("SELinux: (dev %s, type " |
29b1deb2 LT |
564 | "%s) getxattr errno %d\n", sb->s_id, |
565 | sb->s_type->name, -rc); | |
c9180a57 EP |
566 | goto out; |
567 | } | |
568 | } | |
1da177e4 | 569 | |
eadcabc6 | 570 | sbsec->flags |= SE_SBINITIALIZED; |
0b4d3452 SM |
571 | |
572 | /* | |
573 | * Explicitly set or clear SBLABEL_MNT. It's not sufficient to simply | |
574 | * leave the flag untouched because sb_clone_mnt_opts might be handing | |
575 | * us a superblock that needs the flag to be cleared. | |
576 | */ | |
b43e725d | 577 | if (selinux_is_sblabel_mnt(sb)) |
12f348b9 | 578 | sbsec->flags |= SBLABEL_MNT; |
0b4d3452 SM |
579 | else |
580 | sbsec->flags &= ~SBLABEL_MNT; | |
ddd29ec6 | 581 | |
c9180a57 EP |
582 | /* Initialize the root inode. */ |
583 | rc = inode_doinit_with_dentry(root_inode, root); | |
1da177e4 | 584 | |
c9180a57 EP |
585 | /* Initialize any other inodes associated with the superblock, e.g. |
586 | inodes created prior to initial policy load or inodes created | |
587 | during get_sb by a pseudo filesystem that directly | |
588 | populates itself. */ | |
589 | spin_lock(&sbsec->isec_lock); | |
8d64124a | 590 | while (!list_empty(&sbsec->isec_head)) { |
c9180a57 | 591 | struct inode_security_struct *isec = |
8d64124a | 592 | list_first_entry(&sbsec->isec_head, |
c9180a57 EP |
593 | struct inode_security_struct, list); |
594 | struct inode *inode = isec->inode; | |
923190d3 | 595 | list_del_init(&isec->list); |
c9180a57 EP |
596 | spin_unlock(&sbsec->isec_lock); |
597 | inode = igrab(inode); | |
598 | if (inode) { | |
599 | if (!IS_PRIVATE(inode)) | |
600 | inode_doinit(inode); | |
601 | iput(inode); | |
602 | } | |
603 | spin_lock(&sbsec->isec_lock); | |
c9180a57 EP |
604 | } |
605 | spin_unlock(&sbsec->isec_lock); | |
606 | out: | |
607 | return rc; | |
608 | } | |
1da177e4 | 609 | |
c9180a57 EP |
610 | static int bad_option(struct superblock_security_struct *sbsec, char flag, |
611 | u32 old_sid, u32 new_sid) | |
612 | { | |
0d90a7ec DQ |
613 | char mnt_flags = sbsec->flags & SE_MNTMASK; |
614 | ||
c9180a57 | 615 | /* check if the old mount command had the same options */ |
0d90a7ec | 616 | if (sbsec->flags & SE_SBINITIALIZED) |
c9180a57 EP |
617 | if (!(sbsec->flags & flag) || |
618 | (old_sid != new_sid)) | |
619 | return 1; | |
620 | ||
621 | /* check if we were passed the same options twice, | |
622 | * aka someone passed context=a,context=b | |
623 | */ | |
0d90a7ec DQ |
624 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
625 | if (mnt_flags & flag) | |
c9180a57 EP |
626 | return 1; |
627 | return 0; | |
628 | } | |
e0007529 | 629 | |
bd323655 AV |
630 | static int parse_sid(struct super_block *sb, const char *s, u32 *sid) |
631 | { | |
632 | int rc = security_context_str_to_sid(&selinux_state, s, | |
633 | sid, GFP_KERNEL); | |
634 | if (rc) | |
635 | pr_warn("SELinux: security_context_str_to_sid" | |
636 | "(%s) failed for (dev %s, type %s) errno=%d\n", | |
637 | s, sb->s_id, sb->s_type->name, rc); | |
638 | return rc; | |
639 | } | |
640 | ||
c9180a57 EP |
641 | /* |
642 | * Allow filesystems with binary mount data to explicitly set mount point | |
643 | * labeling information. | |
644 | */ | |
e0007529 | 645 | static int selinux_set_mnt_opts(struct super_block *sb, |
204cc0cc | 646 | void *mnt_opts, |
649f6e77 DQ |
647 | unsigned long kern_flags, |
648 | unsigned long *set_kern_flags) | |
c9180a57 | 649 | { |
275bb41e | 650 | const struct cred *cred = current_cred(); |
c9180a57 | 651 | struct superblock_security_struct *sbsec = sb->s_security; |
83da53c5 | 652 | struct dentry *root = sbsec->sb->s_root; |
bd323655 | 653 | struct selinux_mnt_opts *opts = mnt_opts; |
2c97165b | 654 | struct inode_security_struct *root_isec; |
c9180a57 EP |
655 | u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; |
656 | u32 defcontext_sid = 0; | |
bd323655 | 657 | int rc = 0; |
c9180a57 EP |
658 | |
659 | mutex_lock(&sbsec->lock); | |
660 | ||
aa8e712c | 661 | if (!selinux_state.initialized) { |
bd323655 | 662 | if (!opts) { |
c9180a57 EP |
663 | /* Defer initialization until selinux_complete_init, |
664 | after the initial policy is loaded and the security | |
665 | server is ready to handle calls. */ | |
c9180a57 EP |
666 | goto out; |
667 | } | |
668 | rc = -EINVAL; | |
c103a91e | 669 | pr_warn("SELinux: Unable to set superblock options " |
744ba35e | 670 | "before the security server is initialized\n"); |
1da177e4 | 671 | goto out; |
c9180a57 | 672 | } |
649f6e77 DQ |
673 | if (kern_flags && !set_kern_flags) { |
674 | /* Specifying internal flags without providing a place to | |
675 | * place the results is not allowed */ | |
676 | rc = -EINVAL; | |
677 | goto out; | |
678 | } | |
1da177e4 | 679 | |
e0007529 EP |
680 | /* |
681 | * Binary mount data FS will come through this function twice. Once | |
682 | * from an explicit call and once from the generic calls from the vfs. | |
683 | * Since the generic VFS calls will not contain any security mount data | |
684 | * we need to skip the double mount verification. | |
685 | * | |
686 | * This does open a hole in which we will not notice if the first | |
687 | * mount using this sb set explict options and a second mount using | |
688 | * this sb does not set any security options. (The first options | |
689 | * will be used for both mounts) | |
690 | */ | |
0d90a7ec | 691 | if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) |
bd323655 | 692 | && !opts) |
f5269710 | 693 | goto out; |
e0007529 | 694 | |
2c97165b PM |
695 | root_isec = backing_inode_security_novalidate(root); |
696 | ||
c9180a57 EP |
697 | /* |
698 | * parse the mount options, check if they are valid sids. | |
699 | * also check if someone is trying to mount the same sb more | |
700 | * than once with different security options. | |
701 | */ | |
bd323655 AV |
702 | if (opts) { |
703 | if (opts->fscontext) { | |
704 | rc = parse_sid(sb, opts->fscontext, &fscontext_sid); | |
705 | if (rc) | |
706 | goto out; | |
c9180a57 EP |
707 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, |
708 | fscontext_sid)) | |
709 | goto out_double_mount; | |
c9180a57 | 710 | sbsec->flags |= FSCONTEXT_MNT; |
bd323655 AV |
711 | } |
712 | if (opts->context) { | |
713 | rc = parse_sid(sb, opts->context, &context_sid); | |
714 | if (rc) | |
715 | goto out; | |
c9180a57 EP |
716 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, |
717 | context_sid)) | |
718 | goto out_double_mount; | |
c9180a57 | 719 | sbsec->flags |= CONTEXT_MNT; |
bd323655 AV |
720 | } |
721 | if (opts->rootcontext) { | |
722 | rc = parse_sid(sb, opts->rootcontext, &rootcontext_sid); | |
723 | if (rc) | |
724 | goto out; | |
c9180a57 EP |
725 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, |
726 | rootcontext_sid)) | |
727 | goto out_double_mount; | |
c9180a57 | 728 | sbsec->flags |= ROOTCONTEXT_MNT; |
bd323655 AV |
729 | } |
730 | if (opts->defcontext) { | |
731 | rc = parse_sid(sb, opts->defcontext, &defcontext_sid); | |
732 | if (rc) | |
733 | goto out; | |
c9180a57 EP |
734 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, |
735 | defcontext_sid)) | |
736 | goto out_double_mount; | |
c9180a57 | 737 | sbsec->flags |= DEFCONTEXT_MNT; |
1da177e4 | 738 | } |
c9180a57 EP |
739 | } |
740 | ||
0d90a7ec | 741 | if (sbsec->flags & SE_SBINITIALIZED) { |
c9180a57 | 742 | /* previously mounted with options, but not on this attempt? */ |
bd323655 | 743 | if ((sbsec->flags & SE_MNTMASK) && !opts) |
c9180a57 EP |
744 | goto out_double_mount; |
745 | rc = 0; | |
746 | goto out; | |
747 | } | |
748 | ||
089be43e | 749 | if (strcmp(sb->s_type->name, "proc") == 0) |
134509d5 SS |
750 | sbsec->flags |= SE_SBPROC | SE_SBGENFS; |
751 | ||
8e014720 | 752 | if (!strcmp(sb->s_type->name, "debugfs") || |
6a391183 | 753 | !strcmp(sb->s_type->name, "tracefs") || |
8e014720 | 754 | !strcmp(sb->s_type->name, "sysfs") || |
901ef845 AM |
755 | !strcmp(sb->s_type->name, "pstore") || |
756 | !strcmp(sb->s_type->name, "cgroup") || | |
757 | !strcmp(sb->s_type->name, "cgroup2")) | |
134509d5 | 758 | sbsec->flags |= SE_SBGENFS; |
c9180a57 | 759 | |
eb9ae686 DQ |
760 | if (!sbsec->behavior) { |
761 | /* | |
762 | * Determine the labeling behavior to use for this | |
763 | * filesystem type. | |
764 | */ | |
aa8e712c | 765 | rc = security_fs_use(&selinux_state, sb); |
eb9ae686 | 766 | if (rc) { |
c103a91e | 767 | pr_warn("%s: security_fs_use(%s) returned %d\n", |
eb9ae686 DQ |
768 | __func__, sb->s_type->name, rc); |
769 | goto out; | |
770 | } | |
c9180a57 | 771 | } |
aad82892 SF |
772 | |
773 | /* | |
01593d32 SS |
774 | * If this is a user namespace mount and the filesystem type is not |
775 | * explicitly whitelisted, then no contexts are allowed on the command | |
776 | * line and security labels must be ignored. | |
aad82892 | 777 | */ |
01593d32 SS |
778 | if (sb->s_user_ns != &init_user_ns && |
779 | strcmp(sb->s_type->name, "tmpfs") && | |
780 | strcmp(sb->s_type->name, "ramfs") && | |
781 | strcmp(sb->s_type->name, "devpts")) { | |
aad82892 SF |
782 | if (context_sid || fscontext_sid || rootcontext_sid || |
783 | defcontext_sid) { | |
784 | rc = -EACCES; | |
785 | goto out; | |
786 | } | |
787 | if (sbsec->behavior == SECURITY_FS_USE_XATTR) { | |
788 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; | |
aa8e712c SS |
789 | rc = security_transition_sid(&selinux_state, |
790 | current_sid(), | |
791 | current_sid(), | |
aad82892 SF |
792 | SECCLASS_FILE, NULL, |
793 | &sbsec->mntpoint_sid); | |
794 | if (rc) | |
795 | goto out; | |
796 | } | |
797 | goto out_set_opts; | |
798 | } | |
799 | ||
c9180a57 EP |
800 | /* sets the context of the superblock for the fs being mounted. */ |
801 | if (fscontext_sid) { | |
275bb41e | 802 | rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); |
1da177e4 | 803 | if (rc) |
c9180a57 | 804 | goto out; |
1da177e4 | 805 | |
c9180a57 | 806 | sbsec->sid = fscontext_sid; |
c312feb2 EP |
807 | } |
808 | ||
809 | /* | |
810 | * Switch to using mount point labeling behavior. | |
811 | * sets the label used on all file below the mountpoint, and will set | |
812 | * the superblock context if not already set. | |
813 | */ | |
eb9ae686 DQ |
814 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) { |
815 | sbsec->behavior = SECURITY_FS_USE_NATIVE; | |
816 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
817 | } | |
818 | ||
c9180a57 EP |
819 | if (context_sid) { |
820 | if (!fscontext_sid) { | |
275bb41e DH |
821 | rc = may_context_mount_sb_relabel(context_sid, sbsec, |
822 | cred); | |
b04ea3ce | 823 | if (rc) |
c9180a57 EP |
824 | goto out; |
825 | sbsec->sid = context_sid; | |
b04ea3ce | 826 | } else { |
275bb41e DH |
827 | rc = may_context_mount_inode_relabel(context_sid, sbsec, |
828 | cred); | |
b04ea3ce | 829 | if (rc) |
c9180a57 | 830 | goto out; |
b04ea3ce | 831 | } |
c9180a57 EP |
832 | if (!rootcontext_sid) |
833 | rootcontext_sid = context_sid; | |
1da177e4 | 834 | |
c9180a57 | 835 | sbsec->mntpoint_sid = context_sid; |
c312feb2 | 836 | sbsec->behavior = SECURITY_FS_USE_MNTPOINT; |
1da177e4 LT |
837 | } |
838 | ||
c9180a57 | 839 | if (rootcontext_sid) { |
275bb41e DH |
840 | rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, |
841 | cred); | |
0808925e | 842 | if (rc) |
c9180a57 | 843 | goto out; |
0808925e | 844 | |
c9180a57 | 845 | root_isec->sid = rootcontext_sid; |
6f3be9f5 | 846 | root_isec->initialized = LABEL_INITIALIZED; |
0808925e EP |
847 | } |
848 | ||
c9180a57 | 849 | if (defcontext_sid) { |
eb9ae686 DQ |
850 | if (sbsec->behavior != SECURITY_FS_USE_XATTR && |
851 | sbsec->behavior != SECURITY_FS_USE_NATIVE) { | |
c9180a57 | 852 | rc = -EINVAL; |
c103a91e | 853 | pr_warn("SELinux: defcontext option is " |
c9180a57 EP |
854 | "invalid for this filesystem type\n"); |
855 | goto out; | |
1da177e4 LT |
856 | } |
857 | ||
c9180a57 EP |
858 | if (defcontext_sid != sbsec->def_sid) { |
859 | rc = may_context_mount_inode_relabel(defcontext_sid, | |
275bb41e | 860 | sbsec, cred); |
c9180a57 EP |
861 | if (rc) |
862 | goto out; | |
863 | } | |
1da177e4 | 864 | |
c9180a57 | 865 | sbsec->def_sid = defcontext_sid; |
1da177e4 LT |
866 | } |
867 | ||
aad82892 | 868 | out_set_opts: |
c9180a57 | 869 | rc = sb_finish_set_opts(sb); |
1da177e4 | 870 | out: |
c9180a57 | 871 | mutex_unlock(&sbsec->lock); |
1da177e4 | 872 | return rc; |
c9180a57 EP |
873 | out_double_mount: |
874 | rc = -EINVAL; | |
c103a91e | 875 | pr_warn("SELinux: mount invalid. Same superblock, different " |
bd323655 AV |
876 | "security settings for (dev %s, type %s)\n", sb->s_id, |
877 | sb->s_type->name); | |
c9180a57 | 878 | goto out; |
1da177e4 LT |
879 | } |
880 | ||
094f7b69 JL |
881 | static int selinux_cmp_sb_context(const struct super_block *oldsb, |
882 | const struct super_block *newsb) | |
883 | { | |
884 | struct superblock_security_struct *old = oldsb->s_security; | |
885 | struct superblock_security_struct *new = newsb->s_security; | |
886 | char oldflags = old->flags & SE_MNTMASK; | |
887 | char newflags = new->flags & SE_MNTMASK; | |
888 | ||
889 | if (oldflags != newflags) | |
890 | goto mismatch; | |
891 | if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid) | |
892 | goto mismatch; | |
893 | if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid) | |
894 | goto mismatch; | |
895 | if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid) | |
896 | goto mismatch; | |
897 | if (oldflags & ROOTCONTEXT_MNT) { | |
83da53c5 AG |
898 | struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root); |
899 | struct inode_security_struct *newroot = backing_inode_security(newsb->s_root); | |
094f7b69 JL |
900 | if (oldroot->sid != newroot->sid) |
901 | goto mismatch; | |
902 | } | |
903 | return 0; | |
904 | mismatch: | |
c103a91e | 905 | pr_warn("SELinux: mount invalid. Same superblock, " |
094f7b69 JL |
906 | "different security settings for (dev %s, " |
907 | "type %s)\n", newsb->s_id, newsb->s_type->name); | |
908 | return -EBUSY; | |
909 | } | |
910 | ||
911 | static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, | |
0b4d3452 SM |
912 | struct super_block *newsb, |
913 | unsigned long kern_flags, | |
914 | unsigned long *set_kern_flags) | |
1da177e4 | 915 | { |
0b4d3452 | 916 | int rc = 0; |
c9180a57 EP |
917 | const struct superblock_security_struct *oldsbsec = oldsb->s_security; |
918 | struct superblock_security_struct *newsbsec = newsb->s_security; | |
1da177e4 | 919 | |
c9180a57 EP |
920 | int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); |
921 | int set_context = (oldsbsec->flags & CONTEXT_MNT); | |
922 | int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); | |
1da177e4 | 923 | |
