Adding debian version 2.06-13+deb12u1.debian/2.06-13+deb12u1debian

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

14 files changed, 970 insertions, 0 deletions

diff --git a/debian/patches/cve_2022_2601/0001-video-readers-Add-artificial-limit-to-image-dimensio.patch b/debian/patches/cve_2022_2601/0001-video-readers-Add-artificial-limit-to-image-dimensio.patch
new file mode 100644
index 0000000..99c2f5a
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0001-video-readers-Add-artificial-limit-to-image-dimensio.patch
@@ -0,0 +1,109 @@
+From a85714545fe57a86d14ee231a4cd312158101d43 Mon Sep 17 00:00:00 2001
+From: Alec Brown <alec.r.brown@oracle.com>
+Date: Wed, 26 Oct 2022 20:16:44 -0400
+Subject: [PATCH 01/14] video/readers: Add artificial limit to image dimensions
+
+In grub-core/video/readers/jpeg.c, the height and width of a JPEG image don't
+have an upper limit for how big the JPEG image can be. In Coverity, this is
+getting flagged as an untrusted loop bound. This issue can also seen in PNG and
+TGA format images as well but Coverity isn't flagging it. To prevent this, the
+constant IMAGE_HW_MAX_PX is being added to include/grub/bitmap.h, which has
+a value of 16384, to act as an artificial limit and restrict the height and
+width of images. This value was picked as it is double the current max
+resolution size, which is 8K.
+
+Fixes: CID 292450
+
+Signed-off-by: Alec Brown <alec.r.brown@oracle.com>
+Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ docs/grub.texi                 | 3 ++-
+ grub-core/video/readers/jpeg.c | 6 +++++-
+ grub-core/video/readers/png.c  | 6 +++++-
+ grub-core/video/readers/tga.c  | 7 +++++++
+ include/grub/bitmap.h          | 2 ++
+ 5 files changed, 21 insertions(+), 3 deletions(-)
+
+diff --git a/docs/grub.texi b/docs/grub.texi
+index 0dbbdc374..2d6cd8358 100644
+--- a/docs/grub.texi
++++ b/docs/grub.texi
+@@ -1515,7 +1515,8 @@ resolution.  @xref{gfxmode}.
+ Set a background image for use with the @samp{gfxterm} graphical terminal.
+ The value of this option must be a file readable by GRUB at boot time, and
+ it must end with @file{.png}, @file{.tga}, @file{.jpg}, or @file{.jpeg}.
+-The image will be scaled if necessary to fit the screen.
++The image will be scaled if necessary to fit the screen. Image height and
++width will be restricted by an artificial limit of 16384.
+ 
+ @item GRUB_THEME
+ Set a theme for use with the @samp{gfxterm} graphical terminal.
+diff --git a/grub-core/video/readers/jpeg.c b/grub-core/video/readers/jpeg.c
+index 09596fbf5..ae634fd41 100644
+--- a/grub-core/video/readers/jpeg.c
++++ b/grub-core/video/readers/jpeg.c
+@@ -346,7 +346,11 @@ grub_jpeg_decode_sof (struct grub_jpeg_data *data)
+   data->image_height = grub_jpeg_get_word (data);
+   data->image_width = grub_jpeg_get_word (data);
+ 
+-  if ((!data->image_height) || (!data->image_width))
++  grub_dprintf ("jpeg", "image height: %d\n", data->image_height);
++  grub_dprintf ("jpeg", "image width: %d\n", data->image_width);
++
++  if ((!data->image_height) || (!data->image_width) ||
++      (data->image_height > IMAGE_HW_MAX_PX) || (data->image_width > IMAGE_HW_MAX_PX))
+     return grub_error (GRUB_ERR_BAD_FILE_TYPE, "jpeg: invalid image size");
+ 
+   cc = grub_jpeg_get_byte (data);
+diff --git a/grub-core/video/readers/png.c b/grub-core/video/readers/png.c
+index 7f2ba7849..3163e97bf 100644
+--- a/grub-core/video/readers/png.c
++++ b/grub-core/video/readers/png.c
+@@ -264,7 +264,11 @@ grub_png_decode_image_header (struct grub_png_data *data)
+   data->image_width = grub_png_get_dword (data);
+   data->image_height = grub_png_get_dword (data);
+ 
+-  if ((!data->image_height) || (!data->image_width))
++  grub_dprintf ("png", "image height: %d\n", data->image_height);
++  grub_dprintf ("png", "image width: %d\n", data->image_width);
++
++  if ((!data->image_height) || (!data->image_width) ||
++      (data->image_height > IMAGE_HW_MAX_PX) || (data->image_width > IMAGE_HW_MAX_PX))
+     return grub_error (GRUB_ERR_BAD_FILE_TYPE, "png: invalid image size");
+ 
+   color_bits = grub_png_get_byte (data);
+diff --git a/grub-core/video/readers/tga.c b/grub-core/video/readers/tga.c
