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