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
10  *	- initialize default measure policy rules
11  *
12  */
13 #include <linux/init.h>
14 #include <linux/list.h>
15 #include <linux/fs.h>
16 #include <linux/security.h>
17 #include <linux/magic.h>
18 #include <linux/parser.h>
19 #include <linux/slab.h>
20 #include <linux/rculist.h>
21 #include <linux/genhd.h>
22 #include <linux/seq_file.h>
23 #include <linux/ima.h>
24 
25 #include "ima.h"
26 
27 /* flags definitions */
28 #define IMA_FUNC	0x0001
29 #define IMA_MASK	0x0002
30 #define IMA_FSMAGIC	0x0004
31 #define IMA_UID		0x0008
32 #define IMA_FOWNER	0x0010
33 #define IMA_FSUUID	0x0020
34 #define IMA_INMASK	0x0040
35 #define IMA_EUID	0x0080
36 #define IMA_PCR		0x0100
37 #define IMA_FSNAME	0x0200
38 
39 #define UNKNOWN		0
40 #define MEASURE		0x0001	/* same as IMA_MEASURE */
41 #define DONT_MEASURE	0x0002
42 #define APPRAISE	0x0004	/* same as IMA_APPRAISE */
43 #define DONT_APPRAISE	0x0008
44 #define AUDIT		0x0040
45 #define HASH		0x0100
46 #define DONT_HASH	0x0200
47 
48 #define INVALID_PCR(a) (((a) < 0) || \
49 	(a) >= (FIELD_SIZEOF(struct integrity_iint_cache, measured_pcrs) * 8))
50 
51 int ima_policy_flag;
52 static int temp_ima_appraise;
53 static int build_ima_appraise __ro_after_init;
54 
55 #define MAX_LSM_RULES 6
56 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
57 	LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
58 };
59 
60 enum policy_types { ORIGINAL_TCB = 1, DEFAULT_TCB };
61 
62 enum policy_rule_list { IMA_DEFAULT_POLICY = 1, IMA_CUSTOM_POLICY };
63 
64 struct ima_rule_entry {
65 	struct list_head list;
66 	int action;
67 	unsigned int flags;
68 	enum ima_hooks func;
69 	int mask;
70 	unsigned long fsmagic;
71 	uuid_t fsuuid;
72 	kuid_t uid;
73 	kuid_t fowner;
74 	bool (*uid_op)(kuid_t, kuid_t);    /* Handlers for operators       */
75 	bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
76 	int pcr;
77 	struct {
78 		void *rule;	/* LSM file metadata specific */
79 		void *args_p;	/* audit value */
80 		int type;	/* audit type */
81 	} lsm[MAX_LSM_RULES];
82 	char *fsname;
83 };
84 
85 /*
86  * Without LSM specific knowledge, the default policy can only be
87  * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
88  */
89 
90 /*
91  * The minimum rule set to allow for full TCB coverage.  Measures all files
92  * opened or mmap for exec and everything read by root.  Dangerous because
93  * normal users can easily run the machine out of memory simply building
94  * and running executables.
95  */
96 static struct ima_rule_entry dont_measure_rules[] __ro_after_init = {
97 	{.action = DONT_MEASURE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
98 	{.action = DONT_MEASURE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
99 	{.action = DONT_MEASURE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
100 	{.action = DONT_MEASURE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
101 	{.action = DONT_MEASURE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC},
102 	{.action = DONT_MEASURE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
103 	{.action = DONT_MEASURE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
104 	{.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
105 	{.action = DONT_MEASURE, .fsmagic = SMACK_MAGIC, .flags = IMA_FSMAGIC},
106 	{.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC,
107 	 .flags = IMA_FSMAGIC},
108 	{.action = DONT_MEASURE, .fsmagic = CGROUP2_SUPER_MAGIC,
109 	 .flags = IMA_FSMAGIC},
110 	{.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
111 	{.action = DONT_MEASURE, .fsmagic = EFIVARFS_MAGIC, .flags = IMA_FSMAGIC}
112 };
113 
114 static struct ima_rule_entry original_measurement_rules[] __ro_after_init = {
115 	{.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
116 	 .flags = IMA_FUNC | IMA_MASK},
117 	{.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
118 	 .flags = IMA_FUNC | IMA_MASK},
119 	{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
120 	 .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq,
121 	 .flags = IMA_FUNC | IMA_MASK | IMA_UID},
122 	{.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
123 	{.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
124 };
125 
126 static struct ima_rule_entry default_measurement_rules[] __ro_after_init = {
127 	{.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
128 	 .flags = IMA_FUNC | IMA_MASK},
129 	{.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
130 	 .flags = IMA_FUNC | IMA_MASK},
131 	{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
132 	 .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq,
133 	 .flags = IMA_FUNC | IMA_INMASK | IMA_EUID},
134 	{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
135 	 .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq,
136 	 .flags = IMA_FUNC | IMA_INMASK | IMA_UID},
137 	{.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
138 	{.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
139 	{.action = MEASURE, .func = POLICY_CHECK, .flags = IMA_FUNC},
140 };
141 
142 static struct ima_rule_entry default_appraise_rules[] __ro_after_init = {
143 	{.action = DONT_APPRAISE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
144 	{.action = DONT_APPRAISE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
145 	{.action = DONT_APPRAISE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
146 	{.action = DONT_APPRAISE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
147 	{.action = DONT_APPRAISE, .fsmagic = RAMFS_MAGIC, .flags = IMA_FSMAGIC},
148 	{.action = DONT_APPRAISE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC},
149 	{.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
150 	{.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
151 	{.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
152 	{.action = DONT_APPRAISE, .fsmagic = SMACK_MAGIC, .flags = IMA_FSMAGIC},
153 	{.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
154 	{.action = DONT_APPRAISE, .fsmagic = EFIVARFS_MAGIC, .flags = IMA_FSMAGIC},
155 	{.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC},
156 	{.action = DONT_APPRAISE, .fsmagic = CGROUP2_SUPER_MAGIC, .flags = IMA_FSMAGIC},
157 #ifdef CONFIG_IMA_WRITE_POLICY
158 	{.action = APPRAISE, .func = POLICY_CHECK,
159 	.flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
160 #endif
161 #ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT
162 	{.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .fowner_op = &uid_eq,
163 	 .flags = IMA_FOWNER},
164 #else
165 	/* force signature */
166 	{.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .fowner_op = &uid_eq,
