[FFmpeg-cvslog] avcodec/cfhd: Fix negative shift in cfhd_decode()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Feb 17 00:02:04 2021 +0100| [cd3ab3a09b7ea19ffef559efd4aae6292e196b42] | committer: Michael Niedermayer

avcodec/cfhd: Fix negative shift in cfhd_decode()

Fixes: left shift of negative value -1
Fixes: 30714/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_CFHD_fuzzer-4867823371419648

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=cd3ab3a09b7ea19ffef559efd4aae6292e196b42
---

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

diff --git a/libavcodec/cfhd.c b/libavcodec/cfhd.c
index dfd56ae6ed..1f2ee853c1 100644
--- a/libavcodec/cfhd.c
+++ b/libavcodec/cfhd.c
@@ -811,7 +811,7 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
                             const uint16_t q = s->quantisation;
 
                             for (i = 0; i < run; i++) {
-                                *coeff_data |= coeff << 8;
+                                *coeff_data |= coeff * 256;
                                 *coeff_data++ *= q;
                             }
                         } else {
@@ -842,7 +842,7 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
                             const uint16_t q = s->quantisation;
 
                             for (i = 0; i < run; i++) {
-                                *coeff_data |= coeff << 8;
+                                *coeff_data |= coeff * 256;
                                 *coeff_data++ *= q;
                             }
                         } else {