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=-24.8 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,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1,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 2A61AC4167B for ; Fri, 11 Dec 2020 03:29:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCBDE23118 for ; Fri, 11 Dec 2020 03:29:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392583AbgLKD3M (ORCPT ); Thu, 10 Dec 2020 22:29:12 -0500 Received: from linux.microsoft.com ([13.77.154.182]:40434 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2395096AbgLKD26 (ORCPT ); Thu, 10 Dec 2020 22:28:58 -0500 Received: from [192.168.86.31] (c-71-197-163-6.hsd1.wa.comcast.net [71.197.163.6]) by linux.microsoft.com (Postfix) with ESMTPSA id 8633220B717A; Thu, 10 Dec 2020 19:28:16 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 8633220B717A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1607657297; bh=QfKvD7nczC7dNulMBg6BKzGgSG3r+S/OeqbB6AeHj8A=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=NumacvLNkph46dhWqG0xW5nAxs7cvMaftjS5/58D7e1N+gSf7uQlzYpesM1yw8imS /ZGpXcDYi3EqXw7QikDtZ6l4JoRRbRQU3lXLvXTMdwVCKtzqGIRJn6XYQ2g/tE9gZn oDAknC34ljJ5Z5zy6zfZH7Tx7E+7z+EDDiSauYXg= Subject: Re: [PATCH v7 4/8] IMA: add policy rule to measure critical data To: Tyler Hicks 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 References: <20201209194212.5131-1-tusharsu@linux.microsoft.com> <20201209194212.5131-5-tusharsu@linux.microsoft.com> <20201210231045.GI489768@sequoia> From: Tushar Sugandhi Message-ID: <472dc503-295c-1723-b329-c9e08fff4574@linux.microsoft.com> Date: Thu, 10 Dec 2020 19:28:15 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201210231045.GI489768@sequoia> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: On 2020-12-10 3:10 p.m., Tyler Hicks wrote: > 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. > Ok I will move IMA_DATA_SOURCE to 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. > Yup. Will do. >> + 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. > Will do. ~Tushar > Tyler > >> + return false; >> + >> + if (ima_rule_contains_lsm_cond(entry)) >> + return false; >> + >> break; >> default: >> return false; >> -- >> 2.17.1 >>