1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 *
4 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
5 * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
6 */
7
8 #include <linux/bitops.h>
9 #include <linux/delay.h>
10 #include <linux/kasan.h>
11 #include <linux/kernel.h>
12 #include <linux/mm.h>
13 #include <linux/mman.h>
14 #include <linux/module.h>
15 #include <linux/printk.h>
16 #include <linux/random.h>
17 #include <linux/slab.h>
18 #include <linux/string.h>
19 #include <linux/uaccess.h>
20 #include <linux/io.h>
21 #include <linux/vmalloc.h>
22 #include <linux/set_memory.h>
23
24 #include <asm/page.h>
25
26 #include <kunit/test.h>
27
28 #include "../mm/kasan/kasan.h"
29
30 #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
31
32 /*
33 * Some tests use these global variables to store return values from function
34 * calls that could otherwise be eliminated by the compiler as dead code.
35 */
36 void *kasan_ptr_result;
37 int kasan_int_result;
38
39 static struct kunit_resource resource;
40 static struct kunit_kasan_status test_status;
41 static bool multishot;
42
43 /*
44 * Temporarily enable multi-shot mode. Otherwise, KASAN would only report the
45 * first detected bug and panic the kernel if panic_on_warn is enabled. For
46 * hardware tag-based KASAN also allow tag checking to be reenabled for each
47 * test, see the comment for KUNIT_EXPECT_KASAN_FAIL().
48 */
kasan_test_init(struct kunit * test)49 static int kasan_test_init(struct kunit *test)
50 {
51 if (!kasan_enabled()) {
52 kunit_err(test, "can't run KASAN tests with KASAN disabled");
53 return -1;
54 }
55
56 multishot = kasan_save_enable_multi_shot();
57 test_status.report_found = false;
58 test_status.sync_fault = false;
59 kunit_add_named_resource(test, NULL, NULL, &resource,
60 "kasan_status", &test_status);
61 return 0;
62 }
63
kasan_test_exit(struct kunit * test)64 static void kasan_test_exit(struct kunit *test)
65 {
66 kasan_restore_multi_shot(multishot);
67 KUNIT_EXPECT_FALSE(test, test_status.report_found);
68 }
69
70 /**
71 * KUNIT_EXPECT_KASAN_FAIL() - check that the executed expression produces a
72 * KASAN report; causes a test failure otherwise. This relies on a KUnit
73 * resource named "kasan_status". Do not use this name for KUnit resources
74 * outside of KASAN tests.
75 *
76 * For hardware tag-based KASAN, when a synchronous tag fault happens, tag
77 * checking is auto-disabled. When this happens, this test handler reenables
78 * tag checking. As tag checking can be only disabled or enabled per CPU,
79 * this handler disables migration (preemption).
80 *
81 * Since the compiler doesn't see that the expression can change the test_status
82 * fields, it can reorder or optimize away the accesses to those fields.
83 * Use READ/WRITE_ONCE() for the accesses and compiler barriers around the
84 * expression to prevent that.
85 *
86 * In between KUNIT_EXPECT_KASAN_FAIL checks, test_status.report_found is kept
87 * as false. This allows detecting KASAN reports that happen outside of the
88 * checks by asserting !test_status.report_found at the start of
89 * KUNIT_EXPECT_KASAN_FAIL and in kasan_test_exit.
90 */
91 #define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \
92 if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && \
93 kasan_sync_fault_possible()) \
94 migrate_disable(); \
95 KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found)); \
96 barrier(); \
97 expression; \
98 barrier(); \
99 if (kasan_async_fault_possible()) \
100 kasan_force_async_fault(); \
101 if (!READ_ONCE(test_status.report_found)) { \
102 KUNIT_FAIL(test, KUNIT_SUBTEST_INDENT "KASAN failure " \
103 "expected in \"" #expression \
104 "\", but none occurred"); \
105 } \
106 if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && \
107 kasan_sync_fault_possible()) { \
108 if (READ_ONCE(test_status.report_found) && \
109 READ_ONCE(test_status.sync_fault)) \
110 kasan_enable_tagging(); \
111 migrate_enable(); \
112 } \
113 WRITE_ONCE(test_status.report_found, false); \
114 } while (0)
115
116 #define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do { \
117 if (!IS_ENABLED(config)) { \
118 kunit_info((test), "skipping, " #config " required"); \
119 return; \
120 } \
121 } while (0)
122
123 #define KASAN_TEST_NEEDS_CONFIG_OFF(test, config) do { \
124 if (IS_ENABLED(config)) { \
125 kunit_info((test), "skipping, " #config " enabled"); \
126 return; \
127 } \
128 } while (0)
129
kmalloc_oob_right(struct kunit * test)130 static void kmalloc_oob_right(struct kunit *test)
131 {
132 char *ptr;
133 size_t size = 128 - KASAN_GRANULE_SIZE - 5;
134
135 ptr = kmalloc(size, GFP_KERNEL);
136 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
137
138 /*
139 * An unaligned access past the requested kmalloc size.
140 * Only generic KASAN can precisely detect these.
141 */
142 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
143 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x');
144
145 /*
146 * An aligned access into the first out-of-bounds granule that falls
147 * within the aligned kmalloc object.
