1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * security/tomoyo/domain.c
4 *
5 * Copyright (C) 2005-2011 NTT DATA CORPORATION
6 */
7
8 #include "common.h"
9
10 #include <linux/binfmts.h>
11 #include <linux/slab.h>
12 #include <linux/rculist.h>
13
14 /* Variables definitions.*/
15
16 /* The initial domain. */
17 struct tomoyo_domain_info tomoyo_kernel_domain;
18
19 /**
20 * tomoyo_update_policy - Update an entry for exception policy.
21 *
22 * @new_entry: Pointer to "struct tomoyo_acl_info".
23 * @size: Size of @new_entry in bytes.
24 * @param: Pointer to "struct tomoyo_acl_param".
25 * @check_duplicate: Callback function to find duplicated entry.
26 *
27 * Returns 0 on success, negative value otherwise.
28 *
29 * Caller holds tomoyo_read_lock().
30 */
31 int tomoyo_update_policy(struct tomoyo_acl_head *new_entry, const int size,
32 struct tomoyo_acl_param *param,
33 bool (*check_duplicate)(const struct tomoyo_acl_head
34 *,
35 const struct tomoyo_acl_head
36 *))
37 {
38 int error = param->is_delete ? -ENOENT : -ENOMEM;
39 struct tomoyo_acl_head *entry;
40 struct list_head *list = param->list;
41
42 if (mutex_lock_interruptible(&tomoyo_policy_lock))
43 return -ENOMEM;
44 list_for_each_entry_rcu(entry, list, list,
45 srcu_read_lock_held(&tomoyo_ss)) {
46 if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
47 continue;
48 if (!check_duplicate(entry, new_entry))
49 continue;
50 entry->is_deleted = param->is_delete;
51 error = 0;
52 break;
53 }
54 if (error && !param->is_delete) {
55 entry = tomoyo_commit_ok(new_entry, size);
56 if (entry) {
57 list_add_tail_rcu(&entry->list, list);
58 error = 0;
59 }
60 }
61 mutex_unlock(&tomoyo_policy_lock);
62 return error;
63 }
64
65 /**
66 * tomoyo_same_acl_head - Check for duplicated "struct tomoyo_acl_info" entry.
67 *
68 * @a: Pointer to "struct tomoyo_acl_info".
69 * @b: Pointer to "struct tomoyo_acl_info".
70 *
71 * Returns true if @a == @b, false otherwise.
72 */
73 static inline bool tomoyo_same_acl_head(const struct tomoyo_acl_info *a,
74 const struct tomoyo_acl_info *b)
75 {
76 return a->type == b->type && a->cond == b->cond;
77 }
78
79 /**
80 * tomoyo_update_domain - Update an entry for domain policy.
81 *
82 * @new_entry: Pointer to "struct tomoyo_acl_info".
83 * @size: Size of @new_entry in bytes.
84 * @param: Pointer to "struct tomoyo_acl_param".
85 * @check_duplicate: Callback function to find duplicated entry.
86 * @merge_duplicate: Callback function to merge duplicated entry.
87 *
88 * Returns 0 on success, negative value otherwise.
89 *
90 * Caller holds tomoyo_read_lock().
91 */
92 int tomoyo_update_domain(struct tomoyo_acl_info *new_entry, const int size,
93 struct tomoyo_acl_param *param,
94 bool (*check_duplicate)(const struct tomoyo_acl_info
95 *,
96 const struct tomoyo_acl_info
97 *),
98 bool (*merge_duplicate)(struct tomoyo_acl_info *,
99 struct tomoyo_acl_info *,
100 const bool))
101 {
102 const bool is_delete = param->is_delete;
103 int error = is_delete ? -ENOENT : -ENOMEM;
104 struct tomoyo_acl_info *entry;
105 struct list_head * const list = param->list;
106
107 if (param->data[0]) {
108 new_entry->cond = tomoyo_get_condition(param);
109 if (!new_entry->cond)
110 return -EINVAL;
111 /*
112 * Domain transition preference is allowed for only
113 * "file execute" entries.
