From patchwork Fri May 17 21:39:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Garrett X-Patchwork-Id: 10948659 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 0AAC714DB for ; Fri, 17 May 2019 21:39:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EE1072847E for ; Fri, 17 May 2019 21:39:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E233628481; Fri, 17 May 2019 21:39:35 +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=-14.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,RCVD_IN_DNSWL_HI,USER_IN_DEF_DKIM_WL autolearn=ham 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 5DFEA2847E for ; Fri, 17 May 2019 21:39:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729606AbfEQVjd (ORCPT ); Fri, 17 May 2019 17:39:33 -0400 Received: from mail-qk1-f202.google.com ([209.85.222.202]:47966 "EHLO mail-qk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729623AbfEQVjd (ORCPT ); Fri, 17 May 2019 17:39:33 -0400 Received: by mail-qk1-f202.google.com with SMTP id l185so1998626qkd.14 for ; Fri, 17 May 2019 14:39:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=/ITrQNIi0NTjerZ5MiR7r+4SVrslKsoTGUVP7IEv6kU=; b=EQVVmRZXphR6AKeVQ4JSoeX5ztR2+S1HUTR1XM5/6QvgP1eBiAXVWL3Ro0ebl1UuQU U7IMllkNfVgGtOvqZhrKhuiM/Pmm/bQ0WaDVwgWs4bIR9+VOFHmCUxcyJVwGGaRJ8HPC LEfCOxuK2SlCVJ3xuvJVjzewGoWYg6RJlVtdlfeVYegnHznxZWo7LOsiEOmPaTY5Kyg2 r2bCvjNjnIlbxAXrZrlySsa+IRF2Y3qRZkqjjuUS1gPsphxbbWbwUNh2TkkaILJBEkCf L99WWMZx63g9f3xLjPfZqME23QkJo6o/Sc3EIg8HsbGNBiseDxLcQyc5zjang4tRyEur XUMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=/ITrQNIi0NTjerZ5MiR7r+4SVrslKsoTGUVP7IEv6kU=; b=dyN5aHc8oyak4vNPsQebNaXIzRZ0/wH7BCQ4iV30D0wYXufGnOD3cHkL6yQdbBMVLf sRrp5uWkbY4sxRS5gkKuktiNunPgKDz8PbTGsMF3f7u0wpAruAfADo1yjLAoUGWzMe0w 9rid20TVZ48nmu6aquqR+kunHuUsKuBQylmsHE/ILxknfkEWG4H6maaRMdBbV8FZteho eTxfBtcC5Qa0xtKzrKtudmyPxnFZ87DP1DKZGJTH+IEFzrzyeCZC9TxV/l2JRL0gUztg Usv89TuBM9JfpWVPwfBaGrIHuuo82D9X05XKHnSa7ZG8k5zTCA+TC4nOz0JFSs8hG/p+ CmuQ== X-Gm-Message-State: APjAAAVOWlTPT0+cf49n/sXPyiyNgVWwli2FBUq9G9aS5gjuiJ8sc9r4 lRaEl3I4a1E7A2A5+luVMaZf55Nzx0QoTN5asU9XyQ== X-Google-Smtp-Source: APXvYqxuE90XrZHB/VO7+Xrb4zeWDdpZr9ZkE2jFp92Gxnl0nXadyAYNdgO+zMIR06dwvERZz59AduFXGXMHenfcK2FqyA== X-Received: by 2002:a37:34b:: with SMTP id 72mr46524708qkd.42.1558129172544; Fri, 17 May 2019 14:39:32 -0700 (PDT) Date: Fri, 17 May 2019 14:39:18 -0700 In-Reply-To: <20190517213918.26045-1-matthewgarrett@google.com> Message-Id: <20190517213918.26045-5-matthewgarrett@google.com> Mime-Version: 1.0 References: <20190517213918.26045-1-matthewgarrett@google.com> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog Subject: [PATCH V6 4/4] efi: Attempt to get the TCG2 event log in the boot stub From: Matthew Garrett To: linux-integrity@vger.kernel.org Cc: peterhuewe@gmx.de, jarkko.sakkinen@linux.intel.com, jgg@ziepe.ca, roberto.sassu@huawei.com, linux-efi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, tweek@google.com, bsz@semihalf.com, Matthew Garrett Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Matthew Garrett Right now we only attempt to obtain the SHA1-only event log. The protocol also supports a crypto agile log format, which contains digests for all algorithms in use. Attempt to obtain this first, and fall back to obtaining the older format if the system doesn't support it. This is lightly complicated by the event sizes being variable (as we don't know in advance which algorithms are in use), and the interface giving us back a pointer to the start of the final entry rather than a pointer to the end of the log - as a result, we need to parse the final entry to figure out its length in order to know how much data to copy up to the OS. Signed-off-by: Matthew