* [PATCH net] tcp: also NULL skb->dev when copy was needed
@ 2020-03-20 15:52 Florian Westphal
2020-03-20 17:14 ` Eric Dumazet
2020-03-21 2:37 ` David Miller
0 siblings, 2 replies; 3+ messages in thread
From: Florian Westphal @ 2020-03-20 15:52 UTC (permalink / raw)
To: netdev; +Cc: Florian Westphal, Eric Dumazet
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>
---
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 e8cf8fde3d37..2f45cde168c4 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3041,8 +3041,12 @@ 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) {
--
2.24.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH net] tcp: also NULL skb->dev when copy was needed
2020-03-20 15:52 [PATCH net] tcp: also NULL skb->dev when copy was needed Florian Westphal
@ 2020-03-20 17:14 ` Eric Dumazet
2020-03-21 2:37 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: Eric Dumazet @ 2020-03-20 17:14 UTC (permalink / raw)
To: Florian Westphal, netdev; +Cc: Eric Dumazet
On 3/20/20 8:52 AM, Florian Westphal wrote:
> 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>
> ---
Good catch, thanks Florian !
Signed-off-by: Eric Dumazet <edumazet@google.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH net] tcp: also NULL skb->dev when copy was needed
2020-03-20 15:52 [PATCH net] tcp: also NULL skb->dev when copy was needed Florian Westphal
2020-03-20 17:14 ` Eric Dumazet
@ 2020-03-21 2:37 ` David Miller
1 sibling, 0 replies; 3+ messages in thread
From: David Miller @ 2020-03-21 2:37 UTC (permalink / raw)
To: fw; +Cc: netdev, edumazet
From: Florian Westphal <fw@strlen.de>
Date: Fri, 20 Mar 2020 16:52:02 +0100
> 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>
Applied and queued up for -stable.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-03-21 2:37 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-03-20 15:52 [PATCH net] tcp: also NULL skb->dev when copy was needed Florian Westphal
2020-03-20 17:14 ` Eric Dumazet
2020-03-21 2:37 ` David Miller
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