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