From patchwork Fri Dec 11 23:58:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11969789 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 12220C52D67 for ; Sat, 12 Dec 2020 01:01:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E527B23770 for ; Sat, 12 Dec 2020 01:01:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2437558AbgLKX7z (ORCPT ); Fri, 11 Dec 2020 18:59:55 -0500 Received: from linux.microsoft.com ([13.77.154.182]:54884 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2437541AbgLKX7m (ORCPT ); Fri, 11 Dec 2020 18:59:42 -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 E111820B718A; Fri, 11 Dec 2020 15:58:21 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com E111820B718A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607731102; bh=b/dW00r01ZpsVJiBaCQgT3WIzsGSZSZkBDeK7+9jjQI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HFSOA7/g+5gCv/83iJ8oX5HZB1QfENbskxk4cySL68rSziR9zZO8Riv6d9RKvVI9t +KOQzahiHErtmfJj+DIAi5DFUjapRg27Guw/svWzrxAp1/uQQva2tJrgGAb3G5WCd3 9aNc2SfoXD77ig5vYh11xugCCxcYdc+8TCrESkqs= 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 v8 5/8] IMA: limit critical data measurement based on a label Date: Fri, 11 Dec 2020 15:58:04 -0800 Message-Id: <20201211235807.30815-6-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201211235807.30815-1-tusharsu@linux.microsoft.com> References: <20201211235807.30815-1-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 | 30 ++++++++++++++++++++++++++-- 2 files changed, 30 insertions(+), 2 deletions(-) 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 07116ff35c25..fea996a9e26c 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -34,6 +34,7 @@ #define IMA_PCR 0x0100 #define IMA_FSNAME 0x0200 #define IMA_KEYRINGS 0x0400 +#define IMA_DATA_SOURCE 0x0800 #define UNKNOWN 0 #define MEASURE 0x0001 /* same as IMA_MEASURE */ @@ -930,7 +931,7 @@ 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 = { @@ -967,6 +968,7 @@ 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} }; @@ -1134,7 +1136,8 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) if (entry->action & ~(MEASURE | DONT_MEASURE)) return false; - if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR)) + if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR | + IMA_DATA_SOURCE)) return false; if (ima_rule_contains_lsm_cond(entry)) @@ -1344,6 +1347,23 @@ 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); @@ -1724,6 +1744,12 @@ 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);