[FFmpeg-devel] [PATCH 1/3] avcodec/diracdec: Fix overflow in DC computation

Michael Niedermayer michael at niedermayer.cc
Sun Sep 10 02:32:50 EEST 2017


Fixes: runtime error: signed integer overflow: 11896 + 2147483646 cannot be represented in type 'int'
Fixes: 3053/clusterfuzz-testcase-minimized-6355082062856192

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/diracdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/diracdec.c b/libavcodec/diracdec.c
index f2aed6057d..0abb8b0599 100644
--- a/libavcodec/diracdec.c
+++ b/libavcodec/diracdec.c
@@ -1421,7 +1421,7 @@ static void decode_block_params(DiracContext *s, DiracArith arith[8], DiracBlock
     if (!block->ref) {
         pred_block_dc(block, stride, x, y);
         for (i = 0; i < 3; i++)
-            block->u.dc[i] += dirac_get_arith_int(arith+1+i, CTX_DC_F1, CTX_DC_DATA);
+            block->u.dc[i] += (unsigned)dirac_get_arith_int(arith+1+i, CTX_DC_F1, CTX_DC_DATA);
         return;
     }
 
-- 
2.14.1



More information about the ffmpeg-devel mailing list