4 * Copyright (C) 2005-2011 NTT DATA CORPORATION
8 #include <linux/kthread.h>
9 #include <linux/slab.h>
11 /* The list for "struct tomoyo_io_buffer". */
12 static LIST_HEAD(tomoyo_io_buffer_list);
13 /* Lock for protecting tomoyo_io_buffer_list. */
14 static DEFINE_SPINLOCK(tomoyo_io_buffer_list_lock);
17 * tomoyo_struct_used_by_io_buffer - Check whether the list element is used by /sys/kernel/security/tomoyo/ users or not.
19 * @element: Pointer to "struct list_head".
21 * Returns true if @element is used by /sys/kernel/security/tomoyo/ users,
24 static bool tomoyo_struct_used_by_io_buffer(const struct list_head *element)
26 struct tomoyo_io_buffer *head;
29 spin_lock(&tomoyo_io_buffer_list_lock);
30 list_for_each_entry(head, &tomoyo_io_buffer_list, list) {
32 spin_unlock(&tomoyo_io_buffer_list_lock);
33 mutex_lock(&head->io_sem);
34 if (head->r.domain == element || head->r.group == element ||
35 head->r.acl == element || &head->w.domain->list == element)
37 mutex_unlock(&head->io_sem);
38 spin_lock(&tomoyo_io_buffer_list_lock);
43 spin_unlock(&tomoyo_io_buffer_list_lock);
48 * tomoyo_name_used_by_io_buffer - Check whether the string is used by /sys/kernel/security/tomoyo/ users or not.
50 * @string: String to check.
52 * Returns true if @string is used by /sys/kernel/security/tomoyo/ users,
55 static bool tomoyo_name_used_by_io_buffer(const char *string)
57 struct tomoyo_io_buffer *head;
58 const size_t size = strlen(string) + 1;
61 spin_lock(&tomoyo_io_buffer_list_lock);
62 list_for_each_entry(head, &tomoyo_io_buffer_list, list) {
65 spin_unlock(&tomoyo_io_buffer_list_lock);
66 mutex_lock(&head->io_sem);
67 for (i = 0; i < TOMOYO_MAX_IO_READ_QUEUE; i++) {
68 const char *w = head->r.w[i];
69 if (w < string || w > string + size)
74 mutex_unlock(&head->io_sem);
75 spin_lock(&tomoyo_io_buffer_list_lock);
80 spin_unlock(&tomoyo_io_buffer_list_lock);
85 * tomoyo_del_transition_control - Delete members in "struct tomoyo_transition_control".
87 * @element: Pointer to "struct list_head".
91 static inline void tomoyo_del_transition_control(struct list_head *element)
93 struct tomoyo_transition_control *ptr =
94 container_of(element, typeof(*ptr), head.list);
95 tomoyo_put_name(ptr->domainname);
96 tomoyo_put_name(ptr->program);
100 * tomoyo_del_aggregator - Delete members in "struct tomoyo_aggregator".
102 * @element: Pointer to "struct list_head".
106 static inline void tomoyo_del_aggregator(struct list_head *element)
108 struct tomoyo_aggregator *ptr =
109 container_of(element, typeof(*ptr), head.list);
110 tomoyo_put_name(ptr->original_name);
111 tomoyo_put_name(ptr->aggregated_name);
115 * tomoyo_del_manager - Delete members in "struct tomoyo_manager".
117 * @element: Pointer to "struct list_head".
121 static inline void tomoyo_del_manager(struct list_head *element)
123 struct tomoyo_manager *ptr =
124 container_of(element, typeof(*ptr), head.list);
125 tomoyo_put_name(ptr->manager);
129 * tomoyo_del_acl - Delete members in "struct tomoyo_acl_info".
131 * @element: Pointer to "struct list_head".
