From patchwork Wed Jul 15 15:48:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lakshmi Ramasubramanian X-Patchwork-Id: 11665851 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 C6B2B6C1 for ; Wed, 15 Jul 2020 15:49:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF5C120663 for ; Wed, 15 Jul 2020 15:49:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="EXbT+s3M" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726546AbgGOPs7 (ORCPT ); Wed, 15 Jul 2020 11:48:59 -0400 Received: from linux.microsoft.com ([13.77.154.182]:45890 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725798AbgGOPs7 (ORCPT ); Wed, 15 Jul 2020 11:48:59 -0400 Received: from localhost.localdomain (c-73-42-176-67.hsd1.wa.comcast.net [73.42.176.67]) by linux.microsoft.com (Postfix) with ESMTPSA id 8F42B20B4908; Wed, 15 Jul 2020 08:48:58 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8F42B20B4908 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1594828138; bh=C4/E8JNB5AGVSfylzYPa4jC34oZsHrstt0THO4s6tdI=; h=From:To:Cc:Subject:Date:From; b=EXbT+s3MH1MIceREsHn214EN/fXoE9b9txDuAbUOZ+eQ5j9yjj8Ovt7t8e9t7VmEh cnhp3VdUEEGJipFdUyab7pifn//OZJXByv/h3LL6wgcciMo1fqx2HSoF7ZCW6s6ckm In6Ay/Uwu+/iYXsoUUUtzfHHX5k2PB8iPMOfPoBs= From: Lakshmi Ramasubramanian To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com Cc: jmorris@namei.org, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v1 0/5] LSM: Measure security module state Date: Wed, 15 Jul 2020 08:48:48 -0700 Message-Id: <20200715154853.23374-1-nramas@linux.microsoft.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Sender: selinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org Critical data structures of security modules are currently not measured. Therefore an attestation service, for instance, would not be able to attest whether the security modules are always operating with the policies and configuration that the system administrator had setup. The policies and configuration for the security modules could be tampered with by malware by exploiting Kernel vulnerabilities or modified through some inadvertent actions on the system. Measuring such critical data would enable an attestation service to better assess the state of the system. IMA subsystem measures system files, command line arguments passed to kexec, boot aggregate, keys, etc. It can be used to measure critical data structures of security modules as well. This change aims to address measuring critical data structures of security modules when they are initialized, when they are updated at runtime, and also periodically to detect any tampering. This change set is based off of Linux Kernel version 5.8-rc5. The following patch needs to be applied first before applying the patches in this patch set: https://patchwork.kernel.org/patch/11612989/ Change log: v1: => Per Stephen Smalley's suggestion added selinux_state booleans and hash of SELinux policy in the measured data for SELinux. => Call IMA hook from the security module directly instead of redirecting through the LSM. Lakshmi Ramasubramanian (5): IMA: Add LSM_STATE func to measure LSM data IMA: Define an IMA hook to measure LSM data LSM: Add security_state function pointer in lsm_info struct LSM: Define SELinux function to measure security state LSM: Define workqueue for measuring security module state Documentation/ABI/testing/ima_policy | 6 +- include/linux/ima.h | 4 + include/linux/lsm_hooks.h | 3 + security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_api.c | 2 +- security/integrity/ima/ima_main.c | 17 ++++ security/integrity/ima/ima_policy.c | 29 +++++-- security/security.c | 74 +++++++++++++++- security/selinux/Makefile | 2 + security/selinux/hooks.c | 2 + security/selinux/include/security.h | 19 +++++ security/selinux/measure.c | 122 +++++++++++++++++++++++++++ security/selinux/selinuxfs.c | 1 + security/selinux/ss/services.c | 23 ++++- 14 files changed, 293 insertions(+), 12 deletions(-) create mode 100644 security/selinux/measure.c