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=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 48080C4361B for ; Sat, 12 Dec 2020 19:21:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 17D0622262 for ; Sat, 12 Dec 2020 19:21:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2501890AbgLLTVH (ORCPT ); Sat, 12 Dec 2020 14:21:07 -0500 Received: from linux.microsoft.com ([13.77.154.182]:60624 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2501886AbgLLTVH (ORCPT ); Sat, 12 Dec 2020 14:21:07 -0500 Received: from sequoia (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id E476820B717A; Sat, 12 Dec 2020 11:20:24 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com E476820B717A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607800825; bh=5ksj1UHNuBAABEl+/jn4cYgqXNXCmJX9vdNbEeENg08=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fBhBKQvHgJRUcQcgKM74P1aJ6cgivcillH1PmeggevYop5Ti3TGuGp+67Sewyn0tV NFaTeGUZsU30e8h422XiZeMfdr8ABKDyBOLHSK5/6YD9qc/mCpiiVjGWFuffIaTsOt pJpEPTSDysfNA86LdIPV0w0LX0cVc+sxn1vv28yw= Date: Sat, 12 Dec 2020 13:20:22 -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 4/8] IMA: add policy rule to measure critical data Message-ID: <20201212192022.GI4951@sequoia> References: <20201212180251.9943-1-tusharsu@linux.microsoft.com> <20201212180251.9943-5-tusharsu@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201212180251.9943-5-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On 2020-12-12 10:02:47, Tushar Sugandhi wrote: > A new IMA policy rule is needed for the IMA hook > ima_measure_critical_data() and the corresponding func CRITICAL_DATA for > measuring the input buffer. The policy rule should ensure the buffer > would get measured only when the policy rule allows the action. The > policy rule should also support the necessary constraints (flags etc.) > for integrity critical buffer data measurements. > > Add a policy rule to define the constraints for restricting integrity > critical data measurements. > > Signed-off-by: Tushar Sugandhi This looks nice. Thanks for the changes! Reviewed-by: Tyler Hicks Tyler > --- > Documentation/ABI/testing/ima_policy | 2 +- > security/integrity/ima/ima_policy.c | 29 ++++++++++++++++++++++++---- > 2 files changed, 26 insertions(+), 5 deletions(-) > > diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy > index e35263f97fc1..6ec7daa87cba 100644 > --- a/Documentation/ABI/testing/ima_policy > +++ b/Documentation/ABI/testing/ima_policy > @@ -32,7 +32,7 @@ Description: > func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK]MODULE_CHECK] > [FIRMWARE_CHECK] > [KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK] > - [KEXEC_CMDLINE] [KEY_CHECK] > + [KEXEC_CMDLINE] [KEY_CHECK] [CRITICAL_DATA] > mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND] > [[^]MAY_EXEC] > fsmagic:= hex value > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c > index a09d1a41a290..d45c2dbb6d45 100644 > --- a/security/integrity/ima/ima_policy.c > +++ b/security/integrity/ima/ima_policy.c > @@ -479,6 +479,8 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule, > > opt_list = rule->keyrings; > break; > + case CRITICAL_DATA: > + return true; > default: > return false; > } > @@ -515,13 +517,19 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, > { > int i; > > - if (func == KEY_CHECK) { > - return (rule->flags & IMA_FUNC) && (rule->func == func) && > - ima_match_rule_data(rule, func_data, cred); > - } > if ((rule->flags & IMA_FUNC) && > (rule->func != func && func != POST_SETATTR)) > return false; > + > + switch (func) { > + case KEY_CHECK: > + case CRITICAL_DATA: > + return ((rule->func == func) && > + ima_match_rule_data(rule, func_data, cred)); > + default: > + break; > + } > + > if ((rule->flags & IMA_MASK) && > (rule->mask != mask && func != POST_SETATTR)) > return false; > @@ -1116,6 +1124,17 @@ static bool ima_validate_rule(struct ima_rule_entry *entry) > if (ima_rule_contains_lsm_cond(entry)) > return false; > > + break; > + case CRITICAL_DATA: > + if (entry->action & ~(MEASURE | DONT_MEASURE)) > + return false; > + > + if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR)) > + return false; > + > + if (ima_rule_contains_lsm_cond(entry)) > + return false; > + > break; > default: > return false; > @@ -1248,6 +1267,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) > else if (IS_ENABLED(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) && > strcmp(args[0].from, "KEY_CHECK") == 0) > entry->func = KEY_CHECK; > + else if (strcmp(args[0].from, "CRITICAL_DATA") == 0) > + entry->func = CRITICAL_DATA; > else > result = -EINVAL; > if (!result) > -- > 2.17.1 >