[FFmpeg-cvslog] avcodec/sonic: Use unsigned for predictor_k to avoid undefined behavior

[Michael Niedermayer]

ffmpeg | branch: release/4.2 | Michael Niedermayer <michael at niedermayer.cc> | Tue Feb  8 00:43:56 2022 +0100| [93445cbbf40e84c16851005ff602c170d14f844d] | committer: Michael Niedermayer

avcodec/sonic: Use unsigned for predictor_k to avoid undefined behavior

Fixes: signed integer overflow: -1094995529 * 24 cannot be represented in type 'int'
Fixes: 44436/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SONIC_fuzzer-4874459459223552

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 28008bf95ed9b2ab5945ae6658358ad7c7f1df35)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=93445cbbf40e84c16851005ff602c170d14f844d
---

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

diff --git a/libavcodec/sonic.c b/libavcodec/sonic.c
index 0a3b84163e..b6bb1c3a84 100644
--- a/libavcodec/sonic.c
+++ b/libavcodec/sonic.c
@@ -1018,7 +1018,7 @@ static int sonic_decode_frame(AVCodecContext *avctx,
 
     // dequantize
     for (i = 0; i < s->num_taps; i++)
-        s->predictor_k[i] *= s->tap_quant[i];
+        s->predictor_k[i] *= (unsigned) s->tap_quant[i];
 
     if (s->lossless)
         quant = 1;