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

[Jarkko Sakkinen <jarkko@kernel.org>]

On Sat, Nov 27, 2021 at 11:10:52PM -0500, Stefan Berger wrote:
> From: Stefan Berger <stefanb@linux.ibm.com>
> 
> 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@linux.ibm.com>
> ---
>  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.

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

/Jarkko