[FFmpeg-cvslog] avcodec/truemotion2: Fix 2 integer overflows in tm2_update_block()

[Michael Niedermayer]

ffmpeg | branch: release/4.1 | Michael Niedermayer <michael at niedermayer.cc> | Sat Apr 20 01:05:44 2019 +0200| [5ea8ce3b37747b0e255d40b486c20943262c2334] | committer: Michael Niedermayer

avcodec/truemotion2: Fix 2 integer overflows in tm2_update_block()

Fixes: signed integer overflow: -2147483648 + -1 cannot be represented in type 'int'
Fixes: 14107/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TRUEMOTION2_fuzzer-5694078680825856

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 f4a1b8d409639b2394589efe20ad55410cce391c)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5ea8ce3b37747b0e255d40b486c20943262c2334
---

 libavcodec/truemotion2.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/truemotion2.c b/libavcodec/truemotion2.c
index 4bfe6e14ad..60354fd4a0 100644
--- a/libavcodec/truemotion2.c
+++ b/libavcodec/truemotion2.c
@@ -678,8 +678,8 @@ static inline void tm2_update_block(TM2Context *ctx, AVFrame *pic, int bx, int b
     /* update chroma */
     for (j = 0; j < 2; j++) {
         for (i = 0; i < 2; i++) {
-            U[i] = Uo[i] + GET_TOK(ctx, TM2_UPD);
-            V[i] = Vo[i] + GET_TOK(ctx, TM2_UPD);
+            U[i] = Uo[i] + (unsigned)GET_TOK(ctx, TM2_UPD);
+            V[i] = Vo[i] + (unsigned)GET_TOK(ctx, TM2_UPD);
         }
         U  += Ustride;
         V  += Vstride;