From f6b6236077f059e64ee315f2d7acb8fa4eda87c5 Mon Sep 17 00:00:00 2001
From: Zhang Boyang <zhangboyang.id@gmail.com>
Date: Wed, 3 Aug 2022 19:45:33 +0800
Subject: [PATCH 01/13] font: Reject glyphs exceeds font->max_glyph_width or
 font->max_glyph_height

Check glyph's width and height against limits specified in font's
metadata. Reject the glyph (and font) if such limits are exceeded.

Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/font/font.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/grub-core/font/font.c b/grub-core/font/font.c
index 42189c325..756ca0abf 100644
--- a/grub-core/font/font.c
+++ b/grub-core/font/font.c
@@ -760,7 +760,9 @@ grub_font_get_glyph_internal (grub_font_t font, grub_uint32_t code)
 	  || read_be_uint16 (font->file, &height) != 0
 	  || read_be_int16 (font->file, &xoff) != 0
 	  || read_be_int16 (font->file, &yoff) != 0
-	  || read_be_int16 (font->file, &dwidth) != 0)
+	  || read_be_int16 (font->file, &dwidth) != 0
+	  || width > font->max_char_width
+	  || height > font->max_char_height)
 	{
 	  remove_font (font);
 	  return 0;
-- 
2.27.0