[FFmpeg-devel] [PATCH] vp9: don't retain NULL as segmentation_map

[Andreas Cadhalpun]

On 18.06.2015 23:43, Ronald S. Bultje wrote:
> OK, looked further, it's actually quite complicated and I don't think
> it's easy to do "the correct thing". The reason is that on frame header
> error, we don't move the reference frame state forward (that's the code
> in vp9_decode_frame right after reading the frame header), so all kind
> of things get in a weird state. Your patch should probably go in, it
> doesn't "fix" the weird state (i.e. I'm not convinced it's technically
> "correct") but at least it's not "bad" (crash-causing), just "weird"
> (technically possibly wrong, but it already was so that's ok).
> 
> To do the correct thing, I should probably implement error resilience,
> it's not exactly easy so I'll leave that for sometime later.

Thanks for this analysis. I've pushed the patch now.

By the way, afl [1] is really a great tool for finding such problems.
I can only recommend everyone to try it out yourself.

Best regards,
Andreas

1: http://lcamtuf.coredump.cx/afl/