148 */
149 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + 5] = 'y');
150
151 /* Out-of-bounds access past the aligned kmalloc object. */
152 KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] =
153 ptr[size + KASAN_GRANULE_SIZE + 5]);
154
155 kfree(ptr);
156 }
157
kmalloc_oob_left(struct kunit * test)158 static void kmalloc_oob_left(struct kunit *test)
159 {
160 char *ptr;
161 size_t size = 15;
162
163 ptr = kmalloc(size, GFP_KERNEL);
164 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
165
166 KUNIT_EXPECT_KASAN_FAIL(test, *ptr = *(ptr - 1));
167 kfree(ptr);
168 }
169
kmalloc_node_oob_right(struct kunit * test)170 static void kmalloc_node_oob_right(struct kunit *test)
171 {
172 char *ptr;
173 size_t size = 4096;
174
175 ptr = kmalloc_node(size, GFP_KERNEL, 0);
176 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
177
178 KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
179 kfree(ptr);
180 }
181
182 /*
183 * These kmalloc_pagealloc_* tests try allocating a memory chunk that doesn't
184 * fit into a slab cache and therefore is allocated via the page allocator
185 * fallback. Since this kind of fallback is only implemented for SLUB, these
186 * tests are limited to that allocator.
187 */
kmalloc_pagealloc_oob_right(struct kunit * test)188 static void kmalloc_pagealloc_oob_right(struct kunit *test)
189 {
190 char *ptr;
191 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
192
193 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
194
195 ptr = kmalloc(size, GFP_KERNEL);
196 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
197
198 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0);
199
200 kfree(ptr);
201 }
202
kmalloc_pagealloc_uaf(struct kunit * test)203 static void kmalloc_pagealloc_uaf(struct kunit *test)
204 {
205 char *ptr;
206 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
207
208 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
209
210 ptr = kmalloc(size, GFP_KERNEL);
211 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
212 kfree(ptr);
213
214 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
215 }
216
kmalloc_pagealloc_invalid_free(struct kunit * test)217 static void kmalloc_pagealloc_invalid_free(struct kunit *test)
218 {
219 char *ptr;
220 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
221
222 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
223
224 ptr = kmalloc(size, GFP_KERNEL);
225 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
226
227 KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
228 }
229
pagealloc_oob_right(struct kunit * test)230 static void pagealloc_oob_right(struct kunit *test)
231 {
232 char *ptr;
233 struct page *pages;
234 size_t order = 4;
235 size_t size = (1UL << (PAGE_SHIFT + order));
236
237 /*
238 * With generic KASAN page allocations have no redzones, thus
239 * out-of-bounds detection is not guaranteed.
240 * See https://bugzilla.kernel.org/show_bug.cgi?id=210503.
241 */
242 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
243
244 pages = alloc_pages(GFP_KERNEL, order);
245 ptr = page_address(pages);
246 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
247
248 KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
249 free_pages((unsigned long)ptr, order);
250 }
251
pagealloc_uaf(struct kunit * test)252 static void pagealloc_uaf(struct kunit *test)
253 {
254 char *ptr;
255 struct page *pages;
256 size_t order = 4;
257
258 pages = alloc_pages(GFP_KERNEL, order);
259 ptr = page_address(pages);
260 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
261 free_pages((unsigned long)ptr, order);
262
263 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
264 }
265
kmalloc_large_oob_right(struct kunit * test)266 static void kmalloc_large_oob_right(struct kunit *test)
267 {
268 char *ptr;
269 size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
270
271 /*
272 * Allocate a chunk that is large enough, but still fits into a slab
273 * and does not trigger the page allocator fallback in SLUB.
274 */
275 ptr = kmalloc(size, GFP_KERNEL);
276 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
277
278 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
279 kfree(ptr);
280 }
281
krealloc_more_oob_helper(struct kunit * test,size_t size1,size_t size2)282 static void krealloc_more_oob_helper(struct kunit *test,
283 size_t size1, size_t size2)
284 {
285 char *ptr1, *ptr2;
286 size_t middle;
287
288 KUNIT_ASSERT_LT(test, size1, size2);
289 middle = size1 + (size2 - size1) / 2;
290
291 ptr1 = kmalloc(size1, GFP_KERNEL);
292 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
293
294 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
295 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
296
297 /* All offsets up to size2 must be accessible. */
298 ptr2[size1 - 1] = 'x';
299 ptr2[size1] = 'x';
300 ptr2[middle] = 'x';
301 ptr2[size2 - 1] = 'x';
302
303 /* Generic mode is precise, so unaligned size2 must be inaccessible. */
304 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
305 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
306
307 /* For all modes first aligned offset after size2 must be inaccessible. */
308 KUNIT_EXPECT_KASAN_FAIL(test,
309 ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x');
310
311 kfree(ptr2);
312 }
313
krealloc_less_oob_helper(struct kunit * test,size_t size1,size_t size2)314 static void krealloc_less_oob_helper(struct kunit *test,
315 size_t size1, size_t size2)
316 {
317 char *ptr1, *ptr2;
318 size_t middle;
319
320 KUNIT_ASSERT_LT(test, size2, size1);
321 middle = size2 + (size1 - size2) / 2;
322
323 ptr1 = kmalloc(size1, GFP_KERNEL);
324 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
325
326 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
327 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
328
329 /* Must be accessible for all modes. */
330 ptr2[size2 - 1] = 'x';
331
332 /* Generic mode is precise, so unaligned size2 must be inaccessible. */
333 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
334 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
335
336 /* For all modes first aligned offset after size2 must be inaccessible. */
337 KUNIT_EXPECT_KASAN_FAIL(test,
338 ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x');
339
340 /*
341 * For all modes all size2, middle, and size1 should land in separate
342 * granules and thus the latter two offsets should be inaccessible.
