[FFmpeg-devel] [PATCH v4] avcodec/decode: validate hw_frames_ctx when AVHWAccel.free_frame_priv is used

[Lynne]

Nov 21, 2023, 07:02 by dmitry.v.rogozhkin-at-intel.com at ffmpeg.org:

> On Tue, 2023-11-21 at 06:17 +0100, Lynne wrote:
>
>> Nov 21, 2023, 05:38 by dmitry.v.rogozhkin-at-intel.com at ffmpeg.org:
>>
>> > Validate that a hw_frames_ctx is available before using it for
>> > the AVHWAccel.free_frame_priv callback, and don't require it to
>> > be present when the callback is not in use by the HWAccel.
>> > 
>> > v2: check for free_frame_priv (Hendrik)
>> > v3: return EINVAL (Christoph Reiter)
>> > v4: better commit message (Hendrik)
>> > 
>> > See[1]: https://github.com/msys2/MINGW-packages/pull/19050
>> > Fixes: be07145109 ("avcodec: add AVHWAccel.free_frame_priv
>> > callback")
>> > CC: Lynne <dev at lynne.ee>
>> > CC: Christoph Reiter <reiter.christoph at gmail.com>
>> > Signed-off-by: Dmitry Rogozhkin <dmitry.v.rogozhkin at intel.com>
>> > ---
>> >  libavcodec/decode.c | 18 +++++++++++++-----
>> >  1 file changed, 13 insertions(+), 5 deletions(-)
>> > 
>> > diff --git a/libavcodec/decode.c b/libavcodec/decode.c
>> > index ad39021..50c3995 100644
>> > --- a/libavcodec/decode.c
>> > +++ b/libavcodec/decode.c
>> > @@ -1838,17 +1838,25 @@ int ff_copy_palette(void *dst, const
>> > AVPacket *src, void *logctx)
>> >  int ff_hwaccel_frame_priv_alloc(AVCodecContext *avctx, void
>> > **hwaccel_picture_private)
>> >  {
>> >  const FFHWAccel *hwaccel = ffhwaccel(avctx->hwaccel);
>> > -    AVHWFramesContext *frames_ctx;
>> > 
>> >  if (!hwaccel || !hwaccel->frame_priv_data_size)
>> >  return 0;
>> > 
>> >  av_assert0(!*hwaccel_picture_private);
>> > 
>> > -    frames_ctx = (AVHWFramesContext *)avctx->hw_frames_ctx->data;
>> > -    *hwaccel_picture_private = ff_refstruct_alloc_ext(hwaccel-
>> > >frame_priv_data_size, 0,
>> > -                                                      frames_ctx-
>> > >device_ctx,
>> > -                                                      hwaccel-
>> > >free_frame_priv);
>> > +    if (hwaccel->free_frame_priv) {
>> > +        AVHWFramesContext *frames_ctx;
>> > +
>> > +        if (!avctx->hw_frames_ctx)
>> > +            return AVERROR(EINVAL);
>> > +
>> > +        *hwaccel_picture_private = ff_refstruct_alloc_ext(hwaccel-
>> > >frame_priv_data_size, 0,
>> > +                                                          frames_c
>> > tx->device_ctx,
>> > +                                                          hwaccel-
>> > >free_frame_priv);
>> > +    } else {
>> > +        *hwaccel_picture_private = ff_refstruct_allocz(hwaccel-
>> > >frame_priv_data_size);
>> > +    }
>> > +
>> >  if (!*hwaccel_picture_private)
>> >  return AVERROR(ENOMEM);
>> > 
>>
>> You never set frames_ctx in this patch.
>>
>
> Thank you for the catch. Yep, I did a type doing v3. Fixed now. See v5.
>

Pushed, thanks