From patchwork Mon Apr 30 19:01:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 10372245 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 764A16032A for ; Mon, 30 Apr 2018 19:01:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 66A14285B0 for ; Mon, 30 Apr 2018 19:01:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5AEA428AD4; Mon, 30 Apr 2018 19:01:55 +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=unavailable 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 E59CE285B0 for ; Mon, 30 Apr 2018 19:01:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754600AbeD3TBl (ORCPT ); Mon, 30 Apr 2018 15:01:41 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:58876 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754398AbeD3TBk (ORCPT ); Mon, 30 Apr 2018 15:01:40 -0400 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w3UIxF6Z159526 for ; Mon, 30 Apr 2018 15:01:39 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 2hp4wpjr8j-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 30 Apr 2018 15:01:39 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Mon, 30 Apr 2018 20:01:36 +0100 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06cxnps3075.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w3UJ1Z5p8454456; Mon, 30 Apr 2018 19:01:35 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0C2334C04A; Mon, 30 Apr 2018 19:53:48 +0100 (BST) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 5950D4C046; Mon, 30 Apr 2018 19:53:47 +0100 (BST) Received: from dhcp-9-2-55-242.watson.ibm.com (unknown [9.2.55.242]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 30 Apr 2018 19:53:47 +0100 (BST) Subject: [PATCH] ima: define a new policy condition based on the filesystem name From: Mimi Zohar To: linux-integrity Cc: linux-fsdevel@vger.kernel.org, linux-kernel , Dave Chinner , "Theodore Ts'o" Date: Mon, 30 Apr 2018 15:01:34 -0400 X-Mailer: Evolution 3.20.5 (3.20.5-1.fc24) Mime-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 18043019-0040-0000-0000-00000453916C X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18043019-0041-0000-0000-000020F7AA05 Message-Id: <1525114894.5669.5.camel@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-04-30_08:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=3 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1804300182 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 If/when file data signatures are distributed with the file data, this patch will not be needed. In the current environment where only some files are signed, the ability to differentiate between file systems is needed. Some file systems consider the file system magic number internal to the file system. This patch defines a new IMA policy condition named "fsname", based on the superblock's file_system_type (sb->s_type) name. This allows policy rules to be expressed in terms of the filesystem name. The following sample rules require file signatures on rootfs files executed or mmap'ed. appraise func=BPRM_CHECK fsname=rootfs appraise_type=imasig appraise func=FILE_MMAP fsname=rootfs appraise_type=imasig Signed-off-by: Mimi Zohar Cc: Dave Chinner Cc: Theodore Ts'o --- Documentation/ABI/testing/ima_policy | 2 +- security/integrity/ima/ima_policy.c | 25 ++++++++++++++++++++++++- 2 files changed, 25 insertions(+), 2 deletions(-) diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index b8465e00ba5f..74c6702de74e 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -21,7 +21,7 @@ Description: audit | hash | dont_hash condition:= base | lsm [option] base: [[func=] [mask=] [fsmagic=] [fsuuid=] [uid=] - [euid=] [fowner=]] + [euid=] [fowner=] [fsname=]] lsm: [[subj_user=] [subj_role=] [subj_type=] [obj_user=] [obj_role=] [obj_type=]] option: [[appraise_type=]] [permit_directio] diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index d89bebf85421..03cbba423e59 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -33,6 +33,7 @@ #define IMA_INMASK 0x0040 #define IMA_EUID 0x0080 #define IMA_PCR 0x0100 +#define IMA_FSNAME 0x0200 #define UNKNOWN 0 #define MEASURE 0x0001 /* same as IMA_MEASURE */ @@ -74,6 +75,7 @@ struct ima_rule_entry { void *args_p; /* audit value */ int type; /* audit type */ } lsm[MAX_LSM_RULES]; + char *fsname; }; /* @@ -273,6 +275,9 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode, if ((rule->flags & IMA_FSMAGIC) && rule->fsmagic != inode->i_sb->s_magic) return false; + if ((rule->flags & IMA_FSNAME) + && strcmp(rule->fsname, inode->i_sb->s_type->name)) + return false; if ((rule->flags & IMA_FSUUID) && !uuid_equal(&rule->fsuuid, &inode->i_sb->s_uuid)) return false; @@ -540,7 +545,7 @@ enum { Opt_audit, Opt_hash, Opt_dont_hash, Opt_obj_user, Opt_obj_role, Opt_obj_type, Opt_subj_user, Opt_subj_role, Opt_subj_type, - Opt_func, Opt_mask, Opt_fsmagic, + Opt_func, Opt_mask, Opt_fsmagic, Opt_fsname, Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq, Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt, Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt, @@ -565,6 +570,7 @@ static match_table_t policy_tokens = { {Opt_func, "func=%s"}, {Opt_mask, "mask=%s"}, {Opt_fsmagic, "fsmagic=%s"}, + {Opt_fsname, "fsname=%s"}, {Opt_fsuuid, "fsuuid=%s"}, {Opt_uid_eq, "uid=%s"}, {Opt_euid_eq, "euid=%s"}, @@ -776,6 +782,17 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) if (!result) entry->flags |= IMA_FSMAGIC; break; + case Opt_fsname: + ima_log_string(ab, "fsname", args[0].from); + + entry->fsname = kstrdup(args[0].from, GFP_KERNEL); + if (!entry->fsname) { + result = -ENOMEM; + break; + } + result = 0; + entry->flags |= IMA_FSNAME; + break; case Opt_fsuuid: ima_log_string(ab, "fsuuid", args[0].from); @@ -1104,6 +1121,12 @@ int ima_policy_show(struct seq_file *m, void *v) seq_puts(m, " "); } + if (entry->flags & IMA_FSNAME) { + snprintf(tbuf, sizeof(tbuf), "%s", entry->fsname); + seq_printf(m, pt(Opt_fsname), tbuf); + seq_puts(m, " "); + } + if (entry->flags & IMA_PCR) { snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr); seq_printf(m, pt(Opt_pcr), tbuf);