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| author | Michael Niedermayer <michael@niedermayer.cc> | 2019-07-11 20:02:24 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2020-07-01 12:11:55 +0200 |
| commit | 71100d7102f76686ee139d9f2cf9f400461c76dd (patch) | |
| tree | 8e023c6c8b10cae488da89cf95cd19ec70838140 | |
| parent | cea8e10a0fd26904933f3ca15d1bd967447437cd (diff) | |
| download | ffmpeg-71100d7102f76686ee139d9f2cf9f400461c76dd.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 8894457c7e..f5891a158d 100644 --- a/libavcodec/mpc8.c +++ b/libavcodec/mpc8.c @@ -362,8 +362,9 @@ 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: |