xref: /openbmc/linux/security/tomoyo/condition.c (revision 8730046c)
1 /*
2  * security/tomoyo/condition.c
3  *
4  * Copyright (C) 2005-2011  NTT DATA CORPORATION
5  */
6 
7 #include "common.h"
8 #include <linux/slab.h>
9 
10 /* List of "struct tomoyo_condition". */
11 LIST_HEAD(tomoyo_condition_list);
12 
13 /**
14  * tomoyo_argv - Check argv[] in "struct linux_binbrm".
15  *
16  * @index:   Index number of @arg_ptr.
17  * @arg_ptr: Contents of argv[@index].
18  * @argc:    Length of @argv.
19  * @argv:    Pointer to "struct tomoyo_argv".
20  * @checked: Set to true if @argv[@index] was found.
21  *
22  * Returns true on success, false otherwise.
23  */
24 static bool tomoyo_argv(const unsigned int index, const char *arg_ptr,
25 			const int argc, const struct tomoyo_argv *argv,
26 			u8 *checked)
27 {
28 	int i;
29 	struct tomoyo_path_info arg;
30 	arg.name = arg_ptr;
31 	for (i = 0; i < argc; argv++, checked++, i++) {
32 		bool result;
33 		if (index != argv->index)
34 			continue;
35 		*checked = 1;
36 		tomoyo_fill_path_info(&arg);
37 		result = tomoyo_path_matches_pattern(&arg, argv->value);
38 		if (argv->is_not)
39 			result = !result;
40 		if (!result)
41 			return false;
42 	}
43 	return true;
44 }
45 
46 /**
47  * tomoyo_envp - Check envp[] in "struct linux_binbrm".
48  *
49  * @env_name:  The name of environment variable.
50  * @env_value: The value of environment variable.
51  * @envc:      Length of @envp.
52  * @envp:      Pointer to "struct tomoyo_envp".
53  * @checked:   Set to true if @envp[@env_name] was found.
54  *
55  * Returns true on success, false otherwise.
56  */
57 static bool tomoyo_envp(const char *env_name, const char *env_value,
58 			const int envc, const struct tomoyo_envp *envp,
59 			u8 *checked)
60 {
61 	int i;
62 	struct tomoyo_path_info name;
63 	struct tomoyo_path_info value;
64 	name.name = env_name;
65 	tomoyo_fill_path_info(&name);
66 	value.name = env_value;
67 	tomoyo_fill_path_info(&value);
68 	for (i = 0; i < envc; envp++, checked++, i++) {
69 		bool result;
70 		if (!tomoyo_path_matches_pattern(&name, envp->name))
71 			continue;
72 		*checked = 1;
73 		if (envp->value) {
74 			result = tomoyo_path_matches_pattern(&value,
75 							     envp->value);
76 			if (envp->is_not)
77 				result = !result;
78 		} else {
79 			result = true;
80 			if (!envp->is_not)
81 				result = !result;
82 		}
83 		if (!result)
84 			return false;
85 	}
86 	return true;
87 }
88 
89 /**
90  * tomoyo_scan_bprm - Scan "struct linux_binprm".
91  *
92  * @ee:   Pointer to "struct tomoyo_execve".
93  * @argc: Length of @argc.
94  * @argv: Pointer to "struct tomoyo_argv".
95  * @envc: Length of @envp.
96  * @envp: Poiner to "struct tomoyo_envp".
97  *
98  * Returns true on success, false otherwise.
99  */
100 static bool tomoyo_scan_bprm(struct tomoyo_execve *ee,
101 			     const u16 argc, const struct tomoyo_argv *argv,
102 			     const u16 envc, const struct tomoyo_envp *envp)
103 {
104 	struct linux_binprm *bprm = ee->bprm;
105 	struct tomoyo_page_dump *dump = &ee->dump;
106 	char *arg_ptr = ee->tmp;
107 	int arg_len = 0;
108 	unsigned long pos = bprm->p;
109 	int offset = pos % PAGE_SIZE;
110 	int argv_count = bprm->argc;
111 	int envp_count = bprm->envc;
112 	bool result = true;
113 	u8 local_checked[32];
114 	u8 *checked;
115 	if (argc + envc <= sizeof(local_checked)) {
116 		checked = local_checked;
117 		memset(local_checked, 0, sizeof(local_checked));
118 	} else {
119 		checked = kzalloc(argc + envc, GFP_NOFS);
120 		if (!checked)
121 			return false;
122 	}
123 	while (argv_count || envp_count) {
124 		if (!tomoyo_dump_page(bprm, pos, dump)) {
125 			result = false;
126 			goto out;
127 		}
128 		pos += PAGE_SIZE - offset;
129 		while (offset < PAGE_SIZE) {
130 			/* Read. */
131 			const char *kaddr = dump->data;
132 			const unsigned char c = kaddr[offset++];
133 			if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
134 				if (c == '\\') {
135 					arg_ptr[arg_len++] = '\\';
136 					arg_ptr[arg_len++] = '\\';
137 				} else if (c > ' ' && c < 127) {
138 					arg_ptr[arg_len++] = c;
139 				} else {
140 					arg_ptr[arg_len++] = '\\';
141 					arg_ptr[arg_len++] = (c >> 6) + '0';
142 					arg_ptr[arg_len++] =
143 						((c >> 3) & 7) + '0';
144 					arg_ptr[arg_len++] = (c & 7) + '0';
145 				}
146 			} else {
147 				arg_ptr[arg_len] = '\0';
148 			}
149 			if (c)
150 				continue;
151 			/* Check. */
152 			if (argv_count) {
153 				if (!tomoyo_argv(bprm->argc - argv_count,
154 						 arg_ptr, argc, argv,
155 						 checked)) {
156 					result = false;
157 					break;
158 				}
159 				argv_count--;
160 			} else if (envp_count) {
161 				char *cp = strchr(arg_ptr, '=');
162 				if (cp) {
163 					*cp = '\0';
164 					if (!tomoyo_envp(arg_ptr, cp + 1,
165 							 envc, envp,
166 							 checked + argc)) {
167 						result = false;
168 						break;
169 					}
170 				}
171 				envp_count--;
172 			} else {
173 				break;
174 			}
175 			arg_len = 0;
176 		}
177 		offset = 0;
178 		if (!result)
179 			break;
180 	}
181 out:
182 	if (result) {
183 		int i;
184 		/* Check not-yet-checked entries. */
185 		for (i = 0; i < argc; i++) {
186 			if (checked[i])
187 				continue;
188 			/*
189 			 * Return true only if all unchecked indexes in
190 			 * bprm->argv[] are not matched.
191 			 */
192 			if (argv[i].is_not)
193 				continue;
194 			result = false;
195 			break;
196 		}
197 		for (i = 0; i < envc; envp++, i++) {
198 			if (checked[argc + i])
199 				continue;
200 			/*
201 			 * Return true only if all unchecked environ variables
202 			 * in bprm->envp[] are either undefined or not matched.
203 			 */
204 			if ((!envp->value && !envp->is_not) ||
205 			    (envp->value && envp->is_not))
206 				continue;
207 			result = false;
208 			break;
209 		}
210 	}
211 	if (checked != local_checked)
212 		kfree(checked);
213 	return result;
214 }
215 
216 /**
217  * tomoyo_scan_exec_realpath - Check "exec.realpath" parameter of "struct tomoyo_condition".
218  *
219  * @file:  Pointer to "struct file".
220  * @ptr:   Pointer to "struct tomoyo_name_union".
221  * @match: True if "exec.realpath=", false if "exec.realpath!=".
222  *
223  * Returns true on success, false otherwise.
224  */
225 static bool tomoyo_scan_exec_realpath(struct file *file,
226 				      const struct tomoyo_name_union *ptr,
227 				      const bool match)
228 {
229 	bool result;
230 	struct tomoyo_path_info exe;
231 	if (!file)
232 		return false;
233 	exe.name = tomoyo_realpath_from_path(&file->f_path);
234 	if (!exe.name)
235 		return false;
236 	tomoyo_fill_path_info(&exe);
237 	result = tomoyo_compare_name_union(&exe, ptr);
238 	kfree(exe.name);
239 	return result == match;
240 }
241 
242 /**
243  * tomoyo_get_dqword - tomoyo_get_name() for a quoted string.
244  *
245  * @start: String to save.
246  *
247  * Returns pointer to "struct tomoyo_path_info" on success, NULL otherwise.
248  */
249 static const struct tomoyo_path_info *tomoyo_get_dqword(char *start)
250 {
251 	char *cp = start + strlen(start) - 1;
252 	if (cp == start || *start++ != '"' || *cp != '"')
253 		return NULL;
254 	*cp = '\0';
255 	if (*start && !tomoyo_correct_word(start))
256 		return NULL;
257 	return tomoyo_get_name(start);
258 }
259 
260 /**
261  * tomoyo_parse_name_union_quoted - Parse a quoted word.
262  *
263  * @param: Pointer to "struct tomoyo_acl_param".
264  * @ptr:   Pointer to "struct tomoyo_name_union".
265  *
266  * Returns true on success, false otherwise.
267  */
268 static bool tomoyo_parse_name_union_quoted(struct tomoyo_acl_param *param,
269 					   struct tomoyo_name_union *ptr)
270 {
271 	char *filename = param->data;
272 	if (*filename == '@')
273 		return tomoyo_parse_name_union(param, ptr);
274 	ptr->filename = tomoyo_get_dqword(filename);
275 	return ptr->filename != NULL;
276 }
277 
278 /**
279  * tomoyo_parse_argv - Parse an argv[] condition part.
280  *
281  * @left:  Lefthand value.
282  * @right: Righthand value.
283  * @argv:  Pointer to "struct tomoyo_argv".
284  *
285  * Returns true on success, false otherwise.
286  */
287 static bool tomoyo_parse_argv(char *left, char *right,
288 			      struct tomoyo_argv *argv)
289 {
290 	if (tomoyo_parse_ulong(&argv->index, &left) !=
291 	    TOMOYO_VALUE_TYPE_DECIMAL || *left++ != ']' || *left)
292 		return false;
293 	argv->value = tomoyo_get_dqword(right);
294 	return argv->value != NULL;
295 }
296 
297 /**
298  * tomoyo_parse_envp - Parse an envp[] condition part.