114 */
115 if (new_entry->cond->transit &&
116 !(new_entry->type == TOMOYO_TYPE_PATH_ACL &&
117 container_of(new_entry, struct tomoyo_path_acl, head)
118 ->perm == 1 << TOMOYO_TYPE_EXECUTE))
119 goto out;
120 }
121 if (mutex_lock_interruptible(&tomoyo_policy_lock))
122 goto out;
123 list_for_each_entry_rcu(entry, list, list,
124 srcu_read_lock_held(&tomoyo_ss)) {
125 if (entry->is_deleted == TOMOYO_GC_IN_PROGRESS)
126 continue;
127 if (!tomoyo_same_acl_head(entry, new_entry) ||
128 !check_duplicate(entry, new_entry))
129 continue;
130 if (merge_duplicate)
131 entry->is_deleted = merge_duplicate(entry, new_entry,
132 is_delete);
133 else
134 entry->is_deleted = is_delete;
135 error = 0;
136 break;
137 }
138 if (error && !is_delete) {
139 entry = tomoyo_commit_ok(new_entry, size);
140 if (entry) {
141 list_add_tail_rcu(&entry->list, list);
142 error = 0;
143 }
144 }
145 mutex_unlock(&tomoyo_policy_lock);
146 out:
147 tomoyo_put_condition(new_entry->cond);
148 return error;
149 }
150
151 /**
152 * tomoyo_check_acl - Do permission check.
153 *
154 * @r: Pointer to "struct tomoyo_request_info".
155 * @check_entry: Callback function to check type specific parameters.
156 *
157 * Returns 0 on success, negative value otherwise.
158 *
159 * Caller holds tomoyo_read_lock().
160 */
161 void tomoyo_check_acl(struct tomoyo_request_info *r,
162 bool (*check_entry)(struct tomoyo_request_info *,
163 const struct tomoyo_acl_info *))
164 {
165 const struct tomoyo_domain_info *domain = r->domain;
166 struct tomoyo_acl_info *ptr;
167 const struct list_head *list = &domain->acl_info_list;
168 u16 i = 0;
169
170 retry:
171 list_for_each_entry_rcu(ptr, list, list,
172 srcu_read_lock_held(&tomoyo_ss)) {
173 if (ptr->is_deleted || ptr->type != r->param_type)
174 continue;
175 if (!check_entry(r, ptr))
176 continue;
177 if (!tomoyo_condition(r, ptr->cond))
178 continue;
179 r->matched_acl = ptr;
180 r->granted = true;
181 return;
182 }
183 for (; i < TOMOYO_MAX_ACL_GROUPS; i++) {
184 if (!test_bit(i, domain->group))
185 continue;
186 list = &domain->ns->acl_group[i++];
187 goto retry;
188 }
189 r->granted = false;
190 }
191
192 /* The list for "struct tomoyo_domain_info". */
193 LIST_HEAD(tomoyo_domain_list);
194
195 /**
196 * tomoyo_last_word - Get last component of a domainname.
197 *
198 * @name: Domainname to check.
199 *
200 * Returns the last word of @domainname.
201 */
202 static const char *tomoyo_last_word(const char *name)
203 {
204 const char *cp = strrchr(name, ' ');
205
206 if (cp)
207 return cp + 1;
208 return name;
209 }
210
211 /**
212 * tomoyo_same_transition_control - Check for duplicated "struct tomoyo_transition_control" entry.
213 *
214 * @a: Pointer to "struct tomoyo_acl_head".
215 * @b: Pointer to "struct tomoyo_acl_head".
216 *
217 * Returns true if @a == @b, false otherwise.
218 */
219 static bool tomoyo_same_transition_control(const struct tomoyo_acl_head *a,
220 const struct tomoyo_acl_head *b)
221 {
222 const struct tomoyo_transition_control *p1 = container_of(a,
223 typeof(*p1),
224 head);
225 const struct tomoyo_transition_control *p2 = container_of(b,
226 typeof(*p2),
227 head);
228
229 return p1->type == p2->type && p1->is_last_name == p2->is_last_name
230 && p1->domainname == p2->domainname
231 && p1->program == p2->program;
232 }
233
234 /**
235 * tomoyo_write_transition_control - Write "struct tomoyo_transition_control" list.
236 *
237 * @param: Pointer to "struct tomoyo_acl_param".