167 	 .flags = IMA_FOWNER | IMA_DIGSIG_REQUIRED},
168 #endif
169 };
170 
171 static struct ima_rule_entry build_appraise_rules[] __ro_after_init = {
172 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_MODULE_SIGS
173 	{.action = APPRAISE, .func = MODULE_CHECK,
174 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
175 #endif
176 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
177 	{.action = APPRAISE, .func = FIRMWARE_CHECK,
178 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
179 #endif
180 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_KEXEC_SIGS
181 	{.action = APPRAISE, .func = KEXEC_KERNEL_CHECK,
182 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
183 #endif
184 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_POLICY_SIGS
185 	{.action = APPRAISE, .func = POLICY_CHECK,
186 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
187 #endif
188 };
189 
190 static struct ima_rule_entry secure_boot_rules[] __ro_after_init = {
191 	{.action = APPRAISE, .func = MODULE_CHECK,
192 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
193 	{.action = APPRAISE, .func = FIRMWARE_CHECK,
194 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
195 	{.action = APPRAISE, .func = KEXEC_KERNEL_CHECK,
196 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
197 	{.action = APPRAISE, .func = POLICY_CHECK,
198 	 .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
199 };
200 
201 /* An array of architecture specific rules */
202 struct ima_rule_entry *arch_policy_entry __ro_after_init;
203 
204 static LIST_HEAD(ima_default_rules);
205 static LIST_HEAD(ima_policy_rules);
206 static LIST_HEAD(ima_temp_rules);
207 static struct list_head *ima_rules;
208 
209 static int ima_policy __initdata;
210 
211 static int __init default_measure_policy_setup(char *str)
212 {
213 	if (ima_policy)
214 		return 1;
215 
216 	ima_policy = ORIGINAL_TCB;
217 	return 1;
218 }
219 __setup("ima_tcb", default_measure_policy_setup);
220 
221 static bool ima_use_appraise_tcb __initdata;
222 static bool ima_use_secure_boot __initdata;
223 static bool ima_fail_unverifiable_sigs __ro_after_init;
224 static int __init policy_setup(char *str)
225 {
226 	char *p;
227 
228 	while ((p = strsep(&str, " |\n")) != NULL) {
229 		if (*p == ' ')
230 			continue;
231 		if ((strcmp(p, "tcb") == 0) && !ima_policy)
232 			ima_policy = DEFAULT_TCB;
233 		else if (strcmp(p, "appraise_tcb") == 0)
234 			ima_use_appraise_tcb = true;
235 		else if (strcmp(p, "secure_boot") == 0)
236 			ima_use_secure_boot = true;
237 		else if (strcmp(p, "fail_securely") == 0)
238 			ima_fail_unverifiable_sigs = true;
239 	}
240 
241 	return 1;
242 }
243 __setup("ima_policy=", policy_setup);
244 
245 static int __init default_appraise_policy_setup(char *str)
246 {
247 	ima_use_appraise_tcb = true;
248 	return 1;
249 }
250 __setup("ima_appraise_tcb", default_appraise_policy_setup);
251 
252 /*
253  * The LSM policy can be reloaded, leaving the IMA LSM based rules referring
254  * to the old, stale LSM policy.  Update the IMA LSM based rules to reflect
255  * the reloaded LSM policy.  We assume the rules still exist; and BUG_ON() if
256  * they don't.
257  */
258 static void ima_lsm_update_rules(void)
259 {
260 	struct ima_rule_entry *entry;
261 	int result;
262 	int i;
263 
264 	list_for_each_entry(entry, &ima_policy_rules, list) {
265 		for (i = 0; i < MAX_LSM_RULES; i++) {
266 			if (!entry->lsm[i].rule)
267 				continue;
268 			result = security_filter_rule_init(entry->lsm[i].type,
269 							   Audit_equal,
270 							   entry->lsm[i].args_p,
271 							   &entry->lsm[i].rule);
272 			BUG_ON(!entry->lsm[i].rule);
273 		}
274 	}
275 }
276 
277 /**
278  * ima_match_rules - determine whether an inode matches the measure rule.
279  * @rule: a pointer to a rule
280  * @inode: a pointer to an inode
281  * @cred: a pointer to a credentials structure for user validation
282  * @secid: the secid of the task to be validated
283  * @func: LIM hook identifier
284  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
285  *
286  * Returns true on rule match, false on failure.
287  */
288 static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
289 			    const struct cred *cred, u32 secid,
290 			    enum ima_hooks func, int mask)
291 {
292 	int i;
293 
294 	if ((rule->flags & IMA_FUNC) &&
295 	    (rule->func != func && func != POST_SETATTR))
296 		return false;
297 	if ((rule->flags & IMA_MASK) &&
298 	    (rule->mask != mask && func != POST_SETATTR))
299 		return false;
300 	if ((rule->flags & IMA_INMASK) &&
301 	    (!(rule->mask & mask) && func != POST_SETATTR))
302 		return false;
303 	if ((rule->flags & IMA_FSMAGIC)
304 	    && rule->fsmagic != inode->i_sb->s_magic)
305 		return false;
306 	if ((rule->flags & IMA_FSNAME)
307 	    && strcmp(rule->fsname, inode->i_sb->s_type->name))
308 		return false;
309 	if ((rule->flags & IMA_FSUUID) &&
310 	    !uuid_equal(&rule->fsuuid, &inode->i_sb->s_uuid))
311 		return false;
312 	if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
313 		return false;
314 	if (rule->flags & IMA_EUID) {
315 		if (has_capability_noaudit(current, CAP_SETUID)) {
316 			if (!rule->uid_op(cred->euid, rule->uid)
317 			    && !rule->uid_op(cred->suid, rule->uid)
318 			    && !rule->uid_op(cred->uid, rule->uid))
319 				return false;
320 		} else if (!rule->uid_op(cred->euid, rule->uid))
321 			return false;
322 	}
323 
324 	if ((rule->flags & IMA_FOWNER) &&
325 	    !rule->fowner_op(inode->i_uid, rule->fowner))
326 		return false;
327 	for (i = 0; i < MAX_LSM_RULES; i++) {
328 		int rc = 0;
329 		u32 osid;
330 		int retried = 0;
331 
332 		if (!rule->lsm[i].rule)
333 			continue;
334 retry:
335 		switch (i) {
336 		case LSM_OBJ_USER:
337 		case LSM_OBJ_ROLE:
338 		case LSM_OBJ_TYPE:
339 			security_inode_getsecid(inode, &osid);
340 			rc = security_filter_rule_match(osid,
341 							rule->lsm[i].type,
342 							Audit_equal,
343 							rule->lsm[i].rule,
344 							NULL);
345 			break;
346 		case LSM_SUBJ_USER:
347 		case LSM_SUBJ_ROLE:
348 		case LSM_SUBJ_TYPE:
349 			rc = security_filter_rule_match(secid,
350 							rule->lsm[i].type,
351 							Audit_equal,
352 							rule->lsm[i].rule,
353 							NULL);
354 		default:
355 			break;
356 		}
357 		if ((rc < 0) && (!retried)) {
358 			retried = 1;
359 			ima_lsm_update_rules();
360 			goto retry;
361 		}
362 		if (!rc)
363 			return false;
364 	}
365 	return true;
366 }
367 
368 /*
369  * In addition to knowing that we need to appraise the file in general,
370  * we need to differentiate between calling hooks, for hook specific rules.
