Commit 1084307c authored by Tetsuo Handa's avatar Tetsuo Handa Committed by James Morris
Browse files

TOMOYO: Add pathname aggregation support.



This patch allows users to aggregate programs which provide similar
functionality (e.g. /usr/bin/vi and /usr/bin/emacs ).
Signed-off-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarJames Morris <jmorris@namei.org>
parent 3f629636
......@@ -1141,6 +1141,8 @@ static int tomoyo_write_exception_policy(struct tomoyo_io_buffer *head)
if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN))
return tomoyo_write_domain_initializer_policy(data, true,
is_delete);
if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_AGGREGATOR))
return tomoyo_write_aggregator_policy(data, is_delete);
if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALIAS))
return tomoyo_write_alias_policy(data, is_delete);
if (tomoyo_str_starts(&data, TOMOYO_KEYWORD_ALLOW_READ))
......@@ -1196,6 +1198,8 @@ static int tomoyo_read_exception_policy(struct tomoyo_io_buffer *head)
head->read_var2 = NULL;
head->read_step = 6;
case 6:
if (!tomoyo_read_aggregator_policy(head))
break;
head->read_var2 = NULL;
head->read_step = 7;
case 7:
......
......@@ -46,6 +46,7 @@ enum tomoyo_mode_index {
};
/* Keywords for ACLs. */
#define TOMOYO_KEYWORD_AGGREGATOR "aggregator "
#define TOMOYO_KEYWORD_ALIAS "alias "
#define TOMOYO_KEYWORD_ALLOW_MOUNT "allow_mount "
#define TOMOYO_KEYWORD_ALLOW_READ "allow_read "
......@@ -592,6 +593,24 @@ struct tomoyo_domain_keeper_entry {
bool is_last_name;
};
/*
* tomoyo_aggregator_entry is a structure which is used for holding
* "aggregator" entries.
* It has following fields.
*
* (1) "list" which is linked to tomoyo_aggregator_list .
* (2) "original_name" which is originally requested name.
* (3) "aggregated_name" which is name to rewrite.
* (4) "is_deleted" is a bool which is true if marked as deleted, false
* otherwise.
*/
struct tomoyo_aggregator_entry {
struct list_head list;
const struct tomoyo_path_info *original_name;
const struct tomoyo_path_info *aggregated_name;
bool is_deleted;
};
/*
* tomoyo_alias_entry is a structure which is used for holding "alias" entries.
* It has following fields.
......@@ -693,6 +712,8 @@ bool tomoyo_print_number_union(struct tomoyo_io_buffer *head,
const struct tomoyo_number_union *ptr);
bool tomoyo_parse_number_union(char *data, struct tomoyo_number_union *num);
/* Read "aggregator" entry in exception policy. */
bool tomoyo_read_aggregator_policy(struct tomoyo_io_buffer *head);
/* Read "alias" entry in exception policy. */
bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head);
/*
......@@ -730,6 +751,8 @@ int tomoyo_init_request_info(struct tomoyo_request_info *r,
/* Check permission for mount operation. */
int tomoyo_mount_permission(char *dev_name, struct path *path, char *type,
unsigned long flags, void *data_page);
/* Create "aggregator" entry in exception policy. */
int tomoyo_write_aggregator_policy(char *data, const bool is_delete);
/* Create "alias" entry in exception policy. */
int tomoyo_write_alias_policy(char *data, const bool is_delete);
/*
......@@ -857,6 +880,7 @@ extern struct list_head tomoyo_path_group_list;
extern struct list_head tomoyo_number_group_list;
extern struct list_head tomoyo_domain_initializer_list;
extern struct list_head tomoyo_domain_keeper_list;
extern struct list_head tomoyo_aggregator_list;
extern struct list_head tomoyo_alias_list;
extern struct list_head tomoyo_globally_readable_list;
extern struct list_head tomoyo_pattern_list;
......@@ -1036,6 +1060,14 @@ static inline bool tomoyo_is_same_domain_keeper_entry
&& p1->program == p2->program;
}
static inline bool tomoyo_is_same_aggregator_entry
(const struct tomoyo_aggregator_entry *p1,
const struct tomoyo_aggregator_entry *p2)
{
return p1->original_name == p2->original_name &&
p1->aggregated_name == p2->aggregated_name;
}
static inline bool tomoyo_is_same_alias_entry
(const struct tomoyo_alias_entry *p1, const struct tomoyo_alias_entry *p2)
{
......