238 * @type: Type of this entry.
239 *
240 * Returns 0 on success, negative value otherwise.
241 */
242 int tomoyo_write_transition_control(struct tomoyo_acl_param *param,
243 const u8 type)
244 {
245 struct tomoyo_transition_control e = { .type = type };
246 int error = param->is_delete ? -ENOENT : -ENOMEM;
247 char *program = param->data;
248 char *domainname = strstr(program, " from ");
249
250 if (domainname) {
251 *domainname = '\0';
252 domainname += 6;
253 } else if (type == TOMOYO_TRANSITION_CONTROL_NO_KEEP ||
254 type == TOMOYO_TRANSITION_CONTROL_KEEP) {
255 domainname = program;
256 program = NULL;
257 }
258 if (program && strcmp(program, "any")) {
259 if (!tomoyo_correct_path(program))
260 return -EINVAL;
261 e.program = tomoyo_get_name(program);
262 if (!e.program)
263 goto out;
264 }
265 if (domainname && strcmp(domainname, "any")) {
266 if (!tomoyo_correct_domain(domainname)) {
267 if (!tomoyo_correct_path(domainname))
268 goto out;
269 e.is_last_name = true;
270 }
271 e.domainname = tomoyo_get_name(domainname);
272 if (!e.domainname)
273 goto out;
274 }
275 param->list = ¶m->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
276 error = tomoyo_update_policy(&e.head, sizeof(e), param,
277 tomoyo_same_transition_control);
278 out:
279 tomoyo_put_name(e.domainname);
280 tomoyo_put_name(e.program);
281 return error;
282 }
283
284 /**
285 * tomoyo_scan_transition - Try to find specific domain transition type.
286 *
287 * @list: Pointer to "struct list_head".
288 * @domainname: The name of current domain.
289 * @program: The name of requested program.
290 * @last_name: The last component of @domainname.
291 * @type: One of values in "enum tomoyo_transition_type".
292 *
293 * Returns true if found one, false otherwise.
294 *
295 * Caller holds tomoyo_read_lock().
296 */
297 static inline bool tomoyo_scan_transition
298 (const struct list_head *list, const struct tomoyo_path_info *domainname,
299 const struct tomoyo_path_info *program, const char *last_name,
300 const enum tomoyo_transition_type type)
301 {
302 const struct tomoyo_transition_control *ptr;
303
304 list_for_each_entry_rcu(ptr, list, head.list,
305 srcu_read_lock_held(&tomoyo_ss)) {
306 if (ptr->head.is_deleted || ptr->type != type)
307 continue;
308 if (ptr->domainname) {
309 if (!ptr->is_last_name) {
310 if (ptr->domainname != domainname)
311 continue;
312 } else {
313 /*
314 * Use direct strcmp() since this is
315 * unlikely used.
316 */
317 if (strcmp(ptr->domainname->name, last_name))
318 continue;
319 }
320 }
321 if (ptr->program && tomoyo_pathcmp(ptr->program, program))
322 continue;
323 return true;
324 }
325 return false;
326 }
327
328 /**
329 * tomoyo_transition_type - Get domain transition type.
330 *
331 * @ns: Pointer to "struct tomoyo_policy_namespace".
332 * @domainname: The name of current domain.
333 * @program: The name of requested program.
334 *
335 * Returns TOMOYO_TRANSITION_CONTROL_TRANSIT if executing @program causes
336 * domain transition across namespaces, TOMOYO_TRANSITION_CONTROL_INITIALIZE if
337 * executing @program reinitializes domain transition within that namespace,
338 * TOMOYO_TRANSITION_CONTROL_KEEP if executing @program stays at @domainname ,
339 * others otherwise.
340 *
341 * Caller holds tomoyo_read_lock().
