From patchwork Fri Jun 26 15:58:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11627927 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 356A4912 for ; Fri, 26 Jun 2020 16:01:22 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0D6112053B for ; Fri, 26 Jun 2020 16:01:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="FOk4B8Z/"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="pMTRSoP0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0D6112053B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=VukDy4jS/zKoyu6UcclOdhjb3rXBoaojFhdyhvab8gc=; b=FOk4B8Z/FjVT7jycrB/cHnsIS 0JXOLFU3VFFEf0E9+JoA6m0Ot1DgTqjYmbnFF0VKQ3dL+D4ml3DZYwk42liywbtOU295YoqeZSPyN 8KwNz+TNiuVRNiUa7PWcjApRNSJ+mIVyAiDT/qKwc8mc7xE7bga0usNdhC3/PktvYTqDLgeOMZxYN 8I3mmRpRshBgccmEJtLXfc4J3qxQpd9Jc2VQ5M7ietbE2IHEp4OBkdc9jqsschFiIzdJsMecanrRL cIfNY0/t5bnZrhs6Wn5swTw9GlHWwtjigScTLOUWYVa0q8bFmNoUjI9q3ncQPH7ne8nO/tDIyS3Pk kR4hyh8Sg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1joqke-0006QP-HZ; Fri, 26 Jun 2020 15:58:52 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1joqkX-0006On-HQ for linux-arm-kernel@lists.infradead.org; Fri, 26 Jun 2020 15:58:47 +0000 Received: from dogfood.home (lfbn-nic-1-188-42.w2-15.abo.wanadoo.fr [2.15.37.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6B9D82080C; Fri, 26 Jun 2020 15:58:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593187125; bh=MI1bCIGMLcKccd2dmrayi3mwq6PLyLqFmsxPhzVVj+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pMTRSoP0LXtmeOSgiI76477HiCGpazaJWj4NOXf4jg37wdu7QJRO+hgH7/lbWlegp YbMVEvycZyfYFIw7lvXVRybyHe8zWKkHfI1tp0NnY6Ii7+0F1yeppV9UA9SqboJnmG d43IUvvLg9Bbk9CBd3EtE1y9ClPj/ONI/O8B3hsw= From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 2/2] arm64/acpi: disallow writeable AML opregion mapping for EFI code regions Date: Fri, 26 Jun 2020 17:58:32 +0200 Message-Id: <20200626155832.2323789-3-ardb@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200626155832.2323789-1-ardb@kernel.org> References: <20200626155832.2323789-1-ardb@kernel.org> MIME-Version: 1.0 X-Spam-Note: CRM114 invocation failed X-Spam-Score: -5.2 (-----) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-5.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: lorenzo.pieralisi@arm.com, kernel-hardening@lists.openwall.com, catalin.marinas@arm.com, linux-acpi@vger.kernel.org, sudeep.holla@arm.com, will@kernel.org, Ard Biesheuvel Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Given that the contents of EFI runtime code and data regions are provided by the firmware, as well as the DSDT, it is not unimaginable that AML code exists today that accesses EFI runtime code regions using a SystemMemory OpRegion. There is nothing fundamentally wrong with that, but since we take great care to ensure that executable code is never mapped writeable and executable at the same time, we should not permit AML to create writable mapping. Signed-off-by: Ard Biesheuvel --- arch/arm64/kernel/acpi.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 01b861e225b0..455966401102 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -301,6 +301,15 @@ void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys); return NULL; + case EFI_RUNTIME_SERVICES_CODE: + /* + * This would be unusual, but not problematic per se, + * as long as we take care not to create a writable + * mapping for executable code. + */ + prot = PAGE_KERNEL_RO; + break; + case EFI_ACPI_RECLAIM_MEMORY: /* * ACPI reclaim memory is used to pass firmware tables