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poky/meta/recipes-bsp/grub/files/CVE-2022-3775.patch
Hitendra Prajapati 95649c2878 grub2: Fix CVE-2022-2601 & CVE-2022-3775
Backport patch from upstream to solve CVE-2022-2601 CVE-2022-3775 dependency:

font: Fix size overflow in grub_font_get_glyph_internal()
Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=9c76ec09ae08155df27cd237eaea150b4f02f532

CVE-2022-2601: font: Fix several integer overflows in grub_font_construct_glyph()
Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=768e1ef2fc159f6e14e7246e4be09363708ac39e

CVE-2022-3775: font: Fix an integer underflow in blit_comb()
Upstream-Status: Backport from https://git.savannah.gnu.org/cgit/grub.git/commit/?id=992c06191babc1e109caf40d6a07ec6fdef427af

(From OE-Core rev: 6149febd53b32406dc4b07b1721b3dfbae70723e)

Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
2023-01-13 18:11:19 +00:00

98 lines
4.2 KiB
Diff

From fdbe7209152ad6f09a1166f64f162017f2145ba3 Mon Sep 17 00:00:00 2001
From: Zhang Boyang <zhangboyang.id@gmail.com>
Date: Mon, 24 Oct 2022 08:05:35 +0800
Subject: [PATCH] font: Fix an integer underflow in blit_comb()
The expression (ctx.bounds.height - combining_glyphs[i]->height) / 2 may
evaluate to a very big invalid value even if both ctx.bounds.height and
combining_glyphs[i]->height are small integers. For example, if
ctx.bounds.height is 10 and combining_glyphs[i]->height is 12, this
expression evaluates to 2147483647 (expected -1). This is because
coordinates are allowed to be negative but ctx.bounds.height is an
unsigned int. So, the subtraction operates on unsigned ints and
underflows to a very big value. The division makes things even worse.
The quotient is still an invalid value even if converted back to int.
This patch fixes the problem by casting ctx.bounds.height to int. As
a result the subtraction will operate on int and grub_uint16_t which
will be promoted to an int. So, the underflow will no longer happen. Other
uses of ctx.bounds.height (and ctx.bounds.width) are also casted to int,
to ensure coordinates are always calculated on signed integers.
Fixes: CVE-2022-3775
Reported-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=992c06191babc1e109caf40d6a07ec6fdef427af]
CVE: CVE-2022-3775
Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com>
---
grub-core/font/font.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/grub-core/font/font.c b/grub-core/font/font.c
index f110db9..3b76b22 100644
--- a/grub-core/font/font.c
+++ b/grub-core/font/font.c
@@ -1200,12 +1200,12 @@ blit_comb (const struct grub_unicode_glyph *glyph_id,
ctx.bounds.height = main_glyph->height;
above_rightx = main_glyph->offset_x + main_glyph->width;
- above_righty = ctx.bounds.y + ctx.bounds.height;
+ above_righty = ctx.bounds.y + (int) ctx.bounds.height;
above_leftx = main_glyph->offset_x;
- above_lefty = ctx.bounds.y + ctx.bounds.height;
+ above_lefty = ctx.bounds.y + (int) ctx.bounds.height;
- below_rightx = ctx.bounds.x + ctx.bounds.width;
+ below_rightx = ctx.bounds.x + (int) ctx.bounds.width;
below_righty = ctx.bounds.y;
comb = grub_unicode_get_comb (glyph_id);
@@ -1218,7 +1218,7 @@ blit_comb (const struct grub_unicode_glyph *glyph_id,
if (!combining_glyphs[i])
continue;
- targetx = (ctx.bounds.width - combining_glyphs[i]->width) / 2 + ctx.bounds.x;
+ targetx = ((int) ctx.bounds.width - combining_glyphs[i]->width) / 2 + ctx.bounds.x;
/* CGJ is to avoid diacritics reordering. */
if (comb[i].code
== GRUB_UNICODE_COMBINING_GRAPHEME_JOINER)
@@ -1228,8 +1228,8 @@ blit_comb (const struct grub_unicode_glyph *glyph_id,
case GRUB_UNICODE_COMB_OVERLAY:
do_blit (combining_glyphs[i],
targetx,
- (ctx.bounds.height - combining_glyphs[i]->height) / 2
- - (ctx.bounds.height + ctx.bounds.y), &ctx);
+ ((int) ctx.bounds.height - combining_glyphs[i]->height) / 2
+ - ((int) ctx.bounds.height + ctx.bounds.y), &ctx);
if (min_devwidth < combining_glyphs[i]->width)
min_devwidth = combining_glyphs[i]->width;
break;
@@ -1302,7 +1302,7 @@ blit_comb (const struct grub_unicode_glyph *glyph_id,
/* Fallthrough. */
case GRUB_UNICODE_STACK_ATTACHED_ABOVE:
do_blit (combining_glyphs[i], targetx,
- -(ctx.bounds.height + ctx.bounds.y + space
+ -((int) ctx.bounds.height + ctx.bounds.y + space
+ combining_glyphs[i]->height), &ctx);
if (min_devwidth < combining_glyphs[i]->width)
min_devwidth = combining_glyphs[i]->width;
@@ -1310,7 +1310,7 @@ blit_comb (const struct grub_unicode_glyph *glyph_id,
case GRUB_UNICODE_COMB_HEBREW_DAGESH:
do_blit (combining_glyphs[i], targetx,
- -(ctx.bounds.height / 2 + ctx.bounds.y
+ -((int) ctx.bounds.height / 2 + ctx.bounds.y
+ combining_glyphs[i]->height / 2), &ctx);
if (min_devwidth < combining_glyphs[i]->width)
min_devwidth = combining_glyphs[i]->width;
--
2.25.1