security/tomoyo/domain.c

   1 /*
   2  * security/tomoyo/domain.c
   3  *
   4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
   5  */
   6
   7 #include "common.h"
   8
   9 #include <linux/binfmts.h>
  10 #include <linux/slab.h>
  11 #include <linux/rculist.h>
  12
  13 /* Variables definitions.*/
  14
  15 /* The initial domain. */
  16 struct tomoyo_domain_info tomoyo_kernel_domain;
  17
  18 /**
  19  * tomoyo_update_policy - Update an entry for exception policy.
  20  *
  21  * @new_entry:       Pointer to "struct tomoyo_acl_info".
  22  * @size:            Size of @new_entry in bytes.
  23  * @param:           Pointer to "struct tomoyo_acl_param".
  24  * @check_duplicate: Callback function to find duplicated entry.
  25  *
  26  * Returns 0 on success, negative value otherwise.
  27  *
  28  * Caller holds tomoyo_read_lock().
  29  */
  30 int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
  31                          struct tomoyo_acl_param *param,
  32                          bool (*check_duplicate) (const struct tomoyo_acl_head
  33                                                   *,
  34                                                   const struct tomoyo_acl_head
  35                                                   *))
  36 {
  37         int error = param->is_delete ? -ENOENT : -ENOMEM;
  38         struct tomoyo_acl_head *entry;
  39         struct list_head *list = param->list;
  40
  41         if (mutex_lock_interruptible(&tomoyo_policy_lock))
  42                 return -ENOMEM;
  43         list_for_each_entry_rcu(entry, list, list) {
  44                 if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
  45                         continue;
  46                 if (!check_duplicate(entry, new_entry))
  47                         continue;
  48                 entry->is_deleted = param->is_delete;
  49                 error = 0;
  50                 break;
  51         }
  52         if (error && !param->is_delete) {
  53                 entry = tomoyo_commit_ok(new_entry, size);
  54                 if (entry) {
  55                         list_add_tail_rcu(&entry->list, list);
  56                         error = 0;
  57                 }
  58         }
  59         mutex_unlock(&tomoyo_policy_lock);
  60         return error;
  61 }
  62
  63 /**
  64  * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry.
  65  *
  66  * @a: Pointer to "struct tomoyo_acl_info".
  67  * @b: Pointer to "struct tomoyo_acl_info".
  68  *
  69  * Returns true if @a == @b, false otherwise.
  70  */
  71 static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
  72                                         const struct tomoyo_acl_info *b)
  73 {
  74         return a->type == b->type && a->cond == b->cond;
  75 }
  76
  77 /**
  78  * tomoyo_update_domain - Update an entry for domain policy.
  79  *
  80  * @new_entry:       Pointer to "struct tomoyo_acl_info".
  81  * @size:            Size of @new_entry in bytes.
  82  * @param:           Pointer to "struct tomoyo_acl_param".
  83  * @check_duplicate: Callback function to find duplicated entry.
  84  * @merge_duplicate: Callback function to merge duplicated entry.
  85  *
  86  * Returns 0 on success, negative value otherwise.
  87  *
  88  * Caller holds tomoyo_read_lock().
  89  */
  90 int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
  91                          struct tomoyo_acl_param *param,
  92                          bool (*check_duplicate) (const struct tomoyo_acl_info
  93                                                   *,
  94                                                   const struct tomoyo_acl_info
  95                                                   *),
  96                          bool (*merge_duplicate) (struct tomoyo_acl_info *,
  97                                                   struct tomoyo_acl_info *,
  98                                                   const bool))
  99 {
 100         const bool is_delete = param->is_delete;
 101         int error = is_delete ? -ENOENT : -ENOMEM;
 102         struct tomoyo_acl_info *entry;
 103         struct list_head * const list = param->list;
 104
 105         if (param->data[0]) {
 106                 new_entry->cond = tomoyo_get_condition(param);
 107                 if (!new_entry->cond)
 108                         return -EINVAL;
 109                 /*
 110                  * Domain transition preference is allowed for only
 111                  * "file execute" entries.
