batman-adv: avoid NULL dereferences and fix if check

[ Upstream commit 0d1644919578db525b9a7b6c8197ce02adbfce26 ]

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@meshcoding.com>
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index 36b9ae61f5e8d5a72051564c64b2675ebc47d5d4..2393ea72d65fca15ca306f3b71c8040b59146056 100644 (file)
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -812,7 +812,7 @@ 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)) {