security/tomoyo/condition.c

   1 /*
   2  * security/tomoyo/condition.c
   3  *
   4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
   5  */
   6
   7 #include "common.h"
   8 #include <linux/slab.h>
   9
  10 /* List of "struct tomoyo_condition". */
  11 LIST_HEAD(tomoyo_condition_list);
  12
  13 /**
  14  * tomoyo_argv - Check argv[] in "struct linux_binbrm".
  15  *
  16  * @index:   Index number of @arg_ptr.
  17  * @arg_ptr: Contents of argv[@index].
  18  * @argc:    Length of @argv.
  19  * @argv:    Pointer to "struct tomoyo_argv".
  20  * @checked: Set to true if @argv[@index] was found.
  21  *
  22  * Returns true on success, false otherwise.
  23  */
  24 static bool tomoyo_argv(const unsigned int index, const char *arg_ptr,
  25                         const int argc, const struct tomoyo_argv *argv,
  26                         u8 *checked)
  27 {
  28         int i;
  29         struct tomoyo_path_info arg;
  30         arg.name = arg_ptr;
  31         for (i = 0; i < argc; argv++, checked++, i++) {
  32                 bool result;
  33                 if (index != argv->index)
  34                         continue;
  35                 *checked = 1;
  36                 tomoyo_fill_path_info(&arg);
  37                 result = tomoyo_path_matches_pattern(&arg, argv->value);
  38                 if (argv->is_not)
  39                         result = !result;
  40                 if (!result)
  41                         return false;
  42         }
  43         return true;
  44 }
  45
  46 /**
  47  * tomoyo_envp - Check envp[] in "struct linux_binbrm".
  48  *
  49  * @env_name:  The name of environment variable.
  50  * @env_value: The value of environment variable.
  51  * @envc:      Length of @envp.
  52  * @envp:      Pointer to "struct tomoyo_envp".
  53  * @checked:   Set to true if @envp[@env_name] was found.
  54  *
  55  * Returns true on success, false otherwise.
  56  */
  57 static bool tomoyo_envp(const char *env_name, const char *env_value,
  58                         const int envc, const struct tomoyo_envp *envp,
  59                         u8 *checked)
  60 {
  61         int i;
  62         struct tomoyo_path_info name;
  63         struct tomoyo_path_info value;
  64         name.name = env_name;
  65         tomoyo_fill_path_info(&name);
  66         value.name = env_value;
  67         tomoyo_fill_path_info(&value);
  68         for (i = 0; i < envc; envp++, checked++, i++) {
  69                 bool result;
  70                 if (!tomoyo_path_matches_pattern(&name, envp->name))
  71                         continue;
  72                 *checked = 1;
  73                 if (envp->value) {
  74                         result = tomoyo_path_matches_pattern(&value,
  75                                                              envp->value);
  76                         if (envp->is_not)
  77                                 result = !result;
  78                 } else {
  79                         result = true;
  80                         if (!envp->is_not)
  81                                 result = !result;
  82                 }
  83                 if (!result)
  84                         return false;
  85         }
  86         return true;
  87 }
  88
  89 /**
  90  * tomoyo_scan_bprm - Scan "struct linux_binprm".
  91  *
  92  * @ee:   Pointer to "struct tomoyo_execve".
  93  * @argc: Length of @argc.
  94  * @argv: Pointer to "struct tomoyo_argv".
  95  * @envc: Length of @envp.
  96  * @envp: Poiner to "struct tomoyo_envp".
  97  *
  98  * Returns true on success, false otherwise.
  99  */
 100 static bool tomoyo_scan_bprm(struct tomoyo_execve *ee,
 101                              const u16 argc, const struct tomoyo_argv *argv,
 102                              const u16 envc, const struct tomoyo_envp *envp)
 103 {
 104         struct linux_binprm *bprm = ee->bprm;
 105         struct tomoyo_page_dump *dump = &ee->dump;
 106         char *arg_ptr = ee->tmp;
 107         int arg_len = 0;
 108         unsigned long pos = bprm->p;
 109         int offset = pos % PAGE_SIZE;
 110         int argv_count = bprm->argc;
 111         int envp_count = bprm->envc;
 112         bool result = true;
 113         u8 local_checked[32];
 114         u8 *checked;
 115         if (argc + envc <= sizeof(local_checked)) {
 116                 checked = local_checked;
 117                 memset(local_checked, 0, sizeof(local_checked));
 118         } else {
 119                 checked = kzalloc(argc + envc, GFP_NOFS);
 120                 if (!checked)
 121                         return false;
 122         }
 123         while (argv_count || envp_count) {
 124                 if (!tomoyo_dump_page(bprm, pos, dump)) {
 125                         result = false;
 126                         goto out;
 127                 }
 128                 pos += PAGE_SIZE - offset;
 129                 while (offset < PAGE_SIZE) {
 130                         /* Read. */
 131                         const char *kaddr = dump->data;
 132                         const unsigned char c = kaddr[offset++];
 133                         if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
 134                                 if (c == '\\') {
 135                                         arg_ptr[arg_len++] = '\\';
 136                                         arg_ptr[arg_len++] = '\\';
 137                                 } else if (c > ' ' && c < 127) {
 138                                         arg_ptr[arg_len++] = c;
 139                                 } else {
 140                                         arg_ptr[arg_len++] = '\\';
 141                                         arg_ptr[arg_len++] = (c >> 6) + '0';
 142                                         arg_ptr[arg_len++] =
 143                                                 ((c >> 3) & 7) + '0';
 144                                         arg_ptr[arg_len++] = (c & 7) + '0';
 145                                 }
 146                         } else {
 147                                 arg_ptr[arg_len] = '\0';
