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=-2.3 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 52200C4360C for ; Wed, 2 Oct 2019 22:21:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1EC5621848 for ; Wed, 2 Oct 2019 22:21:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hQlxsdBw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726924AbfJBWV4 (ORCPT ); Wed, 2 Oct 2019 18:21:56 -0400 Received: from mail-pf1-f196.google.com ([209.85.210.196]:35775 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725799AbfJBWVz (ORCPT ); Wed, 2 Oct 2019 18:21:55 -0400 Received: by mail-pf1-f196.google.com with SMTP id 205so409699pfw.2 for ; Wed, 02 Oct 2019 15:21:55 -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=cOP3b02NaXtSwyjyzUPLAZuhEYqEJoCTiGkKoJPVbdI=; b=hQlxsdBwHtMpuWdtHhRwc1SF7dUWA6fviSZKHGNu81vBAAJgEoSCihWBtq3SoR9f+c 0Ap9H3N9/Fe9vAY9gPhFa4A0FYAjOAtfugGwz39YtXAOE4MET0WP47i2xAs+tWS7uynl wygVnH9iD9Yf7pCsB8IHlkxCxXeAg8XEfM+SSpFVMxgoMHPbtkstm3Ju8PgI3epJVztw GF3X2BydG5OXAaflK2Q3tUi+HdoHK79bzoru40Q6JvQM3ipYyLX/uG82y9yzY0se5Sf9 CRPa/tlYge8exM77+t7ICLG6pqYzT9cR6VDMyMDVeO43EEPo6ZHafk2CD0Rrt46mVuaQ j6zQ== 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=cOP3b02NaXtSwyjyzUPLAZuhEYqEJoCTiGkKoJPVbdI=; b=cPeTZPN5OflRbjiW7ckvTf1d6On2tpMtut41pj1ZvGORXMmwNDf0WMfRx5DjUC6nfW FNKEyrvaBx0PWOte0G9IQRusjeuaF3JA57DTlYqWiKx35zlcH99jaHkbZsTNYwHmPB5h qDDBtt567cRHSOPEkrtqQpe+rC9Kbu3mMWPsuLT+1RUIagA0njnIwEtuL6leccrTOfMU qjO7X+bb5MIV6h5cU1jU5irQqDhaXpjr0XKJviU7XlsXmwHDxKMOC45x2uyvTftf574x i+ggy/tmnm8X0uvZNEZVI6L3HkgITHCGo9lLCXshf5igxQ/xz+EPobClzRsh51zSW0E4 E7KQ== X-Gm-Message-State: APjAAAU9SncK238wtmzN+2zgkAGkSfupku1mF+xOLIuPxLsySE1rOLgm 3ZUgc03HkaJofZ0RleJBKpc= X-Google-Smtp-Source: APXvYqxSOnvH0Yi9/mDv5GPynab9prbVz1mokk/xdUn35hwJO3aMwwJYym0FERf6OQpyjGfGSEpGRA== X-Received: by 2002:a63:c7:: with SMTP id 190mr5900634pga.186.1570054915020; Wed, 02 Oct 2019 15:21:55 -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 c11sm470808pfj.114.2019.10.02.15.21.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 02 Oct 2019 15:21:53 -0700 (PDT) Subject: Re: [PATCH net v2] ipv6: Handle race in addrconf_dad_work To: David Ahern , Eric Dumazet , David Ahern , davem@davemloft.net, jakub.kicinski@netronome.com Cc: netdev@vger.kernel.org, rajendra.dendukuri@broadcom.com References: <20191001032834.5330-1-dsahern@kernel.org> <1ab3e0d0-fb37-d367-fd5f-c6b3262b6583@gmail.com> <18c18892-3f1c-6eb8-abbb-00fd6c9c64d3@gmail.com> <146a2f8a-8ee9-65f3-1013-ef60a96aa27b@gmail.com> <8d13d82c-6a91-1434-f1af-a2f39ecadbfb@gmail.com> From: Eric Dumazet Message-ID: <3dc05826-4661-8a8e-0c15-1a711ec84d07@gmail.com> Date: Wed, 2 Oct 2019 15:21:52 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <8d13d82c-6a91-1434-f1af-a2f39ecadbfb@gmail.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 10/2/19 3:13 PM, David Ahern wrote: > On 10/2/19 3:23 PM, Eric Dumazet wrote: >> >> >> On 10/2/19 2:08 PM, Eric Dumazet wrote: >>> >>> >>> On 10/1/19 11:18 AM, Eric Dumazet wrote: >>>> >>>> >>>> On 9/30/19 8:28 PM, David Ahern wrote: >>>>> From: David Ahern >>>>> >>>>> Rajendra reported a kernel panic when a link was taken down: >>>>> >>>>> [ 6870.263084] BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8 >>>>> [ 6870.271856] IP: [] __ipv6_ifa_notify+0x154/0x290 >>>>> >>>>> >>>>> >>>> >>>> Reviewed-by: Eric Dumazet >>>> >>>> Thanks ! >>>> >>> >>> Apparently this patch causes problems. I yet have to make an analysis. > > Ugh. I presume syzbot? can you forward the stack trace? No syzbot this time, but complete lack of connectivity on some of my test hosts. Incoming IPv6 packets go to ip6_forward() (!!!) and are dropped there. There seems to be something missing. ifp->state stays at INET6_IFADDR_STATE_PREDAD instead of INET6_IFADDR_STATE_DAD