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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 B23E2C433DB for ; Thu, 18 Mar 2021 15:23:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8428E64EE2 for ; Thu, 18 Mar 2021 15:23:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230040AbhCRPXW (ORCPT ); Thu, 18 Mar 2021 11:23:22 -0400 Received: from mail-ot1-f48.google.com ([209.85.210.48]:43870 "EHLO mail-ot1-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229508AbhCRPWt (ORCPT ); Thu, 18 Mar 2021 11:22:49 -0400 Received: by mail-ot1-f48.google.com with SMTP id m21-20020a9d7ad50000b02901b83efc84a0so5524093otn.10; Thu, 18 Mar 2021 08:22:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=XY5+C+cwj/cp1ZOC1jOkEqcVS7X+FmIf75h5mCYb2HE=; b=Gi80fnLAHlU5O3XupvvxvRF97528Wzv8QE4J/yq0+PQTwIQ5CqE9/zZYUm8KnPE9Q6 3NkXpXQossWBHC0OAqDCM6iP7hmwrdEnza0Mt04316qIqXDpyVyWf5/8A/deN1PNLtYq fCbkUCkz+dm7ghV8eyZww7Q55b8tGD3MhjghmI0j3n9TjAmkqawQasrYbThexvoTKmrx 4JlilwfeTWjAJxC1voHoh/rFvAKbYgpZI3KRpysj+OVRlxgo4X7RYscyf+4e6HxKPDLk KcmtpNI8+S5IMnifhSIDVGj5qmP7pg/0MBHTkKCjD2VoyavJ6qZDwoVaNZtZGN/NsiAu CvyA== X-Gm-Message-State: AOAM530vpbiopHIKUG5p2zaSZxHrPIoUxAtDiCvmpEsEMSYzvjZUQnJQ zLRBGamC7TYbNfzYnRqmeBySVMVlVWYX4UYP4Ek= X-Google-Smtp-Source: ABdhPJx4Q32BHs/tMtlhyT+bXpmfN1I4SbzZsX3lnWmG6VWKbKxuXudNGvoEyuTQj8wMQ78FzsklmzfAqcCCRkXqelk= X-Received: by 2002:a05:6830:1e03:: with SMTP id s3mr8107660otr.321.1616080968401; Thu, 18 Mar 2021 08:22:48 -0700 (PDT) MIME-Version: 1.0 References: <3236337.DtqTXxM43S@kreacher> In-Reply-To: From: "Rafael J. Wysocki" Date: Thu, 18 Mar 2021 16:22:37 +0100 Message-ID: Subject: Re: [PATCH 1/1] ACPI: fix acpi table use after free To: Mike Rapoport Cc: "Rafael J. Wysocki" , Erik Kaneda , David Hildenbrand , George Kennedy , Robert Moore , Rafael Wysocki , Len Brown , ACPI Devel Maling List , "open list:ACPI COMPONENT ARCHITECTURE (ACPICA)" , Linux Kernel Mailing List , Konrad Rzeszutek Wilk , Dan Carpenter , Dhaval Giani , Andrew Morton , Vlastimil Babka , Oscar Salvador , Wei Yang , Pankaj Gupta , Michal Hocko Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Thu, Mar 18, 2021 at 11:50 AM Rafael J. Wysocki wrote: > > On Thu, Mar 18, 2021 at 8:25 AM Mike Rapoport wrote: > > > > On Wed, Mar 17, 2021 at 09:14:37PM +0100, Rafael J. Wysocki wrote: > > > On Monday, March 15, 2021 5:19:29 PM CET Rafael J. Wysocki wrote: > > > > On Sun, Mar 14, 2021 at 8:00 PM Mike Rapoport wrote: > > > > > > > > > > On Thu, Mar 11, 2021 at 04:36:31PM +0100, Rafael J. Wysocki wrote: > > > > > > On Wed, Mar 10, 2021 at 8:47 PM David Hildenbrand wrote: > > > > > > > > > > > > > > > > There is some care that should be taken to make sure we get the order > > > > > > > > right, but I don't see a fundamental issue here. > > > > > > > > > > > > Me neither. > > > > > > > > > > > > > > If I understand correctly, Rafael's concern is about changing the parts of > > > > > > > > ACPICA that should be OS agnostic, so I think we just need another place to > > > > > > > > call memblock_reserve() rather than acpi_tb_install_table_with_override(). > > > > > > > > > > > > Something like this. > > > > > > > > > > > > There is also the problem that memblock_reserve() needs to be called > > > > > > for all of the tables early enough, which will require some reordering > > > > > > of the early init code. > > > > > > > > > > > > > > Since the reservation should be done early in x86::setup_arch() (and > > > > > > > > probably in arm64::setup_arch()) we might just have a function that parses > > > > > > > > table headers and reserves them, similarly to how we parse the tables > > > > > > > > during KASLR setup. > > > > > > > > > > > > Right. > > > > > > > > > > I've looked at it a bit more and we do something like the patch below that > > > > > nearly duplicates acpi_tb_parse_root_table() which is not very nice. > > > > > > > > It looks to me that the code need not be duplicated (see below). > > > > > > > > > Besides, reserving ACPI tables early and then calling acpi_table_init() > > > > > (and acpi_tb_parse_root_table() again would mean doing the dance with > > > > > early_memremap() twice for no good reason. > > > > > > > > That'd be simply inefficient which is kind of acceptable to me to start with. > > > > > > > > And I changing the ACPICA code can be avoided at least initially, it > > > > by itself would be a good enough reason. > > > > > > > > > I believe the most effective way to deal with this would be to have a > > > > > function that does parsing, reservation and installs the tables supplied by > > > > > the firmware which can be called really early and then another function > > > > > that overrides tables if needed a some later point. > > > > > > > > I agree that this should be the direction to go into. > > > > > > So maybe something like the patch below? > > > > > > I'm not sure if acpi_boot_table_prepare() gets called early enough, though. > > > > To be 100% safe it should be called before e820__memblock_setup(). > > OK Well, that said, reserve_bios_regions() doesn't seem to have concerns like this and I'm not sure why ACPI tables should be reserved before this runs. That applies to efi_reserve_boot_services() too. I can put the new call before e820__memblock_alloc_reserved_mpc_new(), but I'm not sure why to put it before efi_reserve_boot_services(), say? From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: multipart/mixed; boundary="===============3268055426456954527==" MIME-Version: 1.0 From: Rafael J. Wysocki Subject: [Devel] Re: [PATCH 1/1] ACPI: fix acpi table use after free Date: Thu, 18 Mar 2021 16:22:37 +0100 Message-ID: In-Reply-To: CAJZ5v0g_y3X2Ps+ipBg702Q_RR3cm4gKBJoPqjazHXaisKGc4g@mail.gmail.com List-ID: To: devel@acpica.org --===============3268055426456954527== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable On Thu, Mar 18, 2021 at 11:50 AM Rafael J. Wysocki wr= ote: > > On Thu, Mar 18, 2021 at 8:25 AM Mike Rapoport wrot= e: > > > > On Wed, Mar 17, 2021 at 09:14:37PM +0100, Rafael J. Wysocki wrote: > > > On Monday, March 15, 2021 5:19:29 PM CET Rafael J. Wysocki wrote: > > > > On Sun, Mar 14, 2021 at 8:00 PM Mike Rapoport wrote: > > > > > > > > > > On Thu, Mar 11, 2021 at 04:36:31PM +0100, Rafael J. Wysocki wrote: > > > > > > On Wed, Mar 10, 2021 at 8:47 PM David Hildenbrand wrote: > > > > > > > > > > > > > > > > There is some care that should be taken to make sure we get= the order > > > > > > > > right, but I don't see a fundamental issue here. > > > > > > > > > > > > Me neither. > > > > > > > > > > > > > > If I understand correctly, Rafael's concern is about changi= ng the parts of > > > > > > > > ACPICA that should be OS agnostic, so I think we just need = another place to > > > > > > > > call memblock_reserve() rather than acpi_tb_install_table_w= ith_override(). > > > > > > > > > > > > Something like this. > > > > > > > > > > > > There is also the problem that memblock_reserve() needs to be c= alled > > > > > > for all of the tables early enough, which will require some reo= rdering > > > > > > of the early init code. > > > > > > > > > > > > > > Since the reservation should be done early in x86::setup_ar= ch() (and > > > > > > > > probably in arm64::setup_arch()) we might just have a funct= ion that parses > > > > > > > > table headers and reserves them, similarly to how we parse = the tables > > > > > > > > during KASLR setup. > > > > > > > > > > > > Right. > > > > > > > > > > I've looked at it a bit more and we do something like the patch b= elow that > > > > > nearly duplicates acpi_tb_parse_root_table() which is not very ni= ce. > > > > > > > > It looks to me that the code need not be duplicated (see below). > > > > > > > > > Besides, reserving ACPI tables early and then calling acpi_table_= init() > > > > > (and acpi_tb_parse_root_table() again would mean doing the dance = with > > > > > early_memremap() twice for no good reason. > > > > > > > > That'd be simply inefficient which is kind of acceptable to me to s= tart with. > > > > > > > > And I changing the ACPICA code can be avoided at least initially, it > > > > by itself would be a good enough reason. > > > > > > > > > I believe the most effective way to deal with this would be to ha= ve a > > > > > function that does parsing, reservation and installs the tables s= upplied by > > > > > the firmware which can be called really early and then another fu= nction > > > > > that overrides tables if needed a some later point. > > > > > > > > I agree that this should be the direction to go into. > > > > > > So maybe something like the patch below? > > > > > > I'm not sure if acpi_boot_table_prepare() gets called early enough, t= hough. > > > > To be 100% safe it should be called before e820__memblock_setup(). > > OK Well, that said, reserve_bios_regions() doesn't seem to have concerns like this and I'm not sure why ACPI tables should be reserved before this runs. That applies to efi_reserve_boot_services() too. I can put the new call before e820__memblock_alloc_reserved_mpc_new(), but I'm not sure why to put it before efi_reserve_boot_services(), say? --===============3268055426456954527==--