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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-07-11 20:02:24 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2019-11-11 20:18:46 +0100 |
| commit | 3e2017426713056b4153c7d6178e093f4c34b941 (patch) | |
| tree | 5295ba296bb93aa4e158d2978e2940cd668d5064 | |
| parent | ac8c0c5bd1e54ca3f7cd55cd8049f13267290e29 (diff) | |
| download | ffmpeg-3e2017426713056b4153c7d6178e093f4c34b941.tar.gz | |
avcodec/mpc8: Fixes invalid shift in mpc8_decode_frame()
Fixes: left shift of negative value -456
Fixes: 15561/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPC8_fuzzer-5758130404720640
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Suggested-by: James Almer <jamrial@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 1dbb67d39b21ed320edd2b1599b502518250cfd3)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/mpc8.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libavcodec/mpc8.c b/libavcodec/mpc8.c index 3be2f79a5a..d7baac2f04 100644 --- a/libavcodec/mpc8.c +++ b/libavcodec/mpc8.c @@ -364,8 +364,9 @@ static int mpc8_decode_frame(AVCodecContext * avctx, void *data, for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){ cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2); t = mpc8_get_mask(gb, 18, cnt); - for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1) - c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0; + for(k = 0; k < SAMPLES_PER_BAND / 2; k++) + c->Q[ch][off + j + k] = t & (1 << (SAMPLES_PER_BAND / 2 - k - 1)) + ? (get_bits1(gb) << 1) - 1 : 0; } break; case 2: |