avcodec/4xm: Check for end of input in decode_p_block()

Fixes: Timeout (81sec -> 0.2sec)
Fixes: 16169/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FOURXM_fuzzer-5662570416963584

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>
This commit is contained in:
Michael Niedermayer 2019-08-12 02:17:18 +02:00
parent 021f29506b
commit 8f92eb05e0

View File

@ -351,6 +351,8 @@ static int decode_p_block(FourXContext *f, uint16_t *dst, const uint16_t *src,
index = size2index[log2h][log2w];
av_assert0(index >= 0);
if (get_bits_left(&f->gb) < 1)
return AVERROR_INVALIDDATA;
h = 1 << log2h;
code = get_vlc2(&f->gb, block_type_vlc[1 - (f->version > 1)][index].table,
BLOCK_TYPE_VLC_BITS, 1);