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
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
|
/*
*
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
* Author: Andrey Ryabinin <a.ryabinin@samsung.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
#include <linux/kernel.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
static noinline void __init kmalloc_oob_right(void)
{
char *ptr;
size_t size = 123;
pr_info("out-of-bounds to right\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
return;
}
ptr[size] = 'x';
kfree(ptr);
}
static noinline void __init kmalloc_oob_left(void)
{
char *ptr;
size_t size = 15;
pr_info("out-of-bounds to left\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
return;
}
*ptr = *(ptr - 1);
kfree(ptr);
}
static noinline void __init kmalloc_node_oob_right(void)
{
char *ptr;
size_t size = 4096;
pr_info("kmalloc_node(): out-of-bounds to right\n");
ptr = kmalloc_node(size, GFP_KERNEL, 0);
if (!ptr) {
pr_err("Allocation failed\n");
return;
}
ptr[size] = 0;
kfree(ptr);
}
static noinline void __init kmalloc_large_oob_rigth(void)
{
char *ptr;
size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
pr_info("kmalloc large allocation: out-of-bounds to right\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
return;
}
ptr[size] = 0;
kfree(ptr);
}
static noinline void __init kmalloc_oob_krealloc_more(void)
{
char *ptr1, *ptr2;
size_t size1 = 17;
size_t size2 = 19;
pr_info("out-of-bounds after krealloc more\n");
ptr1 = kmalloc(size1, GFP_KERNEL);
ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
if (!ptr1 || !ptr2) {
pr_err("Allocation failed\n");
kfree(ptr1);
return;
}
ptr2[size2] = 'x';
kfree(ptr2);
}
static noinline void __init kmalloc_oob_krealloc_less(void)
{
char *ptr1, *ptr2;
size_t size1 = 17;
size_t size2 = 15;
pr_info("out-of-bounds after krealloc less\n");
ptr1 = kmalloc(size1, GFP_KERNEL);
ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
if (!ptr1 || !ptr2) {
pr_err("Allocation failed\n");
kfree(ptr1);
return;
}
ptr2[size1] = 'x';
kfree(ptr2);
}
static noinline void __init kmalloc_oob_16(void)
{
struct {
u64 words[2];
} *ptr1, *ptr2;
pr_info("kmalloc out-of-bounds for 16-bytes access\n");
ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
if (!ptr1 || !ptr2) {
pr_err("Allocation failed\n");
kfree(ptr1);
kfree(ptr2);
return;
}
*ptr1 = *ptr2;
kfree(ptr1);
kfree(ptr2);
}
static noinline void __init kmalloc_oob_in_memset(void)
{
char *ptr;
size_t size = 666;
pr_info("out-of-bounds in memset\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
return;
}
memset(ptr, 0, size+5);
kfree(ptr);
}
static noinline void __init kmalloc_uaf(void)
{
char *ptr;
size_t size = 10;
pr_info("use-after-free\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
return;
}
kfree(ptr);
*(ptr + 8) = 'x';
}
static noinline void __init kmalloc_uaf_memset(void)
{
char *ptr;
size_t size = 33;
pr_info("use-after-free in memset\n");
ptr = kmalloc(size, GFP_KERNEL);
if (!ptr) {
pr_err("Allocation failed\n");
return;
}
kfree(ptr);
memset(ptr, 0, size);
}
static noinline void __init kmalloc_uaf2(void)
{
char *ptr1, *ptr2;
size_t size = 43;
pr_info("use-after-free after another kmalloc\n");
ptr1 = kmalloc(size, GFP_KERNEL);
if (!ptr1) {
pr_err("Allocation failed\n");
return;
}
kfree(ptr1);
ptr2 = kmalloc(size, GFP_KERNEL);
if (!ptr2) {
pr_err("Allocation failed\n");
return;
}
ptr1[40] = 'x';
kfree(ptr2);
}
static noinline void __init kmem_cache_oob(void)
{
char *p;
size_t size = 200;
struct kmem_cache *cache = kmem_cache_create("test_cache",
size, 0,
0, NULL);
if (!cache) {
pr_err("Cache allocation failed\n");
return;
}
pr_info("out-of-bounds in kmem_cache_alloc\n");
p = kmem_cache_alloc(cache, GFP_KERNEL);
if (!p) {
pr_err("Allocation failed\n");
kmem_cache_destroy(cache);
return;
}
*p = p[size];
kmem_cache_free(cache, p);
kmem_cache_destroy(cache);
}
static char global_array[10];
static noinline void __init kasan_global_oob(void)
{
volatile int i = 3;
char *p = &global_array[ARRAY_SIZE(global_array) + i];
pr_info("out-of-bounds global variable\n");
*(volatile char *)p;
}
static noinline void __init kasan_stack_oob(void)
{
char stack_array[10];
volatile int i = 0;
char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
pr_info("out-of-bounds on stack\n");
*(volatile char *)p;
}
static int __init kmalloc_tests_init(void)
{
kmalloc_oob_right();
kmalloc_oob_left();
kmalloc_node_oob_right();
kmalloc_large_oob_rigth();
kmalloc_oob_krealloc_more();
kmalloc_oob_krealloc_less();
kmalloc_oob_16();
kmalloc_oob_in_memset();
kmalloc_uaf();
kmalloc_uaf_memset();
kmalloc_uaf2();
kmem_cache_oob();
kasan_stack_oob();
kasan_global_oob();
return -EAGAIN;
}
module_init(kmalloc_tests_init);
MODULE_LICENSE("GPL");
|
