From: Matthias Schiffer Date: Fri, 16 Mar 2018 10:29:10 +0000 (+0100) Subject: batman-adv: fix header size check in batadv_dbg_arp() X-Git-Tag: v4.16-rc7~23^2~11^2~2 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=6f27d2c2a8c236d296201c19abb8533ec20d212b;p=users%2Fhch%2Fmisc.git 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: be1db4f6615b ("batman-adv: make the Distributed ARP Table vlan aware") Signed-off-by: Matthias Schiffer Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 9703c791ffc5..87cd962d28d5 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -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;