343 */
344 KUNIT_EXPECT_LE(test, round_up(size2, KASAN_GRANULE_SIZE),
345 round_down(middle, KASAN_GRANULE_SIZE));
346 KUNIT_EXPECT_LE(test, round_up(middle, KASAN_GRANULE_SIZE),
347 round_down(size1, KASAN_GRANULE_SIZE));
348 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[middle] = 'x');
349 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1 - 1] = 'x');
350 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1] = 'x');
351
352 kfree(ptr2);
353 }
354
krealloc_more_oob(struct kunit * test)355 static void krealloc_more_oob(struct kunit *test)
356 {
357 krealloc_more_oob_helper(test, 201, 235);
358 }
359
krealloc_less_oob(struct kunit * test)360 static void krealloc_less_oob(struct kunit *test)
361 {
362 krealloc_less_oob_helper(test, 235, 201);
363 }
364
krealloc_pagealloc_more_oob(struct kunit * test)365 static void krealloc_pagealloc_more_oob(struct kunit *test)
366 {
367 /* page_alloc fallback in only implemented for SLUB. */
368 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
369
370 krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201,
371 KMALLOC_MAX_CACHE_SIZE + 235);
372 }
373
krealloc_pagealloc_less_oob(struct kunit * test)374 static void krealloc_pagealloc_less_oob(struct kunit *test)
375 {
376 /* page_alloc fallback in only implemented for SLUB. */
377 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
378
379 krealloc_less_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 235,
380 KMALLOC_MAX_CACHE_SIZE + 201);
381 }
382
383 /*
384 * Check that krealloc() detects a use-after-free, returns NULL,
385 * and doesn't unpoison the freed object.
386 */
krealloc_uaf(struct kunit * test)387 static void krealloc_uaf(struct kunit *test)
388 {
389 char *ptr1, *ptr2;
390 int size1 = 201;
391 int size2 = 235;
392
393 ptr1 = kmalloc(size1, GFP_KERNEL);
394 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
395 kfree(ptr1);
396
397 KUNIT_EXPECT_KASAN_FAIL(test, ptr2 = krealloc(ptr1, size2, GFP_KERNEL));
398 KUNIT_ASSERT_PTR_EQ(test, (void *)ptr2, NULL);
399 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)ptr1);
400 }
401
kmalloc_oob_16(struct kunit * test)402 static void kmalloc_oob_16(struct kunit *test)
403 {
404 struct {
405 u64 words[2];
406 } *ptr1, *ptr2;
407
408 /* This test is specifically crafted for the generic mode. */
409 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
410
411 ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
412 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
413
414 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
415 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
416
417 KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
418 kfree(ptr1);
419 kfree(ptr2);
420 }
421
kmalloc_uaf_16(struct kunit * test)422 static void kmalloc_uaf_16(struct kunit *test)
423 {
424 struct {
425 u64 words[2];
426 } *ptr1, *ptr2;
427
428 ptr1 = kmalloc(sizeof(*ptr1), GFP_KERNEL);
429 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
430
431 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
432 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
433 kfree(ptr2);
434
435 KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
436 kfree(ptr1);
437 }
438
439 /*
440 * Note: in the memset tests below, the written range touches both valid and
441 * invalid memory. This makes sure that the instrumentation does not only check
442 * the starting address but the whole range.
443 */
444
kmalloc_oob_memset_2(struct kunit * test)445 static void kmalloc_oob_memset_2(struct kunit *test)
446 {
447 char *ptr;
448 size_t size = 128 - KASAN_GRANULE_SIZE;
449
450 ptr = kmalloc(size, GFP_KERNEL);
451 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
452
453 OPTIMIZER_HIDE_VAR(size);
454 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, 2));
455 kfree(ptr);
456 }
457
kmalloc_oob_memset_4(struct kunit * test)458 static void kmalloc_oob_memset_4(struct kunit *test)
459 {
460 char *ptr;
461 size_t size = 128 - KASAN_GRANULE_SIZE;
462
463 ptr = kmalloc(size, GFP_KERNEL);
464 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
465
466 OPTIMIZER_HIDE_VAR(size);
467 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, 4));
468 kfree(ptr);
469 }
470
kmalloc_oob_memset_8(struct kunit * test)471 static void kmalloc_oob_memset_8(struct kunit *test)
472 {
473 char *ptr;
474 size_t size = 128 - KASAN_GRANULE_SIZE;
475
476 ptr = kmalloc(size, GFP_KERNEL);
477 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
478
479 OPTIMIZER_HIDE_VAR(size);
480 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, 8));
481 kfree(ptr);
482 }
483
kmalloc_oob_memset_16(struct kunit * test)484 static void kmalloc_oob_memset_16(struct kunit *test)
485 {
486 char *ptr;
487 size_t size = 128 - KASAN_GRANULE_SIZE;
488
489 ptr = kmalloc(size, GFP_KERNEL);
490 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
491
492 OPTIMIZER_HIDE_VAR(size);
493 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, 16));
494 kfree(ptr);
495 }
496
kmalloc_oob_in_memset(struct kunit * test)497 static void kmalloc_oob_in_memset(struct kunit *test)
498 {
499 char *ptr;
500 size_t size = 128 - KASAN_GRANULE_SIZE;
501
502 ptr = kmalloc(size, GFP_KERNEL);
503 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
504
505 OPTIMIZER_HIDE_VAR(ptr);
506 OPTIMIZER_HIDE_VAR(size);
507 KUNIT_EXPECT_KASAN_FAIL(test,
508 memset(ptr, 0, size + KASAN_GRANULE_SIZE));
509 kfree(ptr);
510 }
511
kmalloc_memmove_negative_size(struct kunit * test)512 static void kmalloc_memmove_negative_size(struct kunit *test)
513 {
514 char *ptr;
515 size_t size = 64;
516 size_t invalid_size = -2;
517
518 /*
519 * Hardware tag-based mode doesn't check memmove for negative size.
520 * As a result, this test introduces a side-effect memory corruption,
521 * which can result in a crash.
