3.16.37-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Sven Eckelmann <[email protected]> commit 3b55e4422087f9f7b241031d758a0c65584e4297 upstream. 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 <[email protected]> Signed-off-by: Marek Lindner <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- net/batman-adv/routing.c | 1 + 1 file changed, 1 insertion(+) --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -344,6 +344,7 @@ int batadv_recv_icmp_packet(struct sk_bu 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)
