blob: 5e51872b3fc163af2fe82e6d7010b4aba08b612a [file] [log] [blame]
Andrey Ryabinin3f158012015-02-13 14:39:53 -08001/*
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>
Andrey Ryabinineae08dc2016-05-20 16:59:34 -070015#include <linux/mman.h>
16#include <linux/mm.h>
Andrey Ryabinin3f158012015-02-13 14:39:53 -080017#include <linux/printk.h>
18#include <linux/slab.h>
19#include <linux/string.h>
Andrey Ryabinineae08dc2016-05-20 16:59:34 -070020#include <linux/uaccess.h>
Andrey Ryabinin3f158012015-02-13 14:39:53 -080021#include <linux/module.h>
22
23static noinline void __init kmalloc_oob_right(void)
24{
25 char *ptr;
26 size_t size = 123;
27
28 pr_info("out-of-bounds to right\n");
29 ptr = kmalloc(size, GFP_KERNEL);
30 if (!ptr) {
31 pr_err("Allocation failed\n");
32 return;
33 }
34
35 ptr[size] = 'x';
36 kfree(ptr);
37}
38
39static noinline void __init kmalloc_oob_left(void)
40{
41 char *ptr;
42 size_t size = 15;
43
44 pr_info("out-of-bounds to left\n");
45 ptr = kmalloc(size, GFP_KERNEL);
46 if (!ptr) {
47 pr_err("Allocation failed\n");
48 return;
49 }
50
51 *ptr = *(ptr - 1);
52 kfree(ptr);
53}
54
55static noinline void __init kmalloc_node_oob_right(void)
56{
57 char *ptr;
58 size_t size = 4096;
59
60 pr_info("kmalloc_node(): out-of-bounds to right\n");
61 ptr = kmalloc_node(size, GFP_KERNEL, 0);
62 if (!ptr) {
63 pr_err("Allocation failed\n");
64 return;
65 }
66
67 ptr[size] = 0;
68 kfree(ptr);
69}
70
Alexander Potapenkoe6e83792016-03-25 14:21:56 -070071#ifdef CONFIG_SLUB
72static noinline void __init kmalloc_pagealloc_oob_right(void)
Andrey Ryabinin3f158012015-02-13 14:39:53 -080073{
74 char *ptr;
75 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
76
Alexander Potapenkoe6e83792016-03-25 14:21:56 -070077 /* Allocate a chunk that does not fit into a SLUB cache to trigger
78 * the page allocator fallback.
79 */
80 pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
81 ptr = kmalloc(size, GFP_KERNEL);
82 if (!ptr) {
83 pr_err("Allocation failed\n");
84 return;
85 }
86
87 ptr[size] = 0;
88 kfree(ptr);
89}
90#endif
91
92static noinline void __init kmalloc_large_oob_right(void)
93{
94 char *ptr;
95 size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
96 /* Allocate a chunk that is large enough, but still fits into a slab
97 * and does not trigger the page allocator fallback in SLUB.
98 */
Andrey Ryabinin3f158012015-02-13 14:39:53 -080099 pr_info("kmalloc large allocation: out-of-bounds to right\n");
100 ptr = kmalloc(size, GFP_KERNEL);
101 if (!ptr) {
102 pr_err("Allocation failed\n");
103 return;
104 }
105
106 ptr[size] = 0;
107 kfree(ptr);
108}
109
110static noinline void __init kmalloc_oob_krealloc_more(void)
111{
112 char *ptr1, *ptr2;
113 size_t size1 = 17;
114 size_t size2 = 19;
115
116 pr_info("out-of-bounds after krealloc more\n");
117 ptr1 = kmalloc(size1, GFP_KERNEL);
118 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
119 if (!ptr1 || !ptr2) {
120 pr_err("Allocation failed\n");
121 kfree(ptr1);
122 return;
123 }
124
125 ptr2[size2] = 'x';
126 kfree(ptr2);
127}
128
129static noinline void __init kmalloc_oob_krealloc_less(void)
130{
131 char *ptr1, *ptr2;
132 size_t size1 = 17;
133 size_t size2 = 15;
134
135 pr_info("out-of-bounds after krealloc less\n");
136 ptr1 = kmalloc(size1, GFP_KERNEL);
137 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
138 if (!ptr1 || !ptr2) {
139 pr_err("Allocation failed\n");
140 kfree(ptr1);
141 return;
142 }
Wang Long6b4a35f2015-09-09 15:37:22 -0700143 ptr2[size2] = 'x';
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800144 kfree(ptr2);
145}
146
147static noinline void __init kmalloc_oob_16(void)
148{
149 struct {
150 u64 words[2];
