security/integrity/ima/ima_policy.c

   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                         break;
 345                 case LSM_SUBJ_USER:
 346                 case LSM_SUBJ_ROLE:
 347                 case LSM_SUBJ_TYPE:
 348                         rc = security_filter_rule_match(secid,
 349                                                         rule->lsm[i].type,
 350                                                         Audit_equal,
 351                                                         rule->lsm[i].rule);
 352                 default:
 353                         break;
 354                 }
 355                 if ((rc < 0) && (!retried)) {
 356                         retried = 1;
 357                         ima_lsm_update_rules();
 358                         goto retry;
 359                 }
 360                 if (!rc)
 361                         return false;
 362         }
 363         return true;
 364 }
 365
 366 /*
 367  * In addition to knowing that we need to appraise the file in general,
 368  * we need to differentiate between calling hooks, for hook specific rules.
 369  */
 370 static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
 371 {
 372         if (!(rule->flags & IMA_FUNC))
 373                 return IMA_FILE_APPRAISE;
 374
 375         switch (func) {
 376         case MMAP_CHECK:
 377                 return IMA_MMAP_APPRAISE;
 378         case BPRM_CHECK:
 379                 return IMA_BPRM_APPRAISE;
 380         case CREDS_CHECK:
 381                 return IMA_CREDS_APPRAISE;
 382         case FILE_CHECK:
 383         case POST_SETATTR:
 384                 return IMA_FILE_APPRAISE;
 385         case MODULE_CHECK ... MAX_CHECK - 1:
 386         default:
 387                 return IMA_READ_APPRAISE;
 388         }
 389 }
 390
 391 /**
 392  * ima_match_policy - decision based on LSM and other conditions
 393  * @inode: pointer to an inode for which the policy decision is being made
 394  * @cred: pointer to a credentials structure for which the policy decision is
 395  *        being made
 396  * @secid: LSM secid of the task to be validated
 397  * @func: IMA hook identifier
 398  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
 399  * @pcr: set the pcr to extend
 400  *
 401  * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
 402  * conditions.
 403  *
 404  * Since the IMA policy may be updated multiple times we need to lock the
 405  * list when walking it.  Reads are many orders of magnitude more numerous
 406  * than writes so ima_match_policy() is classical RCU candidate.
 407  */
 408 int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 409                      enum ima_hooks func, int mask, int flags, int *pcr)
 410 {
 411         struct ima_rule_entry *entry;
 412         int action = 0, actmask = flags | (flags << 1);
 413
 414         rcu_read_lock();
 415         list_for_each_entry_rcu(entry, ima_rules, list) {
 416
 417                 if (!(entry->action & actmask))
 418                         continue;
 419
 420                 if (!ima_match_rules(entry, inode, cred, secid, func, mask))
 421                         continue;
 422
 423                 action |= entry->flags & IMA_ACTION_FLAGS;
 424
 425                 action |= entry->action & IMA_DO_MASK;
 426                 if (entry->action & IMA_APPRAISE) {
 427                         action |= get_subaction(entry, func);
 428                         action &= ~IMA_HASH;
 429                         if (ima_fail_unverifiable_sigs)
 430                                 action |= IMA_FAIL_UNVERIFIABLE_SIGS;
 431                 }
 432
 433                 if (entry->action & IMA_DO_MASK)
 434                         actmask &= ~(entry->action | entry->action << 1);
 435                 else
 436                         actmask &= ~(entry->action | entry->action >> 1);
 437
 438                 if ((pcr) && (entry->flags & IMA_PCR))
 439                         *pcr = entry->pcr;
 440
 441                 if (!actmask)
 442                         break;
 443         }
 444         rcu_read_unlock();
 445
 446         return action;
 447 }
 448
 449 /*
 450  * Initialize the ima_policy_flag variable based on the currently
 451  * loaded policy.  Based on this flag, the decision to short circuit
 452  * out of a function or not call the function in the first place
 453  * can be made earlier.