0f5e6420 EP |
924 | /* |
925 | * if the parent was able to be mounted it clearly had no special lsm | |
e8c26255 | 926 | * mount options. thus we can safely deal with this superblock later |
0f5e6420 | 927 | */ |
aa8e712c | 928 | if (!selinux_state.initialized) |
094f7b69 | 929 | return 0; |
c9180a57 | 930 | |
0b4d3452 SM |
931 | /* |
932 | * Specifying internal flags without providing a place to | |
933 | * place the results is not allowed. | |
934 | */ | |
935 | if (kern_flags && !set_kern_flags) | |
936 | return -EINVAL; | |
937 | ||
c9180a57 | 938 | /* how can we clone if the old one wasn't set up?? */ |
0d90a7ec | 939 | BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); |
c9180a57 | 940 | |
094f7b69 | 941 | /* if fs is reusing a sb, make sure that the contexts match */ |
3815a245 BF |
942 | if (newsbsec->flags & SE_SBINITIALIZED) { |
943 | if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) | |
944 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
094f7b69 | 945 | return selinux_cmp_sb_context(oldsb, newsb); |
3815a245 | 946 | } |
5a552617 | 947 | |
c9180a57 EP |
948 | mutex_lock(&newsbsec->lock); |
949 | ||
950 | newsbsec->flags = oldsbsec->flags; | |
951 | ||
952 | newsbsec->sid = oldsbsec->sid; | |
953 | newsbsec->def_sid = oldsbsec->def_sid; | |
954 | newsbsec->behavior = oldsbsec->behavior; | |
955 | ||
0b4d3452 SM |
956 | if (newsbsec->behavior == SECURITY_FS_USE_NATIVE && |
957 | !(kern_flags & SECURITY_LSM_NATIVE_LABELS) && !set_context) { | |
aa8e712c | 958 | rc = security_fs_use(&selinux_state, newsb); |
0b4d3452 SM |
959 | if (rc) |
960 | goto out; | |
961 | } | |
962 | ||
963 | if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !set_context) { | |
964 | newsbsec->behavior = SECURITY_FS_USE_NATIVE; | |
965 | *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; | |
966 | } | |
967 | ||
c9180a57 EP |
968 | if (set_context) { |
969 | u32 sid = oldsbsec->mntpoint_sid; | |
970 | ||
971 | if (!set_fscontext) | |
972 | newsbsec->sid = sid; | |
973 | if (!set_rootcontext) { | |
83da53c5 | 974 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); |
c9180a57 EP |
975 | newisec->sid = sid; |
976 | } | |
977 | newsbsec->mntpoint_sid = sid; | |
1da177e4 | 978 | } |
c9180a57 | 979 | if (set_rootcontext) { |
83da53c5 AG |
980 | const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root); |
981 | struct inode_security_struct *newisec = backing_inode_security(newsb->s_root); | |
1da177e4 | 982 | |
c9180a57 | 983 | newisec->sid = oldisec->sid; |
1da177e4 LT |
984 | } |
985 | ||
c9180a57 | 986 | sb_finish_set_opts(newsb); |
0b4d3452 | 987 | out: |
c9180a57 | 988 | mutex_unlock(&newsbsec->lock); |
0b4d3452 | 989 | return rc; |
c9180a57 EP |
990 | } |
991 | ||
ba641862 | 992 | static int selinux_add_opt(int token, const char *s, void **mnt_opts) |
c9180a57 | 993 | { |
ba641862 | 994 | struct selinux_mnt_opts *opts = *mnt_opts; |
1da177e4 | 995 | |
da3d76ab | 996 | if (token == Opt_seclabel) /* eaten and completely ignored */ |
169d68ef | 997 | return 0; |
e0007529 | 998 | |
ba641862 AV |
999 | if (!opts) { |
1000 | opts = kzalloc(sizeof(struct selinux_mnt_opts), GFP_KERNEL); | |
1001 | if (!opts) | |
1002 | return -ENOMEM; | |
1003 | *mnt_opts = opts; | |
c9180a57 | 1004 | } |
ba641862 AV |
1005 | if (!s) |
1006 | return -ENOMEM; | |
1007 | switch (token) { | |
1008 | case Opt_context: | |
1009 | if (opts->context || opts->defcontext) | |
1010 | goto Einval; | |
1011 | opts->context = s; | |
1012 | break; | |
1013 | case Opt_fscontext: | |
1014 | if (opts->fscontext) | |
1015 | goto Einval; | |
1016 | opts->fscontext = s; | |
1017 | break; | |
1018 | case Opt_rootcontext: | |
1019 | if (opts->rootcontext) | |
1020 | goto Einval; | |
1021 | opts->rootcontext = s; | |
1022 | break; | |
1023 | case Opt_defcontext: | |
1024 | if (opts->context || opts->defcontext) | |
1025 | goto Einval; | |
1026 | opts->defcontext = s; | |
1027 | break; | |
c9180a57 | 1028 | } |
e0007529 | 1029 | return 0; |
ba641862 AV |
1030 | Einval: |
1031 | pr_warn(SEL_MOUNT_FAIL_MSG); | |
ba641862 | 1032 | return -EINVAL; |
1da177e4 | 1033 | } |
e0007529 | 1034 | |
757cbe59 AV |
1035 | static int selinux_add_mnt_opt(const char *option, const char *val, int len, |
1036 | void **mnt_opts) | |
c9180a57 | 1037 | { |
757cbe59 AV |
1038 | int token = Opt_error; |
1039 | int rc, i; | |
e0007529 | 1040 | |
757cbe59 AV |
1041 | for (i = 0; i < ARRAY_SIZE(tokens); i++) { |
1042 | if (strcmp(option, tokens[i].name) == 0) { | |
1043 | token = tokens[i].opt; | |
1044 | break; | |
169d68ef | 1045 | } |
757cbe59 | 1046 | } |
e0007529 | 1047 | |
757cbe59 AV |
1048 | if (token == Opt_error) |
1049 | return -EINVAL; | |
e0007529 | 1050 | |
757cbe59 AV |
1051 | if (token != Opt_seclabel) |
1052 | val = kmemdup_nul(val, len, GFP_KERNEL); | |
1053 | rc = selinux_add_opt(token, val, mnt_opts); | |
1054 | if (unlikely(rc)) { | |
1055 | kfree(val); | |
1056 | if (*mnt_opts) { | |
169d68ef AV |
1057 | selinux_free_mnt_opts(*mnt_opts); |
1058 | *mnt_opts = NULL; | |
1da177e4 | 1059 | } |
1da177e4 | 1060 | } |
e0007529 EP |
1061 | return rc; |
1062 | } | |
1da177e4 | 1063 | |
e3489f89 | 1064 | static int show_sid(struct seq_file *m, u32 sid) |
2069f457 | 1065 | { |
e3489f89 AV |
1066 | char *context = NULL; |
1067 | u32 len; | |
1068 | int rc; | |
11689d47 | 1069 | |
e3489f89 AV |
1070 | rc = security_sid_to_context(&selinux_state, sid, |
1071 | &context, &len); | |
1072 | if (!rc) { | |
1073 | bool has_comma = context && strchr(context, ','); | |
2069f457 | 1074 | |
442155c1 | 1075 | seq_putc(m, '='); |
2069f457 EP |
1076 | if (has_comma) |
1077 | seq_putc(m, '\"'); | |
e3489f89 | 1078 | seq_escape(m, context, "\"\n\\"); |
2069f457 EP |
1079 | if (has_comma) |
1080 | seq_putc(m, '\"'); | |
1081 | } | |
e3489f89 AV |
1082 | kfree(context); |
1083 | return rc; | |
2069f457 EP |
1084 | } |
1085 | ||
1086 | static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) | |
1087 | { | |
e3489f89 | 1088 | struct superblock_security_struct *sbsec = sb->s_security; |
2069f457 EP |
1089 | int rc; |
1090 | ||
e3489f89 AV |
1091 | if (!(sbsec->flags & SE_SBINITIALIZED)) |
1092 | return 0; | |
2069f457 | 1093 | |
e3489f89 AV |
1094 | if (!selinux_state.initialized) |
1095 | return 0; | |
2069f457 | 1096 | |
e3489f89 AV |
1097 | if (sbsec->flags & FSCONTEXT_MNT) { |
1098 | seq_putc(m, ','); | |
1099 | seq_puts(m, FSCONTEXT_STR); | |
1100 | rc = show_sid(m, sbsec->sid); | |
1101 | if (rc) | |
1102 | return rc; | |
1103 | } | |
1104 | if (sbsec->flags & CONTEXT_MNT) { | |
1105 | seq_putc(m, ','); | |
1106 | seq_puts(m, CONTEXT_STR); | |
1107 | rc = show_sid(m, sbsec->mntpoint_sid); | |
1108 | if (rc) | |
1109 | return rc; | |
1110 | } | |
1111 | if (sbsec->flags & DEFCONTEXT_MNT) { | |
1112 | seq_putc(m, ','); | |
1113 | seq_puts(m, DEFCONTEXT_STR); | |
1114 | rc = show_sid(m, sbsec->def_sid); | |
1115 | if (rc) | |
1116 | return rc; | |
1117 | } | |
1118 | if (sbsec->flags & ROOTCONTEXT_MNT) { | |
1119 | struct dentry *root = sbsec->sb->s_root; | |
1120 | struct inode_security_struct *isec = backing_inode_security(root); | |
1121 | seq_putc(m, ','); | |
1122 | seq_puts(m, ROOTCONTEXT_STR); | |
1123 | rc = show_sid(m, isec->sid); | |
1124 | if (rc) | |
1125 | return rc; | |
1126 | } | |
1127 | if (sbsec->flags & SBLABEL_MNT) { | |
1128 | seq_putc(m, ','); | |
442155c1 | 1129 | seq_puts(m, SECLABEL_STR); |
e3489f89 AV |
1130 | } |
1131 | return 0; | |
2069f457 EP |
1132 | } |
1133 | ||
1da177e4 LT |
1134 | static inline u16 inode_mode_to_security_class(umode_t mode) |
1135 | { | |
1136 | switch (mode & S_IFMT) { | |
1137 | case S_IFSOCK: | |
1138 | return SECCLASS_SOCK_FILE; | |
1139 | case S_IFLNK: | |
1140 | return SECCLASS_LNK_FILE; | |
1141 | case S_IFREG: | |
1142 | return SECCLASS_FILE; | |
1143 | case S_IFBLK: | |
1144 | return SECCLASS_BLK_FILE; | |
1145 | case S_IFDIR: | |
1146 | return SECCLASS_DIR; | |
1147 | case S_IFCHR: | |
1148 | return SECCLASS_CHR_FILE; | |
1149 | case S_IFIFO: | |
1150 | return SECCLASS_FIFO_FILE; | |
1151 | ||
1152 | } | |
1153 | ||
1154 | return SECCLASS_FILE; | |
1155 | } | |
1156 | ||
13402580 JM |
1157 | static inline int default_protocol_stream(int protocol) |
1158 | { | |
1159 | return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); | |
1160 | } | |
1161 | ||
1162 | static inline int default_protocol_dgram(int protocol) | |
1163 | { | |
1164 | return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); | |
1165 | } | |
1166 | ||
1da177e4 LT |
1167 | static inline u16 socket_type_to_security_class(int family, int type, int protocol) |
1168 | { | |
aa8e712c | 1169 | int extsockclass = selinux_policycap_extsockclass(); |
da69a530 | 1170 | |
1da177e4 LT |
1171 | switch (family) { |
1172 | case PF_UNIX: | |
1173 | switch (type) { | |
1174 | case SOCK_STREAM: | |
1175 | case SOCK_SEQPACKET: | |
1176 | return SECCLASS_UNIX_STREAM_SOCKET; | |
1177 | case SOCK_DGRAM: | |
2a764b52 | 1178 | case SOCK_RAW: |
1da177e4 LT |
1179 | return SECCLASS_UNIX_DGRAM_SOCKET; |
1180 | } | |
1181 | break; | |
1182 | case PF_INET: | |
1183 | case PF_INET6: | |
1184 | switch (type) { | |
1185 | case SOCK_STREAM: | |
da69a530 | 1186 | case SOCK_SEQPACKET: |
13402580 JM |
1187 | if (default_protocol_stream(protocol)) |
1188 | return SECCLASS_TCP_SOCKET; | |
da69a530 SS |
1189 | else if (extsockclass && protocol == IPPROTO_SCTP) |
1190 | return SECCLASS_SCTP_SOCKET; | |
13402580 JM |
1191 | else |
1192 | return SECCLASS_RAWIP_SOCKET; | |
1da177e4 | 1193 | case SOCK_DGRAM: |
13402580 JM |
1194 | if (default_protocol_dgram(protocol)) |
1195 | return SECCLASS_UDP_SOCKET; | |
ef37979a SS |
1196 | else if (extsockclass && (protocol == IPPROTO_ICMP || |
1197 | protocol == IPPROTO_ICMPV6)) | |
da69a530 | 1198 | return SECCLASS_ICMP_SOCKET; |
13402580 JM |
1199 | else |
1200 | return SECCLASS_RAWIP_SOCKET; | |
2ee92d46 JM |
1201 | case SOCK_DCCP: |
1202 | return SECCLASS_DCCP_SOCKET; | |
13402580 | 1203 | default: |
1da177e4 LT |
1204 | return SECCLASS_RAWIP_SOCKET; |
1205 | } | |
1206 | break; | |
1207 | case PF_NETLINK: | |
1208 | switch (protocol) { | |
1209 | case NETLINK_ROUTE: | |
1210 | return SECCLASS_NETLINK_ROUTE_SOCKET; | |
7f1fb60c | 1211 | case NETLINK_SOCK_DIAG: |
1da177e4 LT |
1212 | return SECCLASS_NETLINK_TCPDIAG_SOCKET; |
1213 | case NETLINK_NFLOG: | |
1214 | return SECCLASS_NETLINK_NFLOG_SOCKET; | |
1215 | case NETLINK_XFRM: | |
1216 | return SECCLASS_NETLINK_XFRM_SOCKET; | |
1217 | case NETLINK_SELINUX: | |
1218 | return SECCLASS_NETLINK_SELINUX_SOCKET; | |
6c6d2e9b SS |
1219 | case NETLINK_ISCSI: |
1220 | return SECCLASS_NETLINK_ISCSI_SOCKET; | |
1da177e4 LT |
1221 | case NETLINK_AUDIT: |
1222 | return SECCLASS_NETLINK_AUDIT_SOCKET; | |
6c6d2e9b SS |
1223 | case NETLINK_FIB_LOOKUP: |
1224 | return SECCLASS_NETLINK_FIB_LOOKUP_SOCKET; | |
1225 | case NETLINK_CONNECTOR: | |
1226 | return SECCLASS_NETLINK_CONNECTOR_SOCKET; | |
1227 | case NETLINK_NETFILTER: | |
1228 | return SECCLASS_NETLINK_NETFILTER_SOCKET; | |
1da177e4 LT |
1229 | case NETLINK_DNRTMSG: |
1230 | return SECCLASS_NETLINK_DNRT_SOCKET; | |
0c9b7942 JM |
1231 | case NETLINK_KOBJECT_UEVENT: |
1232 | return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; | |
6c6d2e9b SS |
1233 | case NETLINK_GENERIC: |
1234 | return SECCLASS_NETLINK_GENERIC_SOCKET; | |
1235 | case NETLINK_SCSITRANSPORT: | |
1236 | return SECCLASS_NETLINK_SCSITRANSPORT_SOCKET; | |
1237 | case NETLINK_RDMA: | |
1238 | return SECCLASS_NETLINK_RDMA_SOCKET; | |
1239 | case NETLINK_CRYPTO: | |
1240 | return SECCLASS_NETLINK_CRYPTO_SOCKET; | |
1da177e4 LT |
1241 | default: |
1242 | return SECCLASS_NETLINK_SOCKET; | |
1243 | } | |
1244 | case PF_PACKET: | |
1245 | return SECCLASS_PACKET_SOCKET; | |
1246 | case PF_KEY: | |
1247 | return SECCLASS_KEY_SOCKET; | |
3e3ff15e CP |
1248 | case PF_APPLETALK: |
1249 | return SECCLASS_APPLETALK_SOCKET; | |
1da177e4 LT |
1250 | } |
1251 | ||
da69a530 SS |
1252 | if (extsockclass) { |
1253 | switch (family) { | |
1254 | case PF_AX25: | |
1255 | return SECCLASS_AX25_SOCKET; | |
1256 | case PF_IPX: | |
1257 | return SECCLASS_IPX_SOCKET; | |
1258 | case PF_NETROM: | |
1259 | return SECCLASS_NETROM_SOCKET; | |
da69a530 SS |
1260 | case PF_ATMPVC: |
1261 | return SECCLASS_ATMPVC_SOCKET; | |
1262 | case PF_X25: | |
1263 | return SECCLASS_X25_SOCKET; | |
1264 | case PF_ROSE: | |
1265 | return SECCLASS_ROSE_SOCKET; | |
1266 | case PF_DECnet: | |
1267 | return SECCLASS_DECNET_SOCKET; | |
1268 | case PF_ATMSVC: | |
1269 | return SECCLASS_ATMSVC_SOCKET; | |
1270 | case PF_RDS: | |
1271 | return SECCLASS_RDS_SOCKET; | |
1272 | case PF_IRDA: | |
1273 | return SECCLASS_IRDA_SOCKET; | |
1274 | case PF_PPPOX: | |
1275 | return SECCLASS_PPPOX_SOCKET; | |
1276 | case PF_LLC: | |
1277 | return SECCLASS_LLC_SOCKET; | |
da69a530 SS |
1278 | case PF_CAN: |
1279 | return SECCLASS_CAN_SOCKET; | |
1280 | case PF_TIPC: | |
1281 | return SECCLASS_TIPC_SOCKET; | |
1282 | case PF_BLUETOOTH: | |
1283 | return SECCLASS_BLUETOOTH_SOCKET; | |
1284 | case PF_IUCV: | |
1285 | return SECCLASS_IUCV_SOCKET; | |
1286 | case PF_RXRPC: | |
1287 | return SECCLASS_RXRPC_SOCKET; | |
1288 | case PF_ISDN: | |
1289 | return SECCLASS_ISDN_SOCKET; | |
1290 | case PF_PHONET: | |
1291 | return SECCLASS_PHONET_SOCKET; | |
1292 | case PF_IEEE802154: | |
1293 | return SECCLASS_IEEE802154_SOCKET; | |
1294 | case PF_CAIF: | |
1295 | return SECCLASS_CAIF_SOCKET; | |
1296 | case PF_ALG: | |
1297 | return SECCLASS_ALG_SOCKET; | |
1298 | case PF_NFC: | |
1299 | return SECCLASS_NFC_SOCKET; | |
1300 | case PF_VSOCK: | |
1301 | return SECCLASS_VSOCK_SOCKET; | |
1302 | case PF_KCM: | |
1303 | return SECCLASS_KCM_SOCKET; | |
1304 | case PF_QIPCRTR: | |
1305 | return SECCLASS_QIPCRTR_SOCKET; | |
3051bf36 LT |
1306 | case PF_SMC: |
1307 | return SECCLASS_SMC_SOCKET; | |
68e8b849 BT |
1308 | case PF_XDP: |
1309 | return SECCLASS_XDP_SOCKET; | |
1310 | #if PF_MAX > 45 | |
da69a530 SS |
1311 | #error New address family defined, please update this function. |
1312 | #endif | |
1313 | } | |
1314 | } | |
1315 | ||
1da177e4 LT |
1316 | return SECCLASS_SOCKET; |
1317 | } | |
1318 | ||
134509d5 SS |
1319 | static int selinux_genfs_get_sid(struct dentry *dentry, |
1320 | u16 tclass, | |
1321 | u16 flags, | |
1322 | u32 *sid) | |
1da177e4 | 1323 | { |
8e6c9693 | 1324 | int rc; |
fc64005c | 1325 | struct super_block *sb = dentry->d_sb; |
8e6c9693 | 1326 | char *buffer, *path; |
1da177e4 | 1327 | |
828dfe1d | 1328 | buffer = (char *)__get_free_page(GFP_KERNEL); |
1da177e4 LT |
1329 | if (!buffer) |
1330 | return -ENOMEM; | |
1331 | ||
8e6c9693 LAG |
