From patchwork Mon Mar 11 11:41:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 10847349 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 2FAE11515 for ; Mon, 11 Mar 2019 11:42:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 19B9D2905A for ; Mon, 11 Mar 2019 11:42:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0BC1D2905C; Mon, 11 Mar 2019 11:42:10 +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=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, 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 656F52905A for ; Mon, 11 Mar 2019 11:42:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727502AbfCKLmI (ORCPT ); Mon, 11 Mar 2019 07:42:08 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:33978 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727493AbfCKLmI (ORCPT ); Mon, 11 Mar 2019 07:42:08 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x2BBdo2Z089635 for ; Mon, 11 Mar 2019 07:42:07 -0400 Received: from e06smtp05.uk.ibm.com (e06smtp05.uk.ibm.com [195.75.94.101]) by mx0b-001b2d01.pphosted.com with ESMTP id 2r5mt3p8q6-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 11 Mar 2019 07:42:06 -0400 Received: from localhost by e06smtp05.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 11 Mar 2019 11:42:05 -0000 Received: from b06cxnps4076.portsmouth.uk.ibm.com (9.149.109.198) by e06smtp05.uk.ibm.com (192.168.101.135) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 11 Mar 2019 11:42:02 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x2BBg1MT25624802 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 11 Mar 2019 11:42:01 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9219A11C05B; Mon, 11 Mar 2019 11:42:01 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 80B5F11C04A; Mon, 11 Mar 2019 11:42:00 +0000 (GMT) Received: from localhost.ibm.com (unknown [9.80.93.170]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 11 Mar 2019 11:42:00 +0000 (GMT) From: Mimi Zohar To: linux-integrity@vger.kernel.org Cc: linux-kselftest@vger.kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Petr Vorel , Dave Young , Matthew Garrett , Mimi Zohar Subject: [PATCH v3 6/7] selftests/ima: loading kernel modules Date: Mon, 11 Mar 2019 07:41:12 -0400 X-Mailer: git-send-email 2.7.5 In-Reply-To: <1552304473-3966-1-git-send-email-zohar@linux.ibm.com> References: <1552304473-3966-1-git-send-email-zohar@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19031111-0020-0000-0000-00000321374B X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19031111-0021-0000-0000-000021735B04 Message-Id: <1552304473-3966-7-git-send-email-zohar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-03-11_09:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1903110088 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP While the appended kernel module signature can be verified, when loading a kernel module via either the init_module or the finit_module syscall, verifying the IMA signature requires access to the file descriptor, which is only available via the finit_module syscall. As "modprobe" does not provide a flag allowing the syscall - init_module or finit_module - to be specified, this patch does not load a kernel module. This test simply verifies that on secure boot enabled systems with "CONFIG_IMA_ARCH_POLICY" configured, that at least an appended kernel module signature or an IMA signature is required based on the Kconfig and the runtime IMA policy. Signed-off-by: Mimi Zohar Reviewed-by: Petr Vorel --- tools/testing/selftests/ima/Makefile | 2 +- tools/testing/selftests/ima/test_kernel_module.sh | 93 +++++++++++++++++++++++ 2 files changed, 94 insertions(+), 1 deletion(-) create mode 100755 tools/testing/selftests/ima/test_kernel_module.sh diff --git a/tools/testing/selftests/ima/Makefile b/tools/testing/selftests/ima/Makefile index 00270de0b637..e1c59c510e1b 100644 --- a/tools/testing/selftests/ima/Makefile +++ b/tools/testing/selftests/ima/Makefile @@ -4,7 +4,7 @@ uname_M := $(shell uname -m 2>/dev/null || echo not) ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/) ifeq ($(ARCH),x86) -TEST_PROGS := test_kexec_load.sh test_kexec_file_load.sh +TEST_PROGS := test_kexec_load.sh test_kexec_file_load.sh test_kernel_module.sh TEST_FILES := ima_common_lib.sh include ../lib.mk diff --git a/tools/testing/selftests/ima/test_kernel_module.sh b/tools/testing/selftests/ima/test_kernel_module.sh new file mode 100755 index 000000000000..319c601b9697 --- /dev/null +++ b/tools/testing/selftests/ima/test_kernel_module.sh @@ -0,0 +1,93 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# On secure boot enabled systems with "CONFIG_IMA_ARCH_POLICY" configured, +# this test verifies that at least an appended kernel module signature or +# an IMA signature is required. It does not attempt to load a kernel module. + +TEST="KERNEL_MODULE" +. ./ima_common_lib.sh + +trap "{ rm -f $IKCONFIG ; }" EXIT + +# Some of the IMA builtin policies may require the kernel modules to +# be signed, but these policy rules may be replaced with a custom +# policy. Only CONFIG_IMA_APPRAISE_REQUIRE_MODULE_SIGS persists after +# loading a custom policy. Check if it is enabled, before reading the +# IMA runtime sysfs policy file. +# Return 1 for IMA signature required and 0 for not required. +is_ima_sig_required() +{ + local ret=0 + + kconfig_enabled "CONFIG_IMA_APPRAISE_REQUIRE_MODULE_SIGS=y" \ + "IMA kernel module signature required" + if [ $? -eq 1 ]; then + return 1 + fi + + # The architecture specific or a custom policy may require the + # kernel module to be signed. Policy rules are walked sequentially. + # As a result, a policy rule may be defined, but might not necessarily + # be used. This test assumes if a policy rule is specified, that is + # the intent. + if [ $ima_read_policy -eq 1 ]; then + check_ima_policy "appraise" "func=MODULE_CHECK" \ + "appraise_type=imasig" + ret=$? + [ $ret -eq 1 ] && log_info "IMA signature required"; + fi + return $ret +} + +# loading kernel modules requires root privileges +require_root_privileges + +# Are appended signatures required? +if [ -e /sys/module/module/parameters/sig_enforce ]; then + sig_enforce=$(cat /sys/module/module/parameters/sig_enforce) + if [ $sig_enforce = "Y" ]; then + log_pass "appended kernel module signature required" + fi +fi + +get_secureboot_mode +if [ $? -eq 0 ]; then + log_skip "secure boot not enabled" +fi + +# get the kernel config +get_kconfig + +# Determine which kernel config options are enabled +kconfig_enabled "CONFIG_IMA_ARCH_POLICY=y" \ + "architecture specific policy enabled" +arch_policy=$? + +kconfig_enabled "CONFIG_MODULE_SIG=y" \ + "appended kernel modules signature enabled" +appended_sig_enabled=$? + +kconfig_enabled "CONFIG_IMA_READ_POLICY=y" "reading IMA policy permitted" +ima_read_policy=$? + +is_ima_sig_required +ima_sig_required=$? + +if [ $arch_policy -eq 0 ]; then + log_skip "architecture specific policy not enabled" +fi + +if [ $appended_sig_enabled -eq 1 ]; then + log_fail "appended kernel module signature enabled, but not required" +fi + +if [ $ima_sig_required -eq 1 ]; then + log_pass "IMA kernel module signature required" +fi + +if [ $ima_read_policy -eq 1 ]; then + log_fail "IMA kernel module signature not required" +else + log_skip "reading IMA policy not permitted" +fi