Re: [Qemu-devel] [RFC] sanitize memory on system reset

[Peter Lieven]

On 13.06.2013 12:55, Markus Armbruster wrote:
> Peter Lieven <address@hidden> writes:
>
> > On 13.06.2013 10:40, Stefan Hajnoczi wrote:
> > > On Thu, Jun 13, 2013 at 08:09:09AM +0200, Peter Lieven wrote:
> > > > I was thinking if it would be a good idea to zeroize all memory
> > > > resources on system reset and
> > > > madvise dontneed them afterwards. This would avoid system reset
> > > > attacks in case the attacker
> > > > has only access to the console of a vServer but not on the physical
> > > > host and it would shrink
> > > > RSS size of the vServer siginificantly.
> > > I wonder if you'll hit weird OS installers or PXE clients that rely on
> > > stashing stuff in memory across reset.
> > One point:
> > Wouldn't a memory test which some systems do at startup break these as well?
> Systems that distinguish between warm and cold boot (such as PCs)
> generally run POST only on cold boot.
>
> I'm not saying triggering warm reboot and expecting memory contents to
> survive is a good idea, but it has been done.
so you would vote for not touching it or at least enable it only through
a cmdline paramter?

Peter