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12#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
13
14#include <linux/delay.h>
15#include <linux/kernel.h>
16#include <linux/mman.h>
17#include <linux/mm.h>
18#include <linux/printk.h>
19#include <linux/slab.h>
20#include <linux/string.h>
21#include <linux/uaccess.h>
22#include <linux/module.h>
23#include <linux/kasan.h>
24
25
26
27
28
29
30static noinline void __init kmalloc_oob_right(void)
31{
32 char *ptr;
33 size_t size = 123;
34
35 pr_info("out-of-bounds to right\n");
36 ptr = kmalloc(size, GFP_KERNEL);
37 if (!ptr) {
38 pr_err("Allocation failed\n");
39 return;
40 }
41
42 ptr[size] = 'x';
43 kfree(ptr);
44}
45
46static noinline void __init kmalloc_oob_left(void)
47{
48 char *ptr;
49 size_t size = 15;
50
51 pr_info("out-of-bounds to left\n");
52 ptr = kmalloc(size, GFP_KERNEL);
53 if (!ptr) {
54 pr_err("Allocation failed\n");
55 return;
56 }
57
58 *ptr = *(ptr - 1);
59 kfree(ptr);
60}
61
62static noinline void __init kmalloc_node_oob_right(void)
63{
64 char *ptr;
65 size_t size = 4096;
66
67 pr_info("kmalloc_node(): out-of-bounds to right\n");
68 ptr = kmalloc_node(size, GFP_KERNEL, 0);
69 if (!ptr) {
70 pr_err("Allocation failed\n");
71 return;
72 }
73
74 ptr[size] = 0;
75 kfree(ptr);
76}
77
78#ifdef CONFIG_SLUB
79static noinline void __init kmalloc_pagealloc_oob_right(void)
80{
81 char *ptr;
82 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
83
84
85
86
87 pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
88 ptr = kmalloc(size, GFP_KERNEL);
89 if (!ptr) {
90 pr_err("Allocation failed\n");
91 return;
92 }
93
94 ptr[size] = 0;
95 kfree(ptr);
96}
97#endif
98
99static noinline void __init kmalloc_large_oob_right(void)
100{
101 char *ptr;
102 size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
103
104
105
106 pr_info("kmalloc large allocation: out-of-bounds to right\n");
107 ptr = kmalloc(size, GFP_KERNEL);
108 if (!ptr) {
109 pr_err("Allocation failed\n");
110 return;
111 }
112
113 ptr[size] = 0;
114 kfree(ptr);
115}
116
117static noinline void __init kmalloc_oob_krealloc_more(void)
118{
119 char *ptr1, *ptr2;
120 size_t size1 = 17;
121 size_t size2 = 19;
122
123 pr_info("out-of-bounds after krealloc more\n");
124 ptr1 = kmalloc(size1, GFP_KERNEL);
125 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
126 if (!ptr1 || !ptr2) {
127 pr_err("Allocation failed\n");
128 kfree(ptr1);
129 return;
130 }
131
132 ptr2[size2] = 'x';
133 kfree(ptr2);
134}
135
136static noinline void __init kmalloc_oob_krealloc_less(void)
137{
138 char *ptr1, *ptr2;
139 size_t size1 = 17;
140 size_t size2 = 15;
141
142 pr_info("out-of-bounds after krealloc less\n");
143 ptr1 = kmalloc(size1, GFP_KERNEL);
144 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
145 if (!ptr1 || !ptr2) {
146 pr_err("Allocation failed\n");
147 kfree(ptr1);
148 return;
149 }
150 ptr2[size2] = 'x';
151 kfree(ptr2);
152}
153
154static noinline void __init kmalloc_oob_16(void)
155{
156 struct {
157 u64 words[2];
158 } *ptr1, *ptr2;
159
160 pr_info("kmalloc out-of-bounds for 16-bytes access\n");
161 ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
162 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
163 if (!ptr1 || !ptr2) {
164 pr_err("Allocation failed\n");
165 kfree(ptr1);
166 kfree(ptr2);
167 return;
168 }
169 *ptr1 = *ptr2;
170 kfree(ptr1);
171 kfree(ptr2);
172}
173
174static noinline void __init kmalloc_oob_memset_2(void)
175{
176 char *ptr;
177 size_t size = 8;
178
179 pr_info("out-of-bounds in memset2\n");
180 ptr = kmalloc(size, GFP_KERNEL);
181 if (!ptr) {
