From f15ca723c1ebe6c1a06bc95fda6b62cd87b44559 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Thu, 25 Jan 2018 19:03:03 +0100 Subject: net: don't call update_pmtu unconditionally Some dst_ops (e.g. md_dst_ops)) doesn't set this handler. It may result to: "BUG: unable to handle kernel NULL pointer dereference at (null)" Let's add a helper to check if update_pmtu is available before calling it. Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") CC: Roman Kapl CC: Xin Long Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller --- net/ipv4/ip_tunnel.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net/ipv4/ip_tunnel.c') diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 5ddb1cb52bd4..6d21068f9b55 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -520,8 +520,7 @@ static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, else mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; - if (skb_dst(skb)) - skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); + skb_dst_update_pmtu(skb, mtu); if (skb->protocol == htons(ETH_P_IP)) { if (!skb_is_gso(skb) && -- cgit v1.2.3-59-g8ed1b