[FFmpeg-devel] [PATCH 3/5] avcodec/smacker: Fix integer overflows in pred[] in smka_decode_frame()

[Michael Niedermayer]

Fixes: signed integer overflow: -2147481503 + -32732 cannot be represented in type 'int'
Fixes: 17782/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SMACKAUD_fuzzer-5769672225456128

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/smacker.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libavcodec/smacker.c b/libavcodec/smacker.c
index a2950c455b..3dd0e929d8 100644
--- a/libavcodec/smacker.c
+++ b/libavcodec/smacker.c
@@ -742,7 +742,7 @@ static int smka_decode_frame(AVCodecContext *avctx, void *data,
                     return AVERROR_INVALIDDATA;
                 }
                 val |= h[3].values[res] << 8;
-                pred[1] += sign_extend(val, 16);
+                pred[1] += (unsigned)sign_extend(val, 16);
                 *samples++ = pred[1];
             } else {
                 if(vlc[0].table)
@@ -763,7 +763,7 @@ static int smka_decode_frame(AVCodecContext *avctx, void *data,
                     return AVERROR_INVALIDDATA;
                 }
                 val |= h[1].values[res] << 8;
-                pred[0] += sign_extend(val, 16);
+                pred[0] += (unsigned)sign_extend(val, 16);
                 *samples++ = pred[0];
             }
         }
-- 
2.23.0