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

Michael Niedermayer michael at niedermayer.cc
Mon Sep 18 03:54:58 EEST 2017


Fixes: runtime error: signed integer overflow: 161 * 13872281 cannot be represented in type 'int'

Fixes: 3295/clusterfuzz-testcase-minimized-4738998142500864

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 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/dirac_dwt.h b/libavcodec/dirac_dwt.h
index adf5178714..755d5e5d2d 100644
--- a/libavcodec/dirac_dwt.h
+++ b/libavcodec/dirac_dwt.h
@@ -111,10 +111,10 @@ void ff_spatial_idwt_slice2(DWTContext *d, int y);
     (b0 + b1)
 
 #define COMPOSE_FIDELITYiL0(b0, b1, b2, b3, b4, b5, b6, b7, b8)\
-    (b4 - ((-8*(b0+b8) + 21*(b1+b7) - 46*(b2+b6) + 161*(b3+b5) + 128) >> 8))
+    (b4 - ((int)(-8*(b0+(unsigned)b8) + 21*(b1+(unsigned)b7) - 46*(b2+(unsigned)b6) + 161*(b3+(unsigned)b5) + 128) >> 8))
 
 #define COMPOSE_FIDELITYiH0(b0, b1, b2, b3, b4, b5, b6, b7, b8)\
-    (b4 + ((-2*(b0+b8) + 10*(b1+b7) - 25*(b2+b6) + 81*(b3+b5) + 128) >> 8))
+    (b4 + ((int)(-2*(b0+(unsigned)b8) + 10*(b1+(unsigned)b7) - 25*(b2+(unsigned)b6) +  81*(b3+(unsigned)b5) + 128) >> 8))
 
 #define COMPOSE_DAUB97iL1(b0, b1, b2)\
     (b1 - ((int)(1817*(b0 + (unsigned)b2) + 2048) >> 12))
-- 
2.14.1



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