[FFmpeg-devel] [PATCH 1/2] MxPEG decoder

[Anatoly Nenashev]

On 29.11.2010 20:51, Anatoly Nenashev wrote:
> On 29.11.2010 16:12, Anatoly Nenashev wrote:
>> On 25.11.2010 18:26, Michael Niedermayer wrote:
>>> On Mon, Nov 08, 2010 at 01:40:39PM +0300, Anatoly Nenashev wrote:
>>>> [...]
>>>> I think I've found a solution for this issue. If input packet doesn't
>>>> contain SOF data then the new picture is allocated from
>>>> reference_picture which is initiated at decode_frame end. Thus
>>>> reference_picture is always good. For more details see attachment.
>>>
>>> the issue i described has not been fixed
>>> a invalid SOF still can lead to inconsistant values and your code 
>>> still naively
>>> sets got_picture=1 indicating a valid SOF even if that is not so.
>>>
>>> Fundamentally i think the problem is that you write the code while 
>>> ignoring
>>> security aspects entirely and expect review to find security issues.
>>> You should make sure your code is secure and no crafted input no 
>>> matter how
>>> evil and malformed can lead to any crash or exploit before you 
>>> submit your
>>> code.
>>>
>>>
>>> [...]
>>>
>>
>> I've reimplemented decoder to be more secure. There is additional 
>> flag named "got_sof_data" which shows that SOF data is succesfully 
>> parsed.
>> Also ugly picture reallocation removed.
>>
> Add dimensions check for current and reference picture.
> Patch tested under valgrind and on trashed stream.


Ping. Please review this patch.