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