From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nikolay Aleksandrov <nikolay@redhat.com>
Subject: Re: [PATCH -net] netpoll: fix NULL pointer dereference in netpoll_cleanup
Date: Wed, 18 Sep 2013 23:06:57 +0200
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References: <1379427155-8561-1-git-send-email-nikolay@redhat.com> <20130918.121539.1213515779326200577.davem@davemloft.net>
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Cc: netdev@vger.kernel.org
To: David Miller <davem@davemloft.net>
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On 09/18/2013 06:15 PM, David Miller wrote:
> From: Nikolay Aleksandrov <nikolay@redhat.com>
> Date: Tue, 17 Sep 2013 16:12:35 +0200
> 
>> @@ -1284,15 +1284,15 @@ EXPORT_SYMBOL_GPL(__netpoll_free_async);
>>  
>>  void netpoll_cleanup(struct netpoll *np)
>>  {
>> -	if (!np->dev)
>> -		return;
>> -
>>  	rtnl_lock();
>> +	if (!np->dev) {
>> +		rtnl_unlock();
>> +		return;
>> +	}
>>  	__netpoll_cleanup(np);
>> -	rtnl_unlock();
>> -
>>  	dev_put(np->dev);
>>  	np->dev = NULL;
>> +	rtnl_unlock();
>>  }
>>  EXPORT_SYMBOL(netpoll_cleanup);
> 
> I know it seems arbitrary, but please do this like:
> 
> 	lock();
> 	if (condition) {
> 		...
> 	}
> 	unlock();
> 
> rather than having multiple return/unlock code paths.
> 
> This style I am suggesting is easier to audit for locking problems.
> 
> Thanks.
> 
Got it, I'll edit it and re-post.

Thanks,
 Nik