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
  10 #include <linux/init.h>
  11 #include <linux/list.h>
  12 #include <linux/kernel_read_file.h>
  13 #include <linux/fs.h>
  14 #include <linux/security.h>
  15 #include <linux/magic.h>
  16 #include <linux/parser.h>
  17 #include <linux/slab.h>
  18 #include <linux/rculist.h>
  19 #include <linux/genhd.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/ima.h>
  22
  23 #include "ima.h"
  24
  25 /* flags definitions */
  26 #define IMA_FUNC        0x0001
  27 #define IMA_MASK        0x0002
  28 #define IMA_FSMAGIC     0x0004
  29 #define IMA_UID         0x0008
  30 #define IMA_FOWNER      0x0010
  31 #define IMA_FSUUID      0x0020
  32 #define IMA_INMASK      0x0040
  33 #define IMA_EUID        0x0080
  34 #define IMA_PCR         0x0100
  35 #define IMA_FSNAME      0x0200
  36 #define IMA_KEYRINGS    0x0400
  37 #define IMA_LABEL       0x0800
  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) >= (sizeof_field(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_opt_list {
  65         size_t count;
  66         char *items[];
  67 };
  68
  69 struct ima_rule_entry {
  70         struct list_head list;
  71         int action;
  72         unsigned int flags;
  73         enum ima_hooks func;
  74         int mask;
  75         unsigned long fsmagic;
  76         uuid_t fsuuid;
  77         kuid_t uid;
  78         kuid_t fowner;
  79         bool (*uid_op)(kuid_t, kuid_t);    /* Handlers for operators       */
  80         bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
  81         int pcr;
  82         struct {
  83                 void *rule;     /* LSM file metadata specific */
  84                 char *args_p;   /* audit value */
  85                 int type;       /* audit type */
  86         } lsm[MAX_LSM_RULES];
  87         char *fsname;
  88         struct ima_rule_opt_list *keyrings; /* Measure keys added to these keyrings */
  89         struct ima_rule_opt_list *label; /* Measure data grouped under this label */
  90         struct ima_template_desc *template;
  91 };
  92
  93 /*
  94  * Without LSM specific knowledge, the default policy can only be
  95  * written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
  96  */
  97
  98 /*
  99  * The minimum rule set to allow for full TCB coverage.  Measures all files
 100  * opened or mmap for exec and everything read by root.  Dangerous because
 101  * normal users can easily run the machine out of memory simply building
 102  * and running executables.
 103  */
 104 static struct ima_rule_entry dont_measure_rules[] __ro_after_init = {
 105         {.action = DONT_MEASURE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 106         {.action = DONT_MEASURE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
 107         {.action = DONT_MEASURE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
 108         {.action = DONT_MEASURE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
 109         {.action = DONT_MEASURE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 110         {.action = DONT_MEASURE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
 111         {.action = DONT_MEASURE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
 112         {.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
 113         {.action = DONT_MEASURE, .fsmagic = SMACK_MAGIC, .flags = IMA_FSMAGIC},
 114         {.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC,
 115          .flags = IMA_FSMAGIC},
 116         {.action = DONT_MEASURE, .fsmagic = CGROUP2_SUPER_MAGIC,
 117          .flags = IMA_FSMAGIC},
 118         {.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
 119         {.action = DONT_MEASURE, .fsmagic = EFIVARFS_MAGIC, .flags = IMA_FSMAGIC}
 120 };
 121
 122 static struct ima_rule_entry original_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_MASK | IMA_UID},
 130         {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
 131         {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
 132 };
 133
 134 static struct ima_rule_entry default_measurement_rules[] __ro_after_init = {
 135         {.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
 136          .flags = IMA_FUNC | IMA_MASK},
 137         {.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
 138          .flags = IMA_FUNC | IMA_MASK},
 139         {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
 140          .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq,
 141          .flags = IMA_FUNC | IMA_INMASK | IMA_EUID},
 142         {.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
 143          .uid = GLOBAL_ROOT_UID, .uid_op = &uid_eq,
 144          .flags = IMA_FUNC | IMA_INMASK | IMA_UID},
 145         {.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
 146         {.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
 147         {.action = MEASURE, .func = POLICY_CHECK, .flags = IMA_FUNC},
 148 };
 149
 150 static struct ima_rule_entry default_appraise_rules[] __ro_after_init = {
 151         {.action = DONT_APPRAISE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 152         {.action = DONT_APPRAISE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
 153         {.action = DONT_APPRAISE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
 154         {.action = DONT_APPRAISE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
 155         {.action = DONT_APPRAISE, .fsmagic = RAMFS_MAGIC, .flags = IMA_FSMAGIC},
 156         {.action = DONT_APPRAISE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 157         {.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
 158         {.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
 159         {.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
 160         {.action = DONT_APPRAISE, .fsmagic = SMACK_MAGIC, .flags = IMA_FSMAGIC},
 161         {.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
 162         {.action = DONT_APPRAISE, .fsmagic = EFIVARFS_MAGIC, .flags = IMA_FSMAGIC},
 163         {.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 164         {.action = DONT_APPRAISE, .fsmagic = CGROUP2_SUPER_MAGIC, .flags = IMA_FSMAGIC},
 165 #ifdef CONFIG_IMA_WRITE_POLICY
 166         {.action = APPRAISE, .func = POLICY_CHECK,
 167         .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 168 #endif
 169 #ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT
 170         {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .fowner_op = &uid_eq,
 171          .flags = IMA_FOWNER},
 172 #else
 173         /* force signature */
 174         {.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .fowner_op = &uid_eq,
 175          .flags = IMA_FOWNER | IMA_DIGSIG_REQUIRED},
 176 #endif
 177 };
 178
 179 static struct ima_rule_entry build_appraise_rules[] __ro_after_init = {
 180 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_MODULE_SIGS
 181         {.action = APPRAISE, .func = MODULE_CHECK,
 182          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 183 #endif
 184 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_FIRMWARE_SIGS
 185         {.action = APPRAISE, .func = FIRMWARE_CHECK,
 186          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 187 #endif
 188 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_KEXEC_SIGS
 189         {.action = APPRAISE, .func = KEXEC_KERNEL_CHECK,
 190          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 191 #endif
 192 #ifdef CONFIG_IMA_APPRAISE_REQUIRE_POLICY_SIGS
 193         {.action = APPRAISE, .func = POLICY_CHECK,
 194          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 195 #endif
 196 };
 197
 198 static struct ima_rule_entry secure_boot_rules[] __ro_after_init = {
 199         {.action = APPRAISE, .func = MODULE_CHECK,
 200          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 201         {.action = APPRAISE, .func = FIRMWARE_CHECK,
 202          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 203         {.action = APPRAISE, .func = KEXEC_KERNEL_CHECK,
 204          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 205         {.action = APPRAISE, .func = POLICY_CHECK,
 206          .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
 207 };
 208
 209 static struct ima_rule_entry critical_data_rules[] __ro_after_init = {
 210         {.action = MEASURE, .func = CRITICAL_DATA, .flags = IMA_FUNC},
 211 };
 212
 213 /* An array of architecture specific rules */
 214 static struct ima_rule_entry *arch_policy_entry __ro_after_init;
 215
 216 static LIST_HEAD(ima_default_rules);
 217 static LIST_HEAD(ima_policy_rules);
 218 static LIST_HEAD(ima_temp_rules);
 219 static struct list_head *ima_rules = &ima_default_rules;
 220
 221 static int ima_policy __initdata;
 222
 223 static int __init default_measure_policy_setup(char *str)
 224 {
 225         if (ima_policy)
 226                 return 1;
 227
 228         ima_policy = ORIGINAL_TCB;
 229         return 1;
 230 }
 231 __setup("ima_tcb", default_measure_policy_setup);
 232
 233 static bool ima_use_appraise_tcb __initdata;
 234 static bool ima_use_secure_boot __initdata;
 235 static bool ima_use_critical_data __initdata;
 236 static bool ima_fail_unverifiable_sigs __ro_after_init;
 237 static int __init policy_setup(char *str)
 238 {
 239         char *p;
 240
 241         while ((p = strsep(&str, " |\n")) != NULL) {
 242                 if (*p == ' ')
 243                         continue;
 244                 if ((strcmp(p, "tcb") == 0) && !ima_policy)
 245                         ima_policy = DEFAULT_TCB;
 246                 else if (strcmp(p, "appraise_tcb") == 0)
 247                         ima_use_appraise_tcb = true;
 248                 else if (strcmp(p, "secure_boot") == 0)
 249                         ima_use_secure_boot = true;
 250                 else if (strcmp(p, "critical_data") == 0)
 251                         ima_use_critical_data = true;
 252                 else if (strcmp(p, "fail_securely") == 0)
 253                         ima_fail_unverifiable_sigs = true;
 254                 else
 255                         pr_err("policy \"%s\" not found", p);
 256         }
 257
 258         return 1;
 259 }
 260 __setup("ima_policy=", policy_setup);
 261
 262 static int __init default_appraise_policy_setup(char *str)
 263 {
 264         ima_use_appraise_tcb = true;
 265         return 1;
 266 }
 267 __setup("ima_appraise_tcb", default_appraise_policy_setup);
 268
 269 static struct ima_rule_opt_list *ima_alloc_rule_opt_list(const substring_t *src)
 270 {
 271         struct ima_rule_opt_list *opt_list;
 272         size_t count = 0;
 273         char *src_copy;
 274         char *cur, *next;
 275         size_t i;
 276
 277         src_copy = match_strdup(src);
 278         if (!src_copy)
 279                 return ERR_PTR(-ENOMEM);
 280
 281         next = src_copy;
 282         while ((cur = strsep(&next, "|"))) {
 283                 /* Don't accept an empty list item */
 284                 if (!(*cur)) {
 285                         kfree(src_copy);
 286                         return ERR_PTR(-EINVAL);
 287                 }
 288                 count++;
 289         }
 290
 291         /* Don't accept an empty list */
 292         if (!count) {
 293                 kfree(src_copy);
 294                 return ERR_PTR(-EINVAL);
 295         }
 296
 297         opt_list = kzalloc(struct_size(opt_list, items, count), GFP_KERNEL);
 298         if (!opt_list) {
 299                 kfree(src_copy);
 300                 return ERR_PTR(-ENOMEM);
 301         }
 302
 303         /*
 304          * strsep() has already replaced all instances of '|' with '\0',
 305          * leaving a byte sequence of NUL-terminated strings. Reference each
 306          * string with the array of items.
