[FFmpeg-cvslog] avcodec/dpcm: Fix integer overflow in AV_CODEC_ID_GREMLIN_DPCM

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Jan 22 23:11:47 2020 +0100| [b1aecad9eae900b9c3054392994d150d5ae572c5] | committer: Michael Niedermayer

avcodec/dpcm: Fix integer overflow in AV_CODEC_ID_GREMLIN_DPCM

Fixes: signed integer overflow: -2147479324 + -32568 cannot be represented in type 'int'
Fixes: 20103/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_GREMLIN_DPCM_fuzzer-5667667579240448

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=b1aecad9eae900b9c3054392994d150d5ae572c5
---

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

diff --git a/libavcodec/dpcm.c b/libavcodec/dpcm.c
index 7d3934ee35..5958081b66 100644
--- a/libavcodec/dpcm.c
+++ b/libavcodec/dpcm.c
@@ -367,7 +367,7 @@ static int dpcm_decode_frame(AVCodecContext *avctx, void *data,
         while (output_samples < samples_end) {
             uint8_t n = bytestream2_get_byteu(&gb);
 
-            *output_samples++ = s->sample[idx] += s->array[n];
+            *output_samples++ = s->sample[idx] += (unsigned)s->array[n];
             idx ^= 1;
         }
         }