xref: /openbmc/linux/security/tomoyo/condition.c (revision e639c869)
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". */
12 LIST_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  */
25 static 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  */
58 static 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  */
101 static 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 	}
182 out:
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  */
226 static 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  */
250 static 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  */
269 static 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  */
288 static 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  */
307 static 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;
333 out:
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  */
345 static 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  */
364 static 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  */
393 static 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);
423 out:
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  */
440 static 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));
462 done:
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  */
479 struct 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;
492 rerun:
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 		}
623 store_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;
676 out:
677 	dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
678 	if (entry) {
679 		tomoyo_del_condition(&entry->head.list);
680 		kfree(entry);
681 	}
682 out2:
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  */
694 void 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  */
745 bool 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;
1088 out:
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