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 54921C4167B for ; Tue, 14 Nov 2023 15:06:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233439AbjKNPGv (ORCPT ); Tue, 14 Nov 2023 10:06:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229504AbjKNPGs (ORCPT ); Tue, 14 Nov 2023 10:06:48 -0500 Received: from wp530.webpack.hosteurope.de (wp530.webpack.hosteurope.de [80.237.130.52]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B715310D for ; Tue, 14 Nov 2023 07:06:43 -0800 (PST) Received: from [2a02:8108:8980:2478:8cde:aa2c:f324:937e]; authenticated by wp530.webpack.hosteurope.de running ExIM with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) id 1r2uzv-0007D6-1O; Tue, 14 Nov 2023 16:06:39 +0100 Message-ID: Date: Tue, 14 Nov 2023 16:06:38 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: NULL pointer dereference regression when running `chmod -R root:tracing /sys/kernel/debug/tracing` Content-Language: en-US, de-DE To: Steven Rostedt Cc: Linux regressions mailing list , Milian Wolff , akaher@vmware.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, mark.rutland@arm.com, mhiramat@kernel.org References: <20231105160139.660634360@goodmis.org> <20231112104158.6638-1-milian.wolff@kdab.com> <2053f011-3c85-41e2-8685-1f46a2bc5fb8@leemhuis.info> <20231114085529.77099439@rorschach.local.home> From: Thorsten Leemhuis In-Reply-To: <20231114085529.77099439@rorschach.local.home> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-bounce-key: webpack.hosteurope.de;regressions@leemhuis.info;1699974404;bcf27ff2; X-HE-SMSGID: 1r2uzv-0007D6-1O Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14.11.23 14:55, Steven Rostedt wrote: > On Tue, 14 Nov 2023 14:38:57 +0100 > "Linux regression tracking #adding (Thorsten Leemhuis)" wrote: > >> [TLDR: I'm adding this report to the list of tracked Linux kernel >> regressions; the text you find below is based on a few templates >> paragraphs you might have encountered already in similar form. >> See link in footer if these mails annoy you.] >> >> On 12.11.23 11:41, Milian Wolff wrote: >>> >>> this patch seems to have introduced a kernel bug causing >>> a NULL pointer dereference when one runs: >>> >>> sudo chown -R root:tracing /sys/kernel/debug/tracing/ >>> >>> See the archlinux bug report I created initially for some more information: >>> https://bugs.archlinux.org/task/80230 >>> >>> With 6.6.1 and 9aaee3eebc91dd9ccebf6b6bc8a5f59d04ef718b reverted, >>> the above `chmod` command works. With a normal 6.6.1 build, or re-applying >>> the patch again, the command fails and `dmesg` shows: >> >> Steven is already working on this, but to ensure the issue doesn't fall >> through the cracks unnoticed, I'm adding it to regzbot, the Linux kernel >> regression tracking bot (and from the context I assume it happens in >> mainline as well) > > Note, the code in question was rewritten in 6.7 and the bug does not > exist there. It only exists in 6.6 and I already sent Greg the patch, > and he told me that it's in his queue. > > It's only a regression in 6.6 and not in mainline. Ahh, sorry fot getting this wrong and thx for letting me know. #regzbot introduced 9aaee3eebc91dd9ccebf6b6bc8a5f59d04ef718b #regzbot fix: eventfs: Check for NULL ef in eventfs_set_attr() Ciao, Thorsten P.S.: Enjoy LPC, hope to be there again next year.