security/integrity/ima/ima_policy.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2008 IBM Corporation
   4  * Author: Mimi Zohar <zohar@us.ibm.com>
   5  *
   6  * ima_policy.c
   7  *      - initialize default measure policy rules
   8  */
   9 #include <linux/init.h>
  10 #include <linux/list.h>
  11 #include <linux/fs.h>
  12 #include <linux/security.h>
  13 #include <linux/magic.h>
  14 #include <linux/parser.h>
  15 #include <linux/slab.h>
  16 #include <linux/rculist.h>
  17 #include <linux/genhd.h>
  18 #include <linux/seq_file.h>
  19 #include <linux/ima.h>
  20
  21 #include "ima.h"
  22
  23 /* flags definitions */
  24 #define IMA_FUNC        0x0001
  25 #define IMA_MASK        0x0002
  26 #define IMA_FSMAGIC     0x0004
  27 #define IMA_UID         0x0008
  28 #define IMA_FOWNER      0x0010
  29 #define IMA_FSUUID      0x0020
  30 #define IMA_INMASK      0x0040
  31 #define IMA_EUID        0x0080
  32 #define IMA_PCR         0x0100
  33 #define IMA_FSNAME      0x0200
  34
  35 #define UNKNOWN         0
  36 #define MEASURE         0x0001  /* same as IMA_MEASURE */
  37 #define DONT_MEASURE    0x0002
  38 #define APPRAISE        0x0004  /* same as IMA_APPRAISE */
  39 #define DONT_APPRAISE   0x0008
  40 #define AUDIT           0x0040
  41 #define HASH            0x0100
  42 #define DONT_HASH       0x0200
  43
  44 #define INVALID_PCR(a) (((a) < 0) || \
  45         (a) >= (FIELD_SIZEOF(struct integrity_iint_cache, measured_pcrs) * 8))
  46
  47 int ima_policy_flag;
  48 static int temp_ima_appraise;
  49 static int build_ima_appraise __ro_after_init;
  50
  51 #define MAX_LSM_RULES 6
  52 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
  53         LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
  54 };
  55
  56 enum policy_types { ORIGINAL_TCB = 1, DEFAULT_TCB };
  57
  58 enum policy_rule_list { IMA_DEFAULT_POLICY = 1, IMA_CUSTOM_POLICY };
  59
  60 struct ima_rule_entry {
  61         struct list_head list;
  62         int action;
  63         unsigned int flags;
  64         enum ima_hooks func;
  65         int mask;
  66         unsigned long fsmagic;
  67         uuid_t fsuuid;
  68         kuid_t uid;
  69         kuid_t fowner;
  70         bool (*uid_op)(kuid_t, kuid_t);    /* Handlers for operators       */
  71         bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
  72         int pcr;
  73         struct {
  74                 void *rule;     /* LSM file metadata specific */
  75                 void *args_p;   /* audit value */
  76                 int type;       /* audit type */
  77         } lsm[MAX_LSM_RULES];
  78         char *fsname;
  79 };
  80
  81 /*
  82  * Without LSM specific knowledge, the default policy can only be
  83  * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
  84  */
  85
  86 /*
  87  * The minimum rule set to allow for full TCB coverage.  Measures all files
  88  * opened or mmap for exec and everything read by root.  Dangerous because
  89  * normal users can easily run the machine out of memory simply building
  90  * and running executables.
  91  */
  92 static struct ima_rule_entry dont_measure_rules[] __ro_after_init = {
  93         {.action = DONT_MEASURE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
  94         {.action = DONT_MEASURE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
  95         {.action = DONT_MEASURE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
  96         {.action = DONT_MEASURE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
  97         {.action = DONT_MEASURE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC},
  98         {.action = DONT_MEASURE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
  99         {.action = DONT_MEASURE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
 100         {.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
 101         {.action = DONT_MEASURE, .fsmagic = SMACK_MAGIC, .flags = IMA_FSMAGIC},
 102         {.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC,
 103          .flags = IMA_FSMAGIC},
 104         {.action = DONT_MEASURE, .fsmagic = CGROUP2_SUPER_MAGIC,
 105          .flags = IMA_FSMAGIC},
 106         {.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
 107         {.action = DONT_MEASURE, .fsmagic = EFIVARFS_MAGIC, .flags = IMA_FSMAGIC}
 108 };
 109
 110 static struct ima_rule_entry original_measurement_rules[] __ro_after_init = {
 111         {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
 112          .flags = IMA_FUNC | IMA_MASK},
 113         {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
 114          .flags = IMA_FUNC | IMA_MASK},
 115         {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
 116          .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq,
 117          .flags = IMA_FUNC | IMA_MASK | IMA_UID},
 118         {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
 119         {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
 120 };
 121
 122 static struct ima_rule_entry default_measurement_rules[] __ro_after_init = {
 123         {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
 124          .flags = IMA_FUNC | IMA_MASK},
 125         {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
 126          .flags = IMA_FUNC | IMA_MASK},
 127         {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
 128          .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq,
 129          .flags = IMA_FUNC | IMA_INMASK | IMA_EUID},
 130         {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
 131          .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq,
 132          .flags = IMA_FUNC | IMA_INMASK | IMA_UID},
 133         {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
 134         {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
 135         {.action = MEASURE, .func = POLICY_CHECK, .flags = IMA_FUNC},
 136 };
 137
 138 static struct ima_rule_entry default_appraise_rules[] __ro_after_init = {
 139         {.action = DONT_APPRAISE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 140         {.action = DONT_APPRAISE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
 141         {.action = DONT_APPRAISE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
