Commit | Line | Data |
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3323eec9 MZ |
1 | /* |
2 | * Copyright (C) 2008 IBM Corporation | |
3 | * Author: Mimi Zohar <zohar@us.ibm.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation, version 2 of the License. | |
8 | * | |
9 | * ima_policy.c | |
2bb930ab | 10 | * - initialize default measure policy rules |
3323eec9 MZ |
11 | * |
12 | */ | |
13 | #include <linux/module.h> | |
14 | #include <linux/list.h> | |
3323eec9 MZ |
15 | #include <linux/security.h> |
16 | #include <linux/magic.h> | |
4af4662f | 17 | #include <linux/parser.h> |
5a0e3ad6 | 18 | #include <linux/slab.h> |
85865c1f | 19 | #include <linux/genhd.h> |
3323eec9 MZ |
20 | |
21 | #include "ima.h" | |
22 | ||
23 | /* flags definitions */ | |
2bb930ab DK |
24 | #define IMA_FUNC 0x0001 |
25 | #define IMA_MASK 0x0002 | |
3323eec9 MZ |
26 | #define IMA_FSMAGIC 0x0004 |
27 | #define IMA_UID 0x0008 | |
07f6a794 | 28 | #define IMA_FOWNER 0x0010 |
85865c1f | 29 | #define IMA_FSUUID 0x0020 |
3323eec9 | 30 | |
45e2472e DK |
31 | #define UNKNOWN 0 |
32 | #define MEASURE 0x0001 /* same as IMA_MEASURE */ | |
33 | #define DONT_MEASURE 0x0002 | |
34 | #define APPRAISE 0x0004 /* same as IMA_APPRAISE */ | |
35 | #define DONT_APPRAISE 0x0008 | |
e7c568e0 | 36 | #define AUDIT 0x0040 |
4af4662f | 37 | |
a756024e RS |
38 | int ima_policy_flag; |
39 | ||
4af4662f MZ |
40 | #define MAX_LSM_RULES 6 |
41 | enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, | |
42 | LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE | |
43 | }; | |
3323eec9 | 44 | |
07f6a794 | 45 | struct ima_rule_entry { |
3323eec9 | 46 | struct list_head list; |
2fe5d6de | 47 | int action; |
3323eec9 MZ |
48 | unsigned int flags; |
49 | enum ima_hooks func; | |
50 | int mask; | |
51 | unsigned long fsmagic; | |
85865c1f | 52 | u8 fsuuid[16]; |
8b94eea4 | 53 | kuid_t uid; |
88265322 | 54 | kuid_t fowner; |
4af4662f MZ |
55 | struct { |
56 | void *rule; /* LSM file metadata specific */ | |
7163a993 | 57 | void *args_p; /* audit value */ |
4af4662f MZ |
58 | int type; /* audit type */ |
59 | } lsm[MAX_LSM_RULES]; | |
3323eec9 MZ |
60 | }; |
61 | ||
5789ba3b EP |
62 | /* |
63 | * Without LSM specific knowledge, the default policy can only be | |
07f6a794 | 64 | * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner |
4af4662f | 65 | */ |
5789ba3b EP |
66 | |
67 | /* | |
68 | * The minimum rule set to allow for full TCB coverage. Measures all files | |
69 | * opened or mmap for exec and everything read by root. Dangerous because | |
70 | * normal users can easily run the machine out of memory simply building | |
71 | * and running executables. | |
72 | */ | |
07f6a794 | 73 | static struct ima_rule_entry default_rules[] = { |
2bb930ab DK |
74 | {.action = DONT_MEASURE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC}, |
75 | {.action = DONT_MEASURE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC}, | |
76 | {.action = DONT_MEASURE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC}, | |
77 | {.action = DONT_MEASURE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC}, | |
78 | {.action = DONT_MEASURE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC}, | |
79 | {.action = DONT_MEASURE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC}, | |
80 | {.action = DONT_MEASURE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC}, | |
81 | {.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC}, | |
82 | {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC, | |
