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

[Michael Niedermayer]

ffmpeg | branch: release/4.1 | Michael Niedermayer <michael at niedermayer.cc> | Sun May  5 00:31:24 2019 +0200| [57e9b3cac1b646967ef4c228b1463338e403ee52] | committer: Michael Niedermayer

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

Fixes: signed integer overflow: -1877966852 + -469491713 cannot be represented in type 'int'
Fixes: 14561/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TRUEMOTION2_fuzzer-5167608359288832

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 8eecf761a65baf4ce6f25c0a149819cc9414c0f0)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=57e9b3cac1b646967ef4c228b1463338e403ee52
---

 libavcodec/truemotion2.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/libavcodec/truemotion2.c b/libavcodec/truemotion2.c
index 60354fd4a0..8936741c6c 100644
--- a/libavcodec/truemotion2.c
+++ b/libavcodec/truemotion2.c
@@ -692,15 +692,15 @@ static inline void tm2_update_block(TM2Context *ctx, AVFrame *pic, int bx, int b
     TM2_RECALC_BLOCK(V, Vstride, (clast + 2), (ctx->CD + 2));
 
     /* update deltas */
-    ctx->D[0] = Yo[3] - last[3];
-    ctx->D[1] = Yo[3 + oYstride] - Yo[3];
-    ctx->D[2] = Yo[3 + oYstride * 2] - Yo[3 + oYstride];
-    ctx->D[3] = Yo[3 + oYstride * 3] - Yo[3 + oYstride * 2];
+    ctx->D[0] = (unsigned)Yo[3] - last[3];
+    ctx->D[1] = (unsigned)Yo[3 + oYstride] - Yo[3];
+    ctx->D[2] = (unsigned)Yo[3 + oYstride * 2] - Yo[3 + oYstride];
+    ctx->D[3] = (unsigned)Yo[3 + oYstride * 3] - Yo[3 + oYstride * 2];
 
     for (j = 0; j < 4; j++) {
         d = last[3];
         for (i = 0; i < 4; i++) {
-            Y[i]    = Yo[i] + GET_TOK(ctx, TM2_UPD);
+            Y[i]    = Yo[i] + (unsigned)GET_TOK(ctx, TM2_UPD);
             last[i] = Y[i];
         }
         ctx->D[j] = last[3] - d;