 148                         }
 149                         if (c)
 150                                 continue;
 151                         /* Check. */
 152                         if (argv_count) {
 153                                 if (!tomoyo_argv(bprm->argc - argv_count,
 154                                                  arg_ptr, argc, argv,
 155                                                  checked)) {
 156                                         result = false;
 157                                         break;
 158                                 }
 159                                 argv_count--;
 160                         } else if (envp_count) {
 161                                 char *cp = strchr(arg_ptr, '=');
 162                                 if (cp) {
 163                                         *cp = '\0';
 164                                         if (!tomoyo_envp(arg_ptr, cp + 1,
 165                                                          envc, envp,
 166                                                          checked + argc)) {
 167                                                 result = false;
 168                                                 break;
 169                                         }
 170                                 }
 171                                 envp_count--;
 172                         } else {
 173                                 break;
 174                         }
 175                         arg_len = 0;
 176                 }
 177                 offset = 0;
 178                 if (!result)
 179                         break;
 180         }
 181 out:
 182         if (result) {
 183                 int i;
 184                 /* Check not-yet-checked entries. */
 185                 for (i = 0; i < argc; i++) {
 186                         if (checked[i])
 187                                 continue;
 188                         /*
 189                          * Return true only if all unchecked indexes in
 190                          * bprm->argv[] are not matched.
 191                          */
 192                         if (argv[i].is_not)
 193                                 continue;
 194                         result = false;
 195                         break;
 196                 }
 197                 for (i = 0; i < envc; envp++, i++) {
 198                         if (checked[argc + i])
 199                                 continue;
 200                         /*
 201                          * Return true only if all unchecked environ variables
 202                          * in bprm->envp[] are either undefined or not matched.
 203                          */
 204                         if ((!envp->value && !envp->is_not) ||
 205                             (envp->value && envp->is_not))
 206                                 continue;
 207                         result = false;
 208                         break;
 209                 }
 210         }
 211         if (checked != local_checked)
 212                 kfree(checked);
 213         return result;
 214 }
 215
 216 /**
 217  * tomoyo_scan_exec_realpath - Check "exec.realpath" parameter of "struct tomoyo_condition".
 218  *
 219  * @file:  Pointer to "struct file".
 220  * @ptr:   Pointer to "struct tomoyo_name_union".
 221  * @match: True if "exec.realpath=", false if "exec.realpath!=".
 222  *
 223  * Returns true on success, false otherwise.
 224  */
 225 static bool tomoyo_scan_exec_realpath(struct file *file,
 226                                       const struct tomoyo_name_union *ptr,
 227                                       const bool match)
 228 {
 229         bool result;
 230         struct tomoyo_path_info exe;
 231         if (!file)
 232                 return false;
 233         exe.name = tomoyo_realpath_from_path(&file->f_path);
 234         if (!exe.name)
 235                 return false;
 236         tomoyo_fill_path_info(&exe);
 237         result = tomoyo_compare_name_union(&exe, ptr);
 238         kfree(exe.name);
 239         return result == match;
 240 }
 241
 242 /**
 243  * tomoyo_get_dqword - tomoyo_get_name() for a quoted string.
 244  *
 245  * @start: String to save.
 246  *
 247  * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
 248  */
 249 static const struct tomoyo_path_info *tomoyo_get_dqword(char *start)
 250 {
 251         char *cp = start + strlen(start) - 1;
 252         if (cp == start || *start++ != '"' || *cp != '"')
 253                 return NULL;
 254         *cp = '\0';
 255         if (*start && !tomoyo_correct_word(start))
 256                 return NULL;
 257         return tomoyo_get_name(start);
 258 }
 259
 260 /**
 261  * tomoyo_parse_name_union_quoted - Parse a quoted word.
 262  *
 263  * @param: Pointer to "struct tomoyo_acl_param".
 264  * @ptr:   Pointer to "struct tomoyo_name_union".
 265  *
 266  * Returns true on success, false otherwise.
 267  */
 268 static bool tomoyo_parse_name_union_quoted(struct tomoyo_acl_param *param,
 269                                            struct tomoyo_name_union *ptr)
 270 {
 271         char *filename = param->data;
 272         if (*filename == '@')
 273                 return tomoyo_parse_name_union(param, ptr);
 274         ptr->filename = tomoyo_get_dqword(filename);
 275         return ptr->filename != NULL;
 276 }
 277
 278 /**
 279  * tomoyo_parse_argv - Parse an argv[] condition part.
 280  *
 281  * @left:  Lefthand value.
 282  * @right: Righthand value.
 283  * @argv:  Pointer to "struct tomoyo_argv".
 284  *
 285  * Returns true on success, false otherwise.
 286  */
 287 static bool tomoyo_parse_argv(char *left, char *right,
 288                               struct tomoyo_argv *argv)
 289 {
 290         if (tomoyo_parse_ulong(&argv->index, &left) !=
 291             TOMOYO_VALUE_TYPE_DECIMAL || *left++ != ']' || *left)
 292                 return false;
 293         argv->value = tomoyo_get_dqword(right);
 294         return argv->value != NULL;
 295 }
 296
 297 /**
 298  * tomoyo_parse_envp - Parse an envp[] condition part.