 142         {.action = DONT_APPRAISE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
 143         {.action = DONT_APPRAISE, .fsmagic = RAMFS_MAGIC, .flags = IMA_FSMAGIC},
 144         {.action = DONT_APPRAISE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 145         {.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
 146         {.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
 147         {.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
 148         {.action = DONT_APPRAISE, .fsmagic = SMACK_MAGIC, .flags = IMA_FSMAGIC},
 149         {.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
 150         {.action = DONT_APPRAISE, .fsmagic = EFIVARFS_MAGIC, .flags = IMA_FSMAGIC},
 151         {.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 152         {.action = DONT_APPRAISE, .fsmagic = CGROUP2_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 153 #ifdef CONFIG_IMA_WRITE_POLICY
 154         {.action = APPRAISE, .func = POLICY_CHECK,
 155         .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 156 #endif
 157 #ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT
 158         {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .fowner_op = &uid_eq,
 159          .flags = IMA_FOWNER},
 160 #else
 161         /* force signature */
 162         {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .fowner_op = &uid_eq,
 163          .flags = IMA_FOWNER | IMA_DIGSIG_REQUIRED},
 164 #endif
 165 };
 166
 167 static struct ima_rule_entry build_appraise_rules[] __ro_after_init = {
 168 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_MODULE_SIGS
 169         {.action = APPRAISE, .func = MODULE_CHECK,
 170          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 171 #endif
 172 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
 173         {.action = APPRAISE, .func = FIRMWARE_CHECK,
 174          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 175 #endif
 176 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_KEXEC_SIGS
 177         {.action = APPRAISE, .func = KEXEC_KERNEL_CHECK,
 178          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 179 #endif
 180 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_POLICY_SIGS
 181         {.action = APPRAISE, .func = POLICY_CHECK,
 182          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 183 #endif
 184 };
 185
 186 static struct ima_rule_entry secure_boot_rules[] __ro_after_init = {
 187         {.action = APPRAISE, .func = MODULE_CHECK,
 188          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 189         {.action = APPRAISE, .func = FIRMWARE_CHECK,
 190          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 191         {.action = APPRAISE, .func = KEXEC_KERNEL_CHECK,
 192          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 193         {.action = APPRAISE, .func = POLICY_CHECK,
 194          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 195 };
 196
 197 /* An array of architecture specific rules */
 198 struct ima_rule_entry *arch_policy_entry __ro_after_init;
 199
 200 static LIST_HEAD(ima_default_rules);
 201 static LIST_HEAD(ima_policy_rules);
 202 static LIST_HEAD(ima_temp_rules);
 203 static struct list_head *ima_rules;
 204
 205 static int ima_policy __initdata;
 206
 207 static int __init default_measure_policy_setup(char *str)
 208 {
 209         if (ima_policy)
 210                 return 1;
 211
 212         ima_policy = ORIGINAL_TCB;
 213         return 1;
 214 }
 215 __setup("ima_tcb", default_measure_policy_setup);
 216
 217 static bool ima_use_appraise_tcb __initdata;
 218 static bool ima_use_secure_boot __initdata;
 219 static bool ima_fail_unverifiable_sigs __ro_after_init;
 220 static int __init policy_setup(char *str)
 221 {
 222         char *p;
 223
 224         while ((p = strsep(&str, " |\n")) != NULL) {
 225                 if (*p == ' ')
 226                         continue;
 227                 if ((strcmp(p, "tcb") == 0) && !ima_policy)
 228                         ima_policy = DEFAULT_TCB;
 229                 else if (strcmp(p, "appraise_tcb") == 0)
 230                         ima_use_appraise_tcb = true;
 231                 else if (strcmp(p, "secure_boot") == 0)
 232                         ima_use_secure_boot = true;
 233                 else if (strcmp(p, "fail_securely") == 0)
 234                         ima_fail_unverifiable_sigs = true;
 235         }
 236
 237         return 1;
 238 }
 239 __setup("ima_policy=", policy_setup);
 240
 241 static int __init default_appraise_policy_setup(char *str)
 242 {
 243         ima_use_appraise_tcb = true;
 244         return 1;
 245 }
 246 __setup("ima_appraise_tcb", default_appraise_policy_setup);
 247
 248 /*
 249  * The LSM policy can be reloaded, leaving the IMA LSM based rules referring
 250  * to the old, stale LSM policy.  Update the IMA LSM based rules to reflect
 251  * the reloaded LSM policy.  We assume the rules still exist; and BUG_ON() if
 252  * they don't.
 253  */
 254 static void ima_lsm_update_rules(void)
 255 {
 256         struct ima_rule_entry *entry;
 257         int result;
 258         int i;
 259
 260         list_for_each_entry(entry, &ima_policy_rules, list) {
 261                 for (i = 0; i < MAX_LSM_RULES; i++) {
 262                         if (!entry->lsm[i].rule)
 263                                 continue;
 264                         result = security_filter_rule_init(entry->lsm[i].type,
 265                                                            Audit_equal,
 266                                                            entry->lsm[i].args_p,
 267                                                            &entry->lsm[i].rule);
 268                         BUG_ON(!entry->lsm[i].rule);
 269                 }
 270         }
 271 }
 272
 273 /**
 274  * ima_match_rules - determine whether an inode matches the measure rule.
 275  * @rule: a pointer to a rule
 276  * @inode: a pointer to an inode
 277  * @cred: a pointer to a credentials structure for user validation
 278  * @secid: the secid of the task to be validated
 279  * @func: LIM hook identifier
 280  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
 281  *
 282  * Returns true on rule match, false on failure.