151 } *ptr1, *ptr2;
152
153 pr_info("kmalloc out-of-bounds for 16-bytes access\n");
154 ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
155 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
156 if (!ptr1 || !ptr2) {
157 pr_err("Allocation failed\n");
158 kfree(ptr1);
159 kfree(ptr2);
160 return;
161 }
162 *ptr1 = *ptr2;
163 kfree(ptr1);
164 kfree(ptr2);
165}
166
Wang Longf523e732015-11-05 18:51:15 -0800167static noinline void __init kmalloc_oob_memset_2(void)
168{
169 char *ptr;
170 size_t size = 8;
171
172 pr_info("out-of-bounds in memset2\n");
173 ptr = kmalloc(size, GFP_KERNEL);
174 if (!ptr) {
175 pr_err("Allocation failed\n");
176 return;
177 }
178
179 memset(ptr+7, 0, 2);
180 kfree(ptr);
181}
182
183static noinline void __init kmalloc_oob_memset_4(void)
184{
185 char *ptr;
186 size_t size = 8;
187
188 pr_info("out-of-bounds in memset4\n");
189 ptr = kmalloc(size, GFP_KERNEL);
190 if (!ptr) {
191 pr_err("Allocation failed\n");
192 return;
193 }
194
195 memset(ptr+5, 0, 4);
196 kfree(ptr);
197}
198
199
200static noinline void __init kmalloc_oob_memset_8(void)
201{
202 char *ptr;
203 size_t size = 8;
204
205 pr_info("out-of-bounds in memset8\n");
206 ptr = kmalloc(size, GFP_KERNEL);
207 if (!ptr) {
208 pr_err("Allocation failed\n");
209 return;
210 }
211
212 memset(ptr+1, 0, 8);
213 kfree(ptr);
214}
215
216static noinline void __init kmalloc_oob_memset_16(void)
217{
218 char *ptr;
219 size_t size = 16;
220
221 pr_info("out-of-bounds in memset16\n");
222 ptr = kmalloc(size, GFP_KERNEL);
223 if (!ptr) {
224 pr_err("Allocation failed\n");
225 return;
226 }
227
228 memset(ptr+1, 0, 16);
229 kfree(ptr);
230}
231
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800232static noinline void __init kmalloc_oob_in_memset(void)
233{
234 char *ptr;
235 size_t size = 666;
236
237 pr_info("out-of-bounds in memset\n");
238 ptr = kmalloc(size, GFP_KERNEL);
239 if (!ptr) {
240 pr_err("Allocation failed\n");
241 return;
242 }
243
244 memset(ptr, 0, size+5);
245 kfree(ptr);
246}
247
248static noinline void __init kmalloc_uaf(void)
249{
250 char *ptr;
251 size_t size = 10;
252
253 pr_info("use-after-free\n");
254 ptr = kmalloc(size, GFP_KERNEL);
255 if (!ptr) {
256 pr_err("Allocation failed\n");
257 return;
258 }
259
260 kfree(ptr);
261 *(ptr + 8) = 'x';
262}
263
264static noinline void __init kmalloc_uaf_memset(void)
265{
266 char *ptr;
267 size_t size = 33;
268
269 pr_info("use-after-free in memset\n");
270 ptr = kmalloc(size, GFP_KERNEL);
271 if (!ptr) {
272 pr_err("Allocation failed\n");
273 return;
274 }
275
276 kfree(ptr);
277 memset(ptr, 0, size);
278}
279
280static noinline void __init kmalloc_uaf2(void)
281{
282 char *ptr1, *ptr2;
283 size_t size = 43;
284
285 pr_info("use-after-free after another kmalloc\n");
286 ptr1 = kmalloc(size, GFP_KERNEL);
287 if (!ptr1) {
288 pr_err("Allocation failed\n");
289 return;
290 }
291
292 kfree(ptr1);
293 ptr2 = kmalloc(size, GFP_KERNEL);
294 if (!ptr2) {
295 pr_err("Allocation failed\n");
296 return;
297 }
298
299 ptr1[40] = 'x';
Alexander Potapenko9dcadd32016-03-25 14:22:11 -0700300 if (ptr1 == ptr2)
301 pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800302 kfree(ptr2);
303}
304
305static noinline void __init kmem_cache_oob(void)
306{
307 char *p;
308 size_t size = 200;
309 struct kmem_cache *cache = kmem_cache_create("test_cache",
310 size, 0,
311 0, NULL);
312 if (!cache) {
313 pr_err("Cache allocation failed\n");
314 return;
315 }
316 pr_info("out-of-bounds in kmem_cache_alloc\n");
317 p = kmem_cache_alloc(cache, GFP_KERNEL);
318 if (!p) {
319 pr_err("Allocation failed\n");
320 kmem_cache_destroy(cache);
321 return;
322 }
323
324 *p = p[size];
