linux/security/tomoyo/condition.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * security/tomoyo/condition.c
   4 *
   5 * Copyright (C) 2005-2011  NTT DATA CORPORATION
   6 */
   7
   8#include "common.h"
   9#include <linux/slab.h>
  10
  11/* List of "struct tomoyo_condition". */
  12LIST_HEAD(tomoyo_condition_list);
  13
  14/**
  15 * tomoyo_argv - Check argv[] in "struct linux_binbrm".
  16 *
  17 * @index:   Index number of @arg_ptr.
  18 * @arg_ptr: Contents of argv[@index].
  19 * @argc:    Length of @argv.
  20 * @argv:    Pointer to "struct tomoyo_argv".
  21 * @checked: Set to true if @argv[@index] was found.
  22 *
  23 * Returns true on success, false otherwise.
  24 */
  25static bool tomoyo_argv(const unsigned int index, const char *arg_ptr,
  26                        const int argc, const struct tomoyo_argv *argv,
  27                        u8 *checked)
  28{
  29        int i;
  30        struct tomoyo_path_info arg;
  31        arg.name = arg_ptr;
  32        for (i = 0; i < argc; argv++, checked++, i++) {
  33                bool result;
  34                if (index != argv->index)
  35                        continue;
  36                *checked = 1;
  37                tomoyo_fill_path_info(&arg);
  38                result = tomoyo_path_matches_pattern(&arg, argv->value);
  39                if (argv->is_not)
  40                        result = !result;
  41                if (!result)
  42                        return false;
  43        }
  44        return true;
  45}
  46
  47/**
  48 * tomoyo_envp - Check envp[] in "struct linux_binbrm".
  49 *
  50 * @env_name:  The name of environment variable.
  51 * @env_value: The value of environment variable.
  52 * @envc:      Length of @envp.
  53 * @envp:      Pointer to "struct tomoyo_envp".
  54 * @checked:   Set to true if @envp[@env_name] was found.
  55 *
  56 * Returns true on success, false otherwise.
  57 */
  58static bool tomoyo_envp(const char *env_name, const char *env_value,
  59                        const int envc, const struct tomoyo_envp *envp,
  60                        u8 *checked)
  61{
  62        int i;
  63        struct tomoyo_path_info name;
  64        struct tomoyo_path_info value;
  65        name.name = env_name;
  66        tomoyo_fill_path_info(&name);
  67        value.name = env_value;
  68        tomoyo_fill_path_info(&value);
  69        for (i = 0; i < envc; envp++, checked++, i++) {
  70                bool result;
  71                if (!tomoyo_path_matches_pattern(&name, envp->name))
  72                        continue;
  73                *checked = 1;
  74                if (envp->value) {
  75                        result = tomoyo_path_matches_pattern(&value,
  76                                                             envp->value);
  77                        if (envp->is_not)
  78                                result = !result;
  79                } else {
  80                        result = true;
  81                        if (!envp->is_not)
  82                                result = !result;
  83                }
  84                if (!result)
  85                        return false;
  86        }
  87        return true;
  88}
  89
  90/**
  91 * tomoyo_scan_bprm - Scan "struct linux_binprm".
  92 *
  93 * @ee:   Pointer to "struct tomoyo_execve".
  94 * @argc: Length of @argc.
  95 * @argv: Pointer to "struct tomoyo_argv".
  96 * @envc: Length of @envp.
  97 * @envp: Poiner to "struct tomoyo_envp".
  98 *
  99 * Returns true on success, false otherwise.
 100 */
 101static bool tomoyo_scan_bprm(struct tomoyo_execve *ee,
 102                             const u16 argc, const struct tomoyo_argv *argv,
 103                             const u16 envc, const struct tomoyo_envp *envp)
 104{
 105        struct linux_binprm *bprm = ee->bprm;
 106        struct tomoyo_page_dump *dump = &ee->dump;
 107        char *arg_ptr = ee->tmp;
 108        int arg_len = 0;
 109        unsigned long pos = bprm->p;
 110        int offset = pos % PAGE_SIZE;
 111        int argv_count = bprm->argc;
 112        int envp_count = bprm->envc;
 113        bool result = true;
 114        u8 local_checked[32];
 115        u8 *checked;
 116        if (argc + envc <= sizeof(local_checked)) {
 117                checked = local_checked;
 118                memset(local_checked, 0, sizeof(local_checked));
 119        } else {
 120                checked = kzalloc(argc + envc, GFP_NOFS);
 121                if (!checked)
 122                        return false;
 123        }
 124        while (argv_count || envp_count) {
 125                if (!tomoyo_dump_page(bprm, pos, dump)) {
 126                        result = false;
 127                        goto out;
 128                }
 129                pos += PAGE_SIZE - offset;
 130                while (offset < PAGE_SIZE) {
 131                        /* Read. */
 132                        const char *kaddr = dump->data;
 133                        const unsigned char c = kaddr[offset++];
 134                        if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
 135                                if (c == '\\') {
 136                                        arg_ptr[arg_len++] = '\\';
 137                                        arg_ptr[arg_len++] = '\\';
 138                                } else if (c > ' ' && c < 127) {
 139                                        arg_ptr[arg_len++] = c;
 140                                } else {
 141                                        arg_ptr[arg_len++] = '\\';
 142                                        arg_ptr[arg_len++] = (c >> 6) + '0';
 143                                        arg_ptr[arg_len++] =
 144                                                ((c >> 3) & 7) + '0';
 145                                        arg_ptr[arg_len++] = (c & 7) + '0';
 146                                }
 147                        } else {
 148                                arg_ptr[arg_len] = '\0';
