[FFmpeg-cvslog] avcodec/ralf: fix undefined shift

[Michael Niedermayer]

ffmpeg | branch: release/4.2 | Michael Niedermayer <michael at niedermayer.cc> | Sat Aug 17 19:18:31 2019 +0200| [a7f6b27e3c3a2106ac21cde3013471e9aec08ad5] | committer: Michael Niedermayer

avcodec/ralf: fix undefined shift

Fixes: left shift of negative value -2
Fixes: 16145/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RALF_fuzzer-5146671058518016

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 0ee886988e75b3c22cabc2ca0fadcf8e4f787640)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a7f6b27e3c3a2106ac21cde3013471e9aec08ad5
---

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

diff --git a/libavcodec/ralf.c b/libavcodec/ralf.c
index 619fd7126a..d2d803b0d4 100644
--- a/libavcodec/ralf.c
+++ b/libavcodec/ralf.c
@@ -300,8 +300,8 @@ static int decode_channel(RALFContext *ctx, GetBitContext *gb, int ch,
         t = get_vlc2(gb, code_vlc->table, code_vlc->bits, 2);
         code1 = t / range2;
         code2 = t % range2;
-        dst[i]     = extend_code(gb, code1, range, 0) << add_bits;
-        dst[i + 1] = extend_code(gb, code2, range, 0) << add_bits;
+        dst[i]     = extend_code(gb, code1, range, 0) * (1 << add_bits);
+        dst[i + 1] = extend_code(gb, code2, range, 0) * (1 << add_bits);
         if (add_bits) {
             dst[i]     |= get_bits(gb, add_bits);
             dst[i + 1] |= get_bits(gb, add_bits);