3323eec9 | 83 | .flags = IMA_FUNC | IMA_MASK}, |
2bb930ab | 84 | {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC, |
3323eec9 | 85 | .flags = IMA_FUNC | IMA_MASK}, |
2bb930ab | 86 | {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ, .uid = GLOBAL_ROOT_UID, |
5789ba3b | 87 | .flags = IMA_FUNC | IMA_MASK | IMA_UID}, |
2bb930ab | 88 | {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC}, |
5a9196d7 | 89 | {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC}, |
3323eec9 MZ |
90 | }; |
91 | ||
07f6a794 | 92 | static struct ima_rule_entry default_appraise_rules[] = { |
2bb930ab DK |
93 | {.action = DONT_APPRAISE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC}, |
94 | {.action = DONT_APPRAISE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC}, | |
95 | {.action = DONT_APPRAISE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC}, | |
96 | {.action = DONT_APPRAISE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC}, | |
97 | {.action = DONT_APPRAISE, .fsmagic = RAMFS_MAGIC, .flags = IMA_FSMAGIC}, | |
98 | {.action = DONT_APPRAISE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC}, | |
99 | {.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC}, | |
100 | {.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC}, | |
101 | {.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC}, | |
102 | {.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC}, | |
c57782c1 | 103 | #ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT |
2bb930ab | 104 | {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .flags = IMA_FOWNER}, |
c57782c1 DK |
105 | #else |
106 | /* force signature */ | |
107 | {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, | |
108 | .flags = IMA_FOWNER | IMA_DIGSIG_REQUIRED}, | |
109 | #endif | |
07f6a794 MZ |
110 | }; |
111 | ||
112 | static LIST_HEAD(ima_default_rules); | |
113 | static LIST_HEAD(ima_policy_rules); | |
114 | static struct list_head *ima_rules; | |
3323eec9 | 115 | |
07f6a794 | 116 | static DEFINE_MUTEX(ima_rules_mutex); |
4af4662f | 117 | |
5789ba3b | 118 | static bool ima_use_tcb __initdata; |
07f6a794 | 119 | static int __init default_measure_policy_setup(char *str) |
5789ba3b EP |
120 | { |
121 | ima_use_tcb = 1; | |
122 | return 1; | |
123 | } | |
07f6a794 MZ |
124 | __setup("ima_tcb", default_measure_policy_setup); |
125 | ||
126 | static bool ima_use_appraise_tcb __initdata; | |
127 | static int __init default_appraise_policy_setup(char *str) | |
128 | { | |
129 | ima_use_appraise_tcb = 1; | |
130 | return 1; | |
131 | } | |
132 | __setup("ima_appraise_tcb", default_appraise_policy_setup); | |
5789ba3b | 133 | |
2bb930ab | 134 | /* |
7163a993 MZ |
135 | * Although the IMA policy does not change, the LSM policy can be |
136 | * reloaded, leaving the IMA LSM based rules referring to the old, | |
137 | * stale LSM policy. | |
138 | * | |
2bb930ab | 139 | * Update the IMA LSM based rules to reflect the reloaded LSM policy. |
7163a993 MZ |
140 | * We assume the rules still exist; and BUG_ON() if they don't. |
141 | */ | |
142 | static void ima_lsm_update_rules(void) | |
143 | { | |
144 | struct ima_rule_entry *entry, *tmp; | |
145 | int result; | |
146 | int i; | |
147 | ||
148 | mutex_lock(&ima_rules_mutex); | |
149 | list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) { | |
150 | for (i = 0; i < MAX_LSM_RULES; i++) { | |
151 | if (!entry->lsm[i].rule) | |
152 | continue; | |
153 | result = security_filter_rule_init(entry->lsm[i].type, | |
154 | Audit_equal, | |
155 | entry->lsm[i].args_p, | |
