Re: [PATCH 03/27] Enforce module signatures if the kernel is locked down

From: Mimi Zohar
Date: Mon Oct 30 2017 - 13:52:32 EST


[Corrected Matthew Garrett's email address. ÂCc'ed Bruno Meneguele]

On Mon, 2017-10-30 at 17:00 +0000, David Howells wrote:
> Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> wrote:
>
> > This kernel_is_locked_down() check is being called for both the
> > original and new module_load syscalls. ÂWe need to be able
> > differentiate them. ÂThis is fine for the original syscall, but for
> > the new syscall we would need an additional IMA check -
> > !is_ima_appraise_enabled().
>
> IMA can only be used with finit_module()?

Yes, without the file descriptor, IMA-appraisal can't access the
xattrs.Â

You should really look at Bruno's patches, which are in my next
branch:

8168913c50d5 "ima: check signature enforcement against cmdline param instead of CONFIG"
404090509894 module: export module signature enforcement status

Can we get an Ack on the module one?

Mimi