From d782b0b2ada3468dabb265f981807aa35751ea7a Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 25 Feb 2017 21:07:24 +0100 Subject: [PATCH] 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 Signed-off-by: Michael Niedermayer (cherry picked from commit aff8cf18cb0b1fa4f2e3d163c3da2f25aa6d1906) Signed-off-by: Michael Niedermayer --- libavcodec/mpeg12dec.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/mpeg12dec.c b/libavcodec/mpeg12dec.c index 032edbf6d4..ec1b86a558 100644 --- a/libavcodec/mpeg12dec.c +++ b/libavcodec/mpeg12dec.c @@ -1003,8 +1003,8 @@ 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;