Received: by 2002:ac0:a594:0:0:0:0:0 with SMTP id m20-v6csp4753160imm; Fri, 18 May 2018 10:04:08 -0700 (PDT) X-Google-Smtp-Source: AB8JxZoITlUJWXcN4vFvNTB7X009ngM1iQFqa7nv9bTUY1bmlZ2xbjwgepUgGIXAKpgz30tR2ryT X-Received: by 2002:a63:9711:: with SMTP id n17-v6mr8298127pge.431.1526663048222; Fri, 18 May 2018 10:04:08 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1526663048; cv=none; d=google.com; s=arc-20160816; b=OphmqrtBC2o2x51Mju3mTewAnimMgqRX9iNjRy5MGeFzb/HHYTJ1k9l2uNUF4NtrMp bZNXo10vbgnEeZZKQxcG/5XtUv1A5gvxGN/VA5WaoC8dBja2jQU+RQQ7kMPhewy5mmJY 6FGzmTTPzgOV/cbbVkZioQYst3eqS+TmltuhXu5Ll74wDPxwciTJqMYnoPn0XtejfRDM NC9k7NQF9N4iyCw8YxwZcIUzKT00kTvkwz92rBXFJCCcRcQYrhBoepcwIMVeFuPnhcZ/ xl36h9a7zdkEmpiLAjtFPMCaxcsk/EM9Nk+S+phxbf2cffk7/lWYGeQSg8K7Cwh6ohLQ pwxA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:in-reply-to :content-transfer-encoding:content-disposition:mime-version :references:message-id:subject:cc:to:from:date :arc-authentication-results; bh=07PSN0aj3/vcRDno3LKzHHSNJATyQKNoY+Qw7lPNkZ8=; b=ePYPlTkJy0tappA/72QhqNMBUJq/O3Z1nkAGUenzcJjZQK2UkRuyJipgjd6fKZylMu 58evUoaIIYe1wxO5FE0JkD1TbT1R6vBPiB/++AEuWDdYPgC0lOdD7RYZKTwuFf4CTfcM Fsvr+K55odLzNGb0CiQ5yf/wk75iih61s8suueK+WchOhVGL+CLY9vGBH7TyMEN/n6TP L69wcExRebTaHgdk7BjTwswN1PotRkqdv43Qp5uwOJ8hI4fDmfKU3wtGe/8e/Unh3h8m 05YDgvHl7nqrul62uB6s6kymWAgwWeRvotxuFvLA+ulgZjh25t3skcbdMzwsdS4gXNON POFw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id e11-v6si5925066pgf.469.2018.05.18.10.03.47; Fri, 18 May 2018 10:04:08 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752552AbeERRC1 (ORCPT + 99 others); Fri, 18 May 2018 13:02:27 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:36526 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752348AbeERRCX (ORCPT ); Fri, 18 May 2018 13:02:23 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D5C8D805A531; Fri, 18 May 2018 17:02:22 +0000 (UTC) Received: from madcap2.tricolour.ca (ovpn-112-24.rdu2.redhat.com [10.10.112.24]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E318B2026E03; Fri, 18 May 2018 17:02:20 +0000 (UTC) Date: Fri, 18 May 2018 13:01:46 -0400 From: Richard Guy Briggs To: Stefan Berger Cc: Mimi Zohar , containers@lists.linux-foundation.org, Linux-Audit Mailing List , linux-integrity , LKML , paul@paul-moore.com, sgrubb@redhat.com Subject: Re: [PATCH] audit: add containerid support for IMA-audit Message-ID: <20180518170146.56u7krqfj7hxu55r@madcap2.tricolour.ca> References: <1520257393.10396.291.camel@linux.vnet.ibm.com> <20180305135008.po6lheqnmkqqo6q4@madcap2.tricolour.ca> <1520259854.10396.313.camel@linux.vnet.ibm.com> <20180308112104.z67wohdvjqemy7wy@madcap2.tricolour.ca> <20180517213001.62caslkjwv575xgl@madcap2.tricolour.ca> <86df5c2c-9db3-21b9-b91b-30a4f53f9504@linux.vnet.ibm.com> <20180518154553.dy53m3os7aql3urd@madcap2.tricolour.ca> <7fdca0e0-19d5-1f08-8aa2-f295ad3a86de@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7fdca0e0-19d5-1f08-8aa2-f295ad3a86de@linux.vnet.ibm.com> User-Agent: NeoMutt/20171027 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Fri, 18 May 2018 17:02:22 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Fri, 18 May 2018 17:02:22 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'rgb@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-05-18 12:49, Stefan Berger wrote: > On 05/18/2018 11:45 AM, Richard Guy Briggs wrote: > > On 2018-05-18 07:49, Stefan Berger wrote: > > > On 05/17/2018 05:30 PM, Richard Guy Briggs wrote: > > > > On 2018-05-17 10:18, Stefan Berger wrote: > > > > > On 03/08/2018 06:21 AM, Richard Guy Briggs wrote: > > > > > > On 2018-03-05 09:24, Mimi Zohar wrote: > > > > > > > On Mon, 2018-03-05 at 08:50 -0500, Richard Guy Briggs wrote: > > > > > > > > On 2018-03-05 08:43, Mimi Zohar wrote: > > > > > > > > > Hi Richard, > > > > > > > > > > > > > > > > > > This patch has been compiled, but not runtime tested. > > > > > > > > Ok, great, thank you. I assume you are offering this patch to be > > > > > > > > included in this patchset? > > > > > > > Yes, thank you. > > > > > > > > > > > > > > > I'll have a look to see where it fits