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 #include <linux/binfmts.h>
   9 #include <linux/slab.h>
  10
  11 /* Variables definitions.*/
  12
  13 /* The initial domain. */
  14 struct tomoyo_domain_info tomoyo_kernel_domain;
  15
  16 /**
  17  * tomoyo_update_policy - Update an entry for exception policy.
  18  *
  19  * @new_entry:       Pointer to "struct tomoyo_acl_info".
  20  * @size:            Size of @new_entry in bytes.
  21  * @param:           Pointer to "struct tomoyo_acl_param".
  22  * @check_duplicate: Callback function to find duplicated entry.
  23  *
  24  * Returns 0 on success, negative value otherwise.
  25  *
  26  * Caller holds tomoyo_read_lock().
  27  */
  28 int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
  29                          struct tomoyo_acl_param *param,
  30                          bool (*check_duplicate) (const struct tomoyo_acl_head
  31                                                   *,
  32                                                   const struct tomoyo_acl_head
  33                                                   *))
  34 {
  35         int error = param->is_delete ? -ENOENT : -ENOMEM;
  36         struct tomoyo_acl_head *entry;
  37         struct list_head *list = param->list;
  38
  39         if (mutex_lock_interruptible(&tomoyo_policy_lock))
  40                 return -ENOMEM;
  41         list_for_each_entry_rcu(entry, list, list) {
  42                 if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
  43                         continue;
  44                 if (!check_duplicate(entry, new_entry))
  45                         continue;
  46                 entry->is_deleted = param->is_delete;
  47                 error = 0;
  48                 break;
  49         }
  50         if (error && !param->is_delete) {
  51                 entry = tomoyo_commit_ok(new_entry, size);
  52                 if (entry) {
  53                         list_add_tail_rcu(&entry->list, list);
  54                         error = 0;
  55                 }
  56         }
  57         mutex_unlock(&tomoyo_policy_lock);
  58         return error;
  59 }
  60
  61 /**
  62  * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry.
  63  *
  64  * @a: Pointer to "struct tomoyo_acl_info".
  65  * @b: Pointer to "struct tomoyo_acl_info".
  66  *
  67  * Returns true if @a == @b, false otherwise.
  68  */
  69 static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
  70                                         const struct tomoyo_acl_info *b)
  71 {
  72         return a->type == b->type && a->cond == b->cond;
  73 }
  74
  75 /**
  76  * tomoyo_update_domain - Update an entry for domain policy.
  77  *
  78  * @new_entry:       Pointer to "struct tomoyo_acl_info".
  79  * @size:            Size of @new_entry in bytes.
  80  * @param:           Pointer to "struct tomoyo_acl_param".
  81  * @check_duplicate: Callback function to find duplicated entry.
  82  * @merge_duplicate: Callback function to merge duplicated entry.
  83  *
  84  * Returns 0 on success, negative value otherwise.
  85  *
  86  * Caller holds tomoyo_read_lock().
  87  */
  88 int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
  89                          struct tomoyo_acl_param *param,
  90                          bool (*check_duplicate) (const struct tomoyo_acl_info
  91                                                   *,
  92                                                   const struct tomoyo_acl_info
  93                                                   *),
  94                          bool (*merge_duplicate) (struct tomoyo_acl_info *,
  95                                                   struct tomoyo_acl_info *,
  96                                                   const bool))
  97 {
  98         const bool is_delete = param->is_delete;
  99         int error = is_delete ? -ENOENT : -ENOMEM;
 100         struct tomoyo_acl_info *entry;
 101         struct list_head * const list = param->list;
 102
 103         if (param->data[0]) {
 104                 new_entry->cond = tomoyo_get_condition(param);
 105                 if (!new_entry->cond)
 106                         return -EINVAL;
 107                 /*
 108                  * Domain transition preference is allowed for only
 109                  * "file execute" entries.
