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@gmail.com>

diff --git a/libavcodec/cbs_av1.c b/libavcodec/cbs_av1.c
index 29b316e01190c443c28a9a95a06160adaa80325f..0abcba9c60cf1efe171aa1fcd2e4b91b5d75f2cc 100644 (file)
--- 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);
     }