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=-5.1 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_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 D3790C43603 for ; Fri, 6 Dec 2019 03:50:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A400720707 for ; Fri, 6 Dec 2019 03:50:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nLyAtT5u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726259AbfLFDul (ORCPT ); Thu, 5 Dec 2019 22:50:41 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:38710 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726076AbfLFDul (ORCPT ); Thu, 5 Dec 2019 22:50:41 -0500 Received: by mail-pf1-f195.google.com with SMTP id x185so2629247pfc.5 for ; Thu, 05 Dec 2019 19:50:41 -0800 (PST) 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=uV+1XBD6BJSPspyjSaABwF1kONPP1IZSCF+Qrd/s9Ig=; b=nLyAtT5uG3U1yciG3ITt2Ptl15ulMiAL9IZo6uBq7pnU7OJRAK8m0r3ar/YDtqPI4a Yj+RrV3T+/6kWx8QJsXkCe8ERKazQnpoaGuM4+5Gy7nfTELUTPmk8zCTW/Eww6PVr8JI y7Bkn8axi6T60jLeB4yf8igJ/abEGYMxVvEhIe7QYsrl//spkkmMGVYsdDhEgEb7q28m NTk6R3UBJm41h/1FYG12JR59BF7r8Ke47K9VAcDm08W6gx6GdCt26mxdRGeO6/oSsa7E FkjWoCaw50IkCLWua+ClkIePaQsIcAacg57cKvAIM0gL1fzQIyEQAJJnQtJFTFTwP82Y Tshg== 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=uV+1XBD6BJSPspyjSaABwF1kONPP1IZSCF+Qrd/s9Ig=; b=r4FqUgcm3tPI1GO57YxeZE7wrCdGNa9X9vUAMHdg7mxSHCCQexuw57jmj61QnQFHVX qTDlofbX0ieaQRnFvnM9Ir8ll/3l0EAUayiFn4x8v4oLl9B88Ts/o2g3Sk/DbCNk2df+ 7fgZMqhboQrIkU3DWyjucDkTb9r5RyzwvcEIWk7ReSUUQA33rO/Thtoxv6oohDRtVRgC bv04pQ1tixIWrK4GfT8LEcoI12DFDElMI0pVwgp8M0cTL+jXE/LYdhLd7SVqd7Zo6RY7 Jp5zu1xyAX0e4hcmTxX1QtrAWE0NPaJI0MztY/p3Pqe+1dmjagNKj2mtSS5+NfhseACQ pVkg== X-Gm-Message-State: APjAAAWdtiiyy3MhtFWa3UWig4RzOxcJ75nGOBnOx5+5spYVNgCgQWzs 0ZklKFLxULKNBjO8lho9dqY= X-Google-Smtp-Source: APXvYqyMbE4qAhsKixh4pGFGj26OrtM7rWUjkcEY9+QKPw59xHmNFWghEBcTgyXzAoUnkb9S7reFhQ== X-Received: by 2002:a65:6842:: with SMTP id q2mr1216815pgt.345.1575604240967; Thu, 05 Dec 2019 19:50:40 -0800 (PST) Received: from [192.168.86.235] (c-73-241-150-58.hsd1.ca.comcast.net. [73.241.150.58]) by smtp.gmail.com with ESMTPSA id n12sm12459908pgb.32.2019.12.05.19.50.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 05 Dec 2019 19:50:40 -0800 (PST) Subject: Re: [PATCH net v3 3/3] tcp: Protect accesses to .ts_recent_stamp with {READ,WRITE}_ONCE() To: Guillaume Nault , David Miller , Jakub Kicinski Cc: netdev@vger.kernel.org, Eric Dumazet References: <6473f122f953f6b0bf350ace584a721d0ae02ef6.1575595670.git.gnault@redhat.com> From: Eric Dumazet Message-ID: <27c9579d-634d-99c9-689c-65e3f4a2b296@gmail.com> Date: Thu, 5 Dec 2019 19:50:39 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <6473f122f953f6b0bf350ace584a721d0ae02ef6.1575595670.git.gnault@redhat.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 12/5/19 5:50 PM, Guillaume Nault wrote: > Syncookies borrow the ->rx_opt.ts_recent_stamp field to store the > timestamp of the last synflood. Protect them with READ_ONCE() and > WRITE_ONCE() since reads and writes aren't serialised. > > Fixes: 264ea103a747 ("tcp: syncookies: extend validity range") > Signed-off-by: Guillaume Nault Signed-off-by: Eric Dumazet To be fair, bug was there before the patch mentioned in the Fixes: tag, but we probably do not care enough to backport this to very old kernels.