156 | &entry->lsm[i].rule); | |
157 | BUG_ON(!entry->lsm[i].rule); | |
158 | } | |
159 | } | |
160 | mutex_unlock(&ima_rules_mutex); | |
161 | } | |
162 | ||
3323eec9 MZ |
163 | /** |
164 | * ima_match_rules - determine whether an inode matches the measure rule. | |
165 | * @rule: a pointer to a rule | |
166 | * @inode: a pointer to an inode | |
167 | * @func: LIM hook identifier | |
168 | * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) | |
169 | * | |
170 | * Returns true on rule match, false on failure. | |
171 | */ | |
07f6a794 | 172 | static bool ima_match_rules(struct ima_rule_entry *rule, |
3323eec9 MZ |
173 | struct inode *inode, enum ima_hooks func, int mask) |
174 | { | |
175 | struct task_struct *tsk = current; | |
3db59dd9 | 176 | const struct cred *cred = current_cred(); |
4af4662f | 177 | int i; |
3323eec9 | 178 | |
09b1148e DK |
179 | if ((rule->flags & IMA_FUNC) && |
180 | (rule->func != func && func != POST_SETATTR)) | |
3323eec9 | 181 | return false; |
09b1148e DK |
182 | if ((rule->flags & IMA_MASK) && |
183 | (rule->mask != mask && func != POST_SETATTR)) | |
3323eec9 MZ |
184 | return false; |
185 | if ((rule->flags & IMA_FSMAGIC) | |
186 | && rule->fsmagic != inode->i_sb->s_magic) | |
187 | return false; | |
85865c1f | 188 | if ((rule->flags & IMA_FSUUID) && |
446d64e3 | 189 | memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid))) |
85865c1f | 190 | return false; |
8b94eea4 | 191 | if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid)) |
3323eec9 | 192 | return false; |
88265322 | 193 | if ((rule->flags & IMA_FOWNER) && !uid_eq(rule->fowner, inode->i_uid)) |
07f6a794 | 194 | return false; |
4af4662f | 195 | for (i = 0; i < MAX_LSM_RULES; i++) { |
53fc0e22 | 196 | int rc = 0; |
4af4662f | 197 | u32 osid, sid; |
7163a993 | 198 | int retried = 0; |
4af4662f MZ |
199 | |
200 | if (!rule->lsm[i].rule) | |
201 | continue; | |
7163a993 | 202 | retry: |
4af4662f MZ |
203 | switch (i) { |
204 | case LSM_OBJ_USER: | |
205 | case LSM_OBJ_ROLE: | |
206 | case LSM_OBJ_TYPE: | |
207 | security_inode_getsecid(inode, &osid); | |
208 | rc = security_filter_rule_match(osid, | |
209 | rule->lsm[i].type, | |
53fc0e22 | 210 | Audit_equal, |
4af4662f MZ |
211 | rule->lsm[i].rule, |
212 | NULL); | |
213 | break; | |
214 | case LSM_SUBJ_USER: | |
215 | case LSM_SUBJ_ROLE: | |
216 | case LSM_SUBJ_TYPE: | |
217 | security_task_getsecid(tsk, &sid); | |
218 | rc = security_filter_rule_match(sid, | |
219 | rule->lsm[i].type, | |
53fc0e22 | 220 | Audit_equal, |
4af4662f MZ |
221 | rule->lsm[i].rule, |
222 | NULL); | |
223 | default: | |
224 | break; | |
225 | } | |
7163a993 MZ |
226 | if ((rc < 0) && (!retried)) { |
227 | retried = 1; | |
228 | ima_lsm_update_rules(); | |
229 | goto retry; | |
2bb930ab | 230 | } |
4af4662f MZ |
231 | if (!rc) |
232 | return false; | |
233 | } | |
3323eec9 MZ |
234 | return true; |
235 | } | |
236 | ||
d79d72e0 MZ |
237 | /* |
238 | * In addition to knowing that we need to appraise the file in general, | |
5a73fcfa | 239 | * we need to differentiate between calling hooks, for hook specific rules. |
d79d72e0 | 240 | */ |
5a73fcfa | 241 | static int get_subaction(struct ima_rule_entry *rule, int func) |
d79d72e0 | 242 | { |
5a73fcfa MZ |
243 | if (!(rule->flags & IMA_FUNC)) |
244 | return IMA_FILE_APPRAISE; | |
245 | ||
2bb930ab | 246 | switch (func) { |
d79d72e0 MZ |
247 | case MMAP_CHECK: |
248 | return IMA_MMAP_APPRAISE; | |
249 | case BPRM_CHECK: | |
250 | return IMA_BPRM_APPRAISE; | |
251 | case MODULE_CHECK: | |
252 | return IMA_MODULE_APPRAISE; | |
