From patchwork Fri Oct 5 17:40:15 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nayna X-Patchwork-Id: 10628569 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 D603D15A6 for ; Fri, 5 Oct 2018 17:43:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C26B129B27 for ; Fri, 5 Oct 2018 17:43:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B634629B41; Fri, 5 Oct 2018 17:43:59 +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 9C48F29B27 for ; Fri, 5 Oct 2018 17:43:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729136AbeJFAnm (ORCPT ); Fri, 5 Oct 2018 20:43:42 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:45312 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729123AbeJFAnl (ORCPT ); Fri, 5 Oct 2018 20:43:41 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w95HdTZ1100502 for ; Fri, 5 Oct 2018 13:43:56 -0400 Received: from e06smtp02.uk.ibm.com (e06smtp02.uk.ibm.com [195.75.94.98]) by mx0a-001b2d01.pphosted.com with ESMTP id 2mxat7djqm-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 05 Oct 2018 13:43:56 -0400 Received: from localhost by e06smtp02.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) Fri, 5 Oct 2018 18:43:50 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w95HhmZR61079676 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 5 Oct 2018 17:43:48 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 718D511C058; Fri, 5 Oct 2018 20:43:24 +0100 (BST) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BA13911C04C; Fri, 5 Oct 2018 20:43:20 +0100 (BST) Received: from swastik.in.ibm.com (unknown [9.124.221.60]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 5 Oct 2018 20:43:20 +0100 (BST) From: Nayna Jain To: linux-integrity@vger.kernel.org Cc: zohar@linux.ibm.com, linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, dhowells@redhat.com, jforbes@redhat.com, seth.forshee@canonical.com, kexec@lists.infradead.org, Eric Richter , Nayna Jain Subject: [PATCH v5 5/5] x86/ima: define arch_get_ima_policy() for x86 Date: Fri, 5 Oct 2018 23:10:15 +0530 X-Mailer: git-send-email 2.13.6 In-Reply-To: <20181005174015.21939-1-nayna@linux.vnet.ibm.com> References: <20181005174015.21939-1-nayna@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18100517-0008-0000-0000-0000027B88DD X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18100517-0009-0000-0000-000021E4B4D4 Message-Id: <20181005174015.21939-6-nayna@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-10-05_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=8.0.1-1807170000 definitions=main-1810050174 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP From: Eric Richter On x86, there are two methods of verifying a kexec'ed kernel image signature being loaded via the kexec_file_load syscall - an architecture specific implementaton or a IMA KEXEC_KERNEL_CHECK appraisal rule. Neither of these methods verify the kexec'ed kernel image signature being loaded via the kexec_load syscall. Secure boot enabled systems require kexec images to be signed. Therefore, this patch loads an IMA KEXEC_KERNEL_CHECK policy rule on secure boot enabled systems not configured with CONFIG_KEXEC_VERIFY_SIG enabled. When IMA_APPRAISE_BOOTPARAM is configured, different IMA appraise modes (eg. fix, log) can be specified on the boot command line, allowing unsigned or invalidly signed kernel images to be kexec'ed. This patch permits enabling IMA_APPRAISE_BOOTPARAM or IMA_ARCH_POLICY, but not both. Signed-off-by: Eric Richter - Removed the policy KEXEC_ORIG_KERNEL_CHECK which was defined to disable the kexec_load syscall. - arch_get_ima_policy() uses arch_ima_get_secureboot() to get secureboot state Signed-off-by: Nayna Jain --- arch/x86/kernel/ima_arch.c | 18 ++++++++++++++++++ include/linux/ima.h | 4 ++++ security/integrity/ima/Kconfig | 10 +++++++++- 3 files changed, 31 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c index bb5a88d2b271..245976e49a55 100644 --- a/arch/x86/kernel/ima_arch.c +++ b/arch/x86/kernel/ima_arch.c @@ -15,3 +15,21 @@ bool arch_ima_get_secureboot(void) else return false; } + +/* arch rules for audit and user mode */ +static const char * const sb_arch_rules[] = { +#ifndef CONFIG_KEXEC_VERIFY_SIG + "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig", +#endif /* CONFIG_KEXEC_VERIFY_SIG */ + "measure func=KEXEC_KERNEL_CHECK", + NULL +}; + +#ifdef CONFIG_IMA_ARCH_POLICY +const char * const *arch_get_ima_policy(void) +{ + if (arch_ima_get_secureboot()) + return sb_arch_rules; + return NULL; +} +#endif diff --git a/include/linux/ima.h b/include/linux/ima.h index 350fa957f8a6..dabd3abdf671 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -39,10 +39,14 @@ static inline bool arch_ima_get_secureboot(void) } #endif +#if defined(CONFIG_X86) && defined(CONFIG_IMA_ARCH_POLICY) +extern const char * const *arch_get_ima_policy(void); +#else static inline const char * const *arch_get_ima_policy(void) { return NULL; } +#endif #else static inline int ima_bprm_check(struct linux_binprm *bprm) diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 13b446328dda..a18f8c6d13b5 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -157,6 +157,14 @@ config IMA_APPRAISE If unsure, say N. +config IMA_ARCH_POLICY + bool "Enable loading an IMA architecture specific policy" + depends on KEXEC_VERIFY_SIG || IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS + default n + help + This option enables loading an IMA architecture specific policy + based on run time secure boot flags. + config IMA_APPRAISE_BUILD_POLICY bool "IMA build time configured policy rules" depends on IMA_APPRAISE && INTEGRITY_ASYMMETRIC_KEYS @@ -217,7 +225,7 @@ config IMA_APPRAISE_REQUIRE_POLICY_SIGS config IMA_APPRAISE_BOOTPARAM bool "ima_appraise boot parameter" - depends on IMA_APPRAISE + depends on IMA_APPRAISE && !IMA_ARCH_POLICY default y help This option enables the different "ima_appraise=" modes