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                 !memcmp(a + 1, b + 1, a->size - sizeof(*a));
 352 }
 353
 354 /**
 355  * tomoyo_condition_type - Get condition type.
 356  *
 357  * @word: Keyword string.
 358  *
 359  * Returns one of values in "enum tomoyo_conditions_index" on success,
 360  * TOMOYO_MAX_CONDITION_KEYWORD otherwise.
 361  */
 362 static u8 tomoyo_condition_type(const char *word)
 363 {
 364         u8 i;
 365         for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) {
 366                 if (!strcmp(word, tomoyo_condition_keyword[i]))
 367                         break;
 368         }
 369         return i;
 370 }
 371
 372 /* Define this to enable debug mode. */
 373 /* #define DEBUG_CONDITION */
 374
 375 #ifdef DEBUG_CONDITION
 376 #define dprintk printk
 377 #else
 378 #define dprintk(...) do { } while (0)
 379 #endif
 380
 381 /**
 382  * tomoyo_commit_condition - Commit "struct tomoyo_condition".
 383  *
 384  * @entry: Pointer to "struct tomoyo_condition".
 385  *
 386  * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
 387  *
 388  * This function merges duplicated entries. This function returns NULL if
 389  * @entry is not duplicated but memory quota for policy has exceeded.
 390  */
 391 static struct tomoyo_condition *tomoyo_commit_condition
 392 (struct tomoyo_condition *entry)
 393 {
 394         struct tomoyo_condition *ptr;
 395         bool found = false;
 396         if (mutex_lock_interruptible(&tomoyo_policy_lock)) {
 397                 dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
 398                 ptr = NULL;
 399                 found = true;
 400                 goto out;
 401         }
 402         list_for_each_entry_rcu(ptr, &tomoyo_condition_list, head.list) {
 403                 if (!tomoyo_same_condition(ptr, entry))
 404                         continue;
 405                 /* Same entry found. Share this entry. */
 406                 atomic_inc(&ptr->head.users);
 407                 found = true;
 408                 break;
 409         }
 410         if (!found) {
 411                 if (tomoyo_memory_ok(entry)) {
 412                         atomic_set(&entry->head.users, 1);
 413                         list_add_rcu(&entry->head.list,
 414                                      &tomoyo_condition_list);
 415                 } else {
 416                         found = true;
 417                         ptr = NULL;
 418                 }
 419         }
 420         mutex_unlock(&tomoyo_policy_lock);
 421 out:
 422         if (found) {
 423                 tomoyo_del_condition(&entry->head.list);
 424                 kfree(entry);
 425                 entry = ptr;
 426         }
 427         return entry;
 428 }
 429
 430 /**
 431  * tomoyo_get_condition - Parse condition part.
 432  *
 433  * @param: Pointer to "struct tomoyo_acl_param".
 434  *
 435  * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
 436  */
 437 struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param)
 438 {
 439         struct tomoyo_condition *entry = NULL;
 440         struct tomoyo_condition_element *condp = NULL;
 441         struct tomoyo_number_union *numbers_p = NULL;
 442         struct tomoyo_name_union *names_p = NULL;
 443         struct tomoyo_argv *argv = NULL;
 444         struct tomoyo_envp *envp = NULL;
 445         struct tomoyo_condition e = { };
 446         char * const start_of_string = param->data;
 447         char * const end_of_string = start_of_string + strlen(start_of_string);
 448         char *pos;
 449 rerun:
 450         pos = start_of_string;
 451         while (1) {
 452                 u8 left = -1;
 453                 u8 right = -1;
 454                 char *left_word = pos;
 455                 char *cp;
 456                 char *right_word;
 457                 bool is_not;
 458                 if (!*left_word)
 459                         break;
 460                 /*
 461                  * Since left-hand condition does not allow use of "path_group"
 462                  * or "number_group" and environment variable's names do not
 463                  * accept '=', it is guaranteed that the original line consists
 464                  * of one or more repetition of $left$operator$right blocks
 465                  * where "$left is free from '=' and ' '" and "$operator is
 466                  * either '=' or '!='" and "$right is free from ' '".
