From fff5140620c52db3b7ebca5921d1d237b1dcc7ae Mon Sep 17 00:00:00 2001
From: Daniel Kiper <daniel.kiper@oracle.com>
Date: Tue, 7 Jul 2020 15:36:26 +0200
Subject: [PATCH 305/336] font: Do not load more than one NAME section

The GRUB font file can have one NAME section only. Though if somebody
crafts a broken font file with many NAME sections and loads it then the
GRUB leaks memory. So, prevent against that by loading first NAME
section and failing in controlled way on following one.

Reported-by: Chris Coulson <chris.coulson@canonical.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Jan Setje-Eilers <jan.setjeeilers@oracle.com>
Upstream-commit-id: 482814113dc
---
 grub-core/font/font.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/grub-core/font/font.c b/grub-core/font/font.c
index 71d3f78b88a..5ff5f438b40 100644
--- a/grub-core/font/font.c
+++ b/grub-core/font/font.c
@@ -532,6 +532,12 @@ grub_font_load (const char *filename)
       if (grub_memcmp (section.name, FONT_FORMAT_SECTION_NAMES_FONT_NAME,
 		       sizeof (FONT_FORMAT_SECTION_NAMES_FONT_NAME) - 1) == 0)
 	{
+	  if (font->name != NULL)
+	    {
+	      grub_error (GRUB_ERR_BAD_FONT, "invalid font file: too many NAME sections");
+	      goto fail;
+	    }
+
 	  font->name = read_section_as_string (&section);
 	  if (!font->name)
 	    goto fail;
-- 
2.26.2