From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EB44924BD04 for ; Wed, 15 Oct 2025 20:31:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760560282; cv=none; b=edyXxA/tGNjEVwm9aV8F8tn6o/AeQIaNNM+C/Upys0rjYhwjwp1lq9pgIz3qugiyRwfvRFnnxWSrAMt8KKZpvYUAFeTBdfxzLQtslZ0CE58DneA4bRRAmE+w/H8fs0KlVPqmX3MlcWqVleb6kf86WWSpFuk2S5NzxFIWvmAeQ4M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760560282; c=relaxed/simple; bh=pivJSrMweKTt0+Bq5YHN9/KyBe29/QBMUSs/Cd5ZYiE=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=NCiclExIF18RvsUXsGUlXpjtYFVuumxE7YLxoHorT8eyEhurqybpheI2q5QFrwZf1Bd4LkiTKiFwqoPFvKBIq439MMli3Yphy9W+PFY8GlSflVlivExwyQ1f1QZVn4chyz++c66JKRmtpkosbxmXVoc7As4Lqm9fVwUhNlzs5Y8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Gcwq5vvm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Gcwq5vvm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36157C4CEF8; Wed, 15 Oct 2025 20:31:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760560281; bh=pivJSrMweKTt0+Bq5YHN9/KyBe29/QBMUSs/Cd5ZYiE=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Gcwq5vvmrJ6RdRh1hTdx5U1YcQblD+/6hWzWYTSue+LpOR7A9DaG9vlhmgi+3V1ac YHZvLBuwPcEFOgOnrADiyfSGFh8XAnc77LHwtMxqkf0Wz4Lxsdx9nzW+QIEjExCTxA kwYD9WpWMZhZarmuxOwRD/6w4GMNmldam4ccUWSNwUldcqSb+qx2rx93J53mEbjAsx 6ZsZMiJ1CS8ZSL+IiBtG+AH0gASOkj1QD/UCS5x48XHOBibewa+6LEfOQ3N0uWEloA Qtz2f/REM3XodoNxj2QwQLAOCyFgB2n62Ch7ebGmn3xFZa6d1SsTsqiCh9hvTs1dVf krzjoXsJaxo6Q== Date: Wed, 15 Oct 2025 13:31:20 -0700 From: Jakub Kicinski To: Cynthia , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich Cc: netdev@vger.kernel.org Subject: Re: [REGRESSION] in 6.17, failing __dev_change_net_namespace+0xb89/0xc30 Message-ID: <20251015133120.7ef53b20@kernel.org> In-Reply-To: <01070199e22de7f8-28f711ab-d3f1-46d9-b9a0-048ab05eb09b-000000@eu-central-1.amazonses.com> References: <01070199e22de7f8-28f711ab-d3f1-46d9-b9a0-048ab05eb09b-000000@eu-central-1.amazonses.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 14 Oct 2025 10:04:43 +0000 Cynthia wrote: > When I updated my machine to the newest kernel, a bug started to appear. > The system does not panic, but an error kept happening in dmesg. > > The bug happens with LXC/Incus when it tries to start a new container. > (but probably other things are affected too) > > > Steps to Reproduce: the bug can be reproduced in a libvirt VM, no need > for a specific system. Also I suspect the bug is also > architecture-independent, but I cannot verify that. > 1) Install ArchLinux (all dependencies are available). I was testing > with vanilla kernel, so any linux distro should be affected. > https://aur.archlinux.org/packages/linux-mainline can be installed, this > is the vanilla kernel with a generally good kernel config for most PCs. > 2) Install LXC/Incus (pacman -S incus) > 3) configure incus and start a container: > usermod -v 1000000-1000999999 -w 1000000-1000999999 root && > incus admin init && > incus launch images:debian/12 first # start a container > 4) Previous step should trigger incus to do namespaces. I'm not sure > what syscall is causing the bug, I do not have a mini C program. These > steps should be enough to see the log in the dmesg. > > I also did a git bisect, the first commit to have this bug is this: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0c17270f9b920e4e1777488f1911bbfdaf2af3be > > I initially reported this bug on Bugzilla, but after seeing 6 year old > bugs there, I'm not sure if that platform is still in use. > https://bugzilla.kernel.org/show_bug.cgi?id=220649 > > Since my initial report, 6.17.2 was released, the bug is still happening. > > I'm attaching 2 files: > dmesg_slice: the slice of dmesg containing the problematic frame (on a > bare-metal linux with AMD srso mitigation disabled) > bisect_log: a log of the git bisect process Thanks a lot for bisecting! Looking at the code my guess is that sysfs gives us ENOENT when we try to change owner of a file that isn't visible. Adding sysfs maintainers - should sysfs_group_attrs_change_owner() call is_visible before trying to touch the attr?