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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-08-23 00:23:52 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2020-01-06 11:30:43 +0100 |
| commit | 12e035b6fa1c7e00886245bbf74b94817034493c (patch) | |
| tree | 4cda40e56d12d9784a6e2affc1bfb5fc7b581804 | |
| parent | 77c60f16d7fc1245f2852c07486909e3df8a0bcf (diff) | |
| download | ffmpeg-12e035b6fa1c7e00886245bbf74b94817034493c.tar.gz | |
avcodec/mpeg4videodec: Fix integer overflow in mpeg4_decode_studio_block()
Fixes: signed integer overflow: 24023040 * 112 cannot be represented in type 'int'
Fixes: 16570/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG4_fuzzer-5173275211071488
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 0e4a0e962cb0e422d2a350b875fc1e38d7b842a3)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/mpeg4videodec.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c index bb9f1e3f2c..fd68295ee4 100644 --- a/libavcodec/mpeg4videodec.c +++ b/libavcodec/mpeg4videodec.c @@ -1826,6 +1826,7 @@ static int mpeg4_decode_studio_block(MpegEncContext *s, int32_t block[64], int n uint32_t flc; const int min = -1 * (1 << (s->avctx->bits_per_raw_sample + 6)); const int max = ((1 << (s->avctx->bits_per_raw_sample + 6)) - 1); + int shift = 3 - s->dct_precision; mismatch = 1; @@ -1921,7 +1922,7 @@ static int mpeg4_decode_studio_block(MpegEncContext *s, int32_t block[64], int n else block[j] = flc; } - block[j] = ((8 * 2 * block[j] * quant_matrix[j] * s->qscale) >> s->dct_precision) / 32; + block[j] = ((block[j] * quant_matrix[j] * s->qscale) * (1 << shift)) / 16; block[j] = av_clip(block[j], min, max); mismatch ^= block[j]; } |