80 lines
2.9 KiB
Diff
80 lines
2.9 KiB
Diff
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Zhang Boyang <zhangboyang.id@gmail.com>
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Date: Fri, 5 Aug 2022 01:58:27 +0800
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Subject: [PATCH] font: Fix several integer overflows in
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grub_font_construct_glyph()
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This patch fixes several integer overflows in grub_font_construct_glyph().
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Glyphs of invalid size, zero or leading to an overflow, are rejected.
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The inconsistency between "glyph" and "max_glyph_size" when grub_malloc()
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returns NULL is fixed too.
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Fixes: CVE-2022-2601
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Reported-by: Zhang Boyang <zhangboyang.id@gmail.com>
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Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
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Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
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(cherry picked from commit b1805f251b31a9d3cfae5c3572ddfa630145dbbf)
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---
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grub-core/font/font.c | 29 +++++++++++++++++------------
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1 file changed, 17 insertions(+), 12 deletions(-)
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diff --git a/grub-core/font/font.c b/grub-core/font/font.c
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index 6a3fbebbd8..1fa181d4ca 100644
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--- a/grub-core/font/font.c
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+++ b/grub-core/font/font.c
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@@ -1517,6 +1517,7 @@ grub_font_construct_glyph (grub_font_t hinted_font,
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struct grub_video_signed_rect bounds;
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static struct grub_font_glyph *glyph = 0;
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static grub_size_t max_glyph_size = 0;
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+ grub_size_t cur_glyph_size;
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ensure_comb_space (glyph_id);
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@@ -1533,29 +1534,33 @@ grub_font_construct_glyph (grub_font_t hinted_font,
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if (!glyph_id->ncomb && !glyph_id->attributes)
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return main_glyph;
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- if (max_glyph_size < sizeof (*glyph) + (bounds.width * bounds.height + GRUB_CHAR_BIT - 1) / GRUB_CHAR_BIT)
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+ if (grub_video_bitmap_calc_1bpp_bufsz (bounds.width, bounds.height, &cur_glyph_size) ||
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+ grub_add (sizeof (*glyph), cur_glyph_size, &cur_glyph_size))
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+ return main_glyph;
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+
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+ if (max_glyph_size < cur_glyph_size)
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{
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grub_free (glyph);
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- max_glyph_size = (sizeof (*glyph) + (bounds.width * bounds.height + GRUB_CHAR_BIT - 1) / GRUB_CHAR_BIT) * 2;
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- if (max_glyph_size < 8)
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- max_glyph_size = 8;
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- glyph = grub_malloc (max_glyph_size);
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+ if (grub_mul (cur_glyph_size, 2, &max_glyph_size))
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+ max_glyph_size = 0;
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+ glyph = max_glyph_size > 0 ? grub_malloc (max_glyph_size) : NULL;
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}
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if (!glyph)
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{
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+ max_glyph_size = 0;
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grub_errno = GRUB_ERR_NONE;
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return main_glyph;
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}
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- grub_memset (glyph, 0, sizeof (*glyph)
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- + (bounds.width * bounds.height
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- + GRUB_CHAR_BIT - 1) / GRUB_CHAR_BIT);
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+ grub_memset (glyph, 0, cur_glyph_size);
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glyph->font = main_glyph->font;
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- glyph->width = bounds.width;
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- glyph->height = bounds.height;
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- glyph->offset_x = bounds.x;
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- glyph->offset_y = bounds.y;
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+ if (bounds.width == 0 || bounds.height == 0 ||
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+ grub_cast (bounds.width, &glyph->width) ||
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+ grub_cast (bounds.height, &glyph->height) ||
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+ grub_cast (bounds.x, &glyph->offset_x) ||
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+ grub_cast (bounds.y, &glyph->offset_y))
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+ return main_glyph;
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if (glyph_id->attributes & GRUB_UNICODE_GLYPH_ATTRIBUTE_MIRROR)
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grub_font_blit_glyph_mirror (glyph, main_glyph,
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