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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B98CBC433F5 for ; Wed, 20 Oct 2021 12:00:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F2D761361 for ; Wed, 20 Oct 2021 12:00:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230135AbhJTMDK (ORCPT ); Wed, 20 Oct 2021 08:03:10 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:39474 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229548AbhJTMDK (ORCPT ); Wed, 20 Oct 2021 08:03:10 -0400 Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 19KBMh4i001140; Wed, 20 Oct 2021 08:00:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : subject : from : reply-to : to : cc : date : in-reply-to : references : content-type : mime-version : content-transfer-encoding; s=pp1; bh=2atfIvf5ixrkwBkxddiwe1JyhuUXA4C0o6cch/eYBP0=; b=i+wo5AXB739rhOsrv7fJJkPOW4K+qGHZx2ii3jp9u6G88MfrP6oVw8n17VdHs09AXVQ5 nIHH4uk73tFrFRk/eLVXVv7CMHekEAz/zWLPBzcGQGN/jpjkVS1NLxIz2i/HMjyZWtZr tcxWgJJDuBZ2XixYlug0I2JxKZv5pyn8cfa/bWhZZOBkEGZK0FNMcd9W65nxFbNg9Ibh 7RTD3e32kfLIORsI/qust+Fh5RDjTbA2GdZ6k+kwIQDihpBf3R1AmrSeElbPMYdQrWJu HYtXBiY0nAwcjrS/907/mD9wwX9+QofumBxZ3UJ05fpx7TWNTMyk1xY55mrhGXBdIQiG jg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3btj6f8qpf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Oct 2021 08:00:42 -0400 Received: from m0098394.ppops.net (m0098394.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 19KBOCY8007783; Wed, 20 Oct 2021 08:00:41 -0400 Received: from ppma02dal.us.ibm.com (a.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.10]) by mx0a-001b2d01.pphosted.com with ESMTP id 3btj6f8qmp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Oct 2021 08:00:41 -0400 Received: from pps.filterd (ppma02dal.us.ibm.com [127.0.0.1]) by ppma02dal.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 19KBxHGw027484; Wed, 20 Oct 2021 12:00:36 GMT Received: from b03cxnp08026.gho.boulder.ibm.com (b03cxnp08026.gho.boulder.ibm.com [9.17.130.18]) by ppma02dal.us.ibm.com with ESMTP id 3bqpcc5e9f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 Oct 2021 12:00:36 +0000 Received: from b03ledav004.gho.boulder.ibm.com (b03ledav004.gho.boulder.ibm.com [9.17.130.235]) by b03cxnp08026.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 19KC0Y0W36635064 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 20 Oct 2021 12:00:34 GMT Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E729678091; Wed, 20 Oct 2021 12:00:33 +0000 (GMT) Received: from b03ledav004.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E09CB7807B; Wed, 20 Oct 2021 12:00:29 +0000 (GMT) Received: from jarvis.int.hansenpartnership.com (unknown [9.211.92.132]) by b03ledav004.gho.boulder.ibm.com (Postfix) with ESMTP; Wed, 20 Oct 2021 12:00:29 +0000 (GMT) Message-ID: Subject: Re: [PATCH v4 1/3] efi/libstub: Copy confidential computing secret area From: James Bottomley Reply-To: jejb@linux.ibm.com To: Greg KH , Dov Murik Cc: linux-efi@vger.kernel.org, Borislav Petkov , Ashish Kalra , Brijesh Singh , Tom Lendacky , Ard Biesheuvel , James Morris , "Serge E. Hallyn" , Andi Kleen , Andrew Scull , Dave Hansen , "Dr. David Alan Gilbert" , Tobin Feldman-Fitzthum , Jim Cadden , Daniele Buono , linux-coco@lists.linux.dev, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 20 Oct 2021 08:00:28 -0400 In-Reply-To: References: <20211020061408.3447533-1-dovmurik@linux.ibm.com> <20211020061408.3447533-2-dovmurik@linux.ibm.com> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.34.4 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: fXfdxmVhmW-oHxGkZz5qlolZAwivX7I6 X-Proofpoint-GUID: EdATHeW8N-0HlDMOIkTMqEVygdiToCfx X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.182.1,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-10-20_04,2021-10-20_02,2020-04-07_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxscore=0 priorityscore=1501 suspectscore=0 spamscore=0 malwarescore=0 clxscore=1011 mlxlogscore=969 bulkscore=0 lowpriorityscore=0 impostorscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2109230001 definitions=main-2110200070 Precedence: bulk List-ID: On Wed, 2021-10-20 at 08:39 +0200, Greg KH wrote: > On Wed, Oct 20, 2021 at 06:14:06AM +0000, Dov Murik wrote: [...] > > + help > > + Copy memory reserved by EFI for Confidential Computing (coco) > > + injected secrets, if EFI exposes such a table entry. > > Why would you want to "copy" secret memory? > > This sounds really odd here, it sounds like you are opening up a > security hole. Are you sure this is the correct text that everyone > on the "COCO" group agrees with? The way this works is that EFI covers the secret area with a boot time handoff block, which means it gets destroyed as soon as ExitBootServices is called as a security measure ... if you do nothing the secret is shredded. This means you need to make a copy of it before that happens if there are secrets that need to live beyond the EFI boot stub. James