diff --git a/0286-font-Reject-glyphs-exceeds-font-max_glyph_width-or-f.patch b/0286-font-Reject-glyphs-exceeds-font-max_glyph_width-or-f.patch new file mode 100644 index 0000000..e0dd347 --- /dev/null +++ b/0286-font-Reject-glyphs-exceeds-font-max_glyph_width-or-f.patch @@ -0,0 +1,31 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Wed, 3 Aug 2022 19:45:33 +0800 +Subject: [PATCH] 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 +Reviewed-by: Daniel Kiper +(cherry picked from commit 5760fcfd466cc757540ea0d591bad6a08caeaa16) +--- + 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 d09bb38d89..2f09a4a55b 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; diff --git a/0287-font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch b/0287-font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch new file mode 100644 index 0000000..b5f10f6 --- /dev/null +++ b/0287-font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch @@ -0,0 +1,110 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +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 +Reviewed-by: Daniel Kiper +(cherry picked from commit 941d10ad6f1dcbd12fb613002249e29ba035f985) +--- + 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 2f09a4a55b..6a3fbebbd8 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 5728f8ca3a..0d9603f619 100644 +--- a/include/grub/bitmap.h ++++ b/include/grub/bitmap.h +@@ -23,6 +23,7 @@ + #include + #include + #include ++#include + + 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 c17b89bba1..bb0f826de1 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/0288-font-Fix-several-integer-overflows-in-grub_font_cons.patch b/0288-font-Fix-several-integer-overflows-in-grub_font_cons.patch new file mode 100644 index 0000000..3c76eb4 --- /dev/null +++ b/0288-font-Fix-several-integer-overflows-in-grub_font_cons.patch @@ -0,0 +1,79 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Fri, 5 Aug 2022 01:58:27 +0800 +Subject: [PATCH] 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 +Signed-off-by: Zhang Boyang +Reviewed-by: Daniel Kiper +(cherry picked from commit b1805f251b31a9d3cfae5c3572ddfa630145dbbf) +--- + 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 6a3fbebbd8..1fa181d4ca 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, diff --git a/0289-font-Remove-grub_font_dup_glyph.patch b/0289-font-Remove-grub_font_dup_glyph.patch new file mode 100644 index 0000000..4c3db92 --- /dev/null +++ b/0289-font-Remove-grub_font_dup_glyph.patch @@ -0,0 +1,40 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Fri, 5 Aug 2022 02:13:29 +0800 +Subject: [PATCH] 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 +Reviewed-by: Daniel Kiper +(cherry picked from commit 25ad31c19c331aaa2dbd9bd2b2e2655de5766a9d) +--- + 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 1fa181d4ca..a115a63b0c 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, diff --git a/0290-font-Fix-integer-overflow-in-ensure_comb_space.patch b/0290-font-Fix-integer-overflow-in-ensure_comb_space.patch new file mode 100644 index 0000000..6b73038 --- /dev/null +++ b/0290-font-Fix-integer-overflow-in-ensure_comb_space.patch @@ -0,0 +1,46 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Fri, 5 Aug 2022 02:27:05 +0800 +Subject: [PATCH] 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 +Reviewed-by: Daniel Kiper +(cherry picked from commit b2740b7e4a03bb8331d48b54b119afea76bb9d5f) +--- + 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 a115a63b0c..d0e6340404 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 diff --git a/0291-font-Fix-integer-overflow-in-BMP-index.patch b/0291-font-Fix-integer-overflow-in-BMP-index.patch new file mode 100644 index 0000000..5e10699 --- /dev/null +++ b/0291-font-Fix-integer-overflow-in-BMP-index.patch @@ -0,0 +1,63 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Mon, 15 Aug 2022 02:04:58 +0800 +Subject: [PATCH] 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 +Reviewed-by: Daniel Kiper +(cherry picked from commit afda8b60ba0712abe01ae1e64c5f7a067a0e6492) +--- + 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 d0e6340404..b208a28717 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. */ diff --git a/0292-font-Fix-integer-underflow-in-binary-search-of-char-.patch b/0292-font-Fix-integer-underflow-in-binary-search-of-char-.patch new file mode 100644 index 0000000..e81824b --- /dev/null +++ b/0292-font-Fix-integer-underflow-in-binary-search-of-char-.patch @@ -0,0 +1,83 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Sun, 14 Aug 2022 18:09:38 +0800 +Subject: [PATCH] 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 +Reviewed-by: Daniel Kiper +(cherry picked from commit c140a086838e7c9af87842036f891b8393a8c4bc) +--- + 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 b208a28717..193dfec045 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; ++ /* ++ * 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; + +- if (!table) +- return 0; +- +- 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 diff --git a/0293-kern-efi-sb-Enforce-verification-of-font-files.patch b/0293-kern-efi-sb-Enforce-verification-of-font-files.patch new file mode 100644 index 0000000..1a381b0 --- /dev/null +++ b/0293-kern-efi-sb-Enforce-verification-of-font-files.patch @@ -0,0 +1,52 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Sun, 14 Aug 2022 15:51:54 +0800 +Subject: [PATCH] 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 +Signed-off-by: Zhang Boyang +Reviewed-by: Daniel Kiper +(cherry picked from commit 630deb8c0d8b02b670ced4b7030414bcf17aa080) +--- + 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 89c4bb3fd1..db42c2539f 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 0bc70fd42d..af6d493cd3 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. */ diff --git a/0294-fbutil-Fix-integer-overflow.patch b/0294-fbutil-Fix-integer-overflow.patch new file mode 100644 index 0000000..4d32dbd --- /dev/null +++ b/0294-fbutil-Fix-integer-overflow.patch @@ -0,0 +1,83 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Tue, 6 Sep 2022 03:03:21 +0800 +Subject: [PATCH] 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 +Reviewed-by: Daniel Kiper +(cherry picked from commit 50a11a81bc842c58962244a2dc86bbd31a426e12) +--- + 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 b98bb51fe8..25ef39f47d 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 4205eb917f..78a1ab3b45 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, diff --git a/0295-font-Fix-an-integer-underflow-in-blit_comb.patch b/0295-font-Fix-an-integer-underflow-in-blit_comb.patch new file mode 100644 index 0000000..72f4308 --- /dev/null +++ b/0295-font-Fix-an-integer-underflow-in-blit_comb.patch @@ -0,0 +1,89 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +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 +Signed-off-by: Zhang Boyang +Reviewed-by: Daniel Kiper +(cherry picked from commit 6d2668dea3774ed74c4cd1eadd146f1b846bc3d4) +--- + 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 193dfec045..12a5f0d08c 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; diff --git a/0296-font-Harden-grub_font_blit_glyph-and-grub_font_blit_.patch b/0296-font-Harden-grub_font_blit_glyph-and-grub_font_blit_.patch new file mode 100644 index 0000000..5207c12 --- /dev/null +++ b/0296-font-Harden-grub_font_blit_glyph-and-grub_font_blit_.patch @@ -0,0 +1,73 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Mon, 24 Oct 2022 07:15:41 +0800 +Subject: [PATCH] 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 +Signed-off-by: Zhang Boyang +Reviewed-by: Daniel Kiper +(cherry picked from commit fcd7aa0c278f7cf3fb9f93f1a3966e1792339eb6) +--- + 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 12a5f0d08c..29fbb94294 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; diff --git a/0297-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch b/0297-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch new file mode 100644 index 0000000..c2bcc18 --- /dev/null +++ b/0297-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch @@ -0,0 +1,34 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Fri, 28 Oct 2022 17:29:16 +0800 +Subject: [PATCH] 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 +Signed-off-by: Zhang Boyang +Reviewed-by: Daniel Kiper +(cherry picked from commit dd539d695482069d28b40f2d3821f710cdcf6ee6) +--- + 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 29fbb94294..e6616e610c 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], diff --git a/0298-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch b/0298-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch new file mode 100644 index 0000000..ec2184f --- /dev/null +++ b/0298-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch @@ -0,0 +1,53 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: Zhang Boyang +Date: Fri, 28 Oct 2022 21:31:39 +0800 +Subject: [PATCH] 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 +Signed-off-by: Zhang Boyang +Reviewed-by: Daniel Kiper +(cherry picked from commit da90d62316a3b105d2fbd7334d6521936bd6dcf6) +--- + 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 7a5a7c153c..c243ca6dae 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 4de986a857..c4f6fca043 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; diff --git a/grub.patches b/grub.patches index a90e921..f0f1d83 100644 --- a/grub.patches +++ b/grub.patches @@ -283,3 +283,16 @@ Patch0282: 0282-x86-efi-Fix-an-incorrect-array-size-in-kernel-alloca.patch Patch0283: 0283-commands-efi-tpm-Refine-the-status-of-log-event.patch Patch0284: 0284-commands-efi-tpm-Use-grub_strcpy-instead-of-grub_mem.patch Patch0285: 0285-efi-tpm-Add-EFI_CC_MEASUREMENT_PROTOCOL-support.patch +Patch0286: 0286-font-Reject-glyphs-exceeds-font-max_glyph_width-or-f.patch +Patch0287: 0287-font-Fix-size-overflow-in-grub_font_get_glyph_intern.patch +Patch0288: 0288-font-Fix-several-integer-overflows-in-grub_font_cons.patch +Patch0289: 0289-font-Remove-grub_font_dup_glyph.patch +Patch0290: 0290-font-Fix-integer-overflow-in-ensure_comb_space.patch +Patch0291: 0291-font-Fix-integer-overflow-in-BMP-index.patch +Patch0292: 0292-font-Fix-integer-underflow-in-binary-search-of-char-.patch +Patch0293: 0293-kern-efi-sb-Enforce-verification-of-font-files.patch +Patch0294: 0294-fbutil-Fix-integer-overflow.patch +Patch0295: 0295-font-Fix-an-integer-underflow-in-blit_comb.patch +Patch0296: 0296-font-Harden-grub_font_blit_glyph-and-grub_font_blit_.patch +Patch0297: 0297-font-Assign-null_font-to-glyphs-in-ascii_font_glyph.patch +Patch0298: 0298-normal-charset-Fix-an-integer-overflow-in-grub_unico.patch diff --git a/grub2.spec b/grub2.spec index 0e504c2..9022dcb 100644 --- a/grub2.spec +++ b/grub2.spec @@ -17,7 +17,7 @@ Name: grub2 Epoch: 1 Version: 2.06 -Release: 62%{?dist} +Release: 63%{?dist} Summary: Bootloader with support for Linux, Multiboot and more License: GPLv3+ URL: http://www.gnu.org/software/grub/ @@ -529,6 +529,9 @@ mv ${EFI_HOME}/grub.cfg.stb ${EFI_HOME}/grub.cfg %endif %changelog +* Tue Nov 08 2022 Robbie Harwood - 1:2.06-63 +- Font fixes (CVE-2022-2601 batch) + * Tue Nov 01 2022 Robbie Harwood - 1:2.06-62 - Try dropping custom sort again - See-also: https://github.com/rpm-software-management/rpm/pull/2249 diff --git a/sbat.csv.in b/sbat.csv.in index 55b3d10..b338b5f 100755 --- a/sbat.csv.in +++ b/sbat.csv.in @@ -1,3 +1,3 @@ sbat,1,SBAT Version,sbat,1,https://github.com/rhboot/shim/blob/main/SBAT.md -grub,2,Free Software Foundation,grub,@@VERSION@@,https//www.gnu.org/software/grub/ +grub,3,Free Software Foundation,grub,@@VERSION@@,https//www.gnu.org/software/grub/ grub.rh,2,Red Hat,grub2,@@VERSION_RELEASE@@,mailto:secalert@redhat.com