 283  */
 284 static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 285                             const struct cred *cred, u32 secid,
 286                             enum ima_hooks func, int mask)
 287 {
 288         int i;
 289
 290         if ((rule->flags & IMA_FUNC) &&
 291             (rule->func != func && func != POST_SETATTR))
 292                 return false;
 293         if ((rule->flags & IMA_MASK) &&
 294             (rule->mask != mask && func != POST_SETATTR))
 295                 return false;
 296         if ((rule->flags & IMA_INMASK) &&
 297             (!(rule->mask & mask) && func != POST_SETATTR))
 298                 return false;
 299         if ((rule->flags & IMA_FSMAGIC)
 300             && rule->fsmagic != inode->i_sb->s_magic)
 301                 return false;
 302         if ((rule->flags & IMA_FSNAME)
 303             && strcmp(rule->fsname, inode->i_sb->s_type->name))
 304                 return false;
 305         if ((rule->flags & IMA_FSUUID) &&
 306             !uuid_equal(&rule->fsuuid, &inode->i_sb->s_uuid))
 307                 return false;
 308         if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
 309                 return false;
 310         if (rule->flags & IMA_EUID) {
 311                 if (has_capability_noaudit(current, CAP_SETUID)) {
 312                         if (!rule->uid_op(cred->euid, rule->uid)
 313                             && !rule->uid_op(cred->suid, rule->uid)
 314                             && !rule->uid_op(cred->uid, rule->uid))
 315                                 return false;
 316                 } else if (!rule->uid_op(cred->euid, rule->uid))
 317                         return false;
 318         }
 319
 320         if ((rule->flags & IMA_FOWNER) &&
 321             !rule->fowner_op(inode->i_uid, rule->fowner))
 322                 return false;
 323         for (i = 0; i < MAX_LSM_RULES; i++) {
 324                 int rc = 0;
 325                 u32 osid;
 326                 int retried = 0;
 327
 328                 if (!rule->lsm[i].rule)
 329                         continue;
 330 retry:
 331                 switch (i) {
 332                 case LSM_OBJ_USER:
 333                 case LSM_OBJ_ROLE:
 334                 case LSM_OBJ_TYPE:
 335                         security_inode_getsecid(inode, &osid);
 336                         rc = security_filter_rule_match(osid,
 337                                                         rule->lsm[i].type,
 338                                                         Audit_equal,
 339                                                         rule->lsm[i].rule);
 340                         break;
 341                 case LSM_SUBJ_USER:
 342                 case LSM_SUBJ_ROLE:
 343                 case LSM_SUBJ_TYPE:
 344                         rc = security_filter_rule_match(secid,
 345                                                         rule->lsm[i].type,
 346                                                         Audit_equal,
 347                                                         rule->lsm[i].rule);
 348                 default:
 349                         break;
 350                 }
 351                 if ((rc < 0) && (!retried)) {
 352                         retried = 1;
 353                         ima_lsm_update_rules();
 354                         goto retry;
 355                 }
 356                 if (!rc)
 357                         return false;
 358         }
 359         return true;
 360 }
 361
 362 /*
 363  * In addition to knowing that we need to appraise the file in general,
 364  * we need to differentiate between calling hooks, for hook specific rules.
 365  */
 366 static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
 367 {
 368         if (!(rule->flags & IMA_FUNC))
 369                 return IMA_FILE_APPRAISE;
 370
 371         switch (func) {
 372         case MMAP_CHECK:
 373                 return IMA_MMAP_APPRAISE;
 374         case BPRM_CHECK:
 375                 return IMA_BPRM_APPRAISE;
 376         case CREDS_CHECK:
 377                 return IMA_CREDS_APPRAISE;
 378         case FILE_CHECK:
 379         case POST_SETATTR:
 380                 return IMA_FILE_APPRAISE;
 381         case MODULE_CHECK ... MAX_CHECK - 1:
 382         default:
 383                 return IMA_READ_APPRAISE;
 384         }
 385 }
 386
 387 /**
 388  * ima_match_policy - decision based on LSM and other conditions
 389  * @inode: pointer to an inode for which the policy decision is being made
 390  * @cred: pointer to a credentials structure for which the policy decision is
 391  *        being made
 392  * @secid: LSM secid of the task to be validated
 393  * @func: IMA hook identifier
 394  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
 395  * @pcr: set the pcr to extend
 396  *
 397  * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
 398  * conditions.
 399  *
 400  * Since the IMA policy may be updated multiple times we need to lock the
 401  * list when walking it.  Reads are many orders of magnitude more numerous
 402  * than writes so ima_match_policy() is classical RCU candidate.
 403  */
 404 int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 405                      enum ima_hooks func, int mask, int flags, int *pcr)
 406 {
 407         struct ima_rule_entry *entry;
 408         int action = 0, actmask = flags | (flags << 1);
 409
 410         rcu_read_lock();
 411         list_for_each_entry_rcu(entry, ima_rules, list) {
 412
 413                 if (!(entry->action & actmask))
 414                         continue;
 415
 416                 if (!ima_match_rules(entry, inode, cred, secid, func, mask))
 417                         continue;
 418
 419                 action |= entry->flags & IMA_ACTION_FLAGS;
 420
 421                 action |= entry->action & IMA_DO_MASK;
 422                 if (entry->action & IMA_APPRAISE) {
 423                         action |= get_subaction(entry, func);
 424                         action &= ~IMA_HASH;
 425                         if (ima_fail_unverifiable_sigs)
 426                                 action |= IMA_FAIL_UNVERIFIABLE_SIGS;
 427                 }
 428
 429                 if (entry->action & IMA_DO_MASK)
 430                         actmask &= ~(entry->action | entry->action << 1);
 431                 else
 432                         actmask &= ~(entry->action | entry->action >> 1);
 433
 434                 if ((pcr) && (entry->flags & IMA_PCR))
 435                         *pcr = entry->pcr;
 436
 437                 if (!actmask)
 438                         break;
 439         }
 440         rcu_read_unlock();
 441
 442         return action;
 443 }
 444
 445 /*
 446  * Initialize the ima_policy_flag variable based on the currently
 447  * loaded policy.  Based on this flag, the decision to short circuit
 448  * out of a function or not call the function in the first place
 449  * can be made earlier.