 467                  * Therefore, we can reconstruct the original line at the end
 468                  * of dry run even if we overwrite $operator with '\0'.
 469                  */
 470                 cp = strchr(pos, ' ');
 471                 if (cp) {
 472                         *cp = '\0'; /* Will restore later. */
 473                         pos = cp + 1;
 474                 } else {
 475                         pos = "";
 476                 }
 477                 right_word = strchr(left_word, '=');
 478                 if (!right_word || right_word == left_word)
 479                         goto out;
 480                 is_not = *(right_word - 1) == '!';
 481                 if (is_not)
 482                         *(right_word++ - 1) = '\0'; /* Will restore later. */
 483                 else if (*(right_word + 1) != '=')
 484                         *right_word++ = '\0'; /* Will restore later. */
 485                 else
 486                         goto out;
 487                 dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word,
 488                         is_not ? "!" : "", right_word);
 489                 if (!strncmp(left_word, "exec.argv[", 10)) {
 490                         if (!argv) {
 491                                 e.argc++;
 492                                 e.condc++;
 493                         } else {
 494                                 e.argc--;
 495                                 e.condc--;
 496                                 left = TOMOYO_ARGV_ENTRY;
 497                                 argv->is_not = is_not;
 498                                 if (!tomoyo_parse_argv(left_word + 10,
 499                                                        right_word, argv++))
 500                                         goto out;
 501                         }
 502                         goto store_value;
 503                 }
 504                 if (!strncmp(left_word, "exec.envp[\"", 11)) {
 505                         if (!envp) {
 506                                 e.envc++;
 507                                 e.condc++;
 508                         } else {
 509                                 e.envc--;
 510                                 e.condc--;
 511                                 left = TOMOYO_ENVP_ENTRY;
 512                                 envp->is_not = is_not;
 513                                 if (!tomoyo_parse_envp(left_word + 11,
 514                                                        right_word, envp++))
 515                                         goto out;
 516                         }
 517                         goto store_value;
 518                 }
 519                 left = tomoyo_condition_type(left_word);
 520                 dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word,
 521                         left);
 522                 if (left == TOMOYO_MAX_CONDITION_KEYWORD) {
 523                         if (!numbers_p) {
 524                                 e.numbers_count++;
 525                         } else {
 526                                 e.numbers_count--;
 527                                 left = TOMOYO_NUMBER_UNION;
 528                                 param->data = left_word;
 529                                 if (*left_word == '@' ||
 530                                     !tomoyo_parse_number_union(param,
 531                                                                numbers_p++))
 532                                         goto out;
 533                         }
 534                 }
 535                 if (!condp)
 536                         e.condc++;
 537                 else
 538                         e.condc--;
 539                 if (left == TOMOYO_EXEC_REALPATH ||
 540                     left == TOMOYO_SYMLINK_TARGET) {
 541                         if (!names_p) {
 542                                 e.names_count++;
 543                         } else {
 544                                 e.names_count--;
 545                                 right = TOMOYO_NAME_UNION;
 546                                 param->data = right_word;
 547                                 if (!tomoyo_parse_name_union_quoted(param,
 548                                                                     names_p++))
 549                                         goto out;
 550                         }
 551                         goto store_value;
 552                 }
 553                 right = tomoyo_condition_type(right_word);
 554                 if (right == TOMOYO_MAX_CONDITION_KEYWORD) {
 555                         if (!numbers_p) {
 556                                 e.numbers_count++;
 557                         } else {
 558                                 e.numbers_count--;
 559                                 right = TOMOYO_NUMBER_UNION;
 560                                 param->data = right_word;
 561                                 if (!tomoyo_parse_number_union(param,