 299  *
 300  * @left:  Lefthand value.
 301  * @right: Righthand value.
 302  * @envp:  Pointer to "struct tomoyo_envp".
 303  *
 304  * Returns true on success, false otherwise.
 305  */
 306 static bool tomoyo_parse_envp(char *left, char *right,
 307                               struct tomoyo_envp *envp)
 308 {
 309         const struct tomoyo_path_info *name;
 310         const struct tomoyo_path_info *value;
 311         char *cp = left + strlen(left) - 1;
 312         if (*cp-- != ']' || *cp != '"')
 313                 goto out;
 314         *cp = '\0';
 315         if (!tomoyo_correct_word(left))
 316                 goto out;
 317         name = tomoyo_get_name(left);
 318         if (!name)
 319                 goto out;
 320         if (!strcmp(right, "NULL")) {
 321                 value = NULL;
 322         } else {
 323                 value = tomoyo_get_dqword(right);
 324                 if (!value) {
 325                         tomoyo_put_name(name);
 326                         goto out;
 327                 }
 328         }
 329         envp->name = name;
 330         envp->value = value;
 331         return true;
 332 out:
 333         return false;
 334 }
 335
 336 /**
 337  * tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry.
 338  *
 339  * @a: Pointer to "struct tomoyo_condition".
 340  * @b: Pointer to "struct tomoyo_condition".
 341  *
 342  * Returns true if @a == @b, false otherwise.
 343  */
 344 static inline bool tomoyo_same_condition(const struct tomoyo_condition *a,
 345                                          const struct tomoyo_condition *b)
 346 {
 347         return a->size == b->size && a->condc == b->condc &&
 348                 a->numbers_count == b->numbers_count &&
 349                 a->names_count == b->names_count &&
 350                 a->argc == b->argc && a->envc == b->envc &&
 351                 a->grant_log == b->grant_log && a->transit == b->transit &&
 352                 !memcmp(a + 1, b + 1, a->size - sizeof(*a));
 353 }
 354
 355 /**
 356  * tomoyo_condition_type - Get condition type.
 357  *
 358  * @word: Keyword string.
 359  *
 360  * Returns one of values in "enum tomoyo_conditions_index" on success,
 361  * TOMOYO_MAX_CONDITION_KEYWORD otherwise.
 362  */
 363 static u8 tomoyo_condition_type(const char *word)
 364 {
 365         u8 i;
 366         for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) {
 367                 if (!strcmp(word, tomoyo_condition_keyword[i]))
 368                         break;
 369         }
 370         return i;
 371 }
 372
 373 /* Define this to enable debug mode. */
 374 /* #define DEBUG_CONDITION */
 375
 376 #ifdef DEBUG_CONDITION
 377 #define dprintk printk
 378 #else
 379 #define dprintk(...) do { } while (0)
 380 #endif
 381
 382 /**
 383  * tomoyo_commit_condition - Commit "struct tomoyo_condition".
 384  *
 385  * @entry: Pointer to "struct tomoyo_condition".
 386  *
 387  * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
 388  *
 389  * This function merges duplicated entries. This function returns NULL if
 390  * @entry is not duplicated but memory quota for policy has exceeded.
 391  */
 392 static struct tomoyo_condition *tomoyo_commit_condition
 393 (struct tomoyo_condition *entry)
 394 {
 395         struct tomoyo_condition *ptr;
 396         bool found = false;
 397         if (mutex_lock_interruptible(&tomoyo_policy_lock)) {
 398                 dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
 399                 ptr = NULL;
 400                 found = true;
 401                 goto out;
 402         }
 403         list_for_each_entry(ptr, &tomoyo_condition_list, head.list) {
 404                 if (!tomoyo_same_condition(ptr, entry) ||
 405                     atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS)
 406                         continue;
 407                 /* Same entry found. Share this entry. */
 408                 atomic_inc(&ptr->head.users);
 409                 found = true;
 410                 break;
 411         }
 412         if (!found) {
 413                 if (tomoyo_memory_ok(entry)) {
 414                         atomic_set(&entry->head.users, 1);
 415                         list_add(&entry->head.list, &tomoyo_condition_list);
 416                 } else {
 417                         found = true;
 418                         ptr = NULL;
 419                 }
 420         }
 421         mutex_unlock(&tomoyo_policy_lock);
 422 out:
 423         if (found) {
 424                 tomoyo_del_condition(&entry->head.list);
 425                 kfree(entry);
 426                 entry = ptr;
 427         }
 428         return entry;
 429 }
 430
 431 /**
 432  * tomoyo_get_transit_preference - Parse domain transition preference for execve().
 433  *
 434  * @param: Pointer to "struct tomoyo_acl_param".
 435  * @e:     Pointer to "struct tomoyo_condition".
 436  *
 437  * Returns the condition string part.
