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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Tetsuo Handa](/assets/img/avatar_default.png)
Commit059d84db
"TOMOYO: Add socket operation restriction support" and commit731d37aa
"TOMOYO: Allow domain transition without execve()." forgot to update tomoyo_domain_quota_is_ok() and tomoyo_del_acl() which results in incorrect quota counting and memory leak. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: James Morris <jmorris@namei.org>
655 lines
17 KiB
C
655 lines
17 KiB
C
/*
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* security/tomoyo/gc.c
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*
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* Copyright (C) 2005-2011 NTT DATA CORPORATION
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*/
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#include "common.h"
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#include <linux/kthread.h>
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#include <linux/slab.h>
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/**
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* tomoyo_memory_free - Free memory for elements.
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*
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* @ptr: Pointer to allocated memory.
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*
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* Returns nothing.
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*
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* Caller holds tomoyo_policy_lock mutex.
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*/
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static inline void tomoyo_memory_free(void *ptr)
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{
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tomoyo_memory_used[TOMOYO_MEMORY_POLICY] -= ksize(ptr);
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kfree(ptr);
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}
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/* The list for "struct tomoyo_io_buffer". */
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static LIST_HEAD(tomoyo_io_buffer_list);
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/* Lock for protecting tomoyo_io_buffer_list. */
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static DEFINE_SPINLOCK(tomoyo_io_buffer_list_lock);
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/**
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* tomoyo_struct_used_by_io_buffer - Check whether the list element is used by /sys/kernel/security/tomoyo/ users or not.
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns true if @element is used by /sys/kernel/security/tomoyo/ users,
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* false otherwise.
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*/
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static bool tomoyo_struct_used_by_io_buffer(const struct list_head *element)
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{
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struct tomoyo_io_buffer *head;
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bool in_use = false;
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spin_lock(&tomoyo_io_buffer_list_lock);
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list_for_each_entry(head, &tomoyo_io_buffer_list, list) {
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head->users++;
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spin_unlock(&tomoyo_io_buffer_list_lock);
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mutex_lock(&head->io_sem);
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if (head->r.domain == element || head->r.group == element ||
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head->r.acl == element || &head->w.domain->list == element)
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in_use = true;
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mutex_unlock(&head->io_sem);
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spin_lock(&tomoyo_io_buffer_list_lock);
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head->users--;
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if (in_use)
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break;
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}
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spin_unlock(&tomoyo_io_buffer_list_lock);
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return in_use;
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}
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/**
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* tomoyo_name_used_by_io_buffer - Check whether the string is used by /sys/kernel/security/tomoyo/ users or not.
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*
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* @string: String to check.
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*
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* Returns true if @string is used by /sys/kernel/security/tomoyo/ users,
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* false otherwise.
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*/
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static bool tomoyo_name_used_by_io_buffer(const char *string)
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{
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struct tomoyo_io_buffer *head;
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const size_t size = strlen(string) + 1;
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bool in_use = false;
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spin_lock(&tomoyo_io_buffer_list_lock);
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list_for_each_entry(head, &tomoyo_io_buffer_list, list) {
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int i;
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head->users++;
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spin_unlock(&tomoyo_io_buffer_list_lock);
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mutex_lock(&head->io_sem);
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for (i = 0; i < TOMOYO_MAX_IO_READ_QUEUE; i++) {
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const char *w = head->r.w[i];
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if (w < string || w > string + size)
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continue;
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in_use = true;
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break;
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}
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mutex_unlock(&head->io_sem);
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spin_lock(&tomoyo_io_buffer_list_lock);
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head->users--;
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if (in_use)
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break;
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}
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spin_unlock(&tomoyo_io_buffer_list_lock);
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return in_use;
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}
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/**
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* tomoyo_del_transition_control - Delete members in "struct tomoyo_transition_control".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static inline void tomoyo_del_transition_control(struct list_head *element)
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{
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struct tomoyo_transition_control *ptr =
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container_of(element, typeof(*ptr), head.list);
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tomoyo_put_name(ptr->domainname);
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tomoyo_put_name(ptr->program);
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}
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/**
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* tomoyo_del_aggregator - Delete members in "struct tomoyo_aggregator".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static inline void tomoyo_del_aggregator(struct list_head *element)
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{
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struct tomoyo_aggregator *ptr =
