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

[David Howells]

Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> wrote:

> Right, it would never get here if the IMA signature verification
> fails. ÂIf sig_enforce is not enabled, then it will also work. ÂSo the
> only case is if sig_enforced is enabled and there is no key.
> 
> eg.
> Â Â Â Â Âelse if (can_do_ima_check && is_ima_appraise_enabled())
> Â Â Â Â Â Â Â Â err = 0;

I'm not sure where you want to put that, but I can't just do this:

	/* Not having a signature is only an error if we're strict. */
	if (err == -ENOKEY && !sig_enforce &&
	    (!can_do_ima_check || !is_ima_appraise_enabled()) &&
	    !kernel_is_locked_down("Loading of unsigned modules"))
		err = 0;
	else if (can_do_ima_check && is_ima_appraise_enabled())
		err = 0;

because that'll print out a message in lockdown mode saying that you're not
allowed to do that and then maybe do it anyway.

David