batman-adv: bla: put backbone reference on failed claim hash insert

commit ba9d20e upstream.

When batadv_bla_add_claim() fails to insert a new claim into the hash, it
leaked a reference to the backbone_gw for which the claim was intended.
Call batadv_backbone_gw_put() on the error path to release the reference
and avoid leaking the backbone_gw object.

Cc: stable@kernel.org
Fixes: 3db0dec ("batman-adv: Fix non-atomic bla_claim::backbone_gw access")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: ecsv

net/batman-adv/bridge_loop_avoidance.c

@@ -723,6 +723,7 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv,
 
 		if (unlikely(hash_added != 0)) {
 			/* only local changes happened. */
+			batadv_backbone_gw_put(backbone_gw);
 			kfree(claim);
 			return;
 		}