 438  */
 439 static char *tomoyo_get_transit_preference(struct tomoyo_acl_param *param,
 440                                            struct tomoyo_condition *e)
 441 {
 442         char * const pos = param->data;
 443         bool flag;
 444         if (*pos == '<') {
 445                 e->transit = tomoyo_get_domainname(param);
 446                 goto done;
 447         }
 448         {
 449                 char *cp = strchr(pos, ' ');
 450                 if (cp)
 451                         *cp = '\0';
 452                 flag = tomoyo_correct_path(pos) || !strcmp(pos, "keep") ||
 453                         !strcmp(pos, "initialize") || !strcmp(pos, "reset") ||
 454                         !strcmp(pos, "child") || !strcmp(pos, "parent");
 455                 if (cp)
 456                         *cp = ' ';
 457         }
 458         if (!flag)
 459                 return pos;
 460         e->transit = tomoyo_get_name(tomoyo_read_token(param));
 461 done:
 462         if (e->transit)
 463                 return param->data;
 464         /*
 465          * Return a bad read-only condition string that will let
 466          * tomoyo_get_condition() return NULL.
 467          */
 468         return "/";
 469 }
 470
 471 /**
 472  * tomoyo_get_condition - Parse condition part.
 473  *
 474  * @param: Pointer to "struct tomoyo_acl_param".
 475  *
 476  * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
 477  */
 478 struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param)
 479 {
 480         struct tomoyo_condition *entry = NULL;
 481         struct tomoyo_condition_element *condp = NULL;
 482         struct tomoyo_number_union *numbers_p = NULL;
 483         struct tomoyo_name_union *names_p = NULL;
 484         struct tomoyo_argv *argv = NULL;
 485         struct tomoyo_envp *envp = NULL;
 486         struct tomoyo_condition e = { };
 487         char * const start_of_string =
 488                 tomoyo_get_transit_preference(param, &e);
 489         char * const end_of_string = start_of_string + strlen(start_of_string);
 490         char *pos;
 491 rerun:
 492         pos = start_of_string;
 493         while (1) {
 494                 u8 left = -1;
 495                 u8 right = -1;
 496                 char *left_word = pos;
 497                 char *cp;
 498                 char *right_word;
 499                 bool is_not;
 500                 if (!*left_word)
 501                         break;
 502                 /*
 503                  * Since left-hand condition does not allow use of "path_group"
 504                  * or "number_group" and environment variable's names do not
 505                  * accept '=', it is guaranteed that the original line consists
 506                  * of one or more repetition of $left$operator$right blocks
 507                  * where "$left is free from '=' and ' '" and "$operator is
 508                  * either '=' or '!='" and "$right is free from ' '".
 509                  * Therefore, we can reconstruct the original line at the end
 510                  * of dry run even if we overwrite $operator with '\0'.
 511                  */
 512                 cp = strchr(pos, ' ');
 513                 if (cp) {
 514                         *cp = '\0'; /* Will restore later. */
 515                         pos = cp + 1;
 516                 } else {
 517                         pos = "";
 518                 }
 519                 right_word = strchr(left_word, '=');
 520                 if (!right_word || right_word == left_word)
 521                         goto out;
 522                 is_not = *(right_word - 1) == '!';
 523                 if (is_not)
 524                         *(right_word++ - 1) = '\0'; /* Will restore later. */
 525                 else if (*(right_word + 1) != '=')
 526                         *right_word++ = '\0'; /* Will restore later. */
 527                 else
 528                         goto out;
 529                 dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word,
 530                         is_not ? "!" : "", right_word);
 531                 if (!strcmp(left_word, "grant_log")) {
 532                         if (entry) {
 533                                 if (is_not ||
 534                                     entry->grant_log != TOMOYO_GRANTLOG_AUTO)
 535                                         goto out;
 536                                 else if (!strcmp(right_word, "yes"))
 537                                         entry->grant_log = TOMOYO_GRANTLOG_YES;
 538                                 else if (!strcmp(right_word, "no"))
 539                                         entry->grant_log = TOMOYO_GRANTLOG_NO;
 540                                 else
 541                                         goto out;
 542                         }
 543                         continue;
 544                 }
 545                 if (!strncmp(left_word, "exec.argv[", 10)) {
 546                         if (!argv) {
 547                                 e.argc++;
 548                                 e.condc++;
 549                         } else {
 550                                 e.argc--;
 551                                 e.condc--;
 552                                 left = TOMOYO_ARGV_ENTRY;
 553                                 argv->is_not = is_not;
 554                                 if (!tomoyo_parse_argv(left_word + 10,
 555                                                        right_word, argv++))
 556                                         goto out;
 557                         }
 558                         goto store_value;
 559                 }
 560                 if (!strncmp(left_word, "exec.envp[\"", 11)) {
 561                         if (!envp) {
 562                                 e.envc++;
 563                                 e.condc++;
 564                         } else {
 565                                 e.envc--;
 566                                 e.condc--;
 567                                 left = TOMOYO_ENVP_ENTRY;
 568                                 envp->is_not = is_not;
 569                                 if (!tomoyo_parse_envp(left_word + 11,
 570                                                        right_word, envp++))
 571                                         goto out;
 572                         }
 573                         goto store_value;
 574                 }
 575                 left = tomoyo_condition_type(left_word);
 576                 dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word,
 577                         left);
 578                 if (left == TOMOYO_MAX_CONDITION_KEYWORD) {
 579                         if (!numbers_p) {
 580                                 e.numbers_count++;
 581                         } else {
 582                                 e.numbers_count--;
