From patchwork Tue Feb 26 23:27:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 10830913 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 6258F1575 for ; Tue, 26 Feb 2019 23:28:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4BF212D519 for ; Tue, 26 Feb 2019 23:28:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4033A2D531; Tue, 26 Feb 2019 23:28:00 +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 AE3802D51E for ; Tue, 26 Feb 2019 23:27:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729455AbfBZX15 (ORCPT ); Tue, 26 Feb 2019 18:27:57 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:54774 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729432AbfBZX14 (ORCPT ); Tue, 26 Feb 2019 18:27:56 -0500 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1QNNvTj137772 for ; Tue, 26 Feb 2019 18:27:56 -0500 Received: from e06smtp04.uk.ibm.com (e06smtp04.uk.ibm.com [195.75.94.100]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qwd6x5m50-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 26 Feb 2019 18:27:56 -0500 Received: from localhost by e06smtp04.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 26 Feb 2019 23:27:50 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1QNRn1722937626 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 26 Feb 2019 23:27:50 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DB553A4055; Tue, 26 Feb 2019 23:27:49 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2C775A4051; Tue, 26 Feb 2019 23:27:49 +0000 (GMT) Received: from localhost.ibm.com (unknown [9.80.106.105]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 26 Feb 2019 23:27:49 +0000 (GMT) From: Mimi Zohar To: linux-kselftest@vger.kernel.org, Shuah Khan Cc: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, Mimi Zohar Subject: [PATCH v2 5/5] selftests/ima: loading kernel modules Date: Tue, 26 Feb 2019 18:27:00 -0500 X-Mailer: git-send-email 2.7.5 In-Reply-To: <1551223620-11586-1-git-send-email-zohar@linux.ibm.com> References: <1551223620-11586-1-git-send-email-zohar@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 19022623-0016-0000-0000-0000025B496E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19022623-0017-0000-0000-000032B5AE3E Message-Id: <1551223620-11586-6-git-send-email-zohar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-02-26_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 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-1902260158 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@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 | 96 +++++++++++++++++++++++ 2 files changed, 97 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 049c83c9426c..ef5201ff0bea 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 := 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..4009e1b60b03 --- /dev/null +++ b/tools/testing/selftests/ima/test_kernel_module.sh @@ -0,0 +1,96 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0-or-later +# +# 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" +. ./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 + log_info "IMA kernel module signature required" + 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 +if [ $(id -ru) -ne 0 ]; then + log_skip "requires root privileges" +fi + +# Are appended signatures required? +if [ -e /sys/module/module/parameters/sig_enforce ]; then + sig_enforce=$(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