[FFmpeg-devel] [PATCH 03/11] avformat/mxfdec: Check type before setting sub_descriptors_refs

[Tomas Härdin]

tis 2020-10-20 klockan 22:56 +0200 skrev Michael Niedermayer:
> Fixes: memleak
> Fixes: 26352/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5201158714687488
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavformat/mxfdec.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
> index d16a7af0df..0313cf4a28 100644
> --- a/libavformat/mxfdec.c
> +++ b/libavformat/mxfdec.c
> @@ -1172,6 +1172,8 @@ static int mxf_read_generic_descriptor(void *arg, AVIOContext *pb, int tag, int
>  
>      switch(tag) {
>      case 0x3F01:
> +        if (descriptor->type != MultipleDescriptor)
> +            return AVERROR_INVALIDDATA;
>          return mxf_read_strong_ref_array(pb, &descriptor->sub_descriptors_refs,
>                                               &descriptor->sub_descriptors_count);
>      case 0x3002: /* ContainerDuration */

mxf_read_strong_ref_array() is called in more places than this. A
better solution would be to make freeing sub_descriptors_refs in
mxf_free_metadataset() not depends on type

/Tomas