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. */
17struct 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 */
31int 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(data: new_entry, size);
56 if (entry) {
57 list_add_tail_rcu(new: &entry->list, head: list);
58 error = 0;
59 }
60 }
61 mutex_unlock(lock: &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 */
73static 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 */
92int 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(a: entry, b: 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(data: new_entry, size);
140 if (entry) {
141 list_add_tail_rcu(new: &entry->list, head: list);
142 error = 0;
143 }
144 }
145 mutex_unlock(lock: &tomoyo_policy_lock);
146out:
147 tomoyo_put_condition(cond: 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 */
161void 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
170retry:
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, cond: 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". */
193LIST_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 */
202static 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 */
219static 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 */
242int 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(filename: program))
260 return -EINVAL;
261 e.program = tomoyo_get_name(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(filename: domainname))
268 goto out;
269 e.is_last_name = true;
270 }
271 e.domainname = tomoyo_get_name(name: domainname);
272 if (!e.domainname)
273 goto out;
274 }
275 param->list = &param->ns->policy_list[TOMOYO_ID_TRANSITION_CONTROL];
276 error = tomoyo_update_policy(new_entry: &e.head, size: sizeof(e), param,
277 check_duplicate: tomoyo_same_transition_control);
278out:
279 tomoyo_put_name(name: e.domainname);
280 tomoyo_put_name(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 */
297static 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(a: ptr->program, b: 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 */
343static 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(name: 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 */
382static 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 */
403int 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(string: original_name) ||
411 !tomoyo_correct_path(filename: aggregated_name))
412 return -EINVAL;
413 e.original_name = tomoyo_get_name(name: original_name);
414 e.aggregated_name = tomoyo_get_name(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 = &param->ns->policy_list[TOMOYO_ID_AGGREGATOR];
419 error = tomoyo_update_policy(new_entry: &e.head, size: sizeof(e), param,
420 check_duplicate: tomoyo_same_aggregator);
421out:
422 tomoyo_put_name(name: e.original_name);
423 tomoyo_put_name(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 */
438static 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 */
462struct 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(name: domainname, len);
472 if (ptr)
473 return ptr;
474 if (len >= TOMOYO_EXEC_TMPSIZE - 10 || !tomoyo_domain_def(buffer: domainname))
475 return NULL;
476 entry = kzalloc(size: sizeof(*entry) + len + 1, GFP_NOFS | __GFP_NOWARN);
477 if (mutex_lock_interruptible(&tomoyo_policy_lock))
478 goto out;
479 ptr = tomoyo_find_namespace(name: domainname, len);
480 if (!ptr && tomoyo_memory_ok(ptr: 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(ns: entry);
488 entry = NULL;
489 }
490 mutex_unlock(lock: &tomoyo_policy_lock);
491out:
492 kfree(objp: 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 */
503static 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 */
522struct 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(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(data: &e, size: sizeof(e));
577 if (entry) {
578 INIT_LIST_HEAD(list: &entry->acl_info_list);
579 list_add_tail_rcu(new: &entry->list, head: &tomoyo_domain_list);
580 created = true;
581 }
582 }
583 mutex_unlock(lock: &tomoyo_policy_lock);
584out:
585 tomoyo_put_name(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: &r, domain: entry,
592 index: TOMOYO_MAC_FILE_EXECUTE);
593 r.granted = false;
594 tomoyo_write_log(r: &r, fmt: "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: &r, fmt: "use_group %u\n",
599 i);
600 tomoyo_update_stat(index: 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 */
613static 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(ns: r->domain->ns, profile: ee->r.profile,
