Re: [cobalt-security] RAZOR advisory: Linux 2.2.xx /proc/<pid>/mem mmap() vulnerability

[Eugene Crosser <crosser@xxxxxxxxxxx>]

On Thu, 2002-12-19 at 20:12, David Seaton wrote:
> On a curious note.
> To my understanding, I can install RaQ4 or even RaQ 550 onto my RaQ3.
> However the 550 requires a bios upgrade, which if done wrong can leave your
> system permanently dead.
> So my questions are. How risky is it to upgrade, i.e. can it be done with
> relatively reliable or are my chances 50/50?

On this list, multiple people reported success, and I did not see any
failure reports.  Just read *carefully* the documentation that accompany
ROM image / flashing utility.

> And here's a good question..
> After the bios upgrade, can I still load the RaQ3 software back onto the
> machine?

I think that the answer is yes, but I never tried, and someone on this
list thinks that it is impossible to return back.

What is definitely true, is that you can reflash the old image back (if
your server boots, of course).

> ok, one more question, what exactly does this bios upgrade do? what is it fixing
> or changing?

Cobalt ROM image is very much unlike a traditional PC BIOS.  It knows
about the filesystem on the hard drive, and loads the kernel directly
from a file, without LILO magic.  Therefore, for instance, RaQ4 loader
that only knows about ext2 won't be able to read the kernel from XFS on
the hard disk of a 550.  Plus, Cobalt ROM includes a complete Linux
kernel which you can boot if the kernel image on the disk is damaged.

Eugene