summaryrefslogtreecommitdiff
path: root/gnu/packages/patches/glib-CVE-2021-27219-01.patch
blob: 5db360d468a99555795581c1f3b89995c296ab3d (about) (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
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
Backport of:

From 5e5f75a77e399c638be66d74e5daa8caeb433e00 Mon Sep 17 00:00:00 2001
From: Philip Withnall <pwithnall@endlessos.org>
Date: Thu, 4 Feb 2021 13:30:52 +0000
Subject: [PATCH 01/11] gstrfuncs: Add internal g_memdup2() function
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This will replace the existing `g_memdup()` function for use within
GLib. It has an unavoidable security flaw of taking its `byte_size`
argument as a `guint` rather than as a `gsize`. Most callers will
expect it to be a `gsize`, and may pass in large values which could
silently be truncated, resulting in an undersize allocation compared
to what the caller expects.

This could lead to a classic buffer overflow vulnerability for many
callers of `g_memdup()`.

`g_memdup2()`, in comparison, takes its `byte_size` as a `gsize`.

Spotted by Kevin Backhouse of GHSL.

In GLib 2.68, `g_memdup2()` will be a new public API. In this version
for backport to older stable releases, it’s a new `static inline` API
in a private header, so that use of `g_memdup()` within GLib can be
fixed without adding a new API in a stable release series.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
Helps: GHSL-2021-045
Helps: #2319
---
 docs/reference/glib/meson.build |  1 +
 glib/gstrfuncsprivate.h         | 55 +++++++++++++++++++++++++++++++++
 glib/meson.build                |  1 +
 glib/tests/strfuncs.c           | 23 ++++++++++++++
 4 files changed, 80 insertions(+)
 create mode 100644 glib/gstrfuncsprivate.h

diff --git a/docs/reference/glib/meson.build b/docs/reference/glib/meson.build
index bba7649f0..ee39f6d04 100644
--- a/docs/reference/glib/meson.build
+++ b/docs/reference/glib/meson.build
@@ -22,6 +22,7 @@ if get_option('gtk_doc')
     'gprintfint.h',
     'gmirroringtable.h',
     'gscripttable.h',
+    'gstrfuncsprivate.h',
     'glib-mirroring-tab',
     'gnulib',
     'pcre',
diff --git a/glib/gstrfuncsprivate.h b/glib/gstrfuncsprivate.h
new file mode 100644
index 000000000..85c88328a
--- /dev/null
+++ b/glib/gstrfuncsprivate.h
@@ -0,0 +1,55 @@
+/* GLIB - Library of useful routines for C programming
+ * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <glib.h>
+#include <string.h>
+
+/*
+ * g_memdup2:
+ * @mem: (nullable): the memory to copy.
+ * @byte_size: the number of bytes to copy.
+ *
+ * Allocates @byte_size bytes of memory, and copies @byte_size bytes into it
+ * from @mem. If @mem is %NULL it returns %NULL.
+ *
+ * This replaces g_memdup(), which was prone to integer overflows when
+ * converting the argument from a #gsize to a #guint.
+ *
+ * This static inline version is a backport of the new public API from
+ * GLib 2.68, kept internal to GLib for backport to older stable releases.
+ * See https://gitlab.gnome.org/GNOME/glib/-/issues/2319.
+ *
+ * Returns: (nullable): a pointer to the newly-allocated copy of the memory,
+ *    or %NULL if @mem is %NULL.
+ * Since: 2.68
+ */
+static inline gpointer
+g_memdup2 (gconstpointer mem,
+           gsize         byte_size)
+{
+  gpointer new_mem;
+
+  if (mem && byte_size != 0)
+    {
+      new_mem = g_malloc (byte_size);
+      memcpy (new_mem, mem, byte_size);
+    }
+  else
+    new_mem = NULL;
+
+  return new_mem;
+}
diff --git a/glib/meson.build b/glib/meson.build
index aaf5f00f5..5a6eea397 100644
--- a/glib/meson.build
+++ b/glib/meson.build
@@ -268,6 +268,7 @@ glib_sources = files(
   'gslist.c',
   'gstdio.c',
   'gstrfuncs.c',
+  'gstrfuncsprivate.h',
   'gstring.c',
   'gstringchunk.c',
   'gtestutils.c',
diff --git a/glib/tests/strfuncs.c b/glib/tests/strfuncs.c
index e1f9619c7..d968afff9 100644
--- a/glib/tests/strfuncs.c
+++ b/glib/tests/strfuncs.c
@@ -32,6 +32,8 @@
 #include <string.h>
 #include "glib.h"
 
+#include "gstrfuncsprivate.h"
+
 #if defined (_MSC_VER) && (_MSC_VER <= 1800)
 #define isnan(x) _isnan(x)
 
@@ -219,6 +221,26 @@ test_memdup (void)
   g_free (str_dup);
 }
 
+/* Testing g_memdup2() function with various positive and negative cases */
+static void
+test_memdup2 (void)
+{
+  gchar *str_dup = NULL;
+  const gchar *str = "The quick brown fox jumps over the lazy dog";
+
+  /* Testing negative cases */
+  g_assert_null (g_memdup2 (NULL, 1024));
+  g_assert_null (g_memdup2 (str, 0));
+  g_assert_null (g_memdup2 (NULL, 0));
+
+  /* Testing normal usage cases */
+  str_dup = g_memdup2 (str, strlen (str) + 1);
+  g_assert_nonnull (str_dup);
+  g_assert_cmpstr (str, ==, str_dup);
+
+  g_free (str_dup);
+}
+
 /* Testing g_strpcpy() function with various positive and negative cases */
 static void
 test_stpcpy (void)
@@ -2523,6 +2545,7 @@ main (int   argc,
   g_test_add_func ("/strfuncs/has-prefix", test_has_prefix);
   g_test_add_func ("/strfuncs/has-suffix", test_has_suffix);
   g_test_add_func ("/strfuncs/memdup", test_memdup);
+  g_test_add_func ("/strfuncs/memdup2", test_memdup2);
   g_test_add_func ("/strfuncs/stpcpy", test_stpcpy);
   g_test_add_func ("/strfuncs/str_match_string", test_str_match_string);
   g_test_add_func ("/strfuncs/str_tokenize_and_fold", test_str_tokenize_and_fold);
-- 
2.30.1