[FFmpeg-devel] [PATCH 2/2] avcodec/dirac_dwt: Fix overflows in COMPOSE_HAARiH0/COMPOSE_HAARiL0

Michael Niedermayer michael at niedermayer.cc
Mon Jan 8 00:13:37 EET 2018


Fixes: 4830/clusterfuzz-testcase-minimized-5255392054476800
Fixes: signed integer overflow: 2147483646 - -7 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 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/dirac_dwt.h b/libavcodec/dirac_dwt.h
index f9828d95a4..1af41e0702 100644
--- a/libavcodec/dirac_dwt.h
+++ b/libavcodec/dirac_dwt.h
@@ -105,10 +105,10 @@ void ff_spatial_idwt_slice2(DWTContext *d, int y);
     (int)(((unsigned)(b2) - ((int)(-b0 + 9U*b1 + 9U*b3 - b4 + 16) >> 5)))
 
 #define COMPOSE_HAARiL0(b0, b1)\
-    (b0 - ((b1 + 1) >> 1))
+    ((int)(b0 - (unsigned)((int)(b1 + 1U) >> 1)))
 
 #define COMPOSE_HAARiH0(b0, b1)\
-    (b0 + b1)
+    ((int)(b0 + (unsigned)(b1)))
 
 #define COMPOSE_FIDELITYiL0(b0, b1, b2, b3, b4, b5, b6, b7, b8)\
     ((unsigned)b4 - ((int)(-8*(b0+(unsigned)b8) + 21*(b1+(unsigned)b7) - 46*(b2+(unsigned)b6) + 161*(b3+(unsigned)b5) + 128) >> 8))
-- 
2.15.1



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