5a9196d7 MZ |
253 | case FIRMWARE_CHECK: |
254 | return IMA_FIRMWARE_APPRAISE; | |
d79d72e0 MZ |
255 | case FILE_CHECK: |
256 | default: | |
257 | return IMA_FILE_APPRAISE; | |
258 | } | |
259 | } | |
260 | ||
3323eec9 MZ |
261 | /** |
262 | * ima_match_policy - decision based on LSM and other conditions | |
263 | * @inode: pointer to an inode for which the policy decision is being made | |
264 | * @func: IMA hook identifier | |
265 | * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) | |
266 | * | |
267 | * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type) | |
268 | * conditions. | |
269 | * | |
270 | * (There is no need for locking when walking the policy list, | |
271 | * as elements in the list are never deleted, nor does the list | |
272 | * change.) | |
273 | */ | |
2fe5d6de MZ |
274 | int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, |
275 | int flags) | |
3323eec9 | 276 | { |
07f6a794 | 277 | struct ima_rule_entry *entry; |
2fe5d6de | 278 | int action = 0, actmask = flags | (flags << 1); |
3323eec9 | 279 | |
07f6a794 | 280 | list_for_each_entry(entry, ima_rules, list) { |
3323eec9 | 281 | |
2fe5d6de MZ |
282 | if (!(entry->action & actmask)) |
283 | continue; | |
284 | ||
285 | if (!ima_match_rules(entry, inode, func, mask)) | |
286 | continue; | |
3323eec9 | 287 | |
0e5a247c DK |
288 | action |= entry->flags & IMA_ACTION_FLAGS; |
289 | ||
45e2472e | 290 | action |= entry->action & IMA_DO_MASK; |
d79d72e0 | 291 | if (entry->action & IMA_APPRAISE) |
5a73fcfa | 292 | action |= get_subaction(entry, func); |
d79d72e0 | 293 | |
45e2472e DK |
294 | if (entry->action & IMA_DO_MASK) |
295 | actmask &= ~(entry->action | entry->action << 1); | |
296 | else | |
297 | actmask &= ~(entry->action | entry->action >> 1); | |
3323eec9 | 298 | |
2fe5d6de MZ |
299 | if (!actmask) |
300 | break; | |
3323eec9 | 301 | } |
2fe5d6de MZ |
302 | |
303 | return action; | |
3323eec9 MZ |
304 | } |
305 | ||
a756024e RS |
306 | /* |
307 | * Initialize the ima_policy_flag variable based on the currently | |
308 | * loaded policy. Based on this flag, the decision to short circuit | |
309 | * out of a function or not call the function in the first place | |
310 | * can be made earlier. | |
311 | */ | |
312 | void ima_update_policy_flag(void) | |
313 | { | |
314 | struct ima_rule_entry *entry; | |
315 | ||
316 | ima_policy_flag = 0; | |
317 | list_for_each_entry(entry, ima_rules, list) { | |
318 | if (entry->action & IMA_DO_MASK) | |
319 | ima_policy_flag |= entry->action; | |
320 | } | |
321 | ||
322 | if (!ima_appraise) | |
323 | ima_policy_flag &= ~IMA_APPRAISE; | |
324 | } | |
325 | ||
3323eec9 MZ |
326 | /** |
327 | * ima_init_policy - initialize the default measure rules. | |
328 | * | |
07f6a794 MZ |
329 | * ima_rules points to either the ima_default_rules or the |
330 | * the new ima_policy_rules. | |
3323eec9 | 331 | */ |
932995f0 | 332 | void __init ima_init_policy(void) |
3323eec9 | 333 | { |
07f6a794 | 334 | int i, measure_entries, appraise_entries; |
5789ba3b EP |
335 | |
336 | /* if !ima_use_tcb set entries = 0 so we load NO default rules */ | |
07f6a794 MZ |
337 | measure_entries = ima_use_tcb ? ARRAY_SIZE(default_rules) : 0; |
338 | appraise_entries = ima_use_appraise_tcb ? | |
339 | ARRAY_SIZE(default_appraise_rules) : 0; | |
2bb930ab | 340 | |
07f6a794 MZ |
341 | for (i = 0; i < measure_entries + appraise_entries; i++) { |
342 | if (i < measure_entries) | |
343 | list_add_tail(&default_rules[i].list, | |
344 | &ima_default_rules); | |
