Re: [PATCH 0/6] Memory Mapping (VMA) protection using PKU - set 1

Dave Hansen
2023-05-15T14:28:35Z

On 5/15/23 06:05, jeffxu@chromium.org wrote:
> We're using PKU for in-process isolation to enforce control-flow integrity
> for a JIT compiler. In our threat model, an attacker exploits a
> vulnerability and has arbitrary read/write access to the whole process
> space concurrently to other threads being executed. This attacker can
> manipulate some arguments to syscalls from some threads.

This all sounds like it hinges on the contents of PKRU in the attacker
thread.

Could you talk a bit about how the attacker is prevented from running
WRPKRU, XRSTOR or compelling the kernel to write to PKRU like at sigreturn?