1332 | path = dentry_path_raw(dentry, buffer, PAGE_SIZE); |
1333 | if (IS_ERR(path)) | |
1334 | rc = PTR_ERR(path); | |
1335 | else { | |
134509d5 SS |
1336 | if (flags & SE_SBPROC) { |
1337 | /* each process gets a /proc/PID/ entry. Strip off the | |
1338 | * PID part to get a valid selinux labeling. | |
1339 | * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ | |
1340 | while (path[1] >= '0' && path[1] <= '9') { | |
1341 | path[1] = '/'; | |
1342 | path++; | |
1343 | } | |
8e6c9693 | 1344 | } |
aa8e712c SS |
1345 | rc = security_genfs_sid(&selinux_state, sb->s_type->name, |
1346 | path, tclass, sid); | |
7bb185ed SS |
1347 | if (rc == -ENOENT) { |
1348 | /* No match in policy, mark as unlabeled. */ | |
1349 | *sid = SECINITSID_UNLABELED; | |
1350 | rc = 0; | |
1351 | } | |
1da177e4 | 1352 | } |
1da177e4 LT |
1353 | free_page((unsigned long)buffer); |
1354 | return rc; | |
1355 | } | |
1da177e4 LT |
1356 | |
1357 | /* The inode's security attributes must be initialized before first use. */ | |
1358 | static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) | |
1359 | { | |
1360 | struct superblock_security_struct *sbsec = NULL; | |
80788c22 | 1361 | struct inode_security_struct *isec = selinux_inode(inode); |
9287aed2 AG |
1362 | u32 task_sid, sid = 0; |
1363 | u16 sclass; | |
1da177e4 LT |
1364 | struct dentry *dentry; |
1365 | #define INITCONTEXTLEN 255 | |
1366 | char *context = NULL; | |
1367 | unsigned len = 0; | |
1368 | int rc = 0; | |
1da177e4 | 1369 | |
6f3be9f5 | 1370 | if (isec->initialized == LABEL_INITIALIZED) |
13457d07 | 1371 | return 0; |
1da177e4 | 1372 | |
9287aed2 | 1373 | spin_lock(&isec->lock); |
6f3be9f5 | 1374 | if (isec->initialized == LABEL_INITIALIZED) |
23970741 | 1375 | goto out_unlock; |
1da177e4 | 1376 | |
13457d07 AG |
1377 | if (isec->sclass == SECCLASS_FILE) |
1378 | isec->sclass = inode_mode_to_security_class(inode->i_mode); | |
1379 | ||
1da177e4 | 1380 | sbsec = inode->i_sb->s_security; |
0d90a7ec | 1381 | if (!(sbsec->flags & SE_SBINITIALIZED)) { |
1da177e4 LT |
1382 | /* Defer initialization until selinux_complete_init, |
1383 | after the initial policy is loaded and the security | |
1384 | server is ready to handle calls. */ | |
1385 | spin_lock(&sbsec->isec_lock); | |
1386 | if (list_empty(&isec->list)) | |
1387 | list_add(&isec->list, &sbsec->isec_head); | |
1388 | spin_unlock(&sbsec->isec_lock); | |
23970741 | 1389 | goto out_unlock; |
1da177e4 LT |
1390 | } |
1391 | ||
9287aed2 AG |
1392 | sclass = isec->sclass; |
1393 | task_sid = isec->task_sid; | |
1394 | sid = isec->sid; | |
1395 | isec->initialized = LABEL_PENDING; | |
1396 | spin_unlock(&isec->lock); | |
1397 | ||
1da177e4 | 1398 | switch (sbsec->behavior) { |
eb9ae686 DQ |
1399 | case SECURITY_FS_USE_NATIVE: |
1400 | break; | |
1da177e4 | 1401 | case SECURITY_FS_USE_XATTR: |
5d6c3191 | 1402 | if (!(inode->i_opflags & IOP_XATTR)) { |
9287aed2 | 1403 | sid = sbsec->def_sid; |
1da177e4 LT |
1404 | break; |
1405 | } | |
1da177e4 LT |
1406 | /* Need a dentry, since the xattr API requires one. |
1407 | Life would be simpler if we could just pass the inode. */ | |
1408 | if (opt_dentry) { | |
1409 | /* Called from d_instantiate or d_splice_alias. */ | |
1410 | dentry = dget(opt_dentry); | |
1411 | } else { | |
b127125d AV |
1412 | /* |
1413 | * Called from selinux_complete_init, try to find a dentry. | |
1414 | * Some filesystems really want a connected one, so try | |
1415 | * that first. We could split SECURITY_FS_USE_XATTR in | |
1416 | * two, depending upon that... | |
1417 | */ | |
1da177e4 | 1418 | dentry = d_find_alias(inode); |
b127125d AV |
1419 | if (!dentry) |
1420 | dentry = d_find_any_alias(inode); | |
1da177e4 LT |
1421 | } |
1422 | if (!dentry) { | |
df7f54c0 EP |
1423 | /* |
1424 | * this is can be hit on boot when a file is accessed | |
1425 | * before the policy is loaded. When we load policy we | |
1426 | * may find inodes that have no dentry on the | |
1427 | * sbsec->isec_head list. No reason to complain as these | |
1428 | * will get fixed up the next time we go through | |
1429 | * inode_doinit with a dentry, before these inodes could | |
1430 | * be used again by userspace. | |
1431 | */ | |
9287aed2 | 1432 | goto out; |
1da177e4 LT |
1433 | } |
1434 | ||
1435 | len = INITCONTEXTLEN; | |
4cb912f1 | 1436 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1437 | if (!context) { |
1438 | rc = -ENOMEM; | |
1439 | dput(dentry); | |
9287aed2 | 1440 | goto out; |
1da177e4 | 1441 | } |
4cb912f1 | 1442 | context[len] = '\0'; |
5d6c3191 | 1443 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 | 1444 | if (rc == -ERANGE) { |
314dabb8 JM |
1445 | kfree(context); |
1446 | ||
1da177e4 | 1447 | /* Need a larger buffer. Query for the right size. */ |
5d6c3191 | 1448 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0); |
1da177e4 LT |
1449 | if (rc < 0) { |
1450 | dput(dentry); | |
9287aed2 | 1451 | goto out; |
1da177e4 | 1452 | } |
1da177e4 | 1453 | len = rc; |
4cb912f1 | 1454 | context = kmalloc(len+1, GFP_NOFS); |
1da177e4 LT |
1455 | if (!context) { |
1456 | rc = -ENOMEM; | |
1457 | dput(dentry); | |
9287aed2 | 1458 | goto out; |
1da177e4 | 1459 | } |
4cb912f1 | 1460 | context[len] = '\0'; |
5d6c3191 | 1461 | rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len); |
1da177e4 LT |
1462 | } |
1463 | dput(dentry); | |
1464 | if (rc < 0) { | |
1465 | if (rc != -ENODATA) { | |
c103a91e | 1466 | pr_warn("SELinux: %s: getxattr returned " |
dd6f953a | 1467 | "%d for dev=%s ino=%ld\n", __func__, |
1da177e4 LT |
1468 | -rc, inode->i_sb->s_id, inode->i_ino); |
1469 | kfree(context); | |
9287aed2 | 1470 | goto out; |
1da177e4 LT |
1471 | } |
1472 | /* Map ENODATA to the default file SID */ | |
1473 | sid = sbsec->def_sid; | |
1474 | rc = 0; | |
1475 | } else { | |
aa8e712c SS |
1476 | rc = security_context_to_sid_default(&selinux_state, |
1477 | context, rc, &sid, | |
869ab514 SS |
1478 | sbsec->def_sid, |
1479 | GFP_NOFS); | |
1da177e4 | 1480 | if (rc) { |
4ba0a8ad EP |
1481 | char *dev = inode->i_sb->s_id; |
1482 | unsigned long ino = inode->i_ino; | |
1483 | ||
1484 | if (rc == -EINVAL) { | |
1485 | if (printk_ratelimit()) | |
c103a91e | 1486 | pr_notice("SELinux: inode=%lu on dev=%s was found to have an invalid " |
4ba0a8ad EP |
1487 | "context=%s. This indicates you may need to relabel the inode or the " |
1488 | "filesystem in question.\n", ino, dev, context); | |
1489 | } else { | |
c103a91e | 1490 | pr_warn("SELinux: %s: context_to_sid(%s) " |
4ba0a8ad EP |
1491 | "returned %d for dev=%s ino=%ld\n", |
1492 | __func__, context, -rc, dev, ino); | |
1493 | } | |
1da177e4 LT |
1494 | kfree(context); |
1495 | /* Leave with the unlabeled SID */ | |
1496 | rc = 0; | |
1497 | break; | |
1498 | } | |
1499 | } | |
1500 | kfree(context); | |
1da177e4 LT |
1501 | break; |
1502 | case SECURITY_FS_USE_TASK: | |
9287aed2 | 1503 | sid = task_sid; |
1da177e4 LT |
1504 | break; |
1505 | case SECURITY_FS_USE_TRANS: | |
1506 | /* Default to the fs SID. */ | |
9287aed2 | 1507 | sid = sbsec->sid; |
1da177e4 LT |
1508 | |
1509 | /* Try to obtain a transition SID. */ | |
aa8e712c SS |
1510 | rc = security_transition_sid(&selinux_state, task_sid, sid, |
1511 | sclass, NULL, &sid); | |
1da177e4 | 1512 | if (rc) |
9287aed2 | 1513 | goto out; |
1da177e4 | 1514 | break; |
c312feb2 | 1515 | case SECURITY_FS_USE_MNTPOINT: |
9287aed2 | 1516 | sid = sbsec->mntpoint_sid; |
c312feb2 | 1517 | break; |
1da177e4 | 1518 | default: |
c312feb2 | 1519 | /* Default to the fs superblock SID. */ |
9287aed2 | 1520 | sid = sbsec->sid; |
1da177e4 | 1521 | |
134509d5 | 1522 | if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) { |
f64410ec PM |
1523 | /* We must have a dentry to determine the label on |
1524 | * procfs inodes */ | |
b127125d | 1525 | if (opt_dentry) { |
f64410ec PM |
1526 | /* Called from d_instantiate or |
1527 | * d_splice_alias. */ | |
1528 | dentry = dget(opt_dentry); | |
b127125d | 1529 | } else { |
f64410ec | 1530 | /* Called from selinux_complete_init, try to |
b127125d AV |
1531 | * find a dentry. Some filesystems really want |
1532 | * a connected one, so try that first. | |
1533 | */ | |
f64410ec | 1534 | dentry = d_find_alias(inode); |
b127125d AV |
1535 | if (!dentry) |
1536 | dentry = d_find_any_alias(inode); | |
1537 | } | |
f64410ec PM |
1538 | /* |
1539 | * This can be hit on boot when a file is accessed | |
1540 | * before the policy is loaded. When we load policy we | |
1541 | * may find inodes that have no dentry on the | |
1542 | * sbsec->isec_head list. No reason to complain as | |
1543 | * these will get fixed up the next time we go through | |
1544 | * inode_doinit() with a dentry, before these inodes | |
1545 | * could be used again by userspace. | |
1546 | */ | |
1547 | if (!dentry) | |
9287aed2 AG |
1548 | goto out; |
1549 | rc = selinux_genfs_get_sid(dentry, sclass, | |
134509d5 | 1550 | sbsec->flags, &sid); |
f64410ec PM |
1551 | dput(dentry); |
1552 | if (rc) | |
9287aed2 | 1553 | goto out; |
1da177e4 LT |
1554 | } |
1555 | break; | |
1556 | } | |
1557 | ||
9287aed2 AG |
1558 | out: |
1559 | spin_lock(&isec->lock); | |
1560 | if (isec->initialized == LABEL_PENDING) { | |
1561 | if (!sid || rc) { | |
1562 | isec->initialized = LABEL_INVALID; | |
1563 | goto out_unlock; | |
1564 | } | |
1565 | ||
1566 | isec->initialized = LABEL_INITIALIZED; | |
1567 | isec->sid = sid; | |
1568 | } | |
1da177e4 | 1569 | |
23970741 | 1570 | out_unlock: |
9287aed2 | 1571 | spin_unlock(&isec->lock); |
1da177e4 LT |
1572 | return rc; |
1573 | } | |
1574 | ||
1575 | /* Convert a Linux signal to an access vector. */ | |
1576 | static inline u32 signal_to_av(int sig) | |
1577 | { | |
1578 | u32 perm = 0; | |
1579 | ||
1580 | switch (sig) { | |
1581 | case SIGCHLD: | |
1582 | /* Commonly granted from child to parent. */ | |
1583 | perm = PROCESS__SIGCHLD; | |
1584 | break; | |
1585 | case SIGKILL: | |
1586 | /* Cannot be caught or ignored */ | |
1587 | perm = PROCESS__SIGKILL; | |
1588 | break; | |
1589 | case SIGSTOP: | |
1590 | /* Cannot be caught or ignored */ | |
1591 | perm = PROCESS__SIGSTOP; | |
1592 | break; | |
1593 | default: | |
1594 | /* All other signals. */ | |
1595 | perm = PROCESS__SIGNAL; | |
1596 | break; | |
1597 | } | |
1598 | ||
1599 | return perm; | |
1600 | } | |
1601 | ||
b68e418c SS |
1602 | #if CAP_LAST_CAP > 63 |
1603 | #error Fix SELinux to handle capabilities > 63. | |
1604 | #endif | |
1605 | ||
1da177e4 | 1606 | /* Check whether a task is allowed to use a capability. */ |
6a9de491 | 1607 | static int cred_has_capability(const struct cred *cred, |
c1a85a00 | 1608 | int cap, unsigned int opts, bool initns) |
1da177e4 | 1609 | { |
2bf49690 | 1610 | struct common_audit_data ad; |
06112163 | 1611 | struct av_decision avd; |
b68e418c | 1612 | u16 sclass; |
3699c53c | 1613 | u32 sid = cred_sid(cred); |
b68e418c | 1614 | u32 av = CAP_TO_MASK(cap); |
06112163 | 1615 | int rc; |
1da177e4 | 1616 | |
50c205f5 | 1617 | ad.type = LSM_AUDIT_DATA_CAP; |
1da177e4 LT |
1618 | ad.u.cap = cap; |
1619 | ||
b68e418c SS |
1620 | switch (CAP_TO_INDEX(cap)) { |
1621 | case 0: | |
8e4ff6f2 | 1622 | sclass = initns ? SECCLASS_CAPABILITY : SECCLASS_CAP_USERNS; |
b68e418c SS |
1623 | break; |
1624 | case 1: | |
8e4ff6f2 | 1625 | sclass = initns ? SECCLASS_CAPABILITY2 : SECCLASS_CAP2_USERNS; |
b68e418c SS |
1626 | break; |
1627 | default: | |
c103a91e | 1628 | pr_err("SELinux: out of range capability %d\n", cap); |
b68e418c | 1629 | BUG(); |
a35c6c83 | 1630 | return -EINVAL; |
b68e418c | 1631 | } |
06112163 | 1632 | |
6b6bc620 SS |
1633 | rc = avc_has_perm_noaudit(&selinux_state, |
1634 | sid, sid, sclass, av, 0, &avd); | |
c1a85a00 | 1635 | if (!(opts & CAP_OPT_NOAUDIT)) { |
6b6bc620 SS |
1636 | int rc2 = avc_audit(&selinux_state, |
1637 | sid, sid, sclass, av, &avd, rc, &ad, 0); | |
9ade0cf4 EP |
1638 | if (rc2) |
1639 | return rc2; | |
1640 | } | |
06112163 | 1641 | return rc; |
1da177e4 LT |
1642 | } |
1643 | ||
1da177e4 LT |
1644 | /* Check whether a task has a particular permission to an inode. |
1645 | The 'adp' parameter is optional and allows other audit | |
1646 | data to be passed (e.g. the dentry). */ | |
88e67f3b | 1647 | static int inode_has_perm(const struct cred *cred, |
1da177e4 LT |
1648 | struct inode *inode, |
1649 | u32 perms, | |
19e49834 | 1650 | struct common_audit_data *adp) |
1da177e4 | 1651 | { |
1da177e4 | 1652 | struct inode_security_struct *isec; |
275bb41e | 1653 | u32 sid; |
1da177e4 | 1654 | |
e0e81739 DH |
1655 | validate_creds(cred); |
1656 | ||
828dfe1d | 1657 | if (unlikely(IS_PRIVATE(inode))) |
bbaca6c2 SS |
1658 | return 0; |
1659 | ||
88e67f3b | 1660 | sid = cred_sid(cred); |
80788c22 | 1661 | isec = selinux_inode(inode); |
1da177e4 | 1662 | |
6b6bc620 SS |
1663 | return avc_has_perm(&selinux_state, |
1664 | sid, isec->sid, isec->sclass, perms, adp); | |
1da177e4 LT |
1665 | } |
1666 | ||
1667 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1668 | the dentry to help the auditing code to more easily generate the | |
1669 | pathname if needed. */ | |
88e67f3b | 1670 | static inline int dentry_has_perm(const struct cred *cred, |
1da177e4 LT |
1671 | struct dentry *dentry, |
1672 | u32 av) | |
1673 | { | |
c6f493d6 | 1674 | struct inode *inode = d_backing_inode(dentry); |
2bf49690 | 1675 | struct common_audit_data ad; |
88e67f3b | 1676 | |
50c205f5 | 1677 | ad.type = LSM_AUDIT_DATA_DENTRY; |
2875fa00 | 1678 | ad.u.dentry = dentry; |
5d226df4 | 1679 | __inode_security_revalidate(inode, dentry, true); |
19e49834 | 1680 | return inode_has_perm(cred, inode, av, &ad); |
2875fa00 EP |
1681 | } |
1682 | ||
1683 | /* Same as inode_has_perm, but pass explicit audit data containing | |
1684 | the path to help the auditing code to more easily generate the | |
1685 | pathname if needed. */ | |
1686 | static inline int path_has_perm(const struct cred *cred, | |
3f7036a0 | 1687 | const struct path *path, |
2875fa00 EP |
1688 | u32 av) |
1689 | { | |
c6f493d6 | 1690 | struct inode *inode = d_backing_inode(path->dentry); |
2875fa00 EP |
1691 | struct common_audit_data ad; |
1692 | ||
50c205f5 | 1693 | ad.type = LSM_AUDIT_DATA_PATH; |
2875fa00 | 1694 | ad.u.path = *path; |
5d226df4 | 1695 | __inode_security_revalidate(inode, path->dentry, true); |
19e49834 | 1696 | return inode_has_perm(cred, inode, av, &ad); |
1da177e4 LT |
1697 | } |
1698 | ||
13f8e981 DH |
1699 | /* Same as path_has_perm, but uses the inode from the file struct. */ |
1700 | static inline int file_path_has_perm(const struct cred *cred, | |
1701 | struct file *file, | |
1702 | u32 av) | |
1703 | { | |
1704 | struct common_audit_data ad; | |
