From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8989CC433E6 for ; Wed, 30 Dec 2020 01:09:06 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 172FB21D1B for ; Wed, 30 Dec 2020 01:09:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 172FB21D1B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=linux-audit-bounces@redhat.com Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-174-lvNMHf7xNOCa7FPWQ16p9g-1; Tue, 29 Dec 2020 20:09:03 -0500 X-MC-Unique: lvNMHf7xNOCa7FPWQ16p9g-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5540F800D53; Wed, 30 Dec 2020 01:09:00 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3C33D1001281; Wed, 30 Dec 2020 01:09:00 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 16C165002C; Wed, 30 Dec 2020 01:08:42 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 0BTJGuO7000772 for ; Tue, 29 Dec 2020 14:16:56 -0500 Received: by smtp.corp.redhat.com (Postfix) id DC36A1002972; Tue, 29 Dec 2020 19:16:55 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast05.extmail.prod.ext.rdu2.redhat.com [10.11.55.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D7C2F1111C89 for ; Tue, 29 Dec 2020 19:16:53 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A9D92800883 for ; Tue, 29 Dec 2020 19:16:53 +0000 (UTC) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-69-XVm98MLjOc6rH47IReYO5Q-1; Tue, 29 Dec 2020 14:16:51 -0500 X-MC-Unique: XVm98MLjOc6rH47IReYO5Q-1 Received: from pps.filterd (m0098416.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 0BTJ1Xj1102758 for ; Tue, 29 Dec 2020 14:16:50 -0500 Received: from pps.reinject (localhost [127.0.0.1]) by mx0b-001b2d01.pphosted.com with ESMTP id 35r9h613bg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 29 Dec 2020 14:16:50 -0500 Received: from m0098416.ppops.net (m0098416.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 0BTJDWg9152743 for ; Tue, 29 Dec 2020 14:16:50 -0500 Received: from ppma03fra.de.ibm.com (6b.4a.5195.ip4.static.sl-reverse.com [149.81.74.107]) by mx0b-001b2d01.pphosted.com with ESMTP id 35r9h613b1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 29 Dec 2020 14:16:49 -0500 Received: from pps.filterd (ppma03fra.de.ibm.com [127.0.0.1]) by ppma03fra.de.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 0BTJDfRL011467; Tue, 29 Dec 2020 19:16:48 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma03fra.de.ibm.com with ESMTP id 35nvt89ns7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 29 Dec 2020 19:16:47 +0000 Received: from d06av22.portsmouth.uk.ibm.com (d06av22.portsmouth.uk.ibm.com [9.149.105.58]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 0BTJGhJr29295046 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 29 Dec 2020 19:16:43 GMT Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9A1884C040; Tue, 29 Dec 2020 19:16:45 +0000 (GMT) Received: from d06av22.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D21C04C046; Tue, 29 Dec 2020 19:16:42 +0000 (GMT) Received: from sig-9-65-200-189.ibm.com (unknown [9.65.200.189]) by d06av22.portsmouth.uk.ibm.com (Postfix) with ESMTP; Tue, 29 Dec 2020 19:16:42 +0000 (GMT) Message-ID: Subject: Re: [PATCH v23 02/23] LSM: Create and manage the lsmblob data structure. From: Mimi Zohar To: Casey Schaufler , casey.schaufler@intel.com, jmorris@namei.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Date: Tue, 29 Dec 2020 14:16:41 -0500 In-Reply-To: <10442dd5-f16e-3ca4-c233-7394a11cbbad@schaufler-ca.com> References: <20201120201507.11993-1-casey@schaufler-ca.com> <20201120201507.11993-3-casey@schaufler-ca.com> <886fcd04-6a08-d78c-dc82-301c991e5ad8@schaufler-ca.com> <07784164969d0c31debd9defaedb46d89409ad78.camel@linux.ibm.com> <8f11964c-fa7e-21d1-ea60-7d918cfaabe0@schaufler-ca.com> <10442dd5-f16e-3ca4-c233-7394a11cbbad@schaufler-ca.com> Mime-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.343, 18.0.737 definitions=2020-12-29_13:2020-12-28, 2020-12-29 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 lowpriorityscore=0 adultscore=0 clxscore=1015 priorityscore=1501 phishscore=0 malwarescore=0 suspectscore=0 spamscore=0 bulkscore=0 mlxlogscore=999 mlxscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012290117 X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-loop: linux-audit@redhat.com X-Mailman-Approved-At: Tue, 29 Dec 2020 20:07:45 -0500 Cc: john.johansen@canonical.com, linux-kernel@vger.kernel.org, linux-audit@redhat.com, bpf@vger.kernel.org, sds@tycho.nsa.gov X-BeenThere: linux-audit@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Linux Audit Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-audit-bounces@redhat.com Errors-To: linux-audit-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=linux-audit-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Tue, 2020-12-29 at 10:46 -0800, Casey Schaufler wrote: > >>>>>> -int security_audit_rule_match(u32 secid, u32 field, u32 op, void *lsmrule) > >>>>>> +int security_audit_rule_match(u32 secid, u32 field, u32 op, void **lsmrule) > >>>>>> { > >>>>>> - return call_int_hook(audit_rule_match, 0, secid, field, op, lsmrule); > >>>>>> + struct security_hook_list *hp; > >>>>>> + int rc; > >>>>>> + > >>>>>> + hlist_for_each_entry(hp, &security_hook_heads.audit_rule_match, list) { > >>>>>> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) > >>>>>> + continue; > >>>>>> + rc = hp->hook.audit_rule_match(secid, field, op, > >>>>>> + &lsmrule[hp->lsmid->slot]); > >>>>>> + if (rc) > >>>>>> + return rc; > >>>>> Suppose that there is an IMA dont_measure or dont_appraise rule, if one > >>>>> LSM matches, then this returns true, causing any measurement or > >>>>> integrity verification to be skipped. > >>>> Yes, that is correct. Like the audit system, you're doing a string based > >>>> lookup, which pretty well has to work this way. I have proposed compound > >>>> label specifications in the past, but even if we accepted something like > >>>> "apparmor=dates,selinux=figs" we'd still have to be compatible with the > >>>> old style inputs. > >>>> > >>>>> Sample policy rules: > >>>>> dont_measure obj_type=foo_log > >>>>> dont_appraise obj_type=foo_log > >>> IMA could extend the existing policy rules like "lsm=[selinux] | > >>> [smack] | [apparmor]", but that assumes that the underlying > >>> infrastructure supports it. > >> Yes, but you would still need rational behavior in the > >> case where someone has old IMA policy rules. > > From an IMA perspective, allowing multiple LSMs to define the same > > policy label is worse than requiring the label be constrained to a > > particular LSM. > > Just to be sure we're talking about the same thing, > the case I'm referring to is something like a file with > two extended attributes: > > security.apparmor MacAndCheese > security.SMACK64 MacAndCheese > > and an IMA rule that says > > dont_measure obj_type=MacAndCheese > > In this case the dont_measure will be applied to both. > On the other hand, > > security.apparmor MacAndCheese > security.SMACK64 FranksAndBeans > > would also apply the rule to both, which is not > what you want. Unfortunately, there is no way to > differentiate which LSM hit the rule. > > So now I'm a little confused. The case where both LSMs > use the same label looks like it works right, where the > case where they're different doesn't. I'm more concerned about multiple LSMs using the same label. The label's meaning is LSM specific. > > I'm beginning to think that identifying which LSMs matched > a rule (it may be none, either or both) is the right solution. > I don't think that audit is as sensitive to this. If the label's meaning is LSM specific, then the rule needs to be LSM specific. -- Linux-audit mailing list Linux-audit@redhat.com https://www.redhat.com/mailman/listinfo/linux-audit