 112                  */
 113                 if (new_entry->cond->transit &&
 114                     !(new_entry->type == TOMOYO_TYPE_PATH_ACL &&
 115                       container_of(new_entry, struct tomoyo_path_acl, head)
 116                       ->perm == 1 << TOMOYO_TYPE_EXECUTE))
 117                         goto out;
 118         }
 119         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 120                 goto out;
 121         list_for_each_entry_rcu(entry, list, list) {
 122                 if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
 123                         continue;
 124                 if (!tomoyo_same_acl_head(entry, new_entry) ||
 125                     !check_duplicate(entry, new_entry))
 126                         continue;
 127                 if (merge_duplicate)
 128                         entry->is_deleted = merge_duplicate(entry, new_entry,
 129                                                             is_delete);
 130                 else
 131                         entry->is_deleted = is_delete;
 132                 error = 0;
 133                 break;
 134         }
 135         if (error && !is_delete) {
 136                 entry = tomoyo_commit_ok(new_entry, size);
 137                 if (entry) {
 138                         list_add_tail_rcu(&entry->list, list);
 139                         error = 0;
 140                 }
 141         }
 142         mutex_unlock(&tomoyo_policy_lock);
 143 out:
 144         tomoyo_put_condition(new_entry->cond);
 145         return error;
 146 }
 147
 148 /**
 149  * tomoyo_check_acl - Do permission check.
 150  *
 151  * @r:           Pointer to "struct tomoyo_request_info".
 152  * @check_entry: Callback function to check type specific parameters.
 153  *
 154  * Returns 0 on success, negative value otherwise.
 155  *
 156  * Caller holds tomoyo_read_lock().
 157  */
 158 void tomoyo_check_acl(struct tomoyo_request_info *r,
 159                       bool (*check_entry) (struct tomoyo_request_info *,
 160                                            const struct tomoyo_acl_info *))
 161 {
 162         const struct tomoyo_domain_info *domain = r->domain;
 163         struct tomoyo_acl_info *ptr;
 164         bool retried = false;
 165         const struct list_head *list = &domain->acl_info_list;
 166
 167 retry:
 168         list_for_each_entry_rcu(ptr, list, list) {
 169                 if (ptr->is_deleted || ptr->type != r->param_type)
 170                         continue;
 171                 if (!check_entry(r, ptr))
 172                         continue;
 173                 if (!tomoyo_condition(r, ptr->cond))
 174                         continue;
 175                 r->matched_acl = ptr;
 176                 r->granted = true;
 177                 return;
 178         }
 179         if (!retried) {
 180                 retried = true;
 181                 list = &domain->ns->acl_group[domain->group];
 182                 goto retry;
 183         }
 184         r->granted = false;
 185 }
 186
 187 /* The list for "struct tomoyo_domain_info". */
 188 LIST_HEAD(tomoyo_domain_list);
 189
 190 /**
 191  * tomoyo_last_word - Get last component of a domainname.
 192  *
 193  * @name: Domainname to check.
 194  *
 195  * Returns the last word of @domainname.
 196  */
 197 static const char *tomoyo_last_word(const char *name)
 198 {
 199         const char *cp = strrchr(name, ' ');
 200         if (cp)
 201                 return cp + 1;
 202         return name;
 203 }
 204
 205 /**
 206  * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
 207  *
 208  * @a: Pointer to "struct tomoyo_acl_head".
 209  * @b: Pointer to "struct tomoyo_acl_head".
 210  *
 211  * Returns true if @a == @b, false otherwise.
 212  */
 213 static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
 214                                            const struct tomoyo_acl_head *b)
 215 {
 216         const struct tomoyo_transition_control *p1 = container_of(a,
 217                                                                   typeof(*p1),
 218                                                                   head);
 219         const struct tomoyo_transition_control *p2 = container_of(b,
 220                                                                   typeof(*p2),
 221                                                                   head);
 222         return p1->type == p2->type && p1->is_last_name == p2->is_last_name
 223                 && p1->domainname == p2->domainname
 224                 && p1->program == p2->program;
 225 }
 226
 227 /**
 228  * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
 229  *
 230  * @param: Pointer to "struct tomoyo_acl_param".
 231  * @type:  Type of this entry.
 232  *
 233  * Returns 0 on success, negative value otherwise.
 234  */
 235 int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
 236                                     const u8 type)
 237 {
 238         struct tomoyo_transition_control e = { .type = type };
 239         int error = param->is_delete ? -ENOENT : -ENOMEM;
 240         char *program = param->data;
 241         char *domainname = strstr(program, " from ");
 242         if (domainname) {
 243                 *domainname = '\0';
 244                 domainname += 6;
 245         } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
 246                    type == TOMOYO_TRANSITION_CONTROL_KEEP) {
 247                 domainname = program;
 248                 program = NULL;
 249         }
 250         if (program && strcmp(program, "any")) {
 251                 if (!tomoyo_correct_path(program))
 252                         return -EINVAL;
 253                 e.program = tomoyo_get_name(program);
 254                 if (!e.program)
 255                         goto out;
 256         }
 257         if (domainname && strcmp(domainname, "any")) {
 258                 if (!tomoyo_correct_domain(domainname)) {
 259                         if (!tomoyo_correct_path(domainname))
 260                                 goto out;
 261                         e.is_last_name = true;
 262                 }
 263                 e.domainname = tomoyo_get_name(domainname);
 264                 if (!e.domainname)
 265                         goto out;
 266         }
 267         param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
 268         error = tomoyo_update_policy(&e.head, sizeof(e), param,
 269                                      tomoyo_same_transition_control);
 270 out:
 271         tomoyo_put_name(e.domainname);
 272         tomoyo_put_name(e.program);
 273         return error;
 274 }
 275
 276 /**
 277  * tomoyo_scan_transition - Try to find specific domain transition type.
 278  *
 279  * @list:       Pointer to "struct list_head".
 280  * @domainname: The name of current domain.
 281  * @program:    The name of requested program.
 282  * @last_name:  The last component of @domainname.
 283  * @type:       One of values in "enum tomoyo_transition_type".
 284  *
 285  * Returns true if found one, false otherwise.
 286  *
 287  * Caller holds tomoyo_read_lock().
 288  */
 289 static inline bool tomoyo_scan_transition
 290 (const struct list_head *list, const struct tomoyo_path_info *domainname,
 291  const struct tomoyo_path_info *program, const char *last_name,
 292  const enum tomoyo_transition_type type)
 293 {
 294         const struct tomoyo_transition_control *ptr;
 295         list_for_each_entry_rcu(ptr, list, head.list) {
 296                 if (ptr->head.is_deleted || ptr->type != type)
 297                         continue;
 298                 if (ptr->domainname) {
 299                         if (!ptr->is_last_name) {
 300                                 if (ptr->domainname != domainname)
 301                                         continue;
 302                         } else {
 303                                 /*
 304                                  * Use direct strcmp() since this is
 305                                  * unlikely used.
 306                                  */
 307                                 if (strcmp(ptr->domainname->name, last_name))
 308                                         continue;
 309                         }
 310                 }
 311                 if (ptr->program && tomoyo_pathcmp(ptr->program, program))
 312                         continue;
 313                 return true;
 314         }
 315         return false;
 316 }
 317
 318 /**
 319  * tomoyo_transition_type - Get domain transition type.
 320  *
 321  * @ns:         Pointer to "struct tomoyo_policy_namespace".
 322  * @domainname: The name of current domain.
 323  * @program:    The name of requested program.
 324  *
 325  * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
 326  * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
 327  * executing @program reinitializes domain transition within that namespace,
 328  * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
 329  * others otherwise.
 330  *
 331  * Caller holds tomoyo_read_lock().
