[FFmpeg-cvslog] avcodec/apedec: make left/right unsigned to avoid undefined behavior

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Tue Jul  2 12:13:19 2019 +0200| [bf778af1493b0814696307432763246fb53c75e7] | committer: Michael Niedermayer

avcodec/apedec: make left/right unsigned to avoid undefined behavior

Fixes: signed integer overflow: 755176387 + 1515360583 cannot be represented in type 'int'
Fixes: 15506/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5706859232624640

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=bf778af1493b0814696307432763246fb53c75e7
---

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

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index 27425b17e6..7a7097e7a4 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -1376,7 +1376,7 @@ static void ape_unpack_mono(APEContext *ctx, int count)
 
 static void ape_unpack_stereo(APEContext *ctx, int count)
 {
-    int32_t left, right;
+    unsigned left, right;
     int32_t *decoded0 = ctx->decoded[0];
     int32_t *decoded1 = ctx->decoded[1];
 
@@ -1393,7 +1393,7 @@ static void ape_unpack_stereo(APEContext *ctx, int count)
 
     /* Decorrelate and scale to output depth */
     while (count--) {
-        left = *decoded1 - (*decoded0 / 2);
+        left = *decoded1 - (unsigned)(*decoded0 / 2);
         right = left + *decoded0;
 
         *(decoded0++) = left;