299  *
300  * @left:  Lefthand value.
301  * @right: Righthand value.
302  * @envp:  Pointer to "struct tomoyo_envp".
303  *
304  * Returns true on success, false otherwise.
305  */
306 static bool tomoyo_parse_envp(char *left, char *right,
307 			      struct tomoyo_envp *envp)
308 {
309 	const struct tomoyo_path_info *name;
310 	const struct tomoyo_path_info *value;
311 	char *cp = left + strlen(left) - 1;
312 	if (*cp-- != ']' || *cp != '"')
313 		goto out;
314 	*cp = '\0';
315 	if (!tomoyo_correct_word(left))
316 		goto out;
317 	name = tomoyo_get_name(left);
318 	if (!name)
319 		goto out;
320 	if (!strcmp(right, "NULL")) {
321 		value = NULL;
322 	} else {
323 		value = tomoyo_get_dqword(right);
324 		if (!value) {
325 			tomoyo_put_name(name);
326 			goto out;
327 		}
328 	}
329 	envp->name = name;
330 	envp->value = value;
331 	return true;
332 out:
333 	return false;
334 }
335 
336 /**
337  * tomoyo_same_condition - Check for duplicated "struct tomoyo_condition" entry.
338  *
339  * @a: Pointer to "struct tomoyo_condition".
340  * @b: Pointer to "struct tomoyo_condition".
341  *
342  * Returns true if @a == @b, false otherwise.
343  */
344 static inline bool tomoyo_same_condition(const struct tomoyo_condition *a,
345 					 const struct tomoyo_condition *b)
346 {
347 	return a->size == b->size && a->condc == b->condc &&
348 		a->numbers_count == b->numbers_count &&
349 		a->names_count == b->names_count &&
350 		a->argc == b->argc && a->envc == b->envc &&
351 		a->grant_log == b->grant_log && a->transit == b->transit &&
352 		!memcmp(a + 1, b + 1, a->size - sizeof(*a));
353 }
354 
355 /**
356  * tomoyo_condition_type - Get condition type.
357  *
358  * @word: Keyword string.
359  *
360  * Returns one of values in "enum tomoyo_conditions_index" on success,
361  * TOMOYO_MAX_CONDITION_KEYWORD otherwise.
362  */
363 static u8 tomoyo_condition_type(const char *word)
364 {
365 	u8 i;
366 	for (i = 0; i < TOMOYO_MAX_CONDITION_KEYWORD; i++) {
367 		if (!strcmp(word, tomoyo_condition_keyword[i]))
368 			break;
369 	}
370 	return i;
371 }
372 
373 /* Define this to enable debug mode. */
374 /* #define DEBUG_CONDITION */
375 
376 #ifdef DEBUG_CONDITION
377 #define dprintk printk
378 #else
379 #define dprintk(...) do { } while (0)
380 #endif
381 
382 /**
383  * tomoyo_commit_condition - Commit "struct tomoyo_condition".
384  *
385  * @entry: Pointer to "struct tomoyo_condition".
386  *
387  * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
388  *
389  * This function merges duplicated entries. This function returns NULL if
390  * @entry is not duplicated but memory quota for policy has exceeded.
391  */
392 static struct tomoyo_condition *tomoyo_commit_condition
393 (struct tomoyo_condition *entry)
394 {
395 	struct tomoyo_condition *ptr;
396 	bool found = false;
397 	if (mutex_lock_interruptible(&tomoyo_policy_lock)) {
398 		dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
399 		ptr = NULL;
400 		found = true;
401 		goto out;
402 	}
403 	list_for_each_entry(ptr, &tomoyo_condition_list, head.list) {
404 		if (!tomoyo_same_condition(ptr, entry) ||
405 		    atomic_read(&ptr->head.users) == TOMOYO_GC_IN_PROGRESS)
406 			continue;
407 		/* Same entry found. Share this entry. */
408 		atomic_inc(&ptr->head.users);
409 		found = true;
410 		break;
411 	}
412 	if (!found) {
413 		if (tomoyo_memory_ok(entry)) {
414 			atomic_set(&entry->head.users, 1);
415 			list_add(&entry->head.list, &tomoyo_condition_list);
416 		} else {
417 			found = true;
418 			ptr = NULL;
419 		}
420 	}
421 	mutex_unlock(&tomoyo_policy_lock);
422 out:
423 	if (found) {
424 		tomoyo_del_condition(&entry->head.list);
425 		kfree(entry);
426 		entry = ptr;
427 	}
428 	return entry;
429 }
430 
431 /**
432  * tomoyo_get_transit_preference - Parse domain transition preference for execve().
433  *
434  * @param: Pointer to "struct tomoyo_acl_param".
435  * @e:     Pointer to "struct tomoyo_condition".
436  *
437  * Returns the condition string part.
