Re: RFC(v2): Audit Kernel Container IDs

From: Paul Moore <paul@paul-moore.com>
To: Aleksa Sarai <asarai@suse.de>,
	"Eric W. Biederman" <ebiederm@xmission.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>,
	cgroups@vger.kernel.org, mszeredi@redhat.com,
	Andy Lutomirski <luto@kernel.org>,
	jlayton@redhat.com, "Carlos O'Donell" <carlos@redhat.com>,
	API <linux-api@vger.kernel.org>,
	Linux Containers <containers@lists.linux-foundation.org>,
	Linux Kernel <linux-kernel@vger.kernel.org>,
	Viro <viro@zeniv.linux.org.uk>,
	David Howells <dhowells@redhat.com>,
	Linux FS Devel <linux-fsdevel@vger.kernel.org>,
	linux-audit@redhat.com, Simo Sorce <simo@redhat.com>,
	Development <netdev@vger.kernel.org>,
	Casey Schaufler <casey@schaufler-ca.com>,
	Eric Paris <eparis@parisplace.org>,
	Steve Grubb <sgrubb@redhat.com>,
	trondmy@primarydata.com
Subject: Re: RFC(v2): Audit Kernel Container IDs
Date: Thu, 19 Oct 2017 11:36:39 -0400	[thread overview]
Message-ID: <CAHC9VhTYF-MJm3ejWXE1H-eeXKaNBkeWKwdiKdj093xATYn7nQ@mail.gmail.com> (raw)
In-Reply-To: <871sm0j7bm.fsf@xmission.com>

On Wed, Oct 18, 2017 at 8:43 PM, Eric W. Biederman
<ebiederm@xmission.com> wrote:
> Aleksa Sarai <asarai@suse.de> writes:
>>>> The security implications are that anything that can change the label
>>>> could also hide itself and its doings from the audit system and thus
>>>> would be used as a means to evade detection.  I actually think this
>>>> means the label should be write once (once you've set it, you can't
>>>> change it) ...
>>>
>>> Richard and I have talked about a write once approach, but the
>>> thinking was that you may want to allow a nested container
>>> orchestrator (Why? I don't know, but people always want to do the
>>> craziest things.) and a write-once policy makes that impossible.  If
>>> we punt on the nested orchestrator, I believe we can seriously think
>>> about a write-once policy to simplify things.
>>
>> Nested containers are a very widely used use-case (see LXC system containers,
>> inside of which people run other container runtimes). So I would definitely
>> consider it something that "needs to be supported in some way". While the LXC
>> guys might be a *tad* crazy, the use-case isn't. :P

No worries, we're all a little crazy in our own special ways ;)

Kidding aside, thanks for explaining the use case.

> Of course some of that gets to running auditd inside a container which
> we don't have yet either.
>
> So I think to start it is perfectly fine to figure out the non-nested
> case first and what makes sense there.  Then to sort out the nested
> container case.
>
> The solution might be that a process gets at most one id per ``audit
> namespace''.

In an attempt to stay on-topic, let's try to stick with "audit
container ID" or "container ID" if you must.  I really want to avoid
the term "audit namespace" simply because the term "namespace" implies
some things which we aren't planning on doing.

-- 
paul moore
www.paul-moore.com