File ffmpeg-CVE-2020-22021.patch of Package ffmpeg.21291

diff --unified --recursive --text --new-file --color ffmpeg-3.4.2.old/libavfilter/vf_yadif.c ffmpeg-3.4.2.new/libavfilter/vf_yadif.c
--- ffmpeg-3.4.2.old/libavfilter/vf_yadif.c	2021-06-02 15:52:46.082175501 +0800
+++ ffmpeg-3.4.2.new/libavfilter/vf_yadif.c	2021-06-09 10:16:04.055240754 +0800
@@ -123,19 +123,23 @@
     uint8_t *prev2 = parity ? prev : cur ;
     uint8_t *next2 = parity ? cur  : next;
 
+    const int edge = MAX_ALIGN - 1;
+    int offset = FFMAX(w - edge, 3);
+
     /* Only edge pixels need to be processed here.  A constant value of false
      * for is_not_edge should let the compiler ignore the whole branch. */
-    FILTER(0, 3, 0)
+    FILTER(0, FFMIN(3, w), 0)
 
-    dst  = (uint8_t*)dst1  + w - (MAX_ALIGN-1);
-    prev = (uint8_t*)prev1 + w - (MAX_ALIGN-1);
-    cur  = (uint8_t*)cur1  + w - (MAX_ALIGN-1);
-    next = (uint8_t*)next1 + w - (MAX_ALIGN-1);
+    dst  = (uint8_t*)dst1  + offset;
+    prev = (uint8_t*)prev1 + offset;
+    cur  = (uint8_t*)cur1  + offset;
+    next = (uint8_t*)next1 + offset;
     prev2 = (uint8_t*)(parity ? prev : cur);
     next2 = (uint8_t*)(parity ? cur  : next);
 
-    FILTER(w - (MAX_ALIGN-1), w - 3, 1)
-    FILTER(w - 3, w, 0)
+    FILTER(offset, w - 3, 1)
+    offset = FFMAX(offset, w - 3);
+    FILTER(offset, w, 0)
 }
 
 
@@ -167,20 +171,25 @@
     int x;
     uint16_t *prev2 = parity ? prev : cur ;
     uint16_t *next2 = parity ? cur  : next;
+
+    const int edge = MAX_ALIGN / 2 - 1;
+    int offset = FFMAX(w - edge, 3);
+
     mrefs /= 2;
     prefs /= 2;
 
-    FILTER(0, 3, 0)
+    FILTER(0,  FFMIN(3, w), 0)
 
-    dst   = (uint16_t*)dst1  + w - (MAX_ALIGN/2-1);
-    prev  = (uint16_t*)prev1 + w - (MAX_ALIGN/2-1);
-    cur   = (uint16_t*)cur1  + w - (MAX_ALIGN/2-1);
-    next  = (uint16_t*)next1 + w - (MAX_ALIGN/2-1);
+    dst   = (uint16_t*)dst1  + offset;
+    prev  = (uint16_t*)prev1 + offset;
+    cur   = (uint16_t*)cur1  + offset;
+    next  = (uint16_t*)next1 + offset;
     prev2 = (uint16_t*)(parity ? prev : cur);
     next2 = (uint16_t*)(parity ? cur  : next);
 
-    FILTER(w - (MAX_ALIGN/2-1), w - 3, 1)
-    FILTER(w - 3, w, 0)
+    FILTER(offset, w - 3, 1)
+    offset = FFMAX(offset, w - 3);
+    FILTER(offset, w, 0)
 }
 
 static int filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)