From ced9a1cd0ab76a65e509b0d7c56965d61ea1df84 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 10 Sep 2019 18:57:25 +0200 Subject: [PATCH] avcodec/vc1_pred: Fix invalid shifts in scaleforopp() Fixes: left shift of negative value -2 Fixes: 16964/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VC1IMAGE_fuzzer-5757853565976576 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/vc1_pred.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libavcodec/vc1_pred.c b/libavcodec/vc1_pred.c index e1ad0e1d7d..f70956e739 100644 --- a/libavcodec/vc1_pred.c +++ b/libavcodec/vc1_pred.c @@ -191,9 +191,9 @@ static av_always_inline int scaleforopp(VC1Context *v, int n /* MV */, n >>= hpel; if (v->s.pict_type == AV_PICTURE_TYPE_B && !v->second_field && dir == 1) { if (dim) - n = scaleforopp_y(v, n, dir) << hpel; + n = scaleforopp_y(v, n, dir) * (1 << hpel); else - n = scaleforopp_x(v, n) << hpel; + n = scaleforopp_x(v, n) * (1 << hpel); return n; } if (v->s.pict_type != AV_PICTURE_TYPE_B)