Re: [PATCH 00/35] Shadow stacks for userspace

Cyrill Gorcunov
2022-02-08T09:29:32Z

On Tue, Feb 08, 2022 at 11:16:51AM +0200, Mike Rapoport wrote:
>
> > Any thoughts on how you would _like_ to see this resolved?
>
> Ideally, CRIU will need a knob that will tell the kernel/CET machinery
> where the next RET will jump, along the lines of
> restore_signal_shadow_stack() AFAIU.
>
> But such a knob will immediately reduce the security value of the entire
> thing, and I don't have good ideas how to deal with it :(

Probably a kind of latch in the task_struct which would trigger off once
returt to a different address happened, thus we would be able to jump inside
paratite code. Of course such trigger should be available under proper
capability only.