From patchwork Wed Dec 9 19:42:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11962329 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=-26.2 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,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 31C97C4167B for ; Wed, 9 Dec 2020 19:45:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1DCD23C8F for ; Wed, 9 Dec 2020 19:45:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387843AbgLITnt (ORCPT ); Wed, 9 Dec 2020 14:43:49 -0500 Received: from linux.microsoft.com ([13.77.154.182]:47630 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387839AbgLITnq (ORCPT ); Wed, 9 Dec 2020 14:43:46 -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 63C8420B718A; Wed, 9 Dec 2020 11:42:25 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 63C8420B718A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607542945; bh=bzuU81mo+/j5mNSRtkpRgP9nYoQTmrBcFrpkU3iE3ic=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pCjeKE1fNFwsNAHAmuZljsUTb383ZrRhoNT2NkT0DLtcfKkRLl/DmwpZWo9LvNPIS yXhMfNUvsjvhkquZbGZ4eZ05FX476WF4f4yVNY+GYbK5kFfuUtzAYYY0ALu5Ll5r4W TMEPWp4as7YNEEp0B2rXoAJ51EmwLmWFJ9yYRtjM= 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 v7 5/8] IMA: limit critical data measurement based on a label Date: Wed, 9 Dec 2020 11:42:09 -0800 Message-Id: <20201209194212.5131-6-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201209194212.5131-1-tusharsu@linux.microsoft.com> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: System administrators should be able to limit which kernel subsystems they want to measure the critical data for. To enable that, an IMA policy condition to choose specific kernel subsystems is needed. This policy condition would constrain the measurement of the critical data based on a label for the given subsystems. Add a new IMA policy condition - "data_source:=" to the IMA func CRITICAL_DATA to allow measurement of various kernel subsystems. This policy condition would enable the system administrators to restrict the measurement to the labels listed in "data_source:=". Limit the measurement to the labels that are specified in the IMA policy - CRITICAL_DATA+"data_source:=". If "data_sources:=" is not provided with the func CRITICAL_DATA, the data from all the supported kernel subsystems is measured. Signed-off-by: Tushar Sugandhi --- Documentation/ABI/testing/ima_policy | 2 ++ security/integrity/ima/ima_policy.c | 26 +++++++++++++++++++++++++- 2 files changed, 27 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 6ec7daa87cba..0f4ee9e0a455 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -52,6 +52,8 @@ Description: template:= name of a defined IMA template type (eg, ima-ng). Only valid when action is "measure". pcr:= decimal value + data_source:= [label] + label:= a unique string used for grouping and limiting critical data. default policy: # PROC_SUPER_MAGIC diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 9a8ee80a3128..7486d09a3f60 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -934,7 +934,7 @@ enum { Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt, Opt_appraise_type, Opt_appraise_flag, Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings, - Opt_err + Opt_data_source, Opt_err }; static const match_table_t policy_tokens = { @@ -971,6 +971,7 @@ static const match_table_t policy_tokens = { {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, {Opt_keyrings, "keyrings=%s"}, + {Opt_data_source, "data_source=%s"}, {Opt_err, NULL} }; @@ -1350,6 +1351,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->flags |= IMA_KEYRINGS; break; + case Opt_data_source: + ima_log_string(ab, "data_source", args[0].from); + + if (entry->data_source) { + result = -EINVAL; + break; + } + + entry->data_source = ima_alloc_rule_opt_list(args); + if (IS_ERR(entry->data_source)) { + result = PTR_ERR(entry->data_source); + entry->data_source = NULL; + break; + } + + entry->flags |= IMA_DATA_SOURCE; + break; case Opt_fsuuid: ima_log_string(ab, "fsuuid", args[0].from); @@ -1730,6 +1748,12 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); } + if (entry->flags & IMA_DATA_SOURCE) { + seq_puts(m, "data_source="); + ima_show_rule_opt_list(m, entry->data_source); + seq_puts(m, " "); + } + if (entry->flags & IMA_PCR) { snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr); seq_printf(m, pt(Opt_pcr), tbuf);