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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32B3AC2BB41 for ; Tue, 16 Aug 2022 08:27:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AF1756B0073; Tue, 16 Aug 2022 04:27:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A7A7A8D0002; Tue, 16 Aug 2022 04:27:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 91BC08D0001; Tue, 16 Aug 2022 04:27:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 7D4676B0073 for ; Tue, 16 Aug 2022 04:27:20 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 43483160622 for ; Tue, 16 Aug 2022 08:27:20 +0000 (UTC) X-FDA: 79804776240.04.AE962C3 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf30.hostedemail.com (Postfix) with ESMTP id A6F0780030 for ; Tue, 16 Aug 2022 08:27:19 +0000 (UTC) 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 ams.source.kernel.org (Postfix) with ESMTPS id E0D4EB815AB; Tue, 16 Aug 2022 08:27:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2F213C433D7; Tue, 16 Aug 2022 08:27:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660638436; bh=nd7XrfWW5VTyg8CmThVCU5gCXi7zDbey5kxwNLdc4iY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=v2CzO7q9yAZpDeAAYd+SubkFwrskEPUWhivezYekuhFXWRFLZ/LP/qsydSsdYeSj/ FDra6jnB9tXexpEd2rue2hm3mBQvJoV3VwzOLVgeFO28G+12S0bsaaSFfo7UJ+jo0e SFhERawMb8Vb3E5wSnBJpl8zI6jax1Bfv0yJ3vCE= Date: Tue, 16 Aug 2022 09:15:18 +0200 From: Greg KH To: mawupeng Cc: rppt@linux.vnet.ibm.com, hughd@google.com, aarcange@redhat.com, hannes@cmpxchg.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, wangkefeng.wang@huawei.com, willy@infradead.org Subject: Re: [PATCH stable 4.14,4.19 1/1] mm: Fix page counter mismatch in shmem_mfill_atomic_pte Message-ID: References: <20220802013251.3022141-1-mawupeng1@huawei.com> <09129cd3-7363-3079-bd57-dde9c73684f1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=v2CzO7q9; spf=pass (imf30.hostedemail.com: domain of gregkh@linuxfoundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1660638439; a=rsa-sha256; cv=none; b=khKYkvrKbQycqdo53HKth+hQID/Q3x+O88Y2otv89dIIg2HkcH1EtXvIO8l6lF2PaO/kLT FwJidA5s8lhPlQDpgBNa8YHQfUKAyg+Y+5S1KDZoOvYBZFFKTr0ZyQyZAN4ttnFp/3L08l Vrx9cpPGneTKp7BjWKUHNftb29mTAuU= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1660638439; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=P/6V1M/tFJwnzmNGg/Len7h80Bla6WqgZRwHCf7FAkk=; b=yD/c0KrN7gvZo/nwDetA87fK4lBFfSI1LKIx2sgpOZRSWalvEXEgLddpSJWhqerZcux6VR Nhw46qV95lNTTh0sROkIsmDOq7vRfRzBtE9Sqn6H4452ZIMWa4Ipx/f1qHP4/t5A0pFG2B H2GIcME1zr580D8wvbMtqr+o8ad/sG0= X-Stat-Signature: 76uhyd9pxtqs34uek4ioad4pguusqjfu X-Rspamd-Queue-Id: A6F0780030 X-Rspamd-Server: rspam08 Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linuxfoundation.org header.s=korg header.b=v2CzO7q9; spf=pass (imf30.hostedemail.com: domain of gregkh@linuxfoundation.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org; dmarc=pass (policy=none) header.from=linuxfoundation.org X-Rspam-User: X-HE-Tag: 1660638439-429996 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Aug 16, 2022 at 03:04:08PM +0800, mawupeng wrote: > > > On 2022/8/16 13:31, Greg KH wrote: > > On Tue, Aug 16, 2022 at 11:27:08AM +0800, mawupeng wrote: > >> Cc Greg > > > > Cc Greg for what? I have no context here at all as to what you want me > > to do.. > > We found a bug related to memory cgroup counter in stable 4.14/4.19. > shmem_mfill_atomic_pte() wrongly called mem_cgroup_cancel_charge() in "success" > path, it should mem_cgroup_uncharge() to dec memory counter instead. > mem_cgroup_cancel_charge() should only be used if this transaction is > unsuccessful and mem_cgroup_uncharge() is used to do this if this transaction > succeed. > > Commit 3fea5a499d57 ("mm: memcontrol: convert page cache to a new mem_cgroup_charge() API") > in v5.8-rc1 change is charge/uncharge/cancel logic so don't have this > problem. > > This counter will underflow to negative maximum value and trigger oom to kill all > process include sshd and leave system unaccessible. > > The reason cc you is that we want to merge this bugfix into stable 4.14/4.19. This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.