1 /*
2 *
3 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
4 * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 */
11
12 #define pr_fmt(fmt) "kasan test: %s " fmt, __func__
13
14 #include <linux/kernel.h>
15 #include <linux/printk.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include <linux/module.h>
19
kmalloc_oob_right(void)20 static noinline void __init kmalloc_oob_right(void)
21 {
22 char *ptr;
23 size_t size = 123;
24
25 pr_info("out-of-bounds to right\n");
26 ptr = kmalloc(size, GFP_KERNEL);
27 if (!ptr) {
28 pr_err("Allocation failed\n");
29 return;
30 }
31
32 ptr[size] = 'x';
33 kfree(ptr);
34 }
35
kmalloc_oob_left(void)36 static noinline void __init kmalloc_oob_left(void)
37 {
38 char *ptr;
39 size_t size = 15;
40
41 pr_info("out-of-bounds to left\n");
42 ptr = kmalloc(size, GFP_KERNEL);
43 if (!ptr) {
44 pr_err("Allocation failed\n");
45 return;
46 }
47
48 *ptr = *(ptr - 1);
49 kfree(ptr);
50 }
51
kmalloc_node_oob_right(void)52 static noinline void __init kmalloc_node_oob_right(void)
53 {
54 char *ptr;
55 size_t size = 4096;
56
57 pr_info("kmalloc_node(): out-of-bounds to right\n");
58 ptr = kmalloc_node(size, GFP_KERNEL, 0);
59 if (!ptr) {
60 pr_err("Allocation failed\n");
61 return;
62 }
63
64 ptr[size] = 0;
65 kfree(ptr);
66 }
67
kmalloc_large_oob_right(void)68 static noinline void __init kmalloc_large_oob_right(void)
69 {
70 char *ptr;
71 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
72
73 pr_info("kmalloc large allocation: out-of-bounds to right\n");
74 ptr = kmalloc(size, GFP_KERNEL);
75 if (!ptr) {
76 pr_err("Allocation failed\n");
77 return;
78 }
79
80 ptr[size] = 0;
81 kfree(ptr);
82 }
83
kmalloc_oob_krealloc_more(void)84 static noinline void __init kmalloc_oob_krealloc_more(void)
85 {
86 char *ptr1, *ptr2;
87 size_t size1 = 17;
88 size_t size2 = 19;
89
90 pr_info("out-of-bounds after krealloc more\n");
91 ptr1 = kmalloc(size1, GFP_KERNEL);
92 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
93 if (!ptr1 || !ptr2) {
94 pr_err("Allocation failed\n");
95 kfree(ptr1);
96 return;
97 }
98
99 ptr2[size2] = 'x';
100 kfree(ptr2);
101 }
102
kmalloc_oob_krealloc_less(void)103 static noinline void __init kmalloc_oob_krealloc_less(void)
104 {
105 char *ptr1, *ptr2;
106 size_t size1 = 17;
107 size_t size2 = 15;
108
109 pr_info("out-of-bounds after krealloc less\n");
110 ptr1 = kmalloc(size1, GFP_KERNEL);
111 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
112 if (!ptr1 || !ptr2) {
113 pr_err("Allocation failed\n");
114 kfree(ptr1);
115 return;
116 }
117 ptr2[size2] = 'x';
118 kfree(ptr2);
119 }
120
kmalloc_oob_16(void)121 static noinline void __init kmalloc_oob_16(void)
122 {
123 struct {
124 u64 words[2];
125 } *ptr1, *ptr2;
126
127 pr_info("kmalloc out-of-bounds for 16-bytes access\n");
128 ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
129 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
130 if (!ptr1 || !ptr2) {
131 pr_err("Allocation failed\n");
132 kfree(ptr1);
133 kfree(ptr2);
134 return;
135 }
136 *ptr1 = *ptr2;
137 kfree(ptr1);
138 kfree(ptr2);
139 }
140
kmalloc_oob_memset_2(void)141 static noinline void __init kmalloc_oob_memset_2(void)
142 {
143 char *ptr;
144 size_t size = 8;
145
146 pr_info("out-of-bounds in memset2\n");
147 ptr = kmalloc(size, GFP_KERNEL);
148 if (!ptr) {
149 pr_err("Allocation failed\n");
150 return;
151 }
152
153 memset(ptr+7, 0, 2);
154 kfree(ptr);
155 }
156
kmalloc_oob_memset_4(void)157 static noinline void __init kmalloc_oob_memset_4(void)
158 {
159 char *ptr;
160 size_t size = 8;
161
162 pr_info("out-of-bounds in memset4\n");
163 ptr = kmalloc(size, GFP_KERNEL);
164 if (!ptr) {
165 pr_err("Allocation failed\n");
166 return;
167 }
168
169 memset(ptr+5, 0, 4);
170 kfree(ptr);
171 }
172
173
kmalloc_oob_memset_8(void)174 static noinline void __init kmalloc_oob_memset_8(void)
