On Mon, Sep 09, 2013 at 04:30:31PM +0100, thegeezer wrote:
> >> i read in slashdot that there is a question mark over SELinux because it came
> >> from the NSA [4] but this is nonsense, as it is a means of securing processes
> >> not network connections.  i find it difficult to believe that a backdoor in a
> >> locked cupboard in your house can somehow give access through the front door.
> > This point you get wrong. SELinux implement the LSM API (in fact the LSM API
> > was tailored to SELinux needs). It has hooks in nearly everything
> > (file/directory access, process access and also sockets). One of the biggest
> > concerns at the time of creation of the LSM API was rootkits hooking that
> > functions. It's definitively a thread. I'm not saying that SELinux contains
> > a backdoor (I for myself would have hidden it in the LSM part, not in SELinux
> > because that would enable me to use it even if other LSMs are used). If you
> > google for "underhanded C contest" you'll see that it's possible to hide
> > malicious behaviour in plain sight. And if the kernel is compromised all other
> > defenses mean nothing. (As I said,  I don't want to spread fearbut that is
> > something to consider imho).
> Interesting, I didn't realise LSM provisioned hooks for SELinux -
> thought it it was more modular (and less 'shoehorned') than that. 
> I need to go read about that some more now


You can start here:

http://www.freetechbooks.com/efiles/selinuxnotebook/The_SELinux_Notebook_The_Foundations_3rd_Edition.pdf

for a general overview (page 64ff has a list of the hooks).
Other than that http://www.kroah.com/linux/talks/ols_2002_lsm_paper/lsm.pdf and
http://www.nsa.gov/research/_files/publications/implementing_selinux.pdf may be
of interest (though both are quite old).

WKR
Hinnerk