 110                  */
 111                 if (new_entry->cond->transit &&
 112                     !(new_entry->type == TOMOYO_TYPE_PATH_ACL &&
 113                       container_of(new_entry, struct tomoyo_path_acl, head)
 114                       ->perm == 1 << TOMOYO_TYPE_EXECUTE))
 115                         goto out;
 116         }
 117         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 118                 goto out;
 119         list_for_each_entry_rcu(entry, list, list) {
 120                 if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
 121                         continue;
 122                 if (!tomoyo_same_acl_head(entry, new_entry) ||
 123                     !check_duplicate(entry, new_entry))
 124                         continue;
 125                 if (merge_duplicate)
 126                         entry->is_deleted = merge_duplicate(entry, new_entry,
 127                                                             is_delete);
 128                 else
 129                         entry->is_deleted = is_delete;
 130                 error = 0;
 131                 break;
 132         }
 133         if (error && !is_delete) {
 134                 entry = tomoyo_commit_ok(new_entry, size);
 135                 if (entry) {
 136                         list_add_tail_rcu(&entry->list, list);
 137                         error = 0;
 138                 }
 139         }
 140         mutex_unlock(&tomoyo_policy_lock);
 141 out:
 142         tomoyo_put_condition(new_entry->cond);
 143         return error;
 144 }
 145
 146 /**
 147  * tomoyo_check_acl - Do permission check.
 148  *
 149  * @r:           Pointer to "struct tomoyo_request_info".
 150  * @check_entry: Callback function to check type specific parameters.
 151  *
 152  * Returns 0 on success, negative value otherwise.
 153  *
 154  * Caller holds tomoyo_read_lock().
 155  */
 156 void tomoyo_check_acl(struct tomoyo_request_info *r,
 157                       bool (*check_entry) (struct tomoyo_request_info *,
 158                                            const struct tomoyo_acl_info *))
 159 {
 160         const struct tomoyo_domain_info *domain = r->domain;
 161         struct tomoyo_acl_info *ptr;
 162         bool retried = false;
 163         const struct list_head *list = &domain->acl_info_list;
 164
 165 retry:
 166         list_for_each_entry_rcu(ptr, list, list) {
 167                 if (ptr->is_deleted || ptr->type != r->param_type)
 168                         continue;
 169                 if (!check_entry(r, ptr))
 170                         continue;
 171                 if (!tomoyo_condition(r, ptr->cond))
 172                         continue;
 173                 r->matched_acl = ptr;
 174                 r->granted = true;
 175                 return;
 176         }
 177         if (!retried) {
 178                 retried = true;
 179                 list = &domain->ns->acl_group[domain->group];
 180                 goto retry;
 181         }
 182         r->granted = false;
 183 }
 184
 185 /* The list for "struct tomoyo_domain_info". */
 186 LIST_HEAD(tomoyo_domain_list);
 187
 188 /**
 189  * tomoyo_last_word - Get last component of a domainname.
 190  *
 191  * @name: Domainname to check.
 192  *
 193  * Returns the last word of @domainname.
 194  */
 195 static const char *tomoyo_last_word(const char *name)
 196 {
 197         const char *cp = strrchr(name, ' ');
 198         if (cp)
 199                 return cp + 1;
 200         return name;
 201 }
 202
 203 /**
 204  * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
 205  *
 206  * @a: Pointer to "struct tomoyo_acl_head".
 207  * @b: Pointer to "struct tomoyo_acl_head".
 208  *
 209  * Returns true if @a == @b, false otherwise.
 210  */
 211 static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
 212                                            const struct tomoyo_acl_head *b)
 213 {
 214         const struct tomoyo_transition_control *p1 = container_of(a,
 215                                                                   typeof(*p1),
 216                                                                   head);
 217         const struct tomoyo_transition_control *p2 = container_of(b,
 218                                                                   typeof(*p2),
 219                                                                   head);
 220         return p1->type == p2->type && p1->is_last_name == p2->is_last_name
 221                 && p1->domainname == p2->domainname
 222                 && p1->program == p2->program;
 223 }
 224
 225 /**
 226  * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
 227  *
 228  * @param: Pointer to "struct tomoyo_acl_param".
 229  * @type:  Type of this entry.
