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 3CDFEC433F5 for ; Wed, 16 Mar 2022 14:15:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243294AbiCPOQb (ORCPT ); Wed, 16 Mar 2022 10:16:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35922 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356460AbiCPOQ3 (ORCPT ); Wed, 16 Mar 2022 10:16:29 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 128192F03D for ; Wed, 16 Mar 2022 07:15:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 7019FCE1F59 for ; Wed, 16 Mar 2022 14:14:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 078FAC340EC; Wed, 16 Mar 2022 14:14:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647440096; bh=UOyotBB63YnJSGCpSruZhKgJ1yBjSbgWDMnVUNRaOIM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SSE5EtL0mwgVRXonLOOzHuX2VHXREHp5X5OPTe8mNQtUXiMNEh54g1Ti+XMvneRi6 UY6Ip8esecZ6WSWyeB0vtSIjfkt5PeiJeZTzMNJK2kyCcjW+x4yriv9snpuMnHV5TW 2LsJinY41oybtGWlUJA9GYoBRYeZj9bx1OxTwjgw= Date: Wed, 16 Mar 2022 15:14:53 +0100 From: Greg KH To: Niklas Cassel Cc: Christoph Hellwig , "stable@vger.kernel.org" , "kbusch@kernel.org" , "martin.petersen@oracle.com" Subject: Re: kintegrityd workqueue fix backported, but only to some LTS Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Mar 14, 2022 at 03:48:59PM +0000, Niklas Cassel wrote: > On Mon, Mar 14, 2022 at 02:54:50PM +0100, Greg KH wrote: > > On Mon, Mar 14, 2022 at 01:08:57PM +0000, Niklas Cassel wrote: > > > On Mon, Mar 14, 2022 at 01:28:38PM +0100, Greg KH wrote: > > > > On Mon, Mar 14, 2022 at 11:50:18AM +0000, Niklas Cassel wrote: > > > > > Hello Christoph, stable, > > > > > > > > > > I recently saw a crash caused by the kintegrityd workqueue that could only > > > > > be reproduced on older kernels. > > > > > A null pointer dereference in function bio_integrity_verify_fn. > > > > > > > > > > The fix in Linus's tree for this: > > > > > 3df49967f6f1 ("block: flush the integrity workqueue in blk_integrity_unregister") > > > > > was first merged in v5.15. > > > > > > > > > > The fix has been backported to v5.10 LTS branch in: > > > > > 1ef68b84bc11 ("block: flush the integrity workqueue in blk_integrity_unregister") > > > > > > > > > > The fix doesn't have a fixes tag, but from inspecting the code, > > > > > I don't understand why this was only backported to v5.10, AFAICT it should > > > > > at least have been backported to v5.4, v4.19 and v4.14 LTS as well. > > > > > > > > > > Original series: > > > > > https://lore.kernel.org/all/20210914070657.87677-3-hch@lst.de/ > > > > > > > > > > The blk_flush_integrity() call that actually fixes the crash should be > > > > > trivial to backport/add before clearing the flag and doing the memset. > > > > > > > > A backported patch series would be great to have, to show that you have > > > > tested that it works properly. > > > > > > Hello Greg, > > > > > > Unfortunately, I don't have access to the machine. I was only provided > > > a kernel crash dump to diagnose the crash. > > > > > > I guess I was hoping for someone more familiar with the integrity stuff > > > to backport it. Both patch 1 and 3 are unrelated to the NULL pointer crash, > > > and because of various refactoring, I'm not sure if patch 1 and 3 are even > > > applicable for older kernel versions. > > > > I do not know what patch 1 and 3 refer to here, sorry :( > > Sorry, I was referring to patch 1/3 and 3/3 in the series: > https://lore.kernel.org/all/20210914070657.87677-1-hch@lst.de/ > > Looking at it again, patch 1/2 and 2/2 are both required. > > Patch 3/3, I don't know, since the flag used to be in bdi, but is now in > request_queue. > > But even then, since this doesn't have a Fixes tag, I'm not sure how far > this has to be backported. Christoph, thoughts? > > I'm assuming that it was the machine learning scripts that backported it to > 5.10, but considering that I've seen a crash dump with this in 4.18, it > definitely should have been backported to 4.19+ (but probably even further > back). Please test and if it works for you, provide a backported series and I will be glad to consider it. thanks, greg k-h