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[SECURITY PATCH 05/13] font: Fix integer overflow in ensure_comb_space()
From: |
Daniel Kiper |
Subject: |
[SECURITY PATCH 05/13] font: Fix integer overflow in ensure_comb_space() |
Date: |
Tue, 15 Nov 2022 19:01:02 +0100 |
From: Zhang Boyang <zhangboyang.id@gmail.com>
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
--
2.11.0
- [SECURITY PATCH 00/13] Multiple GRUB2 vulnerabilities - 2022/11/15, Daniel Kiper, 2022/11/15
- [SECURITY PATCH 01/13] font: Reject glyphs exceeds font->max_glyph_width or font->max_glyph_height, Daniel Kiper, 2022/11/15
- [SECURITY PATCH 02/13] font: Fix size overflow in grub_font_get_glyph_internal(), Daniel Kiper, 2022/11/15
- [SECURITY PATCH 03/13] font: Fix several integer overflows in grub_font_construct_glyph(), Daniel Kiper, 2022/11/15
- [SECURITY PATCH 04/13] font: Remove grub_font_dup_glyph(), Daniel Kiper, 2022/11/15
- [SECURITY PATCH 10/13] font: Fix an integer underflow in blit_comb(), Daniel Kiper, 2022/11/15
- [SECURITY PATCH 05/13] font: Fix integer overflow in ensure_comb_space(),
Daniel Kiper <=
- [SECURITY PATCH 07/13] font: Fix integer underflow in binary search of char index, Daniel Kiper, 2022/11/15
- [SECURITY PATCH 08/13] kern/efi/sb: Enforce verification of font files, Daniel Kiper, 2022/11/15
- [SECURITY PATCH 09/13] fbutil: Fix integer overflow, Daniel Kiper, 2022/11/15
- [SECURITY PATCH 11/13] font: Harden grub_font_blit_glyph() and grub_font_blit_glyph_mirror(), Daniel Kiper, 2022/11/15
- [SECURITY PATCH 12/13] font: Assign null_font to glyphs in ascii_font_glyph[], Daniel Kiper, 2022/11/15
- [SECURITY PATCH 06/13] font: Fix integer overflow in BMP index, Daniel Kiper, 2022/11/15
- [SECURITY PATCH 13/13] normal/charset: Fix an integer overflow in grub_unicode_aglomerate_comb(), Daniel Kiper, 2022/11/15
- Re: [SECURITY PATCH 00/13] Multiple GRUB2 vulnerabilities - 2022/11/15, Daniel Kiper, 2022/11/15
- Re: [SECURITY PATCH 00/13] Multiple GRUB2 vulnerabilities - 2022/11/15, Daniel Kiper, 2022/11/16