 450  */
 451 void ima_update_policy_flag(void)
 452 {
 453         struct ima_rule_entry *entry;
 454
 455         list_for_each_entry(entry, ima_rules, list) {
 456                 if (entry->action & IMA_DO_MASK)
 457                         ima_policy_flag |= entry->action;
 458         }
 459
 460         ima_appraise |= (build_ima_appraise | temp_ima_appraise);
 461         if (!ima_appraise)
 462                 ima_policy_flag &= ~IMA_APPRAISE;
 463 }
 464
 465 static int ima_appraise_flag(enum ima_hooks func)
 466 {
 467         if (func == MODULE_CHECK)
 468                 return IMA_APPRAISE_MODULES;
 469         else if (func == FIRMWARE_CHECK)
 470                 return IMA_APPRAISE_FIRMWARE;
 471         else if (func == POLICY_CHECK)
 472                 return IMA_APPRAISE_POLICY;
 473         else if (func == KEXEC_KERNEL_CHECK)
 474                 return IMA_APPRAISE_KEXEC;
 475         return 0;
 476 }
 477
 478 static void add_rules(struct ima_rule_entry *entries, int count,
 479                       enum policy_rule_list policy_rule)
 480 {
 481         int i = 0;
 482
 483         for (i = 0; i < count; i++) {
 484                 struct ima_rule_entry *entry;
 485
 486                 if (policy_rule & IMA_DEFAULT_POLICY)
 487                         list_add_tail(&entries[i].list, &ima_default_rules);
 488
 489                 if (policy_rule & IMA_CUSTOM_POLICY) {
 490                         entry = kmemdup(&entries[i], sizeof(*entry),
 491                                         GFP_KERNEL);
 492                         if (!entry)
 493                                 continue;
 494
 495                         list_add_tail(&entry->list, &ima_policy_rules);
 496                 }
 497                 if (entries[i].action == APPRAISE) {
 498                         temp_ima_appraise |= ima_appraise_flag(entries[i].func);
 499                         if (entries[i].func == POLICY_CHECK)
 500                                 temp_ima_appraise |= IMA_APPRAISE_POLICY;
 501                 }
 502         }
 503 }
 504
 505 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry);
 506
 507 static int __init ima_init_arch_policy(void)
 508 {
 509         const char * const *arch_rules;
 510         const char * const *rules;
 511         int arch_entries = 0;
 512         int i = 0;
 513
 514         arch_rules = arch_get_ima_policy();
 515         if (!arch_rules)
 516                 return arch_entries;
 517
 518         /* Get number of rules */
 519         for (rules = arch_rules; *rules != NULL; rules++)
 520                 arch_entries++;
 521
 522         arch_policy_entry = kcalloc(arch_entries + 1,
 523                                     sizeof(*arch_policy_entry), GFP_KERNEL);
 524         if (!arch_policy_entry)
 525                 return 0;
 526
 527         /* Convert each policy string rules to struct ima_rule_entry format */
 528         for (rules = arch_rules, i = 0; *rules != NULL; rules++) {
 529                 char rule[255];
 530                 int result;
 531
 532                 result = strlcpy(rule, *rules, sizeof(rule));
 533
 534                 INIT_LIST_HEAD(&arch_policy_entry[i].list);
 535                 result = ima_parse_rule(rule, &arch_policy_entry[i]);
 536                 if (result) {
 537                         pr_warn("Skipping unknown architecture policy rule: %s\n",
 538                                 rule);
 539                         memset(&arch_policy_entry[i], 0,
 540                                sizeof(*arch_policy_entry));
 541                         continue;
 542                 }
 543                 i++;
 544         }
 545         return i;
 546 }
 547
 548 /**
 549  * ima_init_policy - initialize the default measure rules.
 550  *
 551  * ima_rules points to either the ima_default_rules or the
 552  * the new ima_policy_rules.
 553  */
 554 void __init ima_init_policy(void)
 555 {
 556         int build_appraise_entries, arch_entries;
 557
 558         /* if !ima_policy, we load NO default rules */
 559         if (ima_policy)
 560                 add_rules(dont_measure_rules, ARRAY_SIZE(dont_measure_rules),
 561                           IMA_DEFAULT_POLICY);
 562
 563         switch (ima_policy) {
 564         case ORIGINAL_TCB:
 565                 add_rules(original_measurement_rules,
 566                           ARRAY_SIZE(original_measurement_rules),
 567                           IMA_DEFAULT_POLICY);
 568                 break;
 569         case DEFAULT_TCB:
 570                 add_rules(default_measurement_rules,
 571                           ARRAY_SIZE(default_measurement_rules),
 572                           IMA_DEFAULT_POLICY);
 573         default:
 574                 break;
 575         }
 576
 577         /*
 578          * Based on runtime secure boot flags, insert arch specific measurement
 579          * and appraise rules requiring file signatures for both the initial
 580          * and custom policies, prior to other appraise rules.
 581          * (Highest priority)
 582          */
 583         arch_entries = ima_init_arch_policy();
 584         if (!arch_entries)
 585                 pr_info("No architecture policies found\n");
 586         else
 587                 add_rules(arch_policy_entry, arch_entries,
 588                           IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY);
 589
 590         /*
 591          * Insert the builtin "secure_boot" policy rules requiring file
 592          * signatures, prior to other appraise rules.
 593          */
 594         if (ima_use_secure_boot)
 595                 add_rules(secure_boot_rules, ARRAY_SIZE(secure_boot_rules),
 596                           IMA_DEFAULT_POLICY);
 597
 598         /*
 599          * Insert the build time appraise rules requiring file signatures
 600          * for both the initial and custom policies, prior to other appraise
 601          * rules. As the secure boot rules includes all of the build time
 602          * rules, include either one or the other set of rules, but not both.
 603          */
 604         build_appraise_entries = ARRAY_SIZE(build_appraise_rules);
 605         if (build_appraise_entries) {
 606                 if (ima_use_secure_boot)
 607                         add_rules(build_appraise_rules, build_appraise_entries,
 608                                   IMA_CUSTOM_POLICY);
 609                 else
 610                         add_rules(build_appraise_rules, build_appraise_entries,
 611                                   IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY);
 612         }
 613
 614         if (ima_use_appraise_tcb)
 615                 add_rules(default_appraise_rules,
 616                           ARRAY_SIZE(default_appraise_rules),
 617                           IMA_DEFAULT_POLICY);
 618
 619         ima_rules = &ima_default_rules;
 620         ima_update_policy_flag();
 621 }
 622
 623 /* Make sure we have a valid policy, at least containing some rules. */
 624 int ima_check_policy(void)
 625 {
 626         if (list_empty(&ima_temp_rules))
 627                 return -EINVAL;
 628         return 0;
 629 }
 630
 631 /**
 632  * ima_update_policy - update default_rules with new measure rules
 633  *
 634  * Called on file .release to update the default rules with a complete new
 635  * policy.  What we do here is to splice ima_policy_rules and ima_temp_rules so
 636  * they make a queue.  The policy may be updated multiple times and this is the
 637  * RCU updater.
