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=-3.9 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 5DEDAC10F14 for ; Sun, 14 Apr 2019 22:33:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2666C2084D for ; Sun, 14 Apr 2019 22:33:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nPVQlPQJ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726621AbfDNWdD (ORCPT ); Sun, 14 Apr 2019 18:33:03 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:36659 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725772AbfDNWdC (ORCPT ); Sun, 14 Apr 2019 18:33:02 -0400 Received: by mail-pf1-f194.google.com with SMTP id z5so7619244pfn.3 for ; Sun, 14 Apr 2019 15:33:02 -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=G4/Ed9yOTXzd7O+D+DhfzhVAFtm5Y5ZbO/gGOh05x+c=; b=nPVQlPQJ4bJT385BTM8Hjjs5jgREcIGCnNK+WCYHIl8OmozOCyw9x9cdYiclRSgHFV PNliMb8+LNauJXsXQzEJVaodNqGV3w3X0Tt0gjWTchsLlKVKoe9A+qIZyYuqXaLO738L xB/pugCMdxyel5u9UC1ytb1yGiBMkQRTtMLW+bjmFhucZFvwP75MMULLmNd75p6ODCs7 bS6+vNWHII+10g4g3D0+Tu7cYatvHWtswSLe/5f6XuZqqXtaAR7IQPbHA0La9b4czoPs tvUBAOkwfSGEMHnWDu+W4uDDn1id0mnMu1uNXoEmxFwAJeAmHT+NbHveU0XALeUDmxnF C9qA== 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=G4/Ed9yOTXzd7O+D+DhfzhVAFtm5Y5ZbO/gGOh05x+c=; b=J6TcKmeFW81ldKGJBTUcwxsyQBCPV9frGfQy85rucWDMbR+KYSSPD6UcKT9KZFPDXg s/x9g36F5a7gHfXpkJLSeDI1thKOvex2PHsX2x2WFoZT2r8qPSXA5gvBwD4RsimrDeO5 3pGcdBrM46DO9yIkEU9j45MBGSBB+piQIhShYkEFrXi2e1thCqzMn0YQVkNMvDy+bdeB ut7lUQ2kW1F9N9YR79DBQv8ycuW4nAQmJgpr3GIqImYEFixvb0J36qspDD29aQi8LhXm HKFSXW6zduvFfa1Ze8S3L0uUjSd0S/k878Rojxl7fUmillF10SePgNSXyinOLHIaraie FbAA== X-Gm-Message-State: APjAAAVr5753H6ZdNwp0KpTIvMRGZBz1XEqQZHO1CBGuEzTLI6/wVsWe DvLiYBNX7tsNODG2TuVRhBs= X-Google-Smtp-Source: APXvYqxjyzDX5LIlBY/Mz0MtQdxQqFNGzzIyJmd01jm3rhjCvMYv724LWba6+IF0aMLPAO4nv1RzWw== X-Received: by 2002:aa7:8c86:: with SMTP id p6mr72653957pfd.37.1555281181821; Sun, 14 Apr 2019 15:33:01 -0700 (PDT) Received: from [192.168.86.235] (c-73-241-150-70.hsd1.ca.comcast.net. [73.241.150.70]) by smtp.gmail.com with ESMTPSA id t13sm48839061pgo.14.2019.04.14.15.33.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 14 Apr 2019 15:33:00 -0700 (PDT) Subject: Re: [PATCH net] ipv4: ensure rcu_read_lock() in ipv4_link_failure() To: David Miller , edumazet@google.com Cc: netdev@vger.kernel.org, eric.dumazet@gmail.com, syzkaller@googlegroups.com, ssuryaextr@gmail.com References: <20190414003221.1802-1-edumazet@google.com> <20190414.134406.35027185008708421.davem@davemloft.net> From: Eric Dumazet Message-ID: Date: Sun, 14 Apr 2019 15:32:59 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190414.134406.35027185008708421.davem@davemloft.net> 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 04/14/2019 01:44 PM, David Miller wrote: > From: Eric Dumazet > Date: Sat, 13 Apr 2019 17:32:21 -0700 > >> fib_compute_spec_dst() needs to be called under rcu protection. >> >> syzbot reported : > ... >> Fixes: ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure") >> Signed-off-by: Eric Dumazet >> Reported-by: syzbot > > Applied, thanks Eric. > > Please take a look at the cipso_v4_error case. > I am not familiar of this code, but it looks like it runs from BH rx handler, with rcu_read_lock() asserted. The problem for ipv4_link_failure() is that it can be run from a timer handler, which does not generally hold rcu_read_lock().