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container_of(element, typeof(*ptr), head.list);
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tomoyo_put_name(ptr->original_name);
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tomoyo_put_name(ptr->aggregated_name);
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}
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/**
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* tomoyo_del_manager - Delete members in "struct tomoyo_manager".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static inline void tomoyo_del_manager(struct list_head *element)
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{
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struct tomoyo_manager *ptr =
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container_of(element, typeof(*ptr), head.list);
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tomoyo_put_name(ptr->manager);
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}
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/**
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* tomoyo_del_acl - Delete members in "struct tomoyo_acl_info".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static void tomoyo_del_acl(struct list_head *element)
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{
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struct tomoyo_acl_info *acl =
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container_of(element, typeof(*acl), list);
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tomoyo_put_condition(acl->cond);
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switch (acl->type) {
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case TOMOYO_TYPE_PATH_ACL:
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{
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struct tomoyo_path_acl *entry
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= container_of(acl, typeof(*entry), head);
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tomoyo_put_name_union(&entry->name);
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}
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break;
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case TOMOYO_TYPE_PATH2_ACL:
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{
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struct tomoyo_path2_acl *entry
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= container_of(acl, typeof(*entry), head);
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tomoyo_put_name_union(&entry->name1);
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tomoyo_put_name_union(&entry->name2);
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}
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break;
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case TOMOYO_TYPE_PATH_NUMBER_ACL:
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{
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struct tomoyo_path_number_acl *entry
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= container_of(acl, typeof(*entry), head);
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tomoyo_put_name_union(&entry->name);
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tomoyo_put_number_union(&entry->number);
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}
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break;
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case TOMOYO_TYPE_MKDEV_ACL:
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{
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struct tomoyo_mkdev_acl *entry
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= container_of(acl, typeof(*entry), head);
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tomoyo_put_name_union(&entry->name);
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tomoyo_put_number_union(&entry->mode);
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tomoyo_put_number_union(&entry->major);
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tomoyo_put_number_union(&entry->minor);
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}
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break;
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case TOMOYO_TYPE_MOUNT_ACL:
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{
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struct tomoyo_mount_acl *entry
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= container_of(acl, typeof(*entry), head);
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tomoyo_put_name_union(&entry->dev_name);
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tomoyo_put_name_union(&entry->dir_name);
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tomoyo_put_name_union(&entry->fs_type);
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tomoyo_put_number_union(&entry->flags);
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}
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break;
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case TOMOYO_TYPE_ENV_ACL:
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{
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struct tomoyo_env_acl *entry =
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container_of(acl, typeof(*entry), head);
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tomoyo_put_name(entry->env);
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}
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break;
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case TOMOYO_TYPE_INET_ACL:
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{
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struct tomoyo_inet_acl *entry =
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container_of(acl, typeof(*entry), head);
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tomoyo_put_group(entry->address.group);
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tomoyo_put_number_union(&entry->port);
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}
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break;
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case TOMOYO_TYPE_UNIX_ACL:
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{
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struct tomoyo_unix_acl *entry =
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container_of(acl, typeof(*entry), head);
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tomoyo_put_name_union(&entry->name);
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}
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break;
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case TOMOYO_TYPE_MANUAL_TASK_ACL:
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{
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struct tomoyo_task_acl *entry =
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container_of(acl, typeof(*entry), head);
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tomoyo_put_name(entry->domainname);
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}
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break;
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}
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}
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/**
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* tomoyo_del_domain - Delete members in "struct tomoyo_domain_info".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*
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* Caller holds tomoyo_policy_lock mutex.
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*/
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static inline void tomoyo_del_domain(struct list_head *element)
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{
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struct tomoyo_domain_info *domain =
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container_of(element, typeof(*domain), list);
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struct tomoyo_acl_info *acl;
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struct tomoyo_acl_info *tmp;
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/*
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* Since this domain is referenced from neither
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* "struct tomoyo_io_buffer" nor "struct cred"->security, we can delete
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* elements without checking for is_deleted flag.
