[FFmpeg-devel] [PATCH 1/2] avcodec/alacdsp: fix integer overflow in decorrelate_stereo()

[Michael Niedermayer]

Fixes: signed integer overflow: -16777216 * 131 cannot be represented in type 'int'
Fixes: 23835/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-5669943160078336

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

diff --git a/libavcodec/alacdsp.c b/libavcodec/alacdsp.c
index 9996eb4319..8718d1b6b1 100644
--- a/libavcodec/alacdsp.c
+++ b/libavcodec/alacdsp.c
@@ -34,7 +34,7 @@ static void decorrelate_stereo(int32_t *buffer[2], int nb_samples,
         a = buffer[0][i];
         b = buffer[1][i];
 
-        a -= (b * decorr_left_weight) >> decorr_shift;
+        a -= (int)(b * (unsigned)decorr_left_weight) >> decorr_shift;
         b += a;
 
         buffer[0][i] = b;
-- 
2.17.1