342 */
343 static enum tomoyo_transition_type tomoyo_transition_type
344 (const struct tomoyo_policy_namespace *ns,
345 const struct tomoyo_path_info *domainname,
346 const struct tomoyo_path_info *program)
347 {
348 const char *last_name = tomoyo_last_word(domainname->name);
349 enum tomoyo_transition_type type = TOMOYO_TRANSITION_CONTROL_NO_RESET;
350
351 while (type < TOMOYO_MAX_TRANSITION_TYPE) {
352 const struct list_head * const list =
353 &ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
354
355 if (!tomoyo_scan_transition(list, domainname, program,
356 last_name, type)) {
357 type++;
358 continue;
359 }
360 if (type != TOMOYO_TRANSITION_CONTROL_NO_RESET &&
361 type != TOMOYO_TRANSITION_CONTROL_NO_INITIALIZE)
362 break;
363 /*
364 * Do not check for reset_domain if no_reset_domain matched.
365 * Do not check for initialize_domain if no_initialize_domain
366 * matched.
367 */
368 type++;
369 type++;
370 }
371 return type;
372 }
373
374 /**
375 * tomoyo_same_aggregator - Check for duplicated "struct tomoyo_aggregator" entry.
376 *
377 * @a: Pointer to "struct tomoyo_acl_head".
378 * @b: Pointer to "struct tomoyo_acl_head".
379 *
380 * Returns true if @a == @b, false otherwise.
381 */
382 static bool tomoyo_same_aggregator(const struct tomoyo_acl_head *a,
383 const struct tomoyo_acl_head *b)
384 {
385 const struct tomoyo_aggregator *p1 = container_of(a, typeof(*p1),
386 head);
387 const struct tomoyo_aggregator *p2 = container_of(b, typeof(*p2),
388 head);
389
390 return p1->original_name == p2->original_name &&
391 p1->aggregated_name == p2->aggregated_name;
392 }
393
394 /**
395 * tomoyo_write_aggregator - Write "struct tomoyo_aggregator" list.
396 *
397 * @param: Pointer to "struct tomoyo_acl_param".
398 *
399 * Returns 0 on success, negative value otherwise.
400 *
401 * Caller holds tomoyo_read_lock().
402 */
403 int tomoyo_write_aggregator(struct tomoyo_acl_param *param)
404 {
405 struct tomoyo_aggregator e = { };
406 int error = param->is_delete ? -ENOENT : -ENOMEM;
407 const char *original_name = tomoyo_read_token(param);
408 const char *aggregated_name = tomoyo_read_token(param);
409
410 if (!tomoyo_correct_word(original_name) ||
411 !tomoyo_correct_path(aggregated_name))
412 return -EINVAL;
413 e.original_name = tomoyo_get_name(original_name);
414 e.aggregated_name = tomoyo_get_name(aggregated_name);
415 if (!e.original_name || !e.aggregated_name ||
416 e.aggregated_name->is_patterned) /* No patterns allowed. */
417 goto out;
418 param->list = ¶m->ns->policy_list[TOMOYO_ID_AGGREGATOR];
419 error = tomoyo_update_policy(&e.head, sizeof(e), param,
420 tomoyo_same_aggregator);
421 out:
422 tomoyo_put_name(e.original_name);
423 tomoyo_put_name(e.aggregated_name);
424 return error;
425 }
426
427 /**
428 * tomoyo_find_namespace - Find specified namespace.
429 *
430 * @name: Name of namespace to find.
431 * @len: Length of @name.
432 *
433 * Returns pointer to "struct tomoyo_policy_namespace" if found,
434 * NULL otherwise.
435 *
436 * Caller holds tomoyo_read_lock().
437 */
438 static struct tomoyo_policy_namespace *tomoyo_find_namespace
439 (const char *name, const unsigned int len)
440 {
441 struct tomoyo_policy_namespace *ns;
442
443 list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
444 if (strncmp(name, ns->name, len) ||
445 (name[len] && name[len] != ' '))
446 continue;
447 return ns;
448 }
449 return NULL;
450 }
451
452 /**
453 * tomoyo_assign_namespace - Create a new namespace.
454 *
455 * @domainname: Name of namespace to create.
456 *
457 * Returns pointer to "struct tomoyo_policy_namespace" on success,
458 * NULL otherwise.
459 *
460 * Caller holds tomoyo_read_lock().