 230  *
 231  * Returns 0 on success, negative value otherwise.
 232  */
 233 int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
 234                                     const u8 type)
 235 {
 236         struct tomoyo_transition_control e = { .type = type };
 237         int error = param->is_delete ? -ENOENT : -ENOMEM;
 238         char *program = param->data;
 239         char *domainname = strstr(program, " from ");
 240         if (domainname) {
 241                 *domainname = '\0';
 242                 domainname += 6;
 243         } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
 244                    type == TOMOYO_TRANSITION_CONTROL_KEEP) {
 245                 domainname = program;
 246                 program = NULL;
 247         }
 248         if (program && strcmp(program, "any")) {
 249                 if (!tomoyo_correct_path(program))
 250                         return -EINVAL;
 251                 e.program = tomoyo_get_name(program);
 252                 if (!e.program)
 253                         goto out;
 254         }
 255         if (domainname && strcmp(domainname, "any")) {
 256                 if (!tomoyo_correct_domain(domainname)) {
 257                         if (!tomoyo_correct_path(domainname))
 258                                 goto out;
 259                         e.is_last_name = true;
 260                 }
 261                 e.domainname = tomoyo_get_name(domainname);
 262                 if (!e.domainname)
 263                         goto out;
 264         }
 265         param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
 266         error = tomoyo_update_policy(&e.head, sizeof(e), param,
 267                                      tomoyo_same_transition_control);
 268 out:
 269         tomoyo_put_name(e.domainname);
 270         tomoyo_put_name(e.program);
 271         return error;
 272 }
 273
 274 /**
 275  * tomoyo_scan_transition - Try to find specific domain transition type.
 276  *
 277  * @list:       Pointer to "struct list_head".
 278  * @domainname: The name of current domain.
 279  * @program:    The name of requested program.
 280  * @last_name:  The last component of @domainname.
 281  * @type:       One of values in "enum tomoyo_transition_type".
 282  *
 283  * Returns true if found one, false otherwise.
 284  *
 285  * Caller holds tomoyo_read_lock().
 286  */
 287 static inline bool tomoyo_scan_transition
 288 (const struct list_head *list, const struct tomoyo_path_info *domainname,
 289  const struct tomoyo_path_info *program, const char *last_name,
 290  const enum tomoyo_transition_type type)
 291 {
 292         const struct tomoyo_transition_control *ptr;
 293         list_for_each_entry_rcu(ptr, list, head.list) {
 294                 if (ptr->head.is_deleted || ptr->type != type)
 295                         continue;
 296                 if (ptr->domainname) {
 297                         if (!ptr->is_last_name) {
 298                                 if (ptr->domainname != domainname)
 299                                         continue;
 300                         } else {
 301                                 /*
 302                                  * Use direct strcmp() since this is
 303                                  * unlikely used.
 304                                  */
 305                                 if (strcmp(ptr->domainname->name, last_name))
 306                                         continue;
 307                         }
 308                 }
 309                 if (ptr->program && tomoyo_pathcmp(ptr->program, program))
 310                         continue;
 311                 return true;
 312         }
 313         return false;
 314 }
 315
 316 /**
 317  * tomoyo_transition_type - Get domain transition type.
 318  *
 319  * @ns:         Pointer to "struct tomoyo_policy_namespace".
 320  * @domainname: The name of current domain.
 321  * @program:    The name of requested program.
 322  *
 323  * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
 324  * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
 325  * executing @program reinitializes domain transition within that namespace,
 326  * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
 327  * others otherwise.
 328  *
 329  * Caller holds tomoyo_read_lock().
 330  */
 331 static enum tomoyo_transition_type tomoyo_transition_type
 332 (const struct tomoyo_policy_namespace *ns,
 333  const struct tomoyo_path_info *domainname,
 334  const struct tomoyo_path_info *program)
 335 {
 336         const char *last_name = tomoyo_last_word(domainname->name);
 337         enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
 338         while (type < TOMOYO_MAX_TRANSITION_TYPE) {
 339                 const struct list_head * const list =
 340                         &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
 341                 if (!tomoyo_scan_transition(list, domainname, program,
 342                                             last_name, type)) {
 343                         type++;
 344                         continue;
 345                 }
 346                 if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
 347                     type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
 348                         break;
 349                 /*
 350                  * Do not check for reset_domain if no_reset_domain matched.
