nalika / rpms / grub2

Forked from rpms/grub2 2 years ago
Clone

Blame SOURCES/0566-font-Fix-integer-overflow-in-ensure_comb_space.patch

a9bbe0
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
a9bbe0
From: Zhang Boyang <zhangboyang.id@gmail.com>
a9bbe0
Date: Fri, 5 Aug 2022 02:27:05 +0800
a9bbe0
Subject: [PATCH] font: Fix integer overflow in ensure_comb_space()
a9bbe0
a9bbe0
In fact it can't overflow at all because glyph_id->ncomb is only 8-bit
a9bbe0
wide. But let's keep safe if somebody changes the width of glyph_id->ncomb
a9bbe0
in the future. This patch also fixes the inconsistency between
a9bbe0
render_max_comb_glyphs and render_combining_glyphs when grub_malloc()
a9bbe0
returns NULL.
a9bbe0
a9bbe0
Signed-off-by: Zhang Boyang <zhangboyang.id@gmail.com>
a9bbe0
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
a9bbe0
(cherry picked from commit b2740b7e4a03bb8331d48b54b119afea76bb9d5f)
a9bbe0
(cherry picked from commit f66ea1e60c347408e92b6695d5105c7e0f24d568)
a9bbe0
(cherry picked from commit 0e07159c24cdbb62a9d19fba8199065b049e03c7)
a9bbe0
---
a9bbe0
 grub-core/font/font.c | 14 +++++++++-----
a9bbe0
 1 file changed, 9 insertions(+), 5 deletions(-)
a9bbe0
a9bbe0
diff --git a/grub-core/font/font.c b/grub-core/font/font.c
a9bbe0
index 347e9dfa29..1367e44743 100644
a9bbe0
--- a/grub-core/font/font.c
a9bbe0
+++ b/grub-core/font/font.c
a9bbe0
@@ -1468,14 +1468,18 @@ ensure_comb_space (const struct grub_unicode_glyph *glyph_id)
a9bbe0
   if (glyph_id->ncomb <= render_max_comb_glyphs)
a9bbe0
     return;
a9bbe0
 
a9bbe0
-  render_max_comb_glyphs = 2 * glyph_id->ncomb;
a9bbe0
-  if (render_max_comb_glyphs < 8)
a9bbe0
+  if (grub_mul (glyph_id->ncomb, 2, &render_max_comb_glyphs))
a9bbe0
+    render_max_comb_glyphs = 0;
a9bbe0
+  if (render_max_comb_glyphs > 0 && render_max_comb_glyphs < 8)
a9bbe0
     render_max_comb_glyphs = 8;
a9bbe0
   grub_free (render_combining_glyphs);
a9bbe0
-  render_combining_glyphs = grub_malloc (render_max_comb_glyphs
a9bbe0
-					 * sizeof (render_combining_glyphs[0]));
a9bbe0
+  render_combining_glyphs = (render_max_comb_glyphs > 0) ?
a9bbe0
+    grub_calloc (render_max_comb_glyphs, sizeof (render_combining_glyphs[0])) : NULL;
a9bbe0
   if (!render_combining_glyphs)
a9bbe0
-    grub_errno = 0;
a9bbe0
+    {
a9bbe0
+      render_max_comb_glyphs = 0;
a9bbe0
+      grub_errno = GRUB_ERR_NONE;
a9bbe0
+    }
a9bbe0
 }
a9bbe0
 
a9bbe0
 int