461 */
462 struct tomoyo_policy_namespace *tomoyo_assign_namespace(const char *domainname)
463 {
464 struct tomoyo_policy_namespace *ptr;
465 struct tomoyo_policy_namespace *entry;
466 const char *cp = domainname;
467 unsigned int len = 0;
468
469 while (*cp && *cp++ != ' ')
470 len++;
471 ptr = tomoyo_find_namespace(domainname, len);
472 if (ptr)
473 return ptr;
474 if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(domainname))
475 return NULL;
476 entry = kzalloc(sizeof(*entry) + len + 1, GFP_NOFS | __GFP_NOWARN);
477 if (mutex_lock_interruptible(&tomoyo_policy_lock))
478 goto out;
479 ptr = tomoyo_find_namespace(domainname, len);
480 if (!ptr && tomoyo_memory_ok(entry)) {
481 char *name = (char *) (entry + 1);
482
483 ptr = entry;
484 memmove(name, domainname, len);
485 name[len] = '\0';
486 entry->name = name;
487 tomoyo_init_policy_namespace(entry);
488 entry = NULL;
489 }
490 mutex_unlock(&tomoyo_policy_lock);
491 out:
492 kfree(entry);
493 return ptr;
494 }
495
496 /**
497 * tomoyo_namespace_jump - Check for namespace jump.
498 *
499 * @domainname: Name of domain.
500 *
501 * Returns true if namespace differs, false otherwise.
502 */
503 static bool tomoyo_namespace_jump(const char *domainname)
504 {
505 const char *namespace = tomoyo_current_namespace()->name;
506 const int len = strlen(namespace);
507
508 return strncmp(domainname, namespace, len) ||
509 (domainname[len] && domainname[len] != ' ');
510 }
511
512 /**
513 * tomoyo_assign_domain - Create a domain or a namespace.
514 *
515 * @domainname: The name of domain.
516 * @transit: True if transit to domain found or created.
517 *
518 * Returns pointer to "struct tomoyo_domain_info" on success, NULL otherwise.
519 *
520 * Caller holds tomoyo_read_lock().
521 */
522 struct tomoyo_domain_info *tomoyo_assign_domain(const char *domainname,
523 const bool transit)
524 {
525 struct tomoyo_domain_info e = { };
526 struct tomoyo_domain_info *entry = tomoyo_find_domain(domainname);
527 bool created = false;
528
529 if (entry) {
530 if (transit) {
531 /*
532 * Since namespace is created at runtime, profiles may
533 * not be created by the moment the process transits to
534 * that domain. Do not perform domain transition if
535 * profile for that domain is not yet created.
536 */
537 if (tomoyo_policy_loaded &&
538 !entry->ns->profile_ptr[entry->profile])
539 return NULL;
540 }
541 return entry;
542 }
543 /* Requested domain does not exist. */
544 /* Don't create requested domain if domainname is invalid. */
545 if (strlen(domainname) >= TOMOYO_EXEC_TMPSIZE - 10 ||
546 !tomoyo_correct_domain(domainname))
547 return NULL;
548 /*
549 * Since definition of profiles and acl_groups may differ across
550 * namespaces, do not inherit "use_profile" and "use_group" settings
551 * by automatically creating requested domain upon domain transition.
552 */
553 if (transit && tomoyo_namespace_jump(domainname))
554 return NULL;
555 e.ns = tomoyo_assign_namespace(domainname);
556 if (!e.ns)
557 return NULL;
558 /*
559 * "use_profile" and "use_group" settings for automatically created
560 * domains are inherited from current domain. These are 0 for manually
561 * created domains.
562 */
563 if (transit) {
564 const struct tomoyo_domain_info *domain = tomoyo_domain();
565
566 e.profile = domain->profile;
567 memcpy(e.group, domain->group, sizeof(e.group));
568 }
569 e.domainname = tomoyo_get_name(domainname);
570 if (!e.domainname)
571 return NULL;
572 if (mutex_lock_interruptible(&tomoyo_policy_lock))
573 goto out;
574 entry = tomoyo_find_domain(domainname);
575 if (!entry) {
576 entry = tomoyo_commit_ok(&e, sizeof(e));
577 if (entry) {
578 INIT_LIST_HEAD(&entry->acl_info_list);
579 list_add_tail_rcu(&entry->list, &tomoyo_domain_list);
580 created = true;
581 }
582 }
583 mutex_unlock(&tomoyo_policy_lock);
584 out:
585 tomoyo_put_name(e.domainname);
586 if (entry && transit) {
587 if (created) {
588 struct tomoyo_request_info r;
589 int i;
590
591 tomoyo_init_request_info(&r, entry,
592 TOMOYO_MAC_FILE_EXECUTE);
593 r.granted = false;
594 tomoyo_write_log(&r, "use_profile %u\n",
595 entry->profile);
596 for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++)
597 if (test_bit(i, entry->group))
598 tomoyo_write_log(&r, "use_group %u\n",
599 i);
600 tomoyo_update_stat(TOMOYO_STAT_POLICY_UPDATES);
601 }
602 }
603 return entry;
604 }
605
606 /**
607 * tomoyo_environ - Check permission for environment variable names.