 351                  * Do not check for initialize_domain if no_initialize_domain
 352                  * matched.
 353                  */
 354                 type++;
 355                 type++;
 356         }
 357         return type;
 358 }
 359
 360 /**
 361  * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
 362  *
 363  * @a: Pointer to "struct tomoyo_acl_head".
 364  * @b: Pointer to "struct tomoyo_acl_head".
 365  *
 366  * Returns true if @a == @b, false otherwise.
 367  */
 368 static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
 369                                    const struct tomoyo_acl_head *b)
 370 {
 371         const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
 372                                                           head);
 373         const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
 374                                                           head);
 375         return p1->original_name == p2->original_name &&
 376                 p1->aggregated_name == p2->aggregated_name;
 377 }
 378
 379 /**
 380  * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
 381  *
 382  * @param: Pointer to "struct tomoyo_acl_param".
 383  *
 384  * Returns 0 on success, negative value otherwise.
 385  *
 386  * Caller holds tomoyo_read_lock().
 387  */
 388 int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
 389 {
 390         struct tomoyo_aggregator e = { };
 391         int error = param->is_delete ? -ENOENT : -ENOMEM;
 392         const char *original_name = tomoyo_read_token(param);
 393         const char *aggregated_name = tomoyo_read_token(param);
 394         if (!tomoyo_correct_word(original_name) ||
 395             !tomoyo_correct_path(aggregated_name))
 396                 return -EINVAL;
 397         e.original_name = tomoyo_get_name(original_name);
 398         e.aggregated_name = tomoyo_get_name(aggregated_name);
 399         if (!e.original_name || !e.aggregated_name ||
 400             e.aggregated_name->is_patterned) /* No patterns allowed. */
 401                 goto out;
 402         param->list = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
 403         error = tomoyo_update_policy(&e.head, sizeof(e), param,
 404                                      tomoyo_same_aggregator);
 405 out:
 406         tomoyo_put_name(e.original_name);
 407         tomoyo_put_name(e.aggregated_name);
 408         return error;
 409 }
 410
 411 /**
 412  * tomoyo_find_namespace - Find specified namespace.
 413  *
 414  * @name: Name of namespace to find.
 415  * @len:  Length of @name.
 416  *
 417  * Returns pointer to "struct tomoyo_policy_namespace" if found,
 418  * NULL otherwise.
 419  *
 420  * Caller holds tomoyo_read_lock().
 421  */
 422 static struct tomoyo_policy_namespace *tomoyo_find_namespace
 423 (const char *name, const unsigned int len)
 424 {
 425         struct tomoyo_policy_namespace *ns;
 426         list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
 427                 if (strncmp(name, ns->name, len) ||
 428                     (name[len] && name[len] != ' '))
 429                         continue;
 430                 return ns;
 431         }
 432         return NULL;
 433 }
 434
 435 /**
 436  * tomoyo_assign_namespace - Create a new namespace.
 437  *
 438  * @domainname: Name of namespace to create.
 439  *
 440  * Returns pointer to "struct tomoyo_policy_namespace" on success,
 441  * NULL otherwise.
 442  *
 443  * Caller holds tomoyo_read_lock().
