From patchwork Thu Nov 19 23:26:10 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11919155 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-23.4 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 464F3C6379F for ; Thu, 19 Nov 2020 23:26:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0C09222BA for ; Thu, 19 Nov 2020 23:26:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="qEZd7tyF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727153AbgKSX0i (ORCPT ); Thu, 19 Nov 2020 18:26:38 -0500 Received: from linux.microsoft.com ([13.77.154.182]:33002 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727070AbgKSX00 (ORCPT ); Thu, 19 Nov 2020 18:26:26 -0500 Received: from tusharsu-Ubuntu.lan (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id 94B1F20B8005; Thu, 19 Nov 2020 15:26:24 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 94B1F20B8005 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1605828385; bh=uk4x4LQiWntk6528VOlokJxBRGx63RfP1GrYurFa5OI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qEZd7tyFxy6Hzpyvftyyglq0YHDh6WKPkmyzcSyI4JZCdGKJ0J3/YPV6L2iMDYBWz 7DTsQuz9XNOb7JLLg74Q5ZVpqqnMCuhsgcNsvU4/oVtFX7OD4MYi250SWEXB7TuGJc QQ8BPP/Mb+wuewh7tm72NOYej0SpBDWctJcWzO2o= From: Tushar Sugandhi To: zohar@linux.ibm.com, stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.com Cc: tyhicks@linux.microsoft.com, sashal@kernel.org, jmorris@namei.org, nramas@linux.microsoft.com, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com Subject: [PATCH v6 7/8] IMA: add a built-in policy rule for critical data measurement Date: Thu, 19 Nov 2020 15:26:10 -0800 Message-Id: <20201119232611.30114-8-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201119232611.30114-1-tusharsu@linux.microsoft.com> References: <20201119232611.30114-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: From: Lakshmi Ramasubramanian The IMA hook to measure kernel critical data, namely ima_measure_critical_data(), could be called before a custom IMA policy is loaded. Define a new critical data builtin policy to allow measuring early kernel integrity critical data before a custom IMA policy is loaded. Add critical data to built-in IMA rules if the kernel command line contains "ima_policy=critical_data". Signed-off-by: Lakshmi Ramasubramanian --- security/integrity/ima/ima_policy.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index c9e52dab0638..119604a3efa0 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -206,6 +206,10 @@ static struct ima_rule_entry secure_boot_rules[] __ro_after_init = { .flags = IMA_FUNC | IMA_DIGSIG_REQUIRED}, }; +static struct ima_rule_entry critical_data_rules[] __ro_after_init = { + {.action = MEASURE, .func = CRITICAL_DATA, .flags = IMA_FUNC}, +}; + /* An array of architecture specific rules */ static struct ima_rule_entry *arch_policy_entry __ro_after_init; @@ -228,6 +232,7 @@ __setup("ima_tcb", default_measure_policy_setup); static bool ima_use_appraise_tcb __initdata; static bool ima_use_secure_boot __initdata; +static bool ima_use_critical_data __ro_after_init; static bool ima_fail_unverifiable_sigs __ro_after_init; static int __init policy_setup(char *str) { @@ -242,6 +247,8 @@ static int __init policy_setup(char *str) ima_use_appraise_tcb = true; else if (strcmp(p, "secure_boot") == 0) ima_use_secure_boot = true; + else if (strcmp(p, "critical_data") == 0) + ima_use_critical_data = true; else if (strcmp(p, "fail_securely") == 0) ima_fail_unverifiable_sigs = true; else @@ -875,6 +882,11 @@ void __init ima_init_policy(void) ARRAY_SIZE(default_appraise_rules), IMA_DEFAULT_POLICY); + if (ima_use_critical_data) + add_rules(critical_data_rules, + ARRAY_SIZE(critical_data_rules), + IMA_DEFAULT_POLICY); + ima_update_policy_flag(); }