[FFmpeg-devel] [PATCH] Unbreak av_malloc_max(0) API/ABI

James Almer jamrial at gmail.com
Tue Oct 13 20:03:43 EEST 2020

On 10/13/2020 11:24 AM, Derek Buitenhuis wrote:
> On 13/10/2020 15:19, Joakim Tjernlund wrote:
>> For now just fixing av_malloc_max(0) will do, av_max_malloc2() etc. is beyond this patch.
> As Ronald mentioned, if you're going to fix the ABI/API, you should actually
> fix every use of that ABI/API, not just the one you care about (0).
> So max values of 1-31 should also be handled.

I personally don't think there's anything to fix, or if there is, it's
not this. For starters av_max_alloc() was never changed. It was how
av_malloc() handled the max_alloc_size variable. And then, the old
behavior was both buggy (0 to 31 equaling SIZE_MAX or slightly smaller)
and undocumented. I could accept reverting it for the 4.3 branch for the
sake of ABI compatibility, but after a sobump 0-31 should not wrap
around or be replaced by something arbitrary like INT_MAX.

Chromium already fixed their code by requesting a SIZE_MAX limit
(meaning effectively unlimited), which is what they wanted to begin
with, and others should follow.

> - Derek
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".

More information about the ffmpeg-devel mailing list