[FFmpeg-cvslog] avcodec/mobiclip: Avoid undefined integer overflow in MV computation

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Mar  2 00:19:21 2021 +0100| [4dc039b4c7c74567af4a31ab1d212139f5225b69] | committer: Michael Niedermayer

avcodec/mobiclip: Avoid undefined integer overflow in MV computation

Fixes: signed integer overflow: 1 + 2147483647 cannot be represented in type 'int'
Fixes: 30877/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MOBICLIP_fuzzer-4775601145774080

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4dc039b4c7c74567af4a31ab1d212139f5225b69
---

 libavcodec/mobiclip.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mobiclip.c b/libavcodec/mobiclip.c
index e5c6617325..9392ab947e 100644
--- a/libavcodec/mobiclip.c
+++ b/libavcodec/mobiclip.c
@@ -1091,8 +1091,8 @@ static int predict_motion(AVCodecContext *avctx,
             sidx += 6;
 
         if (index > 0) {
-            mv.x = mv.x + get_se_golomb(gb);
-            mv.y = mv.y + get_se_golomb(gb);
+            mv.x = mv.x + (unsigned)get_se_golomb(gb);
+            mv.y = mv.y + (unsigned)get_se_golomb(gb);
         }
         if (mv.x >= INT_MAX || mv.y >= INT_MAX)
             return AVERROR_INVALIDDATA;