From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0CF3C04AA7 for ; Mon, 13 May 2019 19:43:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AD60220873 for ; Mon, 13 May 2019 19:43:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="DGSqO0LN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726982AbfEMTnn (ORCPT ); Mon, 13 May 2019 15:43:43 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:33181 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726098AbfEMTnn (ORCPT ); Mon, 13 May 2019 15:43:43 -0400 Received: by mail-pg1-f194.google.com with SMTP id h17so7309170pgv.0 for ; Mon, 13 May 2019 12:43:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=oQwn/J1Twm6bT/t2K0TcYDv5Z/LC49To9OHP7unRVAg=; b=DGSqO0LNcekXyIwJSaRJlpmgHZ9X/gP5TbZv+6kFOeSTo1iS/1EeWCJoeZKkyj1QV3 L75hMWvu4tbOhH/Xqpn3sQVTARIwrqwYSE0tpqvekCws/peDCEZZ+Ty5Q3Wm2Hx69Awt pil5L7c6PrnWbSn0i2w+QjpNhBymWGFQDLzyBwMQQT7SyQq3a/VdkKFR7c+WJlHS/lKO xHp30v+sYT7LpBzDW1z2jv7MrVocAPGgNXQGEEiQSb9rkt8tZcHeS97t6zwqmyCo/NiQ FI6H39pyCDbZRjYXcDhzKwiu9ssFVKbYbdqL3sktXa1rR/VU5+HIt8pHCVLvKZf6xCY4 64uQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=oQwn/J1Twm6bT/t2K0TcYDv5Z/LC49To9OHP7unRVAg=; b=bw0yiMvRByDxYSALhnLjHnrcPLdcD1D19M1QBK0IwW58ITCPjYTJIodXFXk2sX2TCG 4QIAt5E47Wk5pWFyG/T7vHkV6ot73zcqsCUFde21E6VXcPCXrmrL/17JyzpukvzQHyKa hxseOlZM/enEnRJubvg4DkwE+fZQek6XLvdunQ6y1Tam44FHm5MEc5qHrgushMHVU0vV buN4QpGzif1tc9t12XIxEspkZmhEJF9E8/sMkKnrOa/jrX49lb2hVeCXnRE3GazLh24D OmZmsjfoma4i/fpqBpsOyeDeSGg14YWVb26oL72i54PuUOnW2RJlmnMZDyJ8zFoAynlS xllQ== X-Gm-Message-State: APjAAAXUQP8RW3h2WkhPSmq69fTe0GfUGCE+/G5XMG9u0mytHrM/yq9y 75QQZShDtnOx2Hsn2LWUK+wF6Ibf X-Google-Smtp-Source: APXvYqzGubbIMnqZ52Baug9IRl/pq/HhU4lT2ThvLvU+vAdn9Uw9KS/2U95S7Om7g0rHXl0Kr8sQnw== X-Received: by 2002:aa7:8493:: with SMTP id u19mr35298009pfn.233.1557776622382; Mon, 13 May 2019 12:43:42 -0700 (PDT) Received: from ?IPv6:2620:15c:2c1:200:55c7:81e6:c7d8:94b? ([2620:15c:2c1:200:55c7:81e6:c7d8:94b]) by smtp.gmail.com with ESMTPSA id c189sm37433963pfg.46.2019.05.13.12.43.41 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Mon, 13 May 2019 12:43:41 -0700 (PDT) Subject: Re: [PATCH v2 net] tcp: fix retrans timestamp on passive Fast Open To: Yuchung Cheng , davem@davemloft.net Cc: netdev@vger.kernel.org, ncardwell@google.com References: <20190513173205.212181-1-ycheng@google.com> From: Eric Dumazet Message-ID: <2670dea8-e00f-0fc7-14c2-44c8ccf5875e@gmail.com> Date: Mon, 13 May 2019 12:43:40 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190513173205.212181-1-ycheng@google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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 > Signed-off-by: Neal Cardwell > --- Signed-off-by: Eric Dumazet