 454  */
 455 void ima_update_policy_flag(void)
 456 {
 457         struct ima_rule_entry *entry;
 458
 459         list_for_each_entry(entry, ima_rules, list) {
 460                 if (entry->action & IMA_DO_MASK)
 461                         ima_policy_flag |= entry->action;
 462         }
 463
 464         ima_appraise |= (build_ima_appraise | temp_ima_appraise);
 465         if (!ima_appraise)
 466                 ima_policy_flag &= ~IMA_APPRAISE;
 467 }
 468
 469 static int ima_appraise_flag(enum ima_hooks func)
 470 {
 471         if (func == MODULE_CHECK)
 472                 return IMA_APPRAISE_MODULES;
 473         else if (func == FIRMWARE_CHECK)
 474                 return IMA_APPRAISE_FIRMWARE;
 475         else if (func == POLICY_CHECK)
 476                 return IMA_APPRAISE_POLICY;
 477         else if (func == KEXEC_KERNEL_CHECK)
 478                 return IMA_APPRAISE_KEXEC;
 479         return 0;
 480 }
 481
 482 static void add_rules(struct ima_rule_entry *entries, int count,
 483                       enum policy_rule_list policy_rule)
 484 {
 485         int i = 0;
 486
 487         for (i = 0; i < count; i++) {
 488                 struct ima_rule_entry *entry;
 489
 490                 if (policy_rule & IMA_DEFAULT_POLICY)
 491                         list_add_tail(&entries[i].list, &ima_default_rules);
 492
 493                 if (policy_rule & IMA_CUSTOM_POLICY) {
 494                         entry = kmemdup(&entries[i], sizeof(*entry),
 495                                         GFP_KERNEL);
 496                         if (!entry)
 497                                 continue;
 498
 499                         list_add_tail(&entry->list, &ima_policy_rules);
 500                 }
 501                 if (entries[i].action == APPRAISE) {
 502                         temp_ima_appraise |= ima_appraise_flag(entries[i].func);
 503                         if (entries[i].func == POLICY_CHECK)
 504                                 temp_ima_appraise |= IMA_APPRAISE_POLICY;
 505                 }
 506         }
 507 }
 508
 509 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry);
 510
 511 static int __init ima_init_arch_policy(void)
 512 {
 513         const char * const *arch_rules;
 514         const char * const *rules;
 515         int arch_entries = 0;
 516         int i = 0;
 517
 518         arch_rules = arch_get_ima_policy();
 519         if (!arch_rules)
 520                 return arch_entries;
 521
 522         /* Get number of rules */
 523         for (rules = arch_rules; *rules != NULL; rules++)
 524                 arch_entries++;
 525
 526         arch_policy_entry = kcalloc(arch_entries + 1,
 527                                     sizeof(*arch_policy_entry), GFP_KERNEL);
 528         if (!arch_policy_entry)
 529                 return 0;
 530
 531         /* Convert each policy string rules to struct ima_rule_entry format */
 532         for (rules = arch_rules, i = 0; *rules != NULL; rules++) {
 533                 char rule[255];
 534                 int result;
 535
 536                 result = strlcpy(rule, *rules, sizeof(rule));
 537
 538                 INIT_LIST_HEAD(&arch_policy_entry[i].list);
 539                 result = ima_parse_rule(rule, &arch_policy_entry[i]);
 540                 if (result) {
 541                         pr_warn("Skipping unknown architecture policy rule: %s\n",
 542                                 rule);
 543                         memset(&arch_policy_entry[i], 0,
 544                                sizeof(*arch_policy_entry));
 545                         continue;
 546                 }
 547                 i++;
 548         }
 549         return i;
 550 }
 551
 552 /**
 553  * ima_init_policy - initialize the default measure rules.
 554  *
 555  * ima_rules points to either the ima_default_rules or the
 556  * the new ima_policy_rules.
 557  */
 558 void __init ima_init_policy(void)
 559 {
 560         int build_appraise_entries, arch_entries;
 561
 562         /* if !ima_policy, we load NO default rules */
 563         if (ima_policy)
 564                 add_rules(dont_measure_rules, ARRAY_SIZE(dont_measure_rules),
 565                           IMA_DEFAULT_POLICY);
 566
 567         switch (ima_policy) {
 568         case ORIGINAL_TCB:
 569                 add_rules(original_measurement_rules,
 570                           ARRAY_SIZE(original_measurement_rules),
 571                           IMA_DEFAULT_POLICY);
 572                 break;
 573         case DEFAULT_TCB:
 574                 add_rules(default_measurement_rules,
 575                           ARRAY_SIZE(default_measurement_rules),
 576                           IMA_DEFAULT_POLICY);
 577         default:
 578                 break;
 579         }
 580
 581         /*
 582          * Based on runtime secure boot flags, insert arch specific measurement
 583          * and appraise rules requiring file signatures for both the initial
 584          * and custom policies, prior to other appraise rules.
 585          * (Highest priority)
 586          */
 587         arch_entries = ima_init_arch_policy();
 588         if (!arch_entries)
 589                 pr_info("No architecture policies found\n");
 590         else
 591                 add_rules(arch_policy_entry, arch_entries,
 592                           IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY);
 593
 594         /*
 595          * Insert the builtin "secure_boot" policy rules requiring file
 596          * signatures, prior to other appraise rules.
 597          */
 598         if (ima_use_secure_boot)
 599                 add_rules(secure_boot_rules, ARRAY_SIZE(secure_boot_rules),
 600                           IMA_DEFAULT_POLICY);
 601
 602         /*
 603          * Insert the build time appraise rules requiring file signatures
 604          * for both the initial and custom policies, prior to other appraise
 605          * rules. As the secure boot rules includes all of the build time
 606          * rules, include either one or the other set of rules, but not both.