522 */
523 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);
524
525 ptr = kmalloc(size, GFP_KERNEL);
526 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
527
528 memset((char *)ptr, 0, 64);
529 OPTIMIZER_HIDE_VAR(ptr);
530 OPTIMIZER_HIDE_VAR(invalid_size);
531 KUNIT_EXPECT_KASAN_FAIL(test,
532 memmove((char *)ptr, (char *)ptr + 4, invalid_size));
533 kfree(ptr);
534 }
535
kmalloc_memmove_invalid_size(struct kunit * test)536 static void kmalloc_memmove_invalid_size(struct kunit *test)
537 {
538 char *ptr;
539 size_t size = 64;
540 volatile size_t invalid_size = size;
541
542 ptr = kmalloc(size, GFP_KERNEL);
543 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
544
545 memset((char *)ptr, 0, 64);
546 OPTIMIZER_HIDE_VAR(ptr);
547 KUNIT_EXPECT_KASAN_FAIL(test,
548 memmove((char *)ptr, (char *)ptr + 4, invalid_size));
549 kfree(ptr);
550 }
551
kmalloc_uaf(struct kunit * test)552 static void kmalloc_uaf(struct kunit *test)
553 {
554 char *ptr;
555 size_t size = 10;
556
557 ptr = kmalloc(size, GFP_KERNEL);
558 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
559
560 kfree(ptr);
561 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[8]);
562 }
563
kmalloc_uaf_memset(struct kunit * test)564 static void kmalloc_uaf_memset(struct kunit *test)
565 {
566 char *ptr;
567 size_t size = 33;
568
569 /*
570 * Only generic KASAN uses quarantine, which is required to avoid a
571 * kernel memory corruption this test causes.
572 */
573 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
574
575 ptr = kmalloc(size, GFP_KERNEL);
576 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
577
578 kfree(ptr);
579 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size));
580 }
581
kmalloc_uaf2(struct kunit * test)582 static void kmalloc_uaf2(struct kunit *test)
583 {
584 char *ptr1, *ptr2;
585 size_t size = 43;
586 int counter = 0;
587
588 again:
589 ptr1 = kmalloc(size, GFP_KERNEL);
590 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
591
592 kfree(ptr1);
593
594 ptr2 = kmalloc(size, GFP_KERNEL);
595 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
596
597 /*
598 * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same.
599 * Allow up to 16 attempts at generating different tags.
600 */
601 if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 16) {
602 kfree(ptr2);
603 goto again;
604 }
605
606 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[40]);
607 KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
608
609 kfree(ptr2);
610 }
611
kfree_via_page(struct kunit * test)612 static void kfree_via_page(struct kunit *test)
613 {
614 char *ptr;
615 size_t size = 8;
616 struct page *page;
617 unsigned long offset;
618
619 ptr = kmalloc(size, GFP_KERNEL);
620 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
621
622 page = virt_to_page(ptr);
623 offset = offset_in_page(ptr);
624 kfree(page_address(page) + offset);
625 }
626
kfree_via_phys(struct kunit * test)627 static void kfree_via_phys(struct kunit *test)
628 {
629 char *ptr;
630 size_t size = 8;
631 phys_addr_t phys;
632
633 ptr = kmalloc(size, GFP_KERNEL);
634 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
635
636 phys = virt_to_phys(ptr);
637 kfree(phys_to_virt(phys));
638 }
639
kmem_cache_oob(struct kunit * test)640 static void kmem_cache_oob(struct kunit *test)
641 {
642 char *p;
643 size_t size = 200;
644 struct kmem_cache *cache;
645
646 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
647 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
648
649 p = kmem_cache_alloc(cache, GFP_KERNEL);
650 if (!p) {
651 kunit_err(test, "Allocation failed: %s\n", __func__);
652 kmem_cache_destroy(cache);
653 return;
654 }
655
656 KUNIT_EXPECT_KASAN_FAIL(test, *p = p[size + OOB_TAG_OFF]);
657
658 kmem_cache_free(cache, p);
659 kmem_cache_destroy(cache);
660 }
661
kmem_cache_accounted(struct kunit * test)662 static void kmem_cache_accounted(struct kunit *test)
663 {
664 int i;
665 char *p;
666 size_t size = 200;
667 struct kmem_cache *cache;
668
669 cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
670 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
671
672 /*
673 * Several allocations with a delay to allow for lazy per memcg kmem
674 * cache creation.
675 */
676 for (i = 0; i < 5; i++) {
677 p = kmem_cache_alloc(cache, GFP_KERNEL);
678 if (!p)
679 goto free_cache;
680
681 kmem_cache_free(cache, p);
682 msleep(100);
683 }
684
685 free_cache:
686 kmem_cache_destroy(cache);
687 }
688
kmem_cache_bulk(struct kunit * test)689 static void kmem_cache_bulk(struct kunit *test)
690 {
691 struct kmem_cache *cache;
692 size_t size = 200;
693 char *p[10];
694 bool ret;
695 int i;
696
697 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
698 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
699
700 ret = kmem_cache_alloc_bulk(cache, GFP_KERNEL, ARRAY_SIZE(p), (void **)&p);
701 if (!ret) {
702 kunit_err(test, "Allocation failed: %s\n", __func__);
703 kmem_cache_destroy(cache);
704 return;
705 }
706
707 for (i = 0; i < ARRAY_SIZE(p); i++)
708 p[i][0] = p[i][size - 1] = 42;
709
710 kmem_cache_free_bulk(cache, ARRAY_SIZE(p), (void **)&p);
711 kmem_cache_destroy(cache);
712 }
713
714 static char global_array[10];
715
kasan_global_oob_right(struct kunit * test)716 static void kasan_global_oob_right(struct kunit *test)
717 {
718 /*
719 * Deliberate out-of-bounds access. To prevent CONFIG_UBSAN_LOCAL_BOUNDS
720 * from failing here and panicing the kernel, access the array via a
721 * volatile pointer, which will prevent the compiler from being able to
722 * determine the array bounds.
