Re: [PATCH] IMA: Turn IMA_MEASURE_ASYMMETRIC_KEYS off by default

From: Mimi Zohar
Date: Wed Jan 22 2020 - 15:03:09 EST


On Tue, 2020-01-21 at 12:38 -0800, Lakshmi Ramasubramanian wrote:
> On 1/21/2020 11:52 AM, James Bottomley wrote:
>
> >> - really small devices/sensors being able to queue certificates
> >
> > seems like the answer to this one would be don't queue. I realise it's
> > after the submit design, but what about measuring when the key is added
> > if there's a policy otherwise measure the keyring when the policy is
> > added ... that way no queueing.
>
> Without the "deferred key processing" changes, only keys added at
> runtime were measured (if policy permitted).
>
> "deferred key processing" enabled queuing keys added early in the boot
> process and measured them when the policy is loaded.
>
> We can make this (the queuing) optional through a config, but leave the
> runtime key measurement auto-enabled (as is the config
> IMA_MEASURE_ASYMMETRIC_KEYS now).

Thanks, Lakshmi. ÂThis requires moving the code around. ÂInstead of
doing this on the current code base, I suggest posting a v9 version of
the entire "IMA: Deferred measurement of keys".

I suggest making the switch from spinlock to mutex, as you had it
originally, before posting v9. ÂThe commit history will then be a lot
cleaner.

thanks,

Mimi