 583                                 left = TOMOYO_NUMBER_UNION;
 584                                 param->data = left_word;
 585                                 if (*left_word == '@' ||
 586                                     !tomoyo_parse_number_union(param,
 587                                                                numbers_p++))
 588                                         goto out;
 589                         }
 590                 }
 591                 if (!condp)
 592                         e.condc++;
 593                 else
 594                         e.condc--;
 595                 if (left == TOMOYO_EXEC_REALPATH ||
 596                     left == TOMOYO_SYMLINK_TARGET) {
 597                         if (!names_p) {
 598                                 e.names_count++;
 599                         } else {
 600                                 e.names_count--;
 601                                 right = TOMOYO_NAME_UNION;
 602                                 param->data = right_word;
 603                                 if (!tomoyo_parse_name_union_quoted(param,
 604                                                                     names_p++))
 605                                         goto out;
 606                         }
 607                         goto store_value;
 608                 }
 609                 right = tomoyo_condition_type(right_word);
 610                 if (right == TOMOYO_MAX_CONDITION_KEYWORD) {
 611                         if (!numbers_p) {
 612                                 e.numbers_count++;
 613                         } else {
 614                                 e.numbers_count--;
 615                                 right = TOMOYO_NUMBER_UNION;
 616                                 param->data = right_word;
 617                                 if (!tomoyo_parse_number_union(param,
 618                                                                numbers_p++))
 619                                         goto out;
 620                         }
 621                 }
 622 store_value:
 623                 if (!condp) {
 624                         dprintk(KERN_WARNING "%u: dry_run left=%u right=%u "
 625                                 "match=%u\n", __LINE__, left, right, !is_not);
 626                         continue;
 627                 }
 628                 condp->left = left;
 629                 condp->right = right;
 630                 condp->equals = !is_not;
 631                 dprintk(KERN_WARNING "%u: left=%u right=%u match=%u\n",
 632                         __LINE__, condp->left, condp->right,
 633                         condp->equals);
 634                 condp++;
 635         }
 636         dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u ac=%u ec=%u\n",
 637                 __LINE__, e.condc, e.numbers_count, e.names_count, e.argc,
 638                 e.envc);
 639         if (entry) {
 640                 BUG_ON(e.names_count | e.numbers_count | e.argc | e.envc |
 641                        e.condc);
 642                 return tomoyo_commit_condition(entry);
 643         }
 644         e.size = sizeof(*entry)
 645                 + e.condc * sizeof(struct tomoyo_condition_element)
 646                 + e.numbers_count * sizeof(struct tomoyo_number_union)
 647                 + e.names_count * sizeof(struct tomoyo_name_union)
 648                 + e.argc * sizeof(struct tomoyo_argv)
 649                 + e.envc * sizeof(struct tomoyo_envp);
 650         entry = kzalloc(e.size, GFP_NOFS);
 651         if (!entry)
 652                 goto out2;
 653         *entry = e;
 654         e.transit = NULL;
 655         condp = (struct tomoyo_condition_element *) (entry + 1);
 656         numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
 657         names_p = (struct tomoyo_name_union *) (numbers_p + e.numbers_count);
 658         argv = (struct tomoyo_argv *) (names_p + e.names_count);
 659         envp = (struct tomoyo_envp *) (argv + e.argc);
 660         {
 661                 bool flag = false;
 662                 for (pos = start_of_string; pos < end_of_string; pos++) {
 663                         if (*pos)
 664                                 continue;
 665                         if (flag) /* Restore " ". */
 666                                 *pos = ' ';
 667                         else if (*(pos + 1) == '=') /* Restore "!=". */
 668                                 *pos = '!';
 669                         else /* Restore "=". */
 670                                 *pos = '=';
 671                         flag = !flag;
 672                 }
 673         }
 674         goto rerun;
 675 out:
 676         dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
 677         if (entry) {
 678                 tomoyo_del_condition(&entry->head.list);
 679                 kfree(entry);
 680         }
 681 out2:
 682         tomoyo_put_name(e.transit);
 683         return NULL;
 684 }
 685
 686 /**
 687  * tomoyo_get_attributes - Revalidate "struct inode".
 688  *
 689  * @obj: Pointer to "struct tomoyo_obj_info".
 690  *
 691  * Returns nothing.
 692  */
 693 void tomoyo_get_attributes(struct tomoyo_obj_info *obj)
 694 {
 695         u8 i;
 696         struct dentry *dentry = NULL;
 697
 698         for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
 699                 struct inode *inode;
 700                 switch (i) {
 701                 case TOMOYO_PATH1:
 702                         dentry = obj->path1.dentry;
 703                         if (!dentry)
 704                                 continue;
 705                         break;
 706                 case TOMOYO_PATH2:
 707                         dentry = obj->path2.dentry;
 708                         if (!dentry)
 709                                 continue;
 710                         break;
 711                 default:
 712                         if (!dentry)
 713                                 continue;
 714                         dentry = dget_parent(dentry);
 715                         break;
 716                 }
 717                 inode = dentry->d_inode;
 718                 if (inode) {
 719                         struct tomoyo_mini_stat *stat = &obj->stat[i];
 720                         stat->uid  = inode->i_uid;
 721                         stat->gid  = inode->i_gid;
 722                         stat->ino  = inode->i_ino;
 723                         stat->mode = inode->i_mode;
 724                         stat->dev  = inode->i_sb->s_dev;
 725                         stat->rdev = inode->i_rdev;
 726                         obj->stat_valid[i] = true;
 727                 }
 728                 if (i & 1) /* i == TOMOYO_PATH1_PARENT ||
 729                               i == TOMOYO_PATH2_PARENT */
 730                         dput(dentry);
 731         }
 732 }
 733
 734 /**
 735  * tomoyo_condition - Check condition part.