 307          *
 308          * IMPORTANT: Ownership of the allocated buffer is transferred from
 309          * src_copy to the first element in the items array. To free the
 310          * buffer, kfree() must only be called on the first element of the
 311          * array.
 312          */
 313         for (i = 0, cur = src_copy; i < count; i++) {
 314                 opt_list->items[i] = cur;
 315                 cur = strchr(cur, '\0') + 1;
 316         }
 317         opt_list->count = count;
 318
 319         return opt_list;
 320 }
 321
 322 static void ima_free_rule_opt_list(struct ima_rule_opt_list *opt_list)
 323 {
 324         if (!opt_list)
 325                 return;
 326
 327         if (opt_list->count) {
 328                 kfree(opt_list->items[0]);
 329                 opt_list->count = 0;
 330         }
 331
 332         kfree(opt_list);
 333 }
 334
 335 static void ima_lsm_free_rule(struct ima_rule_entry *entry)
 336 {
 337         int i;
 338
 339         for (i = 0; i < MAX_LSM_RULES; i++) {
 340                 ima_filter_rule_free(entry->lsm[i].rule);
 341                 kfree(entry->lsm[i].args_p);
 342         }
 343 }
 344
 345 static void ima_free_rule(struct ima_rule_entry *entry)
 346 {
 347         if (!entry)
 348                 return;
 349
 350         /*
 351          * entry->template->fields may be allocated in ima_parse_rule() but that
 352          * reference is owned by the corresponding ima_template_desc element in
 353          * the defined_templates list and cannot be freed here
 354          */
 355         kfree(entry->fsname);
 356         ima_free_rule_opt_list(entry->keyrings);
 357         ima_lsm_free_rule(entry);
 358         kfree(entry);
 359 }
 360
 361 static struct ima_rule_entry *ima_lsm_copy_rule(struct ima_rule_entry *entry)
 362 {
 363         struct ima_rule_entry *nentry;
 364         int i;
 365
 366         /*
 367          * Immutable elements are copied over as pointers and data; only
 368          * lsm rules can change
 369          */
 370         nentry = kmemdup(entry, sizeof(*nentry), GFP_KERNEL);
 371         if (!nentry)
 372                 return NULL;
 373
 374         memset(nentry->lsm, 0, sizeof_field(struct ima_rule_entry, lsm));
 375
 376         for (i = 0; i < MAX_LSM_RULES; i++) {
 377                 if (!entry->lsm[i].args_p)
 378                         continue;
 379
 380                 nentry->lsm[i].type = entry->lsm[i].type;
 381                 nentry->lsm[i].args_p = entry->lsm[i].args_p;
 382                 /*
 383                  * Remove the reference from entry so that the associated
 384                  * memory will not be freed during a later call to
 385                  * ima_lsm_free_rule(entry).
 386                  */
 387                 entry->lsm[i].args_p = NULL;
 388
 389                 ima_filter_rule_init(nentry->lsm[i].type, Audit_equal,
 390                                      nentry->lsm[i].args_p,
 391                                      &nentry->lsm[i].rule);
 392                 if (!nentry->lsm[i].rule)
 393                         pr_warn("rule for LSM \'%s\' is undefined\n",
 394                                 nentry->lsm[i].args_p);
 395         }
 396         return nentry;
 397 }
 398
 399 static int ima_lsm_update_rule(struct ima_rule_entry *entry)
 400 {
 401         struct ima_rule_entry *nentry;
 402
 403         nentry = ima_lsm_copy_rule(entry);
 404         if (!nentry)
 405                 return -ENOMEM;
 406
 407         list_replace_rcu(&entry->list, &nentry->list);
 408         synchronize_rcu();
 409         /*
 410          * ima_lsm_copy_rule() shallow copied all references, except for the
 411          * LSM references, from entry to nentry so we only want to free the LSM
 412          * references and the entry itself. All other memory refrences will now
 413          * be owned by nentry.
 414          */
 415         ima_lsm_free_rule(entry);
 416         kfree(entry);
 417
 418         return 0;
 419 }
 420
 421 static bool ima_rule_contains_lsm_cond(struct ima_rule_entry *entry)
 422 {
 423         int i;
 424
 425         for (i = 0; i < MAX_LSM_RULES; i++)
 426                 if (entry->lsm[i].args_p)
 427                         return true;
 428
 429         return false;
 430 }
 431
 432 /*
 433  * The LSM policy can be reloaded, leaving the IMA LSM based rules referring
 434  * to the old, stale LSM policy.  Update the IMA LSM based rules to reflect
 435  * the reloaded LSM policy.
 436  */
 437 static void ima_lsm_update_rules(void)
 438 {
 439         struct ima_rule_entry *entry, *e;
 440         int result;
 441
 442         list_for_each_entry_safe(entry, e, &ima_policy_rules, list) {
 443                 if (!ima_rule_contains_lsm_cond(entry))
 444                         continue;
 445
 446                 result = ima_lsm_update_rule(entry);
 447                 if (result) {
 448                         pr_err("lsm rule update error %d\n", result);
 449                         return;
 450                 }
 451         }
 452 }
 453
 454 int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
 455                           void *lsm_data)
 456 {
 457         if (event != LSM_POLICY_CHANGE)
 458                 return NOTIFY_DONE;
 459
 460         ima_lsm_update_rules();
 461         return NOTIFY_OK;
 462 }
 463
 464 /**
 465  * ima_match_rule_data - determine whether func_data matches the policy rule
 466  * @rule: a pointer to a rule
 467  * @func_data: data to match against the measure rule data
 468  * @cred: a pointer to a credentials structure for user validation
 469  *
 470  * Returns true if func_data matches one in the rule, false otherwise.
 471  */
 472 static bool ima_match_rule_data(struct ima_rule_entry *rule,
 473                                 const char *func_data,
 474                                 const struct cred *cred)
 475 {
 476         const struct ima_rule_opt_list *opt_list = NULL;
 477         bool matched = false;
 478         size_t i;
 479
 480         if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
 481                 return false;
 482
 483         switch (rule->func) {
 484         case KEY_CHECK:
 485                 if (!rule->keyrings)
 486                         return true;
 487
 488                 opt_list = rule->keyrings;
 489                 break;
 490         case CRITICAL_DATA:
 491                 if (!rule->label)
 492                         return true;
 493
 494                 opt_list = rule->label;
 495                 break;
 496         default:
 497                 return false;
 498         }
 499
 500         if (!func_data)
 501                 return false;
 502
 503         for (i = 0; i < opt_list->count; i++) {
 504                 if (!strcmp(opt_list->items[i], func_data)) {
 505                         matched = true;
 506                         break;
 507                 }
 508         }
 509
 510         return matched;
 511 }
 512
 513 /**
 514  * ima_match_rules - determine whether an inode matches the policy rule.
 515  * @rule: a pointer to a rule
 516  * @inode: a pointer to an inode
 517  * @cred: a pointer to a credentials structure for user validation
 518  * @secid: the secid of the task to be validated
 519  * @func: LIM hook identifier
 520  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
 521  * @func_data: func specific data, may be NULL
 522  *
 523  * Returns true on rule match, false on failure.
