avcodec/mpeg12dec: Fix runtime error: left shift of negative value -2

671/clusterfuzz-testcase-4990381827555328

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-02-25 21:07:24 +01:00
parent 0716bcce5b
commit aff8cf18cb

View File

@ -948,8 +948,8 @@ static int mpeg_decode_mb(MpegEncContext *s, int16_t block[12][64])
dmy = get_dmv(s);
s->last_mv[i][0][1] = my << my_shift;
s->last_mv[i][1][1] = my << my_shift;
s->last_mv[i][0][1] = my * (1 << my_shift);
s->last_mv[i][1][1] = my * (1 << my_shift);
s->mv[i][0][0] = mx;
s->mv[i][0][1] = my;