345 | else { | |
346 | int j = i - measure_entries; | |
347 | ||
348 | list_add_tail(&default_appraise_rules[j].list, | |
349 | &ima_default_rules); | |
350 | } | |
351 | } | |
352 | ||
353 | ima_rules = &ima_default_rules; | |
3323eec9 | 354 | } |
4af4662f MZ |
355 | |
356 | /** | |
357 | * ima_update_policy - update default_rules with new measure rules | |
358 | * | |
359 | * Called on file .release to update the default rules with a complete new | |
360 | * policy. Once updated, the policy is locked, no additional rules can be | |
361 | * added to the policy. | |
362 | */ | |
363 | void ima_update_policy(void) | |
364 | { | |
0716abbb DK |
365 | ima_rules = &ima_policy_rules; |
366 | ima_update_policy_flag(); | |
4af4662f MZ |
367 | } |
368 | ||
369 | enum { | |
370 | Opt_err = -1, | |
371 | Opt_measure = 1, Opt_dont_measure, | |
07f6a794 | 372 | Opt_appraise, Opt_dont_appraise, |
e7c568e0 | 373 | Opt_audit, |
4af4662f MZ |
374 | Opt_obj_user, Opt_obj_role, Opt_obj_type, |
375 | Opt_subj_user, Opt_subj_role, Opt_subj_type, | |
0e5a247c | 376 | Opt_func, Opt_mask, Opt_fsmagic, Opt_uid, Opt_fowner, |
f9b2a735 | 377 | Opt_appraise_type, Opt_fsuuid, Opt_permit_directio |
4af4662f MZ |
378 | }; |
379 | ||
380 | static match_table_t policy_tokens = { | |
381 | {Opt_measure, "measure"}, | |
382 | {Opt_dont_measure, "dont_measure"}, | |
07f6a794 MZ |
383 | {Opt_appraise, "appraise"}, |
384 | {Opt_dont_appraise, "dont_appraise"}, | |
e7c568e0 | 385 | {Opt_audit, "audit"}, |
4af4662f MZ |
386 | {Opt_obj_user, "obj_user=%s"}, |
387 | {Opt_obj_role, "obj_role=%s"}, | |
388 | {Opt_obj_type, "obj_type=%s"}, | |
389 | {Opt_subj_user, "subj_user=%s"}, | |
390 | {Opt_subj_role, "subj_role=%s"}, | |
391 | {Opt_subj_type, "subj_type=%s"}, | |
392 | {Opt_func, "func=%s"}, | |
393 | {Opt_mask, "mask=%s"}, | |
394 | {Opt_fsmagic, "fsmagic=%s"}, | |
85865c1f | 395 | {Opt_fsuuid, "fsuuid=%s"}, |
4af4662f | 396 | {Opt_uid, "uid=%s"}, |
07f6a794 | 397 | {Opt_fowner, "fowner=%s"}, |
0e5a247c | 398 | {Opt_appraise_type, "appraise_type=%s"}, |
f9b2a735 | 399 | {Opt_permit_directio, "permit_directio"}, |
4af4662f MZ |
400 | {Opt_err, NULL} |
401 | }; | |
402 | ||
07f6a794 | 403 | static int ima_lsm_rule_init(struct ima_rule_entry *entry, |
7163a993 | 404 | substring_t *args, int lsm_rule, int audit_type) |
4af4662f MZ |
405 | { |
406 | int result; | |
407 | ||
7b62e162 EP |
408 | if (entry->lsm[lsm_rule].rule) |
409 | return -EINVAL; | |
410 | ||
7163a993 MZ |
411 | entry->lsm[lsm_rule].args_p = match_strdup(args); |
412 | if (!entry->lsm[lsm_rule].args_p) | |
413 | return -ENOMEM; | |
414 | ||
4af4662f MZ |
415 | entry->lsm[lsm_rule].type = audit_type; |
416 | result = security_filter_rule_init(entry->lsm[lsm_rule].type, | |
7163a993 MZ |
417 | Audit_equal, |
418 | entry->lsm[lsm_rule].args_p, | |
4af4662f | 419 | &entry->lsm[lsm_rule].rule); |
7163a993 MZ |
420 | if (!entry->lsm[lsm_rule].rule) { |
421 | kfree(entry->lsm[lsm_rule].args_p); | |
867c2026 | 422 | return -EINVAL; |
7163a993 MZ |
423 | } |
424 | ||
4af4662f MZ |
425 | return result; |
426 | } | |
427 | ||
2f1506cd EP |
428 | static void ima_log_string(struct audit_buffer *ab, char *key, char *value) |
429 | { | |
430 | audit_log_format(ab, "%s=", key); | |
431 | audit_log_untrustedstring(ab, value); | |
432 | audit_log_format(ab, " "); | |
433 | } | |
434 | ||
07f6a794 | 435 | static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) |
4af4662f MZ |
436 | { |
437 | struct audit_buffer *ab; | |
438 | char *p; | |
439 | int result = 0; | |