 638  *
 639  * Policy rules are never deleted so ima_policy_flag gets zeroed only once when
 640  * we switch from the default policy to user defined.
 641  */
 642 void ima_update_policy(void)
 643 {
 644         struct list_head *policy = &ima_policy_rules;
 645
 646         list_splice_tail_init_rcu(&ima_temp_rules, policy, synchronize_rcu);
 647
 648         if (ima_rules != policy) {
 649                 ima_policy_flag = 0;
 650                 ima_rules = policy;
 651
 652                 /*
 653                  * IMA architecture specific policy rules are specified
 654                  * as strings and converted to an array of ima_entry_rules
 655                  * on boot.  After loading a custom policy, free the
 656                  * architecture specific rules stored as an array.
 657                  */
 658                 kfree(arch_policy_entry);
 659         }
 660         ima_update_policy_flag();
 661 }
 662
 663 /* Keep the enumeration in sync with the policy_tokens! */
 664 enum {
 665         Opt_measure, Opt_dont_measure,
 666         Opt_appraise, Opt_dont_appraise,
 667         Opt_audit, Opt_hash, Opt_dont_hash,
 668         Opt_obj_user, Opt_obj_role, Opt_obj_type,
 669         Opt_subj_user, Opt_subj_role, Opt_subj_type,
 670         Opt_func, Opt_mask, Opt_fsmagic, Opt_fsname,
 671         Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq,
 672         Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt,
 673         Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
 674         Opt_appraise_type, Opt_permit_directio,
 675         Opt_pcr, Opt_err
 676 };
 677
 678 static const match_table_t policy_tokens = {
 679         {Opt_measure, "measure"},
 680         {Opt_dont_measure, "dont_measure"},
 681         {Opt_appraise, "appraise"},
 682         {Opt_dont_appraise, "dont_appraise"},
 683         {Opt_audit, "audit"},
 684         {Opt_hash, "hash"},
 685         {Opt_dont_hash, "dont_hash"},
 686         {Opt_obj_user, "obj_user=%s"},
 687         {Opt_obj_role, "obj_role=%s"},
 688         {Opt_obj_type, "obj_type=%s"},
 689         {Opt_subj_user, "subj_user=%s"},
 690         {Opt_subj_role, "subj_role=%s"},
 691         {Opt_subj_type, "subj_type=%s"},
 692         {Opt_func, "func=%s"},
 693         {Opt_mask, "mask=%s"},
 694         {Opt_fsmagic, "fsmagic=%s"},
 695         {Opt_fsname, "fsname=%s"},
 696         {Opt_fsuuid, "fsuuid=%s"},
 697         {Opt_uid_eq, "uid=%s"},
 698         {Opt_euid_eq, "euid=%s"},
 699         {Opt_fowner_eq, "fowner=%s"},
 700         {Opt_uid_gt, "uid>%s"},
 701         {Opt_euid_gt, "euid>%s"},
 702         {Opt_fowner_gt, "fowner>%s"},
 703         {Opt_uid_lt, "uid<%s"},
 704         {Opt_euid_lt, "euid<%s"},
 705         {Opt_fowner_lt, "fowner<%s"},
 706         {Opt_appraise_type, "appraise_type=%s"},
 707         {Opt_permit_directio, "permit_directio"},
 708         {Opt_pcr, "pcr=%s"},
 709         {Opt_err, NULL}
 710 };
 711
 712 static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 713                              substring_t *args, int lsm_rule, int audit_type)
 714 {
 715         int result;
 716
 717         if (entry->lsm[lsm_rule].rule)
 718                 return -EINVAL;
 719
 720         entry->lsm[lsm_rule].args_p = match_strdup(args);
 721         if (!entry->lsm[lsm_rule].args_p)
 722                 return -ENOMEM;
 723
 724         entry->lsm[lsm_rule].type = audit_type;
 725         result = security_filter_rule_init(entry->lsm[lsm_rule].type,
 726                                            Audit_equal,
 727                                            entry->lsm[lsm_rule].args_p,
 728                                            &entry->lsm[lsm_rule].rule);
 729         if (!entry->lsm[lsm_rule].rule) {
 730                 kfree(entry->lsm[lsm_rule].args_p);
 731                 return -EINVAL;
 732         }
 733
 734         return result;
 735 }
 736
 737 static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
 738                               bool (*rule_operator)(kuid_t, kuid_t))
 739 {
 740         if (!ab)
 741                 return;
 742
 743         if (rule_operator == &uid_gt)
 744                 audit_log_format(ab, "%s>", key);
 745         else if (rule_operator == &uid_lt)
 746                 audit_log_format(ab, "%s<", key);
 747         else
 748                 audit_log_format(ab, "%s=", key);
 749         audit_log_format(ab, "%s ", value);
 750 }
 751 static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
 752 {
 753         ima_log_string_op(ab, key, value, NULL);
 754 }
 755
 756 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
 757 {
 758         struct audit_buffer *ab;
 759         char *from;
 760         char *p;
 761         bool uid_token;
 762         int result = 0;
 763
 764         ab = integrity_audit_log_start(audit_context(), GFP_KERNEL,
 765                                        AUDIT_INTEGRITY_POLICY_RULE);
 766
 767         entry->uid = INVALID_UID;
 768         entry->fowner = INVALID_UID;
 769         entry->uid_op = &uid_eq;
 770         entry->fowner_op = &uid_eq;
 771         entry->action = UNKNOWN;
 772         while ((p = strsep(&rule, " \t")) != NULL) {
 773                 substring_t args[MAX_OPT_ARGS];
 774                 int token;
 775                 unsigned long lnum;
 776
 777                 if (result < 0)
 778                         break;
 779                 if ((*p == '\0') || (*p == ' ') || (*p == '\t'))
 780                         continue;
 781                 token = match_token(p, policy_tokens, args);
 782                 switch (token) {
 783                 case Opt_measure:
 784                         ima_log_string(ab, "action", "measure");
 785
 786                         if (entry->action != UNKNOWN)
 787                                 result = -EINVAL;
 788
 789                         entry->action = MEASURE;
 790                         break;
 791                 case Opt_dont_measure:
 792                         ima_log_string(ab, "action", "dont_measure");
 793
 794                         if (entry->action != UNKNOWN)
 795                                 result = -EINVAL;
 796
 797                         entry->action = DONT_MEASURE;
 798                         break;
 799                 case Opt_appraise:
 800                         ima_log_string(ab, "action", "appraise");
 801
 802                         if (entry->action != UNKNOWN)
 803                                 result = -EINVAL;
 804
 805                         entry->action = APPRAISE;
 806                         break;
 807                 case Opt_dont_appraise:
 808                         ima_log_string(ab, "action", "dont_appraise");
 809
 810                         if (entry->action != UNKNOWN)
 811                                 result = -EINVAL;
 812
 813                         entry->action = DONT_APPRAISE;
 814                         break;
 815                 case Opt_audit:
 816                         ima_log_string(ab, "action", "audit");
 817
 818                         if (entry->action != UNKNOWN)
 819                                 result = -EINVAL;
 820
 821                         entry->action = AUDIT;