371  */
372 static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
373 {
374 	if (!(rule->flags & IMA_FUNC))
375 		return IMA_FILE_APPRAISE;
376 
377 	switch (func) {
378 	case MMAP_CHECK:
379 		return IMA_MMAP_APPRAISE;
380 	case BPRM_CHECK:
381 		return IMA_BPRM_APPRAISE;
382 	case CREDS_CHECK:
383 		return IMA_CREDS_APPRAISE;
384 	case FILE_CHECK:
385 	case POST_SETATTR:
386 		return IMA_FILE_APPRAISE;
387 	case MODULE_CHECK ... MAX_CHECK - 1:
388 	default:
389 		return IMA_READ_APPRAISE;
390 	}
391 }
392 
393 /**
394  * ima_match_policy - decision based on LSM and other conditions
395  * @inode: pointer to an inode for which the policy decision is being made
396  * @cred: pointer to a credentials structure for which the policy decision is
397  *        being made
398  * @secid: LSM secid of the task to be validated
399  * @func: IMA hook identifier
400  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
401  * @pcr: set the pcr to extend
402  *
403  * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
404  * conditions.
405  *
406  * Since the IMA policy may be updated multiple times we need to lock the
407  * list when walking it.  Reads are many orders of magnitude more numerous
408  * than writes so ima_match_policy() is classical RCU candidate.
409  */
410 int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
411 		     enum ima_hooks func, int mask, int flags, int *pcr)
412 {
413 	struct ima_rule_entry *entry;
414 	int action = 0, actmask = flags | (flags << 1);
415 
416 	rcu_read_lock();
417 	list_for_each_entry_rcu(entry, ima_rules, list) {
418 
419 		if (!(entry->action & actmask))
420 			continue;
421 
422 		if (!ima_match_rules(entry, inode, cred, secid, func, mask))
423 			continue;
424 
425 		action |= entry->flags & IMA_ACTION_FLAGS;
426 
427 		action |= entry->action & IMA_DO_MASK;
428 		if (entry->action & IMA_APPRAISE) {
429 			action |= get_subaction(entry, func);
430 			action &= ~IMA_HASH;
431 			if (ima_fail_unverifiable_sigs)
432 				action |= IMA_FAIL_UNVERIFIABLE_SIGS;
433 		}
434 
435 		if (entry->action & IMA_DO_MASK)
436 			actmask &= ~(entry->action | entry->action << 1);
437 		else
438 			actmask &= ~(entry->action | entry->action >> 1);
439 
440 		if ((pcr) && (entry->flags & IMA_PCR))
441 			*pcr = entry->pcr;
442 
443 		if (!actmask)
444 			break;
445 	}
446 	rcu_read_unlock();
447 
448 	return action;
449 }
450 
451 /*
452  * Initialize the ima_policy_flag variable based on the currently
453  * loaded policy.  Based on this flag, the decision to short circuit
454  * out of a function or not call the function in the first place
455  * can be made earlier.
456  */
457 void ima_update_policy_flag(void)
458 {
459 	struct ima_rule_entry *entry;
460 
461 	list_for_each_entry(entry, ima_rules, list) {
462 		if (entry->action & IMA_DO_MASK)
463 			ima_policy_flag |= entry->action;
464 	}
465 
466 	ima_appraise |= (build_ima_appraise | temp_ima_appraise);
467 	if (!ima_appraise)
468 		ima_policy_flag &= ~IMA_APPRAISE;
469 }
470 
471 static int ima_appraise_flag(enum ima_hooks func)
472 {
473 	if (func == MODULE_CHECK)
474 		return IMA_APPRAISE_MODULES;
475 	else if (func == FIRMWARE_CHECK)
476 		return IMA_APPRAISE_FIRMWARE;
477 	else if (func == POLICY_CHECK)
478 		return IMA_APPRAISE_POLICY;
479 	else if (func == KEXEC_KERNEL_CHECK)
480 		return IMA_APPRAISE_KEXEC;
481 	return 0;
482 }
483 
484 static void add_rules(struct ima_rule_entry *entries, int count,
485 		      enum policy_rule_list policy_rule)
486 {
487 	int i = 0;
488 
489 	for (i = 0; i < count; i++) {
490 		struct ima_rule_entry *entry;
491 
492 		if (policy_rule & IMA_DEFAULT_POLICY)
493 			list_add_tail(&entries[i].list, &ima_default_rules);
494 
495 		if (policy_rule & IMA_CUSTOM_POLICY) {
496 			entry = kmemdup(&entries[i], sizeof(*entry),
497 					GFP_KERNEL);
498 			if (!entry)
499 				continue;
500 
501 			list_add_tail(&entry->list, &ima_policy_rules);
502 		}
503 		if (entries[i].action == APPRAISE)
504 			temp_ima_appraise |= ima_appraise_flag(entries[i].func);
505 		if (entries[i].func == POLICY_CHECK)
506 			temp_ima_appraise |= IMA_APPRAISE_POLICY;
507 	}
508 }
509 
510 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry);
511 
512 static int __init ima_init_arch_policy(void)
513 {
514 	const char * const *arch_rules;
515 	const char * const *rules;
516 	int arch_entries = 0;
517 	int i = 0;
518 
519 	arch_rules = arch_get_ima_policy();
520 	if (!arch_rules)
521 		return arch_entries;
522 
523 	/* Get number of rules */
524 	for (rules = arch_rules; *rules != NULL; rules++)
525 		arch_entries++;
526 
527 	arch_policy_entry = kcalloc(arch_entries + 1,
528 				    sizeof(*arch_policy_entry), GFP_KERNEL);
529 	if (!arch_policy_entry)
530 		return 0;
531 
532 	/* Convert each policy string rules to struct ima_rule_entry format */
533 	for (rules = arch_rules, i = 0; *rules != NULL; rules++) {
534 		char rule[255];
535 		int result;
536 
537 		result = strlcpy(rule, *rules, sizeof(rule));
538 
539 		INIT_LIST_HEAD(&arch_policy_entry[i].list);
540 		result = ima_parse_rule(rule, &arch_policy_entry[i]);
541 		if (result) {
542 			pr_warn("Skipping unknown architecture policy rule: %s\n",
543 				rule);
544 			memset(&arch_policy_entry[i], 0,
545 			       sizeof(*arch_policy_entry));
546 			continue;
547 		}
548 		i++;
549 	}
550 	return i;
551 }
552 
553 /**
554  * ima_init_policy - initialize the default measure rules.