 607          */
 608         build_appraise_entries = ARRAY_SIZE(build_appraise_rules);
 609         if (build_appraise_entries) {
 610                 if (ima_use_secure_boot)
 611                         add_rules(build_appraise_rules, build_appraise_entries,
 612                                   IMA_CUSTOM_POLICY);
 613                 else
 614                         add_rules(build_appraise_rules, build_appraise_entries,
 615                                   IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY);
 616         }
 617
 618         if (ima_use_appraise_tcb)
 619                 add_rules(default_appraise_rules,
 620                           ARRAY_SIZE(default_appraise_rules),
 621                           IMA_DEFAULT_POLICY);
 622
 623         ima_rules = &ima_default_rules;
 624         ima_update_policy_flag();
 625 }
 626
 627 /* Make sure we have a valid policy, at least containing some rules. */
 628 int ima_check_policy(void)
 629 {
 630         if (list_empty(&ima_temp_rules))
 631                 return -EINVAL;
 632         return 0;
 633 }
 634
 635 /**
 636  * ima_update_policy - update default_rules with new measure rules
 637  *
 638  * Called on file .release to update the default rules with a complete new
 639  * policy.  What we do here is to splice ima_policy_rules and ima_temp_rules so
 640  * they make a queue.  The policy may be updated multiple times and this is the
 641  * RCU updater.
 642  *
 643  * Policy rules are never deleted so ima_policy_flag gets zeroed only once when
 644  * we switch from the default policy to user defined.
 645  */
 646 void ima_update_policy(void)
 647 {
 648         struct list_head *policy = &ima_policy_rules;
 649
 650         list_splice_tail_init_rcu(&ima_temp_rules, policy, synchronize_rcu);
 651
 652         if (ima_rules != policy) {
 653                 ima_policy_flag = 0;
 654                 ima_rules = policy;
 655
 656                 /*
 657                  * IMA architecture specific policy rules are specified
 658                  * as strings and converted to an array of ima_entry_rules
 659                  * on boot.  After loading a custom policy, free the
 660                  * architecture specific rules stored as an array.
 661                  */
 662                 kfree(arch_policy_entry);
 663         }
 664         ima_update_policy_flag();
 665 }
 666
 667 /* Keep the enumeration in sync with the policy_tokens! */
 668 enum {
 669         Opt_measure, Opt_dont_measure,
 670         Opt_appraise, Opt_dont_appraise,
 671         Opt_audit, Opt_hash, Opt_dont_hash,
 672         Opt_obj_user, Opt_obj_role, Opt_obj_type,
 673         Opt_subj_user, Opt_subj_role, Opt_subj_type,
 674         Opt_func, Opt_mask, Opt_fsmagic, Opt_fsname,
 675         Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq,
 676         Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt,
 677         Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
 678         Opt_appraise_type, Opt_permit_directio,
 679         Opt_pcr, Opt_err
 680 };
 681
 682 static const match_table_t policy_tokens = {
 683         {Opt_measure, "measure"},
 684         {Opt_dont_measure, "dont_measure"},
 685         {Opt_appraise, "appraise"},
 686         {Opt_dont_appraise, "dont_appraise"},
 687         {Opt_audit, "audit"},
 688         {Opt_hash, "hash"},
 689         {Opt_dont_hash, "dont_hash"},
 690         {Opt_obj_user, "obj_user=%s"},
 691         {Opt_obj_role, "obj_role=%s"},
 692         {Opt_obj_type, "obj_type=%s"},
 693         {Opt_subj_user, "subj_user=%s"},
 694         {Opt_subj_role, "subj_role=%s"},
 695         {Opt_subj_type, "subj_type=%s"},
 696         {Opt_func, "func=%s"},
 697         {Opt_mask, "mask=%s"},
 698         {Opt_fsmagic, "fsmagic=%s"},
 699         {Opt_fsname, "fsname=%s"},
 700         {Opt_fsuuid, "fsuuid=%s"},
 701         {Opt_uid_eq, "uid=%s"},
 702         {Opt_euid_eq, "euid=%s"},
 703         {Opt_fowner_eq, "fowner=%s"},
 704         {Opt_uid_gt, "uid>%s"},
 705         {Opt_euid_gt, "euid>%s"},
 706         {Opt_fowner_gt, "fowner>%s"},
 707         {Opt_uid_lt, "uid<%s"},
 708         {Opt_euid_lt, "euid<%s"},
 709         {Opt_fowner_lt, "fowner<%s"},
 710         {Opt_appraise_type, "appraise_type=%s"},
 711         {Opt_permit_directio, "permit_directio"},
 712         {Opt_pcr, "pcr=%s"},
 713         {Opt_err, NULL}
 714 };
 715
 716 static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 717                              substring_t *args, int lsm_rule, int audit_type)
 718 {
 719         int result;
 720
 721         if (entry->lsm[lsm_rule].rule)
 722                 return -EINVAL;
 723
 724         entry->lsm[lsm_rule].args_p = match_strdup(args);
 725         if (!entry->lsm[lsm_rule].args_p)
 726                 return -ENOMEM;
 727
 728         entry->lsm[lsm_rule].type = audit_type;
 729         result = security_filter_rule_init(entry->lsm[lsm_rule].type,
 730                                            Audit_equal,
 731                                            entry->lsm[lsm_rule].args_p,
 732                                            &entry->lsm[lsm_rule].rule);
 733         if (!entry->lsm[lsm_rule].rule) {
 734                 kfree(entry->lsm[lsm_rule].args_p);
 735                 return -EINVAL;
 736         }
 737
 738         return result;
 739 }
 740
 741 static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
 742                               bool (*rule_operator)(kuid_t, kuid_t))
 743 {
 744         if (!ab)
 745                 return;
 746
 747         if (rule_operator == &uid_gt)
 748                 audit_log_format(ab, "%s>", key);
 749         else if (rule_operator == &uid_lt)
