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 0C227C2D0E4 for ; Thu, 10 Dec 2020 23:12:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D540E23B85 for ; Thu, 10 Dec 2020 23:12:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733150AbgLJXLw (ORCPT ); Thu, 10 Dec 2020 18:11:52 -0500 Received: from linux.microsoft.com ([13.77.154.182]:35858 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389312AbgLJXL2 (ORCPT ); Thu, 10 Dec 2020 18:11:28 -0500 Received: from sequoia (162-237-133-238.lightspeed.rcsntx.sbcglobal.net [162.237.133.238]) by linux.microsoft.com (Postfix) with ESMTPSA id E447020B717A; Thu, 10 Dec 2020 15:10:46 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com E447020B717A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607641847; bh=HD/Eb/nvd1N3loreEli1aDjX1T/BFtunMTmkh4/ZF9I=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fJqTDE9woz58M75YJE5P6R/KI3RRTAP7jVY7xTi8OztwtzBfzPzXvA+FIWB3qCfoD T4B74zQam133lOOP/KcW6Gjxa2XXh6NNbRsrPJ9Y1ILKP1gQI8GhV2AW0pNsjH+liz jtDjvrlWBbrRUhFZFkag7FdlG/lb7hzANrZLme38= Date: Thu, 10 Dec 2020 17:10:45 -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 v7 4/8] IMA: add policy rule to measure critical data Message-ID: <20201210231045.GI489768@sequoia> References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> <20201209194212.5131-5-tusharsu@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201209194212.5131-5-tusharsu@linux.microsoft.com> Precedence: bulk List-ID: On 2020-12-09 11:42:08, 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 > --- > security/integrity/ima/ima_policy.c | 35 +++++++++++++++++++++++++---- > 1 file changed, 31 insertions(+), 4 deletions(-) > > diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c > index 2a0c0603626e..9a8ee80a3128 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 You introduce data_source= in the next patch. This macro shouldn't be added until the next patch. > > #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; > }; > > @@ -479,6 +481,12 @@ static bool ima_match_rule_data(struct ima_rule_entry *rule, > else > opt_list = rule->keyrings; > break; > + case CRITICAL_DATA: > + if (!rule->data_source) > + return true; > + else > + opt_list = rule->data_source; If you take my suggestions on patch #1, remove the else and simply assign opt_list here, too. > + break; > default: > break; > } > @@ -518,13 +526,19 @@ 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; > @@ -1119,6 +1133,19 @@ 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_DATA_SOURCE) || > + (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR | > + IMA_DATA_SOURCE))) IMA_DATA_SOURCE shouldn't exist in this patch. This isn't the right indentation, either. See how IMA_KEYRINGS is indented in the KEY_CHECK case above. Tyler > + return false; > + > + if (ima_rule_contains_lsm_cond(entry)) > + return false; > + > break; > default: > return false; > -- > 2.17.1 >