 444  */
 445 struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
 446 {
 447         struct tomoyo_policy_namespace *ptr;
 448         struct tomoyo_policy_namespace *entry;
 449         const char *cp = domainname;
 450         unsigned int len = 0;
 451         while (*cp && *cp++ != ' ')
 452                 len++;
 453         ptr = tomoyo_find_namespace(domainname, len);
 454         if (ptr)
 455                 return ptr;
 456         if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
 457                 return NULL;
 458         entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS);
 459         if (!entry)
 460                 return NULL;
 461         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 462                 goto out;
 463         ptr = tomoyo_find_namespace(domainname, len);
 464         if (!ptr && tomoyo_memory_ok(entry)) {
 465                 char *name = (char *) (entry + 1);
 466                 ptr = entry;
 467                 memmove(name, domainname, len);
 468                 name[len] = '\0';
 469                 entry->name = name;
 470                 tomoyo_init_policy_namespace(entry);
 471                 entry = NULL;
 472         }
 473         mutex_unlock(&tomoyo_policy_lock);
 474 out:
 475         kfree(entry);
 476         return ptr;
 477 }
 478
 479 /**
 480  * tomoyo_namespace_jump - Check for namespace jump.
 481  *
 482  * @domainname: Name of domain.
 483  *
 484  * Returns true if namespace differs, false otherwise.
 485  */
 486 static bool tomoyo_namespace_jump(const char *domainname)
 487 {
 488         const char *namespace = tomoyo_current_namespace()->name;
 489         const int len = strlen(namespace);
 490         return strncmp(domainname, namespace, len) ||
 491                 (domainname[len] && domainname[len] != ' ');
 492 }
 493
 494 /**
 495  * tomoyo_assign_domain - Create a domain or a namespace.
 496  *
 497  * @domainname: The name of domain.
 498  * @transit:    True if transit to domain found or created.
 499  *
 500  * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
 501  *
 502  * Caller holds tomoyo_read_lock().
 503  */
 504 struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
 505                                                 const bool transit)
 506 {
 507         struct tomoyo_domain_info e = { };
 508         struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
 509         bool created = false;
 510         if (entry) {
 511                 if (transit) {
 512                         /*
 513                          * Since namespace is created at runtime, profiles may
 514                          * not be created by the moment the process transits to
 515                          * that domain. Do not perform domain transition if
 516                          * profile for that domain is not yet created.
 517                          */
 518                         if (!entry->ns->profile_ptr[entry->profile])
 519                                 return NULL;
 520                 }
 521                 return entry;
 522         }
 523         /* Requested domain does not exist. */
 524         /* Don't create requested domain if domainname is invalid. */
 525         if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
 526             !tomoyo_correct_domain(domainname))
 527                 return NULL;
 528         /*
 529          * Since definition of profiles and acl_groups may differ across
 530          * namespaces, do not inherit "use_profile" and "use_group" settings
 531          * by automatically creating requested domain upon domain transition.
 532          */
 533         if (transit && tomoyo_namespace_jump(domainname))
 534                 return NULL;
 535         e.ns = tomoyo_assign_namespace(domainname);
 536         if (!e.ns)
 537                 return NULL;
 538         /*
 539          * "use_profile" and "use_group" settings for automatically created
 540          * domains are inherited from current domain. These are 0 for manually
 541          * created domains.
 542          */
 543         if (transit) {
 544                 const struct tomoyo_domain_info *domain = tomoyo_domain();
 545                 e.profile = domain->profile;
 546                 e.group = domain->group;
 547         }
 548         e.domainname = tomoyo_get_name(domainname);
 549         if (!e.domainname)
 550                 return NULL;
 551         if (mutex_lock_interruptible(&tomoyo_policy_lock))
 552                 goto out;
 553         entry = tomoyo_find_domain(domainname);
 554         if (!entry) {
 555                 entry = tomoyo_commit_ok(&e, sizeof(e));
 556                 if (entry) {
 557                         INIT_LIST_HEAD(&entry->acl_info_list);
 558                         list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
 559                         created = true;
 560                 }
 561         }
 562         mutex_unlock(&tomoyo_policy_lock);
 563 out:
 564         tomoyo_put_name(e.domainname);
 565         if (entry && transit) {
 566                 if (created) {
 567                         struct tomoyo_request_info r;
 568                         tomoyo_init_request_info(&r, entry,
 569                                                  TOMOYO_MAC_FILE_EXECUTE);
 570                         r.granted = false;
 571                         tomoyo_write_log(&r, "use_profile %u\n",
 572                                          entry->profile);
 573                         tomoyo_write_log(&r, "use_group %u\n", entry->group);
 574                         tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
 575                 }
 576         }
 577         return entry;
 578 }
 579
 580 /**
 581  * tomoyo_environ - Check permission for environment variable names.