 750                 audit_log_format(ab, "%s<", key);
 751         else
 752                 audit_log_format(ab, "%s=", key);
 753         audit_log_format(ab, "%s ", value);
 754 }
 755 static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
 756 {
 757         ima_log_string_op(ab, key, value, NULL);
 758 }
 759
 760 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 761 {
 762         struct audit_buffer *ab;
 763         char *from;
 764         char *p;
 765         bool uid_token;
 766         int result = 0;
 767
 768         ab = integrity_audit_log_start(audit_context(), GFP_KERNEL,
 769                                        AUDIT_INTEGRITY_POLICY_RULE);
 770
 771         entry->uid = INVALID_UID;
 772         entry->fowner = INVALID_UID;
 773         entry->uid_op = &uid_eq;
 774         entry->fowner_op = &uid_eq;
 775         entry->action = UNKNOWN;
 776         while ((p = strsep(&rule, " \t")) != NULL) {
 777                 substring_t args[MAX_OPT_ARGS];
 778                 int token;
 779                 unsigned long lnum;
 780
 781                 if (result < 0)
 782                         break;
 783                 if ((*p == '\0') || (*p == ' ') || (*p == '\t'))
 784                         continue;
 785                 token = match_token(p, policy_tokens, args);
 786                 switch (token) {
 787                 case Opt_measure:
 788                         ima_log_string(ab, "action", "measure");
 789
 790                         if (entry->action != UNKNOWN)
 791                                 result = -EINVAL;
 792
 793                         entry->action = MEASURE;
 794                         break;
 795                 case Opt_dont_measure:
 796                         ima_log_string(ab, "action", "dont_measure");
 797
 798                         if (entry->action != UNKNOWN)
 799                                 result = -EINVAL;
 800
 801                         entry->action = DONT_MEASURE;
 802                         break;
 803                 case Opt_appraise:
 804                         ima_log_string(ab, "action", "appraise");
 805
 806                         if (entry->action != UNKNOWN)
 807                                 result = -EINVAL;
 808
 809                         entry->action = APPRAISE;
 810                         break;
 811                 case Opt_dont_appraise:
 812                         ima_log_string(ab, "action", "dont_appraise");
 813
 814                         if (entry->action != UNKNOWN)
 815                                 result = -EINVAL;
 816
 817                         entry->action = DONT_APPRAISE;
 818                         break;
 819                 case Opt_audit:
 820                         ima_log_string(ab, "action", "audit");
 821
 822                         if (entry->action != UNKNOWN)
 823                                 result = -EINVAL;
 824
 825                         entry->action = AUDIT;
 826                         break;
 827                 case Opt_hash:
 828                         ima_log_string(ab, "action", "hash");
 829
 830                         if (entry->action != UNKNOWN)
 831                                 result = -EINVAL;
 832
 833                         entry->action = HASH;
 834                         break;
 835                 case Opt_dont_hash:
 836                         ima_log_string(ab, "action", "dont_hash");
 837
 838                         if (entry->action != UNKNOWN)
 839                                 result = -EINVAL;
 840
 841                         entry->action = DONT_HASH;
 842                         break;
 843                 case Opt_func:
 844                         ima_log_string(ab, "func", args[0].from);
 845
 846                         if (entry->func)
 847                                 result = -EINVAL;
 848
 849                         if (strcmp(args[0].from, "FILE_CHECK") == 0)
 850                                 entry->func = FILE_CHECK;
 851                         /* PATH_CHECK is for backwards compat */
 852                         else if (strcmp(args[0].from, "PATH_CHECK") == 0)
 853                                 entry->func = FILE_CHECK;
 854                         else if (strcmp(args[0].from, "MODULE_CHECK") == 0)
 855                                 entry->func = MODULE_CHECK;
 856                         else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0)
 857                                 entry->func = FIRMWARE_CHECK;
 858                         else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
 859                                 || (strcmp(args[0].from, "MMAP_CHECK") == 0))
 860                                 entry->func = MMAP_CHECK;
 861                         else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
 862                                 entry->func = BPRM_CHECK;
 863                         else if (strcmp(args[0].from, "CREDS_CHECK") == 0)
 864                                 entry->func = CREDS_CHECK;
 865                         else if (strcmp(args[0].from, "KEXEC_KERNEL_CHECK") ==
 866                                  0)
 867                                 entry->func = KEXEC_KERNEL_CHECK;
 868                         else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK")
 869                                  == 0)
 870                                 entry->func = KEXEC_INITRAMFS_CHECK;
 871                         else if (strcmp(args[0].from, "POLICY_CHECK") == 0)
 872                                 entry->func = POLICY_CHECK;
 873                         else
 874                                 result = -EINVAL;
 875                         if (!result)
 876                                 entry->flags |= IMA_FUNC;