182 pr_err("Allocation failed\n");
183 return;
184 }
185
186 memset(ptr+7, 0, 2);
187 kfree(ptr);
188}
189
190static noinline void __init kmalloc_oob_memset_4(void)
191{
192 char *ptr;
193 size_t size = 8;
194
195 pr_info("out-of-bounds in memset4\n");
196 ptr = kmalloc(size, GFP_KERNEL);
197 if (!ptr) {
198 pr_err("Allocation failed\n");
199 return;
200 }
201
202 memset(ptr+5, 0, 4);
203 kfree(ptr);
204}
205
206
207static noinline void __init kmalloc_oob_memset_8(void)
208{
209 char *ptr;
210 size_t size = 8;
211
212 pr_info("out-of-bounds in memset8\n");
213 ptr = kmalloc(size, GFP_KERNEL);
214 if (!ptr) {
215 pr_err("Allocation failed\n");
216 return;
217 }
218
219 memset(ptr+1, 0, 8);
220 kfree(ptr);
221}
222
223static noinline void __init kmalloc_oob_memset_16(void)
224{
225 char *ptr;
226 size_t size = 16;
227
228 pr_info("out-of-bounds in memset16\n");
229 ptr = kmalloc(size, GFP_KERNEL);
230 if (!ptr) {
231 pr_err("Allocation failed\n");
232 return;
233 }
234
235 memset(ptr+1, 0, 16);
236 kfree(ptr);
237}
238
239static noinline void __init kmalloc_oob_in_memset(void)
240{
241 char *ptr;
242 size_t size = 666;
243
244 pr_info("out-of-bounds in memset\n");
245 ptr = kmalloc(size, GFP_KERNEL);
246 if (!ptr) {
247 pr_err("Allocation failed\n");
248 return;
249 }
250
251 memset(ptr, 0, size+5);
252 kfree(ptr);
253}
254
255static noinline void __init kmalloc_uaf(void)
256{
257 char *ptr;
258 size_t size = 10;
259
260 pr_info("use-after-free\n");
261 ptr = kmalloc(size, GFP_KERNEL);
262 if (!ptr) {
263 pr_err("Allocation failed\n");
264 return;
265 }
266
267 kfree(ptr);
268 *(ptr + 8) = 'x';
269}
270
271static noinline void __init kmalloc_uaf_memset(void)
272{
273 char *ptr;
274 size_t size = 33;
275
276 pr_info("use-after-free in memset\n");
277 ptr = kmalloc(size, GFP_KERNEL);
278 if (!ptr) {
279 pr_err("Allocation failed\n");
280 return;
281 }
282
283 kfree(ptr);
284 memset(ptr, 0, size);
285}
286
287static noinline void __init kmalloc_uaf2(void)
288{
289 char *ptr1, *ptr2;
290 size_t size = 43;
291
292 pr_info("use-after-free after another kmalloc\n");
293 ptr1 = kmalloc(size, GFP_KERNEL);
294 if (!ptr1) {
295 pr_err("Allocation failed\n");
296 return;
297 }
298
299 kfree(ptr1);
300 ptr2 = kmalloc(size, GFP_KERNEL);
301 if (!ptr2) {
302 pr_err("Allocation failed\n");
303 return;
304 }
305
306 ptr1[40] = 'x';
307 if (ptr1 == ptr2)
308 pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
309 kfree(ptr2);
310}
311
312static noinline void __init kmem_cache_oob(void)
313{
314 char *p;
315 size_t size = 200;
316 struct kmem_cache *cache = kmem_cache_create("test_cache",
317 size, 0,
318 0, NULL);
319 if (!cache) {
320 pr_err("Cache allocation failed\n");
321 return;
322 }
323 pr_info("out-of-bounds in kmem_cache_alloc\n");
324 p = kmem_cache_alloc(cache, GFP_KERNEL);
325 if (!p) {
326 pr_err("Allocation failed\n");
327 kmem_cache_destroy(cache);
328 return;
329 }
330
331 *p = p[size];
332 kmem_cache_free(cache, p);
333 kmem_cache_destroy(cache);
334}
335
336static noinline void __init memcg_accounted_kmem_cache(void)
337{
338 int i;
339 char *p;
340 size_t size = 200;
341 struct kmem_cache *cache;
342
343 cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
344 if (!cache) {
345 pr_err("Cache allocation failed\n");
346 return;
347 }
348
349 pr_info("allocate memcg accounted object\n");
350
351
352
353
354 for (i = 0; i < 5; i++) {
355 p = kmem_cache_alloc(cache, GFP_KERNEL);
356 if (!p) {
357 pr_err("Allocation failed\n");
358 goto free_cache;
359 }
360 kmem_cache_free(cache, p);
361 msleep(100);
362 }
363
364free_cache:
365 kmem_cache_destroy(cache);
366}
367
368static char global_array[10];
369
370static noinline void __init kasan_global_oob(void)
371{
372 volatile int i = 3;
373 char *p = &global_array[ARRAY_SIZE(global_array) + i];
374
375 pr_info("out-of-bounds global variable\n");
376 *(volatile char *)p;
377}
378
379static noinline void __init kasan_stack_oob(void)
380{
381 char stack_array[10];
382 volatile int i = 0;
383 char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
384
385 pr_info("out-of-bounds on stack\n");
386 *(volatile char *)p;
387}
388
389static noinline void __init ksize_unpoisons_memory(void)
390{
391 char *ptr;
392 size_t size = 123, real_size = size;
393
394 pr_info("ksize() unpoisons the whole allocated chunk\n");
395 ptr = kmalloc(size, GFP_KERNEL);
396 if (!ptr) {
397 pr_err("Allocation failed\n");
398 return;
399 }
400 real_size = ksize(ptr);
401
402 ptr[size] = 'x';
403
404 ptr[real_size] = 'y';
405 kfree(ptr);
406}
407
408static noinline void __init copy_user_test(void)
409{
410 char *kmem;
411 char __user *usermem;
412 size_t size = 10;
413 int unused;
414
415 kmem = kmalloc(size, GFP_KERNEL);
416 if (!kmem)
417 return;
418
419 usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
420 PROT_READ | PROT_WRITE | PROT_EXEC,
421 MAP_ANONYMOUS | MAP_PRIVATE, 0);
422 if (IS_ERR(usermem)) {
423 pr_err("Failed to allocate user memory\n");
424 kfree(kmem);
425 return;
426 }
427
428 pr_info("out-of-bounds in copy_from_user()\n");
429 unused = copy_from_user(kmem, usermem, size + 1);
430
431 pr_info("out-of-bounds in copy_to_user()\n");
432 unused = copy_to_user(usermem, kmem, size + 1);
433
434 pr_info("out-of-bounds in __copy_from_user()\n");
435 unused = __copy_from_user(kmem, usermem, size + 1);
436
437 pr_info("out-of-bounds in __copy_to_user()\n");
438 unused = __copy_to_user(usermem, kmem, size + 1);
439
440 pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
441 unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
442
443 pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
444 unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
445
446 pr_info("out-of-bounds in strncpy_from_user()\n");
447 unused = strncpy_from_user(kmem, usermem, size + 1);
448
449 vm_munmap((unsigned long)usermem, PAGE_SIZE);
450 kfree(kmem);
451}
452
453static noinline void __init use_after_scope_test(void)
454{
455 volatile char *volatile p;
456
457 pr_info("use-after-scope on int\n");
458 {
459 int local = 0;
460
461 p = (char *)&local;
462 }
463 p[0] = 1;
464 p[3] = 1;
465
466 pr_info("use-after-scope on array\n");
467 {
468 char local[1024] = {0};
469
470 p = local;
471 }
472 p[0] = 1;
473 p[1023] = 1;
474}
475
476static int __init kmalloc_tests_init(void)
477{
478
479
480
481
482 bool multishot = kasan_save_enable_multi_shot();
483
484 kmalloc_oob_right();
485 kmalloc_oob_left();
486 kmalloc_node_oob_right();
487#ifdef CONFIG_SLUB
488 kmalloc_pagealloc_oob_right();
489#endif
490 kmalloc_large_oob_right();
491 kmalloc_oob_krealloc_more();
492 kmalloc_oob_krealloc_less();
493 kmalloc_oob_16();
494 kmalloc_oob_in_memset();
495 kmalloc_oob_memset_2();
496 kmalloc_oob_memset_4();
497 kmalloc_oob_memset_8();
498 kmalloc_oob_memset_16();
499 kmalloc_uaf();
500 kmalloc_uaf_memset();
501 kmalloc_uaf2();
502 kmem_cache_oob();
503 memcg_accounted_kmem_cache();
504 kasan_stack_oob();
505 kasan_global_oob();
506 ksize_unpoisons_memory();
507 copy_user_test();
508 use_after_scope_test();
509
510 kasan_restore_multi_shot(multishot);
511
512 return -EAGAIN;
513}
514
515module_init(kmalloc_tests_init);
516MODULE_LICENSE("GPL");
517
