[FFmpeg-cvslog] avcodec/interplayvideo: check decoding_map_size with video_data_size

[Michael Niedermayer]

ffmpeg | branch: release/4.1 | Michael Niedermayer <michael at niedermayer.cc> | Sun May 26 23:18:34 2019 +0200| [c4a14a630328b45d8b98309056d88563c7fef0c5] | committer: Michael Niedermayer

avcodec/interplayvideo: check decoding_map_size with video_data_size

Fixes: Timeout (90543 ms -> 59 ms)
Fixes: 14721/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_INTERPLAY_VIDEO_fuzzer-5697492148027392

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 914d6a7c1a7a1850b4053847a784b174c9146c55)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c4a14a630328b45d8b98309056d88563c7fef0c5
---

 libavcodec/interplayvideo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/interplayvideo.c b/libavcodec/interplayvideo.c
index deaa09cba6..4313fdf7ac 100644
--- a/libavcodec/interplayvideo.c
+++ b/libavcodec/interplayvideo.c
@@ -1260,7 +1260,7 @@ static int ipvideo_decode_frame(AVCodecContext *avctx,
             s->decoding_map_size = ((s->avctx->width / 8) * (s->avctx->height / 8)) * 2;
             s->decoding_map = buf + 8 + 14; /* 14 bits of op data */
             video_data_size -= s->decoding_map_size + 14;
-            if (video_data_size <= 0)
+            if (video_data_size <= 0 || s->decoding_map_size == 0)
                 return AVERROR_INVALIDDATA;
 
             if (buf_size < 8 + s->decoding_map_size + 14 + video_data_size)