From: Zhang Boyang <zhangboyang.id@gmail.com>
Date: Mon, 5 Dec 2022 11:29:38 +0000 (+0800)
Subject: font: Reject fonts with negative max_char_width or max_char_height
X-Git-Tag: grub-2.12-rc1~182
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=faca60df7686a9a3ad9693e8a7b2c6a3a823d133;p=thirdparty%2Fgrub.git

font: Reject fonts with negative max_char_width or max_char_height

If max_char_width or max_char_height are negative wrong values can be propagated
by grub_font_get_max_char_width() or grub_font_get_max_char_height(). Prevent
this from happening.

Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---

diff --git a/grub-core/font/font.c b/grub-core/font/font.c
index 674043d0d..24adcb35a 100644
--- a/grub-core/font/font.c
+++ b/grub-core/font/font.c
@@ -644,8 +644,8 @@ grub_font_load (const char *filename)
 	       font->max_char_width, font->max_char_height, font->num_chars);
 #endif
 
-  if (font->max_char_width == 0
-      || font->max_char_height == 0
+  if (font->max_char_width <= 0
+      || font->max_char_height <= 0
       || font->num_chars == 0
       || font->char_index == 0 || font->ascent == 0 || font->descent == 0)
     {