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
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
From d0f05d1e39adb336a8bbccbc276a344e6ff427e3 Mon Sep 17 00:00:00 2001
From: Florian Weimer <fweimer@redhat.com>
Date: Thu, 28 Jan 2016 13:59:11 +0100
Subject: [PATCH] Improve check against integer wraparound in hcreate_r [BZ
#18240]
CVE: CVE-2015-8778
Improve check against integer wraparound in hcreate_r [BZ #18240]
This is an integer overflow in hcreate and hcreate_r which can result in
an out-of-bound memory access. This could lead to application crashes
or, potentially, arbitrary code execution.
Upstream-Status: Backport [2.23]
(cherry-picked from commit bae7c7c7, 4bd228c8)
Signed-off-by: Yuanjie Huang <yuanjie.huang@windriver.com>
---
ChangeLog | 6 +++++
NEWS | 2 +-
misc/Makefile | 2 +-
misc/bug18240.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
misc/hsearch_r.c | 28 ++++++++++++---------
5 files changed, 100 insertions(+), 13 deletions(-)
create mode 100644 misc/bug18240.c
diff --git a/ChangeLog b/ChangeLog
index b7701d1..a9dc8a2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2016-01-27 Paul Eggert <eggert@cs.ucla.edu>
+
+ [BZ #18240]
+ * misc/hsearch_r.c (isprime, __hcreate_r): Protect against
+ unsigned int wraparound.
+
2016-02-15 Carlos O'Donell <carlos@redhat.com>
[BZ #18665]
diff --git a/NEWS b/NEWS
index cda7a73..fd77c27 100644
--- a/NEWS
+++ b/NEWS
@@ -9,7 +9,7 @@ Version 2.22.1
* The following bugs are resolved with this release:
- 18778, 18781, 18787, 17905.
+ 18240, 18778, 18781, 18787, 17905.
Version 2.22
diff --git a/misc/Makefile b/misc/Makefile
index e6b7c23..463a238 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -83,7 +83,7 @@ install-lib := libg.a
gpl2lgpl := error.c error.h
tests := tst-dirname tst-tsearch tst-fdset tst-mntent tst-hsearch \
- tst-pselect tst-insremque tst-mntent2 bug-hsearch1
+ tst-pselect tst-insremque tst-mntent2 bug-hsearch1 bug18240
tests-$(OPTION_POSIX_WIDE_CHAR_DEVICE_IO) += tst-error1
tests-$(OPTION_EGLIBC_FCVT) += tst-efgcvt
ifeq ($(run-built-tests),yes)
diff --git a/misc/bug18240.c b/misc/bug18240.c
new file mode 100644
index 0000000..4b26865
--- /dev/null
+++ b/misc/bug18240.c
@@ -0,0 +1,75 @@
+/* Test integer wraparound in hcreate.
+ Copyright (C) 2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C 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.
+
+ The GNU C 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 the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <errno.h>
+#include <limits.h>
+#include <search.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static void
+test_size (size_t size)
+{
+ int res = hcreate (size);
+ if (res == 0)
+ {
+ if (errno == ENOMEM)
+ return;
+ printf ("error: hcreate (%zu): %m\n", size);
+ exit (1);
+ }
+ char *keys[100];
+ for (int i = 0; i < 100; ++i)
+ {
+ if (asprintf (keys + i, "%d", i) < 0)
+ {
+ printf ("error: asprintf: %m\n");
+ exit (1);
+ }
+ ENTRY e = { keys[i], (char *) "value" };
+ if (hsearch (e, ENTER) == NULL)
+ {
+ printf ("error: hsearch (\"%s\"): %m\n", keys[i]);
+ exit (1);
+ }
+ }
+ hdestroy ();
+
+ for (int i = 0; i < 100; ++i)
+ free (keys[i]);
+}
+
+static int
+do_test (void)
+{
+ test_size (500);
+ test_size (-1);
+ test_size (-3);
+ test_size (INT_MAX - 2);
+ test_size (INT_MAX - 1);
+ test_size (INT_MAX);
+ test_size (((unsigned) INT_MAX) + 1);
+ test_size (UINT_MAX - 2);
+ test_size (UINT_MAX - 1);
+ test_size (UINT_MAX);
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/misc/hsearch_r.c b/misc/hsearch_r.c
index 9f55e84..6000ce2 100644
--- a/misc/hsearch_r.c
+++ b/misc/hsearch_r.c
@@ -46,15 +46,12 @@ static int
isprime (unsigned int number)
{
/* no even number will be passed */
- unsigned int div = 3;
-
- while (div * div < number && number % div != 0)
- div += 2;
-
- return number % div != 0;
+ for (unsigned int div = 3; div <= number / div; div += 2)
+ if (number % div == 0)
+ return 0;
+ return 1;
}
-
/* Before using the hash table we must allocate memory for it.
Test for an existing table are done. We allocate one element
more as the found prime number says. This is done for more effective
@@ -81,10 +78,19 @@ __hcreate_r (nel, htab)
use will not work. */
if (nel < 3)
nel = 3;
- /* Change nel to the first prime number not smaller as nel. */
- nel |= 1; /* make odd */
- while (!isprime (nel))
- nel += 2;
+
+ /* Change nel to the first prime number in the range [nel, UINT_MAX - 2],
+ The '- 2' means 'nel += 2' cannot overflow. */
+ for (nel |= 1; ; nel += 2)
+ {
+ if (UINT_MAX - 2 < nel)
+ {
+ __set_errno (ENOMEM);
+ return 0;
+ }
+ if (isprime (nel))
+ break;
+ }
htab->size = nel;
htab->filled = 0;
--
2.7.4
|
