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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6FBEFEB64D8 for ; Fri, 16 Jun 2023 16:45:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232001AbjFPQpZ (ORCPT ); Fri, 16 Jun 2023 12:45:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230327AbjFPQpY (ORCPT ); Fri, 16 Jun 2023 12:45:24 -0400 Received: from sender4-of-o50.zoho.com (sender4-of-o50.zoho.com [136.143.188.50]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 206092D5D; Fri, 16 Jun 2023 09:45:22 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1686933873; cv=none; d=zohomail.com; s=zohoarc; b=K2OqRJfe2GJeQkgK+NEfGjq73mCcLWdnFodkO4sXrmbaizIXLgu/HsyvpE4MNNgewC3PfqZc9YurYjtjUtpFwePrVKK/iuvjr6v+Juj5UNR0kZ+OyQzlYBclaXTR02bROnRL5QOsjEc3rULeLFL4rcL14f35RIjIQC0oQz/H5xg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1686933873; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:To; bh=YFf4KgEPbWL7mvIIGoCh2dt81HyAXm/q6dL8q62QUqM=; b=kb9ONZdR3/WmMIh5NKTpkxb+0Jep9fQsD3Bvuhu7PXPgr+bmFTj7c0BpiAI8u0q+/CqrM9xchX3nosSThjR4vxl6hK+jOAMdlblqBaxbEl5VXL7ZtKqLvI/hV4K5g/KJfyApi2Qc6j+gtX9i9BG2priSe99Pqii8Iz34p0k8YEw= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=apertussolutions.com; spf=pass smtp.mailfrom=dpsmith@apertussolutions.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1686933873; s=zoho; d=apertussolutions.com; i=dpsmith@apertussolutions.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:References:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=YFf4KgEPbWL7mvIIGoCh2dt81HyAXm/q6dL8q62QUqM=; b=Zmm4hQ+1IB3Tmr3ET8PdXzI6pVC5ayUXdkDP6CGRW1kSJ6DFF7YlFkZ79uWonUGq TAW8ZH1SzLEIAN52IyqhxVDi7IKcNCnpgsJYk+ciL7/T37ppygDLq0bCbIGxIQYa8FL 9koCYVDg8mzvMx2f1pm8JHdr/FiOBV9ex0qFx/YM= Received: from [10.10.1.133] (static-72-81-132-2.bltmmd.fios.verizon.net [72.81.132.2]) by mx.zohomail.com with SMTPS id 1686933870911516.0622407770464; Fri, 16 Jun 2023 09:44:30 -0700 (PDT) Message-ID: Date: Fri, 16 Jun 2023 12:44:27 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH v6 02/14] Documentation/x86: Secure Launch kernel documentation Content-Language: en-US To: Matthew Garrett , Ross Philipson Cc: linux-kernel@vger.kernel.org, x86@kernel.org, linux-integrity@vger.kernel.org, linux-doc@vger.kernel.org, linux-crypto@vger.kernel.org, iommu@lists.linux-foundation.org, kexec@lists.infradead.org, linux-efi@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, ardb@kernel.org, James.Bottomley@hansenpartnership.com, luto@amacapital.net, nivedita@alum.mit.edu, kanth.ghatraju@oracle.com, trenchboot-devel@googlegroups.com References: <20230504145023.835096-1-ross.philipson@oracle.com> <20230504145023.835096-3-ross.philipson@oracle.com> <20230512104753.GA14461@srcf.ucam.org> From: "Daniel P. Smith" In-Reply-To: <20230512104753.GA14461@srcf.ucam.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ZohoMailClient: External Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 5/12/23 06:47, Matthew Garrett wrote: > On Thu, May 04, 2023 at 02:50:11PM +0000, Ross Philipson wrote: >> +Secure Launch does not interoperate with KASLR. If possible, the MLE should be >> +built with KASLR disabled:: > > Why does Secure Launch not interoperate with KASLR? > > Re: IOMMUs Until the IOMMU driver comes online, memory is protected by the PMRs regions requested by the Preamble (pre-launch code) in accordance with Intel TXT specifications and configured by the ACM. The KASLR randomizer will run before the IOMMU driver is able to come online and ensure frames used by the kernel are protected as well as frames that a driver may registered in a BAR are not blocked. >> +It is recommended that no other command line options should be set to override >> +the defaults above. > > What happens if they are? Does doing so change the security posture of > the system? If so, will the measurements be different in a way that > demonstrates the system is in an insecure state? > In an early version of the patch series this was enforced when turning on Secure Launch, but concerns were raised over this approach and was asked to allow the user to be able to shoot themselves in the foot. Overriding these values could render either an insecure state and/or an unstable system.