in the > > > > > > > > IMA record. It might be better if it were an AUDIT_CONTAINER_INFO > > > > > > > > auxiliary record, but I'll have a look at the circumstances of the > > > > > > > > event. > > > > > > I had a look at the context of this record to see if adding the contid > > > > > > field to it made sense. I think the only records for which the contid > > > > > > field makes sense are the two newly proposed records, AUDIT_CONTAINER > > > > > > which introduces the container ID and the and AUDIT_CONTAINER_INFO which > > > > > > documents the presence of the container ID in a process event (or > > > > > > process-less network event). All others should use the auxiliary record > > > > > > AUDIT_CONTAINER_INFO rather than include the contid field directly > > > > > > itself. There are several reasons for this including record length, the > > > > > > ability to filter unwanted records, the difficulty of changing the order > > > > > > of or removing fields in the future. > > > > > > > > > > > > Syscalls get this information automatically if the container ID is set > > > > > > for a task via the AUDIT_CONTAINER_INFO auxiliary record. Generally a > > > > > > syscall event is one that uses the task's audit_context while a > > > > > > standalone event uses NULL or builds a local audit_context that is > > > > > > discarded immediately after the local use. > > > > > > > > > > > > Looking at the two cases of AUDIT_INTEGRITY_RULE record generation, it > > > > > > appears that they should be split into two distinct audit record types. > > > > > > > > > > > > The record created in ima_audit_measurement() is a syscall record that > > > > > > could possibly stand on its own since the subject attributes are > > > > > > present. If it remains a syscall auxiliary record it will automatically > > > > > > have the AUDIT_CONTAINER_INFO record accompany it anyways. If it is > > > > > > decided to detach it (which would save cpu/netlink/disk bandwidth but is > > > > > > not recommended due to not wanting to throw away any other syscall > > > > > > information or other involved records (PATH, CWD, etc...) then a local > > > > > > audit_context would be created for the AUDIT_INTEGRITY_RULE and > > > > > > AUDIT_CONTAINERID_INFO records only and immediately discarded. > > > > > What does 'detach it' mean? Does it mean we're not using > > > > > current->audit_context? > > > > Exactly. > > > > > > > > > > The record created in ima_parse_rule() is not currently a syscall record > > > > > > since it is passed an audit_context of NULL and it has a very different > > > > > > format that does not include any subject attributes (except subj_*=). > > > > > > At first glance it appears this one should be a syscall accompanied > > > > > > auxiliary record. Either way it should have an AUDIT_CONTAINER_INFO > > > > > Do you have an example (pointer) to the format for a 'syscall accompanied > > > > > auxiliary record'? > > > > Any that uses current->audit_context (or recently proposed > > > > audit_context() function) will be a syscall auxiliary record. Well > > > > formed record formats are = and named as listed: > > > > > > > > https://github.com/linux-audit/audit-documentation/wiki/SPEC-Writing-Good-Events > > > > https://github.com/linux-audit/audit-documentation/blob/master/specs/fields/field-dictionary.csv > > > > > > > > > > auxiliary record either by being converted to a syscall auxiliary record > > > > > > by using current->audit_context rather than NULL when calling > > > > > > audit_log_start(), or creating a local audit_context and calling > > > > > ima_parse_rule() is invoked when setting a policy by writing it into > > > > > /sys/kernel/security/ima/policy. We unfortunately don't have the > > > > > current->audit_context in this case. > > > > Sure you do. What process writes to that file? That's the one we care > > > > about, unless it is somehow handed off to a queue and processed later in > > > > a different context. > > > I just printk'd it again. current->audit_context is NULL in this case. > > Oops, that sounds like