I do not know if such vlc trees are allowed in agm, I have no specification
So i do not know if these should be treated as error, or not.
But the code does contain a check for idx < 0 already ...
Fixes: Stack-buffer-overflow in get_tree_codes Fixes: 14189/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AGM_fuzzer-5745747003179008 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Reviewed-by: Paul B Mahol <onemda@gmail.com> Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>