 562                                                                numbers_p++))
 563                                         goto out;
 564                         }
 565                 }
 566 store_value:
 567                 if (!condp) {
 568                         dprintk(KERN_WARNING "%u: dry_run left=%u right=%u "
 569                                 "match=%u\n", __LINE__, left, right, !is_not);
 570                         continue;
 571                 }
 572                 condp->left = left;
 573                 condp->right = right;
 574                 condp->equals = !is_not;
 575                 dprintk(KERN_WARNING "%u: left=%u right=%u match=%u\n",
 576                         __LINE__, condp->left, condp->right,
 577                         condp->equals);
 578                 condp++;
 579         }
 580         dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u ac=%u ec=%u\n",
 581                 __LINE__, e.condc, e.numbers_count, e.names_count, e.argc,
 582                 e.envc);
 583         if (entry) {
 584                 BUG_ON(e.names_count | e.numbers_count | e.argc | e.envc |
 585                        e.condc);
 586                 return tomoyo_commit_condition(entry);
 587         }
 588         e.size = sizeof(*entry)
 589                 + e.condc * sizeof(struct tomoyo_condition_element)
 590                 + e.numbers_count * sizeof(struct tomoyo_number_union)
 591                 + e.names_count * sizeof(struct tomoyo_name_union)
 592                 + e.argc * sizeof(struct tomoyo_argv)
 593                 + e.envc * sizeof(struct tomoyo_envp);
 594         entry = kzalloc(e.size, GFP_NOFS);
 595         if (!entry)
 596                 return NULL;
 597         *entry = e;
 598         condp = (struct tomoyo_condition_element *) (entry + 1);
 599         numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
 600         names_p = (struct tomoyo_name_union *) (numbers_p + e.numbers_count);
 601         argv = (struct tomoyo_argv *) (names_p + e.names_count);
 602         envp = (struct tomoyo_envp *) (argv + e.argc);
 603         {
 604                 bool flag = false;
 605                 for (pos = start_of_string; pos < end_of_string; pos++) {
 606                         if (*pos)
 607                                 continue;
 608                         if (flag) /* Restore " ". */
 609                                 *pos = ' ';
 610                         else if (*(pos + 1) == '=') /* Restore "!=". */
 611                                 *pos = '!';
 612                         else /* Restore "=". */
 613                                 *pos = '=';
 614                         flag = !flag;
 615                 }
 616         }
 617         goto rerun;
 618 out:
 619         dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
 620         if (entry) {
 621                 tomoyo_del_condition(&entry->head.list);
 622                 kfree(entry);
 623         }
 624         return NULL;
 625 }
 626
 627 /**
 628  * tomoyo_get_attributes - Revalidate "struct inode".
 629  *
 630  * @obj: Pointer to "struct tomoyo_obj_info".
 631  *
 632  * Returns nothing.
 633  */
 634 void tomoyo_get_attributes(struct tomoyo_obj_info *obj)
 635 {
 636         u8 i;
 637         struct dentry *dentry = NULL;
 638
 639         for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
 640                 struct inode *inode;
 641                 switch (i) {
 642                 case TOMOYO_PATH1:
 643                         dentry = obj->path1.dentry;
 644                         if (!dentry)
 645                                 continue;
 646                         break;
 647                 case TOMOYO_PATH2:
 648                         dentry = obj->path2.dentry;
 649                         if (!dentry)
 650                                 continue;
 651                         break;
 652                 default:
 653                         if (!dentry)
 654                                 continue;
 655                         dentry = dget_parent(dentry);
 656                         break;
 657                 }
 658                 inode = dentry->d_inode;
 659                 if (inode) {
 660                         struct tomoyo_mini_stat *stat = &obj->stat[i];
 661                         stat->uid  = inode->i_uid;
 662                         stat->gid  = inode->i_gid;
 663                         stat->ino  = inode->i_ino;
 664                         stat->mode = inode->i_mode;
 665                         stat->dev  = inode->i_sb->s_dev;
 666                         stat->rdev = inode->i_rdev;
 667                         obj->stat_valid[i] = true;
 668                 }
 669                 if (i & 1) /* i == TOMOYO_PATH1_PARENT ||
 670                               i == TOMOYO_PATH2_PARENT */
 671                         dput(dentry);
 672         }
 673 }
 674
 675 /**
 676  * tomoyo_condition - Check condition part.
