From patchwork Wed Jun 30 14:16:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12352247 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 01910C11F6B for ; Wed, 30 Jun 2021 14:16:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF2696144C for ; Wed, 30 Jun 2021 14:16:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235088AbhF3OTV (ORCPT ); Wed, 30 Jun 2021 10:19:21 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3333 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234855AbhF3OTV (ORCPT ); Wed, 30 Jun 2021 10:19:21 -0400 Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GFNN74Strz6D8Vp; Wed, 30 Jun 2021 22:03:03 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 30 Jun 2021 16:16:50 +0200 From: Roberto Sassu To: , CC: , , , , , , , , Roberto Sassu Subject: [PATCH 1/3] ima: Introduce ima_get_current_hash_algo() Date: Wed, 30 Jun 2021 16:16:33 +0200 Message-ID: <20210630141635.2862222-2-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210630141635.2862222-1-roberto.sassu@huawei.com> References: <20210630141635.2862222-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhreml754-chm.china.huawei.com (10.201.108.204) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org This patch introduces the new function ima_get_current_hash_algo(), that callers in the other kernel subsystems might use to obtain the hash algorithm selected by IMA. Its primary use will be to determine which algorithm has been used to calculate the digest written by ima_measure_critical_data() to the location passed as a new parameter (in a subsequent patch). Since the hash algorithm does not change after the IMA setup phase, there is no risk of races (obtaining a digest calculated with a different algorithm than the one returned). Signed-off-by: Roberto Sassu --- include/linux/ima.h | 7 +++++++ security/integrity/ima/ima_main.c | 5 +++++ 2 files changed, 12 insertions(+) diff --git a/include/linux/ima.h b/include/linux/ima.h index 61d5723ec303..81e830d01ced 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -11,9 +11,11 @@ #include #include #include +#include struct linux_binprm; #ifdef CONFIG_IMA +extern enum hash_algo ima_get_current_hash_algo(void); extern int ima_bprm_check(struct linux_binprm *bprm); extern int ima_file_check(struct file *file, int mask); extern void ima_post_create_tmpfile(struct user_namespace *mnt_userns, @@ -64,6 +66,11 @@ static inline const char * const *arch_get_ima_policy(void) #endif #else +static inline enum hash_algo ima_get_current_hash_algo(void) +{ + return HASH_ALGO__LAST; +} + static inline int ima_bprm_check(struct linux_binprm *bprm) { return 0; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 287b90509006..8ef1fa357e0c 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -76,6 +76,11 @@ static int __init hash_setup(char *str) } __setup("ima_hash=", hash_setup); +enum hash_algo ima_get_current_hash_algo(void) +{ + return ima_hash_algo; +} + /* Prevent mmap'ing a file execute that is already mmap'ed write */ static int mmap_violation_check(enum ima_hooks func, struct file *file, char **pathbuf, const char **pathname,