From patchwork Wed Apr 7 10:52:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12187817 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 874F5C43600 for ; Wed, 7 Apr 2021 10:53:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5E2B9613CE for ; Wed, 7 Apr 2021 10:53:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351613AbhDGKxX (ORCPT ); Wed, 7 Apr 2021 06:53:23 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2786 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351595AbhDGKxQ (ORCPT ); Wed, 7 Apr 2021 06:53:16 -0400 Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FFgwl3wVVz6815N; Wed, 7 Apr 2021 18:43:35 +0800 (CST) Received: from fraphisprd00473.huawei.com (7.182.8.141) 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 15.1.2106.2; Wed, 7 Apr 2021 12:53:05 +0200 From: Roberto Sassu To: , CC: , , , , Roberto Sassu Subject: [PATCH v5 02/12] evm: Load EVM key in ima_load_x509() to avoid appraisal Date: Wed, 7 Apr 2021 12:52:42 +0200 Message-ID: <20210407105252.30721-3-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210407105252.30721-1-roberto.sassu@huawei.com> References: <20210407105252.30721-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [7.182.8.141] X-ClientProxiedBy: lhreml753-chm.china.huawei.com (10.201.108.203) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org The public builtin keys do not need to be appraised by IMA as the restriction on the IMA/EVM trusted keyrings ensures that a key can be loaded only if it is signed with a key on the builtin or secondary keyrings. However, when evm_load_x509() is called, appraisal is already enabled and a valid IMA signature must be added to the EVM key to pass verification. Since the restriction is applied on both IMA and EVM trusted keyrings, it is safe to disable appraisal also when the EVM key is loaded. This patch calls evm_load_x509() inside ima_load_x509() if CONFIG_IMA_LOAD_X509 is enabled, which crosses the normal IMA and EVM boundary. Signed-off-by: Roberto Sassu Reviewed-by: Mimi Zohar --- security/integrity/iint.c | 4 +++- security/integrity/ima/ima_init.c | 4 ++++ 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 0ba01847e836..d66b94c7c8d5 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -208,7 +208,9 @@ int integrity_kernel_read(struct file *file, loff_t offset, void __init integrity_load_keys(void) { ima_load_x509(); - evm_load_x509(); + + if (!IS_ENABLED(CONFIG_IMA_LOAD_X509)) + evm_load_x509(); } static int __init integrity_fs_init(void) diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 6e8742916d1d..5076a7d9d23e 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -108,6 +108,10 @@ void __init ima_load_x509(void) ima_policy_flag &= ~unset_flags; integrity_load_x509(INTEGRITY_KEYRING_IMA, CONFIG_IMA_X509_PATH); + + /* load also EVM key to avoid appraisal */ + evm_load_x509(); + ima_policy_flag |= unset_flags; } #endif