Fix: sessiond: notification: leak of condition on duplicate subscription

An lttng_condition is leaked when a notification channel client attempts
to subscribe to a condition she is already subscribed to.

Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3474ba07046c75bc3cfc2c32501d77b3ea880d33

diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c
index c9847d032b372f2ad5b8cea23fc21a0679da5e3f..414e5dd8aec0afd90a685eb1a23a53f315b2e554 100644 (file)
--- a/src/bin/lttng-sessiond/notification-thread-events.c
+++ b/src/bin/lttng-sessiond/notification-thread-events.c
@@ -1134,9 +1134,11 @@ int notification_thread_client_subscribe(struct notification_client *client,
         */
        CDS_INIT_LIST_HEAD(&condition_list_element->node);
        condition_list_element->condition = condition;
+       condition = NULL;
        cds_list_add(&condition_list_element->node, &client->condition_list);
 
-       client_list = get_client_list_from_condition(state, condition);
+       client_list = get_client_list_from_condition(
+                       state, condition_list_element->condition);
        if (!client_list) {
                /*
                 * No notification-emiting trigger registered with this
@@ -1160,7 +1162,7 @@ int notification_thread_client_subscribe(struct notification_client *client,
        pthread_mutex_lock(&client_list->lock);
        cds_list_for_each_entry(trigger_ht_element,
                        &client_list->triggers_list, client_list_trigger_node) {
-               if (evaluate_condition_for_client(trigger_ht_element->trigger, condition,
+               if (evaluate_condition_for_client(trigger_ht_element->trigger, condition_list_element->condition,
                                client, state)) {
                        WARN("[notification-thread] Evaluation of a condition on client subscription failed, aborting.");
                        ret = -1;
@@ -1189,10 +1191,12 @@ end:
        if (client_list) {
                notification_client_list_put(client_list);
        }
+       lttng_condition_destroy(condition);
        return ret;
 error:
        free(condition_list_element);
        free(client_list_element);
+       lttng_condition_destroy(condition);
        return ret;
 }
 
@@ -3862,6 +3866,7 @@ int client_handle_message_subscription(
                goto end;
        }
 
+       /* Ownership of condition is always transferred. */
        if (msg_type == LTTNG_NOTIFICATION_CHANNEL_MESSAGE_TYPE_SUBSCRIBE) {
                ret = notification_thread_client_subscribe(
                                client, condition, state, &status);