[FFmpeg-cvslog] avcodec/adpcm: Fix undefined behavior with negative predictions in IMA OKI

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Oct 25 11:12:02 2019 +0200| [7786f6c30e77a393b72ded01baa4250738925509] | committer: Michael Niedermayer

avcodec/adpcm: Fix undefined behavior with negative predictions in IMA OKI

Fixes: left shift of negative value -30
Fixes: 18392/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ADPCM_IMA_OKI_fuzzer-5631771831435264

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=7786f6c30e77a393b72ded01baa4250738925509
---

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

diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 53d8d0be6a..edf7052636 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -342,7 +342,7 @@ static inline int16_t adpcm_ima_oki_expand_nibble(ADPCMChannelStatus *c, int nib
     c->predictor = av_clip_intp2(predictor, 11);
     c->step_index = step_index;
 
-    return c->predictor << 4;
+    return c->predictor * 16;
 }
 
 static inline int16_t adpcm_ct_expand_nibble(ADPCMChannelStatus *c, int8_t nibble)