[FFmpeg-cvslog] avcodec/wmalosslessdec: Fix integer overflow with sliding in padding bits

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Jan 18 19:55:23 2020 +0100| [b8a0be93528187721a2414f66abbc252a258afa3] | committer: Michael Niedermayer

avcodec/wmalosslessdec: Fix integer overflow with sliding in padding bits

Fixes: signed integer overflow: -53716100 * 256 cannot be represented in type 'int'
Fixes: 20143/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WMALOSSLESS_fuzzer-5716604000403456

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=b8a0be93528187721a2414f66abbc252a258afa3
---

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

diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
index d841ec256a..8885487980 100644
--- a/libavcodec/wmalosslessdec.c
+++ b/libavcodec/wmalosslessdec.c
@@ -992,7 +992,7 @@ static int decode_subframe(WmallDecodeCtx *s)
             if (s->bits_per_sample == 16) {
                 *s->samples_16[c]++ = (int16_t) s->channel_residues[c][j] * (1 << padding_zeroes);
             } else {
-                *s->samples_32[c]++ = s->channel_residues[c][j] * (256 << padding_zeroes);
+                *s->samples_32[c]++ = s->channel_residues[c][j] * (256U << padding_zeroes);
             }
         }
     }