[FFmpeg-devel] [PATCH] avcodec/dirac_dwt: Fix integer overflow in COMPOSE_DD137iL0()

Michael Niedermayer michael at niedermayer.cc
Tue Nov 14 05:20:03 EET 2017


Fixes: 4035/clusterfuzz-testcase-minimized-6479308925173760
Fixes: runtime error: signed integer overflow: 9 * 402653183 cannot be represented in type 'int'

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/dirac_dwt.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/dirac_dwt.h b/libavcodec/dirac_dwt.h
index 35ed8857e9..f9a9e9e1b3 100644
--- a/libavcodec/dirac_dwt.h
+++ b/libavcodec/dirac_dwt.h
@@ -102,7 +102,7 @@ void ff_spatial_idwt_slice2(DWTContext *d, int y);
     (b2 + ((int)(-b0 + 9U*b1 + 9U*b3 - b4 + 8) >> 4))
 
 #define COMPOSE_DD137iL0(b0, b1, b2, b3, b4)\
-    (b2 - ((-b0 + 9*b1 + 9*b3 - b4 + 16) >> 5))
+    (b2 - ((int)(-b0 + 9U*b1 + 9U*b3 - b4 + 16) >> 5))
 
 #define COMPOSE_HAARiL0(b0, b1)\
     (b0 - ((b1 + 1) >> 1))
-- 
2.15.0



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