 149                        }
 150                        if (c)
 151                                continue;
 152                        /* Check. */
 153                        if (argv_count) {
 154                                if (!tomoyo_argv(bprm->argc - argv_count,
 155                                                 arg_ptr, argc, argv,
 156                                                 checked)) {
 157                                        result = false;
 158                                        break;
 159                                }
 160                                argv_count--;
 161                        } else if (envp_count) {
 162                                char *cp = strchr(arg_ptr, '=');
 163                                if (cp) {
 164                                        *cp = '\0';
 165                                        if (!tomoyo_envp(arg_ptr, cp + 1,
 166                                                         envc, envp,
 167                                                         checked + argc)) {
 168                                                result = false;
 169                                                break;
 170                                        }
 171                                }
 172                                envp_count--;
 173                        } else {
 174                                break;
 175                        }
 176                        arg_len = 0;
 177                }
 178                offset = 0;
 179                if (!result)
 180                        break;
 181        }
 182out:
 183        if (result) {
 184                int i;
 185                /* Check not-yet-checked entries. */
 186                for (i = 0; i < argc; i++) {
 187                        if (checked[i])
 188                                continue;
 189                        /*
 190                         * Return true only if all unchecked indexes in
 191                         * bprm->argv[] are not matched.
 192                         */
 193                        if (argv[i].is_not)
 194                                continue;
 195                        result = false;
 196                        break;
 197                }
 198                for (i = 0; i < envc; envp++, i++) {
 199                        if (checked[argc + i])
 200                                continue;
 201                        /*
 202                         * Return true only if all unchecked environ variables
 203                         * in bprm->envp[] are either undefined or not matched.
 204                         */
 205                        if ((!envp->value && !envp->is_not) ||
 206                            (envp->value && envp->is_not))
 207                                continue;
 208                        result = false;
 209                        break;
 210                }
 211        }
 212        if (checked != local_checked)
 213                kfree(checked);
 214        return result;
 215}
 216
 217/**
 218 * tomoyo_scan_exec_realpath - Check "exec.realpath" parameter of "struct tomoyo_condition".
 219 *
 220 * @file:  Pointer to "struct file".
 221 * @ptr:   Pointer to "struct tomoyo_name_union".
 222 * @match: True if "exec.realpath=", false if "exec.realpath!=".
 223 *
 224 * Returns true on success, false otherwise.
 225 */
 226static bool tomoyo_scan_exec_realpath(struct file *file,
 227                                      const struct tomoyo_name_union *ptr,
 228                                      const bool match)
 229{
 230        bool result;
 231        struct tomoyo_path_info exe;
 232        if (!file)
 233                return false;
 234        exe.name = tomoyo_realpath_from_path(&file->f_path);
 235        if (!exe.name)
 236                return false;
 237        tomoyo_fill_path_info(&exe);
 238        result = tomoyo_compare_name_union(&exe, ptr);
 239        kfree(exe.name);
 240        return result == match;
 241}
 242
 243/**
 244 * tomoyo_get_dqword - tomoyo_get_name() for a quoted string.
 245 *
 246 * @start: String to save.
 247 *
 248 * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
 249 */
 250static const struct tomoyo_path_info *tomoyo_get_dqword(char *start)
 251{
 252        char *cp = start + strlen(start) - 1;
 253        if (cp == start || *start++ != '"' || *cp != '"')
 254                return NULL;
 255        *cp = '\0';
 256        if (*start && !tomoyo_correct_word(start))
 257                return NULL;
 258        return tomoyo_get_name(start);
 259}
 260
 261/**
 262 * tomoyo_parse_name_union_quoted - Parse a quoted word.
 263 *
 264 * @param: Pointer to "struct tomoyo_acl_param".
 265 * @ptr:   Pointer to "struct tomoyo_name_union".
 266 *
 267 * Returns true on success, false otherwise.
 268 */
 269static bool tomoyo_parse_name_union_quoted(struct tomoyo_acl_param *param,
 270                                           struct tomoyo_name_union *ptr)
 271{
 272        char *filename = param->data;
 273        if (*filename == '@')
 274                return tomoyo_parse_name_union(param, ptr);
 275        ptr->filename = tomoyo_get_dqword(filename);
 276        return ptr->filename != NULL;
 277}
 278
 279/**
 280 * tomoyo_parse_argv - Parse an argv[] condition part.
 281 *
 282 * @left:  Lefthand value.
 283 * @right: Righthand value.
 284 * @argv:  Pointer to "struct tomoyo_argv".
 285 *
 286 * Returns true on success, false otherwise.
 287 */
 288static bool tomoyo_parse_argv(char *left, char *right,
 289                              struct tomoyo_argv *argv)
 290{
 291        if (tomoyo_parse_ulong(&argv->index, &left) !=
 292            TOMOYO_VALUE_TYPE_DECIMAL || *left++ != ']' || *left)
 293                return false;
 294        argv->value = tomoyo_get_dqword(right);
 295        return argv->value != NULL;
 296}
 297
 298/**
 299 * tomoyo_parse_envp - Parse an envp[] condition part.
