File ffmpeg-CVE-2020-22020.patch of Package ffmpeg.28802

From ce5274c1385d55892a692998923802023526b765 Mon Sep 17 00:00:00 2001
From: Paul B Mahol <onemda@gmail.com>
Date: Sat, 19 Oct 2019 11:56:02 +0200
Subject: [PATCH] avfilter/vf_fieldmatch: fix heap-buffer overflow

Also fix use of uninitialized values.

Fixes #8239
---
 libavfilter/vf_fieldmatch.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavfilter/vf_fieldmatch.c b/libavfilter/vf_fieldmatch.c
index d115229e53..fa4aa8239c 100644
--- a/libavfilter/vf_fieldmatch.c
+++ b/libavfilter/vf_fieldmatch.c
@@ -950,7 +950,7 @@ static int config_input(AVFilterLink *inlink)
     fm->tpitchy  = FFALIGN(w,      16);
     fm->tpitchuv = FFALIGN(w >> 1, 16);
 
-    fm->tbuffer = av_malloc(h/2 * fm->tpitchy);
+    fm->tbuffer = av_calloc((h/2 + 4) * fm->tpitchy, sizeof(*fm->tbuffer));
     fm->c_array = av_malloc((((w + fm->blockx/2)/fm->blockx)+1) *
                             (((h + fm->blocky/2)/fm->blocky)+1) *
                             4 * sizeof(*fm->c_array));
-- 
2.31.1