Re: Google hacks Zen 2 to 4 microcode

On Fri, 18 Apr 2025 21:48:19 +0000, Thomas Koenig wrote:

The microcode of the Zen 2 to Zen 4 processors has been hacked by
security people from Google:
>
https://bughunters.google.com/blog/5424842357473280/zen-and-the-art-of-microcode-hacking
>
Apart from breaking getting updates past  AMD's signature
verificiation process, they also created a toolbox for
playing around with the microcode.  There is also quite
some information on the internal microcode format at
https://github.com/google/security-research/blob/master/pocs/cpus/entrysign/zentool/

I was an architect at AMD when we put microcode patching in the chips.
We did understand that the encryption and keys were not sufficiently
strong at that instant in time, and there were other driving factors.
But, I am surprised that it took this long to break (~22 years).