 300 *
 301 * @left:  Lefthand value.
 302 * @right: Righthand value.
 303 * @envp:  Pointer to "struct tomoyo_envp".
 304 *
 305 * Returns true on success, false otherwise.
 306 */
 307static bool tomoyo_parse_envp(char *left, char *right,
 308                              struct tomoyo_envp *envp)
 309{
 310        const struct tomoyo_path_info *name;
 311        const struct tomoyo_path_info *value;
 312        char *cp = left + strlen(left) - 1;
 313        if (*cp-- != ']' || *cp != '"')
 314                goto out;
 315        *cp = '\0';
 316        if (!tomoyo_correct_word(left))
 317                goto out;
 318        name = tomoyo_get_name(left);
 319        if (!name)
 320                goto out;
 321        if (!strcmp(right, "NULL")) {
 322                value = NULL;
 323        } else {
 324                value = tomoyo_get_dqword(right);
 325                if (!value) {
 326                        tomoyo_put_name(name);
 327                        goto out;
 328                }
 329        }
 330        envp->name = name;
 331        envp->value = value;
 332        return true;
 333out:
 334        return false;
 335}
 336
 337/**
 338 * tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry.
 339 *
 340 * @a: Pointer to "struct tomoyo_condition".
 341 * @b: Pointer to "struct tomoyo_condition".
 342 *
 343 * Returns true if @a == @b, false otherwise.
 344 */
 345static inline bool tomoyo_same_condition(const struct tomoyo_condition *a,
 346                                         const struct tomoyo_condition *b)
 347{
 348        return a->size == b->size && a->condc == b->condc &&
 349                a->numbers_count == b->numbers_count &&
 350                a->names_count == b->names_count &&
 351                a->argc == b->argc && a->envc == b->envc &&
 352                a->grant_log == b->grant_log && a->transit == b->transit &&
 353                !memcmp(a + 1, b + 1, a->size - sizeof(*a));
 354}
 355
 356/**
 357 * tomoyo_condition_type - Get condition type.
 358 *
 359 * @word: Keyword string.
 360 *
 361 * Returns one of values in "enum tomoyo_conditions_index" on success,
 362 * TOMOYO_MAX_CONDITION_KEYWORD otherwise.
 363 */
 364static u8 tomoyo_condition_type(const char *word)
 365{
 366        u8 i;
 367        for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) {
 368                if (!strcmp(word, tomoyo_condition_keyword[i]))
 369                        break;
 370        }
 371        return i;
 372}
 373
 374/* Define this to enable debug mode. */
 375/* #define DEBUG_CONDITION */
 376
 377#ifdef DEBUG_CONDITION
 378#define dprintk printk
 379#else
 380#define dprintk(...) do { } while (0)
 381#endif
 382
 383/**
 384 * tomoyo_commit_condition - Commit "struct tomoyo_condition".
 385 *
 386 * @entry: Pointer to "struct tomoyo_condition".
 387 *
 388 * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
 389 *
 390 * This function merges duplicated entries. This function returns NULL if
 391 * @entry is not duplicated but memory quota for policy has exceeded.
 392 */
 393static struct tomoyo_condition *tomoyo_commit_condition
 394(struct tomoyo_condition *entry)
 395{
 396        struct tomoyo_condition *ptr;
 397        bool found = false;
 398        if (mutex_lock_interruptible(&tomoyo_policy_lock)) {
 399                dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
 400                ptr = NULL;
 401                found = true;
 402                goto out;
 403        }
 404        list_for_each_entry(ptr, &tomoyo_condition_list, head.list) {
 405                if (!tomoyo_same_condition(ptr, entry) ||
 406                    atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS)
 407                        continue;
 408                /* Same entry found. Share this entry. */
 409                atomic_inc(&ptr->head.users);
 410                found = true;
 411                break;
 412        }
 413        if (!found) {
 414                if (tomoyo_memory_ok(entry)) {
 415                        atomic_set(&entry->head.users, 1);
 416                        list_add(&entry->head.list, &tomoyo_condition_list);
 417                } else {
 418                        found = true;
 419                        ptr = NULL;
 420                }
 421        }
 422        mutex_unlock(&tomoyo_policy_lock);
 423out:
 424        if (found) {
 425                tomoyo_del_condition(&entry->head.list);
 426                kfree(entry);
 427                entry = ptr;
 428        }
 429        return entry;
 430}
 431
 432/**
 433 * tomoyo_get_transit_preference - Parse domain transition preference for execve().
 434 *
 435 * @param: Pointer to "struct tomoyo_acl_param".
 436 * @e:     Pointer to "struct tomoyo_condition".
 437 *
 438 * Returns the condition string part.