 524  */
 525 static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
 526                             const struct cred *cred, u32 secid,
 527                             enum ima_hooks func, int mask,
 528                             const char *func_data)
 529 {
 530         int i;
 531
 532         if ((rule->flags & IMA_FUNC) &&
 533             (rule->func != func && func != POST_SETATTR))
 534                 return false;
 535
 536         switch (func) {
 537         case KEY_CHECK:
 538         case CRITICAL_DATA:
 539                 return ((rule->func == func) &&
 540                         ima_match_rule_data(rule, func_data, cred));
 541         default:
 542                 break;
 543         }
 544
 545         if ((rule->flags & IMA_MASK) &&
 546             (rule->mask != mask && func != POST_SETATTR))
 547                 return false;
 548         if ((rule->flags & IMA_INMASK) &&
 549             (!(rule->mask & mask) && func != POST_SETATTR))
 550                 return false;
 551         if ((rule->flags & IMA_FSMAGIC)
 552             && rule->fsmagic != inode->i_sb->s_magic)
 553                 return false;
 554         if ((rule->flags & IMA_FSNAME)
 555             && strcmp(rule->fsname, inode->i_sb->s_type->name))
 556                 return false;
 557         if ((rule->flags & IMA_FSUUID) &&
 558             !uuid_equal(&rule->fsuuid, &inode->i_sb->s_uuid))
 559                 return false;
 560         if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
 561                 return false;
 562         if (rule->flags & IMA_EUID) {
 563                 if (has_capability_noaudit(current, CAP_SETUID)) {
 564                         if (!rule->uid_op(cred->euid, rule->uid)
 565                             && !rule->uid_op(cred->suid, rule->uid)
 566                             && !rule->uid_op(cred->uid, rule->uid))
 567                                 return false;
 568                 } else if (!rule->uid_op(cred->euid, rule->uid))
 569                         return false;
 570         }
 571
 572         if ((rule->flags & IMA_FOWNER) &&
 573             !rule->fowner_op(inode->i_uid, rule->fowner))
 574                 return false;
 575         for (i = 0; i < MAX_LSM_RULES; i++) {
 576                 int rc = 0;
 577                 u32 osid;
 578
 579                 if (!rule->lsm[i].rule) {
 580                         if (!rule->lsm[i].args_p)
 581                                 continue;
 582                         else
 583                                 return false;
 584                 }
 585                 switch (i) {
 586                 case LSM_OBJ_USER:
 587                 case LSM_OBJ_ROLE:
 588                 case LSM_OBJ_TYPE:
 589                         security_inode_getsecid(inode, &osid);
 590                         rc = ima_filter_rule_match(osid, rule->lsm[i].type,
 591                                                    Audit_equal,
 592                                                    rule->lsm[i].rule);
 593                         break;
 594                 case LSM_SUBJ_USER:
 595                 case LSM_SUBJ_ROLE:
 596                 case LSM_SUBJ_TYPE:
 597                         rc = ima_filter_rule_match(secid, rule->lsm[i].type,
 598                                                    Audit_equal,
 599                                                    rule->lsm[i].rule);
 600                 default:
 601                         break;
 602                 }
 603                 if (!rc)
 604                         return false;
 605         }
 606         return true;
 607 }
 608
 609 /*
 610  * In addition to knowing that we need to appraise the file in general,
 611  * we need to differentiate between calling hooks, for hook specific rules.
 612  */
 613 static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
 614 {
 615         if (!(rule->flags & IMA_FUNC))
 616                 return IMA_FILE_APPRAISE;
 617
 618         switch (func) {
 619         case MMAP_CHECK:
 620                 return IMA_MMAP_APPRAISE;
 621         case BPRM_CHECK:
 622                 return IMA_BPRM_APPRAISE;
 623         case CREDS_CHECK:
 624                 return IMA_CREDS_APPRAISE;
 625         case FILE_CHECK:
 626         case POST_SETATTR:
 627                 return IMA_FILE_APPRAISE;
 628         case MODULE_CHECK ... MAX_CHECK - 1:
 629         default:
 630                 return IMA_READ_APPRAISE;
 631         }
 632 }
 633
 634 /**
 635  * ima_match_policy - decision based on LSM and other conditions
 636  * @inode: pointer to an inode for which the policy decision is being made
 637  * @cred: pointer to a credentials structure for which the policy decision is
 638  *        being made
 639  * @secid: LSM secid of the task to be validated
 640  * @func: IMA hook identifier
 641  * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
 642  * @pcr: set the pcr to extend
 643  * @template_desc: the template that should be used for this rule
 644  * @func_data: func specific data, may be NULL
 645  *
 646  * Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
 647  * conditions.
 648  *
 649  * Since the IMA policy may be updated multiple times we need to lock the
 650  * list when walking it.  Reads are many orders of magnitude more numerous
 651  * than writes so ima_match_policy() is classical RCU candidate.
 652  */
 653 int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
 654                      enum ima_hooks func, int mask, int flags, int *pcr,
 655                      struct ima_template_desc **template_desc,
 656                      const char *func_data)
 657 {
 658         struct ima_rule_entry *entry;
 659         int action = 0, actmask = flags | (flags << 1);
 660
 661         if (template_desc && !*template_desc)
 662                 *template_desc = ima_template_desc_current();
 663
 664         rcu_read_lock();
 665         list_for_each_entry_rcu(entry, ima_rules, list) {
 666
 667                 if (!(entry->action & actmask))
 668                         continue;
 669
 670                 if (!ima_match_rules(entry, inode, cred, secid, func, mask,
 671                                      func_data))
 672                         continue;
 673
 674                 action |= entry->flags & IMA_ACTION_FLAGS;
 675
 676                 action |= entry->action & IMA_DO_MASK;
 677                 if (entry->action & IMA_APPRAISE) {
 678                         action |= get_subaction(entry, func);
 679                         action &= ~IMA_HASH;
 680                         if (ima_fail_unverifiable_sigs)
 681                                 action |= IMA_FAIL_UNVERIFIABLE_SIGS;
 682                 }
 683
 684
 685                 if (entry->action & IMA_DO_MASK)
 686                         actmask &= ~(entry->action | entry->action << 1);
 687                 else
 688                         actmask &= ~(entry->action | entry->action >> 1);
 689
 690                 if ((pcr) && (entry->flags & IMA_PCR))
 691                         *pcr = entry->pcr;
 692
 693                 if (template_desc && entry->template)
 694                         *template_desc = entry->template;
 695
 696                 if (!actmask)
 697                         break;
 698         }
 699         rcu_read_unlock();
 700
 701         return action;
 702 }
 703
 704 /*
 705  * Initialize the ima_policy_flag variable based on the currently
 706  * loaded policy.  Based on this flag, the decision to short circuit
 707  * out of a function or not call the function in the first place
 708  * can be made earlier.
 709  */
 710 void ima_update_policy_flag(void)
 711 {
 712         struct ima_rule_entry *entry;
 713
 714         list_for_each_entry(entry, ima_rules, list) {
 715                 if (entry->action & IMA_DO_MASK)
 716                         ima_policy_flag |= entry->action;
 717         }
 718
 719         ima_appraise |= (build_ima_appraise | temp_ima_appraise);
 720         if (!ima_appraise)
 721                 ima_policy_flag &= ~IMA_APPRAISE;
 722 }
 723
 724 static int ima_appraise_flag(enum ima_hooks func)
 725 {
 726         if (func == MODULE_CHECK)
 727                 return IMA_APPRAISE_MODULES;
 728         else if (func == FIRMWARE_CHECK)
 729                 return IMA_APPRAISE_FIRMWARE;
 730         else if (func == POLICY_CHECK)
 731                 return IMA_APPRAISE_POLICY;
 732         else if (func == KEXEC_KERNEL_CHECK)
 733                 return IMA_APPRAISE_KEXEC;
 734         return 0;
 735 }
 736
 737 static void add_rules(struct ima_rule_entry *entries, int count,
 738                       enum policy_rule_list policy_rule)
 739 {
 740         int i = 0;
 741
 742         for (i = 0; i < count; i++) {
 743                 struct ima_rule_entry *entry;
 744
 745                 if (policy_rule & IMA_DEFAULT_POLICY)
 746                         list_add_tail(&entries[i].list, &ima_default_rules);
 747
 748                 if (policy_rule & IMA_CUSTOM_POLICY) {
 749                         entry = kmemdup(&entries[i], sizeof(*entry),
 750                                         GFP_KERNEL);
 751                         if (!entry)
 752                                 continue;
 753
 754                         list_add_tail(&entry->list, &ima_policy_rules);
 755                 }
 756                 if (entries[i].action == APPRAISE) {
 757                         if (entries != build_appraise_rules)
 758                                 temp_ima_appraise |=
 759                                         ima_appraise_flag(entries[i].func);
 760                         else
 761                                 build_ima_appraise |=
 762                                         ima_appraise_flag(entries[i].func);
 763                 }
 764         }
 765 }
 766
 767 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry);
 768
 769 static int __init ima_init_arch_policy(void)
 770 {
 771         const char * const *arch_rules;
 772         const char * const *rules;
 773         int arch_entries = 0;
 774         int i = 0;
 775
 776         arch_rules = arch_get_ima_policy();
 777         if (!arch_rules)
 778                 return arch_entries;
 779
 780         /* Get number of rules */
 781         for (rules = arch_rules; *rules != NULL; rules++)
 782                 arch_entries++;
 783
 784         arch_policy_entry = kcalloc(arch_entries + 1,
 785                                     sizeof(*arch_policy_entry), GFP_KERNEL);
 786         if (!arch_policy_entry)
 787                 return 0;
 788
 789         /* Convert each policy string rules to struct ima_rule_entry format */
 790         for (rules = arch_rules, i = 0; *rules != NULL; rules++) {
 791                 char rule[255];
 792                 int result;
 793
 794                 result = strlcpy(rule, *rules, sizeof(rule));
 795
 796                 INIT_LIST_HEAD(&arch_policy_entry[i].list);
 797                 result = ima_parse_rule(rule, &arch_policy_entry[i]);
 798                 if (result) {
 799                         pr_warn("Skipping unknown architecture policy rule: %s\n",
 800                                 rule);
 801                         memset(&arch_policy_entry[i], 0,
 802                                sizeof(*arch_policy_entry));
 803                         continue;
 804                 }
 805                 i++;
 806         }
 807         return i;
 808 }
 809
 810 /**
 811  * ima_init_policy - initialize the default measure rules.
