From patchwork Mon Sep 14 11:50:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Trammell Hudson X-Patchwork-Id: 11773619 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 C025F92C for ; Mon, 14 Sep 2020 11:51:52 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9F3E121741 for ; Mon, 14 Sep 2020 11:51:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9F3E121741 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=trmm.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kHn0P-0005gX-FE; Mon, 14 Sep 2020 11:50:45 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kHn0O-0005e0-MA for xen-devel@lists.xenproject.org; Mon, 14 Sep 2020 11:50:44 +0000 X-Inumbo-ID: 4d045823-b3ed-4de6-8737-c86d8cf78198 Received: from mx1a.swcp.com (unknown [216.184.2.64]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 4d045823-b3ed-4de6-8737-c86d8cf78198; Mon, 14 Sep 2020 11:50:41 +0000 (UTC) Received: from ame7.swcp.com (ame7.swcp.com [216.184.2.70]) by mx1a.swcp.com (8.14.4/8.14.4/Debian-4) with ESMTP id 08EBodxJ013974; Mon, 14 Sep 2020 05:50:39 -0600 Received-SPF: neutral (ame7.swcp.com: 62.251.112.184 is neither permitted nor denied by domain of hudson@trmm.net) receiver=ame7.swcp.com; client-ip=62.251.112.184; helo=diamond.fritz.box; envelope-from=hudson@trmm.net; x-software=spfmilter 2.001 http://www.acme.com/software/spfmilter/ with libspf2-1.2.10; Received: from diamond.fritz.box (62-251-112-184.ip.xs4all.nl [62.251.112.184]) by ame7.swcp.com (8.15.2/8.15.2) with ESMTP id 08EBoFiL022702; Mon, 14 Sep 2020 05:50:36 -0600 (MDT) (envelope-from hudson@trmm.net) X-Authentication-Warning: ame7.swcp.com: Host 62-251-112-184.ip.xs4all.nl [62.251.112.184] claimed to be diamond.fritz.box From: Trammell Hudson To: xen-devel@lists.xenproject.org Cc: roger.pau@citrix.com, jbeulich@suse.com, andrew.cooper3@citrix.com, wl@xen.org Subject: [PATCH v4 4/4] efi: Do not use command line if secure boot is enabled. Date: Mon, 14 Sep 2020 07:50:13 -0400 Message-Id: <20200914115013.814079-5-hudson@trmm.net> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200914115013.814079-1-hudson@trmm.net> References: <20200914115013.814079-1-hudson@trmm.net> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.83 X-Greylist: Message whitelisted by DRAC access database, not delayed by milter-greylist-4.6.2 (ame7.swcp.com [216.184.2.128]); Mon, 14 Sep 2020 05:50:38 -0600 (MDT) X-Virus-Scanned: clamav-milter 0.100.2 at ame7 X-Virus-Status: Clean X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on ame7.swcp.com X-Spam-Status: No, hits=0.7 tests=NO_RECEIVED,NO_RELAYS,SPF_NEUTRAL version=3.4.2 X-Spam-Level: X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" If secure boot is enabled, the Xen command line arguments are ignored. If a unified Xen image is used, then the bundled configuration, dom0 kernel, and initrd are prefered over the ones listed in the config file. Unlike the shim based verification, the PE signature on a unified image covers the all of the Xen+config+kernel+initrd modules linked into the unified image. This also ensures that properly configured platforms will measure the entire runtime into the TPM for unsealing secrets or remote attestation. Signed-off-by: Trammell Hudson --- xen/common/efi/boot.c | 44 ++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 3 deletions(-) diff --git a/xen/common/efi/boot.c b/xen/common/efi/boot.c index 4b1fbc9643..e65c1f1a09 100644 --- a/xen/common/efi/boot.c +++ b/xen/common/efi/boot.c @@ -949,6 +949,39 @@ static void __init setup_efi_pci(void) efi_bs->FreePool(handles); } +/* + * Logic should remain sync'ed with linux/arch/x86/xen/efi.c + * Secure Boot is enabled iff 'SecureBoot' is set and the system is + * not in Setup Mode. + */ +static bool __init efi_secure_boot(void) +{ + static const __initconst EFI_GUID global_guid = EFI_GLOBAL_VARIABLE; + uint8_t secboot, setupmode; + UINTN secboot_size = sizeof(secboot); + UINTN setupmode_size = sizeof(setupmode); + EFI_STATUS rc; + + rc = efi_rs->GetVariable(L"SecureBoot", (EFI_GUID *)&global_guid, + NULL, &secboot_size, &secboot); + if ( rc != EFI_SUCCESS ) + return false; + + rc = efi_rs->GetVariable(L"SetupMode", (EFI_GUID *)&global_guid, + NULL, &setupmode_size, &setupmode); + if ( rc != EFI_SUCCESS ) + return false; + + if ( secboot > 1) + { + PrintStr(L"Invalid SecureBoot variable=0x"); + DisplayUint(secboot, 2); + PrintStr(newline); + } + + return secboot == 1 && setupmode == 0; +} + static void __init efi_variables(void) { EFI_STATUS status; @@ -1125,8 +1158,8 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) static EFI_GUID __initdata shim_lock_guid = SHIM_LOCK_PROTOCOL_GUID; EFI_LOADED_IMAGE *loaded_image; EFI_STATUS status; - unsigned int i, argc; - CHAR16 **argv, *file_name, *cfg_file_name = NULL, *options = NULL; + unsigned int i, argc = 0; + CHAR16 **argv = NULL, *file_name, *cfg_file_name = NULL, *options = NULL; UINTN gop_mode = ~0; EFI_SHIM_LOCK_PROTOCOL *shim_lock; EFI_GRAPHICS_OUTPUT_PROTOCOL *gop = NULL; @@ -1134,6 +1167,7 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) bool base_video = false; char *option_str; bool use_cfg_file; + bool secure = false; __set_bit(EFI_BOOT, &efi_flags); __set_bit(EFI_LOADER, &efi_flags); @@ -1152,8 +1186,10 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) PrintErrMesg(L"No Loaded Image Protocol", status); efi_arch_load_addr_check(loaded_image); + secure = efi_secure_boot(); - if ( use_cfg_file ) + /* If UEFI Secure Boot is enabled, do not parse the command line */ + if ( use_cfg_file && !secure ) { UINTN offset = 0; @@ -1211,6 +1247,8 @@ efi_start(EFI_HANDLE ImageHandle, EFI_SYSTEM_TABLE *SystemTable) PrintStr(L"Xen " __stringify(XEN_VERSION) "." __stringify(XEN_SUBVERSION) XEN_EXTRAVERSION " (c/s " XEN_CHANGESET ") EFI loader\r\n"); + if ( secure ) + PrintStr(L"UEFI Secure Boot enabled\r\n"); efi_arch_relocate_image(0);