From patchwork Thu Jul 1 12:55:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12354085 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,USER_AGENT_GIT 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 8FFE1C11F64 for ; Thu, 1 Jul 2021 12:56:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B0D461402 for ; Thu, 1 Jul 2021 12:56:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236556AbhGAM6s (ORCPT ); Thu, 1 Jul 2021 08:58:48 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3339 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236536AbhGAM6o (ORCPT ); Thu, 1 Jul 2021 08:58:44 -0400 Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4GFycS0x6vz6L7Rq; Thu, 1 Jul 2021 20:45:44 +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; Thu, 1 Jul 2021 14:56:11 +0200 From: Roberto Sassu To: , CC: , , , , , , , , Roberto Sassu Subject: [PATCH v2 1/3] ima: Introduce ima_get_current_hash_algo() Date: Thu, 1 Jul 2021 14:55:50 +0200 Message-ID: <20210701125552.2958008-2-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210701125552.2958008-1-roberto.sassu@huawei.com> References: <20210701125552.2958008-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhreml749-chm.china.huawei.com (10.201.108.199) 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 Reviewed-by: Lakshmi Ramasubramanian --- 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,