integ/grub/grub2/debian/patches/0011-font-Fix-integer-underflow-in-binary-search-of-char-.patch
Li Zhou d10d6fb187 grub2/grub-efi: fix CVE-2022-2601/CVE-2022-3775
Porting patches from grub2_2.06-3~deb11u4 to fix
CVE-2022-2601/CVE-2022-3775.

The source code of grub2_2.06-3~deb11u4 is from:
https://snapshot.debian.org/archive/debian/20221124T030451Z/
pool/main/g/grub2/grub2_2.06-3~deb11u4.debian.tar.xz

Refer to above source code and this link for the fix:
https://lists.gnu.org/archive/html/grub-devel/2022-11/msg00059.html

The 1st patch in the list is for making proper context for the 14
patches of the 2 CVEs. No content changes for all the patches from
debian release.

We do this because grub2/grub-efi is ported from wrlinux for
secure boot bringing up.

Test plan:
 - PASS: build grub2/grub-efi.
 - PASS: build-image and install and boot up on lab/qemu.
 - PASS: check that the "stx.N" version number is right for both
         bios(grub2 ver) and uefi(grub-efi ver) boot.

Closes-bug: 2020730

Signed-off-by: Li Zhou <li.zhou@windriver.com>
Change-Id: Ia6c58a2021a786ef92f760b3cfe035fbccedacf7
2023-06-01 06:08:44 -04:00

87 lines
2.4 KiB
Diff

From c140a086838e7c9af87842036f891b8393a8c4bc Mon Sep 17 00:00:00 2001
From: Zhang Boyang <zhangboyang.id@gmail.com>
Date: Sun, 14 Aug 2022 18:09:38 +0800
Subject: [PATCH 08/14] font: Fix integer underflow in binary search of char
index
If search target is less than all entries in font->index then "hi"
variable is set to -1, which translates to SIZE_MAX and leads to errors.
This patch fixes the problem by replacing the entire binary search code
with the libstdc++'s std::lower_bound() implementation.
Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
grub-core/font/font.c | 40 ++++++++++++++++++++++------------------
1 file changed, 22 insertions(+), 18 deletions(-)
diff --git a/grub-core/font/font.c b/grub-core/font/font.c
index e4cb0d867..abd412a5e 100644
--- a/grub-core/font/font.c
+++ b/grub-core/font/font.c
@@ -688,12 +688,12 @@ read_be_int16 (grub_file_t file, grub_int16_t * value)
static inline struct char_index_entry *
find_glyph (const grub_font_t font, grub_uint32_t code)
{
- struct char_index_entry *table;
- grub_size_t lo;
- grub_size_t hi;
- grub_size_t mid;
+ struct char_index_entry *table, *first, *end;
+ grub_size_t len;
table = font->char_index;
+ if (table == NULL)
+ return NULL;
/* Use BMP index if possible. */
if (code < 0x10000 && font->bmp_idx)
@@ -706,25 +706,29 @@ find_glyph (const grub_font_t font, grub_uint32_t code)
*/
}
- /* Do a binary search in `char_index', which is ordered by code point. */
- lo = 0;
- hi = font->num_chars - 1;
-
- if (!table)
- return 0;
+ /*
+ * Do a binary search in char_index which is ordered by code point.
+ * The code below is the same as libstdc++'s std::lower_bound().
+ */
+ first = table;
+ len = font->num_chars;
+ end = first + len;
- while (lo <= hi)
+ while (len > 0)
{
- mid = lo + (hi - lo) / 2;
- if (code < table[mid].code)
- hi = mid - 1;
- else if (code > table[mid].code)
- lo = mid + 1;
+ grub_size_t half = len >> 1;
+ struct char_index_entry *middle = first + half;
+
+ if (middle->code < code)
+ {
+ first = middle + 1;
+ len = len - half - 1;
+ }
else
- return &table[mid];
+ len = half;
}
- return 0;
+ return (first < end && first->code == code) ? first : NULL;
}
/* Get a glyph for the Unicode character CODE in FONT. The glyph is loaded
--
2.30.2