 877                         break;
 878                 case Opt_mask:
 879                         ima_log_string(ab, "mask", args[0].from);
 880
 881                         if (entry->mask)
 882                                 result = -EINVAL;
 883
 884                         from = args[0].from;
 885                         if (*from == '^')
 886                                 from++;
 887
 888                         if ((strcmp(from, "MAY_EXEC")) == 0)
 889                                 entry->mask = MAY_EXEC;
 890                         else if (strcmp(from, "MAY_WRITE") == 0)
 891                                 entry->mask = MAY_WRITE;
 892                         else if (strcmp(from, "MAY_READ") == 0)
 893                                 entry->mask = MAY_READ;
 894                         else if (strcmp(from, "MAY_APPEND") == 0)
 895                                 entry->mask = MAY_APPEND;
 896                         else
 897                                 result = -EINVAL;
 898                         if (!result)
 899                                 entry->flags |= (*args[0].from == '^')
 900                                      ? IMA_INMASK : IMA_MASK;
 901                         break;
 902                 case Opt_fsmagic:
 903                         ima_log_string(ab, "fsmagic", args[0].from);
 904
 905                         if (entry->fsmagic) {
 906                                 result = -EINVAL;
 907                                 break;
 908                         }
 909
 910                         result = kstrtoul(args[0].from, 16, &entry->fsmagic);
 911                         if (!result)
 912                                 entry->flags |= IMA_FSMAGIC;
 913                         break;
 914                 case Opt_fsname:
 915                         ima_log_string(ab, "fsname", args[0].from);
 916
 917                         entry->fsname = kstrdup(args[0].from, GFP_KERNEL);
 918                         if (!entry->fsname) {
 919                                 result = -ENOMEM;
 920                                 break;
 921                         }
 922                         result = 0;
 923                         entry->flags |= IMA_FSNAME;
 924                         break;
 925                 case Opt_fsuuid:
 926                         ima_log_string(ab, "fsuuid", args[0].from);
 927
 928                         if (!uuid_is_null(&entry->fsuuid)) {
 929                                 result = -EINVAL;
 930                                 break;
 931                         }
 932
 933                         result = uuid_parse(args[0].from, &entry->fsuuid);
 934                         if (!result)
 935                                 entry->flags |= IMA_FSUUID;
 936                         break;
 937                 case Opt_uid_gt:
 938                 case Opt_euid_gt:
 939                         entry->uid_op = &uid_gt;
 940                         /* fall through */
 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                         /* fall through */
 946                 case Opt_uid_eq:
 947                 case Opt_euid_eq:
 948                         uid_token = (token == Opt_uid_eq) ||
 949                                     (token == Opt_uid_gt) ||
 950                                     (token == Opt_uid_lt);
 951
 952                         ima_log_string_op(ab, uid_token ? "uid" : "euid",
 953                                           args[0].from, entry->uid_op);
 954
 955                         if (uid_valid(entry->uid)) {
 956                                 result = -EINVAL;
 957                                 break;
 958                         }
 959
 960                         result = kstrtoul(args[0].from, 10, &lnum);
 961                         if (!result) {
 962                                 entry->uid = make_kuid(current_user_ns(),
 963                                                        (uid_t) lnum);
 964                                 if (!uid_valid(entry->uid) ||
 965                                     (uid_t)lnum != lnum)
 966                                         result = -EINVAL;
 967                                 else
 968                                         entry->flags |= uid_token
 969                                             ? IMA_UID : IMA_EUID;
 970                         }
 971                         break;
 972                 case Opt_fowner_gt:
 973                         entry->fowner_op = &uid_gt;
 974                         /* fall through */
 975                 case Opt_fowner_lt:
 976                         if (token == Opt_fowner_lt)
 977                                 entry->fowner_op = &uid_lt;
 978                         /* fall through */
 979                 case Opt_fowner_eq:
 980                         ima_log_string_op(ab, "fowner", args[0].from,
 981                                           entry->fowner_op);
 982
 983                         if (uid_valid(entry->fowner)) {
 984                                 result = -EINVAL;
 985                                 break;
 986                         }
 987
 988                         result = kstrtoul(args[0].from, 10, &lnum);
 989                         if (!result) {
 990                                 entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
 991                                 if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
 992                                         result = -EINVAL;
 993                                 else
 994                                         entry->flags |= IMA_FOWNER;
 995                         }
 996                         break;
