[FFmpeg-cvslog] avcodec/cbs_av1: Fix writing uvlc numbers >= INT_MAX

[Andreas Rheinhardt]

ffmpeg | branch: release/4.1 | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Thu Jun 18 14:37:38 2020 +0200| [8d90a8cb37c1ec2596d6b2e0cdfeb0975b87bfee] | committer: Andreas Rheinhardt

avcodec/cbs_av1: Fix writing uvlc numbers >= INT_MAX

Fixes: assertion failure
Fixes: left shift of 1 by 31 places cannot be represented in type 'int'
Fixes: 23264/clusterfuzz-testcase-minimized-ffmpeg_BSF_AV1_METADATA_fuzzer-6308429248593920

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
(cherry picked from commit 6f06c17a55137855c67ba4a7b6778ca34ddbbe6b)
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=8d90a8cb37c1ec2596d6b2e0cdfeb0975b87bfee
---

 libavcodec/cbs_av1.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/libavcodec/cbs_av1.c b/libavcodec/cbs_av1.c
index 8e962b8721..ff1323de3d 100644
--- a/libavcodec/cbs_av1.c
+++ b/libavcodec/cbs_av1.c
@@ -125,8 +125,9 @@ static int cbs_av1_write_uvlc(CodedBitstreamContext *ctx, PutBitContext *pbc,
         put_bits(pbc, 1, 1);
     } else {
         zeroes = av_log2(value + 1);
-        v = value - (1 << zeroes) + 1;
-        put_bits(pbc, zeroes + 1, 1);
+        v = value - (1U << zeroes) + 1;
+        put_bits(pbc, zeroes, 0);
+        put_bits(pbc, 1, 1);
         put_bits(pbc, zeroes, v);
     }