Re: [dpdk-dev] [PATCH v4 05/19] vhost: fix error handling when mem table gets updated

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 10/09/2018 01:35 PM, Tiwei Bie wrote:
> On Mon, Oct 08, 2018 at 05:25:43PM +0200, Maxime Coquelin wrote:
>> When the memory table gets updated, the rings addresses need
>> to be translated again. If it fails, we need to exit cleanly
>> by unmapping memory regions.
>>
>> Fixes: d5022533c20a ("vhost: retranslate vring addr when memory table changes")
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Acked-by: Ilya Maximets <i.maximets@samsung.com>
>> ---
>>   lib/librte_vhost/vhost_user.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
>> index 71a0e7dd7..3f01926e2 100644
>> --- a/lib/librte_vhost/vhost_user.c
>> +++ b/lib/librte_vhost/vhost_user.c
>> @@ -964,7 +964,7 @@ vhost_user_set_mem_table(struct virtio_net **pdev, struct VhostUserMsg *msg)
>>   
>>   			dev = translate_ring_addresses(dev, i);
>>   			if (!dev)
>> -				return VH_RESULT_ERR;
>> +				goto err_mmap;
> 
> When dev is NULL, we can't just goto err_mmap directly,
> otherwise we will dereference the NULL pointer.

Indeed, thanks for catching it.
I think we should restore dev to *pdev value.

>>   
>>   			*pdev = dev;
>>   		}
>> -- 
>> 2.17.1
>>