1705 | ||
43af5de7 VG |
1706 | ad.type = LSM_AUDIT_DATA_FILE; |
1707 | ad.u.file = file; | |
19e49834 | 1708 | return inode_has_perm(cred, file_inode(file), av, &ad); |
13f8e981 DH |
1709 | } |
1710 | ||
f66e448c CF |
1711 | #ifdef CONFIG_BPF_SYSCALL |
1712 | static int bpf_fd_pass(struct file *file, u32 sid); | |
1713 | #endif | |
1714 | ||
1da177e4 LT |
1715 | /* Check whether a task can use an open file descriptor to |
1716 | access an inode in a given way. Check access to the | |
1717 | descriptor itself, and then use dentry_has_perm to | |
1718 | check a particular permission to the file. | |
1719 | Access to the descriptor is implicitly granted if it | |
1720 | has the same SID as the process. If av is zero, then | |
1721 | access to the file is not checked, e.g. for cases | |
1722 | where only the descriptor is affected like seek. */ | |
88e67f3b DH |
1723 | static int file_has_perm(const struct cred *cred, |
1724 | struct file *file, | |
1725 | u32 av) | |
1da177e4 | 1726 | { |
bb6c6b02 | 1727 | struct file_security_struct *fsec = selinux_file(file); |
496ad9aa | 1728 | struct inode *inode = file_inode(file); |
2bf49690 | 1729 | struct common_audit_data ad; |
88e67f3b | 1730 | u32 sid = cred_sid(cred); |
1da177e4 LT |
1731 | int rc; |
1732 | ||
43af5de7 VG |
1733 | ad.type = LSM_AUDIT_DATA_FILE; |
1734 | ad.u.file = file; | |
1da177e4 | 1735 | |
275bb41e | 1736 | if (sid != fsec->sid) { |
6b6bc620 SS |
1737 | rc = avc_has_perm(&selinux_state, |
1738 | sid, fsec->sid, | |
1da177e4 LT |
1739 | SECCLASS_FD, |
1740 | FD__USE, | |
1741 | &ad); | |
1742 | if (rc) | |
88e67f3b | 1743 | goto out; |
1da177e4 LT |
1744 | } |
1745 | ||
f66e448c CF |
1746 | #ifdef CONFIG_BPF_SYSCALL |
1747 | rc = bpf_fd_pass(file, cred_sid(cred)); | |
1748 | if (rc) | |
1749 | return rc; | |
1750 | #endif | |
1751 | ||
1da177e4 | 1752 | /* av is zero if only checking access to the descriptor. */ |
88e67f3b | 1753 | rc = 0; |
1da177e4 | 1754 | if (av) |
19e49834 | 1755 | rc = inode_has_perm(cred, inode, av, &ad); |
1da177e4 | 1756 | |
88e67f3b DH |
1757 | out: |
1758 | return rc; | |
1da177e4 LT |
1759 | } |
1760 | ||
c3c188b2 DH |
1761 | /* |
1762 | * Determine the label for an inode that might be unioned. | |
1763 | */ | |
c957f6df VG |
1764 | static int |
1765 | selinux_determine_inode_label(const struct task_security_struct *tsec, | |
1766 | struct inode *dir, | |
1767 | const struct qstr *name, u16 tclass, | |
1768 | u32 *_new_isid) | |
c3c188b2 DH |
1769 | { |
1770 | const struct superblock_security_struct *sbsec = dir->i_sb->s_security; | |
c3c188b2 DH |
1771 | |
1772 | if ((sbsec->flags & SE_SBINITIALIZED) && | |
1773 | (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) { | |
1774 | *_new_isid = sbsec->mntpoint_sid; | |
1775 | } else if ((sbsec->flags & SBLABEL_MNT) && | |
1776 | tsec->create_sid) { | |
1777 | *_new_isid = tsec->create_sid; | |
1778 | } else { | |
20cdef8d | 1779 | const struct inode_security_struct *dsec = inode_security(dir); |
aa8e712c SS |
1780 | return security_transition_sid(&selinux_state, tsec->sid, |
1781 | dsec->sid, tclass, | |
c3c188b2 DH |
1782 | name, _new_isid); |
1783 | } | |
1784 | ||
1785 | return 0; | |
1786 | } | |
1787 | ||
1da177e4 LT |
1788 | /* Check whether a task can create a file. */ |
1789 | static int may_create(struct inode *dir, | |
1790 | struct dentry *dentry, | |
1791 | u16 tclass) | |
1792 | { | |
0c6cfa62 | 1793 | const struct task_security_struct *tsec = selinux_cred(current_cred()); |
1da177e4 LT |
1794 | struct inode_security_struct *dsec; |
1795 | struct superblock_security_struct *sbsec; | |
275bb41e | 1796 | u32 sid, newsid; |
2bf49690 | 1797 | struct common_audit_data ad; |
1da177e4 LT |
1798 | int rc; |
1799 | ||
83da53c5 | 1800 | dsec = inode_security(dir); |
1da177e4 LT |
1801 | sbsec = dir->i_sb->s_security; |
1802 | ||
275bb41e | 1803 | sid = tsec->sid; |
275bb41e | 1804 | |
50c205f5 | 1805 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1806 | ad.u.dentry = dentry; |
1da177e4 | 1807 | |
6b6bc620 SS |
1808 | rc = avc_has_perm(&selinux_state, |
1809 | sid, dsec->sid, SECCLASS_DIR, | |
1da177e4 LT |
1810 | DIR__ADD_NAME | DIR__SEARCH, |
1811 | &ad); | |
1812 | if (rc) | |
1813 | return rc; | |
1814 | ||
0c6cfa62 | 1815 | rc = selinux_determine_inode_label(selinux_cred(current_cred()), dir, |
c957f6df | 1816 | &dentry->d_name, tclass, &newsid); |
c3c188b2 DH |
1817 | if (rc) |
1818 | return rc; | |
1da177e4 | 1819 | |
6b6bc620 SS |
1820 | rc = avc_has_perm(&selinux_state, |
1821 | sid, newsid, tclass, FILE__CREATE, &ad); | |
1da177e4 LT |
1822 | if (rc) |
1823 | return rc; | |
1824 | ||
6b6bc620 SS |
1825 | return avc_has_perm(&selinux_state, |
1826 | newsid, sbsec->sid, | |
1da177e4 LT |
1827 | SECCLASS_FILESYSTEM, |
1828 | FILESYSTEM__ASSOCIATE, &ad); | |
1829 | } | |
1830 | ||
828dfe1d EP |
1831 | #define MAY_LINK 0 |
1832 | #define MAY_UNLINK 1 | |
1833 | #define MAY_RMDIR 2 | |
1da177e4 LT |
1834 | |
1835 | /* Check whether a task can link, unlink, or rmdir a file/directory. */ | |
1836 | static int may_link(struct inode *dir, | |
1837 | struct dentry *dentry, | |
1838 | int kind) | |
1839 | ||
1840 | { | |
1da177e4 | 1841 | struct inode_security_struct *dsec, *isec; |
2bf49690 | 1842 | struct common_audit_data ad; |
275bb41e | 1843 | u32 sid = current_sid(); |
1da177e4 LT |
1844 | u32 av; |
1845 | int rc; | |
1846 | ||
83da53c5 AG |
1847 | dsec = inode_security(dir); |
1848 | isec = backing_inode_security(dentry); | |
1da177e4 | 1849 | |
50c205f5 | 1850 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 1851 | ad.u.dentry = dentry; |
1da177e4 LT |
1852 | |
1853 | av = DIR__SEARCH; | |
1854 | av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); | |
6b6bc620 SS |
1855 | rc = avc_has_perm(&selinux_state, |
1856 | sid, dsec->sid, SECCLASS_DIR, av, &ad); | |
1da177e4 LT |
1857 | if (rc) |
1858 | return rc; | |
1859 | ||
1860 | switch (kind) { | |
1861 | case MAY_LINK: | |
1862 | av = FILE__LINK; | |
1863 | break; | |
1864 | case MAY_UNLINK: | |
1865 | av = FILE__UNLINK; | |
1866 | break; | |
1867 | case MAY_RMDIR: | |
1868 | av = DIR__RMDIR; | |
1869 | break; | |
1870 | default: | |
c103a91e | 1871 | pr_warn("SELinux: %s: unrecognized kind %d\n", |
744ba35e | 1872 | __func__, kind); |
1da177e4 LT |
1873 | return 0; |
1874 | } | |
1875 | ||
6b6bc620 SS |
1876 | rc = avc_has_perm(&selinux_state, |
1877 | sid, isec->sid, isec->sclass, av, &ad); | |
1da177e4 LT |
1878 | return rc; |
1879 | } | |
1880 | ||
1881 | static inline int may_rename(struct inode *old_dir, | |
1882 | struct dentry *old_dentry, | |
1883 | struct inode *new_dir, | |
1884 | struct dentry *new_dentry) | |
1885 | { | |
1da177e4 | 1886 | struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; |
2bf49690 | 1887 | struct common_audit_data ad; |
275bb41e | 1888 | u32 sid = current_sid(); |
1da177e4 LT |
1889 | u32 av; |
1890 | int old_is_dir, new_is_dir; | |
1891 | int rc; | |
1892 | ||
83da53c5 AG |
1893 | old_dsec = inode_security(old_dir); |
1894 | old_isec = backing_inode_security(old_dentry); | |
e36cb0b8 | 1895 | old_is_dir = d_is_dir(old_dentry); |
83da53c5 | 1896 | new_dsec = inode_security(new_dir); |
1da177e4 | 1897 | |
50c205f5 | 1898 | ad.type = LSM_AUDIT_DATA_DENTRY; |
1da177e4 | 1899 | |
a269434d | 1900 | ad.u.dentry = old_dentry; |
6b6bc620 SS |
1901 | rc = avc_has_perm(&selinux_state, |
1902 | sid, old_dsec->sid, SECCLASS_DIR, | |
1da177e4 LT |
1903 | DIR__REMOVE_NAME | DIR__SEARCH, &ad); |
1904 | if (rc) | |
1905 | return rc; | |
6b6bc620 SS |
1906 | rc = avc_has_perm(&selinux_state, |
1907 | sid, old_isec->sid, | |
1da177e4 LT |
1908 | old_isec->sclass, FILE__RENAME, &ad); |
1909 | if (rc) | |
1910 | return rc; | |
1911 | if (old_is_dir && new_dir != old_dir) { | |
6b6bc620 SS |
1912 | rc = avc_has_perm(&selinux_state, |
1913 | sid, old_isec->sid, | |
1da177e4 LT |
1914 | old_isec->sclass, DIR__REPARENT, &ad); |
1915 | if (rc) | |
1916 | return rc; | |
1917 | } | |
1918 | ||
a269434d | 1919 | ad.u.dentry = new_dentry; |
1da177e4 | 1920 | av = DIR__ADD_NAME | DIR__SEARCH; |
2c616d4d | 1921 | if (d_is_positive(new_dentry)) |
1da177e4 | 1922 | av |= DIR__REMOVE_NAME; |
6b6bc620 SS |
1923 | rc = avc_has_perm(&selinux_state, |
1924 | sid, new_dsec->sid, SECCLASS_DIR, av, &ad); | |
1da177e4 LT |
1925 | if (rc) |
1926 | return rc; | |
2c616d4d | 1927 | if (d_is_positive(new_dentry)) { |
83da53c5 | 1928 | new_isec = backing_inode_security(new_dentry); |
e36cb0b8 | 1929 | new_is_dir = d_is_dir(new_dentry); |
6b6bc620 SS |
1930 | rc = avc_has_perm(&selinux_state, |
1931 | sid, new_isec->sid, | |
1da177e4 LT |
1932 | new_isec->sclass, |
1933 | (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); | |
1934 | if (rc) | |
1935 | return rc; | |
1936 | } | |
1937 | ||
1938 | return 0; | |
1939 | } | |
1940 | ||
1941 | /* Check whether a task can perform a filesystem operation. */ | |
88e67f3b | 1942 | static int superblock_has_perm(const struct cred *cred, |
1da177e4 LT |
1943 | struct super_block *sb, |
1944 | u32 perms, | |
2bf49690 | 1945 | struct common_audit_data *ad) |
1da177e4 | 1946 | { |
1da177e4 | 1947 | struct superblock_security_struct *sbsec; |
88e67f3b | 1948 | u32 sid = cred_sid(cred); |
1da177e4 | 1949 | |
1da177e4 | 1950 | sbsec = sb->s_security; |
6b6bc620 SS |
1951 | return avc_has_perm(&selinux_state, |
1952 | sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); | |
1da177e4 LT |
1953 | } |
1954 | ||
1955 | /* Convert a Linux mode and permission mask to an access vector. */ | |
1956 | static inline u32 file_mask_to_av(int mode, int mask) | |
1957 | { | |
1958 | u32 av = 0; | |
1959 | ||
dba19c60 | 1960 | if (!S_ISDIR(mode)) { |
1da177e4 LT |
1961 | if (mask & MAY_EXEC) |
1962 | av |= FILE__EXECUTE; | |
1963 | if (mask & MAY_READ) | |
1964 | av |= FILE__READ; | |
1965 | ||
1966 | if (mask & MAY_APPEND) | |
1967 | av |= FILE__APPEND; | |
1968 | else if (mask & MAY_WRITE) | |
1969 | av |= FILE__WRITE; | |
1970 | ||
1971 | } else { | |
1972 | if (mask & MAY_EXEC) | |
1973 | av |= DIR__SEARCH; | |
1974 | if (mask & MAY_WRITE) | |
1975 | av |= DIR__WRITE; | |
1976 | if (mask & MAY_READ) | |
1977 | av |= DIR__READ; | |
1978 | } | |
1979 | ||
1980 | return av; | |
1981 | } | |
1982 | ||
8b6a5a37 EP |
1983 | /* Convert a Linux file to an access vector. */ |
1984 | static inline u32 file_to_av(struct file *file) | |
1985 | { | |
1986 | u32 av = 0; | |
1987 | ||
1988 | if (file->f_mode & FMODE_READ) | |
1989 | av |= FILE__READ; | |
1990 | if (file->f_mode & FMODE_WRITE) { | |
1991 | if (file->f_flags & O_APPEND) | |
1992 | av |= FILE__APPEND; | |
1993 | else | |
1994 | av |= FILE__WRITE; | |
1995 | } | |
1996 | if (!av) { | |
1997 | /* | |
1998 | * Special file opened with flags 3 for ioctl-only use. | |
1999 | */ | |
2000 | av = FILE__IOCTL; | |
2001 | } | |
2002 | ||
2003 | return av; | |
2004 | } | |
2005 | ||
b0c636b9 | 2006 | /* |
8b6a5a37 | 2007 | * Convert a file to an access vector and include the correct open |
b0c636b9 EP |
2008 | * open permission. |
2009 | */ | |
8b6a5a37 | 2010 | static inline u32 open_file_to_av(struct file *file) |
b0c636b9 | 2011 | { |
8b6a5a37 | 2012 | u32 av = file_to_av(file); |
ccb54478 | 2013 | struct inode *inode = file_inode(file); |
b0c636b9 | 2014 | |
aa8e712c SS |
2015 | if (selinux_policycap_openperm() && |
2016 | inode->i_sb->s_magic != SOCKFS_MAGIC) | |
49b7b8de EP |
2017 | av |= FILE__OPEN; |
2018 | ||
b0c636b9 EP |
2019 | return av; |
2020 | } | |
2021 | ||
1da177e4 LT |
2022 | /* Hook functions begin here. */ |
2023 | ||
79af7307 SS |
2024 | static int selinux_binder_set_context_mgr(struct task_struct *mgr) |
2025 | { | |
2026 | u32 mysid = current_sid(); | |
2027 | u32 mgrsid = task_sid(mgr); | |
2028 | ||
6b6bc620 SS |
2029 | return avc_has_perm(&selinux_state, |
2030 | mysid, mgrsid, SECCLASS_BINDER, | |
79af7307 SS |
2031 | BINDER__SET_CONTEXT_MGR, NULL); |
2032 | } | |
2033 | ||
2034 | static int selinux_binder_transaction(struct task_struct *from, | |
2035 | struct task_struct *to) | |
2036 | { | |
2037 | u32 mysid = current_sid(); | |
2038 | u32 fromsid = task_sid(from); | |
2039 | u32 tosid = task_sid(to); | |
2040 | int rc; | |
2041 | ||
2042 | if (mysid != fromsid) { | |
6b6bc620 SS |
2043 | rc = avc_has_perm(&selinux_state, |
2044 | mysid, fromsid, SECCLASS_BINDER, | |
79af7307 SS |
2045 | BINDER__IMPERSONATE, NULL); |
2046 | if (rc) | |
2047 | return rc; | |
2048 | } | |
2049 | ||
6b6bc620 SS |
2050 | return avc_has_perm(&selinux_state, |
2051 | fromsid, tosid, SECCLASS_BINDER, BINDER__CALL, | |
79af7307 SS |
2052 | NULL); |
2053 | } | |
2054 | ||
2055 | static int selinux_binder_transfer_binder(struct task_struct *from, | |
2056 | struct task_struct *to) | |
2057 | { | |
2058 | u32 fromsid = task_sid(from); | |
2059 | u32 tosid = task_sid(to); | |
2060 | ||
6b6bc620 SS |
2061 | return avc_has_perm(&selinux_state, |
2062 | fromsid, tosid, SECCLASS_BINDER, BINDER__TRANSFER, | |
79af7307 SS |
2063 | NULL); |
2064 | } | |
2065 | ||
2066 | static int selinux_binder_transfer_file(struct task_struct *from, | |
2067 | struct task_struct *to, | |
2068 | struct file *file) | |
2069 | { | |
2070 | u32 sid = task_sid(to); | |
bb6c6b02 | 2071 | struct file_security_struct *fsec = selinux_file(file); |
83da53c5 | 2072 | struct dentry *dentry = file->f_path.dentry; |
20cdef8d | 2073 | struct inode_security_struct *isec; |
79af7307 SS |
2074 | struct common_audit_data ad; |
2075 | int rc; | |
2076 | ||
2077 | ad.type = LSM_AUDIT_DATA_PATH; | |
2078 | ad.u.path = file->f_path; | |
2079 | ||
2080 | if (sid != fsec->sid) { | |
6b6bc620 SS |
2081 | rc = avc_has_perm(&selinux_state, |
2082 | sid, fsec->sid, | |
79af7307 SS |
2083 | SECCLASS_FD, |
2084 | FD__USE, | |
2085 | &ad); | |
2086 | if (rc) | |
2087 | return rc; | |
2088 | } | |
2089 | ||
f66e448c CF |
2090 | #ifdef CONFIG_BPF_SYSCALL |
2091 | rc = bpf_fd_pass(file, sid); | |
2092 | if (rc) | |
2093 | return rc; | |
2094 | #endif | |
2095 | ||
83da53c5 | 2096 | if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) |
79af7307 SS |
2097 | return 0; |
2098 | ||
20cdef8d | 2099 | isec = backing_inode_security(dentry); |
6b6bc620 SS |
2100 | return avc_has_perm(&selinux_state, |
2101 | sid, isec->sid, isec->sclass, file_to_av(file), | |
79af7307 SS |
2102 | &ad); |
2103 | } | |
2104 | ||
9e48858f | 2105 | static int selinux_ptrace_access_check(struct task_struct *child, |
5cd9c58f | 2106 | unsigned int mode) |
1da177e4 | 2107 | { |
be0554c9 SS |
2108 | u32 sid = current_sid(); |
2109 | u32 csid = task_sid(child); | |
2110 | ||
2111 | if (mode & PTRACE_MODE_READ) | |
6b6bc620 SS |