 997                 case Opt_obj_user:
 998                         ima_log_string(ab, "obj_user", args[0].from);
 999                         result = ima_lsm_rule_init(entry, args,
1000                                                    LSM_OBJ_USER,
1001                                                    AUDIT_OBJ_USER);
1002                         break;
1003                 case Opt_obj_role:
1004                         ima_log_string(ab, "obj_role", args[0].from);
1005                         result = ima_lsm_rule_init(entry, args,
1006                                                    LSM_OBJ_ROLE,
1007                                                    AUDIT_OBJ_ROLE);
1008                         break;
1009                 case Opt_obj_type:
1010                         ima_log_string(ab, "obj_type", args[0].from);
1011                         result = ima_lsm_rule_init(entry, args,
1012                                                    LSM_OBJ_TYPE,
1013                                                    AUDIT_OBJ_TYPE);
1014                         break;
1015                 case Opt_subj_user:
1016                         ima_log_string(ab, "subj_user", args[0].from);
1017                         result = ima_lsm_rule_init(entry, args,
1018                                                    LSM_SUBJ_USER,
1019                                                    AUDIT_SUBJ_USER);
1020                         break;
1021                 case Opt_subj_role:
1022                         ima_log_string(ab, "subj_role", args[0].from);
1023                         result = ima_lsm_rule_init(entry, args,
1024                                                    LSM_SUBJ_ROLE,
1025                                                    AUDIT_SUBJ_ROLE);
1026                         break;
1027                 case Opt_subj_type:
1028                         ima_log_string(ab, "subj_type", args[0].from);
1029                         result = ima_lsm_rule_init(entry, args,
1030                                                    LSM_SUBJ_TYPE,
1031                                                    AUDIT_SUBJ_TYPE);
1032                         break;
1033                 case Opt_appraise_type:
1034                         if (entry->action != APPRAISE) {
1035                                 result = -EINVAL;
1036                                 break;
1037                         }
1038
1039                         ima_log_string(ab, "appraise_type", args[0].from);
1040                         if ((strcmp(args[0].from, "imasig")) == 0)
1041                                 entry->flags |= IMA_DIGSIG_REQUIRED;
1042                         else
1043                                 result = -EINVAL;
1044                         break;
1045                 case Opt_permit_directio:
1046                         entry->flags |= IMA_PERMIT_DIRECTIO;
1047                         break;
1048                 case Opt_pcr:
1049                         if (entry->action != MEASURE) {
1050                                 result = -EINVAL;
1051                                 break;
1052                         }
1053                         ima_log_string(ab, "pcr", args[0].from);
1054
1055                         result = kstrtoint(args[0].from, 10, &entry->pcr);
1056                         if (result || INVALID_PCR(entry->pcr))
1057                                 result = -EINVAL;
1058                         else
1059                                 entry->flags |= IMA_PCR;
1060
1061                         break;
1062                 case Opt_err:
1063                         ima_log_string(ab, "UNKNOWN", p);
1064                         result = -EINVAL;
1065                         break;
1066                 }
1067         }
1068         if (!result && (entry->action == UNKNOWN))
1069                 result = -EINVAL;
1070         else if (entry->action == APPRAISE)
1071                 temp_ima_appraise |= ima_appraise_flag(entry->func);
1072
1073         audit_log_format(ab, "res=%d", !result);
1074         audit_log_end(ab);
1075         return result;
1076 }
1077
1078 /**
1079  * ima_parse_add_rule - add a rule to ima_policy_rules
1080  * @rule - ima measurement policy rule
1081  *
1082  * Avoid locking by allowing just one writer at a time in ima_write_policy()
1083  * Returns the length of the rule parsed, an error code on failure
1084  */
1085 ssize_t ima_parse_add_rule(char *rule)
1086 {
1087         static const char op[] = "update_policy";
1088         char *p;
1089         struct ima_rule_entry *entry;
1090         ssize_t result, len;
1091         int audit_info = 0;
1092
1093         p = strsep(&rule, "\n");
1094         len = strlen(p) + 1;
1095         p += strspn(p, " \t");
1096
1097         if (*p == '#' || *p == '\0')
1098                 return len;
1099
1100         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1101         if (!entry) {
1102                 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
1103                                     NULL, op, "-ENOMEM", -ENOMEM, audit_info);
1104                 return -ENOMEM;
1105         }
1106
1107         INIT_LIST_HEAD(&entry->list);
1108
1109         result = ima_parse_rule(p, entry);
1110         if (result) {
1111                 kfree(entry);
1112                 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
1113                                     NULL, op, "invalid-policy", result,
1114                                     audit_info);
1115                 return result;
1116         }
1117
1118         list_add_tail(&entry->list, &ima_temp_rules);
1119
1120         return len;
1121 }
1122
1123 /**
1124  * ima_delete_rules() called to cleanup invalid in-flight policy.
