diff options
| author | Michael Niedermayer <michael@niedermayer.cc> | 2018-11-27 23:37:03 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-12-02 15:45:24 +0100 |
| commit | d6b647e22138321decb7b08338dd3ae17f7a1cc3 (patch) | |
| tree | dd81db328423b35ab5abb0bec7451bd3e76ce9f3 | |
| parent | b84cda4b6399955b19040fc367f56da03e7cebe0 (diff) | |
| download | ffmpeg-d6b647e22138321decb7b08338dd3ae17f7a1cc3.tar.gz | |
avcodec/wmv2dec: Skip I frame if its smaller than 1/8 of the minimal size
Frames that small are not valid and of limited use for error concealment, while
being very computationally intensive to process.
Fixes: Timeout
Fixes: 11168/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMV2_fuzzer-5733782032744448
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit d6f4341522c3eafb046c47b115d79ce684a899fc)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/wmv2dec.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/libavcodec/wmv2dec.c b/libavcodec/wmv2dec.c index 98df381509..22fcd0388f 100644 --- a/libavcodec/wmv2dec.c +++ b/libavcodec/wmv2dec.c @@ -166,6 +166,14 @@ int ff_wmv2_decode_secondary_picture_header(MpegEncContext *s) } s->dc_table_index = get_bits1(&s->gb); + + // at minimum one bit per macroblock is required at least in a valid frame, + // we discard frames much smaller than this. Frames smaller than 1/8 of the + // smallest "black/skip" frame generally contain not much recoverable content + // while at the same time they have the highest computational requirements + // per byte + if (get_bits_left(&s->gb) * 8LL < (s->width+15)/16 * ((s->height+15)/16)) + return AVERROR_INVALIDDATA; } s->inter_intra_pred = 0; s->no_rounding = 1; |