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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BBBAFC433EF for ; Fri, 1 Jul 2022 11:42:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235622AbiGALmm (ORCPT ); Fri, 1 Jul 2022 07:42:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231351AbiGALmk (ORCPT ); Fri, 1 Jul 2022 07:42:40 -0400 Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [IPv6:2a01:488:42:1000:50ed:8234::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E221823B3; Fri, 1 Jul 2022 04:42:32 -0700 (PDT) Received: from [2a02:8108:963f:de38:eca4:7d19:f9a2:22c5]; authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1o7F2b-0005HB-Ml; Fri, 01 Jul 2022 13:42:29 +0200 Message-ID: Date: Fri, 1 Jul 2022 13:42:29 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Content-Language: en-US To: regressions@lists.linux.dev, kajetan.puchalski@arm.com Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org References: From: Thorsten Leemhuis Subject: Re: [Regression] stress-ng udp-flood causes kernel panic on Ampere Altra #forregzbot In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1656675752;a7962714; X-HE-SMSGID: 1o7F2b-0005HB-Ml Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [TLDR: I'm adding this regression report to the list of tracked regressions; all text from me you find below is based on a few templates paragraphs you might have encountered already already in similar form.] TWIMC: this mail is primarily send for documentation purposes and for regzbot, my Linux kernel regression tracking bot. These mails usually contain '#forregzbot' in the subject, to make them easy to spot and filter. Hi, this is your Linux kernel regression tracker. On 01.07.22 13:11, Kajetan Puchalski wrote: > Hi, > > While running the udp-flood test from stress-ng on Ampere Altra (Mt. > Jade platform) I encountered a kernel panic caused by NULL pointer > dereference within nf_conntrack. > > The issue is present in the latest mainline (5.19-rc4), latest stable > (5.18.8), as well as multiple older stable versions. The last working > stable version I found was 5.15.40. > > Through bisecting I've traced the issue back to mainline commit > 719774377622bc4025d2a74f551b5dc2158c6c30 (netfilter: conntrack: convert to refcount_t api), > on kernels from before this commit the test runs fine. As far as I can tell, this commit was > included in stable with version 5.15.41, thus causing the regression > compared to 5.15.40. It was included in the mainline with version 5.16. FWIW, looks like it was merged for v5.17-rc1 $ git describe --contains --tags 719774377622bc4025 v5.17-rc1~170^2~24^2~19 > The issue is very consistently reproducible as well, running this > command resulted in the same kernel panic every time I tried it on > different kernels from after the change in question was merged. > > stress-ng --udp-flood 0 -t 1m --metrics-brief --perf > > The commit was not easily revertible so I can't say whether reverting it > on the latest mainline would fix the problem or not. > > [...] > > The distirbution is Ubuntu 20.04.3 LTS, the architecture is aarch64. > > Please let me know if I can provide any more details or try any more > tests. Thanks for the report. To be sure below issue doesn't fall through the cracks unnoticed, I'm adding it to regzbot, my Linux kernel regression tracking bot: #regzbot ^introduced 719774377622bc402 #regzbot title net: netfilter: stress-ng udp-flood causes kernel panic on Ampere Altra This isn't a regression? This issue or a fix for it are already discussed somewhere else? It was fixed already? You want to clarify when the regression started to happen? Or point out I got the title or something else totally wrong? Then just reply -- ideally with also telling regzbot about it, as explained here: https://linux-regtracking.leemhuis.info/tracked-regression/ Reminder for developers: When fixing the issue, add 'Link:' tags pointing to the report (the mail this one replies to), as explained for in the Linux kernel's documentation; above webpage explains why this is important for tracked regressions. Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) P.S.: As the Linux kernel's regression tracker I deal with a lot of reports and sometimes miss something important when writing mails like this. If that's the case here, don't hesitate to tell me in a public reply, it's in everyone's interest to set the public record straight.