555  *
556  * ima_rules points to either the ima_default_rules or the
557  * the new ima_policy_rules.
558  */
559 void __init ima_init_policy(void)
560 {
561 	int build_appraise_entries, arch_entries;
562 
563 	/* if !ima_policy, we load NO default rules */
564 	if (ima_policy)
565 		add_rules(dont_measure_rules, ARRAY_SIZE(dont_measure_rules),
566 			  IMA_DEFAULT_POLICY);
567 
568 	switch (ima_policy) {
569 	case ORIGINAL_TCB:
570 		add_rules(original_measurement_rules,
571 			  ARRAY_SIZE(original_measurement_rules),
572 			  IMA_DEFAULT_POLICY);
573 		break;
574 	case DEFAULT_TCB:
575 		add_rules(default_measurement_rules,
576 			  ARRAY_SIZE(default_measurement_rules),
577 			  IMA_DEFAULT_POLICY);
578 	default:
579 		break;
580 	}
581 
582 	/*
583 	 * Based on runtime secure boot flags, insert arch specific measurement
584 	 * and appraise rules requiring file signatures for both the initial
585 	 * and custom policies, prior to other appraise rules.
586 	 * (Highest priority)
587 	 */
588 	arch_entries = ima_init_arch_policy();
589 	if (!arch_entries)
590 		pr_info("No architecture policies found\n");
591 	else
592 		add_rules(arch_policy_entry, arch_entries,
593 			  IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY);
594 
595 	/*
596 	 * Insert the builtin "secure_boot" policy rules requiring file
597 	 * signatures, prior to other appraise rules.
598 	 */
599 	if (ima_use_secure_boot)
600 		add_rules(secure_boot_rules, ARRAY_SIZE(secure_boot_rules),
601 			  IMA_DEFAULT_POLICY);
602 
603 	/*
604 	 * Insert the build time appraise rules requiring file signatures
605 	 * for both the initial and custom policies, prior to other appraise
606 	 * rules. As the secure boot rules includes all of the build time
607 	 * rules, include either one or the other set of rules, but not both.
608 	 */
609 	build_appraise_entries = ARRAY_SIZE(build_appraise_rules);
610 	if (build_appraise_entries) {
611 		if (ima_use_secure_boot)
612 			add_rules(build_appraise_rules, build_appraise_entries,
613 				  IMA_CUSTOM_POLICY);
614 		else
615 			add_rules(build_appraise_rules, build_appraise_entries,
616 				  IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY);
617 	}
618 
619 	if (ima_use_appraise_tcb)
620 		add_rules(default_appraise_rules,
621 			  ARRAY_SIZE(default_appraise_rules),
622 			  IMA_DEFAULT_POLICY);
623 
624 	ima_rules = &ima_default_rules;
625 	ima_update_policy_flag();
626 }
627 
628 /* Make sure we have a valid policy, at least containing some rules. */
629 int ima_check_policy(void)
630 {
631 	if (list_empty(&ima_temp_rules))
632 		return -EINVAL;
633 	return 0;
634 }
635 
636 /**
637  * ima_update_policy - update default_rules with new measure rules
638  *
639  * Called on file .release to update the default rules with a complete new
640  * policy.  What we do here is to splice ima_policy_rules and ima_temp_rules so
641  * they make a queue.  The policy may be updated multiple times and this is the
642  * RCU updater.
643  *
644  * Policy rules are never deleted so ima_policy_flag gets zeroed only once when
645  * we switch from the default policy to user defined.
646  */
647 void ima_update_policy(void)
648 {
649 	struct list_head *policy = &ima_policy_rules;
650 
651 	list_splice_tail_init_rcu(&ima_temp_rules, policy, synchronize_rcu);
652 
653 	if (ima_rules != policy) {
654 		ima_policy_flag = 0;
655 		ima_rules = policy;
656 
657 		/*
658 		 * IMA architecture specific policy rules are specified
659 		 * as strings and converted to an array of ima_entry_rules
660 		 * on boot.  After loading a custom policy, free the
661 		 * architecture specific rules stored as an array.
