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=-20.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 76527C433E0 for ; Tue, 9 Feb 2021 18:41:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2B0A964E40 for ; Tue, 9 Feb 2021 18:41:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233569AbhBISlB (ORCPT ); Tue, 9 Feb 2021 13:41:01 -0500 Received: from linux.microsoft.com ([13.77.154.182]:59232 "EHLO linux.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233463AbhBISfg (ORCPT ); Tue, 9 Feb 2021 13:35:36 -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 7089D2020E9E; Tue, 9 Feb 2021 10:31:44 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 7089D2020E9E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1612895504; bh=wGYdUbhWR5y9KoUnFO9IRu5Hqx5/3X+QjRRHMVd3EHI=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=bBpT7yfHfMpytdV83pn28BmzOiyTLc1T0B+pzDQ3hBh0YKIATeBHVdzevnaRWHOp/ 4LayizfSQ7VyW1d6V5S37JjCejSjQ3iyaz9oFGbNChIRMrz8ypKLiVYkU7rg7psdXs 8iHk8gRVIzPt36YlYxG/oGKbbj08xHP7pLqS6fl4= Subject: Re: [PATCH 3/3] IMA: add support to measure duplicate buffer for critical data hook To: Mimi Zohar , stephen.smalley.work@gmail.com, casey@schaufler-ca.com, agk@redhat.com, snitzer@redhat.com, gmazyland@gmail.com, paul@paul-moore.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 References: <20210130004519.25106-1-tusharsu@linux.microsoft.com> <20210130004519.25106-4-tusharsu@linux.microsoft.com> <158dc2d3398316edefbafdb1cfea5eca840a06e6.camel@linux.ibm.com> From: Tushar Sugandhi Message-ID: <8af5bf67-54d3-f358-6cb6-34733fc72df2@linux.microsoft.com> Date: Tue, 9 Feb 2021 10:31:43 -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: <158dc2d3398316edefbafdb1cfea5eca840a06e6.camel@linux.ibm.com> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: On 2021-02-08 12:24 p.m., Mimi Zohar wrote: > Hi Tushar, > > On Fri, 2021-01-29 at 16:45 -0800, Tushar Sugandhi wrote: > >> diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c >> >> index c096ef8945c7..fbf359495fa8 100644 >> --- a/security/integrity/ima/ima_queue.c >> +++ b/security/integrity/ima/ima_queue.c >> @@ -158,7 +158,7 @@ static int ima_pcr_extend(struct tpm_digest *digests_arg, int pcr) >> */ >> int ima_add_template_entry(struct ima_template_entry *entry, int violation, >> const char *op, struct inode *inode, >> - const unsigned char *filename) >> + const unsigned char *filename, bool allow_dup) >> { >> u8 *digest = entry->digests[ima_hash_algo_idx].digest; >> > struct tpm_digestate_entry(struct ima_template_entry *entry, int violation, Not sure I understand this. Maybe a typo? Could you please explain? >> >> mutex_lock(&ima_extend_list_mutex); >> if (!violation) { >> - if (ima_lookup_digest_entry(digest, entry->pcr)) { >> + if (!allow_dup && >> + ima_lookup_digest_entry(digest, entry->pcr)) { > > Can't this change be simplified to "if (!violation && !allow_dup)"? > Sure. Will do. Earlier I wasn't sure if 'violation' would touch any other use-cases inadvertently. That's why I localized the change as above. But now since we are supporting other scenarios as well, I believe "if (!violation && !allow_dup)" would be cleaner. > Also perhaps instead of passing another variable "allow_dup" to each of > these functions, pass a mask containing violation and allow_dup. > There were examples of both approaches in ima_match_policy(). - int *pcr/ima_template_desc **template_desc as an out-param; - and various actions as flags in return int. Earlier I couldn't decide one way or the other, so I picked the out-param approach. But since allow_dup is just a single bit info, returning it as a bit in the action flag is a cleaner solution. Will implement it with flag in the next iteration. Thanks again for reviewing the series. Really appreciate it. Thanks, Tushar >> audit_cause = "hash_exists"; >> result = -EEXIST; >> goto out; > > thanks, > > Mimi >