135 static void tomoyo_del_acl(struct list_head *element)
137 struct tomoyo_acl_info *acl =
138 container_of(element, typeof(*acl), list);
139 tomoyo_put_condition(acl->cond);
141 case TOMOYO_TYPE_PATH_ACL:
143 struct tomoyo_path_acl *entry
144 = container_of(acl, typeof(*entry), head);
145 tomoyo_put_name_union(&entry->name);
148 case TOMOYO_TYPE_PATH2_ACL:
150 struct tomoyo_path2_acl *entry
151 = container_of(acl, typeof(*entry), head);
152 tomoyo_put_name_union(&entry->name1);
153 tomoyo_put_name_union(&entry->name2);
156 case TOMOYO_TYPE_PATH_NUMBER_ACL:
158 struct tomoyo_path_number_acl *entry
159 = container_of(acl, typeof(*entry), head);
160 tomoyo_put_name_union(&entry->name);
161 tomoyo_put_number_union(&entry->number);
164 case TOMOYO_TYPE_MKDEV_ACL:
166 struct tomoyo_mkdev_acl *entry
167 = container_of(acl, typeof(*entry), head);
168 tomoyo_put_name_union(&entry->name);
169 tomoyo_put_number_union(&entry->mode);
170 tomoyo_put_number_union(&entry->major);
171 tomoyo_put_number_union(&entry->minor);
174 case TOMOYO_TYPE_MOUNT_ACL:
176 struct tomoyo_mount_acl *entry
177 = container_of(acl, typeof(*entry), head);
178 tomoyo_put_name_union(&entry->dev_name);
179 tomoyo_put_name_union(&entry->dir_name);
180 tomoyo_put_name_union(&entry->fs_type);
181 tomoyo_put_number_union(&entry->flags);
184 case TOMOYO_TYPE_ENV_ACL:
186 struct tomoyo_env_acl *entry =
187 container_of(acl, typeof(*entry), head);
189 tomoyo_put_name(entry->env);
192 case TOMOYO_TYPE_INET_ACL:
194 struct tomoyo_inet_acl *entry =
195 container_of(acl, typeof(*entry), head);
197 tomoyo_put_group(entry->address.group);
198 tomoyo_put_number_union(&entry->port);
201 case TOMOYO_TYPE_UNIX_ACL:
203 struct tomoyo_unix_acl *entry =
204 container_of(acl, typeof(*entry), head);
206 tomoyo_put_name_union(&entry->name);
213 * tomoyo_del_domain - Delete members in "struct tomoyo_domain_info".
215 * @element: Pointer to "struct list_head".
219 static inline void tomoyo_del_domain(struct list_head *element)
221 struct tomoyo_domain_info *domain =
222 container_of(element, typeof(*domain), list);
223 struct tomoyo_acl_info *acl;
224 struct tomoyo_acl_info *tmp;
226 * Since this domain is referenced from neither
227 * "struct tomoyo_io_buffer" nor "struct cred"->security, we can delete
228 * elements without checking for is_deleted flag.
230 list_for_each_entry_safe(acl, tmp, &domain->acl_info_list, list) {
231 tomoyo_del_acl(&acl->list);
232 tomoyo_memory_free(acl);
234 tomoyo_put_name(domain->domainname);
238 * tomoyo_del_condition - Delete members in "struct tomoyo_condition".
240 * @element: Pointer to "struct list_head".
244 void tomoyo_del_condition(struct list_head *element)
246 struct tomoyo_condition *cond = container_of(element, typeof(*cond),
248 const u16 condc = cond->condc;
249 const u16 numbers_count = cond->numbers_count;
250 const u16 names_count = cond->names_count;
251 const u16 argc = cond->argc;
252 const u16 envc = cond->envc;
254 const struct tomoyo_condition_element *condp
255 = (const struct tomoyo_condition_element *) (cond + 1);
256 struct tomoyo_number_union *numbers_p
257 = (struct tomoyo_number_union *) (condp + condc);
258 struct tomoyo_name_union *names_p
259 = (struct tomoyo_name_union *) (numbers_p + numbers_count);
260 const struct tomoyo_argv *argv
261 = (const struct tomoyo_argv *) (names_p + names_count);
262 const struct tomoyo_envp *envp
263 = (const struct tomoyo_envp *) (argv + argc);
264 for (i = 0; i < numbers_count; i++)
265 tomoyo_put_number_union(numbers_p++);
266 for (i = 0; i < names_count; i++)
267 tomoyo_put_name_union(names_p++);
268 for (i = 0; i < argc; argv++, i++)
269 tomoyo_put_name(argv->value);
270 for (i = 0; i < envc; envp++, i++) {
271 tomoyo_put_name(envp->name);
272 tomoyo_put_name(envp->value);
277 * tomoyo_del_name - Delete members in "struct tomoyo_name".
279 * @element: Pointer to "struct list_head".
283 static inline void tomoyo_del_name(struct list_head *element)
289 * tomoyo_del_path_group - Delete members in "struct tomoyo_path_group".
291 * @element: Pointer to "struct list_head".
295 static inline void tomoyo_del_path_group(struct list_head *element)
297 struct tomoyo_path_group *member =
298 container_of(element, typeof(*member), head.list);
299 tomoyo_put_name(member->member_name);
303 * tomoyo_del_group - Delete "struct tomoyo_group".
305 * @element: Pointer to "struct list_head".