 582  *
 583  * @ee: Pointer to "struct tomoyo_execve".
 584  *
 585  * Returns 0 on success, negative value otherwise.
 586  */
 587 static int tomoyo_environ(struct tomoyo_execve *ee)
 588 {
 589         struct tomoyo_request_info *r = &ee->r;
 590         struct linux_binprm *bprm = ee->bprm;
 591         /* env_page.data is allocated by tomoyo_dump_page(). */
 592         struct tomoyo_page_dump env_page = { };
 593         char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
 594         int arg_len = 0;
 595         unsigned long pos = bprm->p;
 596         int offset = pos % PAGE_SIZE;
 597         int argv_count = bprm->argc;
 598         int envp_count = bprm->envc;
 599         int error = -ENOMEM;
 600
 601         ee->r.type = TOMOYO_MAC_ENVIRON;
 602         ee->r.profile = r->domain->profile;
 603         ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
 604                                      TOMOYO_MAC_ENVIRON);
 605         if (!r->mode || !envp_count)
 606                 return 0;
 607         arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
 608         if (!arg_ptr)
 609                 goto out;
 610         while (error == -ENOMEM) {
 611                 if (!tomoyo_dump_page(bprm, pos, &env_page))
 612                         goto out;
 613                 pos += PAGE_SIZE - offset;
 614                 /* Read. */
 615                 while (argv_count && offset < PAGE_SIZE) {
 616                         if (!env_page.data[offset++])
 617                                 argv_count--;
 618                 }
 619                 if (argv_count) {
 620                         offset = 0;
 621                         continue;
 622                 }
 623                 while (offset < PAGE_SIZE) {
 624                         const unsigned char c = env_page.data[offset++];
 625
 626                         if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
 627                                 if (c == '=') {
 628                                         arg_ptr[arg_len++] = '\0';
 629                                 } else if (c == '\\') {
 630                                         arg_ptr[arg_len++] = '\\';
 631                                         arg_ptr[arg_len++] = '\\';
 632                                 } else if (c > ' ' && c < 127) {
 633                                         arg_ptr[arg_len++] = c;
 634                                 } else {
 635                                         arg_ptr[arg_len++] = '\\';
 636                                         arg_ptr[arg_len++] = (c >> 6) + '0';
 637                                         arg_ptr[arg_len++]
 638                                                 = ((c >> 3) & 7) + '0';
 639                                         arg_ptr[arg_len++] = (c & 7) + '0';
 640                                 }
 641                         } else {
 642                                 arg_ptr[arg_len] = '\0';
 643                         }
 644                         if (c)
 645                                 continue;
 646                         if (tomoyo_env_perm(r, arg_ptr)) {
 647                                 error = -EPERM;
 648                                 break;
 649                         }
 650                         if (!--envp_count) {
 651                                 error = 0;
 652                                 break;
 653                         }
 654                         arg_len = 0;
 655                 }
 656                 offset = 0;
 657         }
 658 out:
 659         if (r->mode != TOMOYO_CONFIG_ENFORCING)
 660                 error = 0;
 661         kfree(env_page.data);
 662         kfree(arg_ptr);
 663         return error;
 664 }
 665
 666 /**
 667  * tomoyo_find_next_domain - Find a domain.
 668  *
 669  * @bprm: Pointer to "struct linux_binprm".
 670  *
 671  * Returns 0 on success, negative value otherwise.
 672  *
 673  * Caller holds tomoyo_read_lock().
