[FFmpeg-cvslog] avcodec/utvideodec: Fix integer overflow in decode_plane()

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Sun May 10 21:16:59 2020 +0200| [2a9ed44fe2bb2d85cb70adaacfc816b991451758] | committer: Michael Niedermayer

avcodec/utvideodec: Fix integer overflow in decode_plane()

Fixes: signed integer overflow: 2147483594 + 142 cannot be represented in type 'int'
Fixes: 20492/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_UTVIDEO_fuzzer-5658568101724160

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 876cfa67f37e944b0f42cb67b2de4e2e06f52e82)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2a9ed44fe2bb2d85cb70adaacfc816b991451758
---

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

diff --git a/libavcodec/utvideodec.c b/libavcodec/utvideodec.c
index 160528e007..56aecd514e 100644
--- a/libavcodec/utvideodec.c
+++ b/libavcodec/utvideodec.c
@@ -109,7 +109,7 @@ static int decode_plane(UtvideoContext *c, int plane_no,
                 for (i = 0; i < width * step; i += step) {
                     pix = fsym;
                     if (use_pred) {
-                        prev += pix;
+                        prev += (unsigned)pix;
                         pix   = prev;
                     }
                     dest[i] = pix;