Re: [Ksummit-2013-discuss] [ARM ATTEND] catching up on exploitmitigations

From: Dave Jones
Date: Wed Aug 21 2013 - 11:44:48 EST


On Wed, Aug 21, 2013 at 04:26:14PM +0100, Russell King - ARM Linux wrote:
> On Wed, Jul 31, 2013 at 10:24:30AM -0400, Dave Jones wrote:
> > On Wed, Jul 31, 2013 at 10:40:12AM +0100, Russell King - ARM Linux wrote:
> > > On Tue, Jul 30, 2013 at 08:04:44PM -0400, Dave Jones wrote:
> > > > To use ARM as an example, the bugs I've seen have mostly been in arch specific
> > > > code that does things like page-table manipulation. The chromebook bugs I
> > > > was hitting for eg were various kinds of PTE corruption warnings.
> > >
> > > Hmm, really? Did you reported these bugs? I'm not aware of mainline
> > > having any changes related to bug reports on PTEs on ARM.
> >
> > I wasn't sure if it was a googleism, or happens on mainline, so no.
>
> I've been running several iterations of it for a while (== up to 10 minutes
> run time - which is normally about how long it takes to find the rather-too-
> exposed kmalloc in sys_oabi_epoll_wait) and so far have seen no sign of any
> page table corruption.

awesome. Guess it was a google specific issue then.
(Or something that got fixed post 3.4)

> Maybe you can give some ideas as to how you were running it? Was it
> running as root or as a normal user?

yeah, unpriv'd user.

> Were there any nonstandard platform
> specific devices in /dev which that user could access - such as graphics
> or video decoder devices which could be exposing big holes?

I'm not sure what google patched into that kernel altogether, so who knows..

Dave

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