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*/
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list_for_each_entry_safe(acl, tmp, &domain->acl_info_list, list) {
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tomoyo_del_acl(&acl->list);
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tomoyo_memory_free(acl);
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}
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tomoyo_put_name(domain->domainname);
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}
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/**
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* tomoyo_del_condition - Delete members in "struct tomoyo_condition".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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void tomoyo_del_condition(struct list_head *element)
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{
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struct tomoyo_condition *cond = container_of(element, typeof(*cond),
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head.list);
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const u16 condc = cond->condc;
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const u16 numbers_count = cond->numbers_count;
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const u16 names_count = cond->names_count;
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const u16 argc = cond->argc;
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const u16 envc = cond->envc;
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unsigned int i;
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const struct tomoyo_condition_element *condp
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= (const struct tomoyo_condition_element *) (cond + 1);
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struct tomoyo_number_union *numbers_p
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= (struct tomoyo_number_union *) (condp + condc);
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struct tomoyo_name_union *names_p
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= (struct tomoyo_name_union *) (numbers_p + numbers_count);
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const struct tomoyo_argv *argv
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= (const struct tomoyo_argv *) (names_p + names_count);
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const struct tomoyo_envp *envp
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= (const struct tomoyo_envp *) (argv + argc);
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for (i = 0; i < numbers_count; i++)
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tomoyo_put_number_union(numbers_p++);
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for (i = 0; i < names_count; i++)
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tomoyo_put_name_union(names_p++);
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for (i = 0; i < argc; argv++, i++)
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tomoyo_put_name(argv->value);
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for (i = 0; i < envc; envp++, i++) {
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tomoyo_put_name(envp->name);
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tomoyo_put_name(envp->value);
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}
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}
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/**
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* tomoyo_del_name - Delete members in "struct tomoyo_name".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static inline void tomoyo_del_name(struct list_head *element)
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{
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/* Nothing to do. */
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}
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/**
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* tomoyo_del_path_group - Delete members in "struct tomoyo_path_group".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static inline void tomoyo_del_path_group(struct list_head *element)
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{
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struct tomoyo_path_group *member =
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container_of(element, typeof(*member), head.list);
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tomoyo_put_name(member->member_name);
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}
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/**
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* tomoyo_del_group - Delete "struct tomoyo_group".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static inline void tomoyo_del_group(struct list_head *element)
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{
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struct tomoyo_group *group =
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container_of(element, typeof(*group), head.list);
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tomoyo_put_name(group->group_name);
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}
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/**
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* tomoyo_del_address_group - Delete members in "struct tomoyo_address_group".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static inline void tomoyo_del_address_group(struct list_head *element)
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{
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/* Nothing to do. */
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}
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/**
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* tomoyo_del_number_group - Delete members in "struct tomoyo_number_group".
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*
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static inline void tomoyo_del_number_group(struct list_head *element)
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{
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/* Nothing to do. */
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}
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/**
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* tomoyo_try_to_gc - Try to kfree() an entry.
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*
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* @type: One of values in "enum tomoyo_policy_id".
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* @element: Pointer to "struct list_head".
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*
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* Returns nothing.
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*
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* Caller holds tomoyo_policy_lock mutex.
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*/
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static void tomoyo_try_to_gc(const enum tomoyo_policy_id type,
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struct list_head *element)
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{
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/*
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* __list_del_entry() guarantees that the list element became no longer
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* reachable from the list which the element was originally on (e.g.
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* tomoyo_domain_list). Also, synchronize_srcu() guarantees that the
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* list element became no longer referenced by syscall users.
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*/
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__list_del_entry(element);
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mutex_unlock(&tomoyo_policy_lock);
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synchronize_srcu(&tomoyo_ss);
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/*
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* However, there are two users which may still be using the list
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* element. We need to defer until both users forget this element.
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*
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* Don't kfree() until "struct tomoyo_io_buffer"->r.{domain,group,acl}
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* and "struct tomoyo_io_buffer"->w.domain forget this element.
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*/
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if (tomoyo_struct_used_by_io_buffer(element))
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goto reinject;
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switch (type) {
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case TOMOYO_ID_TRANSITION_CONTROL:
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tomoyo_del_transition_control(element);
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break;
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case TOMOYO_ID_MANAGER:
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tomoyo_del_manager(element);
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break;
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case TOMOYO_ID_AGGREGATOR:
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tomoyo_del_aggregator(element);
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break;
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case TOMOYO_ID_GROUP:
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tomoyo_del_group(element);
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break;
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case TOMOYO_ID_PATH_GROUP:
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tomoyo_del_path_group(element);
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break;
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case TOMOYO_ID_ADDRESS_GROUP:
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tomoyo_del_address_group(element);
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break;
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case TOMOYO_ID_NUMBER_GROUP:
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tomoyo_del_number_group(element);
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break;
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case TOMOYO_ID_CONDITION:
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tomoyo_del_condition(element);
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break;
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case TOMOYO_ID_NAME:
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/*
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* Don't kfree() until all "struct tomoyo_io_buffer"->r.w[]
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* forget this element.