608 *
609 * @ee: Pointer to "struct tomoyo_execve".
610 *
611 * Returns 0 on success, negative value otherwise.
612 */
613 static int tomoyo_environ(struct tomoyo_execve *ee)
614 {
615 struct tomoyo_request_info *r = &ee->r;
616 struct linux_binprm *bprm = ee->bprm;
617 /* env_page.data is allocated by tomoyo_dump_page(). */
618 struct tomoyo_page_dump env_page = { };
619 char *arg_ptr; /* Size is TOMOYO_EXEC_TMPSIZE bytes */
620 int arg_len = 0;
621 unsigned long pos = bprm->p;
622 int offset = pos % PAGE_SIZE;
623 int argv_count = bprm->argc;
624 int envp_count = bprm->envc;
625 int error = -ENOMEM;
626
627 ee->r.type = TOMOYO_MAC_ENVIRON;
628 ee->r.profile = r->domain->profile;
629 ee->r.mode = tomoyo_get_mode(r->domain->ns, ee->r.profile,
630 TOMOYO_MAC_ENVIRON);
631 if (!r->mode || !envp_count)
632 return 0;
633 arg_ptr = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
634 if (!arg_ptr)
635 goto out;
636 while (error == -ENOMEM) {
637 if (!tomoyo_dump_page(bprm, pos, &env_page))
638 goto out;
639 pos += PAGE_SIZE - offset;
640 /* Read. */
641 while (argv_count && offset < PAGE_SIZE) {
642 if (!env_page.data[offset++])
643 argv_count--;
644 }
645 if (argv_count) {
646 offset = 0;
647 continue;
648 }
649 while (offset < PAGE_SIZE) {
650 const unsigned char c = env_page.data[offset++];
651
652 if (c && arg_len < TOMOYO_EXEC_TMPSIZE - 10) {
653 if (c == '=') {
654 arg_ptr[arg_len++] = '\0';
655 } else if (c == '\\') {
656 arg_ptr[arg_len++] = '\\';
657 arg_ptr[arg_len++] = '\\';
658 } else if (c > ' ' && c < 127) {
659 arg_ptr[arg_len++] = c;
660 } else {
661 arg_ptr[arg_len++] = '\\';
662 arg_ptr[arg_len++] = (c >> 6) + '';
663 arg_ptr[arg_len++]
664 = ((c >> 3) & 7) + '';
665 arg_ptr[arg_len++] = (c & 7) + '';
666 }
667 } else {
668 arg_ptr[arg_len] = '\0';
669 }
670 if (c)
671 continue;
672 if (tomoyo_env_perm(r, arg_ptr)) {
673 error = -EPERM;
674 break;
675 }
676 if (!--envp_count) {
677 error = 0;
678 break;
679 }
680 arg_len = 0;
681 }
682 offset = 0;
683 }
684 out:
685 if (r->mode != TOMOYO_CONFIG_ENFORCING)
686 error = 0;
687 kfree(env_page.data);
688 kfree(arg_ptr);
689 return error;
690 }
691
692 /**
693 * tomoyo_find_next_domain - Find a domain.
694 *
695 * @bprm: Pointer to "struct linux_binprm".
696 *
697 * Returns 0 on success, negative value otherwise.
698 *
699 * Caller holds tomoyo_read_lock().
700 */
701 int tomoyo_find_next_domain(struct linux_binprm *bprm)
702 {
703 struct tomoyo_domain_info *old_domain = tomoyo_domain();
704 struct tomoyo_domain_info *domain = NULL;
705 const char *original_name = bprm->filename;
706 int retval = -ENOMEM;
707 bool reject_on_transition_failure = false;
708 const struct tomoyo_path_info *candidate;
709 struct tomoyo_path_info exename;
710 struct tomoyo_execve *ee = kzalloc(sizeof(*ee), GFP_NOFS);
711
712 if (!ee)
713 return -ENOMEM;
714 ee->tmp = kzalloc(TOMOYO_EXEC_TMPSIZE, GFP_NOFS);
715 if (!ee->tmp) {
716 kfree(ee);
717 return -ENOMEM;
718 }
719 /* ee->dump->data is allocated by tomoyo_dump_page(). */
720 tomoyo_init_request_info(&ee->r, NULL, TOMOYO_MAC_FILE_EXECUTE);
721 ee->r.ee = ee;
722 ee->bprm = bprm;
723 ee->r.obj = &ee->obj;
724 ee->obj.path1 = bprm->file->f_path;
725 /* Get symlink's pathname of program. */
726 exename.name = tomoyo_realpath_nofollow(original_name);
727 if (!exename.name) {
728 /* Fallback to realpath if symlink's pathname does not exist. */
729 exename.name = tomoyo_realpath_from_path(&bprm->file->f_path);
730 if (!exename.name)
731 goto out;
732 }
733 tomoyo_fill_path_info(&exename);
734 retry:
735 /* Check 'aggregator' directive. */
736 {
737 struct tomoyo_aggregator *ptr;
738 struct list_head *list =
739 &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
740
741 /* Check 'aggregator' directive. */
742 candidate = &exename;
743 list_for_each_entry_rcu(ptr, list, head.list,
744 srcu_read_lock_held(&tomoyo_ss)) {
745 if (ptr->head.is_deleted ||
746 !tomoyo_path_matches_pattern(&exename,
747 ptr->original_name))
748 continue;
749 candidate = ptr->aggregated_name;
750 break;
751 }
752 }
753
754 /* Check execute permission. */
755 retval = tomoyo_execute_permission(&ee->r, candidate);
756 if (retval == TOMOYO_RETRY_REQUEST)
757 goto retry;
758 if (retval < 0)
759 goto out;
760 /*
761 * To be able to specify domainnames with wildcards, use the
762 * pathname specified in the policy (which may contain
763 * wildcard) rather than the pathname passed to execve()
764 * (which never contains wildcard).
765 */
766 if (ee->r.param.path.matched_path)
767 candidate = ee->r.param.path.matched_path;
768
769 /*
770 * Check for domain transition preference if "file execute" matched.
771 * If preference is given, make execve() fail if domain transition
772 * has failed, for domain transition preference should be used with
773 * destination domain defined.
774 */
775 if (ee->transition) {
776 const char *domainname = ee->transition->name;
777
778 reject_on_transition_failure = true;
779 if (!strcmp(domainname, "keep"))
780 goto force_keep_domain;
781 if (!strcmp(domainname, "child"))
782 goto force_child_domain;
783 if (!strcmp(domainname, "reset"))
784 goto force_reset_domain;
785 if (!strcmp(domainname, "initialize"))
786 goto force_initialize_domain;
787 if (!strcmp(domainname, "parent")) {
788 char *cp;
789
790 strscpy(ee->tmp, old_domain->domainname->name, TOMOYO_EXEC_TMPSIZE);
791 cp = strrchr(ee->tmp, ' ');
792 if (cp)
793 *cp = '\0';
794 } else if (*domainname == '<')
795 strscpy(ee->tmp, domainname, TOMOYO_EXEC_TMPSIZE);
796 else
797 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
798 old_domain->domainname->name, domainname);
799 goto force_jump_domain;
800 }
801 /*
802 * No domain transition preference specified.
803 * Calculate domain to transit to.
804 */
805 switch (tomoyo_transition_type(old_domain->ns, old_domain->domainname,
806 candidate)) {
807 case TOMOYO_TRANSITION_CONTROL_RESET:
808 force_reset_domain:
809 /* Transit to the root of specified namespace. */
810 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "<%s>",
811 candidate->name);
812 /*
813 * Make execve() fail if domain transition across namespaces
814 * has failed.
