Re: [PATCH V31 07/25] kexec_file: Restrict at runtime if the kernel is locked down

From: Mimi Zohar
Date: Mon Jun 24 2019 - 21:46:27 EST


On Mon, 2019-06-24 at 17:02 -0700, Matthew Garrett wrote:
> On Mon, Jun 24, 2019 at 2:27 PM Mimi Zohar <zohar@xxxxxxxxxxxxx> wrote:
>
> > I agree with Dave. There should be a stub lockdown function to
> > prevent enforcing lockdown when it isn't enabled.
>
> Sorry, when what isn't enabled? If no LSMs are enforcing lockdown then
> the check will return 0. The goal here is for distributions to be able
> to ship a kernel that has CONFIG_KEXEC_SIG=y, CONFIG_KEXEC_SIG_FORCE=n
> and at runtime be able to enforce a policy that requires signatures on
> kexec payloads.

Never mind, the call can't be moved earlier.