 332  */
 333 static enum tomoyo_transition_type tomoyo_transition_type
 334 (const struct tomoyo_policy_namespace *ns,
 335  const struct tomoyo_path_info *domainname,
 336  const struct tomoyo_path_info *program)
 337 {
 338         const char *last_name = tomoyo_last_word(domainname->name);
 339         enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
 340         while (type < TOMOYO_MAX_TRANSITION_TYPE) {
 341                 const struct list_head * const list =
 342                         &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
 343                 if (!tomoyo_scan_transition(list, domainname, program,
 344                                             last_name, type)) {
 345                         type++;
 346                         continue;
 347                 }
 348                 if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
 349                     type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
 350                         break;
 351                 /*
 352                  * Do not check for reset_domain if no_reset_domain matched.
 353                  * Do not check for initialize_domain if no_initialize_domain
 354                  * matched.
 355                  */
 356                 type++;
 357                 type++;
 358         }
 359         return type;
 360 }
 361
 362 /**
 363  * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
 364  *
 365  * @a: Pointer to "struct tomoyo_acl_head".
 366  * @b: Pointer to "struct tomoyo_acl_head".
 367  *
 368  * Returns true if @a == @b, false otherwise.
 369  */
 370 static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
 371                                    const struct tomoyo_acl_head *b)
 372 {
 373         const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
 374                                                           head);
 375         const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
 376                                                           head);
 377         return p1->original_name == p2->original_name &&
 378                 p1->aggregated_name == p2->aggregated_name;
 379 }
 380
 381 /**
 382  * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
 383  *
 384  * @param: Pointer to "struct tomoyo_acl_param".
 385  *
 386  * Returns 0 on success, negative value otherwise.
 387  *
 388  * Caller holds tomoyo_read_lock().
 389  */
 390 int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
 391 {
 392         struct tomoyo_aggregator e = { };
 393         int error = param->is_delete ? -ENOENT : -ENOMEM;
 394         const char *original_name = tomoyo_read_token(param);
 395         const char *aggregated_name = tomoyo_read_token(param);
 396         if (!tomoyo_correct_word(original_name) ||
 397             !tomoyo_correct_path(aggregated_name))
 398                 return -EINVAL;
 399         e.original_name = tomoyo_get_name(original_name);
 400         e.aggregated_name = tomoyo_get_name(aggregated_name);
 401         if (!e.original_name || !e.aggregated_name ||
 402             e.aggregated_name->is_patterned) /* No patterns allowed. */
 403                 goto out;
 404         param->list = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
 405         error = tomoyo_update_policy(&e.head, sizeof(e), param,
 406                                      tomoyo_same_aggregator);
 407 out:
 408         tomoyo_put_name(e.original_name);
 409         tomoyo_put_name(e.aggregated_name);
 410         return error;
 411 }
 412
 413 /**
 414  * tomoyo_find_namespace - Find specified namespace.
 415  *
 416  * @name: Name of namespace to find.
 417  * @len:  Length of @name.
 418  *
 419  * Returns pointer to "struct tomoyo_policy_namespace" if found,
 420  * NULL otherwise.
 421  *
 422  * Caller holds tomoyo_read_lock().
 423  */
 424 static struct tomoyo_policy_namespace *tomoyo_find_namespace
 425 (const char *name, const unsigned int len)
 426 {
 427         struct tomoyo_policy_namespace *ns;
 428         list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
 429                 if (strncmp(name, ns->name, len) ||
 430                     (name[len] && name[len] != ' '))
 431                         continue;
 432                 return ns;
 433         }
 434         return NULL;
 435 }
 436
 437 /**
 438  * tomoyo_assign_namespace - Create a new namespace.
 439  *
 440  * @domainname: Name of namespace to create.
 441  *
 442  * Returns pointer to "struct tomoyo_policy_namespace" on success,
 443  * NULL otherwise.
 444  *
 445  * Caller holds tomoyo_read_lock().