440 | ||
523979ad | 441 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE); |
4af4662f | 442 | |
8b94eea4 | 443 | entry->uid = INVALID_UID; |
88265322 | 444 | entry->fowner = INVALID_UID; |
b9035b1f | 445 | entry->action = UNKNOWN; |
28ef4002 | 446 | while ((p = strsep(&rule, " \t")) != NULL) { |
4af4662f MZ |
447 | substring_t args[MAX_OPT_ARGS]; |
448 | int token; | |
449 | unsigned long lnum; | |
450 | ||
451 | if (result < 0) | |
452 | break; | |
28ef4002 EP |
453 | if ((*p == '\0') || (*p == ' ') || (*p == '\t')) |
454 | continue; | |
4af4662f MZ |
455 | token = match_token(p, policy_tokens, args); |
456 | switch (token) { | |
457 | case Opt_measure: | |
2f1506cd | 458 | ima_log_string(ab, "action", "measure"); |
7b62e162 EP |
459 | |
460 | if (entry->action != UNKNOWN) | |
461 | result = -EINVAL; | |
462 | ||
4af4662f MZ |
463 | entry->action = MEASURE; |
464 | break; | |
465 | case Opt_dont_measure: | |
2f1506cd | 466 | ima_log_string(ab, "action", "dont_measure"); |
7b62e162 EP |
467 | |
468 | if (entry->action != UNKNOWN) | |
469 | result = -EINVAL; | |
470 | ||
4af4662f MZ |
471 | entry->action = DONT_MEASURE; |
472 | break; | |
07f6a794 MZ |
473 | case Opt_appraise: |
474 | ima_log_string(ab, "action", "appraise"); | |
475 | ||
476 | if (entry->action != UNKNOWN) | |
477 | result = -EINVAL; | |
478 | ||
479 | entry->action = APPRAISE; | |
480 | break; | |
481 | case Opt_dont_appraise: | |
482 | ima_log_string(ab, "action", "dont_appraise"); | |
483 | ||
484 | if (entry->action != UNKNOWN) | |
485 | result = -EINVAL; | |
486 | ||
487 | entry->action = DONT_APPRAISE; | |
488 | break; | |
e7c568e0 PM |
489 | case Opt_audit: |
490 | ima_log_string(ab, "action", "audit"); | |
491 | ||
492 | if (entry->action != UNKNOWN) | |
493 | result = -EINVAL; | |
494 | ||
495 | entry->action = AUDIT; | |
496 | break; | |
4af4662f | 497 | case Opt_func: |
2f1506cd | 498 | ima_log_string(ab, "func", args[0].from); |
7b62e162 EP |
499 | |
500 | if (entry->func) | |
07f6a794 | 501 | result = -EINVAL; |
7b62e162 | 502 | |
1e93d005 MZ |
503 | if (strcmp(args[0].from, "FILE_CHECK") == 0) |
504 | entry->func = FILE_CHECK; | |
505 | /* PATH_CHECK is for backwards compat */ | |
506 | else if (strcmp(args[0].from, "PATH_CHECK") == 0) | |
507 | entry->func = FILE_CHECK; | |
fdf90729 MZ |
508 | else if (strcmp(args[0].from, "MODULE_CHECK") == 0) |
509 | entry->func = MODULE_CHECK; | |
5a9196d7 MZ |
510 | else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0) |
511 | entry->func = FIRMWARE_CHECK; | |
16cac49f MZ |
512 | else if ((strcmp(args[0].from, "FILE_MMAP") == 0) |
513 | || (strcmp(args[0].from, "MMAP_CHECK") == 0)) | |
514 | entry->func = MMAP_CHECK; | |
4af4662f MZ |
515 | else if (strcmp(args[0].from, "BPRM_CHECK") == 0) |
516 | entry->func = BPRM_CHECK; | |
517 | else | |
518 | result = -EINVAL; | |
519 | if (!result) | |
520 | entry->flags |= IMA_FUNC; | |
521 | break; | |
522 | case Opt_mask: | |
2f1506cd | 523 | ima_log_string(ab, "mask", args[0].from); |
7b62e162 EP |
524 | |
525 | if (entry->mask) | |
526 | result = -EINVAL; | |
527 | ||
4af4662f MZ |
528 | if ((strcmp(args[0].from, "MAY_EXEC")) == 0) |
529 | entry->mask = MAY_EXEC; | |
530 | else if (strcmp(args[0].from, "MAY_WRITE") == 0) | |
531 | entry->mask = MAY_WRITE; | |
532 | else if (strcmp(args[0].from, "MAY_READ") == 0) | |
533 | entry->mask = MAY_READ; | |
534 | else if (strcmp(args[0].from, "MAY_APPEND") == 0) | |
535 | entry->mask = MAY_APPEND; | |
536 | else | |
537 | result = -EINVAL; | |
