From cbcbefdc3b4cbc917d2f8b2dd216fb12121a838b Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Sat, 17 Feb 2018 23:54:44 +0100
Subject: [PATCH] avcodec/diracdec: Use int64 in global mv to prevent overflow

Fixes: runtime error: signed integer overflow: 361 * -6295541 cannot be represented in type 'int'
Fixes: 5911/clusterfuzz-testcase-minimized-6450382197751808

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/diracdec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index 530e1c6ffd..e3afbf14be 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -1399,8 +1399,8 @@ static void global_mv(DiracContext *s, DiracBlock *block, int x, int y, int ref)
     int *c      = s->globalmc[ref].perspective;
 
     int m       = (1<<ep) - (c[0]*x + c[1]*y);
-    int mx      = m * ((A[0][0] * x + A[0][1]*y) + (1<<ez) * b[0]);
-    int my      = m * ((A[1][0] * x + A[1][1]*y) + (1<<ez) * b[1]);
+    int64_t mx  = m * (int64_t)((A[0][0] * x + A[0][1]*y) + (1<<ez) * b[0]);
+    int64_t my  = m * (int64_t)((A[1][0] * x + A[1][1]*y) + (1<<ez) * b[1]);
 
     block->u.mv[ref][0] = (mx + (1<<(ez+ep))) >> (ez+ep);
     block->u.mv[ref][1] = (my + (1<<(ez+ep))) >> (ez+ep);