 677  *
 678  * @r:    Pointer to "struct tomoyo_request_info".
 679  * @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
 680  *
 681  * Returns true on success, false otherwise.
 682  *
 683  * Caller holds tomoyo_read_lock().
 684  */
 685 bool tomoyo_condition(struct tomoyo_request_info *r,
 686                       const struct tomoyo_condition *cond)
 687 {
 688         u32 i;
 689         unsigned long min_v[2] = { 0, 0 };
 690         unsigned long max_v[2] = { 0, 0 };
 691         const struct tomoyo_condition_element *condp;
 692         const struct tomoyo_number_union *numbers_p;
 693         const struct tomoyo_name_union *names_p;
 694         const struct tomoyo_argv *argv;
 695         const struct tomoyo_envp *envp;
 696         struct tomoyo_obj_info *obj;
 697         u16 condc;
 698         u16 argc;
 699         u16 envc;
 700         struct linux_binprm *bprm = NULL;
 701         if (!cond)
 702                 return true;
 703         condc = cond->condc;
 704         argc = cond->argc;
 705         envc = cond->envc;
 706         obj = r->obj;
 707         if (r->ee)
 708                 bprm = r->ee->bprm;
 709         if (!bprm && (argc || envc))
 710                 return false;
 711         condp = (struct tomoyo_condition_element *) (cond + 1);
 712         numbers_p = (const struct tomoyo_number_union *) (condp + condc);
 713         names_p = (const struct tomoyo_name_union *)
 714                 (numbers_p + cond->numbers_count);
 715         argv = (const struct tomoyo_argv *) (names_p + cond->names_count);
 716         envp = (const struct tomoyo_envp *) (argv + argc);
 717         for (i = 0; i < condc; i++) {
 718                 const bool match = condp->equals;
 719                 const u8 left = condp->left;
 720                 const u8 right = condp->right;
 721                 bool is_bitop[2] = { false, false };
 722                 u8 j;
 723                 condp++;
 724                 /* Check argv[] and envp[] later. */
 725                 if (left == TOMOYO_ARGV_ENTRY || left == TOMOYO_ENVP_ENTRY)
 726                         continue;
 727                 /* Check string expressions. */
 728                 if (right == TOMOYO_NAME_UNION) {
 729                         const struct tomoyo_name_union *ptr = names_p++;
 730                         switch (left) {
 731                                 struct tomoyo_path_info *symlink;
 732                                 struct tomoyo_execve *ee;
 733                                 struct file *file;
 734                         case TOMOYO_SYMLINK_TARGET:
 735                                 symlink = obj ? obj->symlink_target : NULL;
 736                                 if (!symlink ||
 737                                     !tomoyo_compare_name_union(symlink, ptr)
 738                                     == match)
 739                                         goto out;
 740                                 break;
 741                         case TOMOYO_EXEC_REALPATH:
 742                                 ee = r->ee;
 743                                 file = ee ? ee->bprm->file : NULL;
 744                                 if (!tomoyo_scan_exec_realpath(file, ptr,
 745                                                                match))
 746                                         goto out;
 747                                 break;
 748                         }
 749                         continue;
 750                 }
 751                 /* Check numeric or bit-op expressions. */
 752                 for (j = 0; j < 2; j++) {
 753                         const u8 index = j ? right : left;
 754                         unsigned long value = 0;
 755                         switch (index) {
 756                         case TOMOYO_TASK_UID:
 757                                 value = current_uid();
 758                                 break;
 759                         case TOMOYO_TASK_EUID:
 760                                 value = current_euid();
 761                                 break;
 762                         case TOMOYO_TASK_SUID:
 763                                 value = current_suid();
 764                                 break;
 765                         case TOMOYO_TASK_FSUID:
 766                                 value = current_fsuid();
 767                                 break;
 768                         case TOMOYO_TASK_GID:
 769                                 value = current_gid();
 770                                 break;
 771                         case TOMOYO_TASK_EGID:
 772                                 value = current_egid();
 773                                 break;
 774                         case TOMOYO_TASK_SGID:
 775                                 value = current_sgid();
 776                                 break;
 777                         case TOMOYO_TASK_FSGID:
 778                                 value = current_fsgid();