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*/
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if (tomoyo_name_used_by_io_buffer
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(container_of(element, typeof(struct tomoyo_name),
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head.list)->entry.name))
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goto reinject;
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tomoyo_del_name(element);
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break;
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case TOMOYO_ID_ACL:
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tomoyo_del_acl(element);
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break;
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case TOMOYO_ID_DOMAIN:
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/*
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* Don't kfree() until all "struct cred"->security forget this
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* element.
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*/
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if (atomic_read(&container_of
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(element, typeof(struct tomoyo_domain_info),
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list)->users))
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goto reinject;
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break;
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case TOMOYO_MAX_POLICY:
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break;
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}
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mutex_lock(&tomoyo_policy_lock);
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if (type == TOMOYO_ID_DOMAIN)
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tomoyo_del_domain(element);
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tomoyo_memory_free(element);
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return;
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reinject:
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/*
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* We can safely reinject this element here bacause
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* (1) Appending list elements and removing list elements are protected
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* by tomoyo_policy_lock mutex.
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* (2) Only this function removes list elements and this function is
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* exclusively executed by tomoyo_gc_mutex mutex.
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* are true.
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*/
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mutex_lock(&tomoyo_policy_lock);
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list_add_rcu(element, element->prev);
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}
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/**
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* tomoyo_collect_member - Delete elements with "struct tomoyo_acl_head".
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*
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* @id: One of values in "enum tomoyo_policy_id".
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* @member_list: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static void tomoyo_collect_member(const enum tomoyo_policy_id id,
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struct list_head *member_list)
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{
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struct tomoyo_acl_head *member;
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struct tomoyo_acl_head *tmp;
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list_for_each_entry_safe(member, tmp, member_list, list) {
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if (!member->is_deleted)
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continue;
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member->is_deleted = TOMOYO_GC_IN_PROGRESS;
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tomoyo_try_to_gc(id, &member->list);
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}
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}
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/**
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* tomoyo_collect_acl - Delete elements in "struct tomoyo_domain_info".
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*
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* @list: Pointer to "struct list_head".
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*
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* Returns nothing.
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*/
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static void tomoyo_collect_acl(struct list_head *list)
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{
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struct tomoyo_acl_info *acl;
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struct tomoyo_acl_info *tmp;
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list_for_each_entry_safe(acl, tmp, list, list) {
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if (!acl->is_deleted)
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continue;
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acl->is_deleted = TOMOYO_GC_IN_PROGRESS;
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tomoyo_try_to_gc(TOMOYO_ID_ACL, &acl->list);
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}
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}
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/**
|
|
* tomoyo_collect_entry - Try to kfree() deleted elements.
|
|
*
|
|
* Returns nothing.
|
|
*/
|
|
static void tomoyo_collect_entry(void)
|
|
{
|
|
int i;
|
|
enum tomoyo_policy_id id;
|
|
struct tomoyo_policy_namespace *ns;
|
|
mutex_lock(&tomoyo_policy_lock);
|
|
{
|
|
struct tomoyo_domain_info *domain;
|
|
struct tomoyo_domain_info *tmp;
|
|
list_for_each_entry_safe(domain, tmp, &tomoyo_domain_list,
|
|
list) {
|
|
tomoyo_collect_acl(&domain->acl_info_list);
|
|
if (!domain->is_deleted || atomic_read(&domain->users))
|
|
continue;
|
|
tomoyo_try_to_gc(TOMOYO_ID_DOMAIN, &domain->list);
|
|
}
|
|
}
|
|
list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
|
|
for (id = 0; id < TOMOYO_MAX_POLICY; id++)
|
|
tomoyo_collect_member(id, &ns->policy_list[id]);
|
|
for (i = 0; i < TOMOYO_MAX_ACL_GROUPS; i++)
|
|
tomoyo_collect_acl(&ns->acl_group[i]);
|
|
}
|
|
{
|
|
struct tomoyo_shared_acl_head *ptr;
|
|
struct tomoyo_shared_acl_head *tmp;
|
|
list_for_each_entry_safe(ptr, tmp, &tomoyo_condition_list,
|
|
list) {
|
|
if (atomic_read(&ptr->users) > 0)
|
|
continue;
|
|
atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS);
|
|
tomoyo_try_to_gc(TOMOYO_ID_CONDITION, &ptr->list);
|
|
}
|
|
}
|
|
list_for_each_entry(ns, &tomoyo_namespace_list, namespace_list) {
|
|
for (i = 0; i < TOMOYO_MAX_GROUP; i++) {
|
|
struct list_head *list = &ns->group_list[i];
|
|
struct tomoyo_group *group;
|
|
struct tomoyo_group *tmp;
|
|
switch (i) {
|
|
case 0:
|
|
id = TOMOYO_ID_PATH_GROUP;
|
|
break;
|
|
case 1:
|
|
id = TOMOYO_ID_NUMBER_GROUP;
|
|
break;
|
|
default:
|
|
id = TOMOYO_ID_ADDRESS_GROUP;
|
|
break;
|
|
}
|
|
list_for_each_entry_safe(group, tmp, list, head.list) {
|
|
tomoyo_collect_member(id, &group->member_list);
|
|
if (!list_empty(&group->member_list) ||
|
|
atomic_read(&group->head.users) > 0)
|
|
continue;
|
|
atomic_set(&group->head.users,
|
|
TOMOYO_GC_IN_PROGRESS);
|
|
tomoyo_try_to_gc(TOMOYO_ID_GROUP,
|
|
&group->head.list);
|
|
}
|
|
}
|
|
}
|
|
for (i = 0; i < TOMOYO_MAX_HASH; i++) {
|
|
struct list_head *list = &tomoyo_name_list[i];
|
|
struct tomoyo_shared_acl_head *ptr;
|
|
struct tomoyo_shared_acl_head *tmp;
|
|
list_for_each_entry_safe(ptr, tmp, list, list) {
|
|
if (atomic_read(&ptr->users) > 0)
|
|
continue;
|
|
atomic_set(&ptr->users, TOMOYO_GC_IN_PROGRESS);
|
|
tomoyo_try_to_gc(TOMOYO_ID_NAME, &ptr->list);
|
|
}
|
|
}
|
|
mutex_unlock(&tomoyo_policy_lock);
|
|
}
|
|
|
|
/**
|
|
* tomoyo_gc_thread - Garbage collector thread function.
|
|
*
|
|
* @unused: Unused.
|
|
*
|
|
* Returns 0.
|
|
*/
|
|
static int tomoyo_gc_thread(void *unused)
|
|
{
|
|
/* Garbage collector thread is exclusive. */
|
|
static DEFINE_MUTEX(tomoyo_gc_mutex);
|
|
if (!mutex_trylock(&tomoyo_gc_mutex))
|
|
goto out;
|
|
tomoyo_collect_entry();
|
|
{
|
|
struct tomoyo_io_buffer *head;
|
|
struct tomoyo_io_buffer *tmp;
|
|
|
|
spin_lock(&tomoyo_io_buffer_list_lock);
|
|
list_for_each_entry_safe(head, tmp, &tomoyo_io_buffer_list,
|
|
list) {
|
|
if (head->users)
|
|
continue;
|
|
list_del(&head->list);
|
|
kfree(head->read_buf);
|
|
kfree(head->write_buf);
|
|
kfree(head);
|
|
}
|
|
spin_unlock(&tomoyo_io_buffer_list_lock);
|
|
}
|
|
mutex_unlock(&tomoyo_gc_mutex);
|
|
out:
|
|
/* This acts as do_exit(0). */
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* tomoyo_notify_gc - Register/unregister /sys/kernel/security/tomoyo/ users.
|
|
*
|
|
* @head: Pointer to "struct tomoyo_io_buffer".
|
|
* @is_register: True if register, false if unregister.
|
|
*
|
|
* Returns nothing.
|
|
*/
|
|
void tomoyo_notify_gc(struct tomoyo_io_buffer *head, const bool is_register)
|
|
{
|
|
bool is_write = false;
|
|
|
|
spin_lock(&tomoyo_io_buffer_list_lock);
|
|
if (is_register) {
|
|
head->users = 1;
|
|
list_add(&head->list, &tomoyo_io_buffer_list);
|
|
} else {
|
|
is_write = head->write_buf != NULL;
|
|
if (!--head->users) {
|
|
list_del(&head->list);
|
|
kfree(head->read_buf);
|
|
kfree(head->write_buf);
|
|
kfree(head);
|
|
}
|
|
}
|
|
spin_unlock(&tomoyo_io_buffer_list_lock);
|
|
if (is_write) {
|
|
struct task_struct *task = kthread_create(tomoyo_gc_thread,
|
|
NULL,
|
|
"GC for TOMOYO");
|
|
if (!IS_ERR(task))
|
|
wake_up_process(task);
|
|
}
|
|
}
|