723 *
724 * This access uses a volatile pointer to char (char *volatile) rather
725 * than the more conventional pointer to volatile char (volatile char *)
726 * because we want to prevent the compiler from making inferences about
727 * the pointer itself (i.e. its array bounds), not the data that it
728 * refers to.
729 */
730 char *volatile array = global_array;
731 char *p = &array[ARRAY_SIZE(global_array) + 3];
732
733 /* Only generic mode instruments globals. */
734 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
735
736 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
737 }
738
kasan_global_oob_left(struct kunit * test)739 static void kasan_global_oob_left(struct kunit *test)
740 {
741 char *volatile array = global_array;
742 char *p = array - 3;
743
744 /*
745 * GCC is known to fail this test, skip it.
746 * See https://bugzilla.kernel.org/show_bug.cgi?id=215051.
747 */
748 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_CC_IS_CLANG);
749 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
750 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
751 }
752
753 /* Check that ksize() makes the whole object accessible. */
ksize_unpoisons_memory(struct kunit * test)754 static void ksize_unpoisons_memory(struct kunit *test)
755 {
756 char *ptr;
757 size_t size = 123, real_size;
758
759 ptr = kmalloc(size, GFP_KERNEL);
760 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
761 real_size = ksize(ptr);
762
763 /* This access shouldn't trigger a KASAN report. */
764 ptr[size] = 'x';
765
766 /* This one must. */
767 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size]);
768
769 kfree(ptr);
770 }
771
772 /*
773 * Check that a use-after-free is detected by ksize() and via normal accesses
774 * after it.
775 */
ksize_uaf(struct kunit * test)776 static void ksize_uaf(struct kunit *test)
777 {
778 char *ptr;
779 int size = 128 - KASAN_GRANULE_SIZE;
780
781 ptr = kmalloc(size, GFP_KERNEL);
782 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
783 kfree(ptr);
784
785 KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
786 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
787 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
788 }
789
kasan_stack_oob(struct kunit * test)790 static void kasan_stack_oob(struct kunit *test)
791 {
792 char stack_array[10];
793 /* See comment in kasan_global_oob. */
794 char *volatile array = stack_array;
795 char *p = &array[ARRAY_SIZE(stack_array) + OOB_TAG_OFF];
796
797 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
798
799 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
800 }
801
kasan_alloca_oob_left(struct kunit * test)802 static void kasan_alloca_oob_left(struct kunit *test)
803 {
804 volatile int i = 10;
805 char alloca_array[i];
806 /* See comment in kasan_global_oob. */
807 char *volatile array = alloca_array;
808 char *p = array - 1;
809
810 /* Only generic mode instruments dynamic allocas. */
811 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
812 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
813
814 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
815 }
816
kasan_alloca_oob_right(struct kunit * test)817 static void kasan_alloca_oob_right(struct kunit *test)
818 {
819 volatile int i = 10;
820 char alloca_array[i];
821 /* See comment in kasan_global_oob. */
822 char *volatile array = alloca_array;
823 char *p = array + i;
824
825 /* Only generic mode instruments dynamic allocas. */
826 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
827 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
828
829 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
830 }
831
kmem_cache_double_free(struct kunit * test)832 static void kmem_cache_double_free(struct kunit *test)
833 {
834 char *p;
835 size_t size = 200;
836 struct kmem_cache *cache;
837
838 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
839 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
840
841 p = kmem_cache_alloc(cache, GFP_KERNEL);
842 if (!p) {
843 kunit_err(test, "Allocation failed: %s\n", __func__);
844 kmem_cache_destroy(cache);
845 return;
846 }
847
848 kmem_cache_free(cache, p);
849 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p));
850 kmem_cache_destroy(cache);
851 }
852
kmem_cache_invalid_free(struct kunit * test)853 static void kmem_cache_invalid_free(struct kunit *test)
854 {
855 char *p;
856 size_t size = 200;
857 struct kmem_cache *cache;
858
859 cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
860 NULL);
861 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
862
863 p = kmem_cache_alloc(cache, GFP_KERNEL);
864 if (!p) {
865 kunit_err(test, "Allocation failed: %s\n", __func__);
866 kmem_cache_destroy(cache);
867 return;
868 }
869
870 /* Trigger invalid free, the object doesn't get freed. */
871 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));
872
873 /*
874 * Properly free the object to prevent the "Objects remaining in
875 * test_cache on __kmem_cache_shutdown" BUG failure.
876 */
877 kmem_cache_free(cache, p);
878
879 kmem_cache_destroy(cache);
880 }
881
empty_cache_ctor(void * object)882 static void empty_cache_ctor(void *object) { }
883
kmem_cache_double_destroy(struct kunit * test)884 static void kmem_cache_double_destroy(struct kunit *test)
885 {
886 struct kmem_cache *cache;
887
888 /* Provide a constructor to prevent cache merging. */
889 cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor);
890 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
891 kmem_cache_destroy(cache);
892 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache));
893 }
894
kasan_memchr(struct kunit * test)895 static void kasan_memchr(struct kunit *test)
896 {
897 char *ptr;
898 size_t size = 24;
899
900 /*
901 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
902 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
903 */
904 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
905
906 if (OOB_TAG_OFF)
907 size = round_up(size, OOB_TAG_OFF);
908
909 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
910 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
911
912 OPTIMIZER_HIDE_VAR(ptr);
913 OPTIMIZER_HIDE_VAR(size);
914 KUNIT_EXPECT_KASAN_FAIL(test,
915 kasan_ptr_result = memchr(ptr, '1', size + 1));
916
917 kfree(ptr);
918 }
919
kasan_memcmp(struct kunit * test)920 static void kasan_memcmp(struct kunit *test)
921 {
922 char *ptr;
923 size_t size = 24;
924 int arr[9];
925
926 /*
927 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
928 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
929 */
930 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
931
932 if (OOB_TAG_OFF)
933 size = round_up(size, OOB_TAG_OFF);
934
935 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
936 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
937 memset(arr, 0, sizeof(arr));
938
939 OPTIMIZER_HIDE_VAR(ptr);
940 OPTIMIZER_HIDE_VAR(size);
941 KUNIT_EXPECT_KASAN_FAIL(test,
942 kasan_int_result = memcmp(ptr, arr, size+1));
943 kfree(ptr);
944 }
945
kasan_strings(struct kunit * test)946 static void kasan_strings(struct kunit *test)
947 {
948 char *ptr;
949 size_t size = 24;
950
951 /*
952 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
953 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
954 */
955 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
956
957 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
958 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
959
960 kfree(ptr);
961
962 /*
963 * Try to cause only 1 invalid access (less spam in dmesg).