 812  *
 813  * ima_rules points to either the ima_default_rules or the
 814  * the new ima_policy_rules.
 815  */
 816 void __init ima_init_policy(void)
 817 {
 818         int build_appraise_entries, arch_entries;
 819
 820         /* if !ima_policy, we load NO default rules */
 821         if (ima_policy)
 822                 add_rules(dont_measure_rules, ARRAY_SIZE(dont_measure_rules),
 823                           IMA_DEFAULT_POLICY);
 824
 825         switch (ima_policy) {
 826         case ORIGINAL_TCB:
 827                 add_rules(original_measurement_rules,
 828                           ARRAY_SIZE(original_measurement_rules),
 829                           IMA_DEFAULT_POLICY);
 830                 break;
 831         case DEFAULT_TCB:
 832                 add_rules(default_measurement_rules,
 833                           ARRAY_SIZE(default_measurement_rules),
 834                           IMA_DEFAULT_POLICY);
 835         default:
 836                 break;
 837         }
 838
 839         /*
 840          * Based on runtime secure boot flags, insert arch specific measurement
 841          * and appraise rules requiring file signatures for both the initial
 842          * and custom policies, prior to other appraise rules.
 843          * (Highest priority)
 844          */
 845         arch_entries = ima_init_arch_policy();
 846         if (!arch_entries)
 847                 pr_info("No architecture policies found\n");
 848         else
 849                 add_rules(arch_policy_entry, arch_entries,
 850                           IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY);
 851
 852         /*
 853          * Insert the builtin "secure_boot" policy rules requiring file
 854          * signatures, prior to other appraise rules.
 855          */
 856         if (ima_use_secure_boot)
 857                 add_rules(secure_boot_rules, ARRAY_SIZE(secure_boot_rules),
 858                           IMA_DEFAULT_POLICY);
 859
 860         /*
 861          * Insert the build time appraise rules requiring file signatures
 862          * for both the initial and custom policies, prior to other appraise
 863          * rules. As the secure boot rules includes all of the build time
 864          * rules, include either one or the other set of rules, but not both.
 865          */
 866         build_appraise_entries = ARRAY_SIZE(build_appraise_rules);
 867         if (build_appraise_entries) {
 868                 if (ima_use_secure_boot)
 869                         add_rules(build_appraise_rules, build_appraise_entries,
 870                                   IMA_CUSTOM_POLICY);
 871                 else
 872                         add_rules(build_appraise_rules, build_appraise_entries,
 873                                   IMA_DEFAULT_POLICY | IMA_CUSTOM_POLICY);
 874         }
 875
 876         if (ima_use_appraise_tcb)
 877                 add_rules(default_appraise_rules,
 878                           ARRAY_SIZE(default_appraise_rules),
 879                           IMA_DEFAULT_POLICY);
 880
 881         if (ima_use_critical_data)
 882                 add_rules(critical_data_rules,
 883                           ARRAY_SIZE(critical_data_rules),
 884                           IMA_DEFAULT_POLICY);
 885
 886         ima_update_policy_flag();
 887 }
 888
 889 /* Make sure we have a valid policy, at least containing some rules. */
 890 int ima_check_policy(void)
 891 {
 892         if (list_empty(&ima_temp_rules))
 893                 return -EINVAL;
 894         return 0;
 895 }
 896
 897 /**
 898  * ima_update_policy - update default_rules with new measure rules
 899  *
 900  * Called on file .release to update the default rules with a complete new
 901  * policy.  What we do here is to splice ima_policy_rules and ima_temp_rules so
 902  * they make a queue.  The policy may be updated multiple times and this is the
 903  * RCU updater.
 904  *
 905  * Policy rules are never deleted so ima_policy_flag gets zeroed only once when
 906  * we switch from the default policy to user defined.
 907  */
 908 void ima_update_policy(void)
 909 {
 910         struct list_head *policy = &ima_policy_rules;
 911
 912         list_splice_tail_init_rcu(&ima_temp_rules, policy, synchronize_rcu);
 913
 914         if (ima_rules != policy) {
 915                 ima_policy_flag = 0;
 916                 ima_rules = policy;
 917
 918                 /*
 919                  * IMA architecture specific policy rules are specified
 920                  * as strings and converted to an array of ima_entry_rules
 921                  * on boot.  After loading a custom policy, free the
 922                  * architecture specific rules stored as an array.
 923                  */
 924                 kfree(arch_policy_entry);
 925         }
 926         ima_update_policy_flag();
 927
 928         /* Custom IMA policy has been loaded */
 929         ima_process_queued_keys();
 930 }
 931
 932 /* Keep the enumeration in sync with the policy_tokens! */
 933 enum {
 934         Opt_measure, Opt_dont_measure,
 935         Opt_appraise, Opt_dont_appraise,
 936         Opt_audit, Opt_hash, Opt_dont_hash,
 937         Opt_obj_user, Opt_obj_role, Opt_obj_type,
 938         Opt_subj_user, Opt_subj_role, Opt_subj_type,
 939         Opt_func, Opt_mask, Opt_fsmagic, Opt_fsname,
 940         Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq,
 941         Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt,
 942         Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
 943         Opt_appraise_type, Opt_appraise_flag,
 944         Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
 945         Opt_label, Opt_err
 946 };
 947
 948 static const match_table_t policy_tokens = {
 949         {Opt_measure, "measure"},
 950         {Opt_dont_measure, "dont_measure"},
 951         {Opt_appraise, "appraise"},
 952         {Opt_dont_appraise, "dont_appraise"},
 953         {Opt_audit, "audit"},
 954         {Opt_hash, "hash"},
 955         {Opt_dont_hash, "dont_hash"},
 956         {Opt_obj_user, "obj_user=%s"},
 957         {Opt_obj_role, "obj_role=%s"},
 958         {Opt_obj_type, "obj_type=%s"},
 959         {Opt_subj_user, "subj_user=%s"},
 960         {Opt_subj_role, "subj_role=%s"},
 961         {Opt_subj_type, "subj_type=%s"},
 962         {Opt_func, "func=%s"},
 963         {Opt_mask, "mask=%s"},
 964         {Opt_fsmagic, "fsmagic=%s"},
 965         {Opt_fsname, "fsname=%s"},
 966         {Opt_fsuuid, "fsuuid=%s"},
 967         {Opt_uid_eq, "uid=%s"},
 968         {Opt_euid_eq, "euid=%s"},
 969         {Opt_fowner_eq, "fowner=%s"},
 970         {Opt_uid_gt, "uid>%s"},
 971         {Opt_euid_gt, "euid>%s"},
 972         {Opt_fowner_gt, "fowner>%s"},
 973         {Opt_uid_lt, "uid<%s"},
 974         {Opt_euid_lt, "euid<%s"},
 975         {Opt_fowner_lt, "fowner<%s"},
 976         {Opt_appraise_type, "appraise_type=%s"},
 977         {Opt_appraise_flag, "appraise_flag=%s"},
 978         {Opt_permit_directio, "permit_directio"},
 979         {Opt_pcr, "pcr=%s"},
 980         {Opt_template, "template=%s"},
 981         {Opt_keyrings, "keyrings=%s"},
 982         {Opt_label, "label=%s"},
 983         {Opt_err, NULL}
 984 };
 985
 986 static int ima_lsm_rule_init(struct ima_rule_entry *entry,
 987                              substring_t *args, int lsm_rule, int audit_type)
 988 {
 989         int result;
 990
 991         if (entry->lsm[lsm_rule].rule)
 992                 return -EINVAL;
 993
 994         entry->lsm[lsm_rule].args_p = match_strdup(args);
 995         if (!entry->lsm[lsm_rule].args_p)
 996                 return -ENOMEM;
 997
 998         entry->lsm[lsm_rule].type = audit_type;
 999         result = ima_filter_rule_init(entry->lsm[lsm_rule].type, Audit_equal,
1000                                       entry->lsm[lsm_rule].args_p,
1001                                       &entry->lsm[lsm_rule].rule);
1002         if (!entry->lsm[lsm_rule].rule) {
1003                 pr_warn("rule for LSM \'%s\' is undefined\n",
1004                         entry->lsm[lsm_rule].args_p);
1005
1006                 if (ima_rules == &ima_default_rules) {
1007                         kfree(entry->lsm[lsm_rule].args_p);
1008                         entry->lsm[lsm_rule].args_p = NULL;
1009                         result = -EINVAL;
1010                 } else
1011                         result = 0;
1012         }
1013
1014         return result;
1015 }
1016
1017 static void ima_log_string_op(struct audit_buffer *ab, char *key, char *value,
1018                               bool (*rule_operator)(kuid_t, kuid_t))
1019 {
1020         if (!ab)
1021                 return;
1022
1023         if (rule_operator == &uid_gt)
1024                 audit_log_format(ab, "%s>", key);
1025         else if (rule_operator == &uid_lt)
1026                 audit_log_format(ab, "%s<", key);
1027         else
1028                 audit_log_format(ab, "%s=", key);
1029         audit_log_format(ab, "%s ", value);
1030 }
1031 static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
1032 {
1033         ima_log_string_op(ab, key, value, NULL);
1034 }
1035
1036 /*
1037  * Validating the appended signature included in the measurement list requires
1038  * the file hash calculated without the appended signature (i.e., the 'd-modsig'
1039  * field). Therefore, notify the user if they have the 'modsig' field but not
1040  * the 'd-modsig' field in the template.
