[FFmpeg-cvslog] avcodec/leaddec: Check remaining bits in decode_block()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Dec 15 02:18:04 2023 +0100| [d909d8e5e0fbce42ecb10ee6e73def1f1e42ece4] | committer: Michael Niedermayer

avcodec/leaddec: Check remaining bits in decode_block()

Fixes: Timeout
Fixes: 64163/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_LEAD_fuzzer-6418925835124736

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=d909d8e5e0fbce42ecb10ee6e73def1f1e42ece4
---

 libavcodec/leaddec.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/leaddec.c b/libavcodec/leaddec.c
index ede52fba5a..4e97479b03 100644
--- a/libavcodec/leaddec.c
+++ b/libavcodec/leaddec.c
@@ -104,6 +104,9 @@ static int decode_block(LeadContext * s, GetBitContext * gb,
 
     s->bdsp.clear_block(block);
 
+    if (get_bits_left(gb) <= 0)
+        return AVERROR_INVALIDDATA;
+
     size = get_vlc2(gb, dc_table, dc_bits, 1);
     if (size < 0)
         return AVERROR_INVALIDDATA;