From patchwork Fri Sep 4 09:23:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 11756367 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 25D52138E for ; Fri, 4 Sep 2020 09:27:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 162B120770 for ; Fri, 4 Sep 2020 09:27:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730064AbgIDJ1Z (ORCPT ); Fri, 4 Sep 2020 05:27:25 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:2757 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730044AbgIDJ1Y (ORCPT ); Fri, 4 Sep 2020 05:27:24 -0400 Received: from lhreml744-chm.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id D83F044A6B178DFA5CF1; Fri, 4 Sep 2020 10:27:22 +0100 (IST) Received: from fraeml714-chm.china.huawei.com (10.206.15.33) by lhreml744-chm.china.huawei.com (10.201.108.194) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1913.5; Fri, 4 Sep 2020 10:27:22 +0100 Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.160) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1913.5; Fri, 4 Sep 2020 11:27:21 +0200 From: Roberto Sassu To: , CC: , , , , Roberto Sassu , Subject: [PATCH v2 04/12] evm: Execute evm_inode_init_security() only when the HMAC key is loaded Date: Fri, 4 Sep 2020 11:23:31 +0200 Message-ID: <20200904092339.19598-5-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.27.GIT In-Reply-To: <20200904092339.19598-1-roberto.sassu@huawei.com> References: <20200904092339.19598-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.65.160] X-ClientProxiedBy: lhreml709-chm.china.huawei.com (10.201.108.58) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: evm_inode_init_security() requires the HMAC key to calculate the HMAC on initial xattrs provided by LSMs. Unfortunately, with the evm_key_loaded() check, the function continues even if the HMAC key is not loaded (evm_key_loaded() returns true also if EVM has been initialized only with a public key). If the HMAC key is not loaded, evm_inode_init_security() returns an error later when it calls evm_init_hmac(). Thus, this patch replaces the evm_key_loaded() check with a check of the EVM_INIT_HMAC flag in evm_initialized, so that evm_inode_init_security() returns 0 instead of an error. Cc: stable@vger.kernel.org # 4.5.x Fixes: 26ddabfe96b ("evm: enable EVM when X509 certificate is loaded") Signed-off-by: Roberto Sassu Reviewed-by: Mimi Zohar --- security/integrity/evm/evm_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index e4b47759ba1c..4e9f5e8b21d5 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -527,7 +527,8 @@ int evm_inode_init_security(struct inode *inode, struct evm_xattr *xattr_data; int rc; - if (!evm_key_loaded() || !evm_protected_xattr(lsm_xattr->name)) + if (!(evm_initialized & EVM_INIT_HMAC) || + !evm_protected_xattr(lsm_xattr->name)) return 0; xattr_data = kzalloc(sizeof(*xattr_data), GFP_NOFS);