 446  */
 447 struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
 448 {
 449         struct tomoyo_policy_namespace *ptr;
 450         struct tomoyo_policy_namespace *entry;
 451         const char *cp = domainname;
 452         unsigned int len = 0;
 453         while (*cp && *cp++ != ' ')
 454                 len++;
 455         ptr = tomoyo_find_namespace(domainname, len);
 456         if (ptr)
 457                 return ptr;
 458         if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
 459                 return NULL;
 460         entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS);
 461         if (!entry)
 462                 return NULL;
 463         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 464                 goto out;
 465         ptr = tomoyo_find_namespace(domainname, len);
 466         if (!ptr && tomoyo_memory_ok(entry)) {
 467                 char *name = (char *) (entry + 1);
 468                 ptr = entry;
 469                 memmove(name, domainname, len);
 470                 name[len] = '\0';
 471                 entry->name = name;
 472                 tomoyo_init_policy_namespace(entry);
 473                 entry = NULL;
 474         }
 475         mutex_unlock(&tomoyo_policy_lock);
 476 out:
 477         kfree(entry);
 478         return ptr;
 479 }
 480
 481 /**
 482  * tomoyo_namespace_jump - Check for namespace jump.
 483  *
 484  * @domainname: Name of domain.
 485  *
 486  * Returns true if namespace differs, false otherwise.
 487  */
 488 static bool tomoyo_namespace_jump(const char *domainname)
 489 {
 490         const char *namespace = tomoyo_current_namespace()->name;
 491         const int len = strlen(namespace);
 492         return strncmp(domainname, namespace, len) ||
 493                 (domainname[len] && domainname[len] != ' ');
 494 }
 495
 496 /**
 497  * tomoyo_assign_domain - Create a domain or a namespace.
 498  *
 499  * @domainname: The name of domain.
 500  * @transit:    True if transit to domain found or created.
 501  *
 502  * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
 503  *
 504  * Caller holds tomoyo_read_lock().
 505  */
 506 struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
 507                                                 const bool transit)
 508 {
 509         struct tomoyo_domain_info e = { };
 510         struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
 511         bool created = false;
 512         if (entry) {
 513                 if (transit) {
 514                         /*
 515                          * Since namespace is created at runtime, profiles may
 516                          * not be created by the moment the process transits to
 517                          * that domain. Do not perform domain transition if
 518                          * profile for that domain is not yet created.
 519                          */
 520                         if (tomoyo_policy_loaded &&
 521                             !entry->ns->profile_ptr[entry->profile])
 522                                 return NULL;
 523                 }
 524                 return entry;
 525         }
 526         /* Requested domain does not exist. */
 527         /* Don't create requested domain if domainname is invalid. */
 528         if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
 529             !tomoyo_correct_domain(domainname))
 530                 return NULL;
 531         /*
 532          * Since definition of profiles and acl_groups may differ across
 533          * namespaces, do not inherit "use_profile" and "use_group" settings
 534          * by automatically creating requested domain upon domain transition.
 535          */
 536         if (transit && tomoyo_namespace_jump(domainname))
 537                 return NULL;
 538         e.ns = tomoyo_assign_namespace(domainname);
 539         if (!e.ns)
 540                 return NULL;
 541         /*
 542          * "use_profile" and "use_group" settings for automatically created
 543          * domains are inherited from current domain. These are 0 for manually
 544          * created domains.
 545          */
 546         if (transit) {
 547                 const struct tomoyo_domain_info *domain = tomoyo_domain();
 548                 e.profile = domain->profile;
 549                 e.group = domain->group;
 550         }
 551         e.domainname = tomoyo_get_name(domainname);
 552         if (!e.domainname)
 553                 return NULL;
 554         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 555                 goto out;
 556         entry = tomoyo_find_domain(domainname);
 557         if (!entry) {
 558                 entry = tomoyo_commit_ok(&e, sizeof(e));
 559                 if (entry) {
 560                         INIT_LIST_HEAD(&entry->acl_info_list);
 561                         list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
 562                         created = true;
 563                 }
 564         }
 565         mutex_unlock(&tomoyo_policy_lock);
 566 out:
 567         tomoyo_put_name(e.domainname);
 568         if (entry && transit) {
 569                 if (created) {
 570                         struct tomoyo_request_info r;
 571                         tomoyo_init_request_info(&r, entry,
 572                                                  TOMOYO_MAC_FILE_EXECUTE);
 573                         r.granted = false;
 574                         tomoyo_write_log(&r, "use_profile %u\n",
 575                                          entry->profile);
 576                         tomoyo_write_log(&r, "use_group %u\n", entry->group);
 577                         tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
 578                 }
 579         }
 580         return entry;
 581 }
 582
 583 /**
 584  * tomoyo_environ - Check permission for environment variable names.