some of the netfilter empty table > > initializations, whereas usually rules have a user actor. > > So it's a bug elsewhere not a 'feature?' Er, it is a challenge we're aware of and have already solved a number of them. What happens if you boot with "audit=1" on the kernel command line? > > > > > > audit_log_container_info() then releasing the local context. This > > > > > > version of the record has additional concerns covered here: > > > > > > https://github.com/linux-audit/audit-kernel/issues/52 > > > > > Following the discussion there and the concern with breaking user space, how > > > > > can we split up the AUDIT_INTEGRITY_RULE that is used in > > > > > ima_audit_measurement() and ima_parse_rule(), without 'breaking user space'? > > > > Arguably userspace is already broken by this wildly diverging pair of > > > > formats for the same record. > > > > > > > > > A message produced by ima_parse_rule() looks like this here: > > > > > > > > > > type=INTEGRITY_RULE msg=audit(1526566213.870:305): action="dont_measure" > > > > > fsmagic="0x9fa0" res=1 > > > > > > > > > > in contrast to that an INTEGRITY_PCR record type: > > > > > > > > > > type=INTEGRITY_PCR msg=audit(1526566235.193:334): pid=1615 uid=0 auid=0 > > > > > ses=2 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 > > > > > op="invalid_pcr" cause="open_writers" comm="scp" > > > > > name="/var/log/audit/audit.log" dev="dm-0" ino=1962625 res=1 > > > > > > > > > > Should some of the fields from INTEGRITY_PCR also appear in INTEGRITY_RULE? > > > > Not necessarily. There are a number of records in the PCR record that > > > > would be redundant when connected to a syscall record, but removing them > > > > is discouraged to avoid breaking parsers that expect them. > > > > > > > > I don't see any need to touch the PCR record. > > > I wasn't going to touch the PCR record. > > > > > > > > > > > If so, which ones? We could probably refactor the current > > > > > integrity_audit_message() and have ima_parse_rule() call into it to get > > > > > those fields as well. I suppose adding new fields to it wouldn't be > > > > > considered breaking user space? > > > > Changing the order of existing fields or inserting fields could break > > > > stuff and is strongly discouraged without a good reason, but appending > > > > fields is usually the right way to add information. > > > > > > > > There are exceptions, and in this case, I'd pick the "more standard" of > > > > the formats for AUDIT_INTEGRITY_RULE (ima_audit_measurement?) and stick > > > > with that, abandoning the other format, renaming the less standard > > > > version of the record (ima_parse_rule?) and perhpas adopting that > > > > abandonned format for the new record type while using > > > > current->audit_context. > > > Since current->audit_context is NULL I built on your patch, but I am not > > > sure whether it is justifyable to use that before your container id series > > > is applied. > > > > > > This is what ima_parse_rule() produces now after having it call > > > audit_log_task_info() as well and by introducing 1806 for ima_parse_rule() > > > only ( https://lkml.org/lkml/2018/5/11/386 ): > > > > > > type=UNKNOWN[1806] msg=audit(1526643702.328:304): action="dont_measure" > > > fsmagic="0x9fa0" res=1 ppid=1563 pid=1595 auid=0 uid=0 gid=0 euid=0 suid=0 > > > fsuid=0 egid=0 sgid=0 fsgid=0 tty=tty2 ses=2 comm="cat" exe="/usr/bin/cat" > > > subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 > > > > > > [before: type=INTEGRITY_RULE msg=audit(1526566213.870:305): > > > action="dont_measure" fsmagic="0x9fa0" res=1] > > Since this appears to be a a user action, use current->audit_context > > to make it a syscall auxiliary record rather than adding all these > > redundant fields. > > Sure, once we have a non-NULL pointer in current->audit_context I'd do that. > > > > > > For comparison the INTEGRITY_RULE: > > > > > > type=INTEGRITY_RULE msg=audit(1526642504.074:331): file="/usr/bin/ssh" hash="sha256:4abc2558424b9ca61c34af43169d9b9e174d7825bf60c9c76be377549081db5b" > > > ppid=1623 pid=1624 