538 | if (!result) | |
539 | entry->flags |= IMA_MASK; | |
540 | break; | |
541 | case Opt_fsmagic: | |
2f1506cd | 542 | ima_log_string(ab, "fsmagic", args[0].from); |
7b62e162 EP |
543 | |
544 | if (entry->fsmagic) { | |
545 | result = -EINVAL; | |
546 | break; | |
547 | } | |
548 | ||
2bb930ab | 549 | result = kstrtoul(args[0].from, 16, &entry->fsmagic); |
4af4662f MZ |
550 | if (!result) |
551 | entry->flags |= IMA_FSMAGIC; | |
552 | break; | |
85865c1f DK |
553 | case Opt_fsuuid: |
554 | ima_log_string(ab, "fsuuid", args[0].from); | |
555 | ||
556 | if (memchr_inv(entry->fsuuid, 0x00, | |
446d64e3 | 557 | sizeof(entry->fsuuid))) { |
85865c1f DK |
558 | result = -EINVAL; |
559 | break; | |
560 | } | |
561 | ||
446d64e3 MZ |
562 | result = blk_part_pack_uuid(args[0].from, |
563 | entry->fsuuid); | |
564 | if (!result) | |
565 | entry->flags |= IMA_FSUUID; | |
85865c1f | 566 | break; |
4af4662f | 567 | case Opt_uid: |
2f1506cd | 568 | ima_log_string(ab, "uid", args[0].from); |
7b62e162 | 569 | |
8b94eea4 | 570 | if (uid_valid(entry->uid)) { |
7b62e162 EP |
571 | result = -EINVAL; |
572 | break; | |
573 | } | |
574 | ||
29707b20 | 575 | result = kstrtoul(args[0].from, 10, &lnum); |
4af4662f | 576 | if (!result) { |
8b94eea4 EB |
577 | entry->uid = make_kuid(current_user_ns(), (uid_t)lnum); |
578 | if (!uid_valid(entry->uid) || (((uid_t)lnum) != lnum)) | |
4af4662f MZ |
579 | result = -EINVAL; |
580 | else | |
581 | entry->flags |= IMA_UID; | |
582 | } | |
583 | break; | |
07f6a794 MZ |
584 | case Opt_fowner: |
585 | ima_log_string(ab, "fowner", args[0].from); | |
586 | ||
88265322 | 587 | if (uid_valid(entry->fowner)) { |
07f6a794 MZ |
588 | result = -EINVAL; |
589 | break; | |
590 | } | |
591 | ||
29707b20 | 592 | result = kstrtoul(args[0].from, 10, &lnum); |
07f6a794 | 593 | if (!result) { |
88265322 LT |
594 | entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum); |
595 | if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum)) | |
07f6a794 MZ |
596 | result = -EINVAL; |
597 | else | |
598 | entry->flags |= IMA_FOWNER; | |
599 | } | |
600 | break; | |
4af4662f | 601 | case Opt_obj_user: |
2f1506cd | 602 | ima_log_string(ab, "obj_user", args[0].from); |
7163a993 | 603 | result = ima_lsm_rule_init(entry, args, |
4af4662f MZ |
604 | LSM_OBJ_USER, |
605 | AUDIT_OBJ_USER); | |
606 | break; | |
607 | case Opt_obj_role: | |
2f1506cd | 608 | ima_log_string(ab, "obj_role", args[0].from); |
7163a993 | 609 | result = ima_lsm_rule_init(entry, args, |
4af4662f MZ |
610 | LSM_OBJ_ROLE, |
611 | AUDIT_OBJ_ROLE); | |
612 | break; | |
613 | case Opt_obj_type: | |
2f1506cd | 614 | ima_log_string(ab, "obj_type", args[0].from); |
7163a993 | 615 | result = ima_lsm_rule_init(entry, args, |
4af4662f MZ |
616 | LSM_OBJ_TYPE, |
617 | AUDIT_OBJ_TYPE); | |
618 | break; | |
619 | case Opt_subj_user: | |
2f1506cd | 620 | ima_log_string(ab, "subj_user", args[0].from); |
7163a993 | 621 | result = ima_lsm_rule_init(entry, args, |
4af4662f MZ |
622 | LSM_SUBJ_USER, |
623 | AUDIT_SUBJ_USER); | |
624 | break; | |
625 | case Opt_subj_role: | |
2f1506cd | 626 | ima_log_string(ab, "subj_role", args[0].from); |
7163a993 | 627 | result = ima_lsm_rule_init(entry, args, |
4af4662f MZ |
628 | LSM_SUBJ_ROLE, |
629 | AUDIT_SUBJ_ROLE); | |
630 | break; | |
631 | case Opt_subj_type: | |
2f1506cd | 632 | ima_log_string(ab, "subj_type", args[0].from); |
7163a993 | 633 | result = ima_lsm_rule_init(entry, args, |
4af4662f MZ |
634 | LSM_SUBJ_TYPE, |
635 | AUDIT_SUBJ_TYPE); | |
636 | break; | |
0e5a247c DK |
