Re: [PATCH] KEYS: trusted: allow module init if TPM is inactive or deactivated

From: Tyler Hicks
Date: Mon Aug 05 2019 - 12:05:09 EST


On 2019-08-05 11:54:19, Mimi Zohar wrote:
> On Mon, 2019-08-05 at 16:50 +0200, Roberto Sassu wrote:
> > Regarding Mimi's proposal to avoid the issue by extending the PCR with
> > zeros, I think it also achieve the goal.
>
> Roberto, removing the following code from init_digests() would be the
> equivalent to the prior code, without needing to make any other
> changes.  Let's keep it simple.  Do you want to post the patch with
> the change, or should I?
>
> ret = tpm_get_random(chip, digest, TPM_MAX_DIGEST_SIZE);
> if (ret < 0)
> return ret;
> if (ret < TPM_MAX_DIGEST_SIZE)
> return -EFAULT;
>
> As I can't duplicate the problem, it would need to be tested by others
> experiencing the problem.

The bug reporter tested Roberto's last patch:

https://bugzilla.kernel.org/show_bug.cgi?id=203953#c8

We should Cc the reporter on future patches or at least leave another
testing request in the bugzilla.

Tyler

>
> thanks,
>
> Mimi
>