[FFmpeg-cvslog] avcodec/qdmc: Check input space in qdmc_get_vlc()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Oct 10 18:26:44 2019 +0200| [2c7975fe6f5c734fce9c59e8418c7f2de15a558d] | committer: Michael Niedermayer

avcodec/qdmc: Check input space in qdmc_get_vlc()

Fixes: Timeout (125sec -> 0.4sec)
Fixes: 18059/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_QDMC_fuzzer-5656195825664000

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2c7975fe6f5c734fce9c59e8418c7f2de15a558d
---

 libavcodec/qdmc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/qdmc.c b/libavcodec/qdmc.c
index 8bea1552e1..10ceb7aa55 100644
--- a/libavcodec/qdmc.c
+++ b/libavcodec/qdmc.c
@@ -367,6 +367,8 @@ static int qdmc_get_vlc(GetBitContext *gb, VLC *table, int flag)
 {
     int v;
 
+    if (get_bits_left(gb) < 1)
+        return AVERROR_INVALIDDATA;
     v = get_vlc2(gb, table->table, table->bits, 1);
     if (v < 0)
         return AVERROR_INVALIDDATA;