630 index: 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, dump: &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) + '0';
663 arg_ptr[arg_len++]
664 = ((c >> 3) & 7) + '0';
665 arg_ptr[arg_len++] = (c & 7) + '0';
666 }
667 } else {
668 arg_ptr[arg_len] = '\0';
669 }
670 if (c)
671 continue;
672 if (tomoyo_env_perm(r, env: 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 }
684out:
685 if (r->mode != TOMOYO_CONFIG_ENFORCING)
686 error = 0;
687 kfree(objp: env_page.data);
688 kfree(objp: 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 */
701int 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(size: 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(objp: ee);
717 return -ENOMEM;
718 }
719 /* ee->dump->data is allocated by tomoyo_dump_page(). */
720 tomoyo_init_request_info(r: &ee->r, NULL, index: 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 retval = -ENOENT;
727 exename.name = tomoyo_realpath_nofollow(pathname: original_name);
728 if (!exename.name)
729 goto out;
730 tomoyo_fill_path_info(ptr: &exename);
731retry:
732 /* Check 'aggregator' directive. */
733 {
734 struct tomoyo_aggregator *ptr;
735 struct list_head *list =
736 &old_domain->ns->policy_list[TOMOYO_ID_AGGREGATOR];
737
738 /* Check 'aggregator' directive. */
739 candidate = &exename;
740 list_for_each_entry_rcu(ptr, list, head.list,
741 srcu_read_lock_held(&tomoyo_ss)) {
742 if (ptr->head.is_deleted ||
743 !tomoyo_path_matches_pattern(filename: &exename,
744 pattern: ptr->original_name))
745 continue;
746 candidate = ptr->aggregated_name;
747 break;
748 }
749 }
750
751 /* Check execute permission. */
752 retval = tomoyo_execute_permission(r: &ee->r, filename: candidate);
753 if (retval == TOMOYO_RETRY_REQUEST)
754 goto retry;
755 if (retval < 0)
756 goto out;
757 /*
758 * To be able to specify domainnames with wildcards, use the
759 * pathname specified in the policy (which may contain
760 * wildcard) rather than the pathname passed to execve()
761 * (which never contains wildcard).
762 */
763 if (ee->r.param.path.matched_path)
764 candidate = ee->r.param.path.matched_path;
765
766 /*
767 * Check for domain transition preference if "file execute" matched.
768 * If preference is given, make execve() fail if domain transition
769 * has failed, for domain transition preference should be used with
770 * destination domain defined.
771 */
772 if (ee->transition) {
773 const char *domainname = ee->transition->name;
774
775 reject_on_transition_failure = true;
776 if (!strcmp(domainname, "keep"))
777 goto force_keep_domain;
778 if (!strcmp(domainname, "child"))
779 goto force_child_domain;
780 if (!strcmp(domainname, "reset"))
781 goto force_reset_domain;
782 if (!strcmp(domainname, "initialize"))
783 goto force_initialize_domain;
784 if (!strcmp(domainname, "parent")) {
785 char *cp;
786
787 strscpy(p: ee->tmp, q: old_domain->domainname->name, TOMOYO_EXEC_TMPSIZE);
788 cp = strrchr(ee->tmp, ' ');
789 if (cp)
790 *cp = '\0';
791 } else if (*domainname == '<')
792 strscpy(p: ee->tmp, q: domainname, TOMOYO_EXEC_TMPSIZE);
793 else
794 snprintf(buf: ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, fmt: "%s %s",
795 old_domain->domainname->name, domainname);
796 goto force_jump_domain;
797 }
798 /*
799 * No domain transition preference specified.
800 * Calculate domain to transit to.
801 */
802 switch (tomoyo_transition_type(ns: old_domain->ns, domainname: old_domain->domainname,
803 program: candidate)) {
804 case TOMOYO_TRANSITION_CONTROL_RESET:
805force_reset_domain:
806 /* Transit to the root of specified namespace. */
807 snprintf(buf: ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, fmt: "<%s>",
808 candidate->name);
809 /*
810 * Make execve() fail if domain transition across namespaces
811 * has failed.
812 */
813 reject_on_transition_failure = true;
814 break;
815 case TOMOYO_TRANSITION_CONTROL_INITIALIZE:
816force_initialize_domain:
817 /* Transit to the child of current namespace's root. */
818 snprintf(buf: ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, fmt: "%s %s",
819 old_domain->ns->name, candidate->name);
820 break;
821 case TOMOYO_TRANSITION_CONTROL_KEEP:
822force_keep_domain:
823 /* Keep current domain. */
824 domain = old_domain;
825 break;
826 default:
827 if (old_domain == &tomoyo_kernel_domain &&
828 !tomoyo_policy_loaded) {
829 /*
830 * Needn't to transit from kernel domain before
831 * starting /sbin/init. But transit from kernel domain
832 * if executing initializers because they might start
833 * before /sbin/init.