964 * For that we need ptr to point to zeroed byte.
965 * Skip metadata that could be stored in freed object so ptr
966 * will likely point to zeroed byte.
967 */
968 ptr += 16;
969 KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strchr(ptr, '1'));
970
971 KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strrchr(ptr, '1'));
972
973 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strcmp(ptr, "2"));
974
975 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strncmp(ptr, "2", 1));
976
977 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strlen(ptr));
978
979 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strnlen(ptr, 1));
980 }
981
kasan_bitops_modify(struct kunit * test,int nr,void * addr)982 static void kasan_bitops_modify(struct kunit *test, int nr, void *addr)
983 {
984 KUNIT_EXPECT_KASAN_FAIL(test, set_bit(nr, addr));
985 KUNIT_EXPECT_KASAN_FAIL(test, __set_bit(nr, addr));
986 KUNIT_EXPECT_KASAN_FAIL(test, clear_bit(nr, addr));
987 KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit(nr, addr));
988 KUNIT_EXPECT_KASAN_FAIL(test, clear_bit_unlock(nr, addr));
989 KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit_unlock(nr, addr));
990 KUNIT_EXPECT_KASAN_FAIL(test, change_bit(nr, addr));
991 KUNIT_EXPECT_KASAN_FAIL(test, __change_bit(nr, addr));
992 }
993
kasan_bitops_test_and_modify(struct kunit * test,int nr,void * addr)994 static void kasan_bitops_test_and_modify(struct kunit *test, int nr, void *addr)
995 {
996 KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit(nr, addr));
997 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_set_bit(nr, addr));
998 KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit_lock(nr, addr));
999 KUNIT_EXPECT_KASAN_FAIL(test, test_and_clear_bit(nr, addr));
1000 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_clear_bit(nr, addr));
1001 KUNIT_EXPECT_KASAN_FAIL(test, test_and_change_bit(nr, addr));
1002 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_change_bit(nr, addr));
1003 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = test_bit(nr, addr));
1004
1005 #if defined(clear_bit_unlock_is_negative_byte)
1006 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result =
1007 clear_bit_unlock_is_negative_byte(nr, addr));
1008 #endif
1009 }
1010
kasan_bitops_generic(struct kunit * test)1011 static void kasan_bitops_generic(struct kunit *test)
1012 {
1013 long *bits;
1014
1015 /* This test is specifically crafted for the generic mode. */
1016 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
1017
1018 /*
1019 * Allocate 1 more byte, which causes kzalloc to round up to 16 bytes;
1020 * this way we do not actually corrupt other memory.
1021 */
1022 bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL);
1023 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
1024
1025 /*
1026 * Below calls try to access bit within allocated memory; however, the
1027 * below accesses are still out-of-bounds, since bitops are defined to
1028 * operate on the whole long the bit is in.
1029 */
1030 kasan_bitops_modify(test, BITS_PER_LONG, bits);
1031
1032 /*
1033 * Below calls try to access bit beyond allocated memory.
1034 */
1035 kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, bits);
1036
1037 kfree(bits);
1038 }
1039
kasan_bitops_tags(struct kunit * test)1040 static void kasan_bitops_tags(struct kunit *test)
1041 {
1042 long *bits;
1043
1044 /* This test is specifically crafted for tag-based modes. */
1045 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1046
1047 /* kmalloc-64 cache will be used and the last 16 bytes will be the redzone. */
1048 bits = kzalloc(48, GFP_KERNEL);
1049 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
1050
1051 /* Do the accesses past the 48 allocated bytes, but within the redone. */
1052 kasan_bitops_modify(test, BITS_PER_LONG, (void *)bits + 48);
1053 kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, (void *)bits + 48);
1054
1055 kfree(bits);
1056 }
1057
kmalloc_double_kzfree(struct kunit * test)1058 static void kmalloc_double_kzfree(struct kunit *test)
1059 {
1060 char *ptr;
1061 size_t size = 16;
1062
1063 ptr = kmalloc(size, GFP_KERNEL);
1064 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1065
1066 kfree_sensitive(ptr);
1067 KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr));
1068 }
1069
vmalloc_helpers_tags(struct kunit * test)1070 static void vmalloc_helpers_tags(struct kunit *test)
1071 {
1072 void *ptr;
1073
1074 /* This test is intended for tag-based modes. */
1075 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1076
1077 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1078
1079 ptr = vmalloc(PAGE_SIZE);
1080 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1081
1082 /* Check that the returned pointer is tagged. */
1083 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1084 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1085
1086 /* Make sure exported vmalloc helpers handle tagged pointers. */
1087 KUNIT_ASSERT_TRUE(test, is_vmalloc_addr(ptr));
1088 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vmalloc_to_page(ptr));
1089
1090 #if !IS_MODULE(CONFIG_KASAN_KUNIT_TEST)
1091 {
1092 int rv;
1093
1094 /* Make sure vmalloc'ed memory permissions can be changed. */
1095 rv = set_memory_ro((unsigned long)ptr, 1);
1096 KUNIT_ASSERT_GE(test, rv, 0);
1097 rv = set_memory_rw((unsigned long)ptr, 1);
1098 KUNIT_ASSERT_GE(test, rv, 0);
1099 }
1100 #endif
1101
1102 vfree(ptr);
1103 }
1104
vmalloc_oob(struct kunit * test)1105 static void vmalloc_oob(struct kunit *test)
1106 {
1107 char *v_ptr, *p_ptr;
1108 struct page *page;
1109 size_t size = PAGE_SIZE / 2 - KASAN_GRANULE_SIZE - 5;
1110
1111 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1112
1113 v_ptr = vmalloc(size);
1114 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1115
1116 OPTIMIZER_HIDE_VAR(v_ptr);
1117
1118 /*
1119 * We have to be careful not to hit the guard page in vmalloc tests.
