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

Dmitry Kasatkin
2014-06-10T13:22:05Z

On 10/06/14 15:52, Mimi Zohar wrote:
> On Tue, 2014-06-10 at 08:20 -0400, Josh Boyer wrote:
>> On Tue, Jun 10, 2014 at 11:48:14AM +0300, Dmitry Kasatkin wrote:
>>> Also I want to discuss here Fedora UEFI patches as they are the reason for
>>> the these original patchset.
>>>
>>> http://pkgs.fedoraproject.org/cgit/kernel.git/tree/modsign-uefi.patch
>>>
>>> They provide functionality to specify MokIgnoreDb variable to limit loading of
>>> UEFI keys only from MOK List, while ignoring DB. This is certainly a good
>>> functionality. But once MODULE_SIG_UEFI is enabled, it looks there is no way
>>> to prevent loading keys from UEFI at all. And this might not be a good default
>>> functionality. Someone might want not allow loading of keys from UEFI unless
>>> kernel parameter is specified to allow it without recompiling the kernel
>>> and disabling MODULE_SIG_UEFI.
>>>
>>> Josh, why such design decision was made?
>> IIRC, it's because kernel parameters can be added programmatically from a
>> remote user if they gain root access. Having a kernel parameter to
>> disable a key piece of secure boot isn't all that great. We disable
>> other kernel parameters like acpi_rspd as well.
> In this case, there shouldn't be a problem as the kernel parameters
> would further limit the keys usage.
>
> Mimi

Josh probably means that it can be removed and restriction is lifted..
And after reboot, all keys come to the keyring..

>