662 		 */
663 		kfree(arch_policy_entry);
664 	}
665 	ima_update_policy_flag();
666 }
667 
668 /* Keep the enumeration in sync with the policy_tokens! */
669 enum {
670 	Opt_measure, Opt_dont_measure,
671 	Opt_appraise, Opt_dont_appraise,
672 	Opt_audit, Opt_hash, Opt_dont_hash,
673 	Opt_obj_user, Opt_obj_role, Opt_obj_type,
674 	Opt_subj_user, Opt_subj_role, Opt_subj_type,
675 	Opt_func, Opt_mask, Opt_fsmagic, Opt_fsname,
676 	Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq,
677 	Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt,
678 	Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
679 	Opt_appraise_type, Opt_permit_directio,
680 	Opt_pcr, Opt_err
681 };
682 
683 static const match_table_t policy_tokens = {
684 	{Opt_measure, "measure"},
685 	{Opt_dont_measure, "dont_measure"},
686 	{Opt_appraise, "appraise"},
687 	{Opt_dont_appraise, "dont_appraise"},
688 	{Opt_audit, "audit"},
689 	{Opt_hash, "hash"},
690 	{Opt_dont_hash, "dont_hash"},
691 	{Opt_obj_user, "obj_user=%s"},
692 	{Opt_obj_role, "obj_role=%s"},
693 	{Opt_obj_type, "obj_type=%s"},
694 	{Opt_subj_user, "subj_user=%s"},
695 	{Opt_subj_role, "subj_role=%s"},
696 	{Opt_subj_type, "subj_type=%s"},
697 	{Opt_func, "func=%s"},
698 	{Opt_mask, "mask=%s"},
699 	{Opt_fsmagic, "fsmagic=%s"},
700 	{Opt_fsname, "fsname=%s"},
701 	{Opt_fsuuid, "fsuuid=%s"},
702 	{Opt_uid_eq, "uid=%s"},
703 	{Opt_euid_eq, "euid=%s"},
704 	{Opt_fowner_eq, "fowner=%s"},
705 	{Opt_uid_gt, "uid>%s"},
706 	{Opt_euid_gt, "euid>%s"},
707 	{Opt_fowner_gt, "fowner>%s"},
708 	{Opt_uid_lt, "uid<%s"},
709 	{Opt_euid_lt, "euid<%s"},
710 	{Opt_fowner_lt, "fowner<%s"},
711 	{Opt_appraise_type, "appraise_type=%s"},
712 	{Opt_permit_directio, "permit_directio"},
713 	{Opt_pcr, "pcr=%s"},
714 	{Opt_err, NULL}
715 };
716 
717 static int ima_lsm_rule_init(struct ima_rule_entry *entry,
718 			     substring_t *args, int lsm_rule, int audit_type)
719 {
720 	int result;
721 
722 	if (entry->lsm[lsm_rule].rule)
723 		return -EINVAL;
724 
725 	entry->lsm[lsm_rule].args_p = match_strdup(args);
726 	if (!entry->lsm[lsm_rule].args_p)
727 		return -ENOMEM;
728 
729 	entry->lsm[lsm_rule].type = audit_type;
730 	result = security_filter_rule_init(entry->lsm[lsm_rule].type,
731 					   Audit_equal,
732 					   entry->lsm[lsm_rule].args_p,
733 					   &entry->lsm[lsm_rule].rule);
734 	if (!entry->lsm[lsm_rule].rule) {
735 		kfree(entry->lsm[lsm_rule].args_p);
736 		return -EINVAL;
737 	}
738 
739 	return result;
740 }
741 
742 static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
743 			      bool (*rule_operator)(kuid_t, kuid_t))
744 {
745 	if (!ab)
746 		return;
747 
748 	if (rule_operator == &uid_gt)
749 		audit_log_format(ab, "%s>", key);
750 	else if (rule_operator == &uid_lt)
751 		audit_log_format(ab, "%s<", key);
752 	else
753 		audit_log_format(ab, "%s=", key);
754 	audit_log_format(ab, "%s ", value);
755 }
756 static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
757 {
758 	ima_log_string_op(ab, key, value, NULL);
759 }
760 
761 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
762 {
763 	struct audit_buffer *ab;
764 	char *from;
765 	char *p;
766 	bool uid_token;
767 	int result = 0;
768 
769 	ab = integrity_audit_log_start(audit_context(), GFP_KERNEL,
770 				       AUDIT_INTEGRITY_POLICY_RULE);
771 
772 	entry->uid = INVALID_UID;
773 	entry->fowner = INVALID_UID;
774 	entry->uid_op = &uid_eq;
775 	entry->fowner_op = &uid_eq;
776 	entry->action = UNKNOWN;
777 	while ((p = strsep(&rule, " \t")) != NULL) {
778 		substring_t args[MAX_OPT_ARGS];
779 		int token;
780 		unsigned long lnum;
781 
782 		if (result < 0)
783 			break;
784 		if ((*p == '\0') || (*p == ' ') || (*p == '\t'))
785 			continue;
786 		token = match_token(p, policy_tokens, args);
787 		switch (token) {
788 		case Opt_measure:
789 			ima_log_string(ab, "action", "measure");
790 
791 			if (entry->action != UNKNOWN)
792 				result = -EINVAL;
793 
794 			entry->action = MEASURE;
795 			break;
796 		case Opt_dont_measure:
797 			ima_log_string(ab, "action", "dont_measure");
798 
799 			if (entry->action != UNKNOWN)
800 				result = -EINVAL;
801 
802 			entry->action = DONT_MEASURE;
803 			break;
804 		case Opt_appraise:
805 			ima_log_string(ab, "action", "appraise");
806 
807 			if (entry->action != UNKNOWN)
808 				result = -EINVAL;
809 
810 			entry->action = APPRAISE;
811 			break;
812 		case Opt_dont_appraise:
813 			ima_log_string(ab, "action", "dont_appraise");
814 
815 			if (entry->action != UNKNOWN)
816 				result = -EINVAL;
817 
818 			entry->action = DONT_APPRAISE;
819 			break;
820 		case Opt_audit:
821 			ima_log_string(ab, "action", "audit");
822 
823 			if (entry->action != UNKNOWN)
824 				result = -EINVAL;
825 
826 			entry->action = AUDIT;
827 			break;
828 		case Opt_hash:
829 			ima_log_string(ab, "action", "hash");
830 
831 			if (entry->action != UNKNOWN)
832 				result = -EINVAL;
833 
834 			entry->action = HASH;
835 			break;
836 		case Opt_dont_hash:
837 			ima_log_string(ab, "action", "dont_hash");
838 
839 			if (entry->action != UNKNOWN)
840 				result = -EINVAL;
841 
842 			entry->action = DONT_HASH;
843 			break;
844 		case Opt_func:
845 			ima_log_string(ab, "func", args[0].from);
846 
847 			if (entry->func)
848 				result = -EINVAL;
849 
850 			if (strcmp(args[0].from, "FILE_CHECK") == 0)
851 				entry->func = FILE_CHECK;
852 			/* PATH_CHECK is for backwards compat */
853 			else if (strcmp(args[0].from, "PATH_CHECK") == 0)
854 				entry->func = FILE_CHECK;
855 			else if (strcmp(args[0].from, "MODULE_CHECK") == 0)
856 				entry->func = MODULE_CHECK;
857 			else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0)
858 				entry->func = FIRMWARE_CHECK;
859 			else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
860 				|| (strcmp(args[0].from, "MMAP_CHECK") == 0))
861 				entry->func = MMAP_CHECK;
862 			else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
863 				entry->func = BPRM_CHECK;
864 			else if (strcmp(args[0].from, "CREDS_CHECK") == 0)
865 				entry->func = CREDS_CHECK;
866 			else if (strcmp(args[0].from, "KEXEC_KERNEL_CHECK") ==
867 				 0)
868 				entry->func = KEXEC_KERNEL_CHECK;
869 			else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK")
870 				 == 0)
871 				entry->func = KEXEC_INITRAMFS_CHECK;
872 			else if (strcmp(args[0].from, "POLICY_CHECK") == 0)
873 				entry->func = POLICY_CHECK;
874 			else
875 				result = -EINVAL;
876 			if (!result)
877 				entry->flags |= IMA_FUNC;
878 			break;
879 		case Opt_mask:
880 			ima_log_string(ab, "mask", args[0].from);
881 
882 			if (entry->mask)
883 				result = -EINVAL;
884 
885 			from = args[0].from;
886 			if (*from == '^')
887 				from++;
888 
889 			if ((strcmp(from, "MAY_EXEC")) == 0)
890 				entry->mask = MAY_EXEC;
891 			else if (strcmp(from, "MAY_WRITE") == 0)
892 				entry->mask = MAY_WRITE;
893 			else if (strcmp(from, "MAY_READ") == 0)
894 				entry->mask = MAY_READ;
895 			else if (strcmp(from, "MAY_APPEND") == 0)
896 				entry->mask = MAY_APPEND;
897 			else
898 				result = -EINVAL;
899 			if (!result)
900 				entry->flags |= (*args[0].from == '^')
901 				     ? IMA_INMASK : IMA_MASK;
902 			break;
903 		case Opt_fsmagic:
904 			ima_log_string(ab, "fsmagic", args[0].from);
905 
906 			if (entry->fsmagic) {
907 				result = -EINVAL;
908 				break;
909 			}
910 
911 			result = kstrtoul(args[0].from, 16, &entry->fsmagic);
912 			if (!result)
913 				entry->flags |= IMA_FSMAGIC;
914 			break;
915 		case Opt_fsname:
916 			ima_log_string(ab, "fsname", args[0].from);
917 
918 			entry->fsname = kstrdup(args[0].from, GFP_KERNEL);
919 			if (!entry->fsname) {
920 				result = -ENOMEM;
921 				break;
922 			}
923 			result = 0;
924 			entry->flags |= IMA_FSNAME;
925 			break;
926 		case Opt_fsuuid:
927 			ima_log_string(ab, "fsuuid", args[0].from);
928 
929 			if (!uuid_is_null(&entry->fsuuid)) {
930 				result = -EINVAL;
931 				break;
932 			}
933 
934 			result = uuid_parse(args[0].from, &entry->fsuuid);
935 			if (!result)
936 				entry->flags |= IMA_FSUUID;
937 			break;
938 		case Opt_uid_gt:
939 		case Opt_euid_gt:
940 			entry->uid_op = &uid_gt;
941 		case Opt_uid_lt:
942 		case Opt_euid_lt:
943 			if ((token == Opt_uid_lt) || (token == Opt_euid_lt))
944 				entry->uid_op = &uid_lt;
945 		case Opt_uid_eq:
946 		case Opt_euid_eq:
947 			uid_token = (token == Opt_uid_eq) ||
948 				    (token == Opt_uid_gt) ||
949 				    (token == Opt_uid_lt);
950 
951 			ima_log_string_op(ab, uid_token ? "uid" : "euid",
952 					  args[0].from, entry->uid_op);
953 
954 			if (uid_valid(entry->uid)) {
955 				result = -EINVAL;
956 				break;
957 			}
958 
959 			result = kstrtoul(args[0].from, 10, &lnum);
960 			if (!result) {
961 				entry->uid = make_kuid(current_user_ns(),
962 						       (uid_t) lnum);
963 				if (!uid_valid(entry->uid) ||
964 				    (uid_t)lnum != lnum)
965 					result = -EINVAL;
966 				else
967 					entry->flags |= uid_token
968 					    ? IMA_UID : IMA_EUID;
969 			}
970 			break;
971 		case Opt_fowner_gt:
972 			entry->fowner_op = &uid_gt;
973 		case Opt_fowner_lt:
974 			if (token == Opt_fowner_lt)
975 				entry->fowner_op = &uid_lt;
976 		case Opt_fowner_eq:
977 			ima_log_string_op(ab, "fowner", args[0].from,
978 					  entry->fowner_op);
979 
980 			if (uid_valid(entry->fowner)) {
981 				result = -EINVAL;
982 				break;
983 			}
984 
985 			result = kstrtoul(args[0].from, 10, &lnum);
986 			if (!result) {
987 				entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
988 				if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
989 					result = -EINVAL;
990 				else
991 					entry->flags |= IMA_FOWNER;
992 			}
993 			break;
994 		case Opt_obj_user:
995 			ima_log_string(ab, "obj_user", args[0].from);
996 			result = ima_lsm_rule_init(entry, args,
997 						   LSM_OBJ_USER,
998 						   AUDIT_OBJ_USER);
999 			break;
1000 		case Opt_obj_role:
1001 			ima_log_string(ab, "obj_role", args[0].from);
1002 			result = ima_lsm_rule_init(entry, args,
1003 						   LSM_OBJ_ROLE,
1004 						   AUDIT_OBJ_ROLE);
1005 			break;
1006 		case Opt_obj_type:
1007 			ima_log_string(ab, "obj_type", args[0].from);
1008 			result = ima_lsm_rule_init(entry, args,
1009 						   LSM_OBJ_TYPE,
1010 						   AUDIT_OBJ_TYPE);
1011 			break;
1012 		case Opt_subj_user:
1013 			ima_log_string(ab, "subj_user", args[0].from);
1014 			result = ima_lsm_rule_init(entry, args,
1015 						   LSM_SUBJ_USER,
1016 						   AUDIT_SUBJ_USER);
1017 			break;
1018 		case Opt_subj_role:
1019 			ima_log_string(ab, "subj_role", args[0].from);
1020 			result = ima_lsm_rule_init(entry, args,
1021 						   LSM_SUBJ_ROLE,
1022 						   AUDIT_SUBJ_ROLE);
1023 			break;
1024 		case Opt_subj_type:
1025 			ima_log_string(ab, "subj_type", args[0].from);
1026 			result = ima_lsm_rule_init(entry, args,
1027 						   LSM_SUBJ_TYPE,
1028 						   AUDIT_SUBJ_TYPE);
1029 			break;
1030 		case Opt_appraise_type:
1031 			if (entry->action != APPRAISE) {
1032 				result = -EINVAL;
1033 				break;
1034 			}
1035 
1036 			ima_log_string(ab, "appraise_type", args[0].from);
1037 			if ((strcmp(args[0].from, "imasig")) == 0)
1038 				entry->flags |= IMA_DIGSIG_REQUIRED;
1039 			else
1040 				result = -EINVAL;
1041 			break;
1042 		case Opt_permit_directio:
1043 			entry->flags |= IMA_PERMIT_DIRECTIO;
1044 			break;
1045 		case Opt_pcr:
1046 			if (entry->action != MEASURE) {
1047 				result = -EINVAL;
1048 				break;
1049 			}
1050 			ima_log_string(ab, "pcr", args[0].from);
1051 
1052 			result = kstrtoint(args[0].from, 10, &entry->pcr);
1053 			if (result || INVALID_PCR(entry->pcr))
1054 				result = -EINVAL;
1055 			else
1056 				entry->flags |= IMA_PCR;
1057 
1058 			break;
1059 		case Opt_err:
1060 			ima_log_string(ab, "UNKNOWN", p);
1061 			result = -EINVAL;
1062 			break;
1063 		}
1064 	}
1065 	if (!result && (entry->action == UNKNOWN))
1066 		result = -EINVAL;
1067 	else if (entry->action == APPRAISE)
1068 		temp_ima_appraise |= ima_appraise_flag(entry->func);
1069 
1070 	audit_log_format(ab, "res=%d", !result);
1071 	audit_log_end(ab);
1072 	return result;
1073 }
1074 
1075 /**
1076  * ima_parse_add_rule - add a rule to ima_policy_rules
1077  * @rule - ima measurement policy rule
1078  *
1079  * Avoid locking by allowing just one writer at a time in ima_write_policy()
1080  * Returns the length of the rule parsed, an error code on failure
1081  */
1082 ssize_t ima_parse_add_rule(char *rule)
1083 {
1084 	static const char op[] = "update_policy";
1085 	char *p;
1086 	struct ima_rule_entry *entry;
1087 	ssize_t result, len;
1088 	int audit_info = 0;
1089 
1090 	p = strsep(&rule, "\n");
1091 	len = strlen(p) + 1;
1092 	p += strspn(p, " \t");
1093 
1094 	if (*p == '#' || *p == '\0')
1095 		return len;
1096 
1097 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1098 	if (!entry) {
1099 		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
1100 				    NULL, op, "-ENOMEM", -ENOMEM, audit_info);
1101 		return -ENOMEM;
1102 	}
1103 
1104 	INIT_LIST_HEAD(&entry->list);
1105 
1106 	result = ima_parse_rule(p, entry);
1107 	if (result) {
1108 		kfree(entry);
1109 		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
1110 				    NULL, op, "invalid-policy", result,
1111 				    audit_info);
1112 		return result;
1113 	}
1114 
1115 	list_add_tail(&entry->list, &ima_temp_rules);
1116 
1117 	return len;
1118 }
1119 
1120 /**
1121  * ima_delete_rules() called to cleanup invalid in-flight policy.
1122  * We don't need locking as we operate on the temp list, which is
1123  * different from the active one.  There is also only one user of
1124  * ima_delete_rules() at a time.
1125  */
1126 void ima_delete_rules(void)
1127 {
1128 	struct ima_rule_entry *entry, *tmp;
1129 	int i;
1130 
1131 	temp_ima_appraise = 0;
1132 	list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) {
1133 		for (i = 0; i < MAX_LSM_RULES; i++)
1134 			kfree(entry->lsm[i].args_p);
1135 
1136 		list_del(&entry->list);
1137 		kfree(entry);
1138 	}
1139 }
1140 
1141 #ifdef	CONFIG_IMA_READ_POLICY
1142 enum {
1143 	mask_exec = 0, mask_write, mask_read, mask_append
1144 };
1145 
1146 static const char *const mask_tokens[] = {
1147 	"MAY_EXEC",
1148 	"MAY_WRITE",
1149 	"MAY_READ",
1150 	"MAY_APPEND"
1151 };
1152 
1153 #define __ima_hook_stringify(str)	(#str),
1154 
1155 static const char *const func_tokens[] = {
1156 	__ima_hooks(__ima_hook_stringify)
1157 };
1158 
1159 void *ima_policy_start(struct seq_file *m, loff_t *pos)
1160 {
1161 	loff_t l = *pos;
1162 	struct ima_rule_entry *entry;
1163 
1164 	rcu_read_lock();
1165 	list_for_each_entry_rcu(entry, ima_rules, list) {
1166 		if (!l--) {
1167 			rcu_read_unlock();
1168 			return entry;
1169 		}
1170 	}
1171 	rcu_read_unlock();
1172 	return NULL;
1173 }
1174 
1175 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos)
1176 {
1177 	struct ima_rule_entry *entry = v;
1178 
1179 	rcu_read_lock();
1180 	entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list);
1181 	rcu_read_unlock();
1182 	(*pos)++;
1183 
1184 	return (&entry->list == ima_rules) ? NULL : entry;
1185 }
1186 
1187 void ima_policy_stop(struct seq_file *m, void *v)
1188 {
1189 }
1190 
1191 #define pt(token)	policy_tokens[token].pattern
1192 #define mt(token)	mask_tokens[token]
1193 
1194 /*
1195  * policy_func_show - display the ima_hooks policy rule
1196  */
1197 static void policy_func_show(struct seq_file *m, enum ima_hooks func)
1198 {
1199 	if (func > 0 && func < MAX_CHECK)
1200 		seq_printf(m, "func=%s ", func_tokens[func]);
1201 	else
1202 		seq_printf(m, "func=%d ", func);
1203 }
1204 
1205 int ima_policy_show(struct seq_file *m, void *v)
1206 {
1207 	struct ima_rule_entry *entry = v;
1208 	int i;
1209 	char tbuf[64] = {0,};
1210 
1211 	rcu_read_lock();
1212 
1213 	if (entry->action & MEASURE)
1214 		seq_puts(m, pt(Opt_measure));
1215 	if (entry->action & DONT_MEASURE)
1216 		seq_puts(m, pt(Opt_dont_measure));
1217 	if (entry->action & APPRAISE)
1218 		seq_puts(m, pt(Opt_appraise));
1219 	if (entry->action & DONT_APPRAISE)
1220 		seq_puts(m, pt(Opt_dont_appraise));
1221 	if (entry->action & AUDIT)
1222 		seq_puts(m, pt(Opt_audit));
1223 	if (entry->action & HASH)
1224 		seq_puts(m, pt(Opt_hash));
1225 	if (entry->action & DONT_HASH)
1226 		seq_puts(m, pt(Opt_dont_hash));
1227 
1228 	seq_puts(m, " ");
1229 
1230 	if (entry->flags & IMA_FUNC)
1231 		policy_func_show(m, entry->func);
1232 
1233 	if (entry->flags & IMA_MASK) {
1234 		if (entry->mask & MAY_EXEC)
1235 			seq_printf(m, pt(Opt_mask), mt(mask_exec));
1236 		if (entry->mask & MAY_WRITE)
1237 			seq_printf(m, pt(Opt_mask), mt(mask_write));
1238 		if (entry->mask & MAY_READ)
1239 			seq_printf(m, pt(Opt_mask), mt(mask_read));
1240 		if (entry->mask & MAY_APPEND)
1241 			seq_printf(m, pt(Opt_mask), mt(mask_append));
1242 		seq_puts(m, " ");
1243 	}
1244 
1245 	if (entry->flags & IMA_FSMAGIC) {
1246 		snprintf(tbuf, sizeof(tbuf), "0x%lx", entry->fsmagic);
1247 		seq_printf(m, pt(Opt_fsmagic), tbuf);
1248 		seq_puts(m, " ");
1249 	}
1250 
1251 	if (entry->flags & IMA_FSNAME) {
1252 		snprintf(tbuf, sizeof(tbuf), "%s", entry->fsname);
1253 		seq_printf(m, pt(Opt_fsname), tbuf);
1254 		seq_puts(m, " ");
1255 	}
1256 
1257 	if (entry->flags & IMA_PCR) {
1258 		snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
1259 		seq_printf(m, pt(Opt_pcr), tbuf);
1260 		seq_puts(m, " ");
1261 	}
1262 
1263 	if (entry->flags & IMA_FSUUID) {
1264 		seq_printf(m, "fsuuid=%pU", &entry->fsuuid);
1265 		seq_puts(m, " ");
1266 	}
1267 
1268 	if (entry->flags & IMA_UID) {
1269 		snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
1270 		if (entry->uid_op == &uid_gt)
1271 			seq_printf(m, pt(Opt_uid_gt), tbuf);
1272 		else if (entry->uid_op == &uid_lt)
1273 			seq_printf(m, pt(Opt_uid_lt), tbuf);
1274 		else
1275 			seq_printf(m, pt(Opt_uid_eq), tbuf);
1276 		seq_puts(m, " ");
1277 	}
1278 
1279 	if (entry->flags & IMA_EUID) {
1280 		snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
1281 		if (entry->uid_op == &uid_gt)
1282 			seq_printf(m, pt(Opt_euid_gt), tbuf);
1283 		else if (entry->uid_op == &uid_lt)
1284 			seq_printf(m, pt(Opt_euid_lt), tbuf);
1285 		else
1286 			seq_printf(m, pt(Opt_euid_eq), tbuf);
1287 		seq_puts(m, " ");
1288 	}
1289 
1290 	if (entry->flags & IMA_FOWNER) {
1291 		snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner));
1292 		if (entry->fowner_op == &uid_gt)
1293 			seq_printf(m, pt(Opt_fowner_gt), tbuf);
1294 		else if (entry->fowner_op == &uid_lt)
1295 			seq_printf(m, pt(Opt_fowner_lt), tbuf);
1296 		else
1297 			seq_printf(m, pt(Opt_fowner_eq), tbuf);
1298 		seq_puts(m, " ");
1299 	}
1300 
1301 	for (i = 0; i < MAX_LSM_RULES; i++) {
1302 		if (entry->lsm[i].rule) {
1303 			switch (i) {
1304 			case LSM_OBJ_USER:
1305 				seq_printf(m, pt(Opt_obj_user),
1306 					   (char *)entry->lsm[i].args_p);
1307 				break;
1308 			case LSM_OBJ_ROLE:
1309 				seq_printf(m, pt(Opt_obj_role),
1310 					   (char *)entry->lsm[i].args_p);
1311 				break;
1312 			case LSM_OBJ_TYPE:
1313 				seq_printf(m, pt(Opt_obj_type),
1314 					   (char *)entry->lsm[i].args_p);
1315 				break;
1316 			case LSM_SUBJ_USER:
1317 				seq_printf(m, pt(Opt_subj_user),
1318 					   (char *)entry->lsm[i].args_p);
1319 				break;
1320 			case LSM_SUBJ_ROLE:
1321 				seq_printf(m, pt(Opt_subj_role),
1322 					   (char *)entry->lsm[i].args_p);
1323 				break;
1324 			case LSM_SUBJ_TYPE:
1325 				seq_printf(m, pt(Opt_subj_type),
1326 					   (char *)entry->lsm[i].args_p);
1327 				break;
1328 			}
1329 		}
1330 	}
1331 	if (entry->flags & IMA_DIGSIG_REQUIRED)
1332 		seq_puts(m, "appraise_type=imasig ");
1333 	if (entry->flags & IMA_PERMIT_DIRECTIO)
1334 		seq_puts(m, "permit_directio ");
1335 	rcu_read_unlock();
1336 	seq_puts(m, "\n");
1337 	return 0;
1338 }
1339 #endif	/* CONFIG_IMA_READ_POLICY */
1340