 736  *
 737  * @r:    Pointer to "struct tomoyo_request_info".
 738  * @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
 739  *
 740  * Returns true on success, false otherwise.
 741  *
 742  * Caller holds tomoyo_read_lock().
 743  */
 744 bool tomoyo_condition(struct tomoyo_request_info *r,
 745                       const struct tomoyo_condition *cond)
 746 {
 747         u32 i;
 748         unsigned long min_v[2] = { 0, 0 };
 749         unsigned long max_v[2] = { 0, 0 };
 750         const struct tomoyo_condition_element *condp;
 751         const struct tomoyo_number_union *numbers_p;
 752         const struct tomoyo_name_union *names_p;
 753         const struct tomoyo_argv *argv;
 754         const struct tomoyo_envp *envp;
 755         struct tomoyo_obj_info *obj;
 756         u16 condc;
 757         u16 argc;
 758         u16 envc;
 759         struct linux_binprm *bprm = NULL;
 760         if (!cond)
 761                 return true;
 762         condc = cond->condc;
 763         argc = cond->argc;
 764         envc = cond->envc;
 765         obj = r->obj;
 766         if (r->ee)
 767                 bprm = r->ee->bprm;
 768         if (!bprm && (argc || envc))
 769                 return false;
 770         condp = (struct tomoyo_condition_element *) (cond + 1);
 771         numbers_p = (const struct tomoyo_number_union *) (condp + condc);
 772         names_p = (const struct tomoyo_name_union *)
 773                 (numbers_p + cond->numbers_count);
 774         argv = (const struct tomoyo_argv *) (names_p + cond->names_count);
 775         envp = (const struct tomoyo_envp *) (argv + argc);
 776         for (i = 0; i < condc; i++) {
 777                 const bool match = condp->equals;
 778                 const u8 left = condp->left;
 779                 const u8 right = condp->right;
 780                 bool is_bitop[2] = { false, false };
 781                 u8 j;
 782                 condp++;
 783                 /* Check argv[] and envp[] later. */
 784                 if (left == TOMOYO_ARGV_ENTRY || left == TOMOYO_ENVP_ENTRY)
 785                         continue;
 786                 /* Check string expressions. */
 787                 if (right == TOMOYO_NAME_UNION) {
 788                         const struct tomoyo_name_union *ptr = names_p++;
 789                         switch (left) {
 790                                 struct tomoyo_path_info *symlink;
 791                                 struct tomoyo_execve *ee;
 792                                 struct file *file;
 793                         case TOMOYO_SYMLINK_TARGET:
 794                                 symlink = obj ? obj->symlink_target : NULL;
 795                                 if (!symlink ||
 796                                     !tomoyo_compare_name_union(symlink, ptr)
 797                                     == match)
 798                                         goto out;
 799                                 break;
 800                         case TOMOYO_EXEC_REALPATH:
 801                                 ee = r->ee;
 802                                 file = ee ? ee->bprm->file : NULL;
 803                                 if (!tomoyo_scan_exec_realpath(file, ptr,
 804                                                                match))
 805                                         goto out;
 806                                 break;
 807                         }
 808                         continue;
 809                 }
 810                 /* Check numeric or bit-op expressions. */
 811                 for (j = 0; j < 2; j++) {
 812                         const u8 index = j ? right : left;
 813                         unsigned long value = 0;
 814                         switch (index) {
 815                         case TOMOYO_TASK_UID:
 816                                 value = current_uid();
 817                                 break;
 818                         case TOMOYO_TASK_EUID:
 819                                 value = current_euid();
 820                                 break;
 821                         case TOMOYO_TASK_SUID:
 822                                 value = current_suid();
 823                                 break;
 824                         case TOMOYO_TASK_FSUID:
 825                                 value = current_fsuid();
 826                                 break;
 827                         case TOMOYO_TASK_GID:
 828                                 value = current_gid();
 829                                 break;
 830                         case TOMOYO_TASK_EGID:
 831                                 value = current_egid();
 832                                 break;
 833                         case TOMOYO_TASK_SGID:
 834                                 value = current_sgid();
 835                                 break;
 836                         case TOMOYO_TASK_FSGID:
 837                                 value = current_fsgid();
 838                                 break;
 839                         case TOMOYO_TASK_PID:
 840                                 value = tomoyo_sys_getpid();
 841                                 break;
 842                         case TOMOYO_TASK_PPID:
 843                                 value = tomoyo_sys_getppid();
 844                                 break;
 845                         case TOMOYO_TYPE_IS_SOCKET:
 846                                 value = S_IFSOCK;
 847                                 break;
 848                         case TOMOYO_TYPE_IS_SYMLINK:
 849                                 value = S_IFLNK;
 850                                 break;
 851                         case TOMOYO_TYPE_IS_FILE:
 852                                 value = S_IFREG;
 853                                 break;
 854                         case TOMOYO_TYPE_IS_BLOCK_DEV:
 855                                 value = S_IFBLK;
 856                                 break;
 857                         case TOMOYO_TYPE_IS_DIRECTORY:
 858                                 value = S_IFDIR;
 859                                 break;
 860                         case TOMOYO_TYPE_IS_CHAR_DEV:
 861                                 value = S_IFCHR;
 862                                 break;
 863                         case TOMOYO_TYPE_IS_FIFO:
 864                                 value = S_IFIFO;
 865                                 break;
 866                         case TOMOYO_MODE_SETUID:
 867                                 value = S_ISUID;
 868                                 break;
