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 8F247C433F5 for ; Tue, 5 Apr 2022 02:46:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230131AbiDECsU (ORCPT ); Mon, 4 Apr 2022 22:48:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230113AbiDECqH (ORCPT ); Mon, 4 Apr 2022 22:46:07 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C7303F7DC6 for ; Mon, 4 Apr 2022 18:51:26 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 8DF8260DF4 for ; Tue, 5 Apr 2022 01:51:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B523FC2BBE4; Tue, 5 Apr 2022 01:51:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1649123485; bh=FUZOU/Zn0+hZCBwK2e+4+p0g7CLULnGx2JfDvAvsADs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=IpU2thuQeNKvYD6CYRgqr/cFuvGZb+Tpddf2ICMSZSIViQJXCFZVasjVw4SdeRjtt 31SDzw45/X1ijxvol2oA981Bgm0i6wvclpyzHJJG+j3PZOdD7plY8fD2ffvO/H2cjW qXsjUWT/q4xsdAYI3mzSeGskOsTX8W8VwUnMLOgY= Date: Mon, 4 Apr 2022 18:51:23 -0700 From: Andrew Morton To: HORIGUCHI =?UTF-8?B?TkFPWUE=?= (=?UTF-8?B?5aCA5Y+j44CA55u05Lmf?=) Cc: Naoya Horiguchi , "linux-mm@kvack.org" , Mike Kravetz , Miaohe Lin , Yang Shi , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v6] mm/hwpoison: fix race between hugetlb free/demotion and memory_failure_hugetlb() Message-Id: <20220404185123.5be4389d99a0e4665a775da1@linux-foundation.org> In-Reply-To: <20220405014544.GA2583652@hori.linux.bs1.fc.nec.co.jp> References: <20220404092131.751733-1-naoya.horiguchi@linux.dev> <20220404115333.8cf80b9d3a7a55993ed60c57@linux-foundation.org> <20220405014544.GA2583652@hori.linux.bs1.fc.nec.co.jp> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 5 Apr 2022 01:45:45 +0000 HORIGUCHI NAOYA(堀口　直也) wrote: > On Mon, Apr 04, 2022 at 11:53:33AM -0700, Andrew Morton wrote: > > On Mon, 4 Apr 2022 18:21:31 +0900 Naoya Horiguchi wrote: > > > > > There is a race condition between memory_failure_hugetlb() and hugetlb > > > free/demotion, which causes setting PageHWPoison flag on the wrong page. > > > The one simple result is that wrong processes can be killed, but another > > > (more serious) one is that the actual error is left unhandled, so no one > > > prevents later access to it, and that might lead to more serious results > > > like consuming corrupted data. > > > > Should this fix be backported into stable kernels? > > This is a bug fix, so eligible to send to stable. But I thought that this > patch is larger than 100 lines (and hard to separeter to finer patches), > which seems to violate the rule stated in > Documentation/process/stable-kernel-rules.rst. > > But actually this rule might not be strictly applied (some patches in > v5.16.y do have more than 100 lines diff...). So if we can ignore this rule > exceptionally, that's OK and I'll add CC to stable again. I never actually knew about that rule ;) Thanks, I added the cc:stable. > The target commit of Fixed: tag is 761ad8d7c7b5 ("mm: hwpoison: introduce > memory_failure_hugetlb()") which was introduced in 4.13, so most of active > stable trees are affected. Oh. That's good to know. The original patch didn't have a Fixes: line. I added that as well.