1041  */
1042 static void check_template_modsig(const struct ima_template_desc *template)
1043 {
1044 #define MSG "template with 'modsig' field also needs 'd-modsig' field\n"
1045         bool has_modsig, has_dmodsig;
1046         static bool checked;
1047         int i;
1048
1049         /* We only need to notify the user once. */
1050         if (checked)
1051                 return;
1052
1053         has_modsig = has_dmodsig = false;
1054         for (i = 0; i < template->num_fields; i++) {
1055                 if (!strcmp(template->fields[i]->field_id, "modsig"))
1056                         has_modsig = true;
1057                 else if (!strcmp(template->fields[i]->field_id, "d-modsig"))
1058                         has_dmodsig = true;
1059         }
1060
1061         if (has_modsig && !has_dmodsig)
1062                 pr_notice(MSG);
1063
1064         checked = true;
1065 #undef MSG
1066 }
1067
1068 static bool ima_validate_rule(struct ima_rule_entry *entry)
1069 {
1070         /* Ensure that the action is set and is compatible with the flags */
1071         if (entry->action == UNKNOWN)
1072                 return false;
1073
1074         if (entry->action != MEASURE && entry->flags & IMA_PCR)
1075                 return false;
1076
1077         if (entry->action != APPRAISE &&
1078             entry->flags & (IMA_DIGSIG_REQUIRED | IMA_MODSIG_ALLOWED | IMA_CHECK_BLACKLIST))
1079                 return false;
1080
1081         /*
1082          * The IMA_FUNC bit must be set if and only if there's a valid hook
1083          * function specified, and vice versa. Enforcing this property allows
1084          * for the NONE case below to validate a rule without an explicit hook
1085          * function.
1086          */
1087         if (((entry->flags & IMA_FUNC) && entry->func == NONE) ||
1088             (!(entry->flags & IMA_FUNC) && entry->func != NONE))
1089                 return false;
1090
1091         /*
1092          * Ensure that the hook function is compatible with the other
1093          * components of the rule
1094          */
1095         switch (entry->func) {
1096         case NONE:
1097         case FILE_CHECK:
1098         case MMAP_CHECK:
1099         case BPRM_CHECK:
1100         case CREDS_CHECK:
1101         case POST_SETATTR:
1102         case FIRMWARE_CHECK:
1103         case POLICY_CHECK:
1104                 if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC |
1105                                      IMA_UID | IMA_FOWNER | IMA_FSUUID |
1106                                      IMA_INMASK | IMA_EUID | IMA_PCR |
1107                                      IMA_FSNAME | IMA_DIGSIG_REQUIRED |
1108                                      IMA_PERMIT_DIRECTIO))
1109                         return false;
1110
1111                 break;
1112         case MODULE_CHECK:
1113         case KEXEC_KERNEL_CHECK:
1114         case KEXEC_INITRAMFS_CHECK:
1115                 if (entry->flags & ~(IMA_FUNC | IMA_MASK | IMA_FSMAGIC |
1116                                      IMA_UID | IMA_FOWNER | IMA_FSUUID |
1117                                      IMA_INMASK | IMA_EUID | IMA_PCR |
1118                                      IMA_FSNAME | IMA_DIGSIG_REQUIRED |
1119                                      IMA_PERMIT_DIRECTIO | IMA_MODSIG_ALLOWED |
1120                                      IMA_CHECK_BLACKLIST))
1121                         return false;
1122
1123                 break;
1124         case KEXEC_CMDLINE:
1125                 if (entry->action & ~(MEASURE | DONT_MEASURE))
1126                         return false;
1127
1128                 if (entry->flags & ~(IMA_FUNC | IMA_FSMAGIC | IMA_UID |
1129                                      IMA_FOWNER | IMA_FSUUID | IMA_EUID |
1130                                      IMA_PCR | IMA_FSNAME))
1131                         return false;
1132
1133                 break;
1134         case KEY_CHECK:
1135                 if (entry->action & ~(MEASURE | DONT_MEASURE))
1136                         return false;
1137
1138                 if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR |
1139                                      IMA_KEYRINGS))
1140                         return false;
1141
1142                 if (ima_rule_contains_lsm_cond(entry))
1143                         return false;
1144
1145                 break;
1146         case CRITICAL_DATA:
1147                 if (entry->action & ~(MEASURE | DONT_MEASURE))
1148                         return false;
1149
1150                 if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR |
1151                                      IMA_LABEL))
1152                         return false;
1153
1154                 if (ima_rule_contains_lsm_cond(entry))
1155                         return false;
1156
1157                 break;
1158         default:
1159                 return false;
1160         }
1161
1162         /* Ensure that combinations of flags are compatible with each other */
1163         if (entry->flags & IMA_CHECK_BLACKLIST &&
1164             !(entry->flags & IMA_MODSIG_ALLOWED))
1165                 return false;
1166
1167         return true;
1168 }
1169
1170 static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
1171 {
1172         struct audit_buffer *ab;
1173         char *from;
1174         char *p;
1175         bool uid_token;
1176         struct ima_template_desc *template_desc;
1177         int result = 0;
1178
1179         ab = integrity_audit_log_start(audit_context(), GFP_KERNEL,
1180                                        AUDIT_INTEGRITY_POLICY_RULE);
1181
1182         entry->uid = INVALID_UID;
1183         entry->fowner = INVALID_UID;
1184         entry->uid_op = &uid_eq;
1185         entry->fowner_op = &uid_eq;
1186         entry->action = UNKNOWN;
1187         while ((p = strsep(&rule, " \t")) != NULL) {
1188                 substring_t args[MAX_OPT_ARGS];
1189                 int token;
1190                 unsigned long lnum;
1191
1192                 if (result < 0)
1193                         break;
1194                 if ((*p == '\0') || (*p == ' ') || (*p == '\t'))
1195                         continue;
1196                 token = match_token(p, policy_tokens, args);
1197                 switch (token) {
1198                 case Opt_measure:
1199                         ima_log_string(ab, "action", "measure");
1200
1201                         if (entry->action != UNKNOWN)
1202                                 result = -EINVAL;
1203
1204                         entry->action = MEASURE;
1205                         break;
1206                 case Opt_dont_measure:
1207                         ima_log_string(ab, "action", "dont_measure");
1208
1209                         if (entry->action != UNKNOWN)
1210                                 result = -EINVAL;
1211
1212                         entry->action = DONT_MEASURE;
1213                         break;
1214                 case Opt_appraise:
1215                         ima_log_string(ab, "action", "appraise");
1216
1217                         if (entry->action != UNKNOWN)
1218                                 result = -EINVAL;
1219
1220                         entry->action = APPRAISE;
1221                         break;
1222                 case Opt_dont_appraise:
1223                         ima_log_string(ab, "action", "dont_appraise");
1224
1225                         if (entry->action != UNKNOWN)
1226                                 result = -EINVAL;
1227
1228                         entry->action = DONT_APPRAISE;
1229                         break;
1230                 case Opt_audit:
1231                         ima_log_string(ab, "action", "audit");
1232
1233                         if (entry->action != UNKNOWN)
1234                                 result = -EINVAL;
1235
1236                         entry->action = AUDIT;
1237                         break;
1238                 case Opt_hash:
1239                         ima_log_string(ab, "action", "hash");
1240
1241                         if (entry->action != UNKNOWN)
1242                                 result = -EINVAL;
1243
1244                         entry->action = HASH;
1245                         break;
1246                 case Opt_dont_hash:
1247                         ima_log_string(ab, "action", "dont_hash");
1248
1249                         if (entry->action != UNKNOWN)
1250                                 result = -EINVAL;
1251
1252                         entry->action = DONT_HASH;
1253                         break;
1254                 case Opt_func:
1255                         ima_log_string(ab, "func", args[0].from);
1256
1257                         if (entry->func)
1258                                 result = -EINVAL;
1259
1260                         if (strcmp(args[0].from, "FILE_CHECK") == 0)