 869                         case TOMOYO_MODE_SETGID:
 870                                 value = S_ISGID;
 871                                 break;
 872                         case TOMOYO_MODE_STICKY:
 873                                 value = S_ISVTX;
 874                                 break;
 875                         case TOMOYO_MODE_OWNER_READ:
 876                                 value = S_IRUSR;
 877                                 break;
 878                         case TOMOYO_MODE_OWNER_WRITE:
 879                                 value = S_IWUSR;
 880                                 break;
 881                         case TOMOYO_MODE_OWNER_EXECUTE:
 882                                 value = S_IXUSR;
 883                                 break;
 884                         case TOMOYO_MODE_GROUP_READ:
 885                                 value = S_IRGRP;
 886                                 break;
 887                         case TOMOYO_MODE_GROUP_WRITE:
 888                                 value = S_IWGRP;
 889                                 break;
 890                         case TOMOYO_MODE_GROUP_EXECUTE:
 891                                 value = S_IXGRP;
 892                                 break;
 893                         case TOMOYO_MODE_OTHERS_READ:
 894                                 value = S_IROTH;
 895                                 break;
 896                         case TOMOYO_MODE_OTHERS_WRITE:
 897                                 value = S_IWOTH;
 898                                 break;
 899                         case TOMOYO_MODE_OTHERS_EXECUTE:
 900                                 value = S_IXOTH;
 901                                 break;
 902                         case TOMOYO_EXEC_ARGC:
 903                                 if (!bprm)
 904                                         goto out;
 905                                 value = bprm->argc;
 906                                 break;
 907                         case TOMOYO_EXEC_ENVC:
 908                                 if (!bprm)
 909                                         goto out;
 910                                 value = bprm->envc;
 911                                 break;
 912                         case TOMOYO_NUMBER_UNION:
 913                                 /* Fetch values later. */
 914                                 break;
 915                         default:
 916                                 if (!obj)
 917                                         goto out;
 918                                 if (!obj->validate_done) {
 919                                         tomoyo_get_attributes(obj);
 920                                         obj->validate_done = true;
 921                                 }
 922                                 {
 923                                         u8 stat_index;
 924                                         struct tomoyo_mini_stat *stat;
 925                                         switch (index) {
 926                                         case TOMOYO_PATH1_UID:
 927                                         case TOMOYO_PATH1_GID:
 928                                         case TOMOYO_PATH1_INO:
 929                                         case TOMOYO_PATH1_MAJOR:
 930                                         case TOMOYO_PATH1_MINOR:
 931                                         case TOMOYO_PATH1_TYPE:
 932                                         case TOMOYO_PATH1_DEV_MAJOR:
 933                                         case TOMOYO_PATH1_DEV_MINOR:
 934                                         case TOMOYO_PATH1_PERM:
 935                                                 stat_index = TOMOYO_PATH1;
 936                                                 break;
 937                                         case TOMOYO_PATH2_UID:
 938                                         case TOMOYO_PATH2_GID:
 939                                         case TOMOYO_PATH2_INO:
 940                                         case TOMOYO_PATH2_MAJOR:
 941                                         case TOMOYO_PATH2_MINOR:
 942                                         case TOMOYO_PATH2_TYPE:
 943                                         case TOMOYO_PATH2_DEV_MAJOR:
 944                                         case TOMOYO_PATH2_DEV_MINOR:
 945                                         case TOMOYO_PATH2_PERM:
 946                                                 stat_index = TOMOYO_PATH2;
 947                                                 break;
 948                                         case TOMOYO_PATH1_PARENT_UID:
 949                                         case TOMOYO_PATH1_PARENT_GID:
 950                                         case TOMOYO_PATH1_PARENT_INO:
 951                                         case TOMOYO_PATH1_PARENT_PERM:
 952                                                 stat_index =
 953                                                         TOMOYO_PATH1_PARENT;
 954                                                 break;
 955                                         case TOMOYO_PATH2_PARENT_UID:
 956                                         case TOMOYO_PATH2_PARENT_GID:
 957                                         case TOMOYO_PATH2_PARENT_INO:
 958                                         case TOMOYO_PATH2_PARENT_PERM:
 959                                                 stat_index =
 960                                                         TOMOYO_PATH2_PARENT;
 961                                                 break;
 962                                         default:
 963                                                 goto out;
 964                                         }
 965                                         if (!obj->stat_valid[stat_index])
 966                                                 goto out;
 967                                         stat = &obj->stat[stat_index];
 968                                         switch (index) {
 969                                         case TOMOYO_PATH1_UID:
 970                                         case TOMOYO_PATH2_UID:
 971                                         case TOMOYO_PATH1_PARENT_UID:
 972                                         case TOMOYO_PATH2_PARENT_UID:
 973                                                 value = stat->uid;
 974                                                 break;
 975                                         case TOMOYO_PATH1_GID:
 976                                         case TOMOYO_PATH2_GID:
 977                                         case TOMOYO_PATH1_PARENT_GID:
