[PATCH net 5/6] batman-adv: bla: reacquire gw address after skb realloc

[Simon Wunderlich <sw@simonwunderlich.de>]

From: Sven Eckelmann <sven@narfation.org>

The pskb_may_pull() called by batadv_bla_is_backbone_gw() could reallocate
the buffer behind the skb. Variables which were pointing to the old buffer
need to be reassigned to avoid an use-after-free.

Cc: stable@vger.kernel.org
Fixes: 9e794b6bf4a2 ("batman-adv: drop unicast packets from other backbone gw")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/routing.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 2cc2307a41702..bbd40fe3a8e59 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -1029,6 +1029,7 @@ int batadv_recv_unicast_packet(struct sk_buff *skb,
 							  hdr_size);
 			batadv_orig_node_put(orig_node_gw);
 			if (is_gw) {
+				orig_addr_gw = eth_hdr(skb)->h_source;
 				batadv_dbg(BATADV_DBG_BLA, bat_priv,
 					   "%s(): Dropped unicast pkt received from another backbone gw %pM.\n",
 					   __func__, orig_addr_gw);
-- 
2.47.3