[FFmpeg-devel] [PATCH 05/14] avcodec/ffv1dec: Fix data races emanating from copying whole context

[Michael Niedermayer]

On Sat, Apr 24, 2021 at 01:14:37PM +0200, Andreas Rheinhardt wrote:
> When using frame threading, the FFV1 decoder's update_thread_context()
> function copies the whole context and afterwards restores some allocated
> fields with backups made earlier. Among these fields are the
> ThreadFrames and the source context's ThreadFrames can change
> concurrently without any synchronization, leading to data races which
> are undefined behaviour even if they don't lead to problems in
> practice (as the destination's own ThreadFrames are restored directly
> thereafter).
> 
> Fix this by only copying the actually needed fields.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
>  libavcodec/ffv1dec.c | 19 ++++++-------------
>  1 file changed, 6 insertions(+), 13 deletions(-)

LGTM

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The misfortune of the wise is better than the prosperity of the fool.
-- Epicurus
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