From d7ed2ebcd69df123fde8ae1ba9163e2b93c47bbf Mon Sep 17 00:00:00 2001
From: Zhang Boyang <zhangboyang.id@gmail.com>
Date: Mon, 5 Dec 2022 19:29:36 +0800
Subject: 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.

Reference:https://git.savannah.gnu.org/cgit/grub.git/commit?id=d7ed2ebcd69df123fde8ae1ba9163e2b93c47bbf
Conflict:NA

Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 grub-core/font/font.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/grub-core/font/font.c b/grub-core/font/font.c
index 3821937..19a47f8 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;
-- 
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