3.18-stable review patch. If anyone has any objections, please let me know.
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From: Matthias Schiffer <mschiffer@xxxxxxxxxxxxxxxxxxxx>
[ Upstream commit 6f27d2c2a8c236d296201c19abb8533ec20d212b ]
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 <mschiffer@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx>
Signed-off-by: Simon Wunderlich <sw@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/batman-adv/distributed-arp-table.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -343,7 +343,7 @@ static void batadv_dbg_arp(struct batadv
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;
