Hi Nikolay, On Thu, Apr 14, 2022 at 12:45 PM Nikolay Aleksandrov <razor@xxxxxxxxxxxxx> wrote: > When we try to transmit an skb with md_dst attached through wireguard > we hit a null pointer dereference[1] in wg_xmit() due to the use of > dst_mtu() which calls into dst_blackhole_mtu() which in turn tries to > dereference dst->dev. Since wireguard doesn't use md_dsts we should use > skb_valid_dst() which checks for DST_METADATA flag and if it's set then > fallback to wireguard's device mtu. That gives us the best chance of > transmitting the packet, otherwise if the blackhole netdev is used we'd > get ETH_MIN_MTU. Thanks for the patch. Will queue up this patch #1 in the wireguard tree and send it out to net.git not before too long. Jason