834 */
835 domain = old_domain;
836 break;
837 }
838force_child_domain:
839 /* Normal domain transition. */
840 snprintf(buf: ee->tmp, TOMOYO_EXEC_TMPSIZE - 1, fmt: "%s %s",
841 old_domain->domainname->name, candidate->name);
842 break;
843 }
844force_jump_domain:
845 if (!domain)
846 domain = tomoyo_assign_domain(domainname: ee->tmp, transit: true);
847 if (domain)
848 retval = 0;
849 else if (reject_on_transition_failure) {
850 pr_warn("ERROR: Domain '%s' not ready.\n", ee->tmp);
851 retval = -ENOMEM;
852 } else if (ee->r.mode == TOMOYO_CONFIG_ENFORCING)
853 retval = -ENOMEM;
854 else {
855 retval = 0;
856 if (!old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED]) {
857 old_domain->flags[TOMOYO_DIF_TRANSITION_FAILED] = true;
858 ee->r.granted = false;
859 tomoyo_write_log(r: &ee->r, fmt: "%s", tomoyo_dif
860 [TOMOYO_DIF_TRANSITION_FAILED]);
861 pr_warn("ERROR: Domain '%s' not defined.\n", ee->tmp);
862 }
863 }
864 out:
865 if (!domain)
866 domain = old_domain;
867 /* Update reference count on "struct tomoyo_domain_info". */
868 {
869 struct tomoyo_task *s = tomoyo_task(current);
870
871 s->old_domain_info = s->domain_info;
872 s->domain_info = domain;
873 atomic_inc(v: &domain->users);
874 }
875 kfree(objp: exename.name);
876 if (!retval) {
877 ee->r.domain = domain;
878 retval = tomoyo_environ(ee);
879 }
880 kfree(objp: ee->tmp);
881 kfree(objp: ee->dump.data);
882 kfree(objp: ee);
883 return retval;
884}
885
886/**
887 * tomoyo_dump_page - Dump a page to buffer.
888 *
889 * @bprm: Pointer to "struct linux_binprm".
890 * @pos: Location to dump.
891 * @dump: Pointer to "struct tomoyo_page_dump".
892 *
893 * Returns true on success, false otherwise.
894 */
895bool tomoyo_dump_page(struct linux_binprm *bprm, unsigned long pos,
896 struct tomoyo_page_dump *dump)
897{
898 struct page *page;
899#ifdef CONFIG_MMU
900 int ret;
901#endif
902
903 /* dump->data is released by tomoyo_find_next_domain(). */
904 if (!dump->data) {
905 dump->data = kzalloc(PAGE_SIZE, GFP_NOFS);
906 if (!dump->data)
907 return false;
908 }
909 /* Same with get_arg_page(bprm, pos, 0) in fs/exec.c */
910#ifdef CONFIG_MMU
911 /*
912 * This is called at execve() time in order to dig around
913 * in the argv/environment of the new proceess
914 * (represented by bprm).
915 */
916 mmap_read_lock(mm: bprm->mm);
917 ret = get_user_pages_remote(mm: bprm->mm, start: pos, nr_pages: 1,
918 gup_flags: FOLL_FORCE, pages: &page, NULL);
919 mmap_read_unlock(mm: bprm->mm);
920 if (ret <= 0)
921 return false;
922#else
923 page = bprm->page[pos / PAGE_SIZE];
924#endif
925 if (page != dump->page) {
926 const unsigned int offset = pos % PAGE_SIZE;
927 /*
928 * Maybe kmap()/kunmap() should be used here.
929 * But remove_arg_zero() uses kmap_atomic()/kunmap_atomic().
930 * So do I.
931 */
932 char *kaddr = kmap_atomic(page);
933
934 dump->page = page;
935 memcpy(dump->data + offset, kaddr + offset,
936 PAGE_SIZE - offset);
937 kunmap_atomic(kaddr);
938 }
939 /* Same with put_arg_page(page) in fs/exec.c */
940#ifdef CONFIG_MMU
941 put_page(page);
942#endif
943 return true;
944}
945

source code of linux/security/tomoyo/domain.c