From patchwork Mon Sep 26 17:30:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 9351105 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DE8286077B for ; Mon, 26 Sep 2016 17:56:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D02EC28620 for ; Mon, 26 Sep 2016 17:56:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C31F728B1B; Mon, 26 Sep 2016 17:56:59 +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=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 EFA9528620 for ; Mon, 26 Sep 2016 17:56:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161731AbcIZR45 (ORCPT ); Mon, 26 Sep 2016 13:56:57 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:60977 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161042AbcIZR45 (ORCPT ); Mon, 26 Sep 2016 13:56:57 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u8QHr5s1089149 for ; Mon, 26 Sep 2016 13:56:56 -0400 Received: from e28smtp09.in.ibm.com (e28smtp09.in.ibm.com [125.16.236.9]) by mx0a-001b2d01.pphosted.com with ESMTP id 25q57dht08-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 26 Sep 2016 13:56:56 -0400 Received: from localhost by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 26 Sep 2016 23:26:51 +0530 Received: from d28relay09.in.ibm.com (d28relay09.in.ibm.com [9.184.220.160]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id D0FEC394004E; Mon, 26 Sep 2016 23:26:50 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay09.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u8QHuo1Y26738918; Mon, 26 Sep 2016 23:26:50 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u8QHulA4002690; Mon, 26 Sep 2016 23:26:50 +0530 Received: from localhost.localdomain.localdomain (dhcp-9-2-51-4.watson.ibm.com [9.2.51.4]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u8QHUdYZ008011; Mon, 26 Sep 2016 23:00:58 +0530 From: Mimi Zohar To: linux-security-module Cc: Mimi Zohar , "Eric W. Biederman" , linux-ima-devel@lists.sourceforge.net, Dave Young , kexec@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Thiago Jung Bauermann , Andrew Morton Subject: [PATCH v5 02/10] ima: on soft reboot, restore the measurement list Date: Mon, 26 Sep 2016 13:30:21 -0400 X-Mailer: git-send-email 2.1.0 In-Reply-To: <1474911029-6372-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1474911029-6372-1-git-send-email-zohar@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16092617-0060-0000-0000-0000014B3550 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16092617-0061-0000-0000-00000FE306C0 Message-Id: <1474911029-6372-3-git-send-email-zohar@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-09-26_08:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=8 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1609020000 definitions=main-1609260336 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP The TPM PCRs are only reset on a hard reboot. In order to validate a TPM's quote after a soft reboot (eg. kexec -e), the IMA measurement list of the running kernel must be saved and restored on boot. This patch restores the measurement list. Changelog v5: - replace CONFIG_KEXEC_FILE with architecture CONFIG_HAVE_IMA_KEXEC (Thiago) - replace kexec_get_handover_buffer() with ima_get_kexec_buffer() (Thiago) - replace kexec_free_handover_buffer() with ima_free_kexec_buffer() (Thiago) - remove unnecessary includes from ima_kexec.c (Thiago) - fix off-by-one error when checking hdr_v1->template_name_len (Colin King) Changelog v2: - redefined ima_kexec_hdr to use types with well defined sizes (M. Ellerman) - defined missing ima_load_kexec_buffer() stub function Changelog v1: - call ima_load_kexec_buffer() (Thiago) Signed-off-by: Mimi Zohar --- security/integrity/ima/Makefile | 1 + security/integrity/ima/ima.h | 21 +++++ security/integrity/ima/ima_init.c | 2 + security/integrity/ima/ima_kexec.c | 44 +++++++++ security/integrity/ima/ima_queue.c | 10 ++ security/integrity/ima/ima_template.c | 170 ++++++++++++++++++++++++++++++++++ 6 files changed, 248 insertions(+) create mode 100644 security/integrity/ima/ima_kexec.c diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 9aeaeda..29f198b 