[FFmpeg-cvslog] avcodec/apedec: Fix undefined integer overflow in decode_array_0000()

[Michael Niedermayer]

ffmpeg | branch: release/2.8 | Michael Niedermayer <michael at niedermayer.cc> | Sat Dec  7 20:55:16 2019 +0100| [cee643d7fbcdb016525425eaa897426ebef01345] | committer: Michael Niedermayer

avcodec/apedec: Fix undefined integer overflow in decode_array_0000()

Fixes: signed integer overflow: -2143289344 - 6246400 cannot be represented in type 'int'
Fixes: 19239/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5173755680915456

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 a3655bb02c21e70573335e9396632f64b2589536)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=cee643d7fbcdb016525425eaa897426ebef01345
---

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

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index cd9b5476b9..0f4ec77fbd 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -610,7 +610,7 @@ static void decode_array_0000(APEContext *ctx, GetBitContext *gb,
     ksummin = rice->k ? (1 << rice->k + 6) : 0;
     for (; i < blockstodecode; i++) {
         out[i] = get_rice_ook(&ctx->gb, rice->k);
-        rice->ksum += out[i] - out[i - 64];
+        rice->ksum += out[i] - (unsigned)out[i - 64];
         while (rice->ksum < ksummin) {
             rice->k--;
             ksummin = rice->k ? ksummin >> 1 : 0;