Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756165AbdDERNV (ORCPT ); Wed, 5 Apr 2017 13:13:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56828 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756146AbdDERMr (ORCPT ); Wed, 5 Apr 2017 13:12:47 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A11B380F90 Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx03.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=dhowells@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com A11B380F90 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 19/24] acpi: Disable APEI error injection if the kernel is locked down From: David Howells To: linux-kernel@vger.kernel.org Cc: gnomes@lxorguk.ukuu.org.uk, linux-efi@vger.kernel.org, Linn Crosetto , matthew.garrett@nebula.com, gregkh@linuxfoundation.org, dhowells@redhat.com, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org Date: Wed, 05 Apr 2017 18:12:44 +0100 Message-ID: <149141236435.31282.18405211623757724751.stgit@warthog.procyon.org.uk> In-Reply-To: <149141219387.31282.6648284836568938717.stgit@warthog.procyon.org.uk> References: <149141219387.31282.6648284836568938717.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 05 Apr 2017 17:12:46 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1472 Lines: 38 From: Linn Crosetto ACPI provides an error injection mechanism, EINJ, for debugging and testing the ACPI Platform Error Interface (APEI) and other RAS features. If supported by the firmware, ACPI specification 5.0 and later provide for a way to specify a physical memory address to which to inject the error. Injecting errors through EINJ can produce errors which to the platform are indistinguishable from real hardware errors. This can have undesirable side-effects, such as causing the platform to mark hardware as needing replacement. While it does not provide a method to load unauthenticated privileged code, the effect of these errors may persist across reboots and affect trust in the underlying hardware, so disable error injection through EINJ if the kernel is locked down. Signed-off-by: Linn Crosetto Signed-off-by: David Howells --- drivers/acpi/apei/einj.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c index ec50c32ea3da..e082718d01c2 100644 --- a/drivers/acpi/apei/einj.c +++ b/drivers/acpi/apei/einj.c @@ -518,6 +518,9 @@ static int einj_error_inject(u32 type, u32 flags, u64 param1, u64 param2, int rc; u64 base_addr, size; + if (kernel_is_locked_down()) + return -EPERM; + /* If user manually set "flags", make sure it is legal */ if (flags && (flags & ~(SETWA_FLAGS_APICID|SETWA_FLAGS_MEM|SETWA_FLAGS_PCIE_SBDF)))