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-rw-r--r--meta/recipes-bsp/grub/files/CVE-2022-3775.patch95
1 files changed, 95 insertions, 0 deletions
diff --git a/meta/recipes-bsp/grub/files/CVE-2022-3775.patch b/meta/recipes-bsp/grub/files/CVE-2022-3775.patch
new file mode 100644
index 0000000000..853efd0486
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/CVE-2022-3775.patch
@@ -0,0 +1,95 @@
+From fdbe7209152ad6f09a1166f64f162017f2145ba3 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] 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>
+
+Upstream-Status: Backport from
+[https://git.savannah.gnu.org/cgit/grub.git/commit/?id=992c06191babc1e109caf40d6a07ec6fdef427af]
+CVE: CVE-2022-3775
+
+Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.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 0ff5525..7b1cbde 100644
+--- a/grub-core/font/font.c
++++ b/grub-core/font/font.c
+@@ -1206,12 +1206,12 @@ 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);
+@@ -1224,7 +1224,7 @@ 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)
+@@ -1234,8 +1234,8 @@ 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;
+@@ -1308,7 +1308,7 @@ 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;
+@@ -1316,7 +1316,7 @@ 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;