 674  */
 675 int tomoyo_find_next_domain(struct linux_binprm *bprm)
 676 {
 677         struct tomoyo_domain_info *old_domain = tomoyo_domain();
 678         struct tomoyo_domain_info *domain = NULL;
 679         const char *original_name = bprm->filename;
 680         int retval = -ENOMEM;
 681         bool reject_on_transition_failure = false;
 682         const struct tomoyo_path_info *candidate;
 683         struct tomoyo_path_info exename;
 684         struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
 685
 686         if (!ee)
 687                 return -ENOMEM;
 688         ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
 689         if (!ee->tmp) {
 690                 kfree(ee);
 691                 return -ENOMEM;
 692         }
 693         /* ee->dump->data is allocated by tomoyo_dump_page(). */
 694         tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
 695         ee->r.ee = ee;
 696         ee->bprm = bprm;
 697         ee->r.obj = &ee->obj;
 698         ee->obj.path1 = bprm->file->f_path;
 699         /* Get symlink's pathname of program. */
 700         retval = -ENOENT;
 701         exename.name = tomoyo_realpath_nofollow(original_name);
 702         if (!exename.name)
 703                 goto out;
 704         tomoyo_fill_path_info(&exename);
 705 retry:
 706         /* Check 'aggregator' directive. */
 707         {
 708                 struct tomoyo_aggregator *ptr;
 709                 struct list_head *list =
 710                         &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
 711                 /* Check 'aggregator' directive. */
 712                 candidate = &exename;
 713                 list_for_each_entry_rcu(ptr, list, head.list) {
 714                         if (ptr->head.is_deleted ||
 715                             !tomoyo_path_matches_pattern(&exename,
 716                                                          ptr->original_name))
 717                                 continue;
 718                         candidate = ptr->aggregated_name;
 719                         break;
 720                 }
 721         }
 722
 723         /* Check execute permission. */
 724         retval = tomoyo_execute_permission(&ee->r, candidate);
 725         if (retval == TOMOYO_RETRY_REQUEST)
 726                 goto retry;
 727         if (retval < 0)
 728                 goto out;
 729         /*
 730          * To be able to specify domainnames with wildcards, use the
 731          * pathname specified in the policy (which may contain
 732          * wildcard) rather than the pathname passed to execve()
 733          * (which never contains wildcard).
 734          */
 735         if (ee->r.param.path.matched_path)
 736                 candidate = ee->r.param.path.matched_path;
 737
 738         /*
 739          * Check for domain transition preference if "file execute" matched.
 740          * If preference is given, make do_execve() fail if domain transition
 741          * has failed, for domain transition preference should be used with
 742          * destination domain defined.
 743          */
 744         if (ee->transition) {
 745                 const char *domainname = ee->transition->name;
 746                 reject_on_transition_failure = true;
 747                 if (!strcmp(domainname, "keep"))
 748                         goto force_keep_domain;
 749                 if (!strcmp(domainname, "child"))
 750                         goto force_child_domain;
 751                 if (!strcmp(domainname, "reset"))
 752                         goto force_reset_domain;
 753                 if (!strcmp(domainname, "initialize"))
 754                         goto force_initialize_domain;
 755                 if (!strcmp(domainname, "parent")) {
 756                         char *cp;
 757                         strncpy(ee->tmp, old_domain->domainname->name,
 758                                 TOMOYO_EXEC_TMPSIZE - 1);
 759                         cp = strrchr(ee->tmp, ' ');
 760                         if (cp)
 761                                 *cp = '\0';
 762                 } else if (*domainname == '<')
 763                         strncpy(ee->tmp, domainname, TOMOYO_EXEC_TMPSIZE - 1);
 764                 else
 765                         snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
 766                                  old_domain->domainname->name, domainname);
 767                 goto force_jump_domain;
 768         }
 769         /*
 770          * No domain transition preference specified.
 771          * Calculate domain to transit to.
 772          */
 773         switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
 774                                        candidate)) {
 775         case TOMOYO_TRANSITION_CONTROL_RESET:
 776 force_reset_domain:
 777                 /* Transit to the root of specified namespace. */
 778                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>",
 779                          candidate->name);
 780                 /*
 781                  * Make do_execve() fail if domain transition across namespaces
 782                  * has failed.
