[vlc-devel] [PATCH] demux: mp4: fix crashes with VPx

[Tristan Matthews]

On Thu, Sep 22, 2016 at 7:36 AM, Tristan Matthews <tmatth at videolan.org> wrote:
> Reported by Vittorio Giovara.
> ---
>  modules/demux/mp4/essetup.c | 7 ++++++-
>  modules/demux/mp4/libmp4.c  | 4 ++++
>  2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/modules/demux/mp4/essetup.c b/modules/demux/mp4/essetup.c
> index 446bf84..2b4e611 100644
> --- a/modules/demux/mp4/essetup.c
> +++ b/modules/demux/mp4/essetup.c
> @@ -601,7 +601,12 @@ int SetupVideoES( demux_t *p_demux, mp4_track_t *p_track, MP4_Box_t *p_sample )
>                  p_track->fmt.video.i_bits_per_pixel = p_data->i_bit_depth;
>
>                  p_track->fmt.i_extra = p_data->i_codec_init_datasize;
> -                memcpy( p_track->fmt.p_extra, p_data->p_codec_init_data, p_data->i_codec_init_datasize );
> +                p_track->fmt.p_extra = malloc( p_track->fmt.i_extra );
> +                if( p_track->fmt.p_extra )
> +                {
> +                    memcpy( p_track->fmt.p_extra, p_data->p_codec_init_data,
> +                            p_data->i_codec_init_datasize );
> +                }
>              }
>          }
>
> diff --git a/modules/demux/mp4/libmp4.c b/modules/demux/mp4/libmp4.c
> index 6a36b7f..07e2094 100644
> --- a/modules/demux/mp4/libmp4.c
> +++ b/modules/demux/mp4/libmp4.c
> @@ -1650,6 +1650,10 @@ static int MP4_ReadBox_vpcC( stream_t *p_stream, MP4_Box_t *p_box )
>      MP4_GET2BYTES( p_vpcC->i_codec_init_datasize );
>      if( p_vpcC->i_codec_init_datasize > i_read )
>          p_vpcC->i_codec_init_datasize = i_read;
> +    p_vpcC->p_codec_init_data = malloc( i_read );
> +    if( !p_vpcC->p_codec_init_data )
> +        MP4_READBOX_EXIT( 0 );
> +
>      memcpy( p_vpcC->p_codec_init_data, p_peek, i_read );
>
>      MP4_READBOX_EXIT( 1 );
> --
> 2.9.3
>

Note that this only fixes the two crashes, playback of vp9 in mp4
files with this demuxer still doesn't work, playing e.g. this sample
http://people.videolan.org/~tmatth/akiyo.mp4 will just play black and
give the following warning (repeated):
core decoder warning: non-dated video buffer received

Best,
Tristan