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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C33F3C4363A for ; Wed, 28 Oct 2020 11:11:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 44F99246AE for ; Wed, 28 Oct 2020 11:11:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 44F99246AE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AFC486B005C; Wed, 28 Oct 2020 07:11:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AABDF6B0068; Wed, 28 Oct 2020 07:11:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9E92C6B006C; Wed, 28 Oct 2020 07:11:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0027.hostedemail.com [216.40.44.27]) by kanga.kvack.org (Postfix) with ESMTP id 719DE6B005C for ; Wed, 28 Oct 2020 07:11:22 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 13BAD181AEF10 for ; Wed, 28 Oct 2020 11:11:22 +0000 (UTC) X-FDA: 77421068004.19.scent91_4d0765d27284 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin19.hostedemail.com (Postfix) with ESMTP id E071C1AD1B4 for ; Wed, 28 Oct 2020 11:11:21 +0000 (UTC) X-HE-Tag: scent91_4d0765d27284 X-Filterd-Recvd-Size: 1701 Received: from gentwo.org (gentwo.org [3.19.106.255]) by imf38.hostedemail.com (Postfix) with ESMTP for ; Wed, 28 Oct 2020 11:11:21 +0000 (UTC) Received: by gentwo.org (Postfix, from userid 1002) id E4C6A3FCCF; Wed, 28 Oct 2020 11:11:20 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id E14743F7B6; Wed, 28 Oct 2020 11:11:20 +0000 (UTC) Date: Wed, 28 Oct 2020 11:11:20 +0000 (UTC) From: Christopher Lameter X-X-Sender: cl@www.lameter.com To: Laurent Dufour cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, nathanl@linux.ibm.com, cheloha@linux.ibm.com, mhocko@suse.com, Vlastimil Babka , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , stable@vger.kernel.org Subject: Re: [PATCH v2] mm/slub: fix panic in slab_alloc_node() In-Reply-To: <20201027190406.33283-1-ldufour@linux.ibm.com> Message-ID: References: <7ef64e75-2150-01a9-074d-a754348683b3@suse.cz> <20201027190406.33283-1-ldufour@linux.ibm.com> User-Agent: Alpine 2.22 (DEB 394 2020-01-19) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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, 27 Oct 2020, Laurent Dufour wrote: > The issue is that object is not NULL while page is NULL which is odd but > may happen if the cache flush happened after loading object but before > loading page. Thus checking for the page pointer is required too. Ok then lets revert commit 6159d0f5c03e? The situation may occur elsewhere too.