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 > > > fsgid=0 tty=tty2 ses=2 comm="scp" exe="/usr/bin/scp" > > > subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 > > > > > > > > > 1806 would be in sync with INTEGRITY_RULE now for process related info. If > > > this looks good, I'll remove the dependency on your local context creation > > > and post the series. > > What would be the macro name for 1806? > > I currently work with AUDIT_INTEGRITY_POLICY_RULE. > > > > > > > The justification for the change is that the INTEGRITY_RULE, as produced by > > > ima_parse_rule(), is broken. > > > > > > ??? Stefan > > > > > > > > > > Does this help? > > > > > > > > > ??? Stefan > > > > > > > > > > > Can you briefly describe the circumstances under which these two > > > > > > different identically-numbered records are produced as a first step > > > > > > towards splitting them into two distict records? > > > > > > > > > > > > The four AUDIT_INTEGRITY _METADATA, _PCR, _DATA and _STATUS records > > > > > > appear to be already properly covered for AUDIT_CONTAINER_INFO records > > > > > > by being syscall auxiliary records. The AUDIT_INTEGRITY_HASH record > > > > > > appears to be unused. > > > > > > > > > > > > > > Can you suggest a procedure to test it? > > > > > > > Like IMA-measurement and IMA-appraisal, IMA-audit is enabled based on > > > > > > > policy. The example IMA policy, below, includes IMA-audit messages for > > > > > > > files executed. 'cat' the policy to /sys/kernel/security/ima/policy. > > > > > > > > > > > > > > /etc/ima/ima-policy: > > > > > > > audit func=BPRM_CHECK > > > > > > > > > > > > > > There's a FireEye blog titled "Extending Linux Executable Logging With > > > > > > > The Integrity Measurement Architecture"* that explains how to augment > > > > > > > their existing system security analytics with file hashes. > > > > > > > > > > > > > > *?https://www.fireeye.com/blog/threat-research/2016/11/extending_linux > > > > > > > _exec.html > > > > > > > > > > > > > > > > > > > > > Mimi > > > > > > > > > > > > > > > > If the containerid is defined, include it in the IMA-audit record. > > > > > > > > > > > > > > > > > > Signed-off-by: Mimi Zohar > > > > > > > > > --- > > > > > > > > > security/integrity/ima/ima_api.c | 3 +++ > > > > > > > > > 1 file changed, 3 insertions(+) > > > > > > > > > > > > > > > > > > diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c > > > > > > > > > index 33b4458cdbef..41d29a06f28f 100644 > > > > > > > > > --- a/security/integrity/ima/ima_api.c > > > > > > > > > +++ b/security/integrity/ima/ima_api.c > > > > > > > > > @@ -335,6 +335,9 @@ void ima_audit_measurement(struct integrity_iint_cache *iint, > > > > > > > > > audit_log_untrustedstring(ab, algo_hash); > > > > > > > > > audit_log_task_info(ab, current); > > > > > > > > > + if (audit_containerid_set(current)) > > > > > > > > > + audit_log_format(ab, " contid=%llu", > > > > > > > > > + audit_get_containerid(current)); > > > > > > > > > audit_log_end(ab); > > > > > > > > > iint->flags |= IMA_AUDITED; > > > > > > > > > -- > > > > > > > > > 2.7.5 > > > > > > > > > > > > > > > > > - RGB > > > > > > - RGB > > > > > > > > > > > > -- > > > > > > Richard Guy Briggs > > > > > > Sr. S/W Engineer, Kernel Security, Base Operating Systems > > > > > > Remote, Ottawa, Red Hat Canada > > > > > > IRC: rgb, SunRaycer > > > > > > Voice: +1.647.777.2635, Internal: (81) 32635 > > > > > > > > > > - RGB > > > > > > > > -- > > > > Richard Guy Briggs > > > > Sr. S/W Engineer, Kernel Security, Base Operating Systems > > > > Remote, Ottawa, Red Hat Canada > > > > IRC: rgb, SunRaycer > > > > Voice: +1.647.777.2635, Internal: (81) 32635 > > > > > > - RGB > > > > -- > > Richard Guy Briggs > > Sr. S/W Engineer, Kernel Security, Base Operating Systems > > Remote, Ottawa, Red Hat Canada > > IRC: rgb, SunRaycer > > Voice: +1.647.777.2635, Internal: (81) 32635 > > > - RGB -- Richard Guy Briggs Sr. S/W Engineer, Kernel Security, Base Operating Systems Remote, Ottawa, Red Hat Canada IRC: rgb, SunRaycer Voice: +1.647.777.2635, Internal: (81) 32635