438  */
439 static char *tomoyo_get_transit_preference(struct tomoyo_acl_param *param,
440 					   struct tomoyo_condition *e)
441 {
442 	char * const pos = param->data;
443 	bool flag;
444 	if (*pos == '<') {
445 		e->transit = tomoyo_get_domainname(param);
446 		goto done;
447 	}
448 	{
449 		char *cp = strchr(pos, ' ');
450 		if (cp)
451 			*cp = '\0';
452 		flag = tomoyo_correct_path(pos) || !strcmp(pos, "keep") ||
453 			!strcmp(pos, "initialize") || !strcmp(pos, "reset") ||
454 			!strcmp(pos, "child") || !strcmp(pos, "parent");
455 		if (cp)
456 			*cp = ' ';
457 	}
458 	if (!flag)
459 		return pos;
460 	e->transit = tomoyo_get_name(tomoyo_read_token(param));
461 done:
462 	if (e->transit)
463 		return param->data;
464 	/*
465 	 * Return a bad read-only condition string that will let
466 	 * tomoyo_get_condition() return NULL.
467 	 */
468 	return "/";
469 }
470 
471 /**
472  * tomoyo_get_condition - Parse condition part.
473  *
474  * @param: Pointer to "struct tomoyo_acl_param".
475  *
476  * Returns pointer to "struct tomoyo_condition" on success, NULL otherwise.
477  */
478 struct tomoyo_condition *tomoyo_get_condition(struct tomoyo_acl_param *param)
479 {
480 	struct tomoyo_condition *entry = NULL;
481 	struct tomoyo_condition_element *condp = NULL;
482 	struct tomoyo_number_union *numbers_p = NULL;
483 	struct tomoyo_name_union *names_p = NULL;
484 	struct tomoyo_argv *argv = NULL;
485 	struct tomoyo_envp *envp = NULL;
486 	struct tomoyo_condition e = { };
487 	char * const start_of_string =
488 		tomoyo_get_transit_preference(param, &e);
489 	char * const end_of_string = start_of_string + strlen(start_of_string);
490 	char *pos;
491 rerun:
492 	pos = start_of_string;
493 	while (1) {
494 		u8 left = -1;
495 		u8 right = -1;
496 		char *left_word = pos;
497 		char *cp;
498 		char *right_word;
499 		bool is_not;
500 		if (!*left_word)
501 			break;
502 		/*
503 		 * Since left-hand condition does not allow use of "path_group"
504 		 * or "number_group" and environment variable's names do not
505 		 * accept '=', it is guaranteed that the original line consists
506 		 * of one or more repetition of $left$operator$right blocks
507 		 * where "$left is free from '=' and ' '" and "$operator is
508 		 * either '=' or '!='" and "$right is free from ' '".
509 		 * Therefore, we can reconstruct the original line at the end
510 		 * of dry run even if we overwrite $operator with '\0'.
511 		 */
512 		cp = strchr(pos, ' ');
513 		if (cp) {
514 			*cp = '\0'; /* Will restore later. */
515 			pos = cp + 1;
516 		} else {
517 			pos = "";
518 		}
519 		right_word = strchr(left_word, '=');
520 		if (!right_word || right_word == left_word)
521 			goto out;
522 		is_not = *(right_word - 1) == '!';
523 		if (is_not)
524 			*(right_word++ - 1) = '\0'; /* Will restore later. */
525 		else if (*(right_word + 1) != '=')
526 			*right_word++ = '\0'; /* Will restore later. */
527 		else
528 			goto out;
529 		dprintk(KERN_WARNING "%u: <%s>%s=<%s>\n", __LINE__, left_word,
530 			is_not ? "!" : "", right_word);
531 		if (!strcmp(left_word, "grant_log")) {
532 			if (entry) {
533 				if (is_not ||
534 				    entry->grant_log != TOMOYO_GRANTLOG_AUTO)
535 					goto out;
536 				else if (!strcmp(right_word, "yes"))
537 					entry->grant_log = TOMOYO_GRANTLOG_YES;
538 				else if (!strcmp(right_word, "no"))
539 					entry->grant_log = TOMOYO_GRANTLOG_NO;
540 				else
541 					goto out;
542 			}
543 			continue;
544 		}
545 		if (!strncmp(left_word, "exec.argv[", 10)) {
546 			if (!argv) {
547 				e.argc++;
548 				e.condc++;
549 			} else {
550 				e.argc--;
551 				e.condc--;
552 				left = TOMOYO_ARGV_ENTRY;
553 				argv->is_not = is_not;
554 				if (!tomoyo_parse_argv(left_word + 10,
555 						       right_word, argv++))
556 					goto out;
557 			}
558 			goto store_value;
559 		}
560 		if (!strncmp(left_word, "exec.envp[\"", 11)) {
561 			if (!envp) {
562 				e.envc++;
563 				e.condc++;
564 			} else {
565 				e.envc--;
566 				e.condc--;
567 				left = TOMOYO_ENVP_ENTRY;
568 				envp->is_not = is_not;
569 				if (!tomoyo_parse_envp(left_word + 11,
570 						       right_word, envp++))
571 					goto out;
572 			}
573 			goto store_value;
574 		}
575 		left = tomoyo_condition_type(left_word);
576 		dprintk(KERN_WARNING "%u: <%s> left=%u\n", __LINE__, left_word,
577 			left);
578 		if (left == TOMOYO_MAX_CONDITION_KEYWORD) {
579 			if (!numbers_p) {
