ffmpeg | branch: master | Michael Niedermayer <michael@niedermayer.cc> | Tue Jan 12 21:45:38 2021 +0100| [06e5c791949b63555aa4305df6ce9d2ffa45ec90] | committer: Michael Niedermayer avformat/asfdec_o: Check lang_idx Fixes: index 26981 out of bounds for type 'ASFStreamData [128]' Fixes: 27334/clusterfuzz-testcase-minimized-ffmpeg_dem_ASF_O_fuzzer-6197611002068992 Alternatively the array could be increased in size or the cases not fitting be ignored Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=06e5c791949b63555a...

libavformat/asfdec_o.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/libavformat/asfdec_o.c b/libavformat/asfdec_o.c index 3729adee2f..c1d90360b4 100644 --- a/libavformat/asfdec_o.c +++ b/libavformat/asfdec_o.c @@ -854,6 +854,8 @@ static int asf_read_ext_stream_properties(AVFormatContext *s, const GUIDParseTab st_num = avio_rl16(pb); st_num &= ASF_STREAM_NUM; lang_idx = avio_rl16(pb); // Stream Language ID Index + if (lang_idx >= ASF_MAX_STREAMS) + return AVERROR_INVALIDDATA; for (i = 0; i < asf->nb_streams; i++) { if (st_num == asf->asf_st[i]->stream_index) { st = s->streams[asf->asf_st[i]->index];