blob: 7d02ab94740e53826938f1b25d51d05cba80d7b8 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
From 042421e9e3d266ad0bb7805132041ef51ad3234d Mon Sep 17 00:00:00 2001
From: Adrian Johnson <ajohnson@redneon.com>
Date: Wed, 16 Aug 2017 22:52:35 -0400
Subject: [PATCH] cairo: Fix CVE-2017-9814
The bug happens because in some scenarios the variable size can
have a value of 0 at line 1288. And malloc(0) is not returning
NULL as some people could expect:
https://stackoverflow.com/questions/1073157/zero-size-malloc
malloc(0) returns the smallest chunk possible. So the line 1290
with the return is not execute. And the execution continues with
an invalid map.
Since the size is 0 the variable map is not initialized correctly
at load_trutype_table. So, later when the variable map is accessed
previous values from a freed chunk are used. This could allows an
attacker to control the variable map.
This patch have not merge in upstream now.
Upstream-Status: Backport [https://bugs.freedesktop.org/show_bug.cgi?id=101547]
CVE: CVE-2017-9814
Signed-off-by: Dengke Du <dengke.du@windriver.com>
---
src/cairo-truetype-subset.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/cairo-truetype-subset.c b/src/cairo-truetype-subset.c
index e3449a0..f77d11c 100644
--- a/src/cairo-truetype-subset.c
+++ b/src/cairo-truetype-subset.c
@@ -1285,7 +1285,7 @@ _cairo_truetype_reverse_cmap (cairo_scaled_font_t *scaled_font,
return CAIRO_INT_STATUS_UNSUPPORTED;
size = be16_to_cpu (map->length);
- map = malloc (size);
+ map = _cairo_malloc (size);
if (unlikely (map == NULL))
return _cairo_error (CAIRO_STATUS_NO_MEMORY);
--
2.8.1
|
