Re: [PATCH 0/3] userfaultfd: allow to forbid unprivileged users

Kees Cook
2019-03-15T16:09:45Z

On Thu, Mar 14, 2019 at 9:16 AM Andrea Arcangeli <aarcange@redhat.com> wrote:
> So this will be for who's paranoid and prefers to disable userfaultfd
> as a whole as an hardening feature like the bpf sysctl allows: it will
> allow to block uffd syscall without having to rebuild the kernel with
> CONFIG_USERFAULTFD=n in environments where seccomp cannot be easily
> enabled (i.e. without requiring userland changes).
>
> That's very fine with me, but then it wasn't me complaining in the
> first place. Kees?

I'm fine with a boolean. I just wanted to find a way to disable at
runtime (so distro users had it available to them).

--
Kees Cook