Bluetooth: BAP: Add missing ep->iso checks

The bt_bap_unicast_client_ep_qos function attempts to access
ep->iso->chan.iso->iso, but where some of the pointers may be
invalid. Add an additional check for these.

Signed-off-by: Emil Gydesen <[email protected]>

Author: Thalley

subsys/bluetooth/audio/bap_unicast_client.c

@@ -1957,7 +1957,9 @@ int bt_bap_unicast_client_ep_qos(struct bt_bap_ep *ep, struct net_buf_simple *bu
 
 	LOG_DBG("ep %p buf %p qos %p", ep, buf, qos);
 
-	if (!ep) {
+	if (ep == NULL || ep->iso == NULL || ep->iso->chan.iso == NULL) {
+		LOG_DBG("Invalid endpoint %p (%p (%p))", ep, ep == NULL ? NULL : ep->iso,
+			(ep == NULL || ep->iso == NULL) ? NULL : ep->iso->chan.iso);
 		return -EINVAL;
 	}