blob: fbdf87920093b9b1dbd94e4b370a24e43d6bb8f7 [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
Dmitry Vyukov828347f2016-11-30 15:54:16 -080023/*
24 * Note: test functions are marked noinline so that their names appear in
25 * reports.
26 */
27
Andrey Ryabinin3f158012015-02-13 14:39:53 -080028static noinline void __init kmalloc_oob_right(void)
29{
30 char *ptr;
31 size_t size = 123;
32
33 pr_info("out-of-bounds to right\n");
34 ptr = kmalloc(size, GFP_KERNEL);
35 if (!ptr) {
36 pr_err("Allocation failed\n");
37 return;
38 }
39
40 ptr[size] = 'x';
41 kfree(ptr);
42}
43
44static noinline void __init kmalloc_oob_left(void)
45{
46 char *ptr;
47 size_t size = 15;
48
49 pr_info("out-of-bounds to left\n");
50 ptr = kmalloc(size, GFP_KERNEL);
51 if (!ptr) {
52 pr_err("Allocation failed\n");
53 return;
54 }
55
56 *ptr = *(ptr - 1);
57 kfree(ptr);
58}
59
60static noinline void __init kmalloc_node_oob_right(void)
61{
62 char *ptr;
63 size_t size = 4096;
64
65 pr_info("kmalloc_node(): out-of-bounds to right\n");
66 ptr = kmalloc_node(size, GFP_KERNEL, 0);
67 if (!ptr) {
68 pr_err("Allocation failed\n");
69 return;
70 }
71
72 ptr[size] = 0;
73 kfree(ptr);
74}
75
Alexander Potapenkoe6e83792016-03-25 14:21:56 -070076#ifdef CONFIG_SLUB
77static noinline void __init kmalloc_pagealloc_oob_right(void)
Andrey Ryabinin3f158012015-02-13 14:39:53 -080078{
79 char *ptr;
80 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
81
Alexander Potapenkoe6e83792016-03-25 14:21:56 -070082 /* Allocate a chunk that does not fit into a SLUB cache to trigger
83 * the page allocator fallback.
84 */
85 pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
86 ptr = kmalloc(size, GFP_KERNEL);
87 if (!ptr) {
88 pr_err("Allocation failed\n");
89 return;
90 }
91
92 ptr[size] = 0;
93 kfree(ptr);
94}
95#endif
96
97static noinline void __init kmalloc_large_oob_right(void)
98{
99 char *ptr;
100 size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
101 /* Allocate a chunk that is large enough, but still fits into a slab
102 * and does not trigger the page allocator fallback in SLUB.
103 */
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800104 pr_info("kmalloc large allocation: out-of-bounds to right\n");
105 ptr = kmalloc(size, GFP_KERNEL);
106 if (!ptr) {
107 pr_err("Allocation failed\n");
108 return;
109 }
110
111 ptr[size] = 0;
112 kfree(ptr);
113}
114
115static noinline void __init kmalloc_oob_krealloc_more(void)
116{
117 char *ptr1, *ptr2;
118 size_t size1 = 17;
119 size_t size2 = 19;
120
121 pr_info("out-of-bounds after krealloc more\n");
122 ptr1 = kmalloc(size1, GFP_KERNEL);
123 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
124 if (!ptr1 || !ptr2) {
125 pr_err("Allocation failed\n");
126 kfree(ptr1);
127 return;
128 }
129
130 ptr2[size2] = 'x';
131 kfree(ptr2);
132}
133
134static noinline void __init kmalloc_oob_krealloc_less(void)
135{
136 char *ptr1, *ptr2;
137 size_t size1 = 17;
138 size_t size2 = 15;
139
140 pr_info("out-of-bounds after krealloc less\n");
141 ptr1 = kmalloc(size1, GFP_KERNEL);
142 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
143 if (!ptr1 || !ptr2) {
144 pr_err("Allocation failed\n");
145 kfree(ptr1);
146 return;
147 }
Wang Long6b4a35f2015-09-09 15:37:22 -0700148 ptr2[size2] = 'x';
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800149 kfree(ptr2);
150}
151
152static noinline void __init kmalloc_oob_16(void)
153{
154 struct {
155 u64 words[2];
156 } *ptr1, *ptr2;
157
158 pr_info("kmalloc out-of-bounds for 16-bytes access\n");
159 ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
160 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
161 if (!ptr1 || !ptr2) {
162 pr_err("Allocation failed\n");
163 kfree(ptr1);
164 kfree(ptr2);
165 return;
166 }
