[FFmpeg-devel] [PATCH] avcodec/agm: Check that there is available input in read_code() before reading it

[Michael Niedermayer]

Fixes: out of array access
Fixes: 13997/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AGM_fuzzer-5701427252428800

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/agm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/agm.c b/libavcodec/agm.c
index b0e8b80f81..8e4d6eb342 100644
--- a/libavcodec/agm.c
+++ b/libavcodec/agm.c
@@ -88,6 +88,9 @@ static int read_code(GetBitContext *gb, int *oskip, int *level, int *map, int mo
 {
     int len = 0, skip = 0, max;
 
+    if (get_bits_left(gb) < 2)
+        return AVERROR_INVALIDDATA;
+
     if (show_bits(gb, 2)) {
         switch (show_bits(gb, 4)) {
         case 1:
-- 
2.21.0