AMD ATI atillk64.sys - physical memory mapping driver: MULTI-TENANT ISOLATION: The AMD ATI atillk64.sys driver exposes

Impact

MULTI-TENANT ISOLATION: The AMD ATI atillk64.sys driver exposes routines that map physical memory into a caller's virtual address space, and it lets low-privileged users call them. That is arbitrary physical memory read and write handed to any local user - complete bypass of kernel memory protection with no memory-corruption exploit required, because the driver simply offers the capability. Drivers like this are a favourite BYOVD (bring-your-own-vulnerable-driver) primitive precisely because they are signed and they work as designed.

Who can reach it

Local, low-privileged user with the driver loaded. Windows driver; note that an attacker can also *bring* this driver to a host that never shipped it, which is why it matters even if you do not deploy AMD's Windows tooling.

What to do

Remove or update the driver. On Windows fleets, add atillk64.sys to your vulnerable-driver blocklist (Microsoft's WDAC blocklist covers this class) rather than relying on it not being installed - the BYOVD path means an attacker supplies the driver themselves. Not applicable to Linux ROCm nodes.

References