 783                  */
 784                 reject_on_transition_failure = true;
 785                 break;
 786         case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
 787 force_initialize_domain:
 788                 /* Transit to the child of current namespace's root. */
 789                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
 790                          old_domain->ns->name, candidate->name);
 791                 break;
 792         case TOMOYO_TRANSITION_CONTROL_KEEP:
 793 force_keep_domain:
 794                 /* Keep current domain. */
 795                 domain = old_domain;
 796                 break;
 797         default:
 798                 if (old_domain == &tomoyo_kernel_domain &&
 799                     !tomoyo_policy_loaded) {
 800                         /*
 801                          * Needn't to transit from kernel domain before
 802                          * starting /sbin/init. But transit from kernel domain
 803                          * if executing initializers because they might start
 804                          * before /sbin/init.
 805                          */
 806                         domain = old_domain;
 807                         break;
 808                 }
 809 force_child_domain:
 810                 /* Normal domain transition. */
 811                 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
 812                          old_domain->domainname->name, candidate->name);
 813                 break;
 814         }
 815 force_jump_domain:
 816         if (!domain)
 817                 domain = tomoyo_assign_domain(ee->tmp, true);
 818         if (domain)
 819                 retval = 0;
 820         else if (reject_on_transition_failure) {
 821                 printk(KERN_WARNING "ERROR: Domain '%s' not ready.\n",
 822                        ee->tmp);
 823                 retval = -ENOMEM;
 824         } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
 825                 retval = -ENOMEM;
 826         else {
 827                 retval = 0;
 828                 if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
 829                         old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
 830                         ee->r.granted = false;
 831                         tomoyo_write_log(&ee->r, "%s", tomoyo_dif
 832                                          [TOMOYO_DIF_TRANSITION_FAILED]);
 833                         printk(KERN_WARNING
 834                                "ERROR: Domain '%s' not defined.\n", ee->tmp);
 835                 }
 836         }
 837  out:
 838         if (!domain)
 839                 domain = old_domain;
 840         /* Update reference count on "struct tomoyo_domain_info". */
 841         atomic_inc(&domain->users);
 842         bprm->cred->security = domain;
 843         kfree(exename.name);
 844         if (!retval) {
 845                 ee->r.domain = domain;
 846                 retval = tomoyo_environ(ee);
 847         }
 848         kfree(ee->tmp);
 849         kfree(ee->dump.data);
 850         kfree(ee);
 851         return retval;
 852 }
 853
 854 /**
 855  * tomoyo_dump_page - Dump a page to buffer.
 856  *
 857  * @bprm: Pointer to "struct linux_binprm".
 858  * @pos:  Location to dump.
 859  * @dump: Poiner to "struct tomoyo_page_dump".
 860  *
 861  * Returns true on success, false otherwise.
 862  */
 863 bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
 864                       struct tomoyo_page_dump *dump)
 865 {
 866         struct page *page;
 867
 868         /* dump->data is released by tomoyo_find_next_domain(). */
 869         if (!dump->data) {
 870                 dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
 871                 if (!dump->data)
 872                         return false;
 873         }
 874         /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
 875 #ifdef CONFIG_MMU
 876         if (get_user_pages(current, bprm->mm, pos, 1, 0, 1, &page, NULL) <= 0)
 877                 return false;
 878 #else
 879         page = bprm->page[pos / PAGE_SIZE];
 880 #endif
 881         if (page != dump->page) {
 882                 const unsigned int offset = pos % PAGE_SIZE;
 883                 /*
 884                  * Maybe kmap()/kunmap() should be used here.
 885                  * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
 886                  * So do I.
 887                  */
 888                 char *kaddr = kmap_atomic(page, KM_USER0);
 889
 890                 dump->page = page;
 891                 memcpy(dump->data + offset, kaddr + offset,
 892                        PAGE_SIZE - offset);
 893                 kunmap_atomic(kaddr, KM_USER0);
 894         }
 895         /* Same with put_arg_page(page) in fs/exec.c */
 896 #ifdef CONFIG_MMU
 897         put_page(page);
 898 #endif
 899         return true;
 900 }