From patchwork Thu May 24 11:09:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 10424225 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 0BE9F60327 for ; Thu, 24 May 2018 11:10:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 088B92939A for ; Thu, 24 May 2018 11:10:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F0F1C293AD; Thu, 24 May 2018 11:10:45 +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 83C9F2939A for ; Thu, 24 May 2018 11:10:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1033060AbeEXLKl (ORCPT ); Thu, 24 May 2018 07:10:41 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54262 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1032946AbeEXLKh (ORCPT ); Thu, 24 May 2018 07:10:37 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w4OAxkNT092614 for ; Thu, 24 May 2018 07:10:36 -0400 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0b-001b2d01.pphosted.com with ESMTP id 2j5tycktc4-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 24 May 2018 07:10:36 -0400 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 24 May 2018 12:10:34 +0100 Received: from b06cxnps4076.portsmouth.uk.ibm.com (9.149.109.198) by e06smtp12.uk.ibm.com (192.168.101.142) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Thu, 24 May 2018 12:10:31 +0100 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 w4OBAUVp6095244 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 24 May 2018 11:10:30 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 63E6511C04A; Thu, 24 May 2018 12:01:34 +0100 (BST) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EAC2911C054; Thu, 24 May 2018 12:01:32 +0100 (BST) Received: from localhost.ibm.com (unknown [9.80.85.225]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Thu, 24 May 2018 12:01:32 +0100 (BST) From: Mimi Zohar To: linux-integrity@vger.kernel.org Cc: Mimi Zohar , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, David Howells , "Luis R . Rodriguez" , Eric Biederman , kexec@lists.infradead.org, Andres Rodriguez , Greg Kroah-Hartman , Ard Biesheuvel , Kees Cook Subject: [PATCH v3 3/7] ima: based on policy require signed kexec kernel images Date: Thu, 24 May 2018 07:09:32 -0400 X-Mailer: git-send-email 2.7.5 In-Reply-To: <1527160176-29269-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1527160176-29269-1-git-send-email-zohar@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18052411-0008-0000-0000-000004FAA7C3 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18052411-0009-0000-0000-00001E8EAFD2 Message-Id: <1527160176-29269-4-git-send-email-zohar@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-05-24_03:, , 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 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1805240132 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP The original kexec_load syscall can not verify file signatures. This patch differentiates between the kexec_load and kexec_file_load syscalls. Signed-off-by: Mimi Zohar Cc: Eric Biederman Cc: Luis R. Rodriguez Cc: Kees Cook Cc: David Howells Changelog v3: - use switch/case --- security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_main.c | 22 +++++++++++++++++----- security/integrity/ima/ima_policy.c | 2 ++ 3 files changed, 20 insertions(+), 5 deletions(-) diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index 354bb5716ce3..78c15264b17b 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -232,6 +232,7 @@ int ima_policy_show(struct seq_file *m, void *v); #define IMA_APPRAISE_MODULES 0x08 #define IMA_APPRAISE_FIRMWARE 0x10 #define IMA_APPRAISE_POLICY 0x20 +#define IMA_APPRAISE_KEXEC 0x40 #ifdef CONFIG_IMA_APPRAISE int ima_appraise_measurement(enum ima_hooks func, diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index eeb7075868db..fbbcc02a1380 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -432,15 +432,27 @@ void ima_post_path_mknod(struct dentry *dentry) */ int ima_read_data(struct file *file, enum kernel_read_file_id read_id) { - bool sig_enforce = is_module_sig_enforced(); + bool sig_enforce; - if (!file && read_id == READING_MODULE) { - if (!sig_enforce && (ima_appraise & IMA_APPRAISE_MODULES) && - (ima_appraise & IMA_APPRAISE_ENFORCE)) { + if ((ima_appraise & IMA_APPRAISE_ENFORCE) != IMA_APPRAISE_ENFORCE) + return 0; + + switch (read_id) { + case READING_MODULE: + sig_enforce = is_module_sig_enforced(); /* appended sig */ + if (!file && !sig_enforce && + (ima_appraise & IMA_APPRAISE_MODULES)) { pr_err("impossible to appraise a module without a file descriptor. sig_enforce kernel parameter might help\n"); return -EACCES; /* INTEGRITY_UNKNOWN */ } - return 0; /* We rely on module signature checking */ + break; + case READING_KEXEC_IMAGE: + if (!file && (ima_appraise & IMA_APPRAISE_KEXEC)) { + pr_err("impossible to appraise a kernel image without a file descriptor; try using kexec_file syscall.\n"); + return -EACCES; /* INTEGRITY_UNKNOWN */ + } + default: + break; } return 0; } diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 8bbc18eb07eb..c27f6993b07a 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -448,6 +448,8 @@ static int ima_appraise_flag(enum ima_hooks func) return IMA_APPRAISE_FIRMWARE; else if (func == POLICY_CHECK) return IMA_APPRAISE_POLICY; + else if (func == KEXEC_KERNEL_CHECK) + return IMA_APPRAISE_KEXEC; return 0; }