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 <edumazet@google.com>
Fixes: 75c119afe14f ("tcp: implement rb-tree based retransmit queue")
Fixes: 28f8bfd1ac94 ("netfilter: Support iif matches in POSTROUTING")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 660b24f..196425f 100644 (file)
--- 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) {