......@@ -482,6 +482,136 @@ static bool tomoyo_is_domain_keeper(const struct tomoyo_path_info *domainname,
return flag;
}
/*
* tomoyo_aggregator_list is used for holding list of rewrite table for
* execve() request. Some programs provides similar functionality. This keyword
* allows users to aggregate such programs.
*
* Entries are added by
*
* # echo 'aggregator /usr/bin/vi /./editor' > \
* /sys/kernel/security/tomoyo/exception_policy
* # echo 'aggregator /usr/bin/emacs /./editor' > \
* /sys/kernel/security/tomoyo/exception_policy
*
* and are deleted by
*
* # echo 'delete aggregator /usr/bin/vi /./editor' > \
* /sys/kernel/security/tomoyo/exception_policy
* # echo 'delete aggregator /usr/bin/emacs /./editor' > \
* /sys/kernel/security/tomoyo/exception_policy
*
* and all entries are retrieved by
*
* # grep ^aggregator /sys/kernel/security/tomoyo/exception_policy
*
* In the example above, if /usr/bin/vi or /usr/bin/emacs are executed,
* permission is checked for /./editor and domainname which the current process
* will belong to after execve() succeeds is calculated using /./editor .
*/
LIST_HEAD(tomoyo_aggregator_list);
/**
* tomoyo_update_aggregator_entry - Update "struct tomoyo_aggregator_entry" list.
*
* @original_name: The original program's name.
* @aggregated_name: The program name to use.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
static int tomoyo_update_aggregator_entry(const char *original_name,
const char *aggregated_name,
const bool is_delete)
{
struct tomoyo_aggregator_entry *ptr;
struct tomoyo_aggregator_entry e = { };
int error = is_delete ? -ENOENT : -ENOMEM;
if (!tomoyo_is_correct_path(original_name) ||
!tomoyo_is_correct_path(aggregated_name))
return -EINVAL;
e.original_name = tomoyo_get_name(original_name);
e.aggregated_name = tomoyo_get_name(aggregated_name);
if (!e.original_name || !e.aggregated_name ||
e.aggregated_name->is_patterned) /* No patterns allowed. */
goto out;
if (mutex_lock_interruptible(&tomoyo_policy_lock))
goto out;
list_for_each_entry_rcu(ptr, &tomoyo_aggregator_list, list) {
if (!tomoyo_is_same_aggregator_entry(ptr, &e))
continue;
ptr->is_deleted = is_delete;
error = 0;
break;
}
if (!is_delete && error) {
struct tomoyo_aggregator_entry *entry =
tomoyo_commit_ok(&e, sizeof(e));
if (entry) {
list_add_tail_rcu(&entry->list,
&tomoyo_aggregator_list);
error = 0;
}
}
mutex_unlock(&tomoyo_policy_lock);
out:
tomoyo_put_name(e.original_name);
tomoyo_put_name(e.aggregated_name);
return error;
}
/**
* tomoyo_read_aggregator_policy - Read "struct tomoyo_aggregator_entry" list.
*
* @head: Pointer to "struct tomoyo_io_buffer".
*
* Returns true on success, false otherwise.
*
* Caller holds tomoyo_read_lock().
