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

[Stefan Berger <stefanb@linux.ibm.com>]

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@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.

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