[3/5] batman-adv: fix header size check in batadv_dbg_arp()

Message ID 20180319163726.10921-4-sw@simonwunderlich.de (mailing list archive)
State Not Applicable, archived
Delegated to: Simon Wunderlich
Headers
Series [1/5] batman-adv: Fix multicast packet loss with a single WANT_ALL_IPV4/6 flag |

Commit Message

Simon Wunderlich March 19, 2018, 4:37 p.m. UTC
  From: Matthias Schiffer <mschiffer@universe-factory.net>

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@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
---
 net/batman-adv/distributed-arp-table.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
  

Patch

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;