 978                                         case TOMOYO_PATH2_PARENT_GID:
 979                                                 value = stat->gid;
 980                                                 break;
 981                                         case TOMOYO_PATH1_INO:
 982                                         case TOMOYO_PATH2_INO:
 983                                         case TOMOYO_PATH1_PARENT_INO:
 984                                         case TOMOYO_PATH2_PARENT_INO:
 985                                                 value = stat->ino;
 986                                                 break;
 987                                         case TOMOYO_PATH1_MAJOR:
 988                                         case TOMOYO_PATH2_MAJOR:
 989                                                 value = MAJOR(stat->dev);
 990                                                 break;
 991                                         case TOMOYO_PATH1_MINOR:
 992                                         case TOMOYO_PATH2_MINOR:
 993                                                 value = MINOR(stat->dev);
 994                                                 break;
 995                                         case TOMOYO_PATH1_TYPE:
 996                                         case TOMOYO_PATH2_TYPE:
 997                                                 value = stat->mode & S_IFMT;
 998                                                 break;
 999                                         case TOMOYO_PATH1_DEV_MAJOR:
1000                                         case TOMOYO_PATH2_DEV_MAJOR:
1001                                                 value = MAJOR(stat->rdev);
1002                                                 break;
1003                                         case TOMOYO_PATH1_DEV_MINOR:
1004                                         case TOMOYO_PATH2_DEV_MINOR:
1005                                                 value = MINOR(stat->rdev);
1006                                                 break;
1007                                         case TOMOYO_PATH1_PERM:
1008                                         case TOMOYO_PATH2_PERM:
1009                                         case TOMOYO_PATH1_PARENT_PERM:
1010                                         case TOMOYO_PATH2_PARENT_PERM:
1011                                                 value = stat->mode & S_IALLUGO;
1012                                                 break;
1013                                         }
1014                                 }
1015                                 break;
1016                         }
1017                         max_v[j] = value;
1018                         min_v[j] = value;
1019                         switch (index) {
1020                         case TOMOYO_MODE_SETUID:
1021                         case TOMOYO_MODE_SETGID:
1022                         case TOMOYO_MODE_STICKY:
1023                         case TOMOYO_MODE_OWNER_READ:
1024                         case TOMOYO_MODE_OWNER_WRITE:
1025                         case TOMOYO_MODE_OWNER_EXECUTE:
1026                         case TOMOYO_MODE_GROUP_READ:
1027                         case TOMOYO_MODE_GROUP_WRITE:
1028                         case TOMOYO_MODE_GROUP_EXECUTE:
1029                         case TOMOYO_MODE_OTHERS_READ:
1030                         case TOMOYO_MODE_OTHERS_WRITE:
1031                         case TOMOYO_MODE_OTHERS_EXECUTE:
1032                                 is_bitop[j] = true;
1033                         }
1034                 }
1035                 if (left == TOMOYO_NUMBER_UNION) {
1036                         /* Fetch values now. */
1037                         const struct tomoyo_number_union *ptr = numbers_p++;
1038                         min_v[0] = ptr->values[0];
1039                         max_v[0] = ptr->values[1];
1040                 }
1041                 if (right == TOMOYO_NUMBER_UNION) {
1042                         /* Fetch values now. */
1043                         const struct tomoyo_number_union *ptr = numbers_p++;
1044                         if (ptr->group) {
1045                                 if (tomoyo_number_matches_group(min_v[0],
1046                                                                 max_v[0],
1047                                                                 ptr->group)
1048                                     == match)
1049                                         continue;
1050                         } else {
1051                                 if ((min_v[0] <= ptr->values[1] &&
1052                                      max_v[0] >= ptr->values[0]) == match)
1053                                         continue;
1054                         }
1055                         goto out;
1056                 }
1057                 /*
1058                  * Bit operation is valid only when counterpart value
1059                  * represents permission.
1060                  */
1061                 if (is_bitop[0] && is_bitop[1]) {
1062                         goto out;
1063                 } else if (is_bitop[0]) {
1064                         switch (right) {
1065                         case TOMOYO_PATH1_PERM:
1066                         case TOMOYO_PATH1_PARENT_PERM:
1067                         case TOMOYO_PATH2_PERM:
1068                         case TOMOYO_PATH2_PARENT_PERM:
1069                                 if (!(max_v[0] & max_v[1]) == !match)
1070                                         continue;
1071                         }
1072                         goto out;
1073                 } else if (is_bitop[1]) {
1074                         switch (left) {
1075                         case TOMOYO_PATH1_PERM:
1076                         case TOMOYO_PATH1_PARENT_PERM:
1077                         case TOMOYO_PATH2_PERM:
1078                         case TOMOYO_PATH2_PARENT_PERM:
1079                                 if (!(max_v[0] & max_v[1]) == !match)
1080                                         continue;
1081                         }
1082                         goto out;
1083                 }
1084                 /* Normal value range comparison. */
1085                 if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
1086                         continue;
1087 out:
1088                 return false;
1089         }
1090         /* Check argv[] and envp[] now. */
1091         if (r->ee && (argc || envc))
1092                 return tomoyo_scan_bprm(r->ee, argc, argv, envc, envp);
1093         return true;
1094 }