175 {
176 char *ptr;
177 size_t size = 8;
178
179 pr_info("out-of-bounds in memset8\n");
180 ptr = kmalloc(size, GFP_KERNEL);
181 if (!ptr) {
182 pr_err("Allocation failed\n");
183 return;
184 }
185
186 memset(ptr+1, 0, 8);
187 kfree(ptr);
188 }
189
kmalloc_oob_memset_16(void)190 static noinline void __init kmalloc_oob_memset_16(void)
191 {
192 char *ptr;
193 size_t size = 16;
194
195 pr_info("out-of-bounds in memset16\n");
196 ptr = kmalloc(size, GFP_KERNEL);
197 if (!ptr) {
198 pr_err("Allocation failed\n");
199 return;
200 }
201
202 memset(ptr+1, 0, 16);
203 kfree(ptr);
204 }
205
kmalloc_oob_in_memset(void)206 static noinline void __init kmalloc_oob_in_memset(void)
207 {
208 char *ptr;
209 size_t size = 666;
210
211 pr_info("out-of-bounds in memset\n");
212 ptr = kmalloc(size, GFP_KERNEL);
213 if (!ptr) {
214 pr_err("Allocation failed\n");
215 return;
216 }
217
218 memset(ptr, 0, size+5);
219 kfree(ptr);
220 }
221
kmalloc_uaf(void)222 static noinline void __init kmalloc_uaf(void)
223 {
224 char *ptr;
225 size_t size = 10;
226
227 pr_info("use-after-free\n");
228 ptr = kmalloc(size, GFP_KERNEL);
229 if (!ptr) {
230 pr_err("Allocation failed\n");
231 return;
232 }
233
234 kfree(ptr);
235 *(ptr + 8) = 'x';
236 }
237
kmalloc_uaf_memset(void)238 static noinline void __init kmalloc_uaf_memset(void)
239 {
240 char *ptr;
241 size_t size = 33;
242
243 pr_info("use-after-free in memset\n");
244 ptr = kmalloc(size, GFP_KERNEL);
245 if (!ptr) {
246 pr_err("Allocation failed\n");
247 return;
248 }
249
250 kfree(ptr);
251 memset(ptr, 0, size);
252 }
253
kmalloc_uaf2(void)254 static noinline void __init kmalloc_uaf2(void)
255 {
256 char *ptr1, *ptr2;
257 size_t size = 43;
258
259 pr_info("use-after-free after another kmalloc\n");
260 ptr1 = kmalloc(size, GFP_KERNEL);
261 if (!ptr1) {
262 pr_err("Allocation failed\n");
263 return;
264 }
265
266 kfree(ptr1);
267 ptr2 = kmalloc(size, GFP_KERNEL);
268 if (!ptr2) {
269 pr_err("Allocation failed\n");
270 return;
271 }
272
273 ptr1[40] = 'x';
274 kfree(ptr2);
275 }
276
kmem_cache_oob(void)277 static noinline void __init kmem_cache_oob(void)
278 {
279 char *p;
280 size_t size = 200;
281 struct kmem_cache *cache = kmem_cache_create("test_cache",
282 size, 0,
283 0, NULL);
284 if (!cache) {
285 pr_err("Cache allocation failed\n");
286 return;
287 }
288 pr_info("out-of-bounds in kmem_cache_alloc\n");
289 p = kmem_cache_alloc(cache, GFP_KERNEL);
290 if (!p) {
291 pr_err("Allocation failed\n");
292 kmem_cache_destroy(cache);
293 return;
294 }
295
296 *p = p[size];
297 kmem_cache_free(cache, p);
298 kmem_cache_destroy(cache);
299 }
300
301 static char global_array[10];
302
kasan_global_oob(void)303 static noinline void __init kasan_global_oob(void)
304 {
305 volatile int i = 3;
306 char *p = &global_array[ARRAY_SIZE(global_array) + i];
307
308 pr_info("out-of-bounds global variable\n");
309 *(volatile char *)p;
310 }
311
kasan_stack_oob(void)312 static noinline void __init kasan_stack_oob(void)
313 {
314 char stack_array[10];
315 volatile int i = 0;
316 char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
317
318 pr_info("out-of-bounds on stack\n");
319 *(volatile char *)p;
320 }
321
kmalloc_tests_init(void)322 static int __init kmalloc_tests_init(void)
323 {
324 kmalloc_oob_right();
325 kmalloc_oob_left();
326 kmalloc_node_oob_right();
327 kmalloc_large_oob_right();
328 kmalloc_oob_krealloc_more();
329 kmalloc_oob_krealloc_less();
330 kmalloc_oob_16();
331 kmalloc_oob_in_memset();
332 kmalloc_oob_memset_2();
333 kmalloc_oob_memset_4();
334 kmalloc_oob_memset_8();
335 kmalloc_oob_memset_16();
336 kmalloc_uaf();
337 kmalloc_uaf_memset();
338 kmalloc_uaf2();
339 kmem_cache_oob();
340 kasan_stack_oob();
341 kasan_global_oob();
342 return -EAGAIN;
343 }
344
345 module_init(kmalloc_tests_init);
346 MODULE_LICENSE("GPL");
347