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -8,4 +8,5 @@ obj-$(CONFIG_IMA) += ima.o ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \ ima_policy.o ima_template.o ima_template_lib.o ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o +ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index db25f54..51dc8d5 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -28,6 +28,10 @@ #include "../integrity.h" +#ifdef CONFIG_HAVE_IMA_KEXEC +#include +#endif + enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN, IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII }; enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 }; @@ -102,6 +106,21 @@ struct ima_queue_entry { }; extern struct list_head ima_measurements; /* list of all measurements */ +/* Some details preceding the binary serialized measurement list */ +struct ima_kexec_hdr { + u16 version; + u16 _reserved0; + u32 _reserved1; + u64 buffer_size; + u64 count; +}; + +#ifdef CONFIG_HAVE_IMA_KEXEC +void ima_load_kexec_buffer(void); +#else +static inline void ima_load_kexec_buffer(void) {} +#endif /* CONFIG_HAVE_IMA_KEXEC */ + /* Internal IMA function definitions */ int ima_init(void); int ima_fs_init(void); @@ -122,6 +141,8 @@ int ima_init_crypto(void); void ima_putc(struct seq_file *m, void *data, int datalen); void ima_print_digest(struct seq_file *m, u8 *digest, u32 size); struct ima_template_desc *ima_template_desc_current(void); +int ima_restore_measurement_entry(struct ima_template_entry *entry); +int ima_restore_measurement_list(loff_t bufsize, void *buf); int ima_init_template(void); /* diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 32912bd..3ba0ca4 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -128,6 +128,8 @@ int __init ima_init(void) if (rc != 0) return rc; + ima_load_kexec_buffer(); + rc = ima_add_boot_aggregate(); /* boot aggregate must be first entry */ if (rc != 0) return rc; diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c new file mode 100644 index 0000000..36afd0f --- /dev/null +++ b/security/integrity/ima/ima_kexec.c @@ -0,0 +1,44 @@ +/* + * Copyright (C) 2016 IBM Corporation + * + * Authors: + * Thiago Jung Bauermann + * Mimi Zohar + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ +#include "ima.h" + +/* + * Restore the measurement list from the previous kernel. + */ +void ima_load_kexec_buffer(void) +{ + void *kexec_buffer = NULL; + size_t kexec_buffer_size = 0; + int rc; + + rc = ima_get_kexec_buffer(&kexec_buffer, &kexec_buffer_size); + switch (rc) { + case 0: + rc = ima_restore_measurement_list(kexec_buffer_size, + kexec_buffer); + if (rc != 0) + pr_err("Failed to restore the measurement list: %d\n", + rc); + + ima_free_kexec_buffer(); + break; + case -ENOTSUPP: + pr_debug("Restoring the measurement list not supported\n"); + break; + case -ENOENT: + pr_debug("No measurement list to restore\n"); + break; + default: + pr_debug("Error restoring the measurement list: %d\n", rc); + } +} diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c index 32f6ac0..4b1bb77 100644 --- a/security/integrity/ima/ima_queue.c +++ b/security/integrity/ima/ima_queue.c @@ -149,3 +149,13 @@ out: op, audit_cause, result, audit_info); return result; } + +int ima_restore_measurement_entry(struct ima_template_entry *entry) +{ + int result = 0; + + mutex_lock(&ima_extend_list_mutex); + result = ima_add_digest_entry(entry); + mutex_unlock(&ima_extend_list_mutex); + return result; +} diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index febd12e..37f972c 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -37,6 +37,7 @@ static struct ima_template_field supported_fields[] = { {.field_id = "sig", .field_init = ima_eventsig_init, .field_show = ima_show_template_sig}, }; +#define MAX_TEMPLATE_NAME_LEN 15 static struct ima_template_desc *ima_template; static struct ima_template_desc *lookup_template_desc(const char *name); @@ -205,3 +206,172 @@ int __init ima_init_template(void) return result; } + +static int ima_restore_template_data(struct ima_template_desc *template_desc, + void *template_data, + int template_data_size, + struct ima_template_entry **entry) +{ + struct binary_field_data { + u32 len; + u8 data[0]; + } __packed; + + struct binary_field_data *field_data; + int offset = 0; + int ret = 0; + int i; + + *entry = kzalloc(sizeof(**entry) + + template_desc->num_fields * sizeof(struct ima_field_data), + GFP_NOFS); + if (!