avcodec/apedec: Fixes integer overflow of res+*data in do_apply_filter()

Fixes: signed integer overflow: 7400 + 2147482786 cannot be represented in type 'int'
Fixes: 18405/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_APE_fuzzer-5708834760294400
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index cfcf9a06c12a97cad0932b2059a420db8d0faa35..2b5bd759f561c28f8ba0a33c6844e02c71db66af 100644 (file)
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -1272,7 +1272,7 @@ static void do_apply_filter(APEContext *ctx, int version, APEFilter *f,
                                                      f->adaptcoeffs - order,
                                                      order, APESIGN(*data));
         res = (int)(res + (1U << (fracbits - 1))) >> fracbits;
-        res += *data;
+        res += (unsigned)*data;
         *data++ = res;
 
         /* Update the output history */