From 67757c65a373b23f15b8e6a4f771fc09d6d521b0 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 20 Mar 2020 16:52:02 +0100 Subject: [PATCH] tcp: also NULL skb->dev when copy was needed [ Upstream commit 07f8e4d0fddbf2f87e4cefb551278abc38db8cdd ] In rare cases retransmit logic will make a full skb copy, which will not trigger the zeroing added in recent change b738a185beaa ("tcp: ensure skb->dev is NULL before leaving TCP stack"). Cc: Eric Dumazet Fixes: 75c119afe14f ("tcp: implement rb-tree based retransmit queue") Fixes: 28f8bfd1ac94 ("netfilter: Support iif matches in POSTROUTING") Signed-off-by: Florian Westphal Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_output.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index b62b59b18db9..74d32739eaaa 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2976,8 +2976,12 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) tcp_skb_tsorted_save(skb) { nskb = __pskb_copy(skb, MAX_TCP_HEADER, GFP_ATOMIC); - err = nskb ? tcp_transmit_skb(sk, nskb, 0, GFP_ATOMIC) : - -ENOBUFS; + if (nskb) { + nskb->dev = NULL; + err = tcp_transmit_skb(sk, nskb, 0, GFP_ATOMIC); + } else { + err = -ENOBUFS; + } } tcp_skb_tsorted_restore(skb); if (!err) { -- 2.43.0