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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 80EC9C32751 for ; Wed, 31 Jul 2019 22:19:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 535BB206B8 for ; Wed, 31 Jul 2019 22:19:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KNtYwwW1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730265AbfGaWTK (ORCPT ); Wed, 31 Jul 2019 18:19:10 -0400 Received: from mail-vk1-f202.google.com ([209.85.221.202]:39858 "EHLO mail-vk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729694AbfGaWRI (ORCPT ); Wed, 31 Jul 2019 18:17:08 -0400 Received: by mail-vk1-f202.google.com with SMTP id d14so29968230vka.6 for ; Wed, 31 Jul 2019 15:17:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Tmn4zMTjEPlUC2x7KbFrZqCSBZYi0Bx5tDyyMiSTkHI=; b=KNtYwwW10pBzgMhIxkJCS/uENsLSdnfeR4Sv0jIZjE/kqgEDSSHm7qFmZbYcYGhoW6 ah/D6endKWnFZUJYaYj7c4Z+Ww90IGwhNDxIsN8ddpHHjZu1K7WMe4g+HC9ErAOL+Oan P+BwGpuxFHwb5gLspVTRu+6V+KSMYrvGqWk/8uA5Bh2vAksZ/MPON9EHcNcYaMbAc+XA C8a2S8I67YkszaV+R1icsFv0U0LpSf3kIpJXXD+cQD5wRZp78DzPMYAZY0V+NEYlQnJJ vgeuo4JK2gW0U5FN7kBmSeEw1cE/vN5M3uTg1hBFh/FZ4R94jpLxHeYydBoPJgYD3CRN TwlQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Tmn4zMTjEPlUC2x7KbFrZqCSBZYi0Bx5tDyyMiSTkHI=; b=QGajRbMZkHP3TrqDr/ssbXxMF1BRQ5BrZiETBn8ocuwr+vpr8MwHzypYbSuR0/HI95 mdZzFTc8B+dxz3FvRKaEKACP/7k3/+7NcB9mS9OgRdsAchTc961KfEuGdoHuOWtfLqWR +ub5QHVNSywZaZnTpuacSh/xHIFH/oDPKtS0aA1ciwlwtw8Lb5HkRVPNg29voLbUF5UT gAB8Di1I2pOIWvxC3wIaP5MmrtNiUczN5+I+5fc07iKASTojnVG5IcEGwtr5+eZwwHaS 4Leki/LFR7Zv7HPjtve8JvwdL5wrCkM16/1tQlJpdYG/QVd2Y+wfvG1RnA+1KMeoiKS+ ER5A== X-Gm-Message-State: APjAAAVfhifx1XRWFeeuNy1MDYgy824wBGdUX9t0CdMNrdbHgR0Owh3e vgWTHmEDcIebnpiuJ6FrrzXis1j2mQhGALM2qRb1rA== X-Google-Smtp-Source: APXvYqyn7wWBd2XqZE1SpADBue93B65mbiHUDF9eDEu3R6HN098MIwjsGaS2ZfwdCHJzwoGqIuAtZDoBJTZs2wCzIwTnOA== X-Received: by 2002:ab0:4307:: with SMTP id k7mr12696958uak.45.1564611426939; Wed, 31 Jul 2019 15:17:06 -0700 (PDT) Date: Wed, 31 Jul 2019 15:16:04 -0700 In-Reply-To: <20190731221617.234725-1-matthewgarrett@google.com> Message-Id: <20190731221617.234725-17-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190731221617.234725-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.22.0.770.g0f2c4a37fd-goog Subject: [PATCH V37 16/29] acpi: Disable ACPI table override if the kernel is locked down From: Matthew Garrett To: jmorris@namei.org Cc: linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Linn Crosetto , David Howells , Matthew Garrett , Kees Cook , linux-acpi@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Linn Crosetto >From the kernel documentation (initrd_table_override.txt): If the ACPI_INITRD_TABLE_OVERRIDE compile option is true, it is possible to override nearly any ACPI table provided by the BIOS with an instrumented, modified one. When lockdown is enabled, the kernel should disallow any unauthenticated changes to kernel space. ACPI tables contain code invoked by the kernel, so do not allow ACPI tables to be overridden if the kernel is locked down. Signed-off-by: Linn Crosetto Signed-off-by: David Howells Signed-off-by: Matthew Garrett Reviewed-by: Kees Cook cc: linux-acpi@vger.kernel.org --- drivers/acpi/tables.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index b32327759380..180ac4329763 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "internal.h" #ifdef CONFIG_ACPI_CUSTOM_DSDT @@ -578,6 +579,11 @@ void __init acpi_table_upgrade(void) if (table_nr == 0) return; + if (security_locked_down(LOCKDOWN_ACPI_TABLES)) { + pr_notice("kernel is locked down, ignoring table override\n"); + return; + } + acpi_tables_addr = memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS, all_tables_size, PAGE_SIZE); -- 2.22.0.770.g0f2c4a37fd-goog