 439 */
 440static char *tomoyo_get_transit_preference(struct tomoyo_acl_param *param,
 441                                           struct tomoyo_condition *e)
 442{
 443        char * const pos = param->data;
 444        bool flag;
 445        if (*pos == '<') {
 446                e->transit = tomoyo_get_domainname(param);
 447                goto done;
 448        }
 449        {
 450                char *cp = strchr(pos, ' ');
 451                if (cp)
 452                        *cp = '\0';
 453                flag = tomoyo_correct_path(pos) || !strcmp(pos, "keep") ||
 454                        !strcmp(pos, "initialize") || !strcmp(pos, "reset") ||
 455                        !strcmp(pos, "child") || !strcmp(pos, "parent");
 456                if (cp)
 457                        *cp = ' ';
 458        }
 459        if (!flag)
 460                return pos;
 461        e->transit = tomoyo_get_name(tomoyo_read_token(param));
 462done:
 463        if (e->transit)
 464                return param->data;
 465        /*
 466         * Return a bad read-only condition string that will let
 467         * tomoyo_get_condition() return NULL.
 468         */
 469        return "/";
 470}
 471
 472/**
 473 * tomoyo_get_condition - Parse condition part.
 474 *
 475 * @param: Pointer to "struct tomoyo_acl_param".
 476 *
 477 * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
 478 */
 479struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param)
 480{
 481        struct tomoyo_condition *entry = NULL;
 482        struct tomoyo_condition_element *condp = NULL;
 483        struct tomoyo_number_union *numbers_p = NULL;
 484        struct tomoyo_name_union *names_p = NULL;
 485        struct tomoyo_argv *argv = NULL;
 486        struct tomoyo_envp *envp = NULL;
 487        struct tomoyo_condition e = { };
 488        char * const start_of_string =
 489                tomoyo_get_transit_preference(param, &e);
 490        char * const end_of_string = start_of_string + strlen(start_of_string);
 491        char *pos;
 492rerun:
 493        pos = start_of_string;
 494        while (1) {
 495                u8 left = -1;
 496                u8 right = -1;
 497                char *left_word = pos;
 498                char *cp;
 499                char *right_word;
 500                bool is_not;
 501                if (!*left_word)
 502                        break;
 503                /*
 504                 * Since left-hand condition does not allow use of "path_group"
 505                 * or "number_group" and environment variable's names do not
 506                 * accept '=', it is guaranteed that the original line consists
 507                 * of one or more repetition of $left$operator$right blocks
 508                 * where "$left is free from '=' and ' '" and "$operator is
 509                 * either '=' or '!='" and "$right is free from ' '".
 510                 * Therefore, we can reconstruct the original line at the end
 511                 * of dry run even if we overwrite $operator with '\0'.
 512                 */
 513                cp = strchr(pos, ' ');
 514                if (cp) {
 515                        *cp = '\0'; /* Will restore later. */
 516                        pos = cp + 1;
 517                } else {
 518                        pos = "";
 519                }
 520                right_word = strchr(left_word, '=');
 521                if (!right_word || right_word == left_word)
 522                        goto out;
 523                is_not = *(right_word - 1) == '!';
 524                if (is_not)
 525                        *(right_word++ - 1) = '\0'; /* Will restore later. */
 526                else if (*(right_word + 1) != '=')
 527                        *right_word++ = '\0'; /* Will restore later. */
 528                else
 529                        goto out;
 530                dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word,
 531                        is_not ? "!" : "", right_word);
 532                if (!strcmp(left_word, "grant_log")) {
 533                        if (entry) {
 534                                if (is_not ||
 535                                    entry->grant_log != TOMOYO_GRANTLOG_AUTO)
 536                                        goto out;
 537                                else if (!strcmp(right_word, "yes"))
 538                                        entry->grant_log = TOMOYO_GRANTLOG_YES;
 539                                else if (!strcmp(right_word, "no"))
 540                                        entry->grant_log = TOMOYO_GRANTLOG_NO;
 541                                else
 542                                        goto out;
 543                        }
 544                        continue;
 545                }
 546                if (!strncmp(left_word, "exec.argv[", 10)) {
 547                        if (!argv) {
 548                                e.argc++;
 549                                e.condc++;
 550                        } else {
 551                                e.argc--;
 552                                e.condc--;
 553                                left = TOMOYO_ARGV_ENTRY;
 554                                argv->is_not = is_not;
 555                                if (!tomoyo_parse_argv(left_word + 10,
 556                                                       right_word, argv++))
 557                                        goto out;
 558                        }
 559                        goto store_value;
 560                }
 561                if (!strncmp(left_word, "exec.envp[\"", 11)) {
 562                        if (!envp) {
 563                                e.envc++;
 564                                e.condc++;
 565                        } else {
 566                                e.envc--;
 567                                e.condc--;
 568                                left = TOMOYO_ENVP_ENTRY;
 569                                envp->is_not = is_not;
 570                                if (!tomoyo_parse_envp(left_word + 11,
 571                                                       right_word, envp++))
 572                                        goto out;
 573                        }
 574                        goto store_value;
 575                }
 576                left = tomoyo_condition_type(left_word);
 577                dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word,
 578                        left);
 579                if (left == TOMOYO_MAX_CONDITION_KEYWORD) {
 580                        if (!numbers_p) {
 581                                e.numbers_count++;
 582                        } else {
 583                                e.numbers_count--;