 585  *
 586  * @ee: Pointer to "struct tomoyo_execve".
 587  *
 588  * Returns 0 on success, negative value otherwise.
 589  */
 590 static int tomoyo_environ(struct tomoyo_execve *ee)
 591 {
 592         struct tomoyo_request_info *r = &ee->r;
 593         struct linux_binprm *bprm = ee->bprm;
 594         /* env_page.data is allocated by tomoyo_dump_page(). */
 595         struct tomoyo_page_dump env_page = { };
 596         char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
 597         int arg_len = 0;
 598         unsigned long pos = bprm->p;
 599         int offset = pos % PAGE_SIZE;
 600         int argv_count = bprm->argc;
 601         int envp_count = bprm->envc;
 602         int error = -ENOMEM;
 603
 604         ee->r.type = TOMOYO_MAC_ENVIRON;
 605         ee->r.profile = r->domain->profile;
 606         ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
 607                                      TOMOYO_MAC_ENVIRON);
 608         if (!r->mode || !envp_count)
 609                 return 0;
 610         arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
 611         if (!arg_ptr)
 612                 goto out;
 613         while (error == -ENOMEM) {
 614                 if (!tomoyo_dump_page(bprm, pos, &env_page))
 615                         goto out;
 616                 pos += PAGE_SIZE - offset;
 617                 /* Read. */
 618                 while (argv_count && offset < PAGE_SIZE) {
 619                         if (!env_page.data[offset++])
 620                                 argv_count--;
 621                 }
 622                 if (argv_count) {
 623                         offset = 0;
 624                         continue;
 625                 }
 626                 while (offset < PAGE_SIZE) {
 627                         const unsigned char c = env_page.data[offset++];
 628
 629                         if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
 630                                 if (c == '=') {
 631                                         arg_ptr[arg_len++] = '\0';
 632                                 } else if (c == '\\') {
 633                                         arg_ptr[arg_len++] = '\\';
 634                                         arg_ptr[arg_len++] = '\\';
 635                                 } else if (c > ' ' && c < 127) {
 636                                         arg_ptr[arg_len++] = c;
 637                                 } else {
 638                                         arg_ptr[arg_len++] = '\\';
 639                                         arg_ptr[arg_len++] = (c >> 6) + '0';
 640                                         arg_ptr[arg_len++]
 641                                                 = ((c >> 3) & 7) + '0';
 642                                         arg_ptr[arg_len++] = (c & 7) + '0';
 643                                 }
 644                         } else {
 645                                 arg_ptr[arg_len] = '\0';
 646                         }
 647                         if (c)
 648                                 continue;
 649                         if (tomoyo_env_perm(r, arg_ptr)) {
 650                                 error = -EPERM;
 651                                 break;
 652                         }
 653                         if (!--envp_count) {
 654                                 error = 0;
 655                                 break;
 656                         }
 657                         arg_len = 0;
 658                 }
 659                 offset = 0;
 660         }
 661 out:
 662         if (r->mode != TOMOYO_CONFIG_ENFORCING)
 663                 error = 0;
 664         kfree(env_page.data);
 665         kfree(arg_ptr);
 666         return error;
 667 }
 668
 669 /**
 670  * tomoyo_find_next_domain - Find a domain.
 671  *
 672  * @bprm: Pointer to "struct linux_binprm".
 673  *
 674  * Returns 0 on success, negative value otherwise.
 675  *
 676  * Caller holds tomoyo_read_lock().