815 */
816 reject_on_transition_failure = true;
817 break;
818 case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
819 force_initialize_domain:
820 /* Transit to the child of current namespace's root. */
821 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
822 old_domain->ns->name, candidate->name);
823 break;
824 case TOMOYO_TRANSITION_CONTROL_KEEP:
825 force_keep_domain:
826 /* Keep current domain. */
827 domain = old_domain;
828 break;
829 default:
830 if (old_domain == &tomoyo_kernel_domain &&
831 !tomoyo_policy_loaded) {
832 /*
833 * Needn't to transit from kernel domain before
834 * starting /sbin/init. But transit from kernel domain
835 * if executing initializers because they might start
836 * before /sbin/init.
837 */
838 domain = old_domain;
839 break;
840 }
841 force_child_domain:
842 /* Normal domain transition. */
843 snprintf(ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, "%s %s",
844 old_domain->domainname->name, candidate->name);
845 break;
846 }
847 force_jump_domain:
848 if (!domain)
849 domain = tomoyo_assign_domain(ee->tmp, true);
850 if (domain)
851 retval = 0;
852 else if (reject_on_transition_failure) {
853 pr_warn("ERROR: Domain '%s' not ready.\n", ee->tmp);
854 retval = -ENOMEM;
855 } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
856 retval = -ENOMEM;
857 else {
858 retval = 0;
859 if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
860 old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
861 ee->r.granted = false;
862 tomoyo_write_log(&ee->r, "%s", tomoyo_dif
863 [TOMOYO_DIF_TRANSITION_FAILED]);
864 pr_warn("ERROR: Domain '%s' not defined.\n", ee->tmp);
865 }
866 }
867 out:
868 if (!domain)
869 domain = old_domain;
870 /* Update reference count on "struct tomoyo_domain_info". */
871 {
872 struct tomoyo_task *s = tomoyo_task(current);
873
874 s->old_domain_info = s->domain_info;
875 s->domain_info = domain;
876 atomic_inc(&domain->users);
877 }
878 kfree(exename.name);
879 if (!retval) {
880 ee->r.domain = domain;
881 retval = tomoyo_environ(ee);
882 }
883 kfree(ee->tmp);
884 kfree(ee->dump.data);
885 kfree(ee);
886 return retval;
887 }
888
889 /**
890 * tomoyo_dump_page - Dump a page to buffer.
891 *
892 * @bprm: Pointer to "struct linux_binprm".
893 * @pos: Location to dump.
894 * @dump: Pointer to "struct tomoyo_page_dump".
895 *
896 * Returns true on success, false otherwise.
897 */
898 bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
899 struct tomoyo_page_dump *dump)
900 {
901 struct page *page;
902 #ifdef CONFIG_MMU
903 int ret;
904 #endif
905
906 /* dump->data is released by tomoyo_find_next_domain(). */
907 if (!dump->data) {
908 dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
909 if (!dump->data)
910 return false;
911 }
912 /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
913 #ifdef CONFIG_MMU
914 /*
915 * This is called at execve() time in order to dig around
916 * in the argv/environment of the new proceess
917 * (represented by bprm).
918 */
919 mmap_read_lock(bprm->mm);
920 ret = get_user_pages_remote(bprm->mm, pos, 1,
921 FOLL_FORCE, &page, NULL);
922 mmap_read_unlock(bprm->mm);
923 if (ret <= 0)
924 return false;
925 #else
926 page = bprm->page[pos / PAGE_SIZE];
927 #endif
928 if (page != dump->page) {
929 const unsigned int offset = pos % PAGE_SIZE;
930 /*
931 * Maybe kmap()/kunmap() should be used here.
932 * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
933 * So do I.
934 */
935 char *kaddr = kmap_atomic(page);
936
937 dump->page = page;
938 memcpy(dump->data + offset, kaddr + offset,
939 PAGE_SIZE - offset);
940 kunmap_atomic(kaddr);
941 }
942 /* Same with put_arg_page(page) in fs/exec.c */
943 #ifdef CONFIG_MMU
944 put_page(page);
945 #endif
946 return true;
947 }
948
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.