 822                         break;
 823                 case Opt_hash:
 824                         ima_log_string(ab, "action", "hash");
 825
 826                         if (entry->action != UNKNOWN)
 827                                 result = -EINVAL;
 828
 829                         entry->action = HASH;
 830                         break;
 831                 case Opt_dont_hash:
 832                         ima_log_string(ab, "action", "dont_hash");
 833
 834                         if (entry->action != UNKNOWN)
 835                                 result = -EINVAL;
 836
 837                         entry->action = DONT_HASH;
 838                         break;
 839                 case Opt_func:
 840                         ima_log_string(ab, "func", args[0].from);
 841
 842                         if (entry->func)
 843                                 result = -EINVAL;
 844
 845                         if (strcmp(args[0].from, "FILE_CHECK") == 0)
 846                                 entry->func = FILE_CHECK;
 847                         /* PATH_CHECK is for backwards compat */
 848                         else if (strcmp(args[0].from, "PATH_CHECK") == 0)
 849                                 entry->func = FILE_CHECK;
 850                         else if (strcmp(args[0].from, "MODULE_CHECK") == 0)
 851                                 entry->func = MODULE_CHECK;
 852                         else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0)
 853                                 entry->func = FIRMWARE_CHECK;
 854                         else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
 855                                 || (strcmp(args[0].from, "MMAP_CHECK") == 0))
 856                                 entry->func = MMAP_CHECK;
 857                         else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
 858                                 entry->func = BPRM_CHECK;
 859                         else if (strcmp(args[0].from, "CREDS_CHECK") == 0)
 860                                 entry->func = CREDS_CHECK;
 861                         else if (strcmp(args[0].from, "KEXEC_KERNEL_CHECK") ==
 862                                  0)
 863                                 entry->func = KEXEC_KERNEL_CHECK;
 864                         else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK")
 865                                  == 0)
 866                                 entry->func = KEXEC_INITRAMFS_CHECK;
 867                         else if (strcmp(args[0].from, "POLICY_CHECK") == 0)
 868                                 entry->func = POLICY_CHECK;
 869                         else
 870                                 result = -EINVAL;
 871                         if (!result)
 872                                 entry->flags |= IMA_FUNC;
 873                         break;
 874                 case Opt_mask:
 875                         ima_log_string(ab, "mask", args[0].from);
 876
 877                         if (entry->mask)
 878                                 result = -EINVAL;
 879
 880                         from = args[0].from;
 881                         if (*from == '^')
 882                                 from++;
 883
 884                         if ((strcmp(from, "MAY_EXEC")) == 0)
 885                                 entry->mask = MAY_EXEC;
 886                         else if (strcmp(from, "MAY_WRITE") == 0)
 887                                 entry->mask = MAY_WRITE;
 888                         else if (strcmp(from, "MAY_READ") == 0)
 889                                 entry->mask = MAY_READ;
 890                         else if (strcmp(from, "MAY_APPEND") == 0)
 891                                 entry->mask = MAY_APPEND;
 892                         else
 893                                 result = -EINVAL;
 894                         if (!result)
 895                                 entry->flags |= (*args[0].from == '^')
 896                                      ? IMA_INMASK : IMA_MASK;
 897                         break;
 898                 case Opt_fsmagic:
 899                         ima_log_string(ab, "fsmagic", args[0].from);
 900
 901                         if (entry->fsmagic) {
 902                                 result = -EINVAL;
 903                                 break;
 904                         }
 905
 906                         result = kstrtoul(args[0].from, 16, &entry->fsmagic);
 907                         if (!result)
 908                                 entry->flags |= IMA_FSMAGIC;
 909                         break;
 910                 case Opt_fsname:
 911                         ima_log_string(ab, "fsname", args[0].from);
 912
 913                         entry->fsname = kstrdup(args[0].from, GFP_KERNEL);
 914                         if (!entry->fsname) {
 915                                 result = -ENOMEM;
 916                                 break;
 917                         }
 918                         result = 0;
 919                         entry->flags |= IMA_FSNAME;
 920                         break;
 921                 case Opt_fsuuid:
 922                         ima_log_string(ab, "fsuuid", args[0].from);
 923
 924                         if (!uuid_is_null(&entry->fsuuid)) {
 925                                 result = -EINVAL;
 926                                 break;
 927                         }
 928
 929                         result = uuid_parse(args[0].from, &entry->fsuuid);
 930                         if (!result)
 931                                 entry->flags |= IMA_FSUUID;
 932                         break;
 933                 case Opt_uid_gt:
 934                 case Opt_euid_gt:
 935                         entry->uid_op = &uid_gt;
 936                         /* fall through */
 937                 case Opt_uid_lt:
 938                 case Opt_euid_lt:
 939                         if ((token == Opt_uid_lt) || (token == Opt_euid_lt))
 940                                 entry->uid_op = &uid_lt;
 941                         /* fall through */
 942                 case Opt_uid_eq:
 943                 case Opt_euid_eq:
 944                         uid_token = (token == Opt_uid_eq) ||
 945                                     (token == Opt_uid_gt) ||
 946                                     (token == Opt_uid_lt);
 947
 948                         ima_log_string_op(ab, uid_token ? "uid" : "euid",
 949                                           args[0].from, entry->uid_op);
 950
 951                         if (uid_valid(entry->uid)) {
 952                                 result = -EINVAL;
 953                                 break;
 954                         }
 955
 956                         result = kstrtoul(args[0].from, 10, &lnum);
 957                         if (!result) {
 958                                 entry->uid = make_kuid(current_user_ns(),
 959                                                        (uid_t) lnum);
 960                                 if (!uid_valid(entry->uid) ||
 961                                     (uid_t)lnum != lnum)
 962                                         result = -EINVAL;
 963                                 else