2112 | return avc_has_perm(&selinux_state, |
2113 | sid, csid, SECCLASS_FILE, FILE__READ, NULL); | |
006ebb40 | 2114 | |
6b6bc620 SS |
2115 | return avc_has_perm(&selinux_state, |
2116 | sid, csid, SECCLASS_PROCESS, PROCESS__PTRACE, NULL); | |
5cd9c58f DH |
2117 | } |
2118 | ||
2119 | static int selinux_ptrace_traceme(struct task_struct *parent) | |
2120 | { | |
6b6bc620 SS |
2121 | return avc_has_perm(&selinux_state, |
2122 | task_sid(parent), current_sid(), SECCLASS_PROCESS, | |
be0554c9 | 2123 | PROCESS__PTRACE, NULL); |
1da177e4 LT |
2124 | } |
2125 | ||
2126 | static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, | |
828dfe1d | 2127 | kernel_cap_t *inheritable, kernel_cap_t *permitted) |
1da177e4 | 2128 | { |
6b6bc620 SS |
2129 | return avc_has_perm(&selinux_state, |
2130 | current_sid(), task_sid(target), SECCLASS_PROCESS, | |
be0554c9 | 2131 | PROCESS__GETCAP, NULL); |
1da177e4 LT |
2132 | } |
2133 | ||
d84f4f99 DH |
2134 | static int selinux_capset(struct cred *new, const struct cred *old, |
2135 | const kernel_cap_t *effective, | |
2136 | const kernel_cap_t *inheritable, | |
2137 | const kernel_cap_t *permitted) | |
1da177e4 | 2138 | { |
6b6bc620 SS |
2139 | return avc_has_perm(&selinux_state, |
2140 | cred_sid(old), cred_sid(new), SECCLASS_PROCESS, | |
be0554c9 | 2141 | PROCESS__SETCAP, NULL); |
1da177e4 LT |
2142 | } |
2143 | ||
5626d3e8 JM |
2144 | /* |
2145 | * (This comment used to live with the selinux_task_setuid hook, | |
2146 | * which was removed). | |
2147 | * | |
2148 | * Since setuid only affects the current process, and since the SELinux | |
2149 | * controls are not based on the Linux identity attributes, SELinux does not | |
2150 | * need to control this operation. However, SELinux does control the use of | |
2151 | * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. | |
2152 | */ | |
2153 | ||
6a9de491 | 2154 | static int selinux_capable(const struct cred *cred, struct user_namespace *ns, |
c1a85a00 | 2155 | int cap, unsigned int opts) |
1da177e4 | 2156 | { |
c1a85a00 | 2157 | return cred_has_capability(cred, cap, opts, ns == &init_user_ns); |
1da177e4 LT |
2158 | } |
2159 | ||
1da177e4 LT |
2160 | static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) |
2161 | { | |
88e67f3b | 2162 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2163 | int rc = 0; |
2164 | ||
2165 | if (!sb) | |
2166 | return 0; | |
2167 | ||
2168 | switch (cmds) { | |
828dfe1d EP |
2169 | case Q_SYNC: |
2170 | case Q_QUOTAON: | |
2171 | case Q_QUOTAOFF: | |
2172 | case Q_SETINFO: | |
2173 | case Q_SETQUOTA: | |
88e67f3b | 2174 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); |
828dfe1d EP |
2175 | break; |
2176 | case Q_GETFMT: | |
2177 | case Q_GETINFO: | |
2178 | case Q_GETQUOTA: | |
88e67f3b | 2179 | rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); |
828dfe1d EP |
2180 | break; |
2181 | default: | |
2182 | rc = 0; /* let the kernel handle invalid cmds */ | |
2183 | break; | |
1da177e4 LT |
2184 | } |
2185 | return rc; | |
2186 | } | |
2187 | ||
2188 | static int selinux_quota_on(struct dentry *dentry) | |
2189 | { | |
88e67f3b DH |
2190 | const struct cred *cred = current_cred(); |
2191 | ||
2875fa00 | 2192 | return dentry_has_perm(cred, dentry, FILE__QUOTAON); |
1da177e4 LT |
2193 | } |
2194 | ||
12b3052c | 2195 | static int selinux_syslog(int type) |
1da177e4 | 2196 | { |
1da177e4 | 2197 | switch (type) { |
d78ca3cd KC |
2198 | case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ |
2199 | case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ | |
6b6bc620 SS |
2200 | return avc_has_perm(&selinux_state, |
2201 | current_sid(), SECINITSID_KERNEL, | |
be0554c9 | 2202 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_READ, NULL); |
d78ca3cd KC |
2203 | case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ |
2204 | case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ | |
2205 | /* Set level of messages printed to console */ | |
2206 | case SYSLOG_ACTION_CONSOLE_LEVEL: | |
6b6bc620 SS |
2207 | return avc_has_perm(&selinux_state, |
2208 | current_sid(), SECINITSID_KERNEL, | |
be0554c9 SS |
2209 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_CONSOLE, |
2210 | NULL); | |
1da177e4 | 2211 | } |
be0554c9 | 2212 | /* All other syslog types */ |
6b6bc620 SS |
2213 | return avc_has_perm(&selinux_state, |
2214 | current_sid(), SECINITSID_KERNEL, | |
be0554c9 | 2215 | SECCLASS_SYSTEM, SYSTEM__SYSLOG_MOD, NULL); |
1da177e4 LT |
2216 | } |
2217 | ||
2218 | /* | |
2219 | * Check that a process has enough memory to allocate a new virtual | |
2220 | * mapping. 0 means there is enough memory for the allocation to | |
2221 | * succeed and -ENOMEM implies there is not. | |
2222 | * | |
1da177e4 LT |
2223 | * Do not audit the selinux permission check, as this is applied to all |
2224 | * processes that allocate mappings. | |
2225 | */ | |
34b4e4aa | 2226 | static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
2227 | { |
2228 | int rc, cap_sys_admin = 0; | |
1da177e4 | 2229 | |
b1d9e6b0 | 2230 | rc = cred_has_capability(current_cred(), CAP_SYS_ADMIN, |
c1a85a00 | 2231 | CAP_OPT_NOAUDIT, true); |
1da177e4 LT |
2232 | if (rc == 0) |
2233 | cap_sys_admin = 1; | |
2234 | ||
b1d9e6b0 | 2235 | return cap_sys_admin; |
1da177e4 LT |
2236 | } |
2237 | ||
2238 | /* binprm security operations */ | |
2239 | ||
be0554c9 | 2240 | static u32 ptrace_parent_sid(void) |
0c6181cb PM |
2241 | { |
2242 | u32 sid = 0; | |
2243 | struct task_struct *tracer; | |
2244 | ||
2245 | rcu_read_lock(); | |
be0554c9 | 2246 | tracer = ptrace_parent(current); |
0c6181cb PM |
2247 | if (tracer) |
2248 | sid = task_sid(tracer); | |
2249 | rcu_read_unlock(); | |
2250 | ||
2251 | return sid; | |
2252 | } | |
2253 | ||
7b0d0b40 SS |
2254 | static int check_nnp_nosuid(const struct linux_binprm *bprm, |
2255 | const struct task_security_struct *old_tsec, | |
2256 | const struct task_security_struct *new_tsec) | |
2257 | { | |
2258 | int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); | |
380cf5ba | 2259 | int nosuid = !mnt_may_suid(bprm->file->f_path.mnt); |
7b0d0b40 | 2260 | int rc; |
af63f419 | 2261 | u32 av; |
7b0d0b40 SS |
2262 | |
2263 | if (!nnp && !nosuid) | |
2264 | return 0; /* neither NNP nor nosuid */ | |
2265 | ||
2266 | if (new_tsec->sid == old_tsec->sid) | |
2267 | return 0; /* No change in credentials */ | |
2268 | ||
2269 | /* | |
af63f419 SS |
2270 | * If the policy enables the nnp_nosuid_transition policy capability, |
2271 | * then we permit transitions under NNP or nosuid if the | |
2272 | * policy allows the corresponding permission between | |
2273 | * the old and new contexts. | |
7b0d0b40 | 2274 | */ |
aa8e712c | 2275 | if (selinux_policycap_nnp_nosuid_transition()) { |
af63f419 | 2276 | av = 0; |
7b0d0b40 | 2277 | if (nnp) |
af63f419 SS |
2278 | av |= PROCESS2__NNP_TRANSITION; |
2279 | if (nosuid) | |
2280 | av |= PROCESS2__NOSUID_TRANSITION; | |
6b6bc620 SS |
2281 | rc = avc_has_perm(&selinux_state, |
2282 | old_tsec->sid, new_tsec->sid, | |
af63f419 SS |
2283 | SECCLASS_PROCESS2, av, NULL); |
2284 | if (!rc) | |
2285 | return 0; | |
7b0d0b40 | 2286 | } |
af63f419 SS |
2287 | |
2288 | /* | |
2289 | * We also permit NNP or nosuid transitions to bounded SIDs, | |
2290 | * i.e. SIDs that are guaranteed to only be allowed a subset | |
2291 | * of the permissions of the current SID. | |
2292 | */ | |
aa8e712c SS |
2293 | rc = security_bounded_transition(&selinux_state, old_tsec->sid, |
2294 | new_tsec->sid); | |
af63f419 SS |
2295 | if (!rc) |
2296 | return 0; | |
2297 | ||
2298 | /* | |
2299 | * On failure, preserve the errno values for NNP vs nosuid. | |
2300 | * NNP: Operation not permitted for caller. | |
2301 | * nosuid: Permission denied to file. | |
2302 | */ | |
2303 | if (nnp) | |
2304 | return -EPERM; | |
2305 | return -EACCES; | |
7b0d0b40 SS |
2306 | } |
2307 | ||
a6f76f23 | 2308 | static int selinux_bprm_set_creds(struct linux_binprm *bprm) |
1da177e4 | 2309 | { |
a6f76f23 DH |
2310 | const struct task_security_struct *old_tsec; |
2311 | struct task_security_struct *new_tsec; | |
1da177e4 | 2312 | struct inode_security_struct *isec; |
2bf49690 | 2313 | struct common_audit_data ad; |
496ad9aa | 2314 | struct inode *inode = file_inode(bprm->file); |
1da177e4 LT |
2315 | int rc; |
2316 | ||
a6f76f23 DH |
2317 | /* SELinux context only depends on initial program or script and not |
2318 | * the script interpreter */ | |
ddb4a144 | 2319 | if (bprm->called_set_creds) |
1da177e4 LT |
2320 | return 0; |
2321 | ||
0c6cfa62 CS |
2322 | old_tsec = selinux_cred(current_cred()); |
2323 | new_tsec = selinux_cred(bprm->cred); | |
83da53c5 | 2324 | isec = inode_security(inode); |
1da177e4 LT |
2325 | |
2326 | /* Default to the current task SID. */ | |
a6f76f23 DH |
2327 | new_tsec->sid = old_tsec->sid; |
2328 | new_tsec->osid = old_tsec->sid; | |
1da177e4 | 2329 | |
28eba5bf | 2330 | /* Reset fs, key, and sock SIDs on execve. */ |
a6f76f23 DH |
2331 | new_tsec->create_sid = 0; |
2332 | new_tsec->keycreate_sid = 0; | |
2333 | new_tsec->sockcreate_sid = 0; | |
1da177e4 | 2334 | |
a6f76f23 DH |
2335 | if (old_tsec->exec_sid) { |
2336 | new_tsec->sid = old_tsec->exec_sid; | |
1da177e4 | 2337 | /* Reset exec SID on execve. */ |
a6f76f23 | 2338 | new_tsec->exec_sid = 0; |
259e5e6c | 2339 | |
7b0d0b40 SS |
2340 | /* Fail on NNP or nosuid if not an allowed transition. */ |
2341 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2342 | if (rc) | |
2343 | return rc; | |
1da177e4 LT |
2344 | } else { |
2345 | /* Check for a default transition on this program. */ | |
aa8e712c SS |
2346 | rc = security_transition_sid(&selinux_state, old_tsec->sid, |
2347 | isec->sid, SECCLASS_PROCESS, NULL, | |
652bb9b0 | 2348 | &new_tsec->sid); |
1da177e4 LT |
2349 | if (rc) |
2350 | return rc; | |
7b0d0b40 SS |
2351 | |
2352 | /* | |
2353 | * Fallback to old SID on NNP or nosuid if not an allowed | |
2354 | * transition. | |
2355 | */ | |
2356 | rc = check_nnp_nosuid(bprm, old_tsec, new_tsec); | |
2357 | if (rc) | |
2358 | new_tsec->sid = old_tsec->sid; | |
1da177e4 LT |
2359 | } |
2360 | ||
43af5de7 VG |
2361 | ad.type = LSM_AUDIT_DATA_FILE; |
2362 | ad.u.file = bprm->file; | |
1da177e4 | 2363 | |
a6f76f23 | 2364 | if (new_tsec->sid == old_tsec->sid) { |
6b6bc620 SS |
2365 | rc = avc_has_perm(&selinux_state, |
2366 | old_tsec->sid, isec->sid, | |
1da177e4 LT |
2367 | SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); |
2368 | if (rc) | |
2369 | return rc; | |
2370 | } else { | |
2371 | /* Check permissions for the transition. */ | |
6b6bc620 SS |
2372 | rc = avc_has_perm(&selinux_state, |
2373 | old_tsec->sid, new_tsec->sid, | |
1da177e4 LT |
2374 | SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); |
2375 | if (rc) | |
2376 | return rc; | |
2377 | ||
6b6bc620 SS |
2378 | rc = avc_has_perm(&selinux_state, |
2379 | new_tsec->sid, isec->sid, | |
1da177e4 LT |
2380 | SECCLASS_FILE, FILE__ENTRYPOINT, &ad); |
2381 | if (rc) | |
2382 | return rc; | |
2383 | ||
a6f76f23 DH |
2384 | /* Check for shared state */ |
2385 | if (bprm->unsafe & LSM_UNSAFE_SHARE) { | |
6b6bc620 SS |
2386 | rc = avc_has_perm(&selinux_state, |
2387 | old_tsec->sid, new_tsec->sid, | |
a6f76f23 DH |
2388 | SECCLASS_PROCESS, PROCESS__SHARE, |
2389 | NULL); | |
2390 | if (rc) | |
2391 | return -EPERM; | |
2392 | } | |
2393 | ||
2394 | /* Make sure that anyone attempting to ptrace over a task that | |
2395 | * changes its SID has the appropriate permit */ | |
9227dd2a | 2396 | if (bprm->unsafe & LSM_UNSAFE_PTRACE) { |
be0554c9 | 2397 | u32 ptsid = ptrace_parent_sid(); |
a6f76f23 | 2398 | if (ptsid != 0) { |
6b6bc620 SS |
2399 | rc = avc_has_perm(&selinux_state, |
2400 | ptsid, new_tsec->sid, | |
a6f76f23 DH |
2401 | SECCLASS_PROCESS, |
2402 | PROCESS__PTRACE, NULL); | |
2403 | if (rc) | |
2404 | return -EPERM; | |
2405 | } | |
2406 | } | |
1da177e4 | 2407 | |
a6f76f23 DH |
2408 | /* Clear any possibly unsafe personality bits on exec: */ |
2409 | bprm->per_clear |= PER_CLEAR_ON_SETID; | |
275bb41e | 2410 | |
1da177e4 LT |
2411 | /* Enable secure mode for SIDs transitions unless |
2412 | the noatsecure permission is granted between | |
2413 | the two SIDs, i.e. ahp returns 0. */ | |
6b6bc620 SS |
2414 | rc = avc_has_perm(&selinux_state, |
2415 | old_tsec->sid, new_tsec->sid, | |
62874c3a KC |
2416 | SECCLASS_PROCESS, PROCESS__NOATSECURE, |
2417 | NULL); | |
2418 | bprm->secureexec |= !!rc; | |
1da177e4 LT |
2419 | } |
2420 | ||
62874c3a | 2421 | return 0; |
1da177e4 LT |
2422 | } |
2423 | ||
c3c073f8 AV |
2424 | static int match_file(const void *p, struct file *file, unsigned fd) |
2425 | { | |
2426 | return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; | |
2427 | } | |
2428 | ||
1da177e4 | 2429 | /* Derived from fs/exec.c:flush_old_files. */ |
745ca247 DH |
2430 | static inline void flush_unauthorized_files(const struct cred *cred, |
2431 | struct files_struct *files) | |
1da177e4 | 2432 | { |
1da177e4 | 2433 | struct file *file, *devnull = NULL; |
b20c8122 | 2434 | struct tty_struct *tty; |
24ec839c | 2435 | int drop_tty = 0; |
c3c073f8 | 2436 | unsigned n; |
1da177e4 | 2437 | |
24ec839c | 2438 | tty = get_current_tty(); |
1da177e4 | 2439 | if (tty) { |
4a510969 | 2440 | spin_lock(&tty->files_lock); |
37dd0bd0 | 2441 | if (!list_empty(&tty->tty_files)) { |
d996b62a | 2442 | struct tty_file_private *file_priv; |
37dd0bd0 | 2443 | |
1da177e4 | 2444 | /* Revalidate access to controlling tty. |
13f8e981 DH |
2445 | Use file_path_has_perm on the tty path directly |
2446 | rather than using file_has_perm, as this particular | |
2447 | open file may belong to another process and we are | |
2448 | only interested in the inode-based check here. */ | |
d996b62a NP |
2449 | file_priv = list_first_entry(&tty->tty_files, |
2450 | struct tty_file_private, list); | |
2451 | file = file_priv->file; | |
13f8e981 | 2452 | if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE)) |
24ec839c | 2453 | drop_tty = 1; |
1da177e4 | 2454 | } |
4a510969 | 2455 | spin_unlock(&tty->files_lock); |
452a00d2 | 2456 | tty_kref_put(tty); |
1da177e4 | 2457 | } |
98a27ba4 EB |
2458 | /* Reset controlling tty. */ |
2459 | if (drop_tty) | |
2460 | no_tty(); | |
1da177e4 LT |
2461 | |
2462 | /* Revalidate access to inherited open files. */ | |
c3c073f8 AV |
2463 | n = iterate_fd(files, 0, match_file, cred); |
2464 | if (!n) /* none found? */ | |
2465 | return; | |
1da177e4 | 2466 | |
c3c073f8 | 2467 | devnull = dentry_open(&selinux_null, O_RDWR, cred); |
45525b26 AV |
2468 | if (IS_ERR(devnull)) |
2469 | devnull = NULL; | |
2470 | /* replace all the matching ones with this */ | |
