Re: [RFC PATCH for 4.18 12/23] cpu_opv: Provide cpu_opv system call (v7)

[Linus Torvalds]

On Fri, Apr 13, 2018 at 5:16 AM, Mathieu Desnoyers
<mathieu.desnoyers@xxxxxxxxxxxx> wrote:
> The vmalloc space needed by cpu_opv is bound by the number of pages
> a cpu_opv call can touch.

No it's not.

You can have a thousand different processes doing cpu_opv at the same time.

A *single* cpu_opv may me limited toi "only" a megabyte, but I'm not
seeing any global limit anywhere.

In short, this looks like a guaranteed DoS approach to me.

                   Linus