167 *ptr1 = *ptr2;
168 kfree(ptr1);
169 kfree(ptr2);
170}
171
Wang Longf523e732015-11-05 18:51:15 -0800172static noinline void __init kmalloc_oob_memset_2(void)
173{
174 char *ptr;
175 size_t size = 8;
176
177 pr_info("out-of-bounds in memset2\n");
178 ptr = kmalloc(size, GFP_KERNEL);
179 if (!ptr) {
180 pr_err("Allocation failed\n");
181 return;
182 }
183
184 memset(ptr+7, 0, 2);
185 kfree(ptr);
186}
187
188static noinline void __init kmalloc_oob_memset_4(void)
189{
190 char *ptr;
191 size_t size = 8;
192
193 pr_info("out-of-bounds in memset4\n");
194 ptr = kmalloc(size, GFP_KERNEL);
195 if (!ptr) {
196 pr_err("Allocation failed\n");
197 return;
198 }
199
200 memset(ptr+5, 0, 4);
201 kfree(ptr);
202}
203
204
205static noinline void __init kmalloc_oob_memset_8(void)
206{
207 char *ptr;
208 size_t size = 8;
209
210 pr_info("out-of-bounds in memset8\n");
211 ptr = kmalloc(size, GFP_KERNEL);
212 if (!ptr) {
213 pr_err("Allocation failed\n");
214 return;
215 }
216
217 memset(ptr+1, 0, 8);
218 kfree(ptr);
219}
220
221static noinline void __init kmalloc_oob_memset_16(void)
222{
223 char *ptr;
224 size_t size = 16;
225
226 pr_info("out-of-bounds in memset16\n");
227 ptr = kmalloc(size, GFP_KERNEL);
228 if (!ptr) {
229 pr_err("Allocation failed\n");
230 return;
231 }
232
233 memset(ptr+1, 0, 16);
234 kfree(ptr);
235}
236
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800237static noinline void __init kmalloc_oob_in_memset(void)
238{
239 char *ptr;
240 size_t size = 666;
241
242 pr_info("out-of-bounds in memset\n");
243 ptr = kmalloc(size, GFP_KERNEL);
244 if (!ptr) {
245 pr_err("Allocation failed\n");
246 return;
247 }
248
249 memset(ptr, 0, size+5);
250 kfree(ptr);
251}
252
253static noinline void __init kmalloc_uaf(void)
254{
255 char *ptr;
256 size_t size = 10;
257
258 pr_info("use-after-free\n");
259 ptr = kmalloc(size, GFP_KERNEL);
260 if (!ptr) {
261 pr_err("Allocation failed\n");
262 return;
263 }
264
265 kfree(ptr);
266 *(ptr + 8) = 'x';
267}
268
269static noinline void __init kmalloc_uaf_memset(void)
270{
271 char *ptr;
272 size_t size = 33;
273
274 pr_info("use-after-free in memset\n");
275 ptr = kmalloc(size, GFP_KERNEL);
276 if (!ptr) {
277 pr_err("Allocation failed\n");
278 return;
279 }
280
281 kfree(ptr);
282 memset(ptr, 0, size);
283}
284
285static noinline void __init kmalloc_uaf2(void)
286{
287 char *ptr1, *ptr2;
288 size_t size = 43;
289
290 pr_info("use-after-free after another kmalloc\n");
291 ptr1 = kmalloc(size, GFP_KERNEL);
292 if (!ptr1) {
293 pr_err("Allocation failed\n");
294 return;
295 }
296
297 kfree(ptr1);
298 ptr2 = kmalloc(size, GFP_KERNEL);
299 if (!ptr2) {
300 pr_err("Allocation failed\n");
301 return;
302 }
303
304 ptr1[40] = 'x';
Alexander Potapenko9dcadd32016-03-25 14:22:11 -0700305 if (ptr1 == ptr2)
306 pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800307 kfree(ptr2);
308}
309
310static noinline void __init kmem_cache_oob(void)
311{
312 char *p;
313 size_t size = 200;
314 struct kmem_cache *cache = kmem_cache_create("test_cache",
315 size, 0,
316 0, NULL);
317 if (!cache) {
318 pr_err("Cache allocation failed\n");
319 return;
320 }
321 pr_info("out-of-bounds in kmem_cache_alloc\n");
322 p = kmem_cache_alloc(cache, GFP_KERNEL);
323 if (!p) {
324 pr_err("Allocation failed\n");
325 kmem_cache_destroy(cache);
326 return;
327 }
328
329 *p = p[size];
330 kmem_cache_free(cache, p);
331 kmem_cache_destroy(cache);
332}
333
334static char global_array[10];
335
336static noinline void __init kasan_global_oob(void)
337{
338 volatile int i = 3;
339 char *p = &global_array[ARRAY_SIZE(global_array) + i];
340
341 pr_info("out-of-bounds global variable\n");
342 *(volatile char *)p;
343}
344
345static noinline void __init kasan_stack_oob(void)
346{
347 char stack_array[10];
