From: Zhang Boyang <zhangboyang.id@gmail.com>
Date: Mon, 5 Dec 2022 11:29:36 +0000 (+0800)
Subject: font: Check return value of grub_malloc() in ascii_glyph_lookup()
X-Git-Tag: grub-2.12-rc1~184
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d7ed2ebcd69df123fde8ae1ba9163e2b93c47bbf;p=thirdparty%2Fgrub.git

font: Check return value of grub_malloc() in ascii_glyph_lookup()

There is a problem in ascii_glyph_lookup(). It doesn't check the return
value of grub_malloc(). If memory can't be allocated, then NULL pointer
will be written to.

This patch fixes the problem by fallbacking to unknown_glyph when
grub_malloc() returns NULL.

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 3821937e6..19a47f873 100644
--- a/grub-core/font/font.c
+++ b/grub-core/font/font.c
@@ -131,6 +131,11 @@ ascii_glyph_lookup (grub_uint32_t code)
 	{
 	  ascii_font_glyph[current] =
 	    grub_malloc (sizeof (struct grub_font_glyph) + ASCII_BITMAP_SIZE);
+	  if (ascii_font_glyph[current] == NULL)
+	    {
+	      ascii_font_glyph[current] = unknown_glyph;
+	      continue;
+	    }
 
 	  ascii_font_glyph[current]->width = 8;
 	  ascii_font_glyph[current]->height = 16;