 964                                         entry->flags |= uid_token
 965                                             ? IMA_UID : IMA_EUID;
 966                         }
 967                         break;
 968                 case Opt_fowner_gt:
 969                         entry->fowner_op = &uid_gt;
 970                         /* fall through */
 971                 case Opt_fowner_lt:
 972                         if (token == Opt_fowner_lt)
 973                                 entry->fowner_op = &uid_lt;
 974                         /* fall through */
 975                 case Opt_fowner_eq:
 976                         ima_log_string_op(ab, "fowner", args[0].from,
 977                                           entry->fowner_op);
 978
 979                         if (uid_valid(entry->fowner)) {
 980                                 result = -EINVAL;
 981                                 break;
 982                         }
 983
 984                         result = kstrtoul(args[0].from, 10, &lnum);
 985                         if (!result) {
 986                                 entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
 987                                 if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
 988                                         result = -EINVAL;
 989                                 else
 990                                         entry->flags |= IMA_FOWNER;
 991                         }
 992                         break;
 993                 case Opt_obj_user:
 994                         ima_log_string(ab, "obj_user", args[0].from);
 995                         result = ima_lsm_rule_init(entry, args,
 996                                                    LSM_OBJ_USER,
 997                                                    AUDIT_OBJ_USER);
 998                         break;
 999                 case Opt_obj_role:
1000                         ima_log_string(ab, "obj_role", args[0].from);
1001                         result = ima_lsm_rule_init(entry, args,
1002                                                    LSM_OBJ_ROLE,
1003                                                    AUDIT_OBJ_ROLE);
1004                         break;
1005                 case Opt_obj_type:
1006                         ima_log_string(ab, "obj_type", args[0].from);
1007                         result = ima_lsm_rule_init(entry, args,
1008                                                    LSM_OBJ_TYPE,
1009                                                    AUDIT_OBJ_TYPE);
1010                         break;
1011                 case Opt_subj_user:
1012                         ima_log_string(ab, "subj_user", args[0].from);
1013                         result = ima_lsm_rule_init(entry, args,
1014                                                    LSM_SUBJ_USER,
1015                                                    AUDIT_SUBJ_USER);
1016                         break;
1017                 case Opt_subj_role:
1018                         ima_log_string(ab, "subj_role", args[0].from);
1019                         result = ima_lsm_rule_init(entry, args,
1020                                                    LSM_SUBJ_ROLE,
1021                                                    AUDIT_SUBJ_ROLE);
1022                         break;
1023                 case Opt_subj_type:
1024                         ima_log_string(ab, "subj_type", args[0].from);
1025                         result = ima_lsm_rule_init(entry, args,
1026                                                    LSM_SUBJ_TYPE,
1027                                                    AUDIT_SUBJ_TYPE);
1028                         break;
1029                 case Opt_appraise_type:
1030                         if (entry->action != APPRAISE) {
1031                                 result = -EINVAL;
1032                                 break;
1033                         }
1034
1035                         ima_log_string(ab, "appraise_type", args[0].from);
1036                         if ((strcmp(args[0].from, "imasig")) == 0)
1037                                 entry->flags |= IMA_DIGSIG_REQUIRED;
1038                         else
1039                                 result = -EINVAL;
1040                         break;
1041                 case Opt_permit_directio:
1042                         entry->flags |= IMA_PERMIT_DIRECTIO;
1043                         break;
1044                 case Opt_pcr:
1045                         if (entry->action != MEASURE) {
1046                                 result = -EINVAL;
1047                                 break;
1048                         }
1049                         ima_log_string(ab, "pcr", args[0].from);
1050
1051                         result = kstrtoint(args[0].from, 10, &entry->pcr);
1052                         if (result || INVALID_PCR(entry->pcr))
1053                                 result = -EINVAL;
1054                         else
1055                                 entry->flags |= IMA_PCR;
1056
1057                         break;
1058                 case Opt_err:
1059                         ima_log_string(ab, "UNKNOWN", p);
1060                         result = -EINVAL;
1061                         break;
1062                 }
1063         }
1064         if (!result && (entry->action == UNKNOWN))
1065                 result = -EINVAL;
1066         else if (entry->action == APPRAISE)
1067                 temp_ima_appraise |= ima_appraise_flag(entry->func);
1068
1069         audit_log_format(ab, "res=%d", !result);
1070         audit_log_end(ab);
1071         return result;
1072 }
1073
1074 /**
1075  * ima_parse_add_rule - add a rule to ima_policy_rules
1076  * @rule - ima measurement policy rule
1077  *
1078  * Avoid locking by allowing just one writer at a time in ima_write_policy()
1079  * Returns the length of the rule parsed, an error code on failure
1080  */
1081 ssize_t ima_parse_add_rule(char *rule)
1082 {
1083         static const char op[] = "update_policy";
1084         char *p;
1085         struct ima_rule_entry *entry;
1086         ssize_t result, len;
1087         int audit_info = 0;
1088
1089         p = strsep(&rule, "\n");
1090         len = strlen(p) + 1;
1091         p += strspn(p, " \t");
1092
1093         if (*p == '#' || *p == '\0')
1094                 return len;
1095
1096         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1097         if (!entry) {
1098                 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
1099                                     NULL, op, "-ENOMEM", -ENOMEM, audit_info);
1100                 return -ENOMEM;
1101         }
1102
1103         INIT_LIST_HEAD(&entry->list);
1104
1105         result = ima_parse_rule(p, entry);
1106         if (result) {
1107                 kfree(entry);
1108                 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
1109                                     NULL, op, "invalid-policy", result,
1110                                     audit_info);
1111                 return result;
1112         }
1113
1114         list_add_tail(&entry->list, &ima_temp_rules);
1115
1116         return len;
1117 }
1118
1119 /**
1120  * ima_delete_rules() called to cleanup invalid in-flight policy.
