batman-adv: fix header size check in batadv_dbg_arp()

Checking for 0 is insufficient: when an SKB without a batadv header, but
with a VLAN header is received, hdr_size will be 4, making the following
code interpret the Ethernet header as a batadv header.

Fixes: be1db4f661 ("batman-adv: make the Distributed ARP Table vlan aware")
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This commit is contained in:
Matthias Schiffer 2018-03-16 11:29:10 +01:00 committed by Simon Wunderlich
parent bc44b78157
commit 6f27d2c2a8
1 changed files with 1 additions and 1 deletions

View File

@ -393,7 +393,7 @@ static void batadv_dbg_arp(struct batadv_priv *bat_priv, struct sk_buff *skb,
batadv_arp_hw_src(skb, hdr_size), &ip_src,
batadv_arp_hw_dst(skb, hdr_size), &ip_dst);
if (hdr_size == 0)
if (hdr_size < sizeof(struct batadv_unicast_packet))
return;
unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data;