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| author | Michael Niedermayer <michael@niedermayer.cc> | 2017-07-26 20:10:28 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michael@niedermayer.cc> | 2017-07-28 03:40:59 +0200 |
| commit | aadfec7d6ca9b56b2bc0e24fa0aa4a29e301d664 (patch) | |
| tree | 0ef161b03c7c2e0306b51a592a59f0478f4247db | |
| parent | 47c0626ec721749b28df1c61c481e318e50058e4 (diff) | |
| download | ffmpeg-aadfec7d6ca9b56b2bc0e24fa0aa4a29e301d664.tar.gz | |
avcodec/pixlet: Simplify nbits computation
Fixes multiple integer overflows
Fixes: runtime error: signed integer overflow: 1 + 2147483647 cannot be represented in type 'int'
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit aeddb3607be94b1d6fef41b602b07f08223ea565)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
| -rw-r--r-- | libavcodec/pixlet.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/libavcodec/pixlet.c b/libavcodec/pixlet.c index 0e541a9ccb..a9661d3ab6 100644 --- a/libavcodec/pixlet.c +++ b/libavcodec/pixlet.c @@ -206,8 +206,8 @@ static int read_high_coeffs(AVCodecContext *avctx, uint8_t *src, int16_t *dst, i if ((ret = init_get_bits8(b, src, bytestream2_get_bytes_left(&ctx->gb))) < 0) return ret; - if ((a >= 0) + (a ^ (a >> 31)) - (a >> 31) != 1) { - nbits = 33 - ff_clz((a >= 0) + (a ^ (a >> 31)) - (a >> 31) - 1); + if (a ^ (a >> 31)) { + nbits = 33 - ff_clz(a ^ (a >> 31)); if (nbits > 16) return AVERROR_INVALIDDATA; } else { |