[PATCH 3.16.y-ckt 063/126] batman-adv: avoid NULL dereferences and fix if check

[Luis Henriques]

3.16.7-ckt5 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Antonio Quartulli <antonio at meshcoding.com>

commit 0d1644919578db525b9a7b6c8197ce02adbfce26 upstream.

Gateway having bandwidth_down equal to zero are not accepted
at all and so never added to the Gateway list.
For this reason checking the bandwidth_down member in
batadv_gw_out_of_range() is useless.

This is probably a copy/paste error and this check was supposed
to be "!gw_node" only. Moreover, the way the check is written
now may also lead to a NULL dereference.

Fix this by rewriting the if-condition properly.

Introduced by 414254e342a0d58144de40c3da777521ebaeeb07
("batman-adv: tvlv - gateway download/upload bandwidth container")

Signed-off-by: Antonio Quartulli <antonio at meshcoding.com>
Reported-by: David Binderman <dcb314 at hotmail.com>
Signed-off-by: Marek Lindner <mareklindner at neomailbox.ch>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/batman-adv/gateway_client.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 90cff585b37d..e0bcf9e84273 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -810,7 +810,7 @@ bool batadv_gw_out_of_range(struct batadv_priv *bat_priv,
 		goto out;
 
 	gw_node = batadv_gw_node_get(bat_priv, orig_dst_node);
-	if (!gw_node->bandwidth_down == 0)
+	if (!gw_node)
 		goto out;
 
 	switch (atomic_read(&bat_priv->gw_mode)) {
-- 
2.1.4