Re: [PATCH 0/4] KEYS: validate key trust with owner and builtin keys only

Matthew Garrett
2014-06-10T21:25:29Z

On Wed, Jun 11, 2014 at 12:17:53AM +0300, Dmitry Kasatkin wrote:

> It is probably just a paranoia...
> Kconfig MODULE_SIG_UEFI should tell about threat of loading kernel
> modules from NSA or Lenovo signed by MS or Lenovo keys..
>
> This hole is opened without warning...

It's not typically a hole. If an attacker has root they can just replace
your bootloader with one signed by a trusted key and then have that
modify the kernel before booting it.

If you're using a TPM then you can mitigate this, but if you have a TPM
then you're already performing some extra steps during the boot process.
Just add a sysfs knob that lets you drop the db keys and incorporate
that into the TPM management code.

--
Matthew Garrett | mjg59@srcf.ucam.org