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| author | Michael Niedermayer <michael@niedermayer.cc> | 2020-07-23 23:41:27 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2020-07-24 22:34:15 +0200 |
| commit | 4333718b357a9ad195031e5d0ea080d37677b795 (patch) | |
| tree | 1417c943981201ede0621f9d85a6d178cf3d21cd | |
| parent | 21442a820aec365fc298d9a89d564db7ef866d86 (diff) | |
| download | ffmpeg-4333718b357a9ad195031e5d0ea080d37677b795.tar.gz | |
avcodec/alac: Check decorr_shift to avoid invalid shift
Later the decorrelate_stereo call is guarded by channels == 2
and non-zero decorr_left_weight. Make sure decorr_shift is in
the expected shift range for that case.
Fixes: shift exponent 128 is too large for 32-bit type 'int'
Fixes: 23860/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ALAC_fuzzer-5751138914402304
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Alexander Strasser <eclipse7@gmx.net>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/alac.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/libavcodec/alac.c b/libavcodec/alac.c index bf05406230..9040673528 100644 --- a/libavcodec/alac.c +++ b/libavcodec/alac.c @@ -302,6 +302,9 @@ static int decode_element(AVCodecContext *avctx, AVFrame *frame, int ch_index, decorr_shift = get_bits(&alac->gb, 8); decorr_left_weight = get_bits(&alac->gb, 8); + if (channels == 2 && decorr_left_weight && decorr_shift > 31) + return AVERROR_INVALIDDATA; + for (ch = 0; ch < channels; ch++) { prediction_type[ch] = get_bits(&alac->gb, 4); lpc_quant[ch] = get_bits(&alac->gb, 4); |