Garrett Tested-by: Jarkko Sakkinen Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/firmware/efi/libstub/tpm.c | 57 ++++++++++++++++++++---------- 1 file changed, 39 insertions(+), 18 deletions(-) diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c index 5bd04f75d8d6..b3f30448e454 100644 --- a/drivers/firmware/efi/libstub/tpm.c +++ b/drivers/firmware/efi/libstub/tpm.c @@ -8,8 +8,13 @@ * Thiebaud Weksteen */ #include -#include #include +/* + * KASAN redefines memcpy() in a way that isn't available in the EFI stub. + * We need to include asm/efi.h before linux/tpm_eventlog.h in order to avoid + * the wrong memcpy() being referenced. + */ +#include #include "efistub.h" @@ -57,7 +62,7 @@ void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) #endif -static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) +void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) { efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID; @@ -67,6 +72,7 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) unsigned long first_entry_addr, last_entry_addr; size_t log_size, last_entry_size; efi_bool_t truncated; + int version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_2; void *tcg2_protocol = NULL; status = efi_call_early(locate_protocol, &tcg2_guid, NULL, @@ -74,14 +80,20 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) if (status != EFI_SUCCESS) return; - status = efi_call_proto(efi_tcg2_protocol, get_event_log, tcg2_protocol, - EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2, - &log_location, &log_last_entry, &truncated); - if (status != EFI_SUCCESS) - return; + status = efi_call_proto(efi_tcg2_protocol, get_event_log, + tcg2_protocol, version, &log_location, + &log_last_entry, &truncated); + + if (status != EFI_SUCCESS || !log_location) { + version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + status = efi_call_proto(efi_tcg2_protocol, get_event_log, + tcg2_protocol, version, &log_location, + &log_last_entry, &truncated); + if (status != EFI_SUCCESS || !log_location) + return; + + } - if (!log_location) - return; first_entry_addr = (unsigned long) log_location; /* @@ -96,8 +108,23 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) * We need to calculate its size to deduce the full size of * the logs. */ - last_entry_size = sizeof(struct tcpa_event) + - ((struct tcpa_event *) last_entry_addr)->event_size; + if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) { + /* + * The TCG2 log format has variable length entries, + * and the information to decode the hash algorithms + * back into a size is contained in the first entry - + * pass a pointer to the final entry (to calculate its + * size) and the first entry (so we know how long each + * digest is) + */ + last_entry_size = + __calc_tpm2_event_size((void *)last_entry_addr, + (void *)(long)log_location, + false); + } else { + last_entry_size = sizeof(struct tcpa_event) + + ((struct tcpa_event *) last_entry_addr)->event_size; + } log_size = log_last_entry - log_location + last_entry_size; } @@ -114,7 +141,7 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) memset(log_tbl, 0, sizeof(*log_tbl) + log_size); log_tbl->size = log_size; - log_tbl->version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + log_tbl->version = version; memcpy(log_tbl->log, (void *) first_entry_addr, log_size); status = efi_call_early(install_configuration_table, @@ -126,9 +153,3 @@ static void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) err_free: efi_call_early(free_pool, log_tbl); } - -void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) -{ - /* Only try to retrieve the logs in 1.2 format. */ - efi_retrieve_tpm2_eventlog_1_2(sys_table_arg); -}