1125  * We don't need locking as we operate on the temp list, which is
1126  * different from the active one.  There is also only one user of
1127  * ima_delete_rules() at a time.
1128  */
1129 void ima_delete_rules(void)
1130 {
1131         struct ima_rule_entry *entry, *tmp;
1132         int i;
1133
1134         temp_ima_appraise = 0;
1135         list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) {
1136                 for (i = 0; i < MAX_LSM_RULES; i++)
1137                         kfree(entry->lsm[i].args_p);
1138
1139                 list_del(&entry->list);
1140                 kfree(entry);
1141         }
1142 }
1143
1144 #ifdef  CONFIG_IMA_READ_POLICY
1145 enum {
1146         mask_exec = 0, mask_write, mask_read, mask_append
1147 };
1148
1149 static const char *const mask_tokens[] = {
1150         "^MAY_EXEC",
1151         "^MAY_WRITE",
1152         "^MAY_READ",
1153         "^MAY_APPEND"
1154 };
1155
1156 #define __ima_hook_stringify(str)       (#str),
1157
1158 static const char *const func_tokens[] = {
1159         __ima_hooks(__ima_hook_stringify)
1160 };
1161
1162 void *ima_policy_start(struct seq_file *m, loff_t *pos)
1163 {
1164         loff_t l = *pos;
1165         struct ima_rule_entry *entry;
1166
1167         rcu_read_lock();
1168         list_for_each_entry_rcu(entry, ima_rules, list) {
1169                 if (!l--) {
1170                         rcu_read_unlock();
1171                         return entry;
1172                 }
1173         }
1174         rcu_read_unlock();
1175         return NULL;
1176 }
1177
1178 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos)
1179 {
1180         struct ima_rule_entry *entry = v;
1181
1182         rcu_read_lock();
1183         entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list);
1184         rcu_read_unlock();
1185         (*pos)++;
1186
1187         return (&entry->list == ima_rules) ? NULL : entry;
1188 }
1189
1190 void ima_policy_stop(struct seq_file *m, void *v)
1191 {
1192 }
1193
1194 #define pt(token)       policy_tokens[token].pattern
1195 #define mt(token)       mask_tokens[token]
1196
1197 /*
1198  * policy_func_show - display the ima_hooks policy rule
1199  */
1200 static void policy_func_show(struct seq_file *m, enum ima_hooks func)
1201 {
1202         if (func > 0 && func < MAX_CHECK)
1203                 seq_printf(m, "func=%s ", func_tokens[func]);
1204         else
1205                 seq_printf(m, "func=%d ", func);
1206 }
1207
1208 int ima_policy_show(struct seq_file *m, void *v)
1209 {
1210         struct ima_rule_entry *entry = v;
1211         int i;
1212         char tbuf[64] = {0,};
1213         int offset = 0;
1214
1215         rcu_read_lock();
1216
1217         if (entry->action & MEASURE)
1218                 seq_puts(m, pt(Opt_measure));
1219         if (entry->action & DONT_MEASURE)
1220                 seq_puts(m, pt(Opt_dont_measure));
1221         if (entry->action & APPRAISE)
1222                 seq_puts(m, pt(Opt_appraise));
1223         if (entry->action & DONT_APPRAISE)
1224                 seq_puts(m, pt(Opt_dont_appraise));
1225         if (entry->action & AUDIT)
1226                 seq_puts(m, pt(Opt_audit));
1227         if (entry->action & HASH)
1228                 seq_puts(m, pt(Opt_hash));
1229         if (entry->action & DONT_HASH)
1230                 seq_puts(m, pt(Opt_dont_hash));
1231
1232         seq_puts(m, " ");
1233
1234         if (entry->flags & IMA_FUNC)
1235                 policy_func_show(m, entry->func);
1236
1237         if ((entry->flags & IMA_MASK) || (entry->flags & IMA_INMASK)) {
1238                 if (entry->flags & IMA_MASK)
1239                         offset = 1;
1240                 if (entry->mask & MAY_EXEC)
1241                         seq_printf(m, pt(Opt_mask), mt(mask_exec) + offset);
1242                 if (entry->mask & MAY_WRITE)
1243                         seq_printf(m, pt(Opt_mask), mt(mask_write) + offset);
1244                 if (entry->mask & MAY_READ)
1245                         seq_printf(m, pt(Opt_mask), mt(mask_read) + offset);
1246                 if (entry->mask & MAY_APPEND)
1247                         seq_printf(m, pt(Opt_mask), mt(mask_append) + offset);
1248                 seq_puts(m, " ");
1249         }
1250
1251         if (entry->flags & IMA_FSMAGIC) {
1252                 snprintf(tbuf, sizeof(tbuf), "0x%lx", entry->fsmagic);