 677  */
 678 int tomoyo_find_next_domain(struct linux_binprm *bprm)
 679 {
 680         struct tomoyo_domain_info *old_domain = tomoyo_domain();
 681         struct tomoyo_domain_info *domain = NULL;
 682         const char *original_name = bprm->filename;
 683         int retval = -ENOMEM;
 684         bool reject_on_transition_failure = false;
 685         const struct tomoyo_path_info *candidate;
 686         struct tomoyo_path_info exename;
 687         struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
 688
 689         if (!ee)
 690                 return -ENOMEM;
 691         ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
 692         if (!ee->tmp) {
 693                 kfree(ee);
 694                 return -ENOMEM;
 695         }
 696         /* ee->dump->data is allocated by tomoyo_dump_page(). */
 697         tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
 698         ee->r.ee = ee;
 699         ee->bprm = bprm;
 700         ee->r.obj = &ee->obj;
 701         ee->obj.path1 = bprm->file->f_path;
 702         /* Get symlink's pathname of program. */
 703         retval = -ENOENT;
 704         exename.name = tomoyo_realpath_nofollow(original_name);
 705         if (!exename.name)
 706                 goto out;
 707         tomoyo_fill_path_info(&exename);
 708 retry:
 709         /* Check 'aggregator' directive. */
 710         {
 711                 struct tomoyo_aggregator *ptr;
 712                 struct list_head *list =
 713                         &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
 714                 /* Check 'aggregator' directive. */
 715                 candidate = &exename;
 716                 list_for_each_entry_rcu(ptr, list, head.list) {
 717                         if (ptr->head.is_deleted ||
 718                             !tomoyo_path_matches_pattern(&exename,
 719                                                          ptr->original_name))
 720                                 continue;
 721                         candidate = ptr->aggregated_name;
 722                         break;
 723                 }
 724         }
 725
 726         /* Check execute permission. */
 727         retval = tomoyo_execute_permission(&ee->r, candidate);
 728         if (retval == TOMOYO_RETRY_REQUEST)
 729                 goto retry;
 730         if (retval < 0)
 731                 goto out;
 732         /*
 733          * To be able to specify domainnames with wildcards, use the
 734          * pathname specified in the policy (which may contain
 735          * wildcard) rather than the pathname passed to execve()
 736          * (which never contains wildcard).
 737          */
 738         if (ee->r.param.path.matched_path)
 739                 candidate = ee->r.param.path.matched_path;
 740
 741         /*
 742          * Check for domain transition preference if "file execute" matched.
 743          * If preference is given, make do_execve() fail if domain transition
 744          * has failed, for domain transition preference should be used with
 745          * destination domain defined.
 746          */
 747         if (ee->transition) {
 748                 const char *domainname = ee->transition->name;
 749                 reject_on_transition_failure = true;
 750                 if (!strcmp(domainname, "keep"))
 751                         goto force_keep_domain;
 752                 if (!strcmp(domainname, "child"))
 753                         goto force_child_domain;
 754                 if (!strcmp(domainname, "reset"))
 755                         goto force_reset_domain;
 756                 if (!strcmp(domainname, "initialize"))
 757                         goto force_initialize_domain;
 758                 if (!strcmp(domainname, "parent")) {
 759                         char *cp;
 760                         strncpy(ee->tmp, old_domain->domainname->name,
 761                                 TOMOYO_EXEC_TMPSIZE - 1);
 762                         cp = strrchr(ee->tmp, ' ');
 763                         if (cp)
 764                                 *cp = '\0';
 765                 } else if (*domainname == '<')
 766                         strncpy(ee->tmp, domainname, TOMOYO_EXEC_TMPSIZE - 1);
 767                 else
 768                         snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
 769                                  old_domain->domainname->name, domainname);
 770                 goto force_jump_domain;
 771         }
 772         /*
 773          * No domain transition preference specified.
 774          * Calculate domain to transit to.
 775          */
 776         switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
 777                                        candidate)) {
 778         case TOMOYO_TRANSITION_CONTROL_RESET:
 779 force_reset_domain:
 780                 /* Transit to the root of specified namespace. */
 781                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>",
 782                          candidate->name);
 783                 /*
 784                  * Make do_execve() fail if domain transition across namespaces
 785                  * has failed.