*/
bool tomoyo_read_aggregator_policy(struct tomoyo_io_buffer *head)
{
struct list_head *pos;
bool done = true;
list_for_each_cookie(pos, head->read_var2, &tomoyo_aggregator_list) {
struct tomoyo_aggregator_entry *ptr;
ptr = list_entry(pos, struct tomoyo_aggregator_entry, list);
if (ptr->is_deleted)
continue;
done = tomoyo_io_printf(head, TOMOYO_KEYWORD_AGGREGATOR
"%s %s\n", ptr->original_name->name,
ptr->aggregated_name->name);
if (!done)
break;
}
return done;
}
/**
* tomoyo_write_aggregator_policy - Write "struct tomoyo_aggregator_entry" list.
*
* @data: String to parse.
* @is_delete: True if it is a delete request.
*
* Returns 0 on success, negative value otherwise.
*
* Caller holds tomoyo_read_lock().
*/
int tomoyo_write_aggregator_policy(char *data, const bool is_delete)
{
char *cp = strchr(data, ' ');
if (!cp)
return -EINVAL;
*cp++ = '\0';
return tomoyo_update_aggregator_entry(data, cp, is_delete);
}
/*
* tomoyo_alias_list is used for holding list of symlink's pathnames which are
* allowed to be passed to an execve() request. Normally, the domainname which
......@@ -732,6 +862,23 @@ int tomoyo_find_next_domain(struct linux_binprm *bprm)
}
}
/* Check 'aggregator' directive. */
{
struct tomoyo_aggregator_entry *ptr;
list_for_each_entry_rcu(ptr, &tomoyo_aggregator_list, list) {
if (ptr->is_deleted ||
!tomoyo_path_matches_pattern(&rn,
ptr->original_name))
continue;
if (need_kfree)
kfree(rn.name);
need_kfree = false;
/* This is OK because it is read only. */
rn = *ptr->aggregated_name;
break;
}
}
/* Check execute permission. */
retval = tomoyo_check_exec_perm(old_domain, &rn);
if (retval == TOMOYO_RETRY_REQUEST)
......
......@@ -18,6 +18,7 @@ enum tomoyo_gc_id {
TOMOYO_ID_NUMBER_GROUP_MEMBER,
TOMOYO_ID_DOMAIN_INITIALIZER,
TOMOYO_ID_DOMAIN_KEEPER,
TOMOYO_ID_AGGREGATOR,
TOMOYO_ID_ALIAS,
TOMOYO_ID_GLOBALLY_READABLE,
TOMOYO_ID_PATTERN,
......@@ -77,6 +78,12 @@ static void tomoyo_del_domain_keeper(struct tomoyo_domain_keeper_entry *ptr)
tomoyo_put_name(ptr->program);
}
static void tomoyo_del_aggregator(struct tomoyo_aggregator_entry *ptr)
{
tomoyo_put_name(ptr->original_name);
tomoyo_put_name(ptr->aggregated_name);
}
static void tomoyo_del_alias(struct tomoyo_alias_entry *ptr)
{
tomoyo_put_name(ptr->original_name);
......@@ -263,6 +270,17 @@ static void tomoyo_collect_entry(void)
break;
}
}
{
struct tomoyo_aggregator_entry *ptr;
list_for_each_entry_rcu(ptr, &tomoyo_aggregator_list, list) {
if (!ptr->is_deleted)
continue;
if (tomoyo_add_to_gc(TOMOYO_ID_AGGREGATOR, ptr))
list_del_rcu(&ptr->list);
else
break;
}
}
{
struct tomoyo_alias_entry *ptr;
list_for_each_entry_rcu(ptr, &tomoyo_alias_list, list) {
......@@ -417,6 +435,9 @@ static void tomoyo_kfree_entry(void)
case TOMOYO_ID_DOMAIN_KEEPER:
tomoyo_del_domain_keeper(p->element);
break;
case TOMOYO_ID_AGGREGATOR:
tomoyo_del_aggregator(p->element);
break;
case TOMOYO_ID_ALIAS:
tomoyo_del_alias(p->element);
break;
......
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