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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-03-10 01:40:59 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-03-14 00:24:44 +0100 |
| commit | 1e50a327c649c8a00741996b9f6db83fdc00285a (patch) | |
| tree | 0d63723cf7786a1091c844b3da7ba471cdcfb0ff | |
| parent | ad12d9df1ed939e47cccc832ca4c363e68374adc (diff) | |
| download | ffmpeg-1e50a327c649c8a00741996b9f6db83fdc00285a.tar.gz | |
avcodec/mpeg4videodec: Check idx in mpeg4_decode_studio_block()
Fixes: Out of array access
Fixes: 13500/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-5769760178962432
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Kieran Kunhya <kierank@obe.tv>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit d227ed5d598340e719eff7156b1aa0a4469e9a6a)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/mpeg4videodec.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index ecd028a87c..bb9f1e3f2c 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -1899,14 +1899,20 @@ static int mpeg4_decode_studio_block(MpegEncContext *s, int32_t block[64], int n code >>= 1; run = (1 << (additional_code_len - 1)) + code; idx += run; + if (idx > 63) + return AVERROR_INVALIDDATA; j = scantable[idx++]; block[j] = sign ? 1 : -1; } else if (group >= 13 && group <= 20) { /* Level value (Table B.49) */ + if (idx > 63) + return AVERROR_INVALIDDATA; j = scantable[idx++]; block[j] = get_xbits(&s->gb, additional_code_len); } else if (group == 21) { /* Escape */ + if (idx > 63) + return AVERROR_INVALIDDATA; j = scantable[idx++]; additional_code_len = s->avctx->bits_per_raw_sample + s->dct_precision + 4; flc = get_bits(&s->gb, additional_code_len); |