 786                  */
 787                 reject_on_transition_failure = true;
 788                 break;
 789         case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
 790 force_initialize_domain:
 791                 /* Transit to the child of current namespace's root. */
 792                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
 793                          old_domain->ns->name, candidate->name);
 794                 break;
 795         case TOMOYO_TRANSITION_CONTROL_KEEP:
 796 force_keep_domain:
 797                 /* Keep current domain. */
 798                 domain = old_domain;
 799                 break;
 800         default:
 801                 if (old_domain == &tomoyo_kernel_domain &&
 802                     !tomoyo_policy_loaded) {
 803                         /*
 804                          * Needn't to transit from kernel domain before
 805                          * starting /sbin/init. But transit from kernel domain
 806                          * if executing initializers because they might start
 807                          * before /sbin/init.
 808                          */
 809                         domain = old_domain;
 810                         break;
 811                 }
 812 force_child_domain:
 813                 /* Normal domain transition. */
 814                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
 815                          old_domain->domainname->name, candidate->name);
 816                 break;
 817         }
 818 force_jump_domain:
 819         if (!domain)
 820                 domain = tomoyo_assign_domain(ee->tmp, true);
 821         if (domain)
 822                 retval = 0;
 823         else if (reject_on_transition_failure) {
 824                 printk(KERN_WARNING "ERROR: Domain '%s' not ready.\n",
 825                        ee->tmp);
 826                 retval = -ENOMEM;
 827         } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
 828                 retval = -ENOMEM;
 829         else {
 830                 retval = 0;
 831                 if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
 832                         old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
 833                         ee->r.granted = false;
 834                         tomoyo_write_log(&ee->r, "%s", tomoyo_dif
 835                                          [TOMOYO_DIF_TRANSITION_FAILED]);
 836                         printk(KERN_WARNING
 837                                "ERROR: Domain '%s' not defined.\n", ee->tmp);
 838                 }
 839         }
 840  out:
 841         if (!domain)
 842                 domain = old_domain;
 843         /* Update reference count on "struct tomoyo_domain_info". */
 844         atomic_inc(&domain->users);
 845         bprm->cred->security = domain;
 846         kfree(exename.name);
 847         if (!retval) {
 848                 ee->r.domain = domain;
 849                 retval = tomoyo_environ(ee);
 850         }
 851         kfree(ee->tmp);
 852         kfree(ee->dump.data);
 853         kfree(ee);
 854         return retval;
 855 }
 856
 857 /**
 858  * tomoyo_dump_page - Dump a page to buffer.
 859  *
 860  * @bprm: Pointer to "struct linux_binprm".
 861  * @pos:  Location to dump.
 862  * @dump: Poiner to "struct tomoyo_page_dump".
 863  *
 864  * Returns true on success, false otherwise.
 865  */
 866 bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
 867                       struct tomoyo_page_dump *dump)
 868 {
 869         struct page *page;
 870
 871         /* dump->data is released by tomoyo_find_next_domain(). */
 872         if (!dump->data) {
 873                 dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
 874                 if (!dump->data)
 875                         return false;
 876         }
 877         /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
 878 #ifdef CONFIG_MMU
 879         /*
 880          * This is called at execve() time in order to dig around
 881          * in the argv/environment of the new proceess
 882          * (represented by bprm).  'current' is the process doing
 883          * the execve().
 884          */
 885         if (get_user_pages_remote(current, bprm->mm, pos, 1,
 886                                 FOLL_FORCE, &page, NULL, NULL) <= 0)
 887                 return false;
 888 #else
 889         page = bprm->page[pos / PAGE_SIZE];
 890 #endif
 891         if (page != dump->page) {
 892                 const unsigned int offset = pos % PAGE_SIZE;
 893                 /*
 894                  * Maybe kmap()/kunmap() should be used here.
 895                  * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
 896                  * So do I.
 897                  */
 898                 char *kaddr = kmap_atomic(page);
 899
 900                 dump->page = page;
 901                 memcpy(dump->data + offset, kaddr + offset,
 902                        PAGE_SIZE - offset);
 903                 kunmap_atomic(kaddr);
 904         }
 905         /* Same with put_arg_page(page) in fs/exec.c */
 906 #ifdef CONFIG_MMU
 907         put_page(page);
 908 #endif
 909         return true;
 910 }