From: Andreas Pape <apape@phoenixcontact.com>
Date: Fri, 19 May 2017 10:01:42 +0200
Subject: batman-adv: fix memory leak when dropping packet from other gateway

The skb must be released in the receive handler since b91a2543b4c1
("batman-adv: Consume skb in receive handlers"). Just returning NET_RX_DROP
will no longer automatically free the memory. This results in memory leaks
when unicast packets from other backbones must be dropped because they
share a common backbone.

Fixes: bfe2a1971f43 ("batman-adv: drop unicast packets from other backbone gw")
Signed-off-by: Andreas Pape <apape@phoenixcontact.com>
[sven@narfation.org: adjust commit message]
Signed-off-by: Sven Eckelmann <sven@narfation.org>

Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/a58feb79ed1447e3e83f3b0b1a23779886869f39

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 5190683424b89d1fa7c86895000bc6656e6a65dd..213cc01ad00392f7cbd4efd9d4796f76691d2d9e 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -988,7 +988,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
 				batadv_dbg(BATADV_DBG_BLA, bat_priv,
 					   "Dropped unicast pkt received from another backbone gw %pM.\n",
 					   orig_addr_gw);
-				return NET_RX_DROP;
+				goto free_skb;
 			}
 		}