Re: [PATCH] tpm: vtpm_proxy: Do not access host's event log

From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Stefan Berger <stefanb@linux.vnet.ibm.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>,
	tpmdd-devel@lists.sourceforge.net, nayna@linux.vnet.ibm.com,
	linux-security-module@vger.kernel.org
Subject: Re: [PATCH] tpm: vtpm_proxy: Do not access host's event log
Date: Thu, 17 Nov 2016 15:43:20 -0800	[thread overview]
Message-ID: <20161117234320.bla4cvabblnfxgth@intel.com> (raw)
In-Reply-To: <513da75c-6221-39ce-2718-19290c216ff1@linux.vnet.ibm.com>

On Thu, Nov 17, 2016 at 06:15:20PM -0500, Stefan Berger wrote:
> On 11/17/2016 01:33 PM, Jason Gunthorpe wrote:
> > On Thu, Nov 17, 2016 at 01:25:54PM -0500, Stefan Berger wrote:
> > > In the case of x86, tpm_read_log_of() is a stub return -ENODEV, which in
> > > turn fails the whole device:
> > Somehow this got screwed up during the lengthy review. ENODEV is the
> > right return from the leaf routines but the tests in tpm_eventlog di
> > not get fixed:
> > 
> > > http://git.infradead.org/users/jjs/linux-tpmdd.git/blob/4d388433e85f8257f5a9344a7acf6f499ba2b29e:/drivers/char/tpm/tpm_eventlog.h#l87
> > Is wrong, should be:
> > 
> > if (rc != -ENODEV)
> >     return rc;
> > 
> > And the one in tpm_bios_log_setup should be
> > 
> > if (rc != 0 && rc != -ENODEV)
> >      return rc;
> 
> 
> Can you show a patch that shows where to place these two?

The disasterous error handling for cases that you mentioned:

http://git.infradead.org/users/jjs/linux-tpmdd.git/commitdiff/d660a91a1b9dd80f5c2c973e3369400d3c9f9848

I'm sorry I let these slip in the code review.

/Jarkko