Re: [PATCH v4 2/2] selftests: tpm2: Reset the dictionary attack lock

[Stefan Berger]

On 11/29/21 18:43, Jarkko Sakkinen wrote:
> On Sat, Nov 27, 2021 at 11:10:52PM -0500, Stefan Berger wrote:
> > From: Stefan Berger <stefanb@xxxxxxxxxxxxx>
> >
> > Reset the dictionary attack lock to avoid the following types of test
> > failures after running the test 2 times:
> >
> > ======================================================================
> > ERROR: test_unseal_with_wrong_policy (tpm2_tests.SmokeTest)
> > ----------------------------------------------------------------------
> > Traceback (most recent call last):
> >    File "/root/linux-ima-namespaces/tools/testing/selftests/tpm2/tpm2_tests.py", line 105, in test_unseal_with_wrong_policy
> >      blob = self.client.seal(self.root_key, data, auth, policy_dig)
> >    File "/root/linux-ima-namespaces/tools/testing/selftests/tpm2/tpm2.py", line 620, in seal
> >      rsp = self.send_cmd(cmd)
> >    File "/root/linux-ima-namespaces/tools/testing/selftests/tpm2/tpm2.py", line 397, in send_cmd
> >      raise ProtocolError(cc, rc)
> > tpm2.ProtocolError: TPM_RC_LOCKOUT: cc=0x00000153, rc=0x00000921
> >
> > Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
> > ---
> >   tools/testing/selftests/tpm2/tpm2_tests.py | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/tools/testing/selftests/tpm2/tpm2_tests.py b/tools/testing/selftests/tpm2/tpm2_tests.py
> > index e63a37819978..ad6f54c01adf 100644
> > --- a/tools/testing/selftests/tpm2/tpm2_tests.py
> > +++ b/tools/testing/selftests/tpm2/tpm2_tests.py
> > @@ -139,6 +139,8 @@ class SmokeTest(unittest.TestCase):
> >           except:
> >               self.client.flush_context(handle)
> >               raise
> > +        finally:
> > +            self.client.reset_da_lock()
> >   
> >           self.assertEqual(rc, tpm2.TPM2_RC_POLICY_FAIL)
> >   
> > --
> > 2.31.1
> I don't agree with this as a DA lock has legit use. This would be adequate
> for systems dedicated for kernel testing only.

The problem is this particular test case I am patching here causes the 
above test failures upon rerun. We are testing the driver here 
presumably and not the TPM2, so I think we should leave the TPM2 as 
cleaned up as possible, thus my suggestion is to reset the DA lock and 
we won't hear any complaints after that.


> We could make this available in the folder where TPM2 tests are:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/tpm2-scripts.git/tree/tpm2-reset-da-lock


The tss packages also have command line tools to reset the DA lock, but 
it shouldn't be necessary to use them after running a **driver** test case.


   stefan


> /Jarkko