[FFmpeg-cvslog] avcodec/bonk: Fix undefined overflow in predictor_calc_error()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Oct  5 14:17:05 2023 +0200| [cd66606a8f9124a75a126d579c18f263b874d3a5] | committer: Michael Niedermayer

avcodec/bonk: Fix undefined overflow in predictor_calc_error()

Fixes: signed integer overflow: -2146469728 - 1488954 cannot be represented in type 'int'
Fixes: 62490/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BONK_fuzzer-5612782399389696

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=cd66606a8f9124a75a126d579c18f263b874d3a5
---

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

diff --git a/libavcodec/bonk.c b/libavcodec/bonk.c
index 6cd6a0af61..65679e5fb6 100644
--- a/libavcodec/bonk.c
+++ b/libavcodec/bonk.c
@@ -270,7 +270,7 @@ static inline int shift(int a, int b)
 
 static int predictor_calc_error(int *k, int *state, int order, int error)
 {
-    int i, x = error - shift_down(k[order-1] * (unsigned)state[order-1], LATTICE_SHIFT);
+    int i, x = error - (unsigned)shift_down(k[order-1] * (unsigned)state[order-1], LATTICE_SHIFT);
     int *k_ptr = &(k[order-2]),
         *state_ptr = &(state[order-2]);