From caf3f2676aaad395903d24a54e22f8ac4bc4823d Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 4 Oct 2015 21:08:08 -0700 Subject: [PATCH] inet: ip_skb_dst_mtu() should use sk_fullsock() SYN_RECV & TIMEWAIT sockets are not full blown, do not even try to call ip_sk_use_pmtu() on them. Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/ip.h | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/include/net/ip.h b/include/net/ip.h index 91a6b2c88341..aa7811993276 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -323,12 +323,15 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst, static inline unsigned int ip_skb_dst_mtu(const struct sk_buff *skb) { - if (!skb->sk || ip_sk_use_pmtu(skb->sk)) { + struct sock *sk = skb->sk; + + if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) { bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED; + return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding); - } else { - return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU); } + + return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU); } u32 ip_idents_reserve(u32 hash, int segs); -- 2.20.1