[FFmpeg-cvslog] avcodec/mv30: check mode_size vs. input space

[Michael Niedermayer]

ffmpeg | branch: release/4.3 | Michael Niedermayer <michael at niedermayer.cc> | Sat Jun 13 16:03:14 2020 +0200| [95b9ac040ef7ada89f6885c8e6c1a77c9018954e] | committer: Michael Niedermayer

avcodec/mv30: check mode_size vs. input space

Fixes: Timeout (longer than my patience vs 1sec)
Fixes: 22984/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MV30_fuzzer-5630021988515840

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 75e2ac4f0752649a0b9486e6825ef68341ee974d)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=95b9ac040ef7ada89f6885c8e6c1a77c9018954e
---

 libavcodec/mv30.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/mv30.c b/libavcodec/mv30.c
index 013a5753fe..76b9170eaf 100644
--- a/libavcodec/mv30.c
+++ b/libavcodec/mv30.c
@@ -410,6 +410,9 @@ static int decode_intra(AVCodecContext *avctx, GetBitContext *gb, AVFrame *frame
     int ret;
 
     mgb = *gb;
+    if (get_bits_left(gb) < s->mode_size * 8)
+        return AVERROR_INVALIDDATA;
+
     skip_bits_long(gb, s->mode_size * 8);
 
     linesize[0] = frame->linesize[0];