+index a9ec3a1b6..9c35bf29d 100644
+--- a/grub-core/video/readers/tga.c
++++ b/grub-core/video/readers/tga.c
+@@ -340,6 +340,13 @@ grub_video_reader_tga (struct grub_video_bitmap **bitmap,
+   data.image_width = grub_le_to_cpu16 (data.hdr.image_width);
+   data.image_height = grub_le_to_cpu16 (data.hdr.image_height);
+ 
++  grub_dprintf ("tga", "image height: %d\n", data.image_height);
++  grub_dprintf ("tga", "image width: %d\n", data.image_width);
++
++  /* Check image height and width are within restrictions. */
++  if ((data.image_height > IMAGE_HW_MAX_PX) || (data.image_width > IMAGE_HW_MAX_PX))
++    return grub_error (GRUB_ERR_BAD_FILE_TYPE, "tga: invalid image size");
++
+   /* Check that bitmap encoding is supported.  */
+   switch (data.hdr.image_type)
+     {
+diff --git a/include/grub/bitmap.h b/include/grub/bitmap.h
+index 5728f8ca3..149d37bfe 100644
+--- a/include/grub/bitmap.h
++++ b/include/grub/bitmap.h
+@@ -24,6 +24,8 @@
+ #include <grub/types.h>
+ #include <grub/video.h>
+ 
++#define IMAGE_HW_MAX_PX		16384
++
+ struct grub_video_bitmap
+ {
+   /* Bitmap format description.  */
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0002-font-Reject-glyphs-exceeds-font-max_glyph_width-or-f.patch b/debian/patches/cve_2022_2601/0002-font-Reject-glyphs-exceeds-font-max_glyph_width-or-f.patch
new file mode 100644
index 0000000..7330e5a
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0002-font-Reject-glyphs-exceeds-font-max_glyph_width-or-f.patch
@@ -0,0 +1,33 @@
+From 5760fcfd466cc757540ea0d591bad6a08caeaa16 Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Wed, 3 Aug 2022 19:45:33 +0800
+Subject: [PATCH 02/14] font: Reject glyphs exceeds font->max_glyph_width or
+ font->max_glyph_height
+
+Check glyph's width and height against limits specified in font's
+metadata. Reject the glyph (and font) if such limits are exceeded.
+
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/font/font.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/grub-core/font/font.c b/grub-core/font/font.c
+index 42189c325..756ca0abf 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -760,7 +760,9 @@ grub_font_get_glyph_internal (grub_font_t font, grub_uint32_t code)
+ 	  || read_be_uint16 (font->file, &height) != 0
+ 	  || read_be_int16 (font->file, &xoff) != 0
+ 	  || read_be_int16 (font->file, &yoff) != 0
+-	  || read_be_int16 (font->file, &dwidth) != 0)
++	  || read_be_int16 (font->file, &dwidth) != 0
++	  || width > font->max_char_width
++	  || height > font->max_char_height)
+ 	{
+ 	  remove_font (font);
+ 	  return 0;
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0003-font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch b/debian/patches/cve_2022_2601/0003-font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch
new file mode 100644
index 0000000..46ccb00
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0003-font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch
@@ -0,0 +1,110 @@
+From 941d10ad6f1dcbd12fb613002249e29ba035f985 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 03/14] 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>
+---
+ 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 2f09a4a55..6a3fbebbd 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.  */
+@@ -768,9 +769,17 @@ 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 149d37bfe..431048936 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>
+ 
+ #define IMAGE_HW_MAX_PX		16384
+ 
+@@ -81,6 +82,23 @@ 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
diff --git a/debian/patches/cve_2022_2601/0004-font-Fix-several-integer-overflows-in-grub_font_cons.patch b/debian/patches/cve_2022_2601/0004-font-Fix-several-integer-overflows-in-grub_font_cons.patch
new file mode 100644
index 0000000..9d3c9b2
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0004-font-Fix-several-integer-overflows-in-grub_font_cons.patch
@@ -0,0 +1,81 @@
+From b1805f251b31a9d3cfae5c3572ddfa630145dbbf Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Fri, 5 Aug 2022 01:58:27 +0800
+Subject: [PATCH 04/14] font: Fix several integer overflows in
+ grub_font_construct_glyph()
+
+This patch fixes several integer overflows in grub_font_construct_glyph().
+Glyphs of invalid size, zero or leading to an overflow, are rejected.
+The inconsistency between "glyph" and "max_glyph_size" when grub_malloc()
+returns NULL is fixed too.
+
+Fixes: CVE-2022-2601
+
+Reported-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/font/font.c | 29 +++++++++++++++++------------
+ 1 file changed, 17 insertions(+), 12 deletions(-)
+
+diff --git a/grub-core/font/font.c b/grub-core/font/font.c
+index e781521a7..e6548892f 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -1517,6 +1517,7 @@ grub_font_construct_glyph (grub_font_t hinted_font,
+   struct grub_video_signed_rect bounds;
+   static struct grub_font_glyph *glyph = 0;
+   static grub_size_t max_glyph_size = 0;
++  grub_size_t cur_glyph_size;
+ 
+   ensure_comb_space (glyph_id);
+ 
+@@ -1533,29 +1534,33 @@ grub_font_construct_glyph (grub_font_t hinted_font,
+   if (!glyph_id->ncomb && !glyph_id->attributes)
+     return main_glyph;
+ 
+-  if (max_glyph_size < sizeof (*glyph) + (bounds.width * bounds.height + GRUB_CHAR_BIT - 1) / GRUB_CHAR_BIT)
++  if (grub_video_bitmap_calc_1bpp_bufsz (bounds.width, bounds.height, &cur_glyph_size) ||
++      grub_add (sizeof (*glyph), cur_glyph_size, &cur_glyph_size))
++    return main_glyph;
++
++  if (max_glyph_size < cur_glyph_size)
+     {
+       grub_free (glyph);
+-      max_glyph_size = (sizeof (*glyph) + (bounds.width * bounds.height + GRUB_CHAR_BIT - 1) / GRUB_CHAR_BIT) * 2;
+-      if (max_glyph_size < 8)
+-	max_glyph_size = 8;
+-      glyph = grub_malloc (max_glyph_size);
++      if (grub_mul (cur_glyph_size, 2, &max_glyph_size))
++	max_glyph_size = 0;
++      glyph = max_glyph_size > 0 ? grub_malloc (max_glyph_size) : NULL;
+     }
+   if (!glyph)
+     {
++      max_glyph_size = 0;
+       grub_errno = GRUB_ERR_NONE;
+       return main_glyph;
+     }
+ 
+-  grub_memset (glyph, 0, sizeof (*glyph)
+-	       + (bounds.width * bounds.height
+-		  + GRUB_CHAR_BIT - 1) / GRUB_CHAR_BIT);
++  grub_memset (glyph, 0, cur_glyph_size);
+ 
+   glyph->font = main_glyph->font;
+-  glyph->width = bounds.width;
+-  glyph->height = bounds.height;
+-  glyph->offset_x = bounds.x;
+-  glyph->offset_y = bounds.y;
++  if (bounds.width == 0 || bounds.height == 0 ||
++      grub_cast (bounds.width, &glyph->width) ||
++      grub_cast (bounds.height, &glyph->height) ||
++      grub_cast (bounds.x, &glyph->offset_x) ||
++      grub_cast (bounds.y, &glyph->offset_y))
++    return main_glyph;
+ 
+   if (glyph_id->attributes & GRUB_UNICODE_GLYPH_ATTRIBUTE_MIRROR)
+     grub_font_blit_glyph_mirror (glyph, main_glyph,
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0005-font-Remove-grub_font_dup_glyph.patch b/debian/patches/cve_2022_2601/0005-font-Remove-grub_font_dup_glyph.patch
new file mode 100644
index 0000000..7c957a6
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0005-font-Remove-grub_font_dup_glyph.patch
@@ -0,0 +1,42 @@
+From 25ad31c19c331aaa2dbd9bd2b2e2655de5766a9d Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Fri, 5 Aug 2022 02:13:29 +0800
+Subject: [PATCH 05/14] font: Remove grub_font_dup_glyph()
+
+Remove grub_font_dup_glyph() since nobody is using it since 2013, and
+I'm too lazy to fix the integer overflow problem in it.
+
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/font/font.c | 14 --------------
+ 1 file changed, 14 deletions(-)
+
+diff --git a/grub-core/font/font.c b/grub-core/font/font.c
+index e6548892f..a8576ffec 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -1055,20 +1055,6 @@ grub_font_get_glyph_with_fallback (grub_font_t font, grub_uint32_t code)
+   return best_glyph;
+ }
+ 
+-#if 0
+-static struct grub_font_glyph *
+-grub_font_dup_glyph (struct grub_font_glyph *glyph)
+-{
+-  static struct grub_font_glyph *ret;
+-  ret = grub_malloc (sizeof (*ret) + (glyph->width * glyph->height + 7) / 8);
+-  if (!ret)
+-    return NULL;
+-  grub_memcpy (ret, glyph, sizeof (*ret)
+-	       + (glyph->width * glyph->height + 7) / 8);
+-  return ret;
+-}
+-#endif
+-
+ /* FIXME: suboptimal.  */
+ static void
+ grub_font_blit_glyph (struct grub_font_glyph *target,
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0006-font-Fix-integer-overflow-in-ensure_comb_space.patch b/debian/patches/cve_2022_2601/0006-font-Fix-integer-overflow-in-ensure_comb_space.patch
new file mode 100644
index 0000000..f35c646
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0006-font-Fix-integer-overflow-in-ensure_comb_space.patch
@@ -0,0 +1,48 @@
+From b2740b7e4a03bb8331d48b54b119afea76bb9d5f Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Fri, 5 Aug 2022 02:27:05 +0800
+Subject: [PATCH 06/14] font: Fix integer overflow in ensure_comb_space()
+
+In fact it can't overflow at all because glyph_id->ncomb is only 8-bit
+wide. But let's keep safe if somebody changes the width of glyph_id->ncomb
+in the future. This patch also fixes the inconsistency between
+render_max_comb_glyphs and render_combining_glyphs when grub_malloc()
+returns NULL.
+
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/font/font.c | 14 +++++++++-----
+ 1 file changed, 9 insertions(+), 5 deletions(-)
+
+diff --git a/grub-core/font/font.c b/grub-core/font/font.c
+index a8576ffec..9e3e0a94e 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -1468,14 +1468,18 @@ ensure_comb_space (const struct grub_unicode_glyph *glyph_id)
+   if (glyph_id->ncomb <= render_max_comb_glyphs)
+     return;
+ 
+-  render_max_comb_glyphs = 2 * glyph_id->ncomb;
+-  if (render_max_comb_glyphs < 8)
++  if (grub_mul (glyph_id->ncomb, 2, &render_max_comb_glyphs))
++    render_max_comb_glyphs = 0;
++  if (render_max_comb_glyphs > 0 && render_max_comb_glyphs < 8)
+     render_max_comb_glyphs = 8;
+   grub_free (render_combining_glyphs);
+-  render_combining_glyphs = grub_malloc (render_max_comb_glyphs
+-					 * sizeof (render_combining_glyphs[0]));
++  render_combining_glyphs = (render_max_comb_glyphs > 0) ?
++    grub_calloc (render_max_comb_glyphs, sizeof (render_combining_glyphs[0])) : NULL;
+   if (!render_combining_glyphs)
+-    grub_errno = 0;
++    {
++      render_max_comb_glyphs = 0;
++      grub_errno = GRUB_ERR_NONE;
++    }
+ }
+ 
+ int
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0007-font-Fix-integer-overflow-in-BMP-index.patch b/debian/patches/cve_2022_2601/0007-font-Fix-integer-overflow-in-BMP-index.patch
new file mode 100644
index 0000000..7d426f0
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0007-font-Fix-integer-overflow-in-BMP-index.patch
@@ -0,0 +1,65 @@
+From afda8b60ba0712abe01ae1e64c5f7a067a0e6492 Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Mon, 15 Aug 2022 02:04:58 +0800
+Subject: [PATCH 07/14] font: Fix integer overflow in BMP index
+
+The BMP index (font->bmp_idx) is designed as a reverse lookup table of
+char entries (font->char_index), in order to speed up lookups for BMP
+chars (i.e. code < 0x10000). The values in BMP index are the subscripts
+of the corresponding char entries, stored in grub_uint16_t, while 0xffff
+means not found.
+
+This patch fixes the problem of large subscript truncated to grub_uint16_t,
+leading BMP index to return wrong char entry or report false miss. The
+code now checks for bounds and uses BMP index as a hint, and fallbacks
+to binary-search if necessary.
+
+On the occasion add a comment about BMP index is initialized to 0xffff.
+
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/font/font.c | 13 +++++++++----
+ 1 file changed, 9 insertions(+), 4 deletions(-)
+
+diff --git a/grub-core/font/font.c b/grub-core/font/font.c
+index 9e3e0a94e..e4cb0d867 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -300,6 +300,8 @@ load_font_index (grub_file_t file, grub_uint32_t sect_length, struct
+   font->bmp_idx = grub_malloc (0x10000 * sizeof (grub_uint16_t));
+   if (!font->bmp_idx)
+     return 1;
++
++  /* Init the BMP index array to 0xffff. */
+   grub_memset (font->bmp_idx, 0xff, 0x10000 * sizeof (grub_uint16_t));
+ 
+ 
+@@ -328,7 +330,7 @@ load_font_index (grub_file_t file, grub_uint32_t sect_length, struct
+ 	  return 1;
+ 	}
+ 
+-      if (entry->code < 0x10000)
++      if (entry->code < 0x10000 && i < 0xffff)
+ 	font->bmp_idx[entry->code] = i;
+ 
+       last_code = entry->code;
+@@ -696,9 +698,12 @@ find_glyph (const grub_font_t font, grub_uint32_t code)
+   /* Use BMP index if possible.  */
+   if (code < 0x10000 && font->bmp_idx)
+     {
+-      if (font->bmp_idx[code] == 0xffff)
+-	return 0;
+-      return &table[font->bmp_idx[code]];
++      if (font->bmp_idx[code] < 0xffff)
++	return &table[font->bmp_idx[code]];
++      /*
++       * When we are here then lookup in BMP index result in miss,
++       * fallthough to binary-search.
++       */
+     }
+ 
+   /* Do a binary search in `char_index', which is ordered by code point.  */
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0008-font-Fix-integer-underflow-in-binary-search-of-char-.patch b/debian/patches/cve_2022_2601/0008-font-Fix-integer-underflow-in-binary-search-of-char-.patch
new file mode 100644
index 0000000..0db8d15
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0008-font-Fix-integer-underflow-in-binary-search-of-char-.patch
@@ -0,0 +1,86 @@
+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
+
diff --git a/debian/patches/cve_2022_2601/0009-kern-efi-sb-Enforce-verification-of-font-files.patch b/debian/patches/cve_2022_2601/0009-kern-efi-sb-Enforce-verification-of-font-files.patch
new file mode 100644
index 0000000..705835a
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0009-kern-efi-sb-Enforce-verification-of-font-files.patch
@@ -0,0 +1,54 @@
+From 630deb8c0d8b02b670ced4b7030414bcf17aa080 Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Sun, 14 Aug 2022 15:51:54 +0800
+Subject: [PATCH 09/14] kern/efi/sb: Enforce verification of font files
+
+As a mitigation and hardening measure enforce verification of font
+files. Then only trusted font files can be load. This will reduce the
+attack surface at cost of losing the ability of end-users to customize
+fonts if e.g. UEFI Secure Boot is enabled. Vendors can always customize
+fonts because they have ability to pack fonts into their GRUB bundles.
+
+This goal is achieved by:
+
+  * Removing GRUB_FILE_TYPE_FONT from shim lock verifier's
+    skip-verification list.
+
+  * Adding GRUB_FILE_TYPE_FONT to lockdown verifier's defer-auth list,
+    so font files must be verified by a verifier before they can be loaded.
+
+Suggested-by: Daniel Kiper <daniel.kiper@oracle.com>
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/kern/efi/sb.c   | 1 -
+ grub-core/kern/lockdown.c | 1 +
+ 2 files changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/grub-core/kern/efi/sb.c b/grub-core/kern/efi/sb.c
+index 89c4bb3fd..db42c2539 100644
+--- a/grub-core/kern/efi/sb.c
++++ b/grub-core/kern/efi/sb.c
+@@ -145,7 +145,6 @@ shim_lock_verifier_init (grub_file_t io __attribute__ ((unused)),
+     case GRUB_FILE_TYPE_PRINT_BLOCKLIST:
+     case GRUB_FILE_TYPE_TESTLOAD:
+     case GRUB_FILE_TYPE_GET_SIZE:
+-    case GRUB_FILE_TYPE_FONT:
+     case GRUB_FILE_TYPE_ZFS_ENCRYPTION_KEY:
+     case GRUB_FILE_TYPE_CAT:
+     case GRUB_FILE_TYPE_HEXCAT:
+diff --git a/grub-core/kern/lockdown.c b/grub-core/kern/lockdown.c
+index 0bc70fd42..af6d493cd 100644
+--- a/grub-core/kern/lockdown.c
++++ b/grub-core/kern/lockdown.c
+@@ -51,6 +51,7 @@ lockdown_verifier_init (grub_file_t io __attribute__ ((unused)),
+     case GRUB_FILE_TYPE_EFI_CHAINLOADED_IMAGE:
+     case GRUB_FILE_TYPE_ACPI_TABLE:
+     case GRUB_FILE_TYPE_DEVICE_TREE_IMAGE:
++    case GRUB_FILE_TYPE_FONT:
+       *flags = GRUB_VERIFY_FLAGS_DEFER_AUTH;
+ 
+       /* Fall through. */
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0010-fbutil-Fix-integer-overflow.patch b/debian/patches/cve_2022_2601/0010-fbutil-Fix-integer-overflow.patch
new file mode 100644
index 0000000..8dcac96
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0010-fbutil-Fix-integer-overflow.patch
@@ -0,0 +1,85 @@
+From 50a11a81bc842c58962244a2dc86bbd31a426e12 Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Tue, 6 Sep 2022 03:03:21 +0800
+Subject: [PATCH 10/14] fbutil: Fix integer overflow
+
+Expressions like u64 = u32 * u32 are unsafe because their products are
+truncated to u32 even if left hand side is u64. This patch fixes all
+problems like that one in fbutil.
+
+To get right result not only left hand side have to be u64 but it's also
+necessary to cast at least one of the operands of all leaf operators of
+right hand side to u64, e.g. u64 = u32 * u32 + u32 * u32 should be
+u64 = (u64)u32 * u32 + (u64)u32 * u32.
+
+For 1-bit bitmaps grub_uint64_t have to be used. It's safe because any
+combination of values in (grub_uint64_t)u32 * u32 + u32 expression will
+not overflow grub_uint64_t.
+
+Other expressions like ptr + u32 * u32 + u32 * u32 are also vulnerable.
+They should be ptr + (grub_addr_t)u32 * u32 + (grub_addr_t)u32 * u32.
+
+This patch also adds a comment to grub_video_fb_get_video_ptr() which
+says it's arguments must be valid and no sanity check is performed
+(like its siblings in grub-core/video/fb/fbutil.c).
+
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/video/fb/fbutil.c |  4 ++--
+ include/grub/fbutil.h       | 13 +++++++++----
+ 2 files changed, 11 insertions(+), 6 deletions(-)
+
+diff --git a/grub-core/video/fb/fbutil.c b/grub-core/video/fb/fbutil.c
+index b98bb51fe..25ef39f47 100644
+--- a/grub-core/video/fb/fbutil.c
++++ b/grub-core/video/fb/fbutil.c
+@@ -67,7 +67,7 @@ get_pixel (struct grub_video_fbblit_info *source,
+     case 1:
+       if (source->mode_info->blit_format == GRUB_VIDEO_BLIT_FORMAT_1BIT_PACKED)
+         {
+-          int bit_index = y * source->mode_info->width + x;
++          grub_uint64_t bit_index = (grub_uint64_t) y * source->mode_info->width + x;
+           grub_uint8_t *ptr = source->data + bit_index / 8;
+           int bit_pos = 7 - bit_index % 8;
+           color = (*ptr >> bit_pos) & 0x01;
+@@ -138,7 +138,7 @@ set_pixel (struct grub_video_fbblit_info *source,
+     case 1:
+       if (source->mode_info->blit_format == GRUB_VIDEO_BLIT_FORMAT_1BIT_PACKED)
+         {
+-          int bit_index = y * source->mode_info->width + x;
++          grub_uint64_t bit_index = (grub_uint64_t) y * source->mode_info->width + x;
+           grub_uint8_t *ptr = source->data + bit_index / 8;
+           int bit_pos = 7 - bit_index % 8;
+           *ptr = (*ptr & ~(1 << bit_pos)) | ((color & 0x01) << bit_pos);
+diff --git a/include/grub/fbutil.h b/include/grub/fbutil.h
+index 4205eb917..78a1ab3b4 100644
+--- a/include/grub/fbutil.h
++++ b/include/grub/fbutil.h
+@@ -31,14 +31,19 @@ struct grub_video_fbblit_info
+   grub_uint8_t *data;
+ };
+ 
+-/* Don't use for 1-bit bitmaps, addressing needs to be done at the bit level
+-   and it doesn't make sense, in general, to ask for a pointer
+-   to a particular pixel's data.  */
++/*
++ * Don't use for 1-bit bitmaps, addressing needs to be done at the bit level
++ * and it doesn't make sense, in general, to ask for a pointer
++ * to a particular pixel's data.
++ *
++ * This function assumes that bounds checking has been done in previous phase
++ * and they are opted out in here.
++ */
+ static inline void *
+ grub_video_fb_get_video_ptr (struct grub_video_fbblit_info *source,
+               unsigned int x, unsigned int y)
+ {
+-  return source->data + y * source->mode_info->pitch + x * source->mode_info->bytes_per_pixel;
++  return source->data + (grub_addr_t) y * source->mode_info->pitch + (grub_addr_t) x * source->mode_info->bytes_per_pixel;
+ }
+ 
+ /* Advance pointer by VAL bytes. If there is no unaligned access available,
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0011-font-Fix-an-integer-underflow-in-blit_comb.patch b/debian/patches/cve_2022_2601/0011-font-Fix-an-integer-underflow-in-blit_comb.patch
new file mode 100644
index 0000000..3a2b02c
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0011-font-Fix-an-integer-underflow-in-blit_comb.patch
@@ -0,0 +1,91 @@
+From 6d2668dea3774ed74c4cd1eadd146f1b846bc3d4 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 11/14] 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>
+---
+ 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 abd412a5e..3d3d803e8 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -1203,12 +1203,12 @@ 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);
+@@ -1221,7 +1221,7 @@ 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)
+@@ -1231,8 +1231,8 @@ 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;
+@@ -1305,7 +1305,7 @@ 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;
+@@ -1313,7 +1313,7 @@ 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;
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0012-font-Harden-grub_font_blit_glyph-and-grub_font_blit_.patch b/debian/patches/cve_2022_2601/0012-font-Harden-grub_font_blit_glyph-and-grub_font_blit_.patch
new file mode 100644
index 0000000..6296bf5
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0012-font-Harden-grub_font_blit_glyph-and-grub_font_blit_.patch
@@ -0,0 +1,75 @@
+From fcd7aa0c278f7cf3fb9f93f1a3966e1792339eb6 Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Mon, 24 Oct 2022 07:15:41 +0800
+Subject: [PATCH 12/14] font: Harden grub_font_blit_glyph() and
+ grub_font_blit_glyph_mirror()
+
+As a mitigation and hardening measure add sanity checks to
+grub_font_blit_glyph() and grub_font_blit_glyph_mirror(). This patch
+makes these two functions do nothing if target blitting area isn't fully
+contained in target bitmap. Therefore, if complex calculations in caller
+overflows and malicious coordinates are given, we are still safe because
+any coordinates which result in out-of-bound-write are rejected. However,
+this patch only checks for invalid coordinates, and doesn't provide any
+protection against invalid source glyph or destination glyph, e.g.
+mismatch between glyph size and buffer size.
+
+This hardening measure is designed to mitigate possible overflows in
+blit_comb(). If overflow occurs, it may return invalid bounding box
+during dry run and call grub_font_blit_glyph() with malicious
+coordinates during actual blitting. However, we are still safe because
+the scratch glyph itself is valid, although its size makes no sense, and
+any invalid coordinates are rejected.
+
+It would be better to call grub_fatal() if illegal parameter is detected.
+However, doing this may end up in a dangerous recursion because grub_fatal()
+would print messages to the screen and we are in the progress of drawing
+characters on the screen.
+
+Reported-by: Daniel Axtens <dja@axtens.net>
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/font/font.c | 14 ++++++++++++++
+ 1 file changed, 14 insertions(+)
+
+diff --git a/grub-core/font/font.c b/grub-core/font/font.c
+index 3d3d803e8..cf15dc2f9 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -1069,8 +1069,15 @@ static void
+ grub_font_blit_glyph (struct grub_font_glyph *target,
+ 		      struct grub_font_glyph *src, unsigned dx, unsigned dy)
+ {
++  grub_uint16_t max_x, max_y;
+   unsigned src_bit, tgt_bit, src_byte, tgt_byte;
+   unsigned i, j;
++
++  /* Harden against out-of-bound writes. */
++  if ((grub_add (dx, src->width, &max_x) || max_x > target->width) ||
++      (grub_add (dy, src->height, &max_y) || max_y > target->height))
++    return;
++
+   for (i = 0; i < src->height; i++)
+     {
+       src_bit = (src->width * i) % 8;
+@@ -1102,9 +1109,16 @@ grub_font_blit_glyph_mirror (struct grub_font_glyph *target,
+ 			     struct grub_font_glyph *src,
+ 			     unsigned dx, unsigned dy)
+ {
++  grub_uint16_t max_x, max_y;
+   unsigned tgt_bit, src_byte, tgt_byte;
+   signed src_bit;
+   unsigned i, j;
++
++  /* Harden against out-of-bound writes. */
++  if ((grub_add (dx, src->width, &max_x) || max_x > target->width) ||
++      (grub_add (dy, src->height, &max_y) || max_y > target->height))
++    return;
++
+   for (i = 0; i < src->height; i++)
+     {
+       src_bit = (src->width * i + src->width - 1) % 8;
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0013-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch b/debian/patches/cve_2022_2601/0013-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch
new file mode 100644
index 0000000..2db665f
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0013-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch
@@ -0,0 +1,36 @@
+From dd539d695482069d28b40f2d3821f710cdcf6ee6 Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Fri, 28 Oct 2022 17:29:16 +0800
+Subject: [PATCH 13/14] font: Assign null_font to glyphs in ascii_font_glyph[]
+
+The calculations in blit_comb() need information from glyph's font, e.g.
+grub_font_get_xheight(main_glyph->font). However, main_glyph->font is
+NULL if main_glyph comes from ascii_font_glyph[]. Therefore
+grub_font_get_*() crashes because of NULL pointer.
+
+There is already a solution, the null_font. So, assign it to those glyphs
+in ascii_font_glyph[].
+
+Reported-by: Daniel Axtens <dja@axtens.net>
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/font/font.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/grub-core/font/font.c b/grub-core/font/font.c
+index cf15dc2f9..3821937e6 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -137,7 +137,7 @@ ascii_glyph_lookup (grub_uint32_t code)
+ 	  ascii_font_glyph[current]->offset_x = 0;
+ 	  ascii_font_glyph[current]->offset_y = -2;
+ 	  ascii_font_glyph[current]->device_width = 8;
+-	  ascii_font_glyph[current]->font = NULL;
++	  ascii_font_glyph[current]->font = &null_font;
+ 
+ 	  grub_memcpy (ascii_font_glyph[current]->bitmap,
+ 		       &ascii_bitmaps[current * ASCII_BITMAP_SIZE],
+-- 
+2.30.2
+
diff --git a/debian/patches/cve_2022_2601/0014-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch b/debian/patches/cve_2022_2601/0014-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch
new file mode 100644
index 0000000..a94450a
--- /dev/null
+++ b/debian/patches/cve_2022_2601/0014-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch
@@ -0,0 +1,55 @@
+From da90d62316a3b105d2fbd7334d6521936bd6dcf6 Mon Sep 17 00:00:00 2001
+From: Zhang Boyang <zhangboyang.id@gmail.com>
+Date: Fri, 28 Oct 2022 21:31:39 +0800
+Subject: [PATCH 14/14] normal/charset: Fix an integer overflow in
+ grub_unicode_aglomerate_comb()
+
+The out->ncomb is a bit-field of 8 bits. So, the max possible value is 255.
+However, code in grub_unicode_aglomerate_comb() doesn't check for an
+overflow when incrementing out->ncomb. If out->ncomb is already 255,
+after incrementing it will get 0 instead of 256, and cause illegal
+memory access in subsequent processing.
+
+This patch introduces GRUB_UNICODE_NCOMB_MAX to represent the max
+acceptable value of ncomb. The code now checks for this limit and
+ignores additional combining characters when limit is reached.
+
+Reported-by: Daniel Axtens <dja@axtens.net>
+Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+---
+ grub-core/normal/charset.c | 3 +++
+ include/grub/unicode.h     | 2 ++
+ 2 files changed, 5 insertions(+)
+
+diff --git a/grub-core/normal/charset.c b/grub-core/normal/charset.c
+index 000e687bd..4f6647116 100644
+--- a/grub-core/normal/charset.c
++++ b/grub-core/normal/charset.c
+@@ -472,6 +472,9 @@ grub_unicode_aglomerate_comb (const grub_uint32_t *in, grub_size_t inlen,
+ 	  if (!haveout)
+ 	    continue;
+ 
++	  if (out->ncomb == GRUB_UNICODE_NCOMB_MAX)
++	    continue;
++
+ 	  if (comb_type == GRUB_UNICODE_COMB_MC
+ 	      || comb_type == GRUB_UNICODE_COMB_ME
+ 	      || comb_type == GRUB_UNICODE_COMB_MN)
+diff --git a/include/grub/unicode.h b/include/grub/unicode.h
+index 71a4d1a54..9360b0b97 100644
+--- a/include/grub/unicode.h
++++ b/include/grub/unicode.h
+@@ -147,7 +147,9 @@ struct grub_unicode_glyph
+   grub_uint8_t bidi_level:6; /* minimum: 6 */
+   enum grub_bidi_type bidi_type:5; /* minimum: :5 */
+ 
++#define GRUB_UNICODE_NCOMB_MAX ((1 << 8) - 1)
+   unsigned ncomb:8;
++
+   /* Hint by unicode subsystem how wide this character usually is.
+      Real width is determined by font. Set only in UTF-8 stream.  */
+   int estimated_width:8;
+-- 
+2.30.2
+