 584                                left = TOMOYO_NUMBER_UNION;
 585                                param->data = left_word;
 586                                if (*left_word == '@' ||
 587                                    !tomoyo_parse_number_union(param,
 588                                                               numbers_p++))
 589                                        goto out;
 590                        }
 591                }
 592                if (!condp)
 593                        e.condc++;
 594                else
 595                        e.condc--;
 596                if (left == TOMOYO_EXEC_REALPATH ||
 597                    left == TOMOYO_SYMLINK_TARGET) {
 598                        if (!names_p) {
 599                                e.names_count++;
 600                        } else {
 601                                e.names_count--;
 602                                right = TOMOYO_NAME_UNION;
 603                                param->data = right_word;
 604                                if (!tomoyo_parse_name_union_quoted(param,
 605                                                                    names_p++))
 606                                        goto out;
 607                        }
 608                        goto store_value;
 609                }
 610                right = tomoyo_condition_type(right_word);
 611                if (right == TOMOYO_MAX_CONDITION_KEYWORD) {
 612                        if (!numbers_p) {
 613                                e.numbers_count++;
 614                        } else {
 615                                e.numbers_count--;
 616                                right = TOMOYO_NUMBER_UNION;
 617                                param->data = right_word;
 618                                if (!tomoyo_parse_number_union(param,
 619                                                               numbers_p++))
 620                                        goto out;
 621                        }
 622                }
 623store_value:
 624                if (!condp) {
 625                        dprintk(KERN_WARNING "%u: dry_run left=%u right=%u "
 626                                "match=%u\n", __LINE__, left, right, !is_not);
 627                        continue;
 628                }
 629                condp->left = left;
 630                condp->right = right;
 631                condp->equals = !is_not;
 632                dprintk(KERN_WARNING "%u: left=%u right=%u match=%u\n",
 633                        __LINE__, condp->left, condp->right,
 634                        condp->equals);
 635                condp++;
 636        }
 637        dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u ac=%u ec=%u\n",
 638                __LINE__, e.condc, e.numbers_count, e.names_count, e.argc,
 639                e.envc);
 640        if (entry) {
 641                BUG_ON(e.names_count | e.numbers_count | e.argc | e.envc |
 642                       e.condc);
 643                return tomoyo_commit_condition(entry);
 644        }
 645        e.size = sizeof(*entry)
 646                + e.condc * sizeof(struct tomoyo_condition_element)
 647                + e.numbers_count * sizeof(struct tomoyo_number_union)
 648                + e.names_count * sizeof(struct tomoyo_name_union)
 649                + e.argc * sizeof(struct tomoyo_argv)
 650                + e.envc * sizeof(struct tomoyo_envp);
 651        entry = kzalloc(e.size, GFP_NOFS);
 652        if (!entry)
 653                goto out2;
 654        *entry = e;
 655        e.transit = NULL;
 656        condp = (struct tomoyo_condition_element *) (entry + 1);
 657        numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
 658        names_p = (struct tomoyo_name_union *) (numbers_p + e.numbers_count);
 659        argv = (struct tomoyo_argv *) (names_p + e.names_count);
 660        envp = (struct tomoyo_envp *) (argv + e.argc);
 661        {
 662                bool flag = false;
 663                for (pos = start_of_string; pos < end_of_string; pos++) {
 664                        if (*pos)
 665                                continue;
 666                        if (flag) /* Restore " ". */
 667                                *pos = ' ';
 668                        else if (*(pos + 1) == '=') /* Restore "!=". */
 669                                *pos = '!';
 670                        else /* Restore "=". */
 671                                *pos = '=';
 672                        flag = !flag;
 673                }
 674        }
 675        goto rerun;
 676out:
 677        dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
 678        if (entry) {
 679                tomoyo_del_condition(&entry->head.list);
 680                kfree(entry);
 681        }
 682out2:
 683        tomoyo_put_name(e.transit);
 684        return NULL;
 685}
 686
 687/**
 688 * tomoyo_get_attributes - Revalidate "struct inode".
 689 *
 690 * @obj: Pointer to "struct tomoyo_obj_info".
 691 *
 692 * Returns nothing.
 693 */
 694void tomoyo_get_attributes(struct tomoyo_obj_info *obj)
 695{
 696        u8 i;
 697        struct dentry *dentry = NULL;
 698
 699        for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
 700                struct inode *inode;
 701                switch (i) {
 702                case TOMOYO_PATH1:
 703                        dentry = obj->path1.dentry;
 704                        if (!dentry)
 705                                continue;
 706                        break;
 707                case TOMOYO_PATH2:
 708                        dentry = obj->path2.dentry;
 709                        if (!dentry)
 710                                continue;
 711                        break;
 712                default:
 713                        if (!dentry)
 714                                continue;
 715                        dentry = dget_parent(dentry);
 716                        break;
 717                }
 718                inode = d_backing_inode(dentry);
 719                if (inode) {
 720                        struct tomoyo_mini_stat *stat = &obj->stat[i];
 721                        stat->uid  = inode->i_uid;
 722                        stat->gid  = inode->i_gid;
 723                        stat->ino  = inode->i_ino;
 724                        stat->mode = inode->i_mode;
 725                        stat->dev  = inode->i_sb->s_dev;
 726                        stat->rdev = inode->i_rdev;
 727                        obj->stat_valid[i] = true;
 728                }
 729                if (i & 1) /* i == TOMOYO_PATH1_PARENT ||
 730                              i == TOMOYO_PATH2_PARENT */
 731                        dput(dentry);
 732        }
 733}
 734
 735/**
 736 * tomoyo_condition - Check condition part.
