[FFmpeg-devel] [PATCH 1/3] Revert "avcodec: Add max_pixels options"

[Andreas Cadhalpun]

On 11.12.2016 19:27, Nicolas George wrote:
> Le primidi 21 frimaire, an CCXXV, Michael Niedermayer a écrit :
>> Fuzzers search and find issues like out of array accesses but also
>> hangs and oom conditions.
>> Fuzzers find hangs and OOM conditions by executing code until it runs
>> out of memory or reaches a timeout.
>> These cases are then reported and need to be checked by a human (that
>> being me in practice it seems)
>> ATM almost all of reported issues are false positives, going through
>> them takes significant amounts of time. the max_pixels parameter should
>> fix this as all the cases i looked at where hitting out of memory or
>> timeout because of very high resolutions.
> 
> Then run the fuzzers with a low address space limit. Problem solved.

No, that doesn't solve the problem. It takes much more time until the
address space limit is reached than checking the resolution before
starting to allocate the memory. And setting the memory limit too low
means that actually interesting cases can't be tested.

Also without options to eliminate common and in general unavoidable
slowness it becomes much harder to find real hangs among the many
false positives.

Best regards,
Andreas