1121  * We don't need locking as we operate on the temp list, which is
1122  * different from the active one.  There is also only one user of
1123  * ima_delete_rules() at a time.
1124  */
1125 void ima_delete_rules(void)
1126 {
1127         struct ima_rule_entry *entry, *tmp;
1128         int i;
1129
1130         temp_ima_appraise = 0;
1131         list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) {
1132                 for (i = 0; i < MAX_LSM_RULES; i++)
1133                         kfree(entry->lsm[i].args_p);
1134
1135                 list_del(&entry->list);
1136                 kfree(entry);
1137         }
1138 }
1139
1140 #ifdef  CONFIG_IMA_READ_POLICY
1141 enum {
1142         mask_exec = 0, mask_write, mask_read, mask_append
1143 };
1144
1145 static const char *const mask_tokens[] = {
1146         "^MAY_EXEC",
1147         "^MAY_WRITE",
1148         "^MAY_READ",
1149         "^MAY_APPEND"
1150 };
1151
1152 #define __ima_hook_stringify(str)       (#str),
1153
1154 static const char *const func_tokens[] = {
1155         __ima_hooks(__ima_hook_stringify)
1156 };
1157
1158 void *ima_policy_start(struct seq_file *m, loff_t *pos)
1159 {
1160         loff_t l = *pos;
1161         struct ima_rule_entry *entry;
1162
1163         rcu_read_lock();
1164         list_for_each_entry_rcu(entry, ima_rules, list) {
1165                 if (!l--) {
1166                         rcu_read_unlock();
1167                         return entry;
1168                 }
1169         }
1170         rcu_read_unlock();
1171         return NULL;
1172 }
1173
1174 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos)
1175 {
1176         struct ima_rule_entry *entry = v;
1177
1178         rcu_read_lock();
1179         entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list);
1180         rcu_read_unlock();
1181         (*pos)++;
1182
1183         return (&entry->list == ima_rules) ? NULL : entry;
1184 }
1185
1186 void ima_policy_stop(struct seq_file *m, void *v)
1187 {
1188 }
1189
1190 #define pt(token)       policy_tokens[token].pattern
1191 #define mt(token)       mask_tokens[token]
1192
1193 /*
1194  * policy_func_show - display the ima_hooks policy rule
1195  */
1196 static void policy_func_show(struct seq_file *m, enum ima_hooks func)
1197 {
1198         if (func > 0 && func < MAX_CHECK)
1199                 seq_printf(m, "func=%s ", func_tokens[func]);
1200         else
1201                 seq_printf(m, "func=%d ", func);
1202 }
1203
1204 int ima_policy_show(struct seq_file *m, void *v)
1205 {
1206         struct ima_rule_entry *entry = v;
1207         int i;
1208         char tbuf[64] = {0,};
1209         int offset = 0;
1210
1211         rcu_read_lock();
1212
1213         if (entry->action & MEASURE)
1214                 seq_puts(m, pt(Opt_measure));
1215         if (entry->action & DONT_MEASURE)
1216                 seq_puts(m, pt(Opt_dont_measure));
1217         if (entry->action & APPRAISE)
1218                 seq_puts(m, pt(Opt_appraise));
1219         if (entry->action & DONT_APPRAISE)
1220                 seq_puts(m, pt(Opt_dont_appraise));
1221         if (entry->action & AUDIT)
1222                 seq_puts(m, pt(Opt_audit));
1223         if (entry->action & HASH)
1224                 seq_puts(m, pt(Opt_hash));
1225         if (entry->action & DONT_HASH)
1226                 seq_puts(m, pt(Opt_dont_hash));
1227
1228         seq_puts(m, " ");
1229
1230         if (entry->flags & IMA_FUNC)
1231                 policy_func_show(m, entry->func);
1232
1233         if ((entry->flags & IMA_MASK) || (entry->flags & IMA_INMASK)) {
1234                 if (entry->flags & IMA_MASK)
1235                         offset = 1;
1236                 if (entry->mask & MAY_EXEC)
1237                         seq_printf(m, pt(Opt_mask), mt(mask_exec) + offset);
1238                 if (entry->mask & MAY_WRITE)
1239                         seq_printf(m, pt(Opt_mask), mt(mask_write) + offset);
1240                 if (entry->mask & MAY_READ)
1241                         seq_printf(m, pt(Opt_mask), mt(mask_read) + offset);
1242                 if (entry->mask & MAY_APPEND)
1243                         seq_printf(m, pt(Opt_mask), mt(mask_append) + offset);
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 */