637 | case Opt_appraise_type: |
638 | if (entry->action != APPRAISE) { | |
639 | result = -EINVAL; | |
640 | break; | |
641 | } | |
642 | ||
643 | ima_log_string(ab, "appraise_type", args[0].from); | |
644 | if ((strcmp(args[0].from, "imasig")) == 0) | |
645 | entry->flags |= IMA_DIGSIG_REQUIRED; | |
646 | else | |
647 | result = -EINVAL; | |
648 | break; | |
f9b2a735 MZ |
649 | case Opt_permit_directio: |
650 | entry->flags |= IMA_PERMIT_DIRECTIO; | |
651 | break; | |
4af4662f | 652 | case Opt_err: |
2f1506cd | 653 | ima_log_string(ab, "UNKNOWN", p); |
e9d393bf | 654 | result = -EINVAL; |
4af4662f MZ |
655 | break; |
656 | } | |
657 | } | |
7b62e162 | 658 | if (!result && (entry->action == UNKNOWN)) |
4af4662f | 659 | result = -EINVAL; |
a7f2a366 MZ |
660 | else if (entry->func == MODULE_CHECK) |
661 | ima_appraise |= IMA_APPRAISE_MODULES; | |
5a9196d7 MZ |
662 | else if (entry->func == FIRMWARE_CHECK) |
663 | ima_appraise |= IMA_APPRAISE_FIRMWARE; | |
b0d5de4d | 664 | audit_log_format(ab, "res=%d", !result); |
4af4662f MZ |
665 | audit_log_end(ab); |
666 | return result; | |
667 | } | |
668 | ||
669 | /** | |
07f6a794 | 670 | * ima_parse_add_rule - add a rule to ima_policy_rules |
4af4662f MZ |
671 | * @rule - ima measurement policy rule |
672 | * | |
673 | * Uses a mutex to protect the policy list from multiple concurrent writers. | |
6ccd0456 | 674 | * Returns the length of the rule parsed, an error code on failure |
4af4662f | 675 | */ |
6ccd0456 | 676 | ssize_t ima_parse_add_rule(char *rule) |
4af4662f | 677 | { |
52a13284 | 678 | static const char op[] = "update_policy"; |
6ccd0456 | 679 | char *p; |
07f6a794 | 680 | struct ima_rule_entry *entry; |
6ccd0456 | 681 | ssize_t result, len; |
4af4662f MZ |
682 | int audit_info = 0; |
683 | ||
272a6e90 DK |
684 | p = strsep(&rule, "\n"); |
685 | len = strlen(p) + 1; | |
7178784f | 686 | p += strspn(p, " \t"); |
272a6e90 | 687 | |
7178784f | 688 | if (*p == '#' || *p == '\0') |
272a6e90 DK |
689 | return len; |
690 | ||
4af4662f MZ |
691 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
692 | if (!entry) { | |
693 | integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, | |
694 | NULL, op, "-ENOMEM", -ENOMEM, audit_info); | |
695 | return -ENOMEM; | |
696 | } | |
697 | ||
698 | INIT_LIST_HEAD(&entry->list); | |
699 | ||
6ccd0456 | 700 | result = ima_parse_rule(p, entry); |
7233e3ee | 701 | if (result) { |
4af4662f | 702 | kfree(entry); |
523979ad | 703 | integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, |
7e9001f6 | 704 | NULL, op, "invalid-policy", result, |
523979ad | 705 | audit_info); |
7233e3ee | 706 | return result; |
523979ad | 707 | } |
7233e3ee | 708 | |
07f6a794 MZ |
709 | mutex_lock(&ima_rules_mutex); |
710 | list_add_tail(&entry->list, &ima_policy_rules); | |
711 | mutex_unlock(&ima_rules_mutex); | |
7233e3ee EP |
712 | |
713 | return len; | |
4af4662f MZ |
714 | } |
715 | ||
716 | /* ima_delete_rules called to cleanup invalid policy */ | |
64c61d80 | 717 | void ima_delete_rules(void) |
4af4662f | 718 | { |
07f6a794 | 719 | struct ima_rule_entry *entry, *tmp; |
7163a993 | 720 | int i; |
4af4662f | 721 | |
07f6a794 MZ |
722 | mutex_lock(&ima_rules_mutex); |
723 | list_for_each_entry_safe(entry, tmp, &ima_policy_rules, list) { | |
7163a993 MZ |
724 | for (i = 0; i < MAX_LSM_RULES; i++) |
725 | kfree(entry->lsm[i].args_p); | |
726 | ||
4af4662f MZ |
727 | list_del(&entry->list); |
728 | kfree(entry); | |
729 | } | |
07f6a794 | 730 | mutex_unlock(&ima_rules_mutex); |
4af4662f | 731 | } |