309 static inline void tomoyo_del_group(struct list_head *element)
311 struct tomoyo_group *group =
312 container_of(element, typeof(*group), head.list);
313 tomoyo_put_name(group->group_name);
317 * tomoyo_del_address_group - Delete members in "struct tomoyo_address_group".
319 * @element: Pointer to "struct list_head".
323 static inline void tomoyo_del_address_group(struct list_head *element)
329 * tomoyo_del_number_group - Delete members in "struct tomoyo_number_group".
331 * @element: Pointer to "struct list_head".
335 static inline void tomoyo_del_number_group(struct list_head *element)
341 * tomoyo_try_to_gc - Try to kfree() an entry.
343 * @type: One of values in "enum tomoyo_policy_id".
344 * @element: Pointer to "struct list_head".
348 * Caller holds tomoyo_policy_lock mutex.
350 static void tomoyo_try_to_gc(const enum tomoyo_policy_id type,
351 struct list_head *element)
354 * __list_del_entry() guarantees that the list element became no longer
355 * reachable from the list which the element was originally on (e.g.
356 * tomoyo_domain_list). Also, synchronize_srcu() guarantees that the
357 * list element became no longer referenced by syscall users.
359 __list_del_entry(element);
360 mutex_unlock(&tomoyo_policy_lock);
361 synchronize_srcu(&tomoyo_ss);
363 * However, there are two users which may still be using the list
364 * element. We need to defer until both users forget this element.
366 * Don't kfree() until "struct tomoyo_io_buffer"->r.{domain,group,acl}
367 * and "struct tomoyo_io_buffer"->w.domain forget this element.
369 if (tomoyo_struct_used_by_io_buffer(element))
372 case TOMOYO_ID_TRANSITION_CONTROL:
373 tomoyo_del_transition_control(element);
375 case TOMOYO_ID_MANAGER:
376 tomoyo_del_manager(element);
378 case TOMOYO_ID_AGGREGATOR:
379 tomoyo_del_aggregator(element);
381 case TOMOYO_ID_GROUP:
382 tomoyo_del_group(element);
384 case TOMOYO_ID_PATH_GROUP:
385 tomoyo_del_path_group(element);
387 case TOMOYO_ID_ADDRESS_GROUP:
388 tomoyo_del_address_group(element);
390 case TOMOYO_ID_NUMBER_GROUP:
391 tomoyo_del_number_group(element);
393 case TOMOYO_ID_CONDITION:
394 tomoyo_del_condition(element);
398 * Don't kfree() until all "struct tomoyo_io_buffer"->r.w[]
399 * forget this element.
401 if (tomoyo_name_used_by_io_buffer
402 (container_of(element, typeof(struct tomoyo_name),
403 head.list)->entry.name))
405 tomoyo_del_name(element);
408 tomoyo_del_acl(element);
410 case TOMOYO_ID_DOMAIN:
412 * Don't kfree() until all "struct cred"->security forget this
415 if (atomic_read(&container_of
416 (element, typeof(struct tomoyo_domain_info),
419 tomoyo_del_domain(element);
421 case TOMOYO_MAX_POLICY:
424 mutex_lock(&tomoyo_policy_lock);
425 tomoyo_memory_free(element);
429 * We can safely reinject this element here bacause
430 * (1) Appending list elements and removing list elements are protected
431 * by tomoyo_policy_lock mutex.
432 * (2) Only this function removes list elements and this function is
433 * exclusively executed by tomoyo_gc_mutex mutex.
436 mutex_lock(&tomoyo_policy_lock);
437 list_add_rcu(element, element->prev);
441 * tomoyo_collect_member - Delete elements with "struct tomoyo_acl_head".
443 * @id: One of values in "enum tomoyo_policy_id".
444 * @member_list: Pointer to "struct list_head".
448 static void tomoyo_collect_member(const enum tomoyo_policy_id id,
449 struct list_head *member_list)
451 struct tomoyo_acl_head *member;
452 struct tomoyo_acl_head *tmp;
453 list_for_each_entry_safe(member, tmp, member_list, list) {
454 if (!member->is_deleted)
456 member->is_deleted = TOMOYO_GC_IN_PROGRESS;
457 tomoyo_try_to_gc(id, &member->list);
462 * tomoyo_collect_acl - Delete elements in "struct tomoyo_domain_info".
464 * @list: Pointer to "struct list_head".
