[FFmpeg-cvslog] avcodec/pgxdec: Fix invalid shift in write_frame_*

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Jul 25 23:14:10 2020 +0200| [165d6b876b602ec0f6122867b281b8dd6a5f8a5f] | committer: Michael Niedermayer

avcodec/pgxdec: Fix invalid shift in write_frame_*

Fixes: left shift of negative value -121
Fixes: 23911/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_PGX_fuzzer-4986800258154496

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=165d6b876b602ec0f6122867b281b8dd6a5f8a5f
---

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

diff --git a/libavcodec/pgxdec.c b/libavcodec/pgxdec.c
index a72d6fe6fe..150f8bbf66 100644
--- a/libavcodec/pgxdec.c
+++ b/libavcodec/pgxdec.c
@@ -102,7 +102,7 @@ error:
         for (i = 0; i < height; i++) {                                                      \
             PIXEL *line = (PIXEL*)frame->data[0] + i*frame->linesize[0]/sizeof(PIXEL);      \
             for (j = 0; j < width; j++) {                                                   \
-                int val;                                                                    \
+                unsigned val;                                                               \
                 if (sign)                                                                   \
                     val = (PIXEL)bytestream2_get_ ##suffix(g) + (1 << (depth - 1));         \
                 else                                                                        \