Fix: sessiond: ust-registry: dereference of NULL pointer on allocation failure

Coverity reports:
1445771 Dereference after null check
Either the check against null is unnecessary, or there may be a null pointer dereference.
In ust_registry_channel_add: Pointer is checked against null but then dereferenced anyway (CWE-476)

Reported-by: Coverity Scan
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I3976e0d7b059b47ca233bc9a20585eff2e1290fc

diff --git a/src/bin/lttng-sessiond/ust-registry.c b/src/bin/lttng-sessiond/ust-registry.c
index 2e33b9575f9d1e298af8eb539c510997c2e1588c..1b1e65eba1327f06e90344020e490784363ec694 100644 (file)
--- a/src/bin/lttng-sessiond/ust-registry.c
+++ b/src/bin/lttng-sessiond/ust-registry.c
@@ -739,13 +739,16 @@ static void destroy_channel(struct ust_registry_channel *chan, bool notif)
                }
        }
 
-       rcu_read_lock();
-       /* Destroy all event associated with this registry. */
-       cds_lfht_for_each_entry(chan->ht->ht, &iter.iter, event, node.node) {
-               /* Delete the node from the ht and free it. */
-               ust_registry_destroy_event(chan, event);
+       if (chan->ht) {
+               rcu_read_lock();
+               /* Destroy all event associated with this registry. */
+               cds_lfht_for_each_entry(
+                               chan->ht->ht, &iter.iter, event, node.node) {
+                       /* Delete the node from the ht and free it. */
+                       ust_registry_destroy_event(chan, event);
+               }
+               rcu_read_unlock();
        }
-       rcu_read_unlock();
        call_rcu(&chan->rcu_head, destroy_channel_rcu);
 }