325 kmem_cache_free(cache, p);
326 kmem_cache_destroy(cache);
327}
328
329static char global_array[10];
330
331static noinline void __init kasan_global_oob(void)
332{
333 volatile int i = 3;
334 char *p = &global_array[ARRAY_SIZE(global_array) + i];
335
336 pr_info("out-of-bounds global variable\n");
337 *(volatile char *)p;
338}
339
340static noinline void __init kasan_stack_oob(void)
341{
342 char stack_array[10];
343 volatile int i = 0;
344 char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
345
346 pr_info("out-of-bounds on stack\n");
347 *(volatile char *)p;
348}
349
Alexander Potapenko96fe8052016-05-20 16:59:17 -0700350static noinline void __init ksize_unpoisons_memory(void)
351{
352 char *ptr;
353 size_t size = 123, real_size = size;
354
355 pr_info("ksize() unpoisons the whole allocated chunk\n");
356 ptr = kmalloc(size, GFP_KERNEL);
357 if (!ptr) {
358 pr_err("Allocation failed\n");
359 return;
360 }
361 real_size = ksize(ptr);
362 /* This access doesn't trigger an error. */
363 ptr[size] = 'x';
364 /* This one does. */
365 ptr[real_size] = 'y';
366 kfree(ptr);
367}
368
Andrey Ryabinineae08dc2016-05-20 16:59:34 -0700369static noinline void __init copy_user_test(void)
370{
371 char *kmem;
372 char __user *usermem;
373 size_t size = 10;
374 int unused;
375
376 kmem = kmalloc(size, GFP_KERNEL);
377 if (!kmem)
378 return;
379
380 usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
381 PROT_READ | PROT_WRITE | PROT_EXEC,
382 MAP_ANONYMOUS | MAP_PRIVATE, 0);
383 if (IS_ERR(usermem)) {
384 pr_err("Failed to allocate user memory\n");
385 kfree(kmem);
386 return;
387 }
388
389 pr_info("out-of-bounds in copy_from_user()\n");
390 unused = copy_from_user(kmem, usermem, size + 1);
391
392 pr_info("out-of-bounds in copy_to_user()\n");
393 unused = copy_to_user(usermem, kmem, size + 1);
394
395 pr_info("out-of-bounds in __copy_from_user()\n");
396 unused = __copy_from_user(kmem, usermem, size + 1);
397
398 pr_info("out-of-bounds in __copy_to_user()\n");
399 unused = __copy_to_user(usermem, kmem, size + 1);
400
401 pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
402 unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
403
404 pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
405 unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
406
407 pr_info("out-of-bounds in strncpy_from_user()\n");
408 unused = strncpy_from_user(kmem, usermem, size + 1);
409
410 vm_munmap((unsigned long)usermem, PAGE_SIZE);
411 kfree(kmem);
412}
413
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800414static int __init kmalloc_tests_init(void)
415{
416 kmalloc_oob_right();
417 kmalloc_oob_left();
418 kmalloc_node_oob_right();
Alexander Potapenkoe6e83792016-03-25 14:21:56 -0700419#ifdef CONFIG_SLUB
420 kmalloc_pagealloc_oob_right();
421#endif
Wang Long9789d8e2015-09-09 15:37:19 -0700422 kmalloc_large_oob_right();
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800423 kmalloc_oob_krealloc_more();
424 kmalloc_oob_krealloc_less();
425 kmalloc_oob_16();
426 kmalloc_oob_in_memset();
Wang Longf523e732015-11-05 18:51:15 -0800427 kmalloc_oob_memset_2();
428 kmalloc_oob_memset_4();
429 kmalloc_oob_memset_8();
430 kmalloc_oob_memset_16();
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800431 kmalloc_uaf();
432 kmalloc_uaf_memset();
433 kmalloc_uaf2();
434 kmem_cache_oob();
435 kasan_stack_oob();
436 kasan_global_oob();
Alexander Potapenko96fe8052016-05-20 16:59:17 -0700437 ksize_unpoisons_memory();
Andrey Ryabinineae08dc2016-05-20 16:59:34 -0700438 copy_user_test();
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800439 return -EAGAIN;
440}
441
442module_init(kmalloc_tests_init);
443MODULE_LICENSE("GPL");