Re: [PATCH] dns: fix heap corruption

[Andrei Borzenkov]

11.07.2016 09:02, Michael Chang пишет:
> On Fri, Jul 08, 2016 at 10:54:37PM +0300, Andrei Borzenkov wrote:
>> 07.07.2016 12:18, Michael Chang пишет:
>>> Since commit f9d1b4422efb2c06e5472fb2c304712e2029796b I occasionally bumped
>>> into heap corruption problem during dns lookup.
>>>
>>> After tracing the issue, it looks the *data->addresses array is not 
>>> correctly
>>> allocated. It need to hold accumulated dns look up result but not only the 
>>> new
>>> result in new message. The heap corruption occured when appending new 
>>> result to
>>> it.
>>>
>>> This patch fixed the issue for me by reallocating the array if it found too
>>> small to hold all the result. 
>>>
>>
>> I'm not sure. I think we discussed this with Josef back then. The code
>> apparently was assuming single response; and if we are going to collect
>> multiple answers, we need to filter out duplicates at least and also not
>> depend on packet order to select between A and AAAA.
> 
> OK.
> 
>>
>> Does attached patch fix corruption for you? I think that is the least
>> intrusive as bug fix, and we need to revisit code to properly handle
>> multiple responses later.
> 
> Yes, it does. I have tested several times to make sure it doesn't happen.
> 
> Thanks for review.
> 

Applied. Thanks!