Re: [v2] RANDOM: ATH9K RNG delivers zero bits of entropy

From: Stephan Mueller
Date: Tue Sep 27 2016 - 11:17:22 EST


Am Dienstag, 27. September 2016, 16:44:16 CEST schrieb Kalle Valo:

Hi Kalle,

> Stephan Mueller <smueller@xxxxxxxxxx> wrote:
> > The ATH9K driver implements an RNG which is completely bypassing the
> > standard Linux HW generator logic.
> >
> > The RNG may or may not deliver entropy. Considering the conservative
> > approach in treating entropy with respect to non-auditable sources, this
> > patch changes the delivered entropy value to zero. The RNG still feeds
> > data into the input_pool but it is assumed to have no entropy.
> >
> > When the ATH9K RNG changes to use the HW RNG framework, it may re-enable
> > the entropy estimation considering that a user can change that value at
> > boot and runtime.
> >
> > Reviewed-by: Jason Cooper <jason@xxxxxxxxxxxxxx>
> > Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>
>
> Based on the discussion I'm dropping this patch. But the discussion was
> hard to follow so please let me know if I misunderstood.

I guess the rejection is appropriate, but something needs to be done:
add_hwgenerator_randomness should not be used in this scenario.
>
> Patch set to Rejected.



Ciao
Stephan