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: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/security/tomoyo/domain.c b/security/tomoyo/domain.c
index 50f6e79..a07ca6d 100644
--- a/security/tomoyo/domain.c
+++ b/security/tomoyo/domain.c
@@ -483,6 +483,136 @@
}
/*
+ * 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
* the current process will belong to after execve() succeeds is calculated
@@ -732,6 +862,23 @@
}
}
+ /* 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)