From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751988AbeCHUGM (ORCPT ); Thu, 8 Mar 2018 15:06:12 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:44042 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750867AbeCHUGK (ORCPT ); Thu, 8 Mar 2018 15:06:10 -0500 Subject: Re: [PATCH] security: Fix IMA Kconfig for dependencies on ARM64 From: Mimi Zohar To: Jiandi An , James Bottomley , Jason Gunthorpe Cc: dmitry.kasatkin@gmail.com, jmorris@namei.org, serge@hallyn.com, linux-integrity@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, linux-ima-user@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 08 Mar 2018 15:06:01 -0500 In-Reply-To: <191cfd49-0c66-a5ef-3d2b-b6c4132aa294@codeaurora.org> References: <1520400386-17674-1-git-send-email-anjiandi@codeaurora.org> <20180307185132.GA30102@ziepe.ca> <1520448953.10396.565.camel@linux.vnet.ibm.com> <1520449719.5558.28.camel@HansenPartnership.com> <1520450495.10396.587.camel@linux.vnet.ibm.com> <1520451662.24314.5.camel@HansenPartnership.com> <1520461156.10396.654.camel@linux.vnet.ibm.com> <191cfd49-0c66-a5ef-3d2b-b6c4132aa294@codeaurora.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 18030820-0012-0000-0000-000005BA88F0 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18030820-0013-0000-0000-00001936AAAB Message-Id: <1520539561.3605.92.camel@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-03-08_11:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1803080220 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2018-03-08 at 12:42 -0600, Jiandi An wrote: > So from the discussion, I hear James suggests to overhaul the current > IMA driver to not do measurement (calling tpm_pcr_read(), etc) until > after initrd phase so TPM drivers can be built as modules. > > I hear Mimi insists TPM drivers should be built-in when IMA driver is > enabled and set to Y in Kconfig. > > Do we have a consensus on which way we should go? > > I'm no expert on IMA and its driver. James, will you be kind enough > to look into overhauling the IMA driver to not measure until after > initrd phase if that's the consensus on resolving this? IMA selecting the TPM forces the TPM to be builtin.  There's nothing keeping you from directly configuring the TPM driver as builtin. For remote attestation to validate the IMA measurement list against the PCRs, the existing "ima_tcb" and "ima_policy=tcb" builtin policies require the TPM to be builtin. Not building the TPM into the kernel will also affect EVM. I don't have a problem accepting your patch now; and if/when there is a real use case for building the TPM driver as a kernel module for use with IMA-measurement, accepting those changes then. Mimi