2471 | do { | |
2472 | replace_fd(n - 1, devnull, 0); | |
2473 | } while ((n = iterate_fd(files, n, match_file, cred)) != 0); | |
2474 | if (devnull) | |
c3c073f8 | 2475 | fput(devnull); |
1da177e4 LT |
2476 | } |
2477 | ||
a6f76f23 DH |
2478 | /* |
2479 | * Prepare a process for imminent new credential changes due to exec | |
2480 | */ | |
2481 | static void selinux_bprm_committing_creds(struct linux_binprm *bprm) | |
1da177e4 | 2482 | { |
a6f76f23 DH |
2483 | struct task_security_struct *new_tsec; |
2484 | struct rlimit *rlim, *initrlim; | |
2485 | int rc, i; | |
d84f4f99 | 2486 | |
0c6cfa62 | 2487 | new_tsec = selinux_cred(bprm->cred); |
a6f76f23 DH |
2488 | if (new_tsec->sid == new_tsec->osid) |
2489 | return; | |
1da177e4 | 2490 | |
a6f76f23 DH |
2491 | /* Close files for which the new task SID is not authorized. */ |
2492 | flush_unauthorized_files(bprm->cred, current->files); | |
0356357c | 2493 | |
a6f76f23 DH |
2494 | /* Always clear parent death signal on SID transitions. */ |
2495 | current->pdeath_signal = 0; | |
0356357c | 2496 | |
a6f76f23 DH |
2497 | /* Check whether the new SID can inherit resource limits from the old |
2498 | * SID. If not, reset all soft limits to the lower of the current | |
2499 | * task's hard limit and the init task's soft limit. | |
2500 | * | |
2501 | * Note that the setting of hard limits (even to lower them) can be | |
2502 | * controlled by the setrlimit check. The inclusion of the init task's | |
2503 | * soft limit into the computation is to avoid resetting soft limits | |
2504 | * higher than the default soft limit for cases where the default is | |
2505 | * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. | |
2506 | */ | |
6b6bc620 SS |
2507 | rc = avc_has_perm(&selinux_state, |
2508 | new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, | |
a6f76f23 DH |
2509 | PROCESS__RLIMITINH, NULL); |
2510 | if (rc) { | |
eb2d55a3 ON |
2511 | /* protect against do_prlimit() */ |
2512 | task_lock(current); | |
a6f76f23 DH |
2513 | for (i = 0; i < RLIM_NLIMITS; i++) { |
2514 | rlim = current->signal->rlim + i; | |
2515 | initrlim = init_task.signal->rlim + i; | |
2516 | rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); | |
1da177e4 | 2517 | } |
eb2d55a3 | 2518 | task_unlock(current); |
baa73d9e NP |
2519 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) |
2520 | update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); | |
1da177e4 LT |
2521 | } |
2522 | } | |
2523 | ||
2524 | /* | |
a6f76f23 DH |
2525 | * Clean up the process immediately after the installation of new credentials |
2526 | * due to exec | |
1da177e4 | 2527 | */ |
a6f76f23 | 2528 | static void selinux_bprm_committed_creds(struct linux_binprm *bprm) |
1da177e4 | 2529 | { |
0c6cfa62 | 2530 | const struct task_security_struct *tsec = selinux_cred(current_cred()); |
1da177e4 | 2531 | struct itimerval itimer; |
a6f76f23 | 2532 | u32 osid, sid; |
1da177e4 LT |
2533 | int rc, i; |
2534 | ||
a6f76f23 DH |
2535 | osid = tsec->osid; |
2536 | sid = tsec->sid; | |
2537 | ||
2538 | if (sid == osid) | |
1da177e4 LT |
2539 | return; |
2540 | ||
a6f76f23 DH |
2541 | /* Check whether the new SID can inherit signal state from the old SID. |
2542 | * If not, clear itimers to avoid subsequent signal generation and | |
2543 | * flush and unblock signals. | |
2544 | * | |
2545 | * This must occur _after_ the task SID has been updated so that any | |
2546 | * kill done after the flush will be checked against the new SID. | |
2547 | */ | |
6b6bc620 SS |
2548 | rc = avc_has_perm(&selinux_state, |
2549 | osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); | |
1da177e4 | 2550 | if (rc) { |
baa73d9e NP |
2551 | if (IS_ENABLED(CONFIG_POSIX_TIMERS)) { |
2552 | memset(&itimer, 0, sizeof itimer); | |
2553 | for (i = 0; i < 3; i++) | |
2554 | do_setitimer(i, &itimer, NULL); | |
2555 | } | |
1da177e4 | 2556 | spin_lock_irq(¤t->sighand->siglock); |
9e7c8f8c ON |
2557 | if (!fatal_signal_pending(current)) { |
2558 | flush_sigqueue(¤t->pending); | |
2559 | flush_sigqueue(¤t->signal->shared_pending); | |
3bcac026 DH |
2560 | flush_signal_handlers(current, 1); |
2561 | sigemptyset(¤t->blocked); | |
9e7c8f8c | 2562 | recalc_sigpending(); |
3bcac026 | 2563 | } |
1da177e4 LT |
2564 | spin_unlock_irq(¤t->sighand->siglock); |
2565 | } | |
2566 | ||
a6f76f23 DH |
2567 | /* Wake up the parent if it is waiting so that it can recheck |
2568 | * wait permission to the new task SID. */ | |
ecd6de3c | 2569 | read_lock(&tasklist_lock); |
0b7570e7 | 2570 | __wake_up_parent(current, current->real_parent); |
ecd6de3c | 2571 | read_unlock(&tasklist_lock); |
1da177e4 LT |
2572 | } |
2573 | ||
2574 | /* superblock security operations */ | |
2575 | ||
2576 | static int selinux_sb_alloc_security(struct super_block *sb) | |
2577 | { | |
2578 | return superblock_alloc_security(sb); | |
2579 | } | |
2580 | ||
2581 | static void selinux_sb_free_security(struct super_block *sb) | |
2582 | { | |
2583 | superblock_free_security(sb); | |
2584 | } | |
2585 | ||
99dbbb59 | 2586 | static inline int opt_len(const char *s) |
1da177e4 | 2587 | { |
99dbbb59 AV |
2588 | bool open_quote = false; |
2589 | int len; | |
2590 | char c; | |
1da177e4 | 2591 | |
99dbbb59 AV |
2592 | for (len = 0; (c = s[len]) != '\0'; len++) { |
2593 | if (c == '"') | |
2594 | open_quote = !open_quote; | |
2595 | if (c == ',' && !open_quote) | |
2596 | break; | |
3528a953 | 2597 | } |
99dbbb59 | 2598 | return len; |
3528a953 CO |
2599 | } |
2600 | ||
99dbbb59 | 2601 | static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts) |
1da177e4 | 2602 | { |
99dbbb59 AV |
2603 | char *from = options; |
2604 | char *to = options; | |
2605 | bool first = true; | |
1da177e4 | 2606 | |
99dbbb59 AV |
2607 | while (1) { |
2608 | int len = opt_len(from); | |
2609 | int token, rc; | |
2610 | char *arg = NULL; | |
1da177e4 | 2611 | |
99dbbb59 | 2612 | token = match_opt_prefix(from, len, &arg); |
1da177e4 | 2613 | |
99dbbb59 AV |
2614 | if (token != Opt_error) { |
2615 | char *p, *q; | |
1da177e4 | 2616 | |
99dbbb59 AV |
2617 | /* strip quotes */ |
2618 | if (arg) { | |
2619 | for (p = q = arg; p < from + len; p++) { | |
2620 | char c = *p; | |
2621 | if (c != '"') | |
2622 | *q++ = c; | |
2623 | } | |
2624 | arg = kmemdup_nul(arg, q - arg, GFP_KERNEL); | |
2625 | } | |
2626 | rc = selinux_add_opt(token, arg, mnt_opts); | |
2627 | if (unlikely(rc)) { | |
2628 | kfree(arg); | |
2629 | if (*mnt_opts) { | |
2630 | selinux_free_mnt_opts(*mnt_opts); | |
2631 | *mnt_opts = NULL; | |
2632 | } | |
2633 | return rc; | |
2634 | } | |
2635 | } else { | |
2636 | if (!first) { // copy with preceding comma | |
2637 | from--; | |
2638 | len++; | |
2639 | } | |
2640 | if (to != from) | |
2641 | memmove(to, from, len); | |
2642 | to += len; | |
2643 | first = false; | |
1da177e4 | 2644 | } |
99dbbb59 AV |
2645 | if (!from[len]) |
2646 | break; | |
2647 | from += len + 1; | |
2648 | } | |
2649 | *to = '\0'; | |
2650 | return 0; | |
1da177e4 LT |
2651 | } |
2652 | ||
204cc0cc | 2653 | static int selinux_sb_remount(struct super_block *sb, void *mnt_opts) |
026eb167 | 2654 | { |
bd323655 | 2655 | struct selinux_mnt_opts *opts = mnt_opts; |
026eb167 | 2656 | struct superblock_security_struct *sbsec = sb->s_security; |
bd323655 AV |
2657 | u32 sid; |
2658 | int rc; | |
026eb167 EP |
2659 | |
2660 | if (!(sbsec->flags & SE_SBINITIALIZED)) | |
2661 | return 0; | |
2662 | ||
204cc0cc | 2663 | if (!opts) |
026eb167 EP |
2664 | return 0; |
2665 | ||
bd323655 AV |
2666 | if (opts->fscontext) { |
2667 | rc = parse_sid(sb, opts->fscontext, &sid); | |
2668 | if (rc) | |
c039bc3c | 2669 | return rc; |
bd323655 AV |
2670 | if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) |
2671 | goto out_bad_option; | |
026eb167 | 2672 | } |
bd323655 AV |
2673 | if (opts->context) { |
2674 | rc = parse_sid(sb, opts->context, &sid); | |
2675 | if (rc) | |
2676 | return rc; | |
2677 | if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) | |
2678 | goto out_bad_option; | |
2679 | } | |
2680 | if (opts->rootcontext) { | |
2681 | struct inode_security_struct *root_isec; | |
2682 | root_isec = backing_inode_security(sb->s_root); | |
2683 | rc = parse_sid(sb, opts->rootcontext, &sid); | |
2684 | if (rc) | |
2685 | return rc; | |
2686 | if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) | |
2687 | goto out_bad_option; | |
2688 | } | |
2689 | if (opts->defcontext) { | |
2690 | rc = parse_sid(sb, opts->defcontext, &sid); | |
2691 | if (rc) | |
2692 | return rc; | |
2693 | if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) | |
2694 | goto out_bad_option; | |
026eb167 | 2695 | } |
c039bc3c | 2696 | return 0; |
026eb167 | 2697 | |
026eb167 | 2698 | out_bad_option: |
c103a91e | 2699 | pr_warn("SELinux: unable to change security options " |
29b1deb2 LT |
2700 | "during remount (dev %s, type=%s)\n", sb->s_id, |
2701 | sb->s_type->name); | |
c039bc3c | 2702 | return -EINVAL; |
026eb167 EP |
2703 | } |
2704 | ||
a10d7c22 | 2705 | static int selinux_sb_kern_mount(struct super_block *sb) |
1da177e4 | 2706 | { |
88e67f3b | 2707 | const struct cred *cred = current_cred(); |
2bf49690 | 2708 | struct common_audit_data ad; |
74192246 | 2709 | |
50c205f5 | 2710 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2711 | ad.u.dentry = sb->s_root; |
88e67f3b | 2712 | return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); |
1da177e4 LT |
2713 | } |
2714 | ||
726c3342 | 2715 | static int selinux_sb_statfs(struct dentry *dentry) |
1da177e4 | 2716 | { |
88e67f3b | 2717 | const struct cred *cred = current_cred(); |
2bf49690 | 2718 | struct common_audit_data ad; |
1da177e4 | 2719 | |
50c205f5 | 2720 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 2721 | ad.u.dentry = dentry->d_sb->s_root; |
88e67f3b | 2722 | return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); |
1da177e4 LT |
2723 | } |
2724 | ||
808d4e3c | 2725 | static int selinux_mount(const char *dev_name, |
8a04c43b | 2726 | const struct path *path, |
808d4e3c | 2727 | const char *type, |
828dfe1d EP |
2728 | unsigned long flags, |
2729 | void *data) | |
1da177e4 | 2730 | { |
88e67f3b | 2731 | const struct cred *cred = current_cred(); |
1da177e4 LT |
2732 | |
2733 | if (flags & MS_REMOUNT) | |
d8c9584e | 2734 | return superblock_has_perm(cred, path->dentry->d_sb, |
828dfe1d | 2735 | FILESYSTEM__REMOUNT, NULL); |
1da177e4 | 2736 | else |
2875fa00 | 2737 | return path_has_perm(cred, path, FILE__MOUNTON); |
1da177e4 LT |
2738 | } |
2739 | ||
2740 | static int selinux_umount(struct vfsmount *mnt, int flags) | |
2741 | { | |
88e67f3b | 2742 | const struct cred *cred = current_cred(); |
1da177e4 | 2743 | |
88e67f3b | 2744 | return superblock_has_perm(cred, mnt->mnt_sb, |
828dfe1d | 2745 | FILESYSTEM__UNMOUNT, NULL); |
1da177e4 LT |
2746 | } |
2747 | ||
0b52075e AV |
2748 | static int selinux_fs_context_dup(struct fs_context *fc, |
2749 | struct fs_context *src_fc) | |
2750 | { | |
2751 | const struct selinux_mnt_opts *src = src_fc->security; | |
2752 | struct selinux_mnt_opts *opts; | |
2753 | ||
2754 | if (!src) | |
2755 | return 0; | |
2756 | ||
2757 | fc->security = kzalloc(sizeof(struct selinux_mnt_opts), GFP_KERNEL); | |
2758 | if (!fc->security) | |
2759 | return -ENOMEM; | |
2760 | ||
2761 | opts = fc->security; | |
2762 | ||
2763 | if (src->fscontext) { | |
2764 | opts->fscontext = kstrdup(src->fscontext, GFP_KERNEL); | |
2765 | if (!opts->fscontext) | |
2766 | return -ENOMEM; | |
2767 | } | |
2768 | if (src->context) { | |
2769 | opts->context = kstrdup(src->context, GFP_KERNEL); | |
2770 | if (!opts->context) | |
2771 | return -ENOMEM; | |
2772 | } | |
2773 | if (src->rootcontext) { | |
2774 | opts->rootcontext = kstrdup(src->rootcontext, GFP_KERNEL); | |
2775 | if (!opts->rootcontext) | |
2776 | return -ENOMEM; | |
2777 | } | |
2778 | if (src->defcontext) { | |
2779 | opts->defcontext = kstrdup(src->defcontext, GFP_KERNEL); | |
2780 | if (!opts->defcontext) | |
2781 | return -ENOMEM; | |
2782 | } | |
2783 | return 0; | |
2784 | } | |
2785 | ||
442155c1 DH |
2786 | static const struct fs_parameter_spec selinux_param_specs[] = { |
2787 | fsparam_string(CONTEXT_STR, Opt_context), | |
2788 | fsparam_string(DEFCONTEXT_STR, Opt_defcontext), | |
2789 | fsparam_string(FSCONTEXT_STR, Opt_fscontext), | |
2790 | fsparam_string(ROOTCONTEXT_STR, Opt_rootcontext), | |
2791 | fsparam_flag (SECLABEL_STR, Opt_seclabel), | |
2792 | {} | |
2793 | }; | |
2794 | ||
2795 | static const struct fs_parameter_description selinux_fs_parameters = { | |
2796 | .name = "SELinux", | |
2797 | .specs = selinux_param_specs, | |
2798 | }; | |
2799 | ||
2800 | static int selinux_fs_context_parse_param(struct fs_context *fc, | |
2801 | struct fs_parameter *param) | |
2802 | { | |
2803 | struct fs_parse_result result; | |
2804 | int opt, rc; | |
2805 | ||
2806 | opt = fs_parse(fc, &selinux_fs_parameters, param, &result); | |
2807 | if (opt < 0) | |
2808 | return opt; | |
2809 | ||
2810 | rc = selinux_add_opt(opt, param->string, &fc->security); | |
2811 | if (!rc) { | |
2812 | param->string = NULL; | |
2813 | rc = 1; | |
2814 | } | |
2815 | return rc; | |
2816 | } | |
2817 | ||
1da177e4 LT |
2818 | /* inode security operations */ |
2819 | ||
2820 | static int selinux_inode_alloc_security(struct inode *inode) | |
2821 | { | |
2822 | return inode_alloc_security(inode); | |
2823 | } | |
2824 | ||
2825 | static void selinux_inode_free_security(struct inode *inode) | |
2826 | { | |
2827 | inode_free_security(inode); | |
2828 | } | |
2829 | ||
d47be3df | 2830 | static int selinux_dentry_init_security(struct dentry *dentry, int mode, |
4f3ccd76 | 2831 | const struct qstr *name, void **ctx, |
d47be3df DQ |
2832 | u32 *ctxlen) |
2833 | { | |
d47be3df DQ |
2834 | u32 newsid; |
2835 | int rc; | |
2836 | ||
0c6cfa62 | 2837 | rc = selinux_determine_inode_label(selinux_cred(current_cred()), |
c957f6df | 2838 | d_inode(dentry->d_parent), name, |
c3c188b2 DH |
2839 | inode_mode_to_security_class(mode), |
2840 | &newsid); | |
2841 | if (rc) | |
2842 | return rc; | |
d47be3df | 2843 | |
aa8e712c SS |
2844 | return security_sid_to_context(&selinux_state, newsid, (char **)ctx, |
2845 | ctxlen); | |
d47be3df DQ |
2846 | } |
2847 | ||
a518b0a5 VG |
2848 | static int selinux_dentry_create_files_as(struct dentry *dentry, int mode, |
2849 | struct qstr *name, | |
2850 | const struct cred *old, | |
2851 | struct cred *new) | |
2852 | { | |
2853 | u32 newsid; | |
2854 | int rc; | |
2855 | struct task_security_struct *tsec; | |
2856 | ||
0c6cfa62 | 2857 | rc = selinux_determine_inode_label(selinux_cred(old), |
a518b0a5 VG |
2858 | d_inode(dentry->d_parent), name, |
