From patchwork Wed Aug 26 03:44:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lenny Szubowicz X-Patchwork-Id: 11737163 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 4029C913 for ; Wed, 26 Aug 2020 03:45:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2878C20707 for ; Wed, 26 Aug 2020 03:45:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="JbSs19tY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726840AbgHZDpQ (ORCPT ); Tue, 25 Aug 2020 23:45:16 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:53148 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726831AbgHZDpP (ORCPT ); Tue, 25 Aug 2020 23:45:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1598413514; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:in-reply-to:in-reply-to:references:references; bh=8T5WfWs/Tv1MkqhnVgGnky3bmtEaukh+fceB8s7dUAI=; b=JbSs19tYAUlt2NlcikDLRUwsOm//2U+CGgeX7EyTpNPvx+MbDFDEhDQ7t7/eNYhBezQWrN 9tH98rF6JqsxItW8lKozV3CZ81hQk00YwqF+/euaqBJZBPBrqWR0pvXUmhbXpf4bYQwxku tGOyPyfk653aKUqpSsYm1XnyuLlxXpU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-293-MeUhVzXSOAKGS-OxOO4fTw-1; Tue, 25 Aug 2020 23:45:12 -0400 X-MC-Unique: MeUhVzXSOAKGS-OxOO4fTw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AFA0F1DDE0; Wed, 26 Aug 2020 03:45:10 +0000 (UTC) Received: from lszubowi.redhat.com (unknown [10.10.110.32]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5588B5D9E4; Wed, 26 Aug 2020 03:45:08 +0000 (UTC) From: Lenny Szubowicz To: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-security-module@vger.kernel.org, ardb@kernel.org, jmorris@namei.org, serge@hallyn.com, keescook@chromium.org, zohar@linux.ibm.com, bp@alien8.de, pjones@redhat.com, dhowells@redhat.com, prarit@redhat.com Subject: [PATCH 3/3] integrity: Load certs from the EFI MOK config table Date: Tue, 25 Aug 2020 23:44:55 -0400 Message-Id: <20200826034455.28707-4-lszubowi@redhat.com> In-Reply-To: <20200826034455.28707-1-lszubowi@redhat.com> References: <20200826034455.28707-1-lszubowi@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Because of system-specific EFI firmware limitations, EFI volatile variables may not be capable of holding the required contents of the Machine Owner Key (MOK) certificate store. Therefore, an EFI boot loader may pass the MOK certs via a EFI configuration table created specifically for this purpose to avoid this firmware limitation. An EFI configuration table is a much more primitive mechanism compared to EFI variables and is well suited for one-way passage of static information from a pre-OS environment to the kernel. This patch adds the support to load certs from the MokListRT entry in the MOK variable configuration table, if it's present. The pre-existing support to load certs from the MokListRT EFI variable remains and is used if the EFI MOK configuration table isn't present or can't be successfully used. Signed-off-by: Lenny Szubowicz --- security/integrity/platform_certs/load_uefi.c | 22 +++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c index 547410d8ffa5..2c9c847d9b62 100644 --- a/security/integrity/platform_certs/load_uefi.c +++ b/security/integrity/platform_certs/load_uefi.c @@ -72,6 +72,9 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, * * Load the certs contained in the UEFI MokListRT database into the * platform trusted keyring. + * + * This routine checks the EFI MOK config table first. If and only if + * that fails, this routine uses the MokListRT ordinary UEFI variable. */ static int __init load_moklist_certs(void) { @@ -79,8 +82,27 @@ static int __init load_moklist_certs(void) void *mok = NULL; unsigned long moksize = 0; efi_status_t status; + struct efi_mokvar_table_entry *mokvar_entry = NULL; int rc = 0; + /* First try to load certs from the EFI MOKvar config table. + * It's not an error if the MOKvar config table doesn't exist + * or the MokListRT entry is not found in it. + */ + mokvar_entry = efi_mokvar_entry_find("MokListRT"); + if (mokvar_entry) { + rc = parse_efi_signature_list("UEFI:MokListRT (MOKvar table)", + mokvar_entry->data, + mokvar_entry->data_size, + get_handler_for_db); + /* All done if that worked. */ + if (!rc) + return rc; + + pr_err("Couldn't parse MokListRT signatures from EFI MOKvar config table: %d\n", + rc); + } + /* Get MokListRT. It might not exist, so it isn't an error * if we can't get it. */