*entry) + return -ENOMEM; + + (*entry)->template_desc = template_desc; + for (i = 0; i < template_desc->num_fields; i++) { + field_data = template_data + offset; + + /* Each field of the template data is prefixed with a length. */ + if (offset > (template_data_size - sizeof(field_data->len))) { + pr_err("Restoring the template field failed\n"); + ret = -EINVAL; + break; + } + offset += sizeof(field_data->len); + + if (offset > (template_data_size - field_data->len)) { + pr_err("Restoring the template field data failed\n"); + ret = -EINVAL; + break; + } + offset += field_data->len; + + (*entry)->template_data[i].len = field_data->len; + (*entry)->template_data_len += sizeof(field_data->len); + + (*entry)->template_data[i].data = + kzalloc(field_data->len + 1, GFP_KERNEL); + if (!(*entry)->template_data[i].data) { + ret = -ENOMEM; + break; + } + memcpy((*entry)->template_data[i].data, field_data->data, + field_data->len); + (*entry)->template_data_len += field_data->len; + } + + if (ret < 0) { + ima_free_template_entry(*entry); + *entry = NULL; + } + + return ret; +} + +/* Restore the serialized binary measurement list without extending PCRs. */ +int ima_restore_measurement_list(loff_t size, void *buf) +{ + struct binary_hdr_v1 { + u32 pcr; + u8 digest[TPM_DIGEST_SIZE]; + u32 template_name_len; + char template_name[0]; + } __packed; + char template_name[MAX_TEMPLATE_NAME_LEN]; + + struct binary_data_v1 { + u32 template_data_size; + char template_data[0]; + } __packed; + + struct ima_kexec_hdr *khdr = buf; + struct binary_hdr_v1 *hdr_v1; + struct binary_data_v1 *data_v1; + + void *bufp = buf + sizeof(*khdr); + void *bufendp = buf + khdr->buffer_size; + struct ima_template_entry *entry; + struct ima_template_desc *template_desc; + unsigned long count = 0; + int ret = 0; + + if (!buf || size < sizeof(*khdr)) + return 0; + + if (khdr->version != 1) { + pr_err("attempting to restore a incompatible measurement list"); + return 0; + } + + /* + * ima kexec buffer prefix: version, buffer size, count + * v1 format: pcr, digest, template-name-len, template-name, + * template-data-size, template-data + */ + while ((bufp < bufendp) && (count++ < khdr->count)) { + if (count > ULONG_MAX - 1) { + pr_err("attempting to restore too many measurements"); + ret = -EINVAL; + } + + hdr_v1 = bufp; + if ((hdr_v1->template_name_len >= MAX_TEMPLATE_NAME_LEN) || + ((bufp + hdr_v1->template_name_len) > bufendp)) { + pr_err("attempting to restore a template name \ + that is too long\n"); + ret = -EINVAL; + break; + } + bufp += sizeof(*hdr_v1); + + /* template name is not null terminated */ + memcpy(template_name, bufp, hdr_v1->template_name_len); + template_name[hdr_v1->template_name_len] = 0; + + if (strcmp(template_name, "ima") == 0) { + pr_err("attempting to restore an unsupported \ + template \"%s\" failed\n", template_name); + ret = -EINVAL; + break; + } + data_v1 = bufp += (u_int8_t)hdr_v1->template_name_len; + + /* get template format */ + template_desc = lookup_template_desc(template_name); + if (!template_desc) { + pr_err("template \"%s\" not found\n", template_name); + ret = -EINVAL; + break; + } + + if (bufp > (bufendp - sizeof(data_v1->template_data_size))) { + pr_err("restoring the template data size failed\n"); + ret = -EINVAL; + break; + } + bufp += (u_int8_t) sizeof(data_v1->template_data_size); + + if (bufp > (bufendp - data_v1->template_data_size)) { + pr_err("restoring the template data failed\n"); + ret = -EINVAL; + break; + } + + ret = ima_restore_template_data(template_desc, + data_v1->template_data, + data_v1->template_data_size, + &entry); + if (ret < 0) + break; + + memcpy(entry->digest, hdr_v1->digest, TPM_DIGEST_SIZE); + entry->pcr = hdr_v1->pcr; + ret = ima_restore_measurement_entry(entry); + if (ret < 0) + break; + + bufp += data_v1->template_data_size; + } + return ret; +}