The following commit has been merged in the master branch: commit c78296665c3d81f040117432ab9e1cb125521b0c Author: Sven Eckelmann sven@narfation.org Date: Fri Feb 26 17:56:13 2016 +0100

batman-adv: Check skb size before using encapsulated ETH+VLAN header

The encapsulated ethernet and VLAN header may be outside the received ethernet frame. Thus the skb buffer size has to be checked before it can be parsed to find out if it encapsulates another batman-adv packet.

Fixes: 420193573f11 ("batman-adv: softif bridge loop avoidance") Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli a@unstable.cc

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 0710379..8a136b6 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -408,11 +408,17 @@ void batadv_interface_rx(struct net_device *soft_iface, */ nf_reset(skb);

+ if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) + goto dropped; + vid = batadv_get_vid(skb, 0); ethhdr = eth_hdr(skb);

switch (ntohs(ethhdr->h_proto)) { case ETH_P_8021Q: + if (!pskb_may_pull(skb, VLAN_ETH_HLEN)) + goto dropped; + vhdr = (struct vlan_ethhdr *)skb->data;

if (vhdr->h_vlan_encapsulated_proto != ethertype) @@ -424,8 +430,6 @@ void batadv_interface_rx(struct net_device *soft_iface, }

/* skb->dev & skb->pkt_type are set here */ - if (unlikely(!pskb_may_pull(skb, ETH_HLEN))) - goto dropped; skb->protocol = eth_type_trans(skb, soft_iface);

/* should not be necessary anymore as we use skb_pull_rcsum()