Re: [PATCH 4/7] firmware_class: perform new LSM checks

Mimi Zohar
2014-07-21T02:50:22Z

On Mon, 2014-07-21 at 09:43 +1000, James Morris wrote:
> On Sat, 19 Jul 2014, Kees Cook wrote:
>
> [...]
>
> > With the patch series, the LSM hook sees the userspace-touching loads:
> > - from kernel built-in: no LSM hook (nonsense to check the static list)
> > - direct from filesystem: called with file struct
> > - via uevent /sys "loading"/"data" interface: called with NULL file struct
> > - via uevent /sys "fd" interface: called with file struct
>
> Thanks for the overview. Can we get this documented in the LSM code?
>
> > The reason the "fd" interface was added was because otherwise there's
> > no way for systems that use the uevent handler to communicate to the
> > kernel where the bytes being shoved into the "data" interface are
> > coming from.
>
> Ok.
>
> I gather folks have also thought about signing firmware?

>From an IMA perspective, this would be the same as for any other file,
just a new hook.

Mimi