path: root/net
diff options
authorSven Eckelmann <>2016-06-26 11:16:12 +0200
committerDavid S. Miller <>2016-06-29 04:01:48 -0400
commit3b55e4422087f9f7b241031d758a0c65584e4297 (patch)
tree4e5911b53be006d88af805e05eb1e2b6cf6b1535 /net
parentbaceced93274ff2f846eae991664f9094425ffa8 (diff)
batman-adv: Fix ICMP RR ethernet access after skb_linearize
The skb_linearize may reallocate the skb. This makes the calculated pointer for ethhdr invalid. But it the pointer is used later to fill in the RR field of the batadv_icmp_packet_rr packet. Instead re-evaluate eth_hdr after the skb_linearize+skb_cow to fix the pointer and avoid the invalid read. Fixes: da6b8c20a5b8 ("batman-adv: generalize batman-adv icmp packet handling") Signed-off-by: Sven Eckelmann <> Signed-off-by: Marek Lindner <> Signed-off-by: David S. Miller <>
Diffstat (limited to 'net')
1 files changed, 1 insertions, 0 deletions
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index e3857ed4057f..6c2901a86230 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -374,6 +374,7 @@ int batadv_recv_icmp_packet(struct sk_buff *skb,
if (skb_cow(skb, ETH_HLEN) < 0)
goto out;
+ ethhdr = eth_hdr(skb);
icmph = (struct batadv_icmp_header *)skb->data;
icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph;
if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN)