kumquat-buildroot/boot/grub2/0016-font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch
Thomas Petazzoni 65c99394ff boot/grub2: backport fixes for numerous CVEs
Grub 2.06 is affected by a number of CVEs, which have been fixed in
the master branch of Grub, but are not yet part of any release (there
is a 2.12-rc1 release, but nothing else between 2.06 and 2.12-rc1).

So this patch backports the relevant fixes for CVE-2022-28736,
CVE-2022-28735, CVE-2021-3695, CVE-2021-3696, CVE-2021-3697,
CVE-2022-28733, CVE-2022-28734, CVE-2022-2601 and CVE-2022-3775.

It should be noted that CVE-2021-3695, CVE-2021-3696, CVE-2021-3697
are not reported as affecting Grub by our CVE matching logic because
the NVD database uses an incorrect CPE ID in those CVEs: it uses
"grub" as the product instead of "grub2" like all other CVEs for
grub. This issue has been reported to the NVD maintainers.

This requires backporting a lot of patches, but jumping from 2.06 to
2.12-rc1 implies getting 592 commits, which is quite a lot.

All Grub test cases are working fine:

  https://gitlab.com/tpetazzoni/buildroot/-/pipelines/984500585
  https://gitlab.com/tpetazzoni/buildroot/-/pipelines/984500679

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[Arnout: fix check-package warning in patch 0002]
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>
2023-08-30 21:54:23 +02:00

117 lines
4.1 KiB
Diff

From 1aefeca0f6304a20c1a3711cb9e89c5fdb901b6b Mon Sep 17 00:00:00 2001
From: Zhang Boyang <zhangboyang.id@gmail.com>
Date: Fri, 5 Aug 2022 00:51:20 +0800
Subject: [PATCH] font: Fix size overflow in grub_font_get_glyph_internal()
The length of memory allocation and file read may overflow. This patch
fixes the problem by using safemath macros.
There is a lot of code repetition like "(x * y + 7) / 8". It is unsafe
if overflow happens. This patch introduces grub_video_bitmap_calc_1bpp_bufsz().
It is safe replacement for such code. It has safemath-like prototype.
This patch also introduces grub_cast(value, pointer), it casts value to
typeof(*pointer) then store the value to *pointer. It returns true when
overflow occurs or false if there is no overflow. The semantics of arguments
and return value are designed to be consistent with other safemath macros.
Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Upstream: 9c76ec09ae08155df27cd237eaea150b4f02f532
[Thomas: needed to backport 768e1ef2fc159f6e14e7246e4be09363708ac39e,
which fixes CVE-2022-2601]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
---
grub-core/font/font.c | 17 +++++++++++++----
include/grub/bitmap.h | 18 ++++++++++++++++++
include/grub/safemath.h | 2 ++
3 files changed, 33 insertions(+), 4 deletions(-)
diff --git a/grub-core/font/font.c b/grub-core/font/font.c
index d09bb38d8..876b5b695 100644
--- a/grub-core/font/font.c
+++ b/grub-core/font/font.c
@@ -739,7 +739,8 @@ grub_font_get_glyph_internal (grub_font_t font, grub_uint32_t code)
grub_int16_t xoff;
grub_int16_t yoff;
grub_int16_t dwidth;
- int len;
+ grub_ssize_t len;
+ grub_size_t sz;
if (index_entry->glyph)
/* Return cached glyph. */
@@ -766,9 +767,17 @@ grub_font_get_glyph_internal (grub_font_t font, grub_uint32_t code)
return 0;
}
- len = (width * height + 7) / 8;
- glyph = grub_malloc (sizeof (struct grub_font_glyph) + len);
- if (!glyph)
+ /* Calculate real struct size of current glyph. */
+ if (grub_video_bitmap_calc_1bpp_bufsz (width, height, &len) ||
+ grub_add (sizeof (struct grub_font_glyph), len, &sz))
+ {
+ remove_font (font);
+ return 0;
+ }
+
+ /* Allocate and initialize the glyph struct. */
+ glyph = grub_malloc (sz);
+ if (glyph == NULL)
{
remove_font (font);
return 0;
diff --git a/include/grub/bitmap.h b/include/grub/bitmap.h
index 5728f8ca3..0d9603f61 100644
--- a/include/grub/bitmap.h
+++ b/include/grub/bitmap.h
@@ -23,6 +23,7 @@
#include <grub/symbol.h>
#include <grub/types.h>
#include <grub/video.h>
+#include <grub/safemath.h>
struct grub_video_bitmap
{
@@ -79,6 +80,23 @@ grub_video_bitmap_get_height (struct grub_video_bitmap *bitmap)
return bitmap->mode_info.height;
}
+/*
+ * Calculate and store the size of data buffer of 1bit bitmap in result.
+ * Equivalent to "*result = (width * height + 7) / 8" if no overflow occurs.
+ * Return true when overflow occurs or false if there is no overflow.
+ * This function is intentionally implemented as a macro instead of
+ * an inline function. Although a bit awkward, it preserves data types for
+ * safemath macros and reduces macro side effects as much as possible.
+ *
+ * XXX: Will report false overflow if width * height > UINT64_MAX.
+ */
+#define grub_video_bitmap_calc_1bpp_bufsz(width, height, result) \
+({ \
+ grub_uint64_t _bitmap_pixels; \
+ grub_mul ((width), (height), &_bitmap_pixels) ? 1 : \
+ grub_cast (_bitmap_pixels / GRUB_CHAR_BIT + !!(_bitmap_pixels % GRUB_CHAR_BIT), (result)); \
+})
+
void EXPORT_FUNC (grub_video_bitmap_get_mode_info) (struct grub_video_bitmap *bitmap,
struct grub_video_mode_info *mode_info);
diff --git a/include/grub/safemath.h b/include/grub/safemath.h
index c17b89bba..bb0f826de 100644
--- a/include/grub/safemath.h
+++ b/include/grub/safemath.h
@@ -30,6 +30,8 @@
#define grub_sub(a, b, res) __builtin_sub_overflow(a, b, res)
#define grub_mul(a, b, res) __builtin_mul_overflow(a, b, res)
+#define grub_cast(a, res) grub_add ((a), 0, (res))
+
#else
#error gcc 5.1 or newer or clang 3.8 or newer is required
#endif
--
2.41.0