580 				e.numbers_count++;
581 			} else {
582 				e.numbers_count--;
583 				left = TOMOYO_NUMBER_UNION;
584 				param->data = left_word;
585 				if (*left_word == '@' ||
586 				    !tomoyo_parse_number_union(param,
587 							       numbers_p++))
588 					goto out;
589 			}
590 		}
591 		if (!condp)
592 			e.condc++;
593 		else
594 			e.condc--;
595 		if (left == TOMOYO_EXEC_REALPATH ||
596 		    left == TOMOYO_SYMLINK_TARGET) {
597 			if (!names_p) {
598 				e.names_count++;
599 			} else {
600 				e.names_count--;
601 				right = TOMOYO_NAME_UNION;
602 				param->data = right_word;
603 				if (!tomoyo_parse_name_union_quoted(param,
604 								    names_p++))
605 					goto out;
606 			}
607 			goto store_value;
608 		}
609 		right = tomoyo_condition_type(right_word);
610 		if (right == TOMOYO_MAX_CONDITION_KEYWORD) {
611 			if (!numbers_p) {
612 				e.numbers_count++;
613 			} else {
614 				e.numbers_count--;
615 				right = TOMOYO_NUMBER_UNION;
616 				param->data = right_word;
617 				if (!tomoyo_parse_number_union(param,
618 							       numbers_p++))
619 					goto out;
620 			}
621 		}
622 store_value:
623 		if (!condp) {
624 			dprintk(KERN_WARNING "%u: dry_run left=%u right=%u "
625 				"match=%u\n", __LINE__, left, right, !is_not);
626 			continue;
627 		}
628 		condp->left = left;
629 		condp->right = right;
630 		condp->equals = !is_not;
631 		dprintk(KERN_WARNING "%u: left=%u right=%u match=%u\n",
632 			__LINE__, condp->left, condp->right,
633 			condp->equals);
634 		condp++;
635 	}
636 	dprintk(KERN_INFO "%u: cond=%u numbers=%u names=%u ac=%u ec=%u\n",
637 		__LINE__, e.condc, e.numbers_count, e.names_count, e.argc,
638 		e.envc);
639 	if (entry) {
640 		BUG_ON(e.names_count | e.numbers_count | e.argc | e.envc |
641 		       e.condc);
642 		return tomoyo_commit_condition(entry);
643 	}
644 	e.size = sizeof(*entry)
645 		+ e.condc * sizeof(struct tomoyo_condition_element)
646 		+ e.numbers_count * sizeof(struct tomoyo_number_union)
647 		+ e.names_count * sizeof(struct tomoyo_name_union)
648 		+ e.argc * sizeof(struct tomoyo_argv)
649 		+ e.envc * sizeof(struct tomoyo_envp);
650 	entry = kzalloc(e.size, GFP_NOFS);
651 	if (!entry)
652 		goto out2;
653 	*entry = e;
654 	e.transit = NULL;
655 	condp = (struct tomoyo_condition_element *) (entry + 1);
656 	numbers_p = (struct tomoyo_number_union *) (condp + e.condc);
657 	names_p = (struct tomoyo_name_union *) (numbers_p + e.numbers_count);
658 	argv = (struct tomoyo_argv *) (names_p + e.names_count);
659 	envp = (struct tomoyo_envp *) (argv + e.argc);
660 	{
661 		bool flag = false;
662 		for (pos = start_of_string; pos < end_of_string; pos++) {
663 			if (*pos)
664 				continue;
665 			if (flag) /* Restore " ". */
666 				*pos = ' ';
667 			else if (*(pos + 1) == '=') /* Restore "!=". */
668 				*pos = '!';
669 			else /* Restore "=". */
670 				*pos = '=';
671 			flag = !flag;
672 		}
673 	}
674 	goto rerun;
675 out:
676 	dprintk(KERN_WARNING "%u: %s failed\n", __LINE__, __func__);
677 	if (entry) {
678 		tomoyo_del_condition(&entry->head.list);
679 		kfree(entry);
680 	}
681 out2:
682 	tomoyo_put_name(e.transit);
683 	return NULL;
684 }
685 
686 /**
687  * tomoyo_get_attributes - Revalidate "struct inode".
688  *
689  * @obj: Pointer to "struct tomoyo_obj_info".
690  *
691  * Returns nothing.
692  */
693 void tomoyo_get_attributes(struct tomoyo_obj_info *obj)
694 {
695 	u8 i;
696 	struct dentry *dentry = NULL;
697 
698 	for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
699 		struct inode *inode;
700 		switch (i) {
701 		case TOMOYO_PATH1:
702 			dentry = obj->path1.dentry;
703 			if (!dentry)
704 				continue;
705 			break;
706 		case TOMOYO_PATH2:
707 			dentry = obj->path2.dentry;
708 			if (!dentry)
709 				continue;
710 			break;
711 		default:
712 			if (!dentry)
713 				continue;
714 			dentry = dget_parent(dentry);
715 			break;
716 		}
717 		inode = d_backing_inode(dentry);
718 		if (inode) {
719 			struct tomoyo_mini_stat *stat = &obj->stat[i];
720 			stat->uid  = inode->i_uid;
721 			stat->gid  = inode->i_gid;
722 			stat->ino  = inode->i_ino;
723 			stat->mode = inode->i_mode;
724 			stat->dev  = inode->i_sb->s_dev;
725 			stat->rdev = inode->i_rdev;
726 			obj->stat_valid[i] = true;
727 		}
728 		if (i & 1) /* i == TOMOYO_PATH1_PARENT ||
729 			      i == TOMOYO_PATH2_PARENT */
730 			dput(dentry);
731 	}
732 }
733 
734 /**
735  * tomoyo_condition - Check condition part.
