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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 725CFC433F5 for ; Tue, 28 Sep 2021 13:40:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B98D6101E for ; Tue, 28 Sep 2021 13:40:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240977AbhI1Nme (ORCPT ); Tue, 28 Sep 2021 09:42:34 -0400 Received: from mail-0301.mail-europe.com ([188.165.51.139]:35151 "EHLO mail-0301.mail-europe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233878AbhI1Nmd (ORCPT ); Tue, 28 Sep 2021 09:42:33 -0400 Date: Tue, 28 Sep 2021 13:40:48 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.ch; s=protonmail; t=1632836451; bh=goGNKPNGpmWN8xZiI0ePSv9y7ZFexCM2xLmGM1nxKSo=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=kkfouFtRMK3aepi1qqNdSoc/a4kHsRDzBVqc9ihvD94R7RCZ+osnCZg7wGaYEvvuW ORn3wFkg6v73WaZBVs53kK46hVjYo/ddzcLZWxVkLIs0F4BKTMZ8C9avhtUyuWkBo9 oy52UHmUbliMKMtgqb8jCoqa20XdtsAXujDRXAOU= To: ebiederm@xmission.com From: Jordan Glover Cc: LKML , "linux-mm\\@kvack.org" , "legion\\@kernel.org" , "containers\\@lists.linux-foundation.org" , Yu Zhao Reply-To: Jordan Glover Subject: Re: linux 5.14.3: free_user_ns causes NULL pointer dereference Message-ID: In-Reply-To: <878rzw77i3.fsf@disp2133> References: <1M9_d6wrcu6rdPe1ON0_k0lOxJMyyot3KAb1gdyuwzDPC777XVUWPHoTCEVmcK3fYfgu7sIo3PSaLe9KulUdm4TWVuqlbKyYGxRAjsf_Cpk=@protonmail.ch> <87ee9pa6xw.fsf@disp2133> <878rzw77i3.fsf@disp2133> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, September 16th, 2021 at 5:30 PM, wrote= : > Jordan Glover Golden_Miller83@protonmail.ch writes: > > > On Wednesday, September 15th, 2021 at 10:42 PM, Jordan Glover Golden_Mi= ller83@protonmail.ch wrote: > > > > > I had about 2 containerized (flatpak/bubblewrap) apps (browser + musi= c player) running . I quickly closed them with intent to shutdown the syste= m but instead get the freeze and had to use magic sysrq to reboot. System l= ogs end with what I posted and before there is nothing suspicious. > > > > > > Maybe it's some random fluke. I'll reply if I hit it again. > > > > Heh, it jut happened again. This time closing firefox alone had such > > effect: > > Ok. It looks like he have a couple of folks seeing issues here. > I thought we had all of the issues sorted out for the release of v5.14, > but it looks like there is still some little bug left. > > If Alex doesn't beat me to it I will see if I can come up with a > debugging patch to make it easy to help track down where the reference > count is going wrong. It will be a little bit as my brain is mush at > the moment. > > Eric As the issue persist in 5.14.7 I would be very interested in such patch. For now the thing is mostly reproducible when I close several tabs in ff th= en close the browser in short period of time. When I close tabs then wait out a bit then close the browser it doesn't happen so I guess some interrupted cleanup triggers it. Jordan