From 830a9628b2c9e1b6388af624aaf4a80818ed6be0 Mon Sep 17 00:00:00 2001

From: Daniel Axtens <dja@axtens.net>

Date: Tue, 13 Jul 2021 13:24:38 +1000

Subject: [PATCH] normal/charset: Fix array out-of-bounds formatting unicode

 for display

In some cases attempting to display arbitrary binary strings leads

to ASAN splats reading the widthspec array out of bounds.

Check the index. If it would be out of bounds, return a width of 1.

I don't know if that's strictly correct, but we're not really expecting

great display of arbitrary binary data, and it's certainly not worse than

an OOB read.

Signed-off-by: Daniel Axtens <dja@axtens.net>

Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

---

 grub-core/normal/charset.c | 2 ++

 1 file changed, 2 insertions(+)

diff --git a/grub-core/normal/charset.c b/grub-core/normal/charset.c

index 7778f1a99..000e687bd 100644

--- a/grub-core/normal/charset.c

+++ b/grub-core/normal/charset.c

@@ -395,6 +395,8 @@ grub_unicode_estimate_width (const struct grub_unicode_glyph *c)

 {

   if (grub_unicode_get_comb_type (c->base))

     return 0;

+  if (((unsigned long) (c->base >> 3)) >= ARRAY_SIZE (widthspec))

+    return 1;

   if (widthspec[c->base >> 3] & (1 << (c->base & 7)))

     return 2;

   else

-- 

2.33.5