1261                                 entry->func = FILE_CHECK;
1262                         /* PATH_CHECK is for backwards compat */
1263                         else if (strcmp(args[0].from, "PATH_CHECK") == 0)
1264                                 entry->func = FILE_CHECK;
1265                         else if (strcmp(args[0].from, "MODULE_CHECK") == 0)
1266                                 entry->func = MODULE_CHECK;
1267                         else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0)
1268                                 entry->func = FIRMWARE_CHECK;
1269                         else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
1270                                 || (strcmp(args[0].from, "MMAP_CHECK") == 0))
1271                                 entry->func = MMAP_CHECK;
1272                         else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
1273                                 entry->func = BPRM_CHECK;
1274                         else if (strcmp(args[0].from, "CREDS_CHECK") == 0)
1275                                 entry->func = CREDS_CHECK;
1276                         else if (strcmp(args[0].from, "KEXEC_KERNEL_CHECK") ==
1277                                  0)
1278                                 entry->func = KEXEC_KERNEL_CHECK;
1279                         else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK")
1280                                  == 0)
1281                                 entry->func = KEXEC_INITRAMFS_CHECK;
1282                         else if (strcmp(args[0].from, "POLICY_CHECK") == 0)
1283                                 entry->func = POLICY_CHECK;
1284                         else if (strcmp(args[0].from, "KEXEC_CMDLINE") == 0)
1285                                 entry->func = KEXEC_CMDLINE;
1286                         else if (IS_ENABLED(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) &&
1287                                  strcmp(args[0].from, "KEY_CHECK") == 0)
1288                                 entry->func = KEY_CHECK;
1289                         else if (strcmp(args[0].from, "CRITICAL_DATA") == 0)
1290                                 entry->func = CRITICAL_DATA;
1291                         else
1292                                 result = -EINVAL;
1293                         if (!result)
1294                                 entry->flags |= IMA_FUNC;
1295                         break;
1296                 case Opt_mask:
1297                         ima_log_string(ab, "mask", args[0].from);
1298
1299                         if (entry->mask)
1300                                 result = -EINVAL;
1301
1302                         from = args[0].from;
1303                         if (*from == '^')
1304                                 from++;
1305
1306                         if ((strcmp(from, "MAY_EXEC")) == 0)
1307                                 entry->mask = MAY_EXEC;
1308                         else if (strcmp(from, "MAY_WRITE") == 0)
1309                                 entry->mask = MAY_WRITE;
1310                         else if (strcmp(from, "MAY_READ") == 0)
1311                                 entry->mask = MAY_READ;
1312                         else if (strcmp(from, "MAY_APPEND") == 0)
1313                                 entry->mask = MAY_APPEND;
1314                         else
1315                                 result = -EINVAL;
1316                         if (!result)
1317                                 entry->flags |= (*args[0].from == '^')
1318                                      ? IMA_INMASK : IMA_MASK;
1319                         break;
1320                 case Opt_fsmagic:
1321                         ima_log_string(ab, "fsmagic", args[0].from);
1322
1323                         if (entry->fsmagic) {
1324                                 result = -EINVAL;
1325                                 break;
1326                         }
1327
1328                         result = kstrtoul(args[0].from, 16, &entry->fsmagic);
1329                         if (!result)
1330                                 entry->flags |= IMA_FSMAGIC;
1331                         break;
1332                 case Opt_fsname:
1333                         ima_log_string(ab, "fsname", args[0].from);
1334
1335                         entry->fsname = kstrdup(args[0].from, GFP_KERNEL);
1336                         if (!entry->fsname) {
1337                                 result = -ENOMEM;
1338                                 break;
1339                         }
1340                         result = 0;
1341                         entry->flags |= IMA_FSNAME;
1342                         break;
1343                 case Opt_keyrings:
1344                         ima_log_string(ab, "keyrings", args[0].from);
1345
1346                         if (!IS_ENABLED(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) ||
1347                             entry->keyrings) {
1348                                 result = -EINVAL;
1349                                 break;
1350                         }
1351
1352                         entry->keyrings = ima_alloc_rule_opt_list(args);
1353                         if (IS_ERR(entry->keyrings)) {
1354                                 result = PTR_ERR(entry->keyrings);
1355                                 entry->keyrings = NULL;
1356                                 break;
1357                         }
1358
1359                         entry->flags |= IMA_KEYRINGS;
1360                         break;
1361                 case Opt_label:
1362                         ima_log_string(ab, "label", args[0].from);
1363
1364                         if (entry->label) {
1365                                 result = -EINVAL;
1366                                 break;
1367                         }
1368
1369                         entry->label = ima_alloc_rule_opt_list(args);
1370                         if (IS_ERR(entry->label)) {
1371                                 result = PTR_ERR(entry->label);
1372                                 entry->label = NULL;
1373                                 break;
1374                         }
1375
1376                         entry->flags |= IMA_LABEL;
1377                         break;
1378                 case Opt_fsuuid:
1379                         ima_log_string(ab, "fsuuid", args[0].from);
1380
1381                         if (!uuid_is_null(&entry->fsuuid)) {
1382                                 result = -EINVAL;
1383                                 break;
1384                         }
1385
1386                         result = uuid_parse(args[0].from, &entry->fsuuid);
1387                         if (!result)
1388                                 entry->flags |= IMA_FSUUID;
1389                         break;
1390                 case Opt_uid_gt:
1391                 case Opt_euid_gt:
1392                         entry->uid_op = &uid_gt;
1393                         fallthrough;
1394                 case Opt_uid_lt:
1395                 case Opt_euid_lt:
1396                         if ((token == Opt_uid_lt) || (token == Opt_euid_lt))
1397                                 entry->uid_op = &uid_lt;
1398                         fallthrough;
1399                 case Opt_uid_eq:
1400                 case Opt_euid_eq:
1401                         uid_token = (token == Opt_uid_eq) ||
1402                                     (token == Opt_uid_gt) ||
1403                                     (token == Opt_uid_lt);
1404
1405                         ima_log_string_op(ab, uid_token ? "uid" : "euid",
1406                                           args[0].from, entry->uid_op);
1407
1408                         if (uid_valid(entry->uid)) {
1409                                 result = -EINVAL;
1410                                 break;
1411                         }
1412
1413                         result = kstrtoul(args[0].from, 10, &lnum);
1414                         if (!result) {
1415                                 entry->uid = make_kuid(current_user_ns(),
1416                                                        (uid_t) lnum);
1417                                 if (!uid_valid(entry->uid) ||
1418                                     (uid_t)lnum != lnum)
1419                                         result = -EINVAL;
1420                                 else
1421                                         entry->flags |= uid_token
1422                                             ? IMA_UID : IMA_EUID;
1423                         }
1424                         break;
1425                 case Opt_fowner_gt:
1426                         entry->fowner_op = &uid_gt;
1427                         fallthrough;
1428                 case Opt_fowner_lt:
1429                         if (token == Opt_fowner_lt)
1430                                 entry->fowner_op = &uid_lt;
