[FFmpeg-cvslog] avcodec/adpcm: Fix left shifts in AV_CODEC_ID_ADPCM_EA

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Sep 27 12:04:57 2019 +0200| [8695fbec573b0d434cf2e703a0d45742a09a5d94] | committer: Michael Niedermayer

avcodec/adpcm: Fix left shifts in AV_CODEC_ID_ADPCM_EA

Fixes: left shift of negative value -1
Fixes: 17683/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ADPCM_EA_R2_fuzzer-5111690013704192

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=8695fbec573b0d434cf2e703a0d45742a09a5d94
---

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

diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 7f2ebfc99d..8ed2b6c9d9 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -1380,10 +1380,10 @@ static int adpcm_decode_frame(AVCodecContext *avctx, void *data,
 
                     for (count2=0; count2<28; count2++) {
                         if (count2 & 1)
-                            next_sample = sign_extend(byte,    4) << shift;
+                            next_sample = (unsigned)sign_extend(byte,    4) << shift;
                         else {
                             byte = bytestream2_get_byte(&gb);
-                            next_sample = sign_extend(byte >> 4, 4) << shift;
+                            next_sample = (unsigned)sign_extend(byte >> 4, 4) << shift;
                         }
 
                         next_sample += (current_sample  * coeff1) +