2859 | inode_mode_to_security_class(mode), | |
2860 | &newsid); | |
2861 | if (rc) | |
2862 | return rc; | |
2863 | ||
0c6cfa62 | 2864 | tsec = selinux_cred(new); |
a518b0a5 VG |
2865 | tsec->create_sid = newsid; |
2866 | return 0; | |
2867 | } | |
2868 | ||
5e41ff9e | 2869 | static int selinux_inode_init_security(struct inode *inode, struct inode *dir, |
9548906b TH |
2870 | const struct qstr *qstr, |
2871 | const char **name, | |
2a7dba39 | 2872 | void **value, size_t *len) |
5e41ff9e | 2873 | { |
0c6cfa62 | 2874 | const struct task_security_struct *tsec = selinux_cred(current_cred()); |
5e41ff9e | 2875 | struct superblock_security_struct *sbsec; |
c0d4f464 | 2876 | u32 newsid, clen; |
5e41ff9e | 2877 | int rc; |
9548906b | 2878 | char *context; |
5e41ff9e | 2879 | |
5e41ff9e | 2880 | sbsec = dir->i_sb->s_security; |
5e41ff9e | 2881 | |
275bb41e DH |
2882 | newsid = tsec->create_sid; |
2883 | ||
0c6cfa62 | 2884 | rc = selinux_determine_inode_label(selinux_cred(current_cred()), |
c3c188b2 DH |
2885 | dir, qstr, |
2886 | inode_mode_to_security_class(inode->i_mode), | |
2887 | &newsid); | |
2888 | if (rc) | |
2889 | return rc; | |
5e41ff9e | 2890 | |
296fddf7 | 2891 | /* Possibly defer initialization to selinux_complete_init. */ |
0d90a7ec | 2892 | if (sbsec->flags & SE_SBINITIALIZED) { |
80788c22 | 2893 | struct inode_security_struct *isec = selinux_inode(inode); |
296fddf7 EP |
2894 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
2895 | isec->sid = newsid; | |
6f3be9f5 | 2896 | isec->initialized = LABEL_INITIALIZED; |
296fddf7 | 2897 | } |
5e41ff9e | 2898 | |
aa8e712c | 2899 | if (!selinux_state.initialized || !(sbsec->flags & SBLABEL_MNT)) |
25a74f3b SS |
2900 | return -EOPNOTSUPP; |
2901 | ||
9548906b TH |
2902 | if (name) |
2903 | *name = XATTR_SELINUX_SUFFIX; | |
5e41ff9e | 2904 | |
570bc1c2 | 2905 | if (value && len) { |
aa8e712c SS |
2906 | rc = security_sid_to_context_force(&selinux_state, newsid, |
2907 | &context, &clen); | |
9548906b | 2908 | if (rc) |
570bc1c2 | 2909 | return rc; |
570bc1c2 SS |
2910 | *value = context; |
2911 | *len = clen; | |
5e41ff9e | 2912 | } |
5e41ff9e | 2913 | |
5e41ff9e SS |
2914 | return 0; |
2915 | } | |
2916 | ||
4acdaf27 | 2917 | static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) |
1da177e4 LT |
2918 | { |
2919 | return may_create(dir, dentry, SECCLASS_FILE); | |
2920 | } | |
2921 | ||
1da177e4 LT |
2922 | static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) |
2923 | { | |
1da177e4 LT |
2924 | return may_link(dir, old_dentry, MAY_LINK); |
2925 | } | |
2926 | ||
1da177e4 LT |
2927 | static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) |
2928 | { | |
1da177e4 LT |
2929 | return may_link(dir, dentry, MAY_UNLINK); |
2930 | } | |
2931 | ||
2932 | static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) | |
2933 | { | |
2934 | return may_create(dir, dentry, SECCLASS_LNK_FILE); | |
2935 | } | |
2936 | ||
18bb1db3 | 2937 | static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) |
1da177e4 LT |
2938 | { |
2939 | return may_create(dir, dentry, SECCLASS_DIR); | |
2940 | } | |
2941 | ||
1da177e4 LT |
2942 | static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) |
2943 | { | |
2944 | return may_link(dir, dentry, MAY_RMDIR); | |
2945 | } | |
2946 | ||
1a67aafb | 2947 | static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) |
1da177e4 | 2948 | { |
1da177e4 LT |
2949 | return may_create(dir, dentry, inode_mode_to_security_class(mode)); |
2950 | } | |
2951 | ||
1da177e4 | 2952 | static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, |
828dfe1d | 2953 | struct inode *new_inode, struct dentry *new_dentry) |
1da177e4 LT |
2954 | { |
2955 | return may_rename(old_inode, old_dentry, new_inode, new_dentry); | |
2956 | } | |
2957 | ||
1da177e4 LT |
2958 | static int selinux_inode_readlink(struct dentry *dentry) |
2959 | { | |
88e67f3b DH |
2960 | const struct cred *cred = current_cred(); |
2961 | ||
2875fa00 | 2962 | return dentry_has_perm(cred, dentry, FILE__READ); |
1da177e4 LT |
2963 | } |
2964 | ||
bda0be7a N |
2965 | static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode, |
2966 | bool rcu) | |
1da177e4 | 2967 | { |
88e67f3b | 2968 | const struct cred *cred = current_cred(); |
bda0be7a N |
2969 | struct common_audit_data ad; |
2970 | struct inode_security_struct *isec; | |
2971 | u32 sid; | |
1da177e4 | 2972 | |
bda0be7a N |
2973 | validate_creds(cred); |
2974 | ||
2975 | ad.type = LSM_AUDIT_DATA_DENTRY; | |
2976 | ad.u.dentry = dentry; | |
2977 | sid = cred_sid(cred); | |
5d226df4 AG |
2978 | isec = inode_security_rcu(inode, rcu); |
2979 | if (IS_ERR(isec)) | |
2980 | return PTR_ERR(isec); | |
bda0be7a | 2981 | |
e46e01ee SS |
2982 | return avc_has_perm(&selinux_state, |
2983 | sid, isec->sid, isec->sclass, FILE__READ, &ad); | |
1da177e4 LT |
2984 | } |
2985 | ||
d4cf970d EP |
2986 | static noinline int audit_inode_permission(struct inode *inode, |
2987 | u32 perms, u32 audited, u32 denied, | |
626b9740 | 2988 | int result, |
d4cf970d | 2989 | unsigned flags) |
1da177e4 | 2990 | { |
b782e0a6 | 2991 | struct common_audit_data ad; |
80788c22 | 2992 | struct inode_security_struct *isec = selinux_inode(inode); |
d4cf970d EP |
2993 | int rc; |
2994 | ||
50c205f5 | 2995 | ad.type = LSM_AUDIT_DATA_INODE; |
d4cf970d EP |
2996 | ad.u.inode = inode; |
2997 | ||
6b6bc620 SS |
2998 | rc = slow_avc_audit(&selinux_state, |
2999 | current_sid(), isec->sid, isec->sclass, perms, | |
626b9740 | 3000 | audited, denied, result, &ad, flags); |
d4cf970d EP |
3001 | if (rc) |
3002 | return rc; | |
3003 | return 0; | |
3004 | } | |
3005 | ||
e74f71eb | 3006 | static int selinux_inode_permission(struct inode *inode, int mask) |
1da177e4 | 3007 | { |
88e67f3b | 3008 | const struct cred *cred = current_cred(); |
b782e0a6 EP |
3009 | u32 perms; |
3010 | bool from_access; | |
cf1dd1da | 3011 | unsigned flags = mask & MAY_NOT_BLOCK; |
2e334057 EP |
3012 | struct inode_security_struct *isec; |
3013 | u32 sid; | |
3014 | struct av_decision avd; | |
3015 | int rc, rc2; | |
3016 | u32 audited, denied; | |
1da177e4 | 3017 | |
b782e0a6 | 3018 | from_access = mask & MAY_ACCESS; |
d09ca739 EP |
3019 | mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); |
3020 | ||
b782e0a6 EP |
3021 | /* No permission to check. Existence test. */ |
3022 | if (!mask) | |
1da177e4 | 3023 | return 0; |
1da177e4 | 3024 | |
2e334057 | 3025 | validate_creds(cred); |
b782e0a6 | 3026 | |
2e334057 EP |
3027 | if (unlikely(IS_PRIVATE(inode))) |
3028 | return 0; | |
b782e0a6 EP |
3029 | |
3030 | perms = file_mask_to_av(inode->i_mode, mask); | |
3031 | ||
2e334057 | 3032 | sid = cred_sid(cred); |
5d226df4 AG |
3033 | isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK); |
3034 | if (IS_ERR(isec)) | |
3035 | return PTR_ERR(isec); | |
2e334057 | 3036 | |
6b6bc620 | 3037 | rc = avc_has_perm_noaudit(&selinux_state, |
3a28cff3 SS |
3038 | sid, isec->sid, isec->sclass, perms, |
3039 | (flags & MAY_NOT_BLOCK) ? AVC_NONBLOCKING : 0, | |
3040 | &avd); | |
2e334057 EP |
3041 | audited = avc_audit_required(perms, &avd, rc, |
3042 | from_access ? FILE__AUDIT_ACCESS : 0, | |
3043 | &denied); | |
3044 | if (likely(!audited)) | |
3045 | return rc; | |
3046 | ||
626b9740 | 3047 | rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags); |
2e334057 EP |
3048 | if (rc2) |
3049 | return rc2; | |
3050 | return rc; | |
1da177e4 LT |
3051 | } |
3052 | ||
3053 | static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) | |
3054 | { | |
88e67f3b | 3055 | const struct cred *cred = current_cred(); |
ccb54478 | 3056 | struct inode *inode = d_backing_inode(dentry); |
bc6a6008 | 3057 | unsigned int ia_valid = iattr->ia_valid; |
95dbf739 | 3058 | __u32 av = FILE__WRITE; |
1da177e4 | 3059 | |
bc6a6008 AW |
3060 | /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ |
3061 | if (ia_valid & ATTR_FORCE) { | |
3062 | ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | | |
3063 | ATTR_FORCE); | |
3064 | if (!ia_valid) | |
3065 | return 0; | |
3066 | } | |
1da177e4 | 3067 | |
bc6a6008 AW |
3068 | if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | |
3069 | ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) | |
2875fa00 | 3070 | return dentry_has_perm(cred, dentry, FILE__SETATTR); |
1da177e4 | 3071 | |
aa8e712c | 3072 | if (selinux_policycap_openperm() && |
ccb54478 SS |
3073 | inode->i_sb->s_magic != SOCKFS_MAGIC && |
3074 | (ia_valid & ATTR_SIZE) && | |
3075 | !(ia_valid & ATTR_FILE)) | |
95dbf739 EP |
3076 | av |= FILE__OPEN; |
3077 | ||
3078 | return dentry_has_perm(cred, dentry, av); | |
1da177e4 LT |
3079 | } |
3080 | ||
3f7036a0 | 3081 | static int selinux_inode_getattr(const struct path *path) |
1da177e4 | 3082 | { |
3f7036a0 | 3083 | return path_has_perm(current_cred(), path, FILE__GETATTR); |
1da177e4 LT |
3084 | } |
3085 | ||
db59000a SS |
3086 | static bool has_cap_mac_admin(bool audit) |
3087 | { | |
3088 | const struct cred *cred = current_cred(); | |
c1a85a00 | 3089 | unsigned int opts = audit ? CAP_OPT_NONE : CAP_OPT_NOAUDIT; |
db59000a | 3090 | |
c1a85a00 | 3091 | if (cap_capable(cred, &init_user_ns, CAP_MAC_ADMIN, opts)) |
db59000a | 3092 | return false; |
c1a85a00 | 3093 | if (cred_has_capability(cred, CAP_MAC_ADMIN, opts, true)) |
db59000a SS |
3094 | return false; |
3095 | return true; | |
3096 | } | |
3097 | ||
8f0cfa52 DH |
3098 | static int selinux_inode_setxattr(struct dentry *dentry, const char *name, |
3099 | const void *value, size_t size, int flags) | |
1da177e4 | 3100 | { |
c6f493d6 | 3101 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3102 | struct inode_security_struct *isec; |
1da177e4 | 3103 | struct superblock_security_struct *sbsec; |
2bf49690 | 3104 | struct common_audit_data ad; |
275bb41e | 3105 | u32 newsid, sid = current_sid(); |
1da177e4 LT |
3106 | int rc = 0; |
3107 | ||
6b240306 EB |
3108 | if (strcmp(name, XATTR_NAME_SELINUX)) { |
3109 | rc = cap_inode_setxattr(dentry, name, value, size, flags); | |
3110 | if (rc) | |
3111 | return rc; | |
3112 | ||
3113 | /* Not an attribute we recognize, so just check the | |
3114 | ordinary setattr permission. */ | |
3115 | return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); | |
3116 | } | |
1da177e4 LT |
3117 | |
3118 | sbsec = inode->i_sb->s_security; | |
12f348b9 | 3119 | if (!(sbsec->flags & SBLABEL_MNT)) |
1da177e4 LT |
3120 | return -EOPNOTSUPP; |
3121 | ||
2e149670 | 3122 | if (!inode_owner_or_capable(inode)) |
1da177e4 LT |
3123 | return -EPERM; |
3124 | ||
50c205f5 | 3125 | ad.type = LSM_AUDIT_DATA_DENTRY; |
a269434d | 3126 | ad.u.dentry = dentry; |
1da177e4 | 3127 | |
20cdef8d | 3128 | isec = backing_inode_security(dentry); |
6b6bc620 SS |
3129 | rc = avc_has_perm(&selinux_state, |
3130 | sid, isec->sid, isec->sclass, | |
1da177e4 LT |
3131 | FILE__RELABELFROM, &ad); |
3132 | if (rc) | |
3133 | return rc; | |
3134 | ||
aa8e712c SS |
3135 | rc = security_context_to_sid(&selinux_state, value, size, &newsid, |
3136 | GFP_KERNEL); | |
12b29f34 | 3137 | if (rc == -EINVAL) { |
db59000a | 3138 | if (!has_cap_mac_admin(true)) { |
d6ea83ec EP |
3139 | struct audit_buffer *ab; |
3140 | size_t audit_size; | |
d6ea83ec EP |
3141 | |
3142 | /* We strip a nul only if it is at the end, otherwise the | |
3143 | * context contains a nul and we should audit that */ | |
e3fea3f7 | 3144 | if (value) { |
add24372 CIK |
3145 | const char *str = value; |
3146 | ||
e3fea3f7 AV |
3147 | if (str[size - 1] == '\0') |
3148 | audit_size = size - 1; | |
3149 | else | |
3150 | audit_size = size; | |
3151 | } else { | |
e3fea3f7 AV |
3152 | audit_size = 0; |
3153 | } | |
cdfb6b34 RGB |
3154 | ab = audit_log_start(audit_context(), |
3155 | GFP_ATOMIC, AUDIT_SELINUX_ERR); | |
d6ea83ec EP |
3156 | audit_log_format(ab, "op=setxattr invalid_context="); |
3157 | audit_log_n_untrustedstring(ab, value, audit_size); | |
3158 | audit_log_end(ab); | |
3159 | ||
12b29f34 | 3160 | return rc; |
d6ea83ec | 3161 | } |
aa8e712c SS |
3162 | rc = security_context_to_sid_force(&selinux_state, value, |
3163 | size, &newsid); | |
12b29f34 | 3164 | } |
1da177e4 LT |
3165 | if (rc) |
3166 | return rc; | |
3167 | ||
6b6bc620 SS |
3168 | rc = avc_has_perm(&selinux_state, |
3169 | sid, newsid, isec->sclass, | |
1da177e4 LT |
3170 | FILE__RELABELTO, &ad); |
3171 | if (rc) | |
3172 | return rc; | |
3173 | ||
aa8e712c SS |
3174 | rc = security_validate_transition(&selinux_state, isec->sid, newsid, |
3175 | sid, isec->sclass); | |
1da177e4 LT |
3176 | if (rc) |
3177 | return rc; | |
3178 | ||
6b6bc620 SS |
3179 | return avc_has_perm(&selinux_state, |
3180 | newsid, | |
1da177e4 LT |
3181 | sbsec->sid, |
3182 | SECCLASS_FILESYSTEM, | |
3183 | FILESYSTEM__ASSOCIATE, | |
3184 | &ad); | |
3185 | } | |
3186 | ||
8f0cfa52 | 3187 | static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, |
f5269710 | 3188 | const void *value, size_t size, |
8f0cfa52 | 3189 | int flags) |
1da177e4 | 3190 | { |
c6f493d6 | 3191 | struct inode *inode = d_backing_inode(dentry); |
20cdef8d | 3192 | struct inode_security_struct *isec; |
1da177e4 LT |
3193 | u32 newsid; |
3194 | int rc; | |
3195 | ||
3196 | if (strcmp(name, XATTR_NAME_SELINUX)) { | |
3197 | /* Not an attribute we recognize, so nothing to do. */ | |
3198 | return; | |
3199 | } | |
3200 | ||
aa8e712c SS |
3201 | rc = security_context_to_sid_force(&selinux_state, value, size, |
3202 | &newsid); | |
1da177e4 | 3203 | if (rc) { |
c103a91e | 3204 | pr_err("SELinux: unable to map context to SID" |
12b29f34 SS |
3205 | "for (%s, %lu), rc=%d\n", |
3206 | inode->i_sb->s_id, inode->i_ino, -rc); | |
1da177e4 LT |
3207 | return; |
3208 | } | |
3209 | ||
20cdef8d | 3210 | isec = backing_inode_security(dentry); |
9287aed2 | 3211 | spin_lock(&isec->lock); |
aa9c2669 | 3212 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3213 | isec->sid = newsid; |
6f3be9f5 | 3214 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3215 | spin_unlock(&isec->lock); |
aa9c2669 | 3216 | |
1da177e4 LT |
3217 | return; |
3218 | } | |
3219 | ||
8f0cfa52 | 3220 | static int selinux_inode_getxattr(struct dentry *dentry, const char *name) |
1da177e4 | 3221 | { |
88e67f3b DH |
3222 | const struct cred *cred = current_cred(); |
3223 | ||
2875fa00 | 3224 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3225 | } |
3226 | ||
828dfe1d | 3227 | static int selinux_inode_listxattr(struct dentry *dentry) |
1da177e4 | 3228 | { |
88e67f3b DH |
3229 | const struct cred *cred = current_cred(); |
3230 | ||
2875fa00 | 3231 | return dentry_has_perm(cred, dentry, FILE__GETATTR); |
1da177e4 LT |
3232 | } |
3233 | ||
