[FFmpeg-cvslog] avcodec/alacdsp: Make intermediates unsigned

[Michael Niedermayer]

ffmpeg | branch: release/3.4 | Michael Niedermayer <michael at niedermayer.cc> | Thu Apr 28 23:34:53 2022 +0200| [cddda6d7e44b8a8a6805d60e43e0b652c8d72903] | committer: Michael Niedermayer

avcodec/alacdsp: Make intermediates unsigned

Fixes: signed integer overflow: -14914387 + -2147418648 cannot be represented in type 'int'
Fixes: 46464/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-474307197311385

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 8709f4c10a216cb3e11564bc392841e832f8e3b1)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cddda6d7e44b8a8a6805d60e43e0b652c8d72903
---

 libavcodec/alacdsp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/alacdsp.c b/libavcodec/alacdsp.c
index 8718d1b6b1..b3c1c424f3 100644
--- a/libavcodec/alacdsp.c
+++ b/libavcodec/alacdsp.c
@@ -29,12 +29,12 @@ static void decorrelate_stereo(int32_t *buffer[2], int nb_samples,
     int i;
 
     for (i = 0; i < nb_samples; i++) {
-        int32_t a, b;
+        uint32_t a, b;
 
         a = buffer[0][i];
         b = buffer[1][i];
 
-        a -= (int)(b * (unsigned)decorr_left_weight) >> decorr_shift;
+        a -= (int)(b * decorr_left_weight) >> decorr_shift;
         b += a;
 
         buffer[0][i] = b;