1253                 seq_printf(m, pt(Opt_fsmagic), tbuf);
1254                 seq_puts(m, " ");
1255         }
1256
1257         if (entry->flags & IMA_FSNAME) {
1258                 snprintf(tbuf, sizeof(tbuf), "%s", entry->fsname);
1259                 seq_printf(m, pt(Opt_fsname), tbuf);
1260                 seq_puts(m, " ");
1261         }
1262
1263         if (entry->flags & IMA_PCR) {
1264                 snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
1265                 seq_printf(m, pt(Opt_pcr), tbuf);
1266                 seq_puts(m, " ");
1267         }
1268
1269         if (entry->flags & IMA_FSUUID) {
1270                 seq_printf(m, "fsuuid=%pU", &entry->fsuuid);
1271                 seq_puts(m, " ");
1272         }
1273
1274         if (entry->flags & IMA_UID) {
1275                 snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
1276                 if (entry->uid_op == &uid_gt)
1277                         seq_printf(m, pt(Opt_uid_gt), tbuf);
1278                 else if (entry->uid_op == &uid_lt)
1279                         seq_printf(m, pt(Opt_uid_lt), tbuf);
1280                 else
1281                         seq_printf(m, pt(Opt_uid_eq), tbuf);
1282                 seq_puts(m, " ");
1283         }
1284
1285         if (entry->flags & IMA_EUID) {
1286                 snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
1287                 if (entry->uid_op == &uid_gt)
1288                         seq_printf(m, pt(Opt_euid_gt), tbuf);
1289                 else if (entry->uid_op == &uid_lt)
1290                         seq_printf(m, pt(Opt_euid_lt), tbuf);
1291                 else
1292                         seq_printf(m, pt(Opt_euid_eq), tbuf);
1293                 seq_puts(m, " ");
1294         }
1295
1296         if (entry->flags & IMA_FOWNER) {
1297                 snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner));
1298                 if (entry->fowner_op == &uid_gt)
1299                         seq_printf(m, pt(Opt_fowner_gt), tbuf);
1300                 else if (entry->fowner_op == &uid_lt)
1301                         seq_printf(m, pt(Opt_fowner_lt), tbuf);
1302                 else
1303                         seq_printf(m, pt(Opt_fowner_eq), tbuf);
1304                 seq_puts(m, " ");
1305         }
1306
1307         for (i = 0; i < MAX_LSM_RULES; i++) {
1308                 if (entry->lsm[i].rule) {
1309                         switch (i) {
1310                         case LSM_OBJ_USER:
1311                                 seq_printf(m, pt(Opt_obj_user),
1312                                            (char *)entry->lsm[i].args_p);
1313                                 break;
1314                         case LSM_OBJ_ROLE:
1315                                 seq_printf(m, pt(Opt_obj_role),
1316                                            (char *)entry->lsm[i].args_p);
1317                                 break;
1318                         case LSM_OBJ_TYPE:
1319                                 seq_printf(m, pt(Opt_obj_type),
1320                                            (char *)entry->lsm[i].args_p);
1321                                 break;
1322                         case LSM_SUBJ_USER:
1323                                 seq_printf(m, pt(Opt_subj_user),
1324                                            (char *)entry->lsm[i].args_p);
1325                                 break;
1326                         case LSM_SUBJ_ROLE:
1327                                 seq_printf(m, pt(Opt_subj_role),
1328                                            (char *)entry->lsm[i].args_p);
1329                                 break;
1330                         case LSM_SUBJ_TYPE:
1331                                 seq_printf(m, pt(Opt_subj_type),
1332                                            (char *)entry->lsm[i].args_p);
1333                                 break;
1334                         }
1335                 }
1336         }
1337         if (entry->flags & IMA_DIGSIG_REQUIRED)
1338                 seq_puts(m, "appraise_type=imasig ");
1339         if (entry->flags & IMA_PERMIT_DIRECTIO)
1340                 seq_puts(m, "permit_directio ");
1341         rcu_read_unlock();
1342         seq_puts(m, "\n");
1343         return 0;
1344 }
1345 #endif  /* CONFIG_IMA_READ_POLICY */