1 files changed, 117 insertions, 0 deletions

diff --git a/meta/recipes-bsp/grub/files/font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch b/meta/recipes-bsp/grub/files/font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch
new file mode 100644
index 0000000000..d4ba3cafc5
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch
@@ -0,0 +1,117 @@
+From 1f511ae054fe42dce7aedfbfe0f234fa1e0a7a3e 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-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=9c76ec09ae08155df27cd237eaea150b4f02f532]
+
+Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
+Signed-off-by: Hitendra Prajapati <hprajapati@mvista.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 5edb477..df17dba 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -733,7 +733,8 @@ 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.  */
+@@ -760,9 +761,17 @@ 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 5728f8c..0d9603f 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 c17b89b..bb0f826 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
+-- 
+2.25.1
+