736  *
737  * @r:    Pointer to "struct tomoyo_request_info".
738  * @cond: Pointer to "struct tomoyo_condition". Maybe NULL.
739  *
740  * Returns true on success, false otherwise.
741  *
742  * Caller holds tomoyo_read_lock().
743  */
744 bool tomoyo_condition(struct tomoyo_request_info *r,
745 		      const struct tomoyo_condition *cond)
746 {
747 	u32 i;
748 	unsigned long min_v[2] = { 0, 0 };
749 	unsigned long max_v[2] = { 0, 0 };
750 	const struct tomoyo_condition_element *condp;
751 	const struct tomoyo_number_union *numbers_p;
752 	const struct tomoyo_name_union *names_p;
753 	const struct tomoyo_argv *argv;
754 	const struct tomoyo_envp *envp;
755 	struct tomoyo_obj_info *obj;
756 	u16 condc;
757 	u16 argc;
758 	u16 envc;
759 	struct linux_binprm *bprm = NULL;
760 	if (!cond)
761 		return true;
762 	condc = cond->condc;
763 	argc = cond->argc;
764 	envc = cond->envc;
765 	obj = r->obj;
766 	if (r->ee)
767 		bprm = r->ee->bprm;
768 	if (!bprm && (argc || envc))
769 		return false;
770 	condp = (struct tomoyo_condition_element *) (cond + 1);
771 	numbers_p = (const struct tomoyo_number_union *) (condp + condc);
772 	names_p = (const struct tomoyo_name_union *)
773 		(numbers_p + cond->numbers_count);
774 	argv = (const struct tomoyo_argv *) (names_p + cond->names_count);
775 	envp = (const struct tomoyo_envp *) (argv + argc);
776 	for (i = 0; i < condc; i++) {
777 		const bool match = condp->equals;
778 		const u8 left = condp->left;
779 		const u8 right = condp->right;
780 		bool is_bitop[2] = { false, false };
781 		u8 j;
782 		condp++;
783 		/* Check argv[] and envp[] later. */
784 		if (left == TOMOYO_ARGV_ENTRY || left == TOMOYO_ENVP_ENTRY)
785 			continue;
786 		/* Check string expressions. */
787 		if (right == TOMOYO_NAME_UNION) {
788 			const struct tomoyo_name_union *ptr = names_p++;
789 			switch (left) {
790 				struct tomoyo_path_info *symlink;
791 				struct tomoyo_execve *ee;
792 				struct file *file;
793 			case TOMOYO_SYMLINK_TARGET:
794 				symlink = obj ? obj->symlink_target : NULL;
795 				if (!symlink ||
796 				    !tomoyo_compare_name_union(symlink, ptr)
797 				    == match)
798 					goto out;
799 				break;
800 			case TOMOYO_EXEC_REALPATH:
801 				ee = r->ee;
802 				file = ee ? ee->bprm->file : NULL;
803 				if (!tomoyo_scan_exec_realpath(file, ptr,
804 							       match))
805 					goto out;
806 				break;
807 			}
808 			continue;
809 		}
810 		/* Check numeric or bit-op expressions. */
811 		for (j = 0; j < 2; j++) {
812 			const u8 index = j ? right : left;
813 			unsigned long value = 0;
814 			switch (index) {
815 			case TOMOYO_TASK_UID:
816 				value = from_kuid(&init_user_ns, current_uid());
817 				break;
818 			case TOMOYO_TASK_EUID:
819 				value = from_kuid(&init_user_ns, current_euid());
820 				break;
821 			case TOMOYO_TASK_SUID:
822 				value = from_kuid(&init_user_ns, current_suid());
823 				break;
824 			case TOMOYO_TASK_FSUID:
825 				value = from_kuid(&init_user_ns, current_fsuid());
826 				break;
827 			case TOMOYO_TASK_GID:
828 				value = from_kgid(&init_user_ns, current_gid());
829 				break;
830 			case TOMOYO_TASK_EGID:
831 				value = from_kgid(&init_user_ns, current_egid());
832 				break;
833 			case TOMOYO_TASK_SGID:
834 				value = from_kgid(&init_user_ns, current_sgid());
835 				break;
836 			case TOMOYO_TASK_FSGID:
837 				value = from_kgid(&init_user_ns, current_fsgid());
838 				break;
839 			case TOMOYO_TASK_PID:
840 				value = tomoyo_sys_getpid();
841 				break;
842 			case TOMOYO_TASK_PPID:
843 				value = tomoyo_sys_getppid();
844 				break;
845 			case TOMOYO_TYPE_IS_SOCKET:
846 				value = S_IFSOCK;
847 				break;
848 			case TOMOYO_TYPE_IS_SYMLINK:
849 				value = S_IFLNK;
850 				break;
851 			case TOMOYO_TYPE_IS_FILE:
852 				value = S_IFREG;
853 				break;
854 			case TOMOYO_TYPE_IS_BLOCK_DEV:
855 				value = S_IFBLK;
856 				break;
857 			case TOMOYO_TYPE_IS_DIRECTORY:
858 				value = S_IFDIR;
859 				break;
860 			case TOMOYO_TYPE_IS_CHAR_DEV:
861 				value = S_IFCHR;
862 				break;
863 			case TOMOYO_TYPE_IS_FIFO:
864 				value = S_IFIFO;
865 				break;
866 			case TOMOYO_MODE_SETUID:
867 				value = S_ISUID;
868 				break;
869 			case TOMOYO_MODE_SETGID:
870 				value = S_ISGID;
871 				break;
872 			case TOMOYO_MODE_STICKY:
873 				value = S_ISVTX;
874 				break;
875 			case TOMOYO_MODE_OWNER_READ:
876 				value = S_IRUSR;
877 				break;
878 			case TOMOYO_MODE_OWNER_WRITE:
879 				value = S_IWUSR;
880 				break;
881 			case TOMOYO_MODE_OWNER_EXECUTE:
882 				value = S_IXUSR;
883 				break;
884 			case TOMOYO_MODE_GROUP_READ:
885 				value = S_IRGRP;
886 				break;
887 			case TOMOYO_MODE_GROUP_WRITE:
888 				value = S_IWGRP;
889 				break;
890 			case TOMOYO_MODE_GROUP_EXECUTE:
891 				value = S_IXGRP;
892 				break;
893 			case TOMOYO_MODE_OTHERS_READ:
894 				value = S_IROTH;
895 				break;
896 			case TOMOYO_MODE_OTHERS_WRITE:
897 				value = S_IWOTH;
898 				break;
899 			case TOMOYO_MODE_OTHERS_EXECUTE:
900 				value = S_IXOTH;
901 				break;
902 			case TOMOYO_EXEC_ARGC:
903 				if (!bprm)
904 					goto out;
905 				value = bprm->argc;
906 				break;
907 			case TOMOYO_EXEC_ENVC:
908 				if (!bprm)
909 					goto out;
910 				value = bprm->envc;
911 				break;
912 			case TOMOYO_NUMBER_UNION:
913 				/* Fetch values later. */
914 				break;
915 			default:
916 				if (!obj)
917 					goto out;
918 				if (!obj->validate_done) {
919 					tomoyo_get_attributes(obj);
920 					obj->validate_done = true;
921 				}
922 				{
923 					u8 stat_index;
924 					struct tomoyo_mini_stat *stat;
925 					switch (index) {
926 					case TOMOYO_PATH1_UID:
927 					case TOMOYO_PATH1_GID:
928 					case TOMOYO_PATH1_INO:
929 					case TOMOYO_PATH1_MAJOR:
930 					case TOMOYO_PATH1_MINOR:
931 					case TOMOYO_PATH1_TYPE:
932 					case TOMOYO_PATH1_DEV_MAJOR:
933 					case TOMOYO_PATH1_DEV_MINOR:
934 					case TOMOYO_PATH1_PERM:
935 						stat_index = TOMOYO_PATH1;
936 						break;
937 					case TOMOYO_PATH2_UID:
938 					case TOMOYO_PATH2_GID:
939 					case TOMOYO_PATH2_INO:
940 					case TOMOYO_PATH2_MAJOR:
941 					case TOMOYO_PATH2_MINOR:
942 					case TOMOYO_PATH2_TYPE:
943 					case TOMOYO_PATH2_DEV_MAJOR:
944 					case TOMOYO_PATH2_DEV_MINOR:
945 					case TOMOYO_PATH2_PERM:
946 						stat_index = TOMOYO_PATH2;
947 						break;
948 					case TOMOYO_PATH1_PARENT_UID:
949 					case TOMOYO_PATH1_PARENT_GID:
950 					case TOMOYO_PATH1_PARENT_INO:
951 					case TOMOYO_PATH1_PARENT_PERM:
952 						stat_index =
953 							TOMOYO_PATH1_PARENT;
954 						break;
955 					case TOMOYO_PATH2_PARENT_UID:
956 					case TOMOYO_PATH2_PARENT_GID:
957 					case TOMOYO_PATH2_PARENT_INO:
958 					case TOMOYO_PATH2_PARENT_PERM:
959 						stat_index =
960 							TOMOYO_PATH2_PARENT;
961 						break;
962 					default:
963 						goto out;
964 					}
965 					if (!obj->stat_valid[stat_index])
966 						goto out;
967 					stat = &obj->stat[stat_index];
968 					switch (index) {
969 					case TOMOYO_PATH1_UID:
970 					case TOMOYO_PATH2_UID:
971 					case TOMOYO_PATH1_PARENT_UID:
972 					case TOMOYO_PATH2_PARENT_UID:
973 						value = from_kuid(&init_user_ns, stat->uid);
974 						break;
975 					case TOMOYO_PATH1_GID:
976 					case TOMOYO_PATH2_GID:
977 					case TOMOYO_PATH1_PARENT_GID:
978 					case TOMOYO_PATH2_PARENT_GID:
979 						value = from_kgid(&init_user_ns, stat->gid);
980 						break;
981 					case TOMOYO_PATH1_INO:
982 					case TOMOYO_PATH2_INO:
983 					case TOMOYO_PATH1_PARENT_INO:
984 					case TOMOYO_PATH2_PARENT_INO:
985 						value = stat->ino;
986 						break;
987 					case TOMOYO_PATH1_MAJOR:
988 					case TOMOYO_PATH2_MAJOR:
989 						value = MAJOR(stat->dev);
990 						break;
991 					case TOMOYO_PATH1_MINOR:
992 					case TOMOYO_PATH2_MINOR:
993 						value = MINOR(stat->dev);
994 						break;
995 					case TOMOYO_PATH1_TYPE:
996 					case TOMOYO_PATH2_TYPE:
997 						value = stat->mode & S_IFMT;
998 						break;
999 					case TOMOYO_PATH1_DEV_MAJOR:
1000 					case TOMOYO_PATH2_DEV_MAJOR:
1001 						value = MAJOR(stat->rdev);
1002 						break;
1003 					case TOMOYO_PATH1_DEV_MINOR:
1004 					case TOMOYO_PATH2_DEV_MINOR:
1005 						value = MINOR(stat->rdev);
1006 						break;
1007 					case TOMOYO_PATH1_PERM:
1008 					case TOMOYO_PATH2_PERM:
1009 					case TOMOYO_PATH1_PARENT_PERM:
1010 					case TOMOYO_PATH2_PARENT_PERM:
1011 						value = stat->mode & S_IALLUGO;
1012 						break;
1013 					}
1014 				}
1015 				break;
1016 			}
1017 			max_v[j] = value;
1018 			min_v[j] = value;
1019 			switch (index) {
1020 			case TOMOYO_MODE_SETUID:
1021 			case TOMOYO_MODE_SETGID:
1022 			case TOMOYO_MODE_STICKY:
1023 			case TOMOYO_MODE_OWNER_READ:
1024 			case TOMOYO_MODE_OWNER_WRITE:
1025 			case TOMOYO_MODE_OWNER_EXECUTE:
1026 			case TOMOYO_MODE_GROUP_READ:
1027 			case TOMOYO_MODE_GROUP_WRITE:
1028 			case TOMOYO_MODE_GROUP_EXECUTE:
1029 			case TOMOYO_MODE_OTHERS_READ:
1030 			case TOMOYO_MODE_OTHERS_WRITE:
1031 			case TOMOYO_MODE_OTHERS_EXECUTE:
1032 				is_bitop[j] = true;
1033 			}
1034 		}
1035 		if (left == TOMOYO_NUMBER_UNION) {
1036 			/* Fetch values now. */
1037 			const struct tomoyo_number_union *ptr = numbers_p++;
1038 			min_v[0] = ptr->values[0];
1039 			max_v[0] = ptr->values[1];
1040 		}
1041 		if (right == TOMOYO_NUMBER_UNION) {
1042 			/* Fetch values now. */
1043 			const struct tomoyo_number_union *ptr = numbers_p++;
1044 			if (ptr->group) {
1045 				if (tomoyo_number_matches_group(min_v[0],
1046 								max_v[0],
1047 								ptr->group)
1048 				    == match)
1049 					continue;
1050 			} else {
1051 				if ((min_v[0] <= ptr->values[1] &&
1052 				     max_v[0] >= ptr->values[0]) == match)
1053 					continue;
1054 			}
1055 			goto out;
1056 		}
1057 		/*
1058 		 * Bit operation is valid only when counterpart value
1059 		 * represents permission.
1060 		 */
1061 		if (is_bitop[0] && is_bitop[1]) {
1062 			goto out;
1063 		} else if (is_bitop[0]) {
1064 			switch (right) {
1065 			case TOMOYO_PATH1_PERM:
1066 			case TOMOYO_PATH1_PARENT_PERM:
1067 			case TOMOYO_PATH2_PERM:
1068 			case TOMOYO_PATH2_PARENT_PERM:
1069 				if (!(max_v[0] & max_v[1]) == !match)
1070 					continue;
1071 			}
1072 			goto out;
1073 		} else if (is_bitop[1]) {
1074 			switch (left) {
1075 			case TOMOYO_PATH1_PERM:
1076 			case TOMOYO_PATH1_PARENT_PERM:
1077 			case TOMOYO_PATH2_PERM:
1078 			case TOMOYO_PATH2_PARENT_PERM:
1079 				if (!(max_v[0] & max_v[1]) == !match)
1080 					continue;
1081 			}
1082 			goto out;
1083 		}
1084 		/* Normal value range comparison. */
1085 		if ((min_v[0] <= max_v[1] && max_v[0] >= min_v[1]) == match)
1086 			continue;
1087 out:
1088 		return false;
1089 	}
1090 	/* Check argv[] and envp[] now. */
1091 	if (r->ee && (argc || envc))
1092 		return tomoyo_scan_bprm(r->ee, argc, argv, envc, envp);
1093 	return true;
1094 }
1095