[FFmpeg-cvslog] avcodec/diracdec: Fix integer overflow in signed multiplication in UNPACK_ARITH()

[Michael Niedermayer]

ffmpeg | branch: release/3.1 | Michael Niedermayer <michael at niedermayer.cc> | Wed Jul 26 20:26:43 2017 +0200| [f4c8449238319d23e2e1bcd151c9af38e36c7eb3] | committer: Michael Niedermayer

avcodec/diracdec: Fix integer overflow in signed multiplication in UNPACK_ARITH()

Fixes: runtime error: signed integer overflow: 1073741823 * 4 cannot be represented in type 'int'
Fixes: 2729/clusterfuzz-testcase-minimized-5902915464069120

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 8e275a74b09cc87f4334ed572f919b7647d4bea1)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f4c8449238319d23e2e1bcd151c9af38e36c7eb3
---

 libavcodec/diracdec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index 9b3adfa9a8..160085f852 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -462,7 +462,8 @@ static inline int coeff_unpack_golomb(GetBitContext *gb, int qfactor, int qoffse
     static inline void coeff_unpack_arith_##n(DiracArith *c, int qfactor, int qoffset, \
                                               SubBand *b, type *buf, int x, int y) \
     { \
-        int coeff, sign, sign_pred = 0, pred_ctx = CTX_ZPZN_F1; \
+        int sign, sign_pred = 0, pred_ctx = CTX_ZPZN_F1; \
+        unsigned coeff; \
         const int mstride = -(b->stride >> (1+b->pshift)); \
         if (b->parent) { \
             const type *pbuf = (type *)b->parent->ibuf; \