348 volatile int i = 0;
349 char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
350
351 pr_info("out-of-bounds on stack\n");
352 *(volatile char *)p;
353}
354
Alexander Potapenko96fe8052016-05-20 16:59:17 -0700355static noinline void __init ksize_unpoisons_memory(void)
356{
357 char *ptr;
358 size_t size = 123, real_size = size;
359
360 pr_info("ksize() unpoisons the whole allocated chunk\n");
361 ptr = kmalloc(size, GFP_KERNEL);
362 if (!ptr) {
363 pr_err("Allocation failed\n");
364 return;
365 }
366 real_size = ksize(ptr);
367 /* This access doesn't trigger an error. */
368 ptr[size] = 'x';
369 /* This one does. */
370 ptr[real_size] = 'y';
371 kfree(ptr);
372}
373
Andrey Ryabinineae08dc2016-05-20 16:59:34 -0700374static noinline void __init copy_user_test(void)
375{
376 char *kmem;
377 char __user *usermem;
378 size_t size = 10;
379 int unused;
380
381 kmem = kmalloc(size, GFP_KERNEL);
382 if (!kmem)
383 return;
384
385 usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
386 PROT_READ | PROT_WRITE | PROT_EXEC,
387 MAP_ANONYMOUS | MAP_PRIVATE, 0);
388 if (IS_ERR(usermem)) {
389 pr_err("Failed to allocate user memory\n");
390 kfree(kmem);
391 return;
392 }
393
394 pr_info("out-of-bounds in copy_from_user()\n");
395 unused = copy_from_user(kmem, usermem, size + 1);
396
397 pr_info("out-of-bounds in copy_to_user()\n");
398 unused = copy_to_user(usermem, kmem, size + 1);
399
400 pr_info("out-of-bounds in __copy_from_user()\n");
401 unused = __copy_from_user(kmem, usermem, size + 1);
402
403 pr_info("out-of-bounds in __copy_to_user()\n");
404 unused = __copy_to_user(usermem, kmem, size + 1);
405
406 pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
407 unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
408
409 pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
410 unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
411
412 pr_info("out-of-bounds in strncpy_from_user()\n");
413 unused = strncpy_from_user(kmem, usermem, size + 1);
414
415 vm_munmap((unsigned long)usermem, PAGE_SIZE);
416 kfree(kmem);
417}
418
Dmitry Vyukov828347f2016-11-30 15:54:16 -0800419static noinline void __init use_after_scope_test(void)
420{
421 volatile char *volatile p;
422
423 pr_info("use-after-scope on int\n");
424 {
425 int local = 0;
426
427 p = (char *)&local;
428 }
429 p[0] = 1;
430 p[3] = 1;
431
432 pr_info("use-after-scope on array\n");
433 {
434 char local[1024] = {0};
435
436 p = local;
437 }
438 p[0] = 1;
439 p[1023] = 1;
440}
441
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800442static int __init kmalloc_tests_init(void)
443{
444 kmalloc_oob_right();
445 kmalloc_oob_left();
446 kmalloc_node_oob_right();
Alexander Potapenkoe6e83792016-03-25 14:21:56 -0700447#ifdef CONFIG_SLUB
448 kmalloc_pagealloc_oob_right();
449#endif
Wang Long9789d8e2015-09-09 15:37:19 -0700450 kmalloc_large_oob_right();
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800451 kmalloc_oob_krealloc_more();
452 kmalloc_oob_krealloc_less();
453 kmalloc_oob_16();
454 kmalloc_oob_in_memset();
Wang Longf523e732015-11-05 18:51:15 -0800455 kmalloc_oob_memset_2();
456 kmalloc_oob_memset_4();
457 kmalloc_oob_memset_8();
458 kmalloc_oob_memset_16();
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800459 kmalloc_uaf();
460 kmalloc_uaf_memset();
461 kmalloc_uaf2();
462 kmem_cache_oob();
463 kasan_stack_oob();
464 kasan_global_oob();
Alexander Potapenko96fe8052016-05-20 16:59:17 -0700465 ksize_unpoisons_memory();
Andrey Ryabinineae08dc2016-05-20 16:59:34 -0700466 copy_user_test();
Dmitry Vyukov828347f2016-11-30 15:54:16 -0800467 use_after_scope_test();
Andrey Ryabinin3f158012015-02-13 14:39:53 -0800468 return -EAGAIN;
469}
470
471module_init(kmalloc_tests_init);
472MODULE_LICENSE("GPL");