1431                         fallthrough;
1432                 case Opt_fowner_eq:
1433                         ima_log_string_op(ab, "fowner", args[0].from,
1434                                           entry->fowner_op);
1435
1436                         if (uid_valid(entry->fowner)) {
1437                                 result = -EINVAL;
1438                                 break;
1439                         }
1440
1441                         result = kstrtoul(args[0].from, 10, &lnum);
1442                         if (!result) {
1443                                 entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
1444                                 if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
1445                                         result = -EINVAL;
1446                                 else
1447                                         entry->flags |= IMA_FOWNER;
1448                         }
1449                         break;
1450                 case Opt_obj_user:
1451                         ima_log_string(ab, "obj_user", args[0].from);
1452                         result = ima_lsm_rule_init(entry, args,
1453                                                    LSM_OBJ_USER,
1454                                                    AUDIT_OBJ_USER);
1455                         break;
1456                 case Opt_obj_role:
1457                         ima_log_string(ab, "obj_role", args[0].from);
1458                         result = ima_lsm_rule_init(entry, args,
1459                                                    LSM_OBJ_ROLE,
1460                                                    AUDIT_OBJ_ROLE);
1461                         break;
1462                 case Opt_obj_type:
1463                         ima_log_string(ab, "obj_type", args[0].from);
1464                         result = ima_lsm_rule_init(entry, args,
1465                                                    LSM_OBJ_TYPE,
1466                                                    AUDIT_OBJ_TYPE);
1467                         break;
1468                 case Opt_subj_user:
1469                         ima_log_string(ab, "subj_user", args[0].from);
1470                         result = ima_lsm_rule_init(entry, args,
1471                                                    LSM_SUBJ_USER,
1472                                                    AUDIT_SUBJ_USER);
1473                         break;
1474                 case Opt_subj_role:
1475                         ima_log_string(ab, "subj_role", args[0].from);
1476                         result = ima_lsm_rule_init(entry, args,
1477                                                    LSM_SUBJ_ROLE,
1478                                                    AUDIT_SUBJ_ROLE);
1479                         break;
1480                 case Opt_subj_type:
1481                         ima_log_string(ab, "subj_type", args[0].from);
1482                         result = ima_lsm_rule_init(entry, args,
1483                                                    LSM_SUBJ_TYPE,
1484                                                    AUDIT_SUBJ_TYPE);
1485                         break;
1486                 case Opt_appraise_type:
1487                         ima_log_string(ab, "appraise_type", args[0].from);
1488                         if ((strcmp(args[0].from, "imasig")) == 0)
1489                                 entry->flags |= IMA_DIGSIG_REQUIRED;
1490                         else if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) &&
1491                                  strcmp(args[0].from, "imasig|modsig") == 0)
1492                                 entry->flags |= IMA_DIGSIG_REQUIRED |
1493                                                 IMA_MODSIG_ALLOWED;
1494                         else
1495                                 result = -EINVAL;
1496                         break;
1497                 case Opt_appraise_flag:
1498                         ima_log_string(ab, "appraise_flag", args[0].from);
1499                         if (IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG) &&
1500                             strstr(args[0].from, "blacklist"))
1501                                 entry->flags |= IMA_CHECK_BLACKLIST;
1502                         else
1503                                 result = -EINVAL;
1504                         break;
1505                 case Opt_permit_directio:
1506                         entry->flags |= IMA_PERMIT_DIRECTIO;
1507                         break;
1508                 case Opt_pcr:
1509                         ima_log_string(ab, "pcr", args[0].from);
1510
1511                         result = kstrtoint(args[0].from, 10, &entry->pcr);
1512                         if (result || INVALID_PCR(entry->pcr))
1513                                 result = -EINVAL;
1514                         else
1515                                 entry->flags |= IMA_PCR;
1516
1517                         break;
1518                 case Opt_template:
1519                         ima_log_string(ab, "template", args[0].from);
1520                         if (entry->action != MEASURE) {
1521                                 result = -EINVAL;
1522                                 break;
1523                         }
1524                         template_desc = lookup_template_desc(args[0].from);
1525                         if (!template_desc || entry->template) {
1526                                 result = -EINVAL;
1527                                 break;
1528                         }
1529
1530                         /*
1531                          * template_desc_init_fields() does nothing if
1532                          * the template is already initialised, so
1533                          * it's safe to do this unconditionally
1534                          */
1535                         template_desc_init_fields(template_desc->fmt,
1536                                                  &(template_desc->fields),
1537                                                  &(template_desc->num_fields));
1538                         entry->template = template_desc;
1539                         break;
1540                 case Opt_err:
1541                         ima_log_string(ab, "UNKNOWN", p);
1542                         result = -EINVAL;
1543                         break;
1544                 }
1545         }
1546         if (!result && !ima_validate_rule(entry))
1547                 result = -EINVAL;
1548         else if (entry->action == APPRAISE)
1549                 temp_ima_appraise |= ima_appraise_flag(entry->func);
1550
1551         if (!result && entry->flags & IMA_MODSIG_ALLOWED) {
1552                 template_desc = entry->template ? entry->template :
1553                                                   ima_template_desc_current();
1554                 check_template_modsig(template_desc);
1555         }
1556
1557         audit_log_format(ab, "res=%d", !result);
1558         audit_log_end(ab);
1559         return result;
1560 }
1561
1562 /**
1563  * ima_parse_add_rule - add a rule to ima_policy_rules
1564  * @rule - ima measurement policy rule
1565  *
1566  * Avoid locking by allowing just one writer at a time in ima_write_policy()
1567  * Returns the length of the rule parsed, an error code on failure
1568  */
1569 ssize_t ima_parse_add_rule(char *rule)
1570 {
1571         static const char op[] = "update_policy";
1572         char *p;
1573         struct ima_rule_entry *entry;
1574         ssize_t result, len;
1575         int audit_info = 0;
1576
1577         p = strsep(&rule, "\n");
1578         len = strlen(p) + 1;
1579         p += strspn(p, " \t");
1580
1581         if (*p == '#' || *p == '\0')
1582                 return len;
1583
1584         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1585         if (!entry) {
1586                 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
1587                                     NULL, op, "-ENOMEM", -ENOMEM, audit_info);
1588                 return -ENOMEM;
1589         }
1590
1591         INIT_LIST_HEAD(&entry->list);
1592
1593         result = ima_parse_rule(p, entry);
1594         if (result) {
1595                 ima_free_rule(entry);
1596                 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
1597                                     NULL, op, "invalid-policy", result,
1598                                     audit_info);
1599                 return result;
1600         }
1601
1602         list_add_tail(&entry->list, &ima_temp_rules);
1603
1604         return len;
1605 }
1606
1607 /**
1608  * ima_delete_rules() called to cleanup invalid in-flight policy.
1609  * We don't need locking as we operate on the temp list, which is
1610  * different from the active one.  There is also only one user of
1611  * ima_delete_rules() at a time.
