Re: [dpdk-dev] [PATCH] security: fix crash at accessing non-implemented ops

[Lukasz Wojciechowski <l.wojciechow@partner.samsung.com>]

W dniu 23.04.2020 o 09:54, Ananyev, Konstantin pisze:
>> Hi Konstantin,
>>
>> These are data path ops and so it will be better if we can avoid such checks in the datapath. The same is done in ethdev also.
> AFAIK,  get_userdata is an *optional* dev-ops function that can be used by data-path.
> So far there was no strict requirement for the rte_security PMDs to *always* implement it.
> So what you guys did is a silent change of public API behaviour.
> As result ixgbe, (and probably some others rte_security PMDs) stopped working properly.
> I don't see any point in these changes, but if you'd like to do that, at
> least our usual procedure has to be followed:
> 1. Send and RFC to get an agreement with rte_security PMDs maintainers (one release ahead)
> 2. send a deprecation note (one release ahead)
> 3. change the behaviour of the public API
> 4. update release notes
>
> AFAIK 1), 2), 4) wasn't done.
> So I think right now we need to revert original behaviour.
The current changes were made in patch: b6ee9854784 security: fix 
verification of parameters

<snip>
@@ -91,7 +119,9 @@ rte_security_get_userdata(struct rte_security_ctx 
*instance, uint64_t md)
  {
         void *userdata = NULL;

- RTE_FUNC_PTR_OR_ERR_RET(*instance->ops->get_userdata, NULL);
+#ifdef RTE_DEBUG
+       RTE_PTR_CHAIN3_OR_ERR_RET(instance, ops, get_userdata, NULL, NULL);
+#endif
         if (instance->ops->get_userdata(instance->device, md, &userdata))
                 return NULL;
  <snip>


So as you can see, the checks were already there. They've just been 
wrapped up with RTE_DEBUG macro for disabling them in non-debug 
compilation mode and the validation of paramter was change to avoid 
possible segmentation fault if instance lub ops would be NULL

>> https://protect2.fireeye.com/url?k=e0478418-bdd92a82-e0460f57-0cc47a336fae-55cc35a7b94c97c0&q=1&u=http%3A%2F%2Fcode.dpdk.org%2Fdpdk%2Fv20.02%2Fsource%2Flib%2Flibrte_ethdev%2Frte_ethdev.h%23L4372
>>
>> Datapath functions in cryptodev (enqueue/dequeue) doesn't even have such checks.
>> https://protect2.fireeye.com/url?k=79d7974a-244939d0-79d61c05-0cc47a336fae-19f540008a9467cf&q=1&u=http%3A%2F%2Fcode.dpdk.org%2Fdpdk%2Fv20.02%2Fsource%2Flib%2Flibrte_cryptodev%2Frte_cryptodev.h%23L962
> That's a different story:
> rx_burst/tx_burst, enqueue/dequeue are mandatory dev-ops functions that
> have to be implemented by each  ethdev/cryptodev API.
>
>>
>> Thanks,
>> Anoob
>>
>>> -----Original Message-----
>>> From: dev <dev-bounces@dpdk.org> On Behalf Of Konstantin Ananyev
>>> Sent: Thursday, April 23, 2020 5:22 AM
>>> To: dev@dpdk.org
>>> Cc: akhil.goyal@nxp.com; declan.doherty@intel.com; Konstantin Ananyev
>>> <konstantin.ananyev@intel.com>
>>> Subject: [dpdk-dev] [PATCH] security: fix crash at accessing non-implemented
>>> ops
>>>
>>> Valid checks for optional function pointers inside dev-ops were disabled by
>>> undefined macro.
>>>
>>> Fixes: b6ee98547847 ("security: fix verification of parameters")
>>>
>>> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
>>> ---
>>>   lib/librte_security/rte_security.c | 4 ----
>>>   1 file changed, 4 deletions(-)
>>>
>>> diff --git a/lib/librte_security/rte_security.c b/lib/librte_security/rte_security.c
>>> index d475b0977..b65430ce2 100644
>>> --- a/lib/librte_security/rte_security.c
>>> +++ b/lib/librte_security/rte_security.c
>>> @@ -107,11 +107,9 @@ rte_security_set_pkt_metadata(struct rte_security_ctx
>>> *instance,
>>>   			      struct rte_security_session *sess,
>>>   			      struct rte_mbuf *m, void *params)  { -#ifdef
>>> RTE_DEBUG
>>>   	RTE_PTR_CHAIN3_OR_ERR_RET(instance, ops, set_pkt_metadata, -
>>> EINVAL,
>>>   			-ENOTSUP);
>>>   	RTE_PTR_OR_ERR_RET(sess, -EINVAL);
>>> -#endif
>>>   	return instance->ops->set_pkt_metadata(instance->device,
>>>   					       sess, m, params);
>>>   }
>>> @@ -121,9 +119,7 @@ rte_security_get_userdata(struct rte_security_ctx
>>> *instance, uint64_t md)  {
>>>   	void *userdata = NULL;
>>>
>>> -#ifdef RTE_DEBUG
>>>   	RTE_PTR_CHAIN3_OR_ERR_RET(instance, ops, get_userdata, NULL,
>>> NULL); -#endif
>>>   	if (instance->ops->get_userdata(instance->device, md, &userdata))
>>>   		return NULL;
>>>
>>> --
>>> 2.17.1
>
-- 

Lukasz Wojciechowski
Principal Software Engineer

Samsung R&D Institute Poland
Samsung Electronics
Office +48 22 377 88 25
l.wojciechow@partner.samsung.com