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=-23.2 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_IN_DEF_DKIM_WL autolearn=ham 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 3E3FAC4361B for ; Sat, 12 Dec 2020 19:21:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07BDD22257 for ; Sat, 12 Dec 2020 19:21:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2501901AbgLLTVo (ORCPT ); Sat, 12 Dec 2020 14:21:44 -0500 Received: from linux.microsoft.com ([13.77.154.182]:60692 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2501900AbgLLTVe (ORCPT ); Sat, 12 Dec 2020 14:21:34 -0500 Received: from sequoia (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id D778E20B717B; Sat, 12 Dec 2020 11:20:51 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D778E20B717B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607800852; bh=k520jqRvnhL9cGLtydGCC1OmTqOmk5O0XC1t5lPSUzc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LUOSyFmyJ+2q2tJjExToQUHdz/1pApBtOWUezomQoRfyit2Ze13EwZDuGefJeXsPt cAxfFBjwbGPg17UU5iQmldztEuro9+3ckIPNAkK9PF3e27Iid6paQAZ29AinO9HJfp 6i7dLXhEwKcX3vWCBFl3Mzb/EVEBEXWh6t5qV/LY= Date: Sat, 12 Dec 2020 13:20:49 -0600 From: Tyler Hicks To: Tushar Sugandhi Cc: 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, 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: Re: [PATCH v9 5/8] IMA: limit critical data measurement based on a label Message-ID: <20201212192049.GJ4951@sequoia> References: <20201212180251.9943-1-tusharsu@linux.microsoft.com> <20201212180251.9943-6-tusharsu@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201212180251.9943-6-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On 2020-12-12 10:02:48, Tushar Sugandhi wrote: > 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 Reviewed-by: Tyler Hicks Tyler > --- > Documentation/ABI/testing/ima_policy | 2 ++ > security/integrity/ima/ima_policy.c | 37 +++++++++++++++++++++++++--- > 2 files changed, 36 insertions(+), 3 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 d45c2dbb6d45..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 */ > @@ -85,6 +86,7 @@ struct ima_rule_entry { > } lsm[MAX_LSM_RULES]; > char *fsname; > struct ima_rule_opt_list *keyrings; /* Measure keys added to these keyrings */ > + struct ima_rule_opt_list *data_source; /* Measure data from this source */ > struct ima_template_desc *template; > }; > > @@ -480,7 +482,11 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule, > opt_list = rule->keyrings; > break; > case CRITICAL_DATA: > - return true; > + if (!rule->data_source) > + return true; > + > + opt_list = rule->data_source; > + break; > default: > return false; > } > @@ -925,7 +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 = { > @@ -962,6 +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} > }; > > @@ -1129,7 +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)) > @@ -1339,6 +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); > > @@ -1719,6 +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); > -- > 2.17.1 >