8f0cfa52 | 3234 | static int selinux_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 3235 | { |
6b240306 EB |
3236 | if (strcmp(name, XATTR_NAME_SELINUX)) { |
3237 | int rc = cap_inode_removexattr(dentry, name); | |
3238 | if (rc) | |
3239 | return rc; | |
3240 | ||
3241 | /* Not an attribute we recognize, so just check the | |
3242 | ordinary setattr permission. */ | |
3243 | return dentry_has_perm(current_cred(), dentry, FILE__SETATTR); | |
3244 | } | |
1da177e4 LT |
3245 | |
3246 | /* No one is allowed to remove a SELinux security label. | |
3247 | You can change the label, but all data must be labeled. */ | |
3248 | return -EACCES; | |
3249 | } | |
3250 | ||
d381d8a9 | 3251 | /* |
abc69bb6 | 3252 | * Copy the inode security context value to the user. |
d381d8a9 JM |
3253 | * |
3254 | * Permission check is handled by selinux_inode_getxattr hook. | |
3255 | */ | |
ea861dfd | 3256 | static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc) |
1da177e4 | 3257 | { |
42492594 DQ |
3258 | u32 size; |
3259 | int error; | |
3260 | char *context = NULL; | |
20cdef8d | 3261 | struct inode_security_struct *isec; |
d381d8a9 | 3262 | |
8c8570fb DK |
3263 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) |
3264 | return -EOPNOTSUPP; | |
d381d8a9 | 3265 | |
abc69bb6 SS |
3266 | /* |
3267 | * If the caller has CAP_MAC_ADMIN, then get the raw context | |
3268 | * value even if it is not defined by current policy; otherwise, | |
3269 | * use the in-core value under current policy. | |
3270 | * Use the non-auditing forms of the permission checks since | |
3271 | * getxattr may be called by unprivileged processes commonly | |
3272 | * and lack of permission just means that we fall back to the | |
3273 | * in-core context value, not a denial. | |
3274 | */ | |
20cdef8d | 3275 | isec = inode_security(inode); |
db59000a | 3276 | if (has_cap_mac_admin(false)) |
aa8e712c SS |
3277 | error = security_sid_to_context_force(&selinux_state, |
3278 | isec->sid, &context, | |
abc69bb6 SS |
3279 | &size); |
3280 | else | |
aa8e712c SS |
3281 | error = security_sid_to_context(&selinux_state, isec->sid, |
3282 | &context, &size); | |
42492594 DQ |
3283 | if (error) |
3284 | return error; | |
3285 | error = size; | |
3286 | if (alloc) { | |
3287 | *buffer = context; | |
3288 | goto out_nofree; | |
3289 | } | |
3290 | kfree(context); | |
3291 | out_nofree: | |
3292 | return error; | |
1da177e4 LT |
3293 | } |
3294 | ||
3295 | static int selinux_inode_setsecurity(struct inode *inode, const char *name, | |
828dfe1d | 3296 | const void *value, size_t size, int flags) |
1da177e4 | 3297 | { |
2c97165b | 3298 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
53e0c2aa | 3299 | struct superblock_security_struct *sbsec = inode->i_sb->s_security; |
1da177e4 LT |
3300 | u32 newsid; |
3301 | int rc; | |
3302 | ||
3303 | if (strcmp(name, XATTR_SELINUX_SUFFIX)) | |
3304 | return -EOPNOTSUPP; | |
3305 | ||
53e0c2aa OM |
3306 | if (!(sbsec->flags & SBLABEL_MNT)) |
3307 | return -EOPNOTSUPP; | |
3308 | ||
1da177e4 LT |
3309 | if (!value || !size) |
3310 | return -EACCES; | |
3311 | ||
aa8e712c SS |
3312 | rc = security_context_to_sid(&selinux_state, value, size, &newsid, |
3313 | GFP_KERNEL); | |
1da177e4 LT |
3314 | if (rc) |
3315 | return rc; | |
3316 | ||
9287aed2 | 3317 | spin_lock(&isec->lock); |
aa9c2669 | 3318 | isec->sclass = inode_mode_to_security_class(inode->i_mode); |
1da177e4 | 3319 | isec->sid = newsid; |
6f3be9f5 | 3320 | isec->initialized = LABEL_INITIALIZED; |
9287aed2 | 3321 | spin_unlock(&isec->lock); |
1da177e4 LT |
3322 | return 0; |
3323 | } | |
3324 | ||
3325 | static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) | |
3326 | { | |
3327 | const int len = sizeof(XATTR_NAME_SELINUX); | |
3328 | if (buffer && len <= buffer_size) | |
3329 | memcpy(buffer, XATTR_NAME_SELINUX, len); | |
3330 | return len; | |
3331 | } | |
3332 | ||
d6335d77 | 3333 | static void selinux_inode_getsecid(struct inode *inode, u32 *secid) |
713a04ae | 3334 | { |
e817c2f3 | 3335 | struct inode_security_struct *isec = inode_security_novalidate(inode); |
713a04ae AD |
3336 | *secid = isec->sid; |
3337 | } | |
3338 | ||
56909eb3 VG |
3339 | static int selinux_inode_copy_up(struct dentry *src, struct cred **new) |
3340 | { | |
3341 | u32 sid; | |
3342 | struct task_security_struct *tsec; | |
3343 | struct cred *new_creds = *new; | |
3344 | ||
3345 | if (new_creds == NULL) { | |
3346 | new_creds = prepare_creds(); | |
3347 | if (!new_creds) | |
3348 | return -ENOMEM; | |
3349 | } | |
3350 | ||
0c6cfa62 | 3351 | tsec = selinux_cred(new_creds); |
56909eb3 VG |
3352 | /* Get label from overlay inode and set it in create_sid */ |
3353 | selinux_inode_getsecid(d_inode(src), &sid); | |
3354 | tsec->create_sid = sid; | |
3355 | *new = new_creds; | |
3356 | return 0; | |
3357 | } | |
3358 | ||
19472b69 VG |
3359 | static int selinux_inode_copy_up_xattr(const char *name) |
3360 | { | |
3361 | /* The copy_up hook above sets the initial context on an inode, but we | |
3362 | * don't then want to overwrite it by blindly copying all the lower | |
3363 | * xattrs up. Instead, we have to filter out SELinux-related xattrs. | |
3364 | */ | |
3365 | if (strcmp(name, XATTR_NAME_SELINUX) == 0) | |
3366 | return 1; /* Discard */ | |
3367 | /* | |
3368 | * Any other attribute apart from SELINUX is not claimed, supported | |
3369 | * by selinux. | |
3370 | */ | |
3371 | return -EOPNOTSUPP; | |
3372 | } | |
3373 | ||
1da177e4 LT |
3374 | /* file security operations */ |
3375 | ||
788e7dd4 | 3376 | static int selinux_revalidate_file_permission(struct file *file, int mask) |
1da177e4 | 3377 | { |
88e67f3b | 3378 | const struct cred *cred = current_cred(); |
496ad9aa | 3379 | struct inode *inode = file_inode(file); |
1da177e4 | 3380 | |
1da177e4 LT |
3381 | /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ |
3382 | if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) | |
3383 | mask |= MAY_APPEND; | |
3384 | ||
389fb800 PM |
3385 | return file_has_perm(cred, file, |
3386 | file_mask_to_av(inode->i_mode, mask)); | |
1da177e4 LT |
3387 | } |
3388 | ||
788e7dd4 YN |
3389 | static int selinux_file_permission(struct file *file, int mask) |
3390 | { | |
496ad9aa | 3391 | struct inode *inode = file_inode(file); |
bb6c6b02 | 3392 | struct file_security_struct *fsec = selinux_file(file); |
b197367e | 3393 | struct inode_security_struct *isec; |
20dda18b SS |
3394 | u32 sid = current_sid(); |
3395 | ||
389fb800 | 3396 | if (!mask) |
788e7dd4 YN |
3397 | /* No permission to check. Existence test. */ |
3398 | return 0; | |
788e7dd4 | 3399 | |
b197367e | 3400 | isec = inode_security(inode); |
20dda18b | 3401 | if (sid == fsec->sid && fsec->isid == isec->sid && |
6b6bc620 | 3402 | fsec->pseqno == avc_policy_seqno(&selinux_state)) |
83d49856 | 3403 | /* No change since file_open check. */ |
20dda18b SS |
3404 | return 0; |
3405 | ||
788e7dd4 YN |
3406 | return selinux_revalidate_file_permission(file, mask); |
3407 | } | |
3408 | ||
1da177e4 LT |
3409 | static int selinux_file_alloc_security(struct file *file) |
3410 | { | |
3411 | return file_alloc_security(file); | |
3412 | } | |
3413 | ||
fa1aa143 JVS |
3414 | /* |
3415 | * Check whether a task has the ioctl permission and cmd | |
3416 | * operation to an inode. | |
3417 | */ | |
1d2a168a | 3418 | static int ioctl_has_perm(const struct cred *cred, struct file *file, |
fa1aa143 JVS |
3419 | u32 requested, u16 cmd) |
3420 | { | |
3421 | struct common_audit_data ad; | |
bb6c6b02 | 3422 | struct file_security_struct *fsec = selinux_file(file); |
fa1aa143 | 3423 | struct inode *inode = file_inode(file); |
20cdef8d | 3424 | struct inode_security_struct *isec; |
fa1aa143 JVS |
3425 | struct lsm_ioctlop_audit ioctl; |
3426 | u32 ssid = cred_sid(cred); | |
3427 | int rc; | |
3428 | u8 driver = cmd >> 8; | |
3429 | u8 xperm = cmd & 0xff; | |
3430 | ||
3431 | ad.type = LSM_AUDIT_DATA_IOCTL_OP; | |
3432 | ad.u.op = &ioctl; | |
3433 | ad.u.op->cmd = cmd; | |
3434 | ad.u.op->path = file->f_path; | |
3435 | ||
3436 | if (ssid != fsec->sid) { | |
6b6bc620 SS |
3437 | rc = avc_has_perm(&selinux_state, |
3438 | ssid, fsec->sid, | |
fa1aa143 JVS |
3439 | SECCLASS_FD, |
3440 | FD__USE, | |
3441 | &ad); | |
3442 | if (rc) | |
3443 | goto out; | |
3444 | } | |
3445 | ||
3446 | if (unlikely(IS_PRIVATE(inode))) | |
3447 | return 0; | |
3448 | ||
20cdef8d | 3449 | isec = inode_security(inode); |
6b6bc620 SS |
3450 | rc = avc_has_extended_perms(&selinux_state, |
3451 | ssid, isec->sid, isec->sclass, | |
3452 | requested, driver, xperm, &ad); | |
fa1aa143 JVS |
3453 | out: |
3454 | return rc; | |
3455 | } | |
3456 | ||
1da177e4 LT |
3457 | static int selinux_file_ioctl(struct file *file, unsigned int cmd, |
3458 | unsigned long arg) | |
3459 | { | |
88e67f3b | 3460 | const struct cred *cred = current_cred(); |
0b24dcb7 | 3461 | int error = 0; |
1da177e4 | 3462 | |
0b24dcb7 EP |
3463 | switch (cmd) { |
3464 | case FIONREAD: | |
3465 | /* fall through */ | |
3466 | case FIBMAP: | |
3467 | /* fall through */ | |
3468 | case FIGETBSZ: | |
3469 | /* fall through */ | |
2f99c369 | 3470 | case FS_IOC_GETFLAGS: |
0b24dcb7 | 3471 | /* fall through */ |
2f99c369 | 3472 | case FS_IOC_GETVERSION: |
0b24dcb7 EP |
3473 | error = file_has_perm(cred, file, FILE__GETATTR); |
3474 | break; | |
1da177e4 | 3475 | |
2f99c369 | 3476 | case FS_IOC_SETFLAGS: |
0b24dcb7 | 3477 | /* fall through */ |
2f99c369 | 3478 | case FS_IOC_SETVERSION: |
0b24dcb7 EP |
3479 | error = file_has_perm(cred, file, FILE__SETATTR); |
3480 | break; | |
3481 | ||
3482 | /* sys_ioctl() checks */ | |
3483 | case FIONBIO: | |
3484 | /* fall through */ | |
3485 | case FIOASYNC: | |
3486 | error = file_has_perm(cred, file, 0); | |
3487 | break; | |
1da177e4 | 3488 | |
0b24dcb7 EP |
3489 | case KDSKBENT: |
3490 | case KDSKBSENT: | |
6a9de491 | 3491 | error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, |
c1a85a00 | 3492 | CAP_OPT_NONE, true); |
0b24dcb7 EP |
3493 | break; |
3494 | ||
3495 | /* default case assumes that the command will go | |
3496 | * to the file's ioctl() function. | |
3497 | */ | |
3498 | default: | |
fa1aa143 | 3499 | error = ioctl_has_perm(cred, file, FILE__IOCTL, (u16) cmd); |
0b24dcb7 EP |
3500 | } |
3501 | return error; | |
1da177e4 LT |
3502 | } |
3503 | ||
fcaaade1 SS |
3504 | static int default_noexec; |
3505 | ||
1da177e4 LT |
3506 | static int file_map_prot_check(struct file *file, unsigned long prot, int shared) |
3507 | { | |
88e67f3b | 3508 | const struct cred *cred = current_cred(); |
be0554c9 | 3509 | u32 sid = cred_sid(cred); |
d84f4f99 | 3510 | int rc = 0; |
88e67f3b | 3511 | |
fcaaade1 | 3512 | if (default_noexec && |
892e8cac SS |
3513 | (prot & PROT_EXEC) && (!file || IS_PRIVATE(file_inode(file)) || |
3514 | (!shared && (prot & PROT_WRITE)))) { | |
1da177e4 LT |
3515 | /* |
3516 | * We are making executable an anonymous mapping or a | |
3517 | * private file mapping that will also be writable. | |
3518 | * This has an additional check. | |
3519 | */ | |
6b6bc620 SS |
3520 | rc = avc_has_perm(&selinux_state, |
3521 | sid, sid, SECCLASS_PROCESS, | |
be0554c9 | 3522 | PROCESS__EXECMEM, NULL); |
1da177e4 | 3523 | if (rc) |
d84f4f99 | 3524 | goto error; |
1da177e4 | 3525 | } |
1da177e4 LT |
3526 | |
3527 | if (file) { | |
3528 | /* read access is always possible with a mapping */ | |
3529 | u32 av = FILE__READ; | |
3530 | ||
3531 | /* write access only matters if the mapping is shared */ | |
3532 | if (shared && (prot & PROT_WRITE)) | |
3533 | av |= FILE__WRITE; | |
3534 | ||
3535 | if (prot & PROT_EXEC) | |
3536 | av |= FILE__EXECUTE; | |
3537 | ||
88e67f3b | 3538 | return file_has_perm(cred, file, av); |
1da177e4 | 3539 | } |
d84f4f99 DH |
3540 | |
3541 | error: | |
3542 | return rc; | |
1da177e4 LT |
3543 | } |
3544 | ||
e5467859 | 3545 | static int selinux_mmap_addr(unsigned long addr) |
1da177e4 | 3546 | { |
b1d9e6b0 | 3547 | int rc = 0; |
1da177e4 | 3548 | |
a2551df7 | 3549 | if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { |
98883bfd | 3550 | u32 sid = current_sid(); |
6b6bc620 SS |
3551 | rc = avc_has_perm(&selinux_state, |
3552 | sid, sid, SECCLASS_MEMPROTECT, | |
ed032189 | 3553 | MEMPROTECT__MMAP_ZERO, NULL); |
84336d1a EP |
3554 | } |
3555 | ||
98883bfd | 3556 | return rc; |
e5467859 | 3557 | } |
1da177e4 | 3558 | |
e5467859 AV |
3559 | static int selinux_mmap_file(struct file *file, unsigned long reqprot, |
3560 | unsigned long prot, unsigned long flags) | |
3561 | { | |
3ba4bf5f SS |
3562 | struct common_audit_data ad; |
3563 | int rc; | |
3564 | ||
3565 | if (file) { | |
3566 | ad.type = LSM_AUDIT_DATA_FILE; | |
3567 | ad.u.file = file; | |
3568 | rc = inode_has_perm(current_cred(), file_inode(file), | |
3569 | FILE__MAP, &ad); | |
3570 | if (rc) | |
3571 | return rc; | |
3572 | } | |
3573 | ||
aa8e712c | 3574 | if (selinux_state.checkreqprot) |
1da177e4 LT |
3575 | prot = reqprot; |
3576 | ||
3577 | return file_map_prot_check(file, prot, | |
3578 | (flags & MAP_TYPE) == MAP_SHARED); | |
3579 | } | |
3580 | ||
3581 | static int selinux_file_mprotect(struct vm_area_struct *vma, | |
3582 | unsigned long reqprot, | |
3583 | unsigned long prot) | |
3584 | { | |
88e67f3b | 3585 | const struct cred *cred = current_cred(); |
be0554c9 | 3586 | u32 sid = cred_sid(cred); |
1da177e4 | 3587 | |
aa8e712c | 3588 | if (selinux_state.checkreqprot) |
1da177e4 LT |
3589 | prot = reqprot; |
3590 | ||
fcaaade1 SS |
3591 | if (default_noexec && |
3592 | (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { | |
d541bbee | 3593 | int rc = 0; |
db4c9641 SS |
3594 | if (vma->vm_start >= vma->vm_mm->start_brk && |
3595 | vma->vm_end <= vma->vm_mm->brk) { | |
6b6bc620 SS |
3596 | rc = avc_has_perm(&selinux_state, |
3597 | sid, sid, SECCLASS_PROCESS, | |
be0554c9 | 3598 | PROCESS__EXECHEAP, NULL); |
db4c9641 | 3599 | } else if (!vma->vm_file && |
c2316dbf SS |
3600 | ((vma->vm_start <= vma->vm_mm->start_stack && |
3601 | vma->vm_end >= vma->vm_mm->start_stack) || | |
d17af505 | 3602 | vma_is_stack_for_current(vma))) { |
6b6bc620 SS |
3603 | rc = avc_has_perm(&selinux_state, |
3604 | sid, sid, SECCLASS_PROCESS, | |
be0554c9 | 3605 | PROCESS__EXECSTACK, NULL); |
db4c9641 SS |
3606 | } else if (vma->vm_file && vma->anon_vma) { |
3607 | /* | |
3608 | * We are making executable a file mapping that has | |
3609 | * had some COW done. Since pages might have been | |
3610 | * written, check ability to execute the possibly | |
3611 | * modified content. This typically should only | |
3612 | * occur for text relocations. | |
3613 | */ | |
d84f4f99 | 3614 | rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); |
db4c9641 | 3615 | } |