[FFmpeg-cvslog] avcodec/truemotion2: Fix multiple integer overflows in tm2_null_res_block()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Aug 15 23:22:50 2019 +0200| [cc78783ce5e8837d4f4ca43eedf2d299651e65ff] | committer: Michael Niedermayer

avcodec/truemotion2: Fix multiple integer overflows in tm2_null_res_block()

Fixes: signed integer overflow: 1795032576 + 598344192 cannot be represented in type 'int'
Fixes: 16196/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TRUEMOTION2_fuzzer-5636723419119616

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=cc78783ce5e8837d4f4ca43eedf2d299651e65ff
---

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

diff --git a/libavcodec/truemotion2.c b/libavcodec/truemotion2.c
index 5d6dfc24c3..27c876fd7d 100644
--- a/libavcodec/truemotion2.c
+++ b/libavcodec/truemotion2.c
@@ -619,7 +619,7 @@ static inline void tm2_null_res_block(TM2Context *ctx, AVFrame *pic, int bx, int
     ct = ctx->D[0] + ctx->D[1] + ctx->D[2] + ctx->D[3];
 
     if (bx > 0)
-        left = last[-1] - ct;
+        left = last[-1] - (unsigned)ct;
     else
         left = 0;
 
@@ -630,7 +630,7 @@ static inline void tm2_null_res_block(TM2Context *ctx, AVFrame *pic, int bx, int
     last[2] = right - (diff >> 2);
     last[3] = right;
     {
-        int tp = left;
+        unsigned tp = left;
 
         ctx->D[0] = (tp + (ct >> 2)) - left;
         left     += ctx->D[0];