468 static void tomoyo_collect_acl(struct list_head *list)
470 struct tomoyo_acl_info *acl;
471 struct tomoyo_acl_info *tmp;
472 list_for_each_entry_safe(acl, tmp, list, list) {
473 if (!acl->is_deleted)
475 acl->is_deleted = TOMOYO_GC_IN_PROGRESS;
476 tomoyo_try_to_gc(TOMOYO_ID_ACL, &acl->list);
481 * tomoyo_collect_entry - Try to kfree() deleted elements.
485 static void tomoyo_collect_entry(void)
488 enum tomoyo_policy_id id;
489 struct tomoyo_policy_namespace *ns;
490 mutex_lock(&tomoyo_policy_lock);
492 struct tomoyo_domain_info *domain;
493 struct tomoyo_domain_info *tmp;
494 list_for_each_entry_safe(domain, tmp, &tomoyo_domain_list,
496 tomoyo_collect_acl(&domain->acl_info_list);
497 if (!domain->is_deleted || atomic_read(&domain->users))
499 tomoyo_try_to_gc(TOMOYO_ID_DOMAIN, &domain->list);
502 list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
503 for (id = 0; id < TOMOYO_MAX_POLICY; id++)
504 tomoyo_collect_member(id, &ns->policy_list[id]);
505 for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++)
506 tomoyo_collect_acl(&ns->acl_group[i]);
509 struct tomoyo_shared_acl_head *ptr;
510 struct tomoyo_shared_acl_head *tmp;
511 list_for_each_entry_safe(ptr, tmp, &tomoyo_condition_list,
513 if (atomic_read(&ptr->users) > 0)
515 atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS);
516 tomoyo_try_to_gc(TOMOYO_ID_CONDITION, &ptr->list);
519 list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
520 for (i = 0; i < TOMOYO_MAX_GROUP; i++) {
521 struct list_head *list = &ns->group_list[i];
522 struct tomoyo_group *group;
523 struct tomoyo_group *tmp;
526 id = TOMOYO_ID_PATH_GROUP;
529 id = TOMOYO_ID_NUMBER_GROUP;
532 id = TOMOYO_ID_ADDRESS_GROUP;
535 list_for_each_entry_safe(group, tmp, list, head.list) {
536 tomoyo_collect_member(id, &group->member_list);
537 if (!list_empty(&group->member_list) ||
538 atomic_read(&group->head.users) > 0)
540 atomic_set(&group->head.users,
541 TOMOYO_GC_IN_PROGRESS);
542 tomoyo_try_to_gc(TOMOYO_ID_GROUP,
547 for (i = 0; i < TOMOYO_MAX_HASH; i++) {
548 struct list_head *list = &tomoyo_name_list[i];
549 struct tomoyo_shared_acl_head *ptr;
550 struct tomoyo_shared_acl_head *tmp;
551 list_for_each_entry_safe(ptr, tmp, list, list) {
552 if (atomic_read(&ptr->users) > 0)
554 atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS);
555 tomoyo_try_to_gc(TOMOYO_ID_NAME, &ptr->list);
558 mutex_unlock(&tomoyo_policy_lock);
562 * tomoyo_gc_thread - Garbage collector thread function.
568 static int tomoyo_gc_thread(void *unused)
570 /* Garbage collector thread is exclusive. */
571 static DEFINE_MUTEX(tomoyo_gc_mutex);
572 if (!mutex_trylock(&tomoyo_gc_mutex))
574 tomoyo_collect_entry();
576 struct tomoyo_io_buffer *head;
577 struct tomoyo_io_buffer *tmp;
579 spin_lock(&tomoyo_io_buffer_list_lock);
580 list_for_each_entry_safe(head, tmp, &tomoyo_io_buffer_list,
584 list_del(&head->list);
585 kfree(head->read_buf);
586 kfree(head->write_buf);
589 spin_unlock(&tomoyo_io_buffer_list_lock);
591 mutex_unlock(&tomoyo_gc_mutex);
593 /* This acts as do_exit(0). */
598 * tomoyo_notify_gc - Register/unregister /sys/kernel/security/tomoyo/ users.
600 * @head: Pointer to "struct tomoyo_io_buffer".
601 * @is_register: True if register, false if unregister.
605 void tomoyo_notify_gc(struct tomoyo_io_buffer *head, const bool is_register)
607 bool is_write = false;
609 spin_lock(&tomoyo_io_buffer_list_lock);
612 list_add(&head->list, &tomoyo_io_buffer_list);
614 is_write = head->write_buf != NULL;
615 if (!--head->users) {
616 list_del(&head->list);
617 kfree(head->read_buf);
618 kfree(head->write_buf);
622 spin_unlock(&tomoyo_io_buffer_list_lock);
624 struct task_struct *task = kthread_create(tomoyo_gc_thread,
628 wake_up_process(task);