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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 0623CC742A1 for ; Thu, 11 Jul 2019 18:50:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDA5E20872 for ; Thu, 11 Jul 2019 18:50:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Wo6Nlzav" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728828AbfGKSuU (ORCPT ); Thu, 11 Jul 2019 14:50:20 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:40726 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726116AbfGKSuT (ORCPT ); Thu, 11 Jul 2019 14:50:19 -0400 Received: by mail-wr1-f68.google.com with SMTP id r1so7381936wrl.7 for ; Thu, 11 Jul 2019 11:50:18 -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=/SB0a1l/Aowjdg+cudPBQ5+bZEefq2USfsenvU+GhBM=; b=Wo6NlzavGXDUTvwckOnQhz74D3ijT8kEimOPii38F0U7+L9DtrxpzFPJaplnuS6+kz AwtIG5iJK8D66yeRv/o1pJEtZAT1n6yxTRmhF3fffpy6vRzN6I5bQhe84HFNhSE2zLIm Sw/LPBOUu/uecGTNlbm5L85Fr1GYMaSdrrjeySG7FyM/7I7lEPNqvkAh5zryS5BMfgJh 9HlW/ToeCPh8ah4CHLCf5IQhV5QOvcErkjAGXZj8EfjLcvRYwspdP4v3SL6Sj/2+mW3w s7quDbL1JdoXSuvdTU5yRmJxqCLS1kS6k03n/UW2P7j+F1iiNWhJjxynanGBqjPo2I8h WlGw== 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=/SB0a1l/Aowjdg+cudPBQ5+bZEefq2USfsenvU+GhBM=; b=oSjdOK8YC6XY0h/tWXK+lQGG/0Y3yFz+rucrKZEmXs9qmbLcojmbUlavh91F43Omt0 6oe2tJo3w8kuzF+xw6nKWbbnpjQZImEt9+3JGDOaEstrh3BGhaTx9nK19BACBlTnVoGi TOdi6SZ/pyUG9JxGlrv7wtQ5GkZRDs1jHL2Pw6x5D/TBiZN3TMru7ZTEgm/0u2vWfvsh 1O0QHYeUkXVM1vpQfT8OA7RJ8J8enGKxCFRsHEIt94SiuvHUpDZ9QiNL6dfQKtU8zbPu U4K+ST89U/lPLlqE+O7KDtBTL0eqlo380u2QjZpEIL2EXDPBWmEXcrcTLs8Vpov+nYEP onmw== X-Gm-Message-State: APjAAAUYEHBz2tLLr6JDMucPMxzsh4LEtbm8tA7238vtL9bxGnUgCYjf R44Icqptw6n05oN2UkXmSds= X-Google-Smtp-Source: APXvYqwdr7CyF5+ycoWWTkkroUIfBWObKiX41G5aBltt37H++MhykaMFIKTNCINLKjP5lSXxOb0uxw== X-Received: by 2002:a5d:430c:: with SMTP id h12mr6645890wrq.163.1562871017537; Thu, 11 Jul 2019 11:50:17 -0700 (PDT) Received: from [192.168.8.147] (143.160.185.81.rev.sfr.net. [81.185.160.143]) by smtp.gmail.com with ESMTPSA id j33sm11071843wre.42.2019.07.11.11.50.14 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 11 Jul 2019 11:50:16 -0700 (PDT) Subject: Re: [PATCH net 2/4] tcp: tcp_fragment() should apply sane memory limits To: Michal Kubecek , netdev@vger.kernel.org Cc: Eric Dumazet , Christoph Paasch , "Prout, Andrew - LLSC - MITLL" , David Miller , Greg Kroah-Hartman , Jonathan Looney , Neal Cardwell , Tyler Hicks , Yuchung Cheng , Bruce Curtis , Jonathan Lemon , Dustin Marquess References: <20190617170354.37770-3-edumazet@google.com> <03cbcfdf-58a4-dbca-45b1-8b17f229fa1d@gmail.com> <63cd99ed3d0c440185ebec3ad12327fc@ll.mit.edu> <96791fd5-8d36-2e00-3fef-60b23bea05e5@gmail.com> <20190711182654.GG5700@unicorn.suse.cz> From: Eric Dumazet Message-ID: <45fbbb23-2a23-47d0-0965-46b726832792@gmail.com> Date: Thu, 11 Jul 2019 20:50:13 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: <20190711182654.GG5700@unicorn.suse.cz> 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 7/11/19 8:26 PM, Michal Kubecek wrote: > > I'm aware it's not a realistic test. It was written as quick and simple > check of the pre-4.19 patch, but it shows that even TLP may not get > through. Most of TLP probes send new data, not rtx. But yes, I get your point. SO_SNDBUF=15000 in your case is seriously wrong. Lets code a safety feature over SO_SNDBUF to not allow pathological small values, because I do not want to support a constrained TCP stack in 2019.