Re: [PATCH V2 1/4] selftests/sgx: Fix NULL-pointer-dereference upon early test failure

[Shuah Khan <skhan@linuxfoundation.org>]

On 2/2/22 11:52 AM, Reinette Chatre wrote:
> Hi Shuah and Dave,
> 
> On 2/2/2022 10:01 AM, Shuah Khan wrote:
>> On 2/1/22 3:47 PM, Reinette Chatre wrote:
>>> == Background ==
>>>
>>> The SGX selftests track parts of the enclave binaries in an array:
>>> encl->segment_tbl[]. That array is dynamically allocated early
>>> (but not first) in the test's lifetime. The array is referenced
>>> at the end of the test in encl_delete().
>>>
>>> == Problem ==
>>>
>>> encl->segment_tbl[] can be NULL if the test fails before its
>>> allocation. That leads to a NULL-pointer-dereference in encl_delete().
>>> This is triggered during early failures of the selftest like if the
>>> enclave binary ("test_encl.elf") is deleted.
>>>
>>> == Solution ==
>>>
>>
>> "==" usage looks a bit odd in the change log.
> 
> This is a new trend in the x86/ area and I was asked to modify the commit
> message to follow suit in:
> https://lore.kernel.org/linux-sgx/df2248d2-eb61-22d6-3a51-d8091f9eaad6@intel.com/
> 
> 

Good to know. Thanks for the link.

>>
>> The rest looks good to me. I can take this through kselftest tree, if not,
>>
>> Acked-by: Shuah Khan <skhan@linuxfoundation.org>
>>
> 
> Thank you very much for reviewing the changes.
> 
> None of the patches in this series have external dependencies (all patches
> in the "Fixes:" can be found in v5.17-rc1) but my understanding is that Dave
> (for now) prefers to take them via the tip.git tree. This is because there
> are more SGX features and tests for those features [1] in flight to the
> SGX area and at least for now it would make things easier if the changes to
> the SGX selftests are contained in the same tree.
> 
> Dave: please do correct me if I am wrong.
> 

Sounds good to me.

thanks,
-- Shuah