1612  */
1613 void ima_delete_rules(void)
1614 {
1615         struct ima_rule_entry *entry, *tmp;
1616
1617         temp_ima_appraise = 0;
1618         list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) {
1619                 list_del(&entry->list);
1620                 ima_free_rule(entry);
1621         }
1622 }
1623
1624 #define __ima_hook_stringify(func, str) (#func),
1625
1626 const char *const func_tokens[] = {
1627         __ima_hooks(__ima_hook_stringify)
1628 };
1629
1630 #ifdef  CONFIG_IMA_READ_POLICY
1631 enum {
1632         mask_exec = 0, mask_write, mask_read, mask_append
1633 };
1634
1635 static const char *const mask_tokens[] = {
1636         "^MAY_EXEC",
1637         "^MAY_WRITE",
1638         "^MAY_READ",
1639         "^MAY_APPEND"
1640 };
1641
1642 void *ima_policy_start(struct seq_file *m, loff_t *pos)
1643 {
1644         loff_t l = *pos;
1645         struct ima_rule_entry *entry;
1646
1647         rcu_read_lock();
1648         list_for_each_entry_rcu(entry, ima_rules, list) {
1649                 if (!l--) {
1650                         rcu_read_unlock();
1651                         return entry;
1652                 }
1653         }
1654         rcu_read_unlock();
1655         return NULL;
1656 }
1657
1658 void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos)
1659 {
1660         struct ima_rule_entry *entry = v;
1661
1662         rcu_read_lock();
1663         entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list);
1664         rcu_read_unlock();
1665         (*pos)++;
1666
1667         return (&entry->list == ima_rules) ? NULL : entry;
1668 }
1669
1670 void ima_policy_stop(struct seq_file *m, void *v)
1671 {
1672 }
1673
1674 #define pt(token)       policy_tokens[token].pattern
1675 #define mt(token)       mask_tokens[token]
1676
1677 /*
1678  * policy_func_show - display the ima_hooks policy rule
1679  */
1680 static void policy_func_show(struct seq_file *m, enum ima_hooks func)
1681 {
1682         if (func > 0 && func < MAX_CHECK)
1683                 seq_printf(m, "func=%s ", func_tokens[func]);
1684         else
1685                 seq_printf(m, "func=%d ", func);
1686 }
1687
1688 static void ima_show_rule_opt_list(struct seq_file *m,
1689                                    const struct ima_rule_opt_list *opt_list)
1690 {
1691         size_t i;
1692
1693         for (i = 0; i < opt_list->count; i++)
1694                 seq_printf(m, "%s%s", i ? "|" : "", opt_list->items[i]);
1695 }
1696
1697 int ima_policy_show(struct seq_file *m, void *v)
1698 {
1699         struct ima_rule_entry *entry = v;
1700         int i;
1701         char tbuf[64] = {0,};
1702         int offset = 0;
1703
1704         rcu_read_lock();
1705
1706         if (entry->action & MEASURE)
1707                 seq_puts(m, pt(Opt_measure));
1708         if (entry->action & DONT_MEASURE)
1709                 seq_puts(m, pt(Opt_dont_measure));
1710         if (entry->action & APPRAISE)
1711                 seq_puts(m, pt(Opt_appraise));
1712         if (entry->action & DONT_APPRAISE)
1713                 seq_puts(m, pt(Opt_dont_appraise));
1714         if (entry->action & AUDIT)
1715                 seq_puts(m, pt(Opt_audit));
1716         if (entry->action & HASH)
1717                 seq_puts(m, pt(Opt_hash));
1718         if (entry->action & DONT_HASH)
1719                 seq_puts(m, pt(Opt_dont_hash));
1720
1721         seq_puts(m, " ");
1722
1723         if (entry->flags & IMA_FUNC)
1724                 policy_func_show(m, entry->func);
1725
1726         if ((entry->flags & IMA_MASK) || (entry->flags & IMA_INMASK)) {
1727                 if (entry->flags & IMA_MASK)
1728                         offset = 1;
1729                 if (entry->mask & MAY_EXEC)
1730                         seq_printf(m, pt(Opt_mask), mt(mask_exec) + offset);
1731                 if (entry->mask & MAY_WRITE)
1732                         seq_printf(m, pt(Opt_mask), mt(mask_write) + offset);
1733                 if (entry->mask & MAY_READ)
1734                         seq_printf(m, pt(Opt_mask), mt(mask_read) + offset);
1735                 if (entry->mask & MAY_APPEND)
1736                         seq_printf(m, pt(Opt_mask), mt(mask_append) + offset);
1737                 seq_puts(m, " ");
1738         }
1739
1740         if (entry->flags & IMA_FSMAGIC) {
1741                 snprintf(tbuf, sizeof(tbuf), "0x%lx", entry->fsmagic);
1742                 seq_printf(m, pt(Opt_fsmagic), tbuf);
1743                 seq_puts(m, " ");
1744         }
1745
1746         if (entry->flags & IMA_FSNAME) {
1747                 snprintf(tbuf, sizeof(tbuf), "%s", entry->fsname);
1748                 seq_printf(m, pt(Opt_fsname), tbuf);
1749                 seq_puts(m, " ");
1750         }
1751
1752         if (entry->flags & IMA_KEYRINGS) {
1753                 seq_puts(m, "keyrings=");
1754                 ima_show_rule_opt_list(m, entry->keyrings);
1755                 seq_puts(m, " ");
1756         }
1757
1758         if (entry->flags & IMA_LABEL) {
1759                 seq_puts(m, "label=");
1760                 ima_show_rule_opt_list(m, entry->label);
1761                 seq_puts(m, " ");
1762         }
1763
1764         if (entry->flags & IMA_PCR) {
1765                 snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
1766                 seq_printf(m, pt(Opt_pcr), tbuf);
1767                 seq_puts(m, " ");
1768         }
1769
1770         if (entry->flags & IMA_FSUUID) {
1771                 seq_printf(m, "fsuuid=%pU", &entry->fsuuid);
1772                 seq_puts(m, " ");
1773         }
1774
1775         if (entry->flags & IMA_UID) {
1776                 snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
1777                 if (entry->uid_op == &uid_gt)
1778                         seq_printf(m, pt(Opt_uid_gt), tbuf);
1779                 else if (entry->uid_op == &uid_lt)
1780                         seq_printf(m, pt(Opt_uid_lt), tbuf);
1781                 else
1782                         seq_printf(m, pt(Opt_uid_eq), tbuf);
1783                 seq_puts(m, " ");
1784         }
1785
1786         if (entry->flags & IMA_EUID) {
1787                 snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
1788                 if (entry->uid_op == &uid_gt)
1789                         seq_printf(m, pt(Opt_euid_gt), tbuf);
1790                 else if (entry->uid_op == &uid_lt)
1791                         seq_printf(m, pt(Opt_euid_lt), tbuf);
1792                 else
1793                         seq_printf(m, pt(Opt_euid_eq), tbuf);
1794                 seq_puts(m, " ");
1795         }
1796
1797         if (entry->flags & IMA_FOWNER) {
1798                 snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner));
1799                 if (entry->fowner_op == &uid_gt)
1800                         seq_printf(m, pt(Opt_fowner_gt), tbuf);
1801                 else if (entry->fowner_op == &uid_lt)
1802                         seq_printf(m, pt(Opt_fowner_lt), tbuf);
1803                 else
1804                         seq_printf(m, pt(Opt_fowner_eq), tbuf);
1805                 seq_puts(m, " ");
1806         }
1807
1808         for (i = 0; i < MAX_LSM_RULES; i++) {
1809                 if (entry->lsm[i].rule) {
1810                         switch (i) {
1811                         case LSM_OBJ_USER:
1812                                 seq_printf(m, pt(Opt_obj_user),
1813                                            entry->lsm[i].args_p);
1814                                 break;
1815                         case LSM_OBJ_ROLE:
1816                                 seq_printf(m, pt(Opt_obj_role),
1817                                            entry->lsm[i].args_p);
1818                                 break;
1819                         case LSM_OBJ_TYPE:
1820                                 seq_printf(m, pt(Opt_obj_type),
1821                                            entry->lsm[i].args_p);
1822                                 break;
1823                         case LSM_SUBJ_USER:
1824                                 seq_printf(m, pt(Opt_subj_user),
1825                                            entry->lsm[i].args_p);
1826                                 break;
1827                         case LSM_SUBJ_ROLE:
1828                                 seq_printf(m, pt(Opt_subj_role),
1829                                            entry->lsm[i].args_p);
1830                                 break;
1831                         case LSM_SUBJ_TYPE:
1832                                 seq_printf(m, pt(Opt_subj_type),
1833                                            entry->lsm[i].args_p);
1834                                 break;
1835                         }
1836                         seq_puts(m, " ");
1837                 }
1838         }
1839         if (entry->template)
1840                 seq_printf(m, "template=%s ", entry->template->name);
1841         if (entry->flags & IMA_DIGSIG_REQUIRED) {
1842                 if (entry->flags & IMA_MODSIG_ALLOWED)
1843                         seq_puts(m, "appraise_type=imasig|modsig ");
1844                 else
1845                         seq_puts(m, "appraise_type=imasig ");
1846         }
1847         if (entry->flags & IMA_CHECK_BLACKLIST)
1848                 seq_puts(m, "appraise_flag=check_blacklist ");
1849         if (entry->flags & IMA_PERMIT_DIRECTIO)
1850                 seq_puts(m, "permit_directio ");
1851         rcu_read_unlock();
1852         seq_puts(m, "\n");
1853         return 0;
1854 }
1855 #endif  /* CONFIG_IMA_READ_POLICY */
1856
1857 #if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING)
1858 /*
1859  * ima_appraise_signature: whether IMA will appraise a given function using
1860  * an IMA digital signature. This is restricted to cases where the kernel
1861  * has a set of built-in trusted keys in order to avoid an attacker simply
1862  * loading additional keys.
1863  */
1864 bool ima_appraise_signature(enum kernel_read_file_id id)
1865 {
1866         struct ima_rule_entry *entry;
1867         bool found = false;
1868         enum ima_hooks func;
1869
1870         if (id >= READING_MAX_ID)
1871                 return false;
1872
1873         func = read_idmap[id] ?: FILE_CHECK;
1874
1875         rcu_read_lock();
1876         list_for_each_entry_rcu(entry, ima_rules, list) {
1877                 if (entry->action != APPRAISE)
1878                         continue;
1879
1880                 /*
1881                  * A generic entry will match, but otherwise require that it
1882                  * match the func we're looking for
1883                  */
1884                 if (entry->func && entry->func != func)
1885                         continue;
1886
1887                 /*
1888                  * We require this to be a digital signature, not a raw IMA
1889                  * hash.
1890                  */
1891                 if (entry->flags & IMA_DIGSIG_REQUIRED)
1892                         found = true;
1893
1894                 /*
1895                  * We've found a rule that matches, so break now even if it
1896                  * didn't require a digital signature - a later rule that does
1897                  * won't override it, so would be a false positive.
1898                  */
1899                 break;
1900         }
1901
1902         rcu_read_unlock();
1903         return found;
1904 }
1905 #endif /* CONFIG_IMA_APPRAISE && CONFIG_INTEGRITY_TRUSTED_KEYRING */