1120 * The MMU will catch that and crash us.
1121 */
1122
1123 /* Make sure in-bounds accesses are valid. */
1124 v_ptr[0] = 0;
1125 v_ptr[size - 1] = 0;
1126
1127 /*
1128 * An unaligned access past the requested vmalloc size.
1129 * Only generic KASAN can precisely detect these.
1130 */
1131 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
1132 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size]);
1133
1134 /* An aligned access into the first out-of-bounds granule. */
1135 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size + 5]);
1136
1137 /* Check that in-bounds accesses to the physical page are valid. */
1138 page = vmalloc_to_page(v_ptr);
1139 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
1140 p_ptr = page_address(page);
1141 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1142 p_ptr[0] = 0;
1143
1144 vfree(v_ptr);
1145
1146 /*
1147 * We can't check for use-after-unmap bugs in this nor in the following
1148 * vmalloc tests, as the page might be fully unmapped and accessing it
1149 * will crash the kernel.
1150 */
1151 }
1152
vmap_tags(struct kunit * test)1153 static void vmap_tags(struct kunit *test)
1154 {
1155 char *p_ptr, *v_ptr;
1156 struct page *p_page, *v_page;
1157
1158 /*
1159 * This test is specifically crafted for the software tag-based mode,
1160 * the only tag-based mode that poisons vmap mappings.
1161 */
1162 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
1163
1164 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1165
1166 p_page = alloc_pages(GFP_KERNEL, 1);
1167 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_page);
1168 p_ptr = page_address(p_page);
1169 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1170
1171 v_ptr = vmap(&p_page, 1, VM_MAP, PAGE_KERNEL);
1172 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1173
1174 /*
1175 * We can't check for out-of-bounds bugs in this nor in the following
1176 * vmalloc tests, as allocations have page granularity and accessing
1177 * the guard page will crash the kernel.
1178 */
1179
1180 KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
1181 KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL);
1182
1183 /* Make sure that in-bounds accesses through both pointers work. */
1184 *p_ptr = 0;
1185 *v_ptr = 0;
1186
1187 /* Make sure vmalloc_to_page() correctly recovers the page pointer. */
1188 v_page = vmalloc_to_page(v_ptr);
1189 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_page);
1190 KUNIT_EXPECT_PTR_EQ(test, p_page, v_page);
1191
1192 vunmap(v_ptr);
1193 free_pages((unsigned long)p_ptr, 1);
1194 }
1195
vm_map_ram_tags(struct kunit * test)1196 static void vm_map_ram_tags(struct kunit *test)
1197 {
1198 char *p_ptr, *v_ptr;
1199 struct page *page;
1200
1201 /*
1202 * This test is specifically crafted for the software tag-based mode,
1203 * the only tag-based mode that poisons vm_map_ram mappings.
1204 */
1205 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
1206
1207 page = alloc_pages(GFP_KERNEL, 1);
1208 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
1209 p_ptr = page_address(page);
1210 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1211
1212 v_ptr = vm_map_ram(&page, 1, -1);
1213 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1214
1215 KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
1216 KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL);
1217
1218 /* Make sure that in-bounds accesses through both pointers work. */
1219 *p_ptr = 0;
1220 *v_ptr = 0;
1221
1222 vm_unmap_ram(v_ptr, 1);
1223 free_pages((unsigned long)p_ptr, 1);
1224 }
1225
vmalloc_percpu(struct kunit * test)1226 static void vmalloc_percpu(struct kunit *test)
1227 {
1228 char __percpu *ptr;
1229 int cpu;
1230
1231 /*
1232 * This test is specifically crafted for the software tag-based mode,
1233 * the only tag-based mode that poisons percpu mappings.
1234 */
1235 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
1236
1237 ptr = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
1238
1239 for_each_possible_cpu(cpu) {
1240 char *c_ptr = per_cpu_ptr(ptr, cpu);
1241
1242 KUNIT_EXPECT_GE(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_MIN);
1243 KUNIT_EXPECT_LT(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_KERNEL);
1244
1245 /* Make sure that in-bounds accesses don't crash the kernel. */
1246 *c_ptr = 0;
1247 }
1248
1249 free_percpu(ptr);
1250 }
1251
1252 /*
1253 * Check that the assigned pointer tag falls within the [KASAN_TAG_MIN,
1254 * KASAN_TAG_KERNEL) range (note: excluding the match-all tag) for tag-based
1255 * modes.
