Re: [PATCH] Revert "tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()"

[Nayna]

Hi Tyler,


On 07/04/2019 03:58 PM, Tyler Hicks wrote:
> Hey Mimi!
>
> On 2019-07-04 11:46:41, Mimi Zohar wrote:
> > Hi Jarkko,
> >
> > On Thu, 2019-07-04 at 07:48 -0400, Mimi Zohar wrote:
> > > On Thu, 2019-07-04 at 13:28 +0200, Roberto Sassu wrote:
> > > > On 7/4/2019 12:03 PM, Jarkko Sakkinen wrote:
> > > > > On Mon, 2019-07-01 at 15:15 +0200, Michal Suchanek wrote:
> > > > > > This reverts commit 0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400 to avoid
> > > > > > following crash:
> > > > > Thank you. I think this the right choice for the moment. I fixed
> > > > > a trivial checkpatch.pl error and added the mandatory tags. Can
> > > > > you check quickly v2 (just posted)?
> > > > >
> > > > > I already made it available in my master and next.
> > > > Could you please wait few days? I would prefer to fix this issue instead
> > > > of reverting the whole patch.
> > > Nayna posted a patch late yesterday titled "tpm: fixes uninitialized
> > > allocated banks for IBM vtpm driver", which addresses this bug.
> > Now with my review, and with Sachin Sant's and Michal SuchÃnek
> > testing, instead of reverting this patch could you pick up Nayna's
> > patch instead?
> It looks to me like the revert would also fix a bug that is keeping the
> eCryptfs module from loading when the TPM is in an "inactive" state:
>
>    https://bugzilla.kernel.org/show_bug.cgi?id=203953
>
> I just noticed that it was recently discussed here, too:
>
>    https://lore.kernel.org/linux-integrity/1562244125.6165.95.camel@xxxxxxxxxxxxx/T/#t
>
> I believe that the revert would fix it because the call to
> init_digests()/tpm_get_random() would no longer be in the path of
> loading ecryptfs.ko (which depends on encrypted-keys.ko, which depends
> on trusted.ko).
>
> If the revert isn't used, we'll need a different fix for bug 203953. It
> should be an easy fix but I don't want it to be forgotten.


I think if TPM is inactive/disabled, it needs to be handled during 
tpm_chip_register() itself. However, probably that needs more analysis 
and discussion. For now, in context of the trusted.ko module, it seems 
init_trusted() should "put_device", but continue even if init_digests() 
fails, that will fix the issue.


Thanks & Regards,
ÂÂÂÂÂÂÂ - Nayna