From patchwork Fri Aug 28 01:57:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tushar Sugandhi X-Patchwork-Id: 11742049 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DF00C13B1 for ; Fri, 28 Aug 2020 01:57:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C7DA520848 for ; Fri, 28 Aug 2020 01:57:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="jIwOfUjv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728356AbgH1B5X (ORCPT ); Thu, 27 Aug 2020 21:57:23 -0400 Received: from linux.microsoft.com ([13.77.154.182]:38468 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728335AbgH1B5U (ORCPT ); Thu, 27 Aug 2020 21:57:20 -0400 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 39B5820553ED; Thu, 27 Aug 2020 18:57:19 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 39B5820553ED DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1598579839; bh=kFumSg9D6IWrKowDRCuR6JaYkRpAKGrG3kd2UMi5yG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jIwOfUjvQXDXIMbP0VzJC16ORhjF/LMllEOYLfOMSnZnqc6XGKsLEaw8udDpMU8dN Pza7ffFGu1KYIZvITQ4jggbSl9W/OsUTNFMOrjlofkqOXk3o96hovIq4uFI4cfZHk+ CD61VH/PhTFB7JNgZAjeC5JE+HqVFpu978bUOJQA= 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 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 v3 4/6] IMA: add policy to measure critical data from kernel components Date: Thu, 27 Aug 2020 18:57:02 -0700 Message-Id: <20200828015704.6629-5-tusharsu@linux.microsoft.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200828015704.6629-1-tusharsu@linux.microsoft.com> References: <20200828015704.6629-1-tusharsu@linux.microsoft.com> Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: There would be several candidate kernel components suitable for IMA measurement. Not all of them would have support for IMA measurement. Also, system administrators may not want to measure data for all of them, even when they support IMA measurement. An IMA policy specific to various kernel components is needed to measure their respective critical data. Add a new IMA policy "critical_kernel_data_sources" to support measuring various critical kernel components. This policy would enable the system administrators to limit the measurement to the components, if the components support IMA measurement. Signed-off-by: Tushar Sugandhi --- Documentation/ABI/testing/ima_policy | 3 +++ security/integrity/ima/ima_policy.c | 29 +++++++++++++++++++++++++++- 2 files changed, 31 insertions(+), 1 deletion(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index cd572912c593..7ccdc1964e29 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -48,6 +48,9 @@ Description: template:= name of a defined IMA template type (eg, ima-ng). Only valid when action is "measure". pcr:= decimal value + critical_kernel_data_sources:= list of kernel + components (eg, selinux|apparmor|dm-crypt) that + contain data critical to the security of the kernel. default policy: # PROC_SUPER_MAGIC diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 8866e84d0062..c8a044705347 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -33,6 +33,7 @@ #define IMA_PCR 0x0100 #define IMA_FSNAME 0x0200 #define IMA_KEYRINGS 0x0400 +#define IMA_DATA_SOURCES 0x0800 #define UNKNOWN 0 #define MEASURE 0x0001 /* same as IMA_MEASURE */ @@ -84,6 +85,7 @@ 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_sources; /* Measure data from these sources */ struct ima_template_desc *template; }; @@ -911,7 +913,7 @@ 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_sources, Opt_err }; static const match_table_t policy_tokens = { @@ -948,6 +950,7 @@ static const match_table_t policy_tokens = { {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, {Opt_keyrings, "keyrings=%s"}, + {Opt_data_sources, "critical_kernel_data_sources=%s"}, {Opt_err, NULL} }; @@ -1312,6 +1315,24 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) entry->flags |= IMA_KEYRINGS; break; + case Opt_data_sources: + ima_log_string(ab, "critical_kernel_data_sources", + args[0].from); + + if (entry->data_sources) { + result = -EINVAL; + break; + } + + entry->data_sources = ima_alloc_rule_opt_list(args); + if (IS_ERR(entry->data_sources)) { + result = PTR_ERR(entry->data_sources); + entry->data_sources = NULL; + break; + } + + entry->flags |= IMA_DATA_SOURCES; + break; case Opt_fsuuid: ima_log_string(ab, "fsuuid", args[0].from); @@ -1692,6 +1713,12 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); } + if (entry->flags & IMA_DATA_SOURCES) { + seq_puts(m, "critical_kernel_data_sources="); + ima_show_rule_opt_list(m, entry->data_sources); + seq_puts(m, " "); + } + if (entry->flags & IMA_PCR) { snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr); seq_printf(m, pt(Opt_pcr), tbuf);