From a3bab162b2ae616074c8877a04556932998aeacd Mon Sep 17 00:00:00 2001
From: Werner Lemberg <wl@gnu.org>
Date: Mon, 19 Oct 2020 23:45:28 +0200
Subject: [sfnt] Fix heap buffer overflow (#59308).
 This is CVE-2020-15999.
 * src/sfnt/pngshim.c (Load_SBit_Png): Test bitmap size earlier.
reference：https://git.savannah.gnu.org/cgit/freetype/freetype2.git/commit/?id=a3bab162b2ae616074c8877a04556932998aeacd
---
 src/sfnt/pngshim.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/sfnt/pngshim.c b/src/sfnt/pngshim.c
index 523b30a..5502108 100644
--- a/src/sfnt/pngshim.c
+++ b/src/sfnt/pngshim.c
@@ -328,6 +328,13 @@
 
     if ( populate_map_and_metrics )
     {
+      /* reject too large bitmaps similarly to the rasterizer */
+      if ( imgHeight > 0x7FFF || imgWidth > 0x7FFF )
+      {
+        error = FT_THROW( Array_Too_Large );
+        goto DestroyExit;
+      }
+
       metrics->width  = (FT_UShort)imgWidth;
       metrics->height = (FT_UShort)imgHeight;
 
@@ -336,13 +343,6 @@
       map->pixel_mode = FT_PIXEL_MODE_BGRA;
       map->pitch      = (int)( map->width * 4 );
       map->num_grays  = 256;
-
-      /* reject too large bitmaps similarly to the rasterizer */
-      if ( map->rows > 0x7FFF || map->width > 0x7FFF )
-      {
-        error = FT_THROW( Array_Too_Large );
-        goto DestroyExit;
-      }
     }
 
     /* convert palette/gray image to rgb */
-- 
2.27.0