[FFmpeg-cvslog] avformat/mvdec: Sanity check SAMPLE_WIDTH

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Feb  2 20:47:10 2021 +0100| [ab82c105787fa81d1e35b9209f3d53e98be936a4] | committer: Michael Niedermayer

avformat/mvdec: Sanity check SAMPLE_WIDTH

Fixes: signed integer overflow: 999999999 * 8 cannot be represented in type 'int'
Fixes: 30048/clusterfuzz-testcase-minimized-ffmpeg_dem_MV_fuzzer-5864289917337600

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Peter Ross <pross at xvid.org>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=ab82c105787fa81d1e35b9209f3d53e98be936a4
---

 libavformat/mvdec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavformat/mvdec.c b/libavformat/mvdec.c
index d8f121bea5..c4fa980bf2 100644
--- a/libavformat/mvdec.c
+++ b/libavformat/mvdec.c
@@ -159,7 +159,10 @@ static int parse_audio_var(AVFormatContext *avctx, AVStream *st,
         st->codecpar->sample_rate = var_read_int(pb, size);
         avpriv_set_pts_info(st, 33, 1, st->codecpar->sample_rate);
     } else if (!strcmp(name, "SAMPLE_WIDTH")) {
-        st->codecpar->bits_per_coded_sample = var_read_int(pb, size) * 8;
+        uint64_t bpc = var_read_int(pb, size) * (uint64_t)8;
+        if (bpc > 16)
+            return AVERROR_INVALIDDATA;
+        st->codecpar->bits_per_coded_sample = bpc;
     } else
         return AVERROR_INVALIDDATA;