On Tue, May 16, 2006 at 11:27:00AM +0200, Joachim Schipper wrote:
> On Tue, May 16, 2006 at 03:26:39PM +1000, Steffen Kluge wrote:
> > On Sat, 2006-05-13 at 16:18 +0200, Ed White wrote:
> > > It seems XFree people disagree...
> > > [...]
> > > ...and some Linux developers too...
> > >
> > > Alan Cox: What it essentially says is "if you can hack the machine enough
> > > to
> > > get the ability to issue raw i/o accesses you can get any other power you
> > > want". Thats always been true. Using SMM to do this seems awfully hard
> > > work.
> >
> > He said that in reply to you saying:
> >
> > > The big problem is that the attack is possible thanks to the way X
> > > Windows is designed
> >
> > He didn't comment on whether X is flawed or not, but rather that from a
> > Linux perspective this whole issue is a storm in a tea cup. In
> > (distribution default) Linux it is always possible for root to get ring
> > 0 access. Simply because root can load kernel modules. That's what root
> > kits do. Fumbling registers through a hacked X server is a novel but
> > rather complicated way, in comparison.
> >
> > Hence, securing a Linux server has always meant (besides removing X and
> > tons of other crud) to build a kernel that doesn't support loadable
> > modules.
>
> And adding something to ensure that /dev/*mem cannot be written by root.
> There exist pre-written rootkits which load directly via /dev/mem, IIRC.
>
> Of course, simply disabling loadable modules does do some good...
and this is related to openbsd how?
cu
--
paranoic mickey (my employers have changed but, the name has remained)