 737 *
 738 * @r:    Pointer to "struct tomoyo_request_info".
 739 * @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
 740 *
 741 * Returns true on success, false otherwise.
 742 *
 743 * Caller holds tomoyo_read_lock().
 744 */
 745bool tomoyo_condition(struct tomoyo_request_info *r,
 746                      const struct tomoyo_condition *cond)
 747{
 748        u32 i;
 749        unsigned long min_v[2] = { 0, 0 };
 750        unsigned long max_v[2] = { 0, 0 };
 751        const struct tomoyo_condition_element *condp;
 752        const struct tomoyo_number_union *numbers_p;
 753        const struct tomoyo_name_union *names_p;
 754        const struct tomoyo_argv *argv;
 755        const struct tomoyo_envp *envp;
 756        struct tomoyo_obj_info *obj;
 757        u16 condc;
 758        u16 argc;
 759        u16 envc;
 760        struct linux_binprm *bprm = NULL;
 761        if (!cond)
 762                return true;
 763        condc = cond->condc;
 764        argc = cond->argc;
 765        envc = cond->envc;
 766        obj = r->obj;
 767        if (r->ee)
 768                bprm = r->ee->bprm;
 769        if (!bprm && (argc || envc))
 770                return false;
 771        condp = (struct tomoyo_condition_element *) (cond + 1);
 772        numbers_p = (const struct tomoyo_number_union *) (condp + condc);
 773        names_p = (const struct tomoyo_name_union *)
 774                (numbers_p + cond->numbers_count);
 775        argv = (const struct tomoyo_argv *) (names_p + cond->names_count);
 776        envp = (const struct tomoyo_envp *) (argv + argc);
 777        for (i = 0; i < condc; i++) {
 778                const bool match = condp->equals;
 779                const u8 left = condp->left;
 780                const u8 right = condp->right;
 781                bool is_bitop[2] = { false, false };
 782                u8 j;
 783                condp++;
 784                /* Check argv[] and envp[] later. */
 785                if (left == TOMOYO_ARGV_ENTRY || left == TOMOYO_ENVP_ENTRY)
 786                        continue;
 787                /* Check string expressions. */
 788                if (right == TOMOYO_NAME_UNION) {
 789                        const struct tomoyo_name_union *ptr = names_p++;
 790                        switch (left) {
 791                                struct tomoyo_path_info *symlink;
 792                                struct tomoyo_execve *ee;
 793                                struct file *file;
 794                        case TOMOYO_SYMLINK_TARGET:
 795                                symlink = obj ? obj->symlink_target : NULL;
 796                                if (!symlink ||
 797                                    !tomoyo_compare_name_union(symlink, ptr)
 798                                    == match)
 799                                        goto out;
 800                                break;
 801                        case TOMOYO_EXEC_REALPATH:
 802                                ee = r->ee;
 803                                file = ee ? ee->bprm->file : NULL;
 804                                if (!tomoyo_scan_exec_realpath(file, ptr,
 805                                                               match))
 806                                        goto out;
 807                                break;
 808                        }
 809                        continue;
 810                }
 811                /* Check numeric or bit-op expressions. */
 812                for (j = 0; j < 2; j++) {
 813                        const u8 index = j ? right : left;
 814                        unsigned long value = 0;
 815                        switch (index) {
 816                        case TOMOYO_TASK_UID:
 817                                value = from_kuid(&init_user_ns, current_uid());
 818                                break;
 819                        case TOMOYO_TASK_EUID:
 820                                value = from_kuid(&init_user_ns, current_euid());
 821                                break;
 822                        case TOMOYO_TASK_SUID:
 823                                value = from_kuid(&init_user_ns, current_suid());
 824                                break;
 825                        case TOMOYO_TASK_FSUID:
 826                                value = from_kuid(&init_user_ns, current_fsuid());
 827                                break;
 828                        case TOMOYO_TASK_GID:
 829                                value = from_kgid(&init_user_ns, current_gid());
 830                                break;
 831                        case TOMOYO_TASK_EGID:
 832                                value = from_kgid(&init_user_ns, current_egid());
 833                                break;
 834                        case TOMOYO_TASK_SGID:
 835                                value = from_kgid(&init_user_ns, current_sgid());
 836                                break;
 837                        case TOMOYO_TASK_FSGID:
 838                                value = from_kgid(&init_user_ns, current_fsgid());
 839                                break;
 840                        case TOMOYO_TASK_PID:
 841                                value = tomoyo_sys_getpid();
 842                                break;
 843                        case TOMOYO_TASK_PPID:
 844                                value = tomoyo_sys_getppid();
 845                                break;
 846                        case TOMOYO_TYPE_IS_SOCKET:
 847                                value = S_IFSOCK;
 848                                break;
 849                        case TOMOYO_TYPE_IS_SYMLINK:
 850                                value = S_IFLNK;
 851                                break;
 852                        case TOMOYO_TYPE_IS_FILE:
 853                                value = S_IFREG;
 854                                break;
 855                        case TOMOYO_TYPE_IS_BLOCK_DEV:
 856                                value = S_IFBLK;
 857                                break;
 858                        case TOMOYO_TYPE_IS_DIRECTORY:
 859                                value = S_IFDIR;
 860                                break;
 861                        case TOMOYO_TYPE_IS_CHAR_DEV:
 862                                value = S_IFCHR;
 863                                break;
 864                        case TOMOYO_TYPE_IS_FIFO:
 865                                value = S_IFIFO;
 866                                break;
 867                        case TOMOYO_MODE_SETUID:
 868                                value = S_ISUID;
 869                                break;
 870                        case TOMOYO_MODE_SETGID:
 871                                value = S_ISGID;
 872                                break;
 873                        case TOMOYO_MODE_STICKY:
 874                                value = S_ISVTX;
 875                                break;
 876                        case TOMOYO_MODE_OWNER_READ:
 877                                value = S_IRUSR;
 878                                break;
 879                        case TOMOYO_MODE_OWNER_WRITE:
 880                                value = S_IWUSR;
 881                                break;
 882                        case TOMOYO_MODE_OWNER_EXECUTE:
 883                                value = S_IXUSR;
 884                                break;
 885                        case TOMOYO_MODE_GROUP_READ:
 886                                value = S_IRGRP;
 887                                break;
 888                        case TOMOYO_MODE_GROUP_WRITE:
 889                                value = S_IWGRP;
 890                                break;
 891                        case TOMOYO_MODE_GROUP_EXECUTE:
 892                                value = S_IXGRP;
 893                                break;
 894                        case TOMOYO_MODE_OTHERS_READ:
 895                                value = S_IROTH;
 896                                break;
 897                        case TOMOYO_MODE_OTHERS_WRITE:
 898                                value = S_IWOTH;
 899                                break;
 900                        case TOMOYO_MODE_OTHERS_EXECUTE:
 901                                value = S_IXOTH;
 902                                break;
 903                        case TOMOYO_EXEC_ARGC:
 904                                if (!bprm)
 905                                        goto out;
 906                                value = bprm->argc;
 907                                break;
 908                        case TOMOYO_EXEC_ENVC:
 909                                if (!bprm)
 910                                        goto out;
 911                                value = bprm->envc;
 912                                break;
 913                        case TOMOYO_NUMBER_UNION:
 914                                /* Fetch values later. */
 915                                break;
 916                        default:
 917                                if (!obj)
 918                                        goto out;
 919                                if (!obj->validate_done) {
 920                                        tomoyo_get_attributes(obj);
 921                                        obj->validate_done = true;
 922                                }
 923                                {
 924                                        u8 stat_index;
 925                                        struct tomoyo_mini_stat *stat;
 926                                        switch (index) {
 927                                        case TOMOYO_PATH1_UID:
 928                                        case TOMOYO_PATH1_GID:
 929                                        case TOMOYO_PATH1_INO:
 930                                        case TOMOYO_PATH1_MAJOR:
 931                                        case TOMOYO_PATH1_MINOR:
 932                                        case TOMOYO_PATH1_TYPE:
 933                                        case TOMOYO_PATH1_DEV_MAJOR:
 934                                        case TOMOYO_PATH1_DEV_MINOR:
 935                                        case TOMOYO_PATH1_PERM:
 936                                                stat_index = TOMOYO_PATH1;
 937                                                break;
 938                                        case TOMOYO_PATH2_UID:
 939                                        case TOMOYO_PATH2_GID:
 940                                        case TOMOYO_PATH2_INO:
 941                                        case TOMOYO_PATH2_MAJOR:
 942                                        case TOMOYO_PATH2_MINOR:
 943                                        case TOMOYO_PATH2_TYPE:
 944                                        case TOMOYO_PATH2_DEV_MAJOR:
 945                                        case TOMOYO_PATH2_DEV_MINOR:
 946                                        case TOMOYO_PATH2_PERM:
 947                                                stat_index = TOMOYO_PATH2;
 948                                                break;
 949                                        case TOMOYO_PATH1_PARENT_UID:
 950                                        case TOMOYO_PATH1_PARENT_GID:
 951                                        case TOMOYO_PATH1_PARENT_INO:
 952                                        case TOMOYO_PATH1_PARENT_PERM:
 953                                                stat_index =
 954                                                        TOMOYO_PATH1_PARENT;
 955                                                break;
 956                                        case TOMOYO_PATH2_PARENT_UID:
 957                                        case TOMOYO_PATH2_PARENT_GID:
 958                                        case TOMOYO_PATH2_PARENT_INO:
 959                                        case TOMOYO_PATH2_PARENT_PERM:
 960                                                stat_index =
 961                                                        TOMOYO_PATH2_PARENT;
 962                                                break;
 963                                        default:
 964                                                goto out;
 965                                        }
 966                                        if (!obj->stat_valid[stat_index])
 967                                                goto out;
 968                                        stat = &obj->stat[stat_index];
 969                                        switch (index) {
 970                                        case TOMOYO_PATH1_UID:
 971                                        case TOMOYO_PATH2_UID:
 972                                        case TOMOYO_PATH1_PARENT_UID:
 973                                        case TOMOYO_PATH2_PARENT_UID:
 974                                                value = from_kuid(&init_user_ns, stat->uid);
 975                                                break;
 976                                        case TOMOYO_PATH1_GID:
 977                                        case TOMOYO_PATH2_GID:
 978                                        case TOMOYO_PATH1_PARENT_GID:
 979                                        case TOMOYO_PATH2_PARENT_GID:
 980                                                value = from_kgid(&init_user_ns, stat->gid);
 981                                                break;
 982                                        case TOMOYO_PATH1_INO:
 983                                        case TOMOYO_PATH2_INO:
 984                                        case TOMOYO_PATH1_PARENT_INO:
 985                                        case TOMOYO_PATH2_PARENT_INO:
 986                                                value = stat->ino;
 987                                                break;
 988                                        case TOMOYO_PATH1_MAJOR:
 989                                        case TOMOYO_PATH2_MAJOR:
 990                                                value = MAJOR(stat->dev);
 991                                                break;
 992                                        case TOMOYO_PATH1_MINOR:
 993                                        case TOMOYO_PATH2_MINOR:
 994                                                value = MINOR(stat->dev);
 995                                                break;
 996                                        case TOMOYO_PATH1_TYPE:
 997                                        case TOMOYO_PATH2_TYPE:
 998                                                value = stat->mode & S_IFMT;
 999                                                break;
1000                                        case TOMOYO_PATH1_DEV_MAJOR:
1001                                        case TOMOYO_PATH2_DEV_MAJOR:
1002                                                value = MAJOR(stat->rdev);
1003                                                break;
1004                                        case TOMOYO_PATH1_DEV_MINOR:
1005                                        case TOMOYO_PATH2_DEV_MINOR:
1006                                                value = MINOR(stat->rdev);
1007                                                break;
1008                                        case TOMOYO_PATH1_PERM:
1009                                        case TOMOYO_PATH2_PERM:
1010                                        case TOMOYO_PATH1_PARENT_PERM:
1011                                        case TOMOYO_PATH2_PARENT_PERM:
1012                                                value = stat->mode & S_IALLUGO;
1013                                                break;
1014                                        }
1015                                }
1016                                break;
1017                        }
1018                        max_v[j] = value;
1019                        min_v[j] = value;
1020                        switch (index) {
1021                        case TOMOYO_MODE_SETUID:
1022                        case TOMOYO_MODE_SETGID:
1023                        case TOMOYO_MODE_STICKY:
1024                        case TOMOYO_MODE_OWNER_READ:
1025                        case TOMOYO_MODE_OWNER_WRITE:
1026                        case TOMOYO_MODE_OWNER_EXECUTE:
1027                        case TOMOYO_MODE_GROUP_READ:
1028                        case TOMOYO_MODE_GROUP_WRITE:
1029                        case TOMOYO_MODE_GROUP_EXECUTE:
1030                        case TOMOYO_MODE_OTHERS_READ:
1031                        case TOMOYO_MODE_OTHERS_WRITE:
1032                        case TOMOYO_MODE_OTHERS_EXECUTE:
1033                                is_bitop[j] = true;
1034                        }
1035                }
1036                if (left == TOMOYO_NUMBER_UNION) {
1037                        /* Fetch values now. */
1038                        const struct tomoyo_number_union *ptr = numbers_p++;
1039                        min_v[0] = ptr->values[0];
1040                        max_v[0] = ptr->values[1];
1041                }
1042                if (right == TOMOYO_NUMBER_UNION) {
1043                        /* Fetch values now. */
1044                        const struct tomoyo_number_union *ptr = numbers_p++;
1045                        if (ptr->group) {
1046                                if (tomoyo_number_matches_group(min_v[0],
1047                                                                max_v[0],
1048                                                                ptr->group)
1049                                    == match)
1050                                        continue;
1051                        } else {
1052                                if ((min_v[0] <= ptr->values[1] &&
1053                                     max_v[0] >= ptr->values[0]) == match)
1054                                        continue;
1055                        }
1056                        goto out;
1057                }
1058                /*
1059                 * Bit operation is valid only when counterpart value
1060                 * represents permission.
1061                 */
1062                if (is_bitop[0] && is_bitop[1]) {
1063                        goto out;
1064                } else if (is_bitop[0]) {
1065                        switch (right) {
1066                        case TOMOYO_PATH1_PERM:
1067                        case TOMOYO_PATH1_PARENT_PERM:
1068                        case TOMOYO_PATH2_PERM:
1069                        case TOMOYO_PATH2_PARENT_PERM:
1070                                if (!(max_v[0] & max_v[1]) == !match)
1071                                        continue;
1072                        }
1073                        goto out;
1074                } else if (is_bitop[1]) {
1075                        switch (left) {
1076                        case TOMOYO_PATH1_PERM:
1077                        case TOMOYO_PATH1_PARENT_PERM:
1078                        case TOMOYO_PATH2_PERM:
1079                        case TOMOYO_PATH2_PARENT_PERM:
1080                                if (!(max_v[0] & max_v[1]) == !match)
1081                                        continue;
1082                        }
1083                        goto out;
1084                }
1085                /* Normal value range comparison. */
1086                if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
1087                        continue;
1088out:
1089                return false;
1090        }
1091        /* Check argv[] and envp[] now. */
1092        if (r->ee && (argc || envc))
1093                return tomoyo_scan_bprm(r->ee, argc, argv, envc, envp);
1094        return true;
1095}
1096