From ca064bd89363a6e7e71b1c5226ff1b718957a9d4 Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Mon, 19 Oct 2015 10:30:05 +0200 Subject: xfrm: Fix pmtu discovery for local generated packets. Commit 044a832a777 ("xfrm: Fix local error reporting crash with interfamily tunnels") moved the setting of skb->protocol behind the last access of the inner mode family to fix an interfamily crash. Unfortunately now skb->protocol might not be set at all, so we fail dispatch to the inner address family. As a reault, the local error handler is not called and the mtu value is not reported back to userspace. We fix this by setting skb->protocol on message size errors before we call xfrm_local_error. Fixes: 044a832a7779c ("xfrm: Fix local error reporting crash with interfamily tunnels") Signed-off-by: Steffen Klassert --- net/ipv4/xfrm4_output.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/ipv4') diff --git a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c index 2878dbfffeb7..41a261355662 100644 --- a/net/ipv4/xfrm4_output.c +++ b/net/ipv4/xfrm4_output.c @@ -30,6 +30,8 @@ static int xfrm4_tunnel_check_size(struct sk_buff *skb) mtu = dst_mtu(skb_dst(skb)); if (skb->len > mtu) { + skb->protocol = htons(ETH_P_IP); + if (skb->sk) xfrm_local_error(skb, mtu); else -- cgit v1.2.3