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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,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 C5249C433E9 for ; Wed, 10 Mar 2021 19:11:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 94B8464FAE for ; Wed, 10 Mar 2021 19:11:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233057AbhCJTLR (ORCPT ); Wed, 10 Mar 2021 14:11:17 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:41149 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229741AbhCJTKx (ORCPT ); Wed, 10 Mar 2021 14:10:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615403453; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=my3I/Vyc00Xzj/W/fB+4uCbRyz46ViZsY10XYMSRH38=; b=ALeeLXy7guQojS0MEV3wjYtUFUXHgAOpVz2uqPycJ9guRRHQU+n0cLWKO6e6KtNXeOiXh2 9ES9cfiS69hP+AzXQYcP1J4pAWpmFJeDF9IIG5IXNx9/cPudWKMWa+GwI7zQ3nsu7Acnvz hj444TFBWOVipvebHSZQ7g1qzML8G4Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-439-DUzzdPhzMyestMQGjlZj4Q-1; Wed, 10 Mar 2021 14:10:51 -0500 X-MC-Unique: DUzzdPhzMyestMQGjlZj4Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 901BC881D73; Wed, 10 Mar 2021 19:10:47 +0000 (UTC) Received: from [10.36.112.107] (ovpn-112-107.ams2.redhat.com [10.36.112.107]) by smtp.corp.redhat.com (Postfix) with ESMTP id BB60A5D9DB; Wed, 10 Mar 2021 19:10:43 +0000 (UTC) To: "Rafael J. Wysocki" Cc: George Kennedy , Robert Moore , Erik Kaneda , Rafael Wysocki , Len Brown , ACPI Devel Maling List , "open list:ACPI COMPONENT ARCHITECTURE (ACPICA)" , Linux Kernel Mailing List , Mike Rapoport , Konrad Rzeszutek Wilk , Dan Carpenter , Dhaval Giani , Andrew Morton , Vlastimil Babka , Oscar Salvador , Wei Yang , Pankaj Gupta , Michal Hocko References: <1614802160-29362-1-git-send-email-george.kennedy@oracle.com> <9c3bc1b2-bb8d-194d-6faf-e4d7d346dc9b@oracle.com> <1ae44491-4404-6873-4ee6-6cf58c1ae6fb@redhat.com> From: David Hildenbrand Organization: Red Hat GmbH Subject: Re: [PATCH 1/1] ACPI: fix acpi table use after free Message-ID: Date: Wed, 10 Mar 2021 20:10:42 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> Memory gets allocated and used in a different order, which seems to have >>> exposed (yet another) latent BUG. >> >> Well, you can call it that, or you can say that things worked under >> certain assumptions regarding the memory allocation order which are >> not met any more. >> >>> The same could be reproduced via zone shuffling with a little luck. >> >> But nobody does that in practice. >> Dan will most certainly object. And I don't know what makes you speak in absolute words here. >> This would be relatively straightforward to address if ACPICA was not >> involved in it, but unfortunately that's not the case. >> >> Changing this part of ACPICA is risky, because such changes may affect >> other OSes using it, so that requires some serious consideration. >> Alternatively, the previous memory allocation order in Linux could be >> restored. > > Of course, long-term this needs to be addressed in the ACPI > initialization code, because it clearly is not robust enough, but in > the meantime there's practical breakage observable in the field, so > what can be done about that? *joke* enable zone shuffling. No seriously, fix the latent BUG. What again is problematic about excluding these pages from the page allcoator, for example, via memblock_reserve()? @Mike? -- Thanks, David / dhildenb