From: Eric Dumazet <eric.dumazet@gmail.com>
To: Yuchung Cheng <ycheng@google.com>, davem@davemloft.net
Cc: netdev@vger.kernel.org, ncardwell@google.com
Subject: Re: [PATCH v2 net] tcp: fix retrans timestamp on passive Fast Open
Date: Mon, 13 May 2019 12:43:40 -0700 [thread overview]
Message-ID: <2670dea8-e00f-0fc7-14c2-44c8ccf5875e@gmail.com> (raw)
In-Reply-To: <20190513173205.212181-1-ycheng@google.com>
On 5/13/19 10:32 AM, Yuchung Cheng wrote:
> Commit c7d13c8faa74 ("tcp: properly track retry time on
> passive Fast Open") sets the start of SYNACK retransmission
> time on passive Fast Open in "retrans_stamp". However the
> timestamp is not reset upon the handshake has completed. As a
> result, future data packet retransmission may not update it in
> tcp_retransmit_skb(). This may lead to socket aborting earlier
> unexpectedly by retransmits_timed_out() since retrans_stamp remains
> the SYNACK rtx time.
>
> This bug only manifests on passive TFO sender that a) suffered
> SYNACK timeout and then b) stalls on very first loss recovery. Any
> successful loss recovery would reset the timestamp to avoid this
> issue.
>
> Fixes: c7d13c8faa74 ("tcp: properly track retry time on passive Fast Open")
> Signed-off-by: Yuchung Cheng <ycheng@google.com>
> Signed-off-by: Neal Cardwell <ncardwell@google.com>
> ---
Signed-off-by: Eric Dumazet <edumazet@google.com>
next prev parent reply other threads:[~2019-05-13 19:43 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-13 17:32 [PATCH v2 net] tcp: fix retrans timestamp on passive Fast Open Yuchung Cheng
2019-05-13 19:43 ` Eric Dumazet [this message]
2019-05-14 22:19 ` David Miller
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