From patchwork Sun Nov 25 15:14:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nayna Jain X-Patchwork-Id: 10696893 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A9A3F5A4 for ; Sun, 25 Nov 2018 15:19:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9859029717 for ; Sun, 25 Nov 2018 15:19:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8C91329B1F; Sun, 25 Nov 2018 15:19:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 27B0629717 for ; Sun, 25 Nov 2018 15:19:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726918AbeKZCKi (ORCPT ); Sun, 25 Nov 2018 21:10:38 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:41092 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726877AbeKZCK0 (ORCPT ); Sun, 25 Nov 2018 21:10:26 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wAPFEXdF120021 for ; Sun, 25 Nov 2018 10:19:09 -0500 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2nymvtebx2-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Sun, 25 Nov 2018 10:19:09 -0500 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Sun, 25 Nov 2018 15:19:01 -0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps4075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wAPFJ0ah5898522 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Sun, 25 Nov 2018 15:19:00 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C78A24C046; Sun, 25 Nov 2018 15:19:00 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 393F04C040; Sun, 25 Nov 2018 15:18:57 +0000 (GMT) Received: from swastik.ibmuc.com (unknown [9.85.72.131]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Sun, 25 Nov 2018 15:18:56 +0000 (GMT) From: Nayna Jain To: linux-integrity@vger.kernel.org Cc: linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, zohar@linux.ibm.com, dhowells@redhat.com, jforbes@redhat.com, seth.forshee@canonical.com, kexec@lists.infradead.org, keyrings@vger.kernel.org, vgoyal@redhat.com, ebiederm@xmission.com, mpe@ellerman.id.au, Josh Boyer Subject: [PATCH 6/7] efi: Allow the "db" UEFI variable to be suppressed Date: Sun, 25 Nov 2018 20:44:59 +0530 X-Mailer: git-send-email 2.13.6 In-Reply-To: <20181125151500.8298-1-nayna@linux.ibm.com> References: <20181125151500.8298-1-nayna@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18112515-0016-0000-0000-0000022C679B X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18112515-0017-0000-0000-00003284B790 Message-Id: <20181125151500.8298-7-nayna@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-11-25_14:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1811250071 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Josh Boyer If a user tells shim to not use the certs/hashes in the UEFI db variable for verification purposes, shim will set a UEFI variable called MokIgnoreDB. Have the uefi import code look for this and ignore the db variable if it is found. Signed-off-by: Josh Boyer Signed-off-by: David Howells Acked-by: Nayna Jain --- Changelog: v0: - No changes security/integrity/platform_certs/load_uefi.c | 44 +++++++++++++++++++++------ 1 file changed, 34 insertions(+), 10 deletions(-) diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c index dbccb45147ef..978c8d0dc151 100644 --- a/security/integrity/platform_certs/load_uefi.c +++ b/security/integrity/platform_certs/load_uefi.c @@ -13,6 +13,26 @@ static __initdata efi_guid_t efi_cert_x509_sha256_guid = EFI_CERT_X509_SHA256_GU static __initdata efi_guid_t efi_cert_sha256_guid = EFI_CERT_SHA256_GUID; /* + * Look to see if a UEFI variable called MokIgnoreDB exists and return true if + * it does. + * + * This UEFI variable is set by the shim if a user tells the shim to not use + * the certs/hashes in the UEFI db variable for verification purposes. If it + * is set, we should ignore the db variable also and the true return indicates + * this. + */ +static __init bool uefi_check_ignore_db(void) +{ + efi_status_t status; + unsigned int db = 0; + unsigned long size = sizeof(db); + efi_guid_t guid = EFI_SHIM_LOCK_GUID; + + status = efi.get_variable(L"MokIgnoreDB", &guid, NULL, &size, &db); + return status == EFI_SUCCESS; +} + +/* * Get a certificate list blob from the named EFI variable. */ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, @@ -113,7 +133,9 @@ static __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_ty } /* - * Load the certs contained in the UEFI databases + * Load the certs contained in the UEFI databases into the secondary trusted + * keyring and the UEFI blacklisted X.509 cert SHA256 hashes into the blacklist + * keyring. */ static int __init load_uefi_certs(void) { @@ -129,15 +151,17 @@ static int __init load_uefi_certs(void) /* Get db, MokListRT, and dbx. They might not exist, so it isn't * an error if we can't get them. */ - db = get_cert_list(L"db", &secure_var, &dbsize); - if (!db) { - pr_err("Couldn't get UEFI db list\n"); - } else { - rc = parse_efi_signature_list("UEFI:db", - db, dbsize, get_handler_for_db); - if (rc) - pr_err("Couldn't parse db signatures: %d\n", rc); - kfree(db); + if (!uefi_check_ignore_db()) { + db = get_cert_list(L"db", &secure_var, &dbsize); + if (!db) { + pr_err("MODSIGN: Couldn't get UEFI db list\n"); + } else { + rc = parse_efi_signature_list("UEFI:db", + db, dbsize, get_handler_for_db); + if (rc) + pr_err("Couldn't parse db signatures: %d\n", rc); + kfree(db); + } } mok = get_cert_list(L"MokListRT", &mok_var, &moksize);