[FFmpeg-cvslog] avcodec/qoadec: Fix undefined overflow in lms_predict

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Mar 26 01:58:25 2024 +0100| [7eabe564365f4130c4d8f1d50fd835b45dc46355] | committer: Michael Niedermayer

avcodec/qoadec: Fix undefined overflow in lms_predict

Fixes: signed integer overflow: -1575944192 + -602931200 cannot be represented in type 'int'
Fixes: 62285/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_QOA_fuzzer-6470469339185152

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7eabe564365f4130c4d8f1d50fd835b45dc46355
---

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

diff --git a/libavcodec/qoadec.c b/libavcodec/qoadec.c
index 75099d1199..c5cf351f9c 100644
--- a/libavcodec/qoadec.c
+++ b/libavcodec/qoadec.c
@@ -67,7 +67,7 @@ static int qoa_lms_predict(QOAChannel *lms)
 {
     int prediction = 0;
     for (int i = 0; i < QOA_LMS_LEN; i++)
-        prediction += lms->weights[i] * lms->history[i];
+        prediction += (unsigned)lms->weights[i] * lms->history[i];
     return prediction >> 13;
 }