Comment by Arrath
4 years ago
We do read about occasional vulnerabilities on phone GPUs, but I do have to wonder. Wouldn't the compartmentalization and difference in compute abilities between CPU and GPU inherently limit the scope to which a vulnerability on the GPU in a typical PC can exploit?
Compartmentalization might make chaining the exploit more difficult, but it's certainly not unheard of. There have been exploit chains in the past that manage to jump from the baseband to the main CPU, for example.
One of my favorite exploits [0] was from Project Zero where the chain began with a vulnerability in the Apple wireless stack (Broadcom? maybe, but that might be a different exploit I'm thinking of), and ended in arbitrary kernel RCE. In other words, it was "a wormable radio-proximity exploit which allows me to gain complete control over any iPhone in my vicinity."
More relevantly to your question, here's a writeup about exploiting a GPU. [1]
[0] https://googleprojectzero.blogspot.com/2020/12/an-ios-zero-c...
[1] https://googleprojectzero.blogspot.com/2020/09/attacking-qua...
Thank you! Not my area but I do love reading about it.
Same... the people at Project Zero are basically magicians. I love reading their write-ups, even if I barely understand most of them.
Generally, no. Often you’ll see GPUs have extensive access to the system’s physical memory and vice versa which makes exploiting either processor from the other fairly common due to buggy drivers.