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 X-Spam-Level: X-Spam-Status: No, score=-22.0 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,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, UNWANTED_LANGUAGE_BODY,USER_AGENT_SANE_1,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 6ABE0C63798 for ; Fri, 20 Nov 2020 23:34:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 30F1F24124 for ; Fri, 20 Nov 2020 23:34:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="VzXBAcAf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728557AbgKTXdp (ORCPT ); Fri, 20 Nov 2020 18:33:45 -0500 Received: from linux.microsoft.com ([13.77.154.182]:44502 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726255AbgKTXdm (ORCPT ); Fri, 20 Nov 2020 18:33:42 -0500 Received: from [192.168.0.104] (c-73-42-176-67.hsd1.wa.comcast.net [73.42.176.67]) by linux.microsoft.com (Postfix) with ESMTPSA id 89BC420B717A; Fri, 20 Nov 2020 15:33:41 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 89BC420B717A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1605915221; bh=zmpsSKY4r1FjWqHBJ/nPiw3LVnG+vNwkCnUTsFeLSRM=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=VzXBAcAfAz5Ayii51kKy40d0qTGct8L6HwgiTEnBqNwIDE99VdQSgw5O3QTe6/oGF YVbjddqbqrGxB13ZGH2jr4YTVbTRmMj0vj7IFXSHQBlEFomqRDvoAhy1O8EP/gtYxX EKtEfEIhW/YrDq6NxVjwIIkoO2lon0aagWOwdNJc= Subject: Re: [PATCH v6 7/8] IMA: add a built-in policy rule for critical data measurement To: Mimi Zohar , Tushar Sugandhi , 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, linux-integrity@vger.kernel.org, selinux@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com References: <20201119232611.30114-1-tusharsu@linux.microsoft.com> <20201119232611.30114-8-tusharsu@linux.microsoft.com> From: Lakshmi Ramasubramanian Message-ID: <58607cc2-2a20-03d7-9f38-9c3bebb1c494@linux.microsoft.com> Date: Fri, 20 Nov 2020 15:33:36 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/20/20 6:30 AM, Mimi Zohar wrote: Hi Mimi, > > On Thu, 2020-11-19 at 15:26 -0800, Tushar Sugandhi wrote: >> 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. > > Everything needing to be said seems to be included in the second > sentence. Does the first sentence add anything? "Define a new > critical data builtin policy" makes for a good Subject line. Agreed - will update. > >> >> Add critical data to built-in IMA rules if the kernel command line >> contains "ima_policy=critical_data". > > The boot command line parameters are defined in Documentation/admin- > guide/kernel-parameters.txt. Please update "ima_policy". Will do. > >> >> 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; > > Unlike ima_fail_unverifiable_sigs, ima_use_critical_data is only used > during __init. Please change "__ro_after_init" to "__initdata". (The > critical data policy itself is defined properly as __ro_after_init.) Will do. > >> 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(); >> } >> > thanks, -lakshmi