[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20071008185304.GA17671@sergelap.austin.ibm.com>
Date: Mon, 8 Oct 2007 13:53:04 -0500
From: "Serge E. Hallyn" <serue@...ibm.com>
To: "Eric W. Biederman" <ebiederm@...ssion.com>
Cc: casey@...aufler-ca.com, Stephen Smalley <sds@...ho.nsa.gov>,
Kyle Moffett <mrmacman_g4@....com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Bill Davidsen <davidsen@....com>,
James Morris <jmorris@...ei.org>,
Andrew Morton <akpm@...ux-foundation.org>,
linux-security-module@...r.kernel.org,
linux-kernel@...r.kernel.org, "Serge E. Hallyn" <serge@...lyn.com>
Subject: Re: [PATCH] Version 3 (2.6.23-rc8) Smack: Simplified Mandatory
Access Control Kernel
Quoting Eric W. Biederman (ebiederm@...ssion.com):
> Casey Schaufler <casey@...aufler-ca.com> writes:
>
> > --- "Eric W. Biederman" <ebiederm@...ssion.com> wrote:
> >
> >
> >> Likely. Until we have a generalized LSM interface with 1000 config
> >> options like netfilter I don't expect we will have grounds to talk
> >> or agree to a common user space interface. Although I could be
> >> wrong.
> >
> > Gulp. I know that many of you are granularity advocates, but I
> > have to say that security derived by tweeking 1000 knobs so that
> > they are all just right seems a little far fetched to me. I see
> > it as poopooing the 3rd and most important part of the reference
> > monitor concept, "small enough to analyze". Sure, you can analyse
> > the 1000 individual checks, but you'll never be able to describe
> > the system behavior as a whole.
>
> Agreed. I wasn't thinking 1000 individual checks but 1000 different
> capabilities, could be either checks or actions, basically fundamental
> different capabilities. Things like CIPSO, or the ability to store a
> security label on a file. I would not expect most security policies
> to use most of them. Neither do I expect Orange book security to
> necessarily be what people want to achieve with the LSM. But I
> haven't looked at it enough detail to know how things should be
> factored, in this case I was simply extrapolating from the iptables
> experience where we do have a very large number of options.
>
> The real point being is that I would be surprised if we could come
> to an agreement of a common user space API when we can't agree on how
> to compile all of the security modules into the kernel and have them
> play nice with each other.
>
> Assuming we can achieve security modules playing nice with each other
> using a mechanism similar to iptables, then what needs to be evaluated
> is the specific table configuration we are using on the system, not
> the full general set of possibilities. Further I expect that for the
> truly security paranoid we want the option to disable further table
> changes after the tables have been configured.
>
> On another side personally I don't see where the idea comes from that
> you can describe system behavior as a whole without analyzing the
> entire kernel. Has there been work on a sparse like tool that I'm
> not aware of to ensure the we always perform the appropriate security
> checks on the user/kernel interface boundary?
Yup, see the top of http://www.research.ibm.com/vali/
Pretty cool work that really should be continued.
-serge
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists