Re: net/ipv6: potential deadlock in do_ipv6_setsockopt

[Baozeng Ding <sploving1@gmail.com>]

It fixes the issue for me. 
Tested-by: Baozeng Ding <sploving1@gmail.com>

On 2016/10/17 17:54, Baozeng Ding wrote:
> Applied the patch to my test tree. I will tell you the result a few days later. Thank you.
> 
> On 2016/10/17 2:50, Cong Wang wrote:
>> On Sun, Oct 16, 2016 at 6:34 AM, Baozeng Ding <sploving1@gmail.com> wrote:
>>>  Possible unsafe locking scenario:
>>>
>>>        CPU0                    CPU1
>>>        ----                    ----
>>>   lock([  165.136033] sk_lock-AF_INET6
>>> );
>>>                                lock([  165.136033] rtnl_mutex
>>> );
>>>                                lock([  165.136033] sk_lock-AF_INET6
>>> );
>>>   lock([  165.136033] rtnl_mutex
>>> );
>>>
>>>  *** DEADLOCK ***
>>
>> This is caused by the conditional rtnl locking in do_ipv6_setsockopt().
>> It looks like we miss the case of IPV6_ADDRFORM.
>>
>> Please try the attached patch.
>>