[FFmpeg-devel] [PATCH 1/2] avformat/mpegts: use actually read packet size in mpegts_resync special case

[Marton Balint]

On Fri, 17 Sep 2021, Michael Niedermayer wrote:

> Fixes: infinite loop
> Fixes: 37986/clusterfuzz-testcase-minimized-ffmpeg_dem_MPEGTSRAW_fuzzer-5292311517462528 -

LGTM, thanks.

Marton

>
> 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/mpegts.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
> index fe89d4fb9f3..bd13118f7f7 100644
> --- a/libavformat/mpegts.c
> +++ b/libavformat/mpegts.c
> @@ -2865,8 +2865,8 @@ static int mpegts_resync(AVFormatContext *s, int seekback, const uint8_t *curren
>     int64_t back = FFMIN(seekback, pos);
>
>     //Special case for files like 01c56b0dc1.ts
> -    if (current_packet[0] == 0x80 && current_packet[12] == 0x47) {
> -        avio_seek(pb, 12 - back, SEEK_CUR);
> +    if (current_packet[0] == 0x80 && current_packet[12] == 0x47 && pos >= TS_PACKET_SIZE) {
> +        avio_seek(pb, 12 - TS_PACKET_SIZE, SEEK_CUR);
>         return 0;
>     }
>
> -- 
> 2.17.1
>
> _______________________________________________
> 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".
>