1256 */
match_all_not_assigned(struct kunit * test)1257 static void match_all_not_assigned(struct kunit *test)
1258 {
1259 char *ptr;
1260 struct page *pages;
1261 int i, size, order;
1262
1263 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1264
1265 for (i = 0; i < 256; i++) {
1266 size = (get_random_int() % 1024) + 1;
1267 ptr = kmalloc(size, GFP_KERNEL);
1268 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1269 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1270 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1271 kfree(ptr);
1272 }
1273
1274 for (i = 0; i < 256; i++) {
1275 order = (get_random_int() % 4) + 1;
1276 pages = alloc_pages(GFP_KERNEL, order);
1277 ptr = page_address(pages);
1278 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1279 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1280 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1281 free_pages((unsigned long)ptr, order);
1282 }
1283
1284 if (!IS_ENABLED(CONFIG_KASAN_VMALLOC))
1285 return;
1286
1287 for (i = 0; i < 256; i++) {
1288 size = (get_random_int() % 1024) + 1;
1289 ptr = vmalloc(size);
1290 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1291 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1292 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1293 vfree(ptr);
1294 }
1295 }
1296
1297 /* Check that 0xff works as a match-all pointer tag for tag-based modes. */
match_all_ptr_tag(struct kunit * test)1298 static void match_all_ptr_tag(struct kunit *test)
1299 {
1300 char *ptr;
1301 u8 tag;
1302
1303 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1304
1305 ptr = kmalloc(128, GFP_KERNEL);
1306 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1307
1308 /* Backup the assigned tag. */
1309 tag = get_tag(ptr);
1310 KUNIT_EXPECT_NE(test, tag, (u8)KASAN_TAG_KERNEL);
1311
1312 /* Reset the tag to 0xff.*/
1313 ptr = set_tag(ptr, KASAN_TAG_KERNEL);
1314
1315 /* This access shouldn't trigger a KASAN report. */
1316 *ptr = 0;
1317
1318 /* Recover the pointer tag and free. */
1319 ptr = set_tag(ptr, tag);
1320 kfree(ptr);
1321 }
1322
1323 /* Check that there are no match-all memory tags for tag-based modes. */
match_all_mem_tag(struct kunit * test)1324 static void match_all_mem_tag(struct kunit *test)
1325 {
1326 char *ptr;
1327 int tag;
1328
1329 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1330
1331 ptr = kmalloc(128, GFP_KERNEL);
1332 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1333 KUNIT_EXPECT_NE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1334
1335 /* For each possible tag value not matching the pointer tag. */
1336 for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) {
1337 if (tag == get_tag(ptr))
1338 continue;
1339
1340 /* Mark the first memory granule with the chosen memory tag. */
1341 kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag, false);
1342
1343 /* This access must cause a KASAN report. */
1344 KUNIT_EXPECT_KASAN_FAIL(test, *ptr = 0);
1345 }
1346
1347 /* Recover the memory tag and free. */
1348 kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr), false);
1349 kfree(ptr);
1350 }
1351
1352 static struct kunit_case kasan_kunit_test_cases[] = {
1353 KUNIT_CASE(kmalloc_oob_right),
1354 KUNIT_CASE(kmalloc_oob_left),
1355 KUNIT_CASE(kmalloc_node_oob_right),
1356 KUNIT_CASE(kmalloc_pagealloc_oob_right),
1357 KUNIT_CASE(kmalloc_pagealloc_uaf),
1358 KUNIT_CASE(kmalloc_pagealloc_invalid_free),
1359 KUNIT_CASE(pagealloc_oob_right),
1360 KUNIT_CASE(pagealloc_uaf),
1361 KUNIT_CASE(kmalloc_large_oob_right),
1362 KUNIT_CASE(krealloc_more_oob),
1363 KUNIT_CASE(krealloc_less_oob),
1364 KUNIT_CASE(krealloc_pagealloc_more_oob),
1365 KUNIT_CASE(krealloc_pagealloc_less_oob),
1366 KUNIT_CASE(krealloc_uaf),
1367 KUNIT_CASE(kmalloc_oob_16),
1368 KUNIT_CASE(kmalloc_uaf_16),
1369 KUNIT_CASE(kmalloc_oob_in_memset),
1370 KUNIT_CASE(kmalloc_oob_memset_2),
1371 KUNIT_CASE(kmalloc_oob_memset_4),
1372 KUNIT_CASE(kmalloc_oob_memset_8),
1373 KUNIT_CASE(kmalloc_oob_memset_16),
1374 KUNIT_CASE(kmalloc_memmove_negative_size),
1375 KUNIT_CASE(kmalloc_memmove_invalid_size),
1376 KUNIT_CASE(kmalloc_uaf),
1377 KUNIT_CASE(kmalloc_uaf_memset),
1378 KUNIT_CASE(kmalloc_uaf2),
1379 KUNIT_CASE(kfree_via_page),
1380 KUNIT_CASE(kfree_via_phys),
1381 KUNIT_CASE(kmem_cache_oob),
1382 KUNIT_CASE(kmem_cache_accounted),
1383 KUNIT_CASE(kmem_cache_bulk),
1384 KUNIT_CASE(kasan_global_oob_right),
1385 KUNIT_CASE(kasan_global_oob_left),
1386 KUNIT_CASE(kasan_stack_oob),
1387 KUNIT_CASE(kasan_alloca_oob_left),
1388 KUNIT_CASE(kasan_alloca_oob_right),
1389 KUNIT_CASE(ksize_unpoisons_memory),
1390 KUNIT_CASE(ksize_uaf),
1391 KUNIT_CASE(kmem_cache_double_free),
1392 KUNIT_CASE(kmem_cache_invalid_free),
1393 KUNIT_CASE(kmem_cache_double_destroy),
1394 KUNIT_CASE(kasan_memchr),
1395 KUNIT_CASE(kasan_memcmp),
1396 KUNIT_CASE(kasan_strings),
1397 KUNIT_CASE(kasan_bitops_generic),
1398 KUNIT_CASE(kasan_bitops_tags),
1399 KUNIