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