 779                                 break;
 780                         case TOMOYO_TASK_PID:
 781                                 value = tomoyo_sys_getpid();
 782                                 break;
 783                         case TOMOYO_TASK_PPID:
 784                                 value = tomoyo_sys_getppid();
 785                                 break;
 786                         case TOMOYO_TYPE_IS_SOCKET:
 787                                 value = S_IFSOCK;
 788                                 break;
 789                         case TOMOYO_TYPE_IS_SYMLINK:
 790                                 value = S_IFLNK;
 791                                 break;
 792                         case TOMOYO_TYPE_IS_FILE:
 793                                 value = S_IFREG;
 794                                 break;
 795                         case TOMOYO_TYPE_IS_BLOCK_DEV:
 796                                 value = S_IFBLK;
 797                                 break;
 798                         case TOMOYO_TYPE_IS_DIRECTORY:
 799                                 value = S_IFDIR;
 800                                 break;
 801                         case TOMOYO_TYPE_IS_CHAR_DEV:
 802                                 value = S_IFCHR;
 803                                 break;
 804                         case TOMOYO_TYPE_IS_FIFO:
 805                                 value = S_IFIFO;
 806                                 break;
 807                         case TOMOYO_MODE_SETUID:
 808                                 value = S_ISUID;
 809                                 break;
 810                         case TOMOYO_MODE_SETGID:
 811                                 value = S_ISGID;
 812                                 break;
 813                         case TOMOYO_MODE_STICKY:
 814                                 value = S_ISVTX;
 815                                 break;
 816                         case TOMOYO_MODE_OWNER_READ:
 817                                 value = S_IRUSR;
 818                                 break;
 819                         case TOMOYO_MODE_OWNER_WRITE:
 820                                 value = S_IWUSR;
 821                                 break;
 822                         case TOMOYO_MODE_OWNER_EXECUTE:
 823                                 value = S_IXUSR;
 824                                 break;
 825                         case TOMOYO_MODE_GROUP_READ:
 826                                 value = S_IRGRP;
 827                                 break;
 828                         case TOMOYO_MODE_GROUP_WRITE:
 829                                 value = S_IWGRP;
 830                                 break;
 831                         case TOMOYO_MODE_GROUP_EXECUTE:
 832                                 value = S_IXGRP;
 833                                 break;
 834                         case TOMOYO_MODE_OTHERS_READ:
 835                                 value = S_IROTH;
 836                                 break;
 837                         case TOMOYO_MODE_OTHERS_WRITE:
 838                                 value = S_IWOTH;
 839                                 break;
 840                         case TOMOYO_MODE_OTHERS_EXECUTE:
 841                                 value = S_IXOTH;
 842                                 break;
 843                         case TOMOYO_EXEC_ARGC:
 844                                 if (!bprm)
 845                                         goto out;
 846                                 value = bprm->argc;
 847                                 break;
 848                         case TOMOYO_EXEC_ENVC:
 849                                 if (!bprm)
 850                                         goto out;
 851                                 value = bprm->envc;
 852                                 break;
 853                         case TOMOYO_NUMBER_UNION:
 854                                 /* Fetch values later. */
 855                                 break;
 856                         default:
 857                                 if (!obj)
 858                                         goto out;
 859                                 if (!obj->validate_done) {
 860                                         tomoyo_get_attributes(obj);
 861                                         obj->validate_done = true;
 862                                 }
 863                                 {
 864                                         u8 stat_index;
 865                                         struct tomoyo_mini_stat *stat;
 866                                         switch (index) {
 867                                         case TOMOYO_PATH1_UID:
 868                                         case TOMOYO_PATH1_GID:
 869                                         case TOMOYO_PATH1_INO:
 870                                         case TOMOYO_PATH1_MAJOR:
 871                                         case TOMOYO_PATH1_MINOR:
 872                                         case TOMOYO_PATH1_TYPE:
 873                                         case TOMOYO_PATH1_DEV_MAJOR:
 874                                         case TOMOYO_PATH1_DEV_MINOR:
 875                                         case TOMOYO_PATH1_PERM:
 876                                                 stat_index = TOMOYO_PATH1;
 877                                                 break;
 878                                         case TOMOYO_PATH2_UID:
 879                                         case TOMOYO_PATH2_GID:
 880                                         case TOMOYO_PATH2_INO:
 881                                         case TOMOYO_PATH2_MAJOR:
 882                                         case TOMOYO_PATH2_MINOR:
 883                                         case TOMOYO_PATH2_TYPE:
 884                                         case TOMOYO_PATH2_DEV_MAJOR:
 885                                         case TOMOYO_PATH2_DEV_MINOR:
 886                                         case TOMOYO_PATH2_PERM:
 887                                                 stat_index = TOMOYO_PATH2;
 888                                                 break;
 889                                         case TOMOYO_PATH1_PARENT_UID:
 890                                         case TOMOYO_PATH1_PARENT_GID:
 891                                         case TOMOYO_PATH1_PARENT_INO:
 892                                         case TOMOYO_PATH1_PARENT_PERM:
 893                                                 stat_index =
 894                                                         TOMOYO_PATH1_PARENT;
 895                                                 break;
 896                                         case TOMOYO_PATH2_PARENT_UID:
 897                                         case TOMOYO_PATH2_PARENT_GID:
 898                                         case TOMOYO_PATH2_PARENT_INO:
 899                                         case TOMOYO_PATH2_PARENT_PERM:
 900                                                 stat_index =
 901                                                         TOMOYO_PATH2_PARENT;
 902                                                 break;
 903                                         default:
 904                                                 goto out;
 905                                         }
 906                                         if (!obj->stat_valid[stat_index])
 907                                                 goto out;
 908                                         stat = &obj->stat[stat_index];
 909                                         switch (index) {
 910                                         case TOMOYO_PATH1_UID:
 911                                         case TOMOYO_PATH2_UID:
 912                                         case TOMOYO_PATH1_PARENT_UID:
 913                                         case TOMOYO_PATH2_PARENT_UID:
 914                                                 value = stat->uid;
 915                                                 break;
 916                                         case TOMOYO_PATH1_GID:
 917                                         case TOMOYO_PATH2_GID:
 918                                         case TOMOYO_PATH1_PARENT_GID:
 919                                         case TOMOYO_PATH2_PARENT_GID:
 920                                                 value = stat->gid;
 921                                                 break;
 922                                         case TOMOYO_PATH1_INO:
 923                                         case TOMOYO_PATH2_INO:
 924                                         case TOMOYO_PATH1_PARENT_INO:
 925                                         case TOMOYO_PATH2_PARENT_INO:
 926                                                 value = stat->ino;
 927                                                 break;
 928                                         case TOMOYO_PATH1_MAJOR:
 929                                         case TOMOYO_PATH2_MAJOR:
 930                                                 value = MAJOR(stat->dev);
 931                                                 break;
 932                                         case TOMOYO_PATH1_MINOR:
 933                                         case TOMOYO_PATH2_MINOR:
 934                                                 value = MINOR(stat->dev);
 935                                                 break;
 936                                         case TOMOYO_PATH1_TYPE:
 937                                         case TOMOYO_PATH2_TYPE:
 938                                                 value = stat->mode & S_IFMT;
 939                                                 break;
 940                                         case TOMOYO_PATH1_DEV_MAJOR:
 941                                         case TOMOYO_PATH2_DEV_MAJOR:
 942                                                 value = MAJOR(stat->rdev);
 943                                                 break;
 944                                         case TOMOYO_PATH1_DEV_MINOR:
 945                                         case TOMOYO_PATH2_DEV_MINOR:
 946                                                 value = MINOR(stat->rdev);
 947                                                 break;
 948                                         case TOMOYO_PATH1_PERM:
 949                                         case TOMOYO_PATH2_PERM:
 950                                         case TOMOYO_PATH1_PARENT_PERM:
 951                                         case TOMOYO_PATH2_PARENT_PERM:
 952                                                 value = stat->mode & S_IALLUGO;
 953                                                 break;
 954                                         }
 955                                 }
 956                                 break;
 957                         }
 958                         max_v[j] = value;
 959                         min_v[j] = value;
 960                         switch (index) {
 961                         case TOMOYO_MODE_SETUID:
 962                         case TOMOYO_MODE_SETGID:
 963                         case TOMOYO_MODE_STICKY:
 964                         case TOMOYO_MODE_OWNER_READ:
 965                         case TOMOYO_MODE_OWNER_WRITE:
 966                         case TOMOYO_MODE_OWNER_EXECUTE:
 967                         case TOMOYO_MODE_GROUP_READ:
 968                         case TOMOYO_MODE_GROUP_WRITE:
 969                         case TOMOYO_MODE_GROUP_EXECUTE:
 970                         case TOMOYO_MODE_OTHERS_READ:
 971                         case TOMOYO_MODE_OTHERS_WRITE:
 972                         case TOMOYO_MODE_OTHERS_EXECUTE:
 973                                 is_bitop[j] = true;
 974                         }
 975                 }
 976                 if (left == TOMOYO_NUMBER_UNION) {
 977                         /* Fetch values now. */
 978                         const struct tomoyo_number_union *ptr = numbers_p++;
 979                         min_v[0] = ptr->values[0];
 980                         max_v[0] = ptr->values[1];
 981                 }
 982                 if (right == TOMOYO_NUMBER_UNION) {
 983                         /* Fetch values now. */
 984                         const struct tomoyo_number_union *ptr = numbers_p++;
 985                         if (ptr->group) {
 986                                 if (tomoyo_number_matches_group(min_v[0],
 987                                                                 max_v[0],
 988                                                                 ptr->group)
 989                                     == match)
 990                                         continue;
 991                         } else {
 992                                 if ((min_v[0] <= ptr->values[1] &&
 993                                      max_v[0] >= ptr->values[0]) == match)
 994                                         continue;
 995                         }
 996                         goto out;
 997                 }
 998                 /*
 999                  * Bit operation is valid only when counterpart value
1000                  * represents permission.
1001                  */
1002                 if (is_bitop[0] && is_bitop[1]) {
1003                         goto out;
1004                 } else if (is_bitop[0]) {
1005                         switch (right) {
1006                         case TOMOYO_PATH1_PERM:
1007                         case TOMOYO_PATH1_PARENT_PERM:
1008                         case TOMOYO_PATH2_PERM:
1009                         case TOMOYO_PATH2_PARENT_PERM:
1010                                 if (!(max_v[0] & max_v[1]) == !match)
1011                                         continue;
1012                         }
1013                         goto out;
1014                 } else if (is_bitop[1]) {
1015                         switch (left) {
1016                         case TOMOYO_PATH1_PERM:
1017                         case TOMOYO_PATH1_PARENT_PERM:
1018                         case TOMOYO_PATH2_PERM:
1019                         case TOMOYO_PATH2_PARENT_PERM:
1020                                 if (!(max_v[0] & max_v[1]) == !match)
1021                                         continue;
1022                         }
1023                         goto out;
1024                 }
1025                 /* Normal value range comparison. */
1026                 if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
1027                         continue;
1028 out:
1029                 return false;
1030         }
1031         /* Check argv[] and envp[] now. */
1032         if (r->ee && (argc || envc))
1033                 return tomoyo_scan_bprm(r->ee, argc, argv, envc, envp);
1034         return true;
1035 }