From patchwork Wed Mar 10 22:19:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Berger X-Patchwork-Id: 12129653 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A44DC432C3 for ; Wed, 10 Mar 2021 22:20:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2C8F64FDC for ; Wed, 10 Mar 2021 22:20:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229971AbhCJWTv (ORCPT ); Wed, 10 Mar 2021 17:19:51 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:18292 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232966AbhCJWTe (ORCPT ); Wed, 10 Mar 2021 17:19:34 -0500 Received: from pps.filterd (m0098409.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12AMJV77081017; Wed, 10 Mar 2021 17:19:33 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=wp/1c5NfMQfPydumePHhOuQQCmguw6uJmxK59NQNMnY=; b=baw+OEcxKGWKd+5Tc25jUfb6faVvpZEHJhBLRTbjqfZlDCfhZYGfcZL2+adUXNGo6lZZ uwbzF8+fjrXTIficXWt7Lu25AoCCSynW/5St7/821IFX236Nh/4lVgJUVDpEc8+UFnC9 KxgKFhBuUVFGw2rO6+Tu68Fip5mCe/LwraLJ+Qh+pmXSq9gdoFcN0i080kJNwXVsIu7k uZnN6UfaInqN9m3DvDLkk55JtPbiASbOV6I4wWHvtleuCov1/fagRuQM/QmxXtXWFnYU JQAP8CSwuxUI+k6akcrWZ2JTRCfD8kbVtjAaT6fywFf1UHPUM8ux7FIYNcEr790esmV5 Sg== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 3774mduumm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 10 Mar 2021 17:19:33 -0500 Received: from m0098409.ppops.net (m0098409.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 12AMJXWf081172; Wed, 10 Mar 2021 17:19:33 -0500 Received: from ppma04wdc.us.ibm.com (1a.90.2fa9.ip4.static.sl-reverse.com [169.47.144.26]) by mx0a-001b2d01.pphosted.com with ESMTP id 3774mduuhn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 10 Mar 2021 17:19:32 -0500 Received: from pps.filterd (ppma04wdc.us.ibm.com [127.0.0.1]) by ppma04wdc.us.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 12AMH8Up021205; Wed, 10 Mar 2021 22:19:19 GMT Received: from b01cxnp22033.gho.pok.ibm.com (b01cxnp22033.gho.pok.ibm.com [9.57.198.23]) by ppma04wdc.us.ibm.com with ESMTP id 3768n4k8w1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 10 Mar 2021 22:19:19 +0000 Received: from b01ledav005.gho.pok.ibm.com (b01ledav005.gho.pok.ibm.com [9.57.199.110]) by b01cxnp22033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 12AMJJMO27066708 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 10 Mar 2021 22:19:19 GMT Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 7A5E9AE062; Wed, 10 Mar 2021 22:19:19 +0000 (GMT) Received: from b01ledav005.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6284DAE06B; Wed, 10 Mar 2021 22:19:19 +0000 (GMT) Received: from localhost.localdomain (unknown [9.47.158.152]) by b01ledav005.gho.pok.ibm.com (Postfix) with ESMTP; Wed, 10 Mar 2021 22:19:19 +0000 (GMT) From: Stefan Berger To: peterhuewe@gmx.de, jarkko@kernel.org Cc: jgg@ziepe.ca, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Stefan Berger Subject: [PATCH v2 2/3] tpm: acpi: Check eventlog signature before using it Date: Wed, 10 Mar 2021 17:19:15 -0500 Message-Id: <20210310221916.356716-3-stefanb@linux.ibm.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210310221916.356716-1-stefanb@linux.ibm.com> References: <20210310221916.356716-1-stefanb@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369,18.0.761 definitions=2021-03-10_12:2021-03-10,2021-03-10 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 impostorscore=0 spamscore=0 mlxscore=0 lowpriorityscore=0 adultscore=0 mlxlogscore=999 bulkscore=0 malwarescore=0 clxscore=1015 priorityscore=1501 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2103100105 Precedence: bulk List-ID: Check the eventlog signature before using it. This avoids using an empty log, as may be the case when QEMU created the ACPI tables, rather than probing the EFI log next. This resolves an issue where the EFI log was empty since an empty ACPI log was used. Fixes: 85467f63a05c ("tpm: Add support for event log pointer found in TPM2 ACPI table") Signed-off-by: Stefan Berger Reviewed-by: Jarkko Sakkinen --- drivers/char/tpm/eventlog/acpi.c | 33 +++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c index 3633ed70f48f..1b18ce5ebab1 100644 --- a/drivers/char/tpm/eventlog/acpi.c +++ b/drivers/char/tpm/eventlog/acpi.c @@ -41,6 +41,27 @@ struct acpi_tcpa { }; }; +/* Check that the given log is indeed a TPM2 log. */ +static bool tpm_is_tpm2_log(void *bios_event_log, u64 len) +{ + struct tcg_efi_specid_event_head *efispecid; + struct tcg_pcr_event *event_header; + int n; + + if (len < sizeof(*event_header)) + return false; + len -= sizeof(*event_header); + event_header = bios_event_log; + + if (len < sizeof(*efispecid)) + return false; + efispecid = (struct tcg_efi_specid_event_head *)event_header->event; + + n = memcmp(efispecid->signature, TCG_SPECID_SIG, + sizeof(TCG_SPECID_SIG)); + return n == 0; +} + /* read binary bios log */ int tpm_read_log_acpi(struct tpm_chip *chip) { @@ -52,6 +73,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip) struct acpi_table_tpm2 *tbl; struct acpi_tpm2_phy *tpm2_phy; int format; + int ret; log = &chip->log; @@ -112,6 +134,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip) log->bios_event_log_end = log->bios_event_log + len; + ret = -EIO; virt = acpi_os_map_iomem(start, len); if (!virt) goto err; @@ -119,11 +142,19 @@ int tpm_read_log_acpi(struct tpm_chip *chip) memcpy_fromio(log->bios_event_log, virt, len); acpi_os_unmap_iomem(virt, len); + + if (chip->flags & TPM_CHIP_FLAG_TPM2 && + !tpm_is_tpm2_log(log->bios_event_log, len)) { + /* try EFI log next */ + ret = -ENODEV; + goto err; + } + return format; err: kfree(log->bios_event_log); log->bios_event_log = NULL; - return -EIO; + return ret; }