[PATCH v5 6/7] tpm: ensure that the output of PCR read contains the correct digest size

[Jarkko Sakkinen]

On Fri, Nov 16, 2018 at 05:06:48PM +0100, Roberto Sassu wrote:
> On 11/16/2018 2:41 PM, Jarkko Sakkinen wrote:
> > On Wed, Nov 14, 2018 at 04:31:07PM +0100, Roberto Sassu wrote:
> > > This patch protects against data corruption that could happen in the bus,
> > > by checking that that the digest size returned by the TPM during a PCR read
> > > matches the size of the algorithm passed to tpm2_pcr_read().
> > > 
> > > This check is performed after information about the PCR banks has been
> > > retrieved.
> > > 
> > > Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
> > > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen at linux.intel.com>
> > > Cc: stable at vger.kernel.org
> > 
> > Missing fixes tag.
> 
> Before this patch set, tpm2_pcr_extend() always copied 20 bytes from the
> output sent by the TPM.
> 
> Roberto

Aah, right, of course. Well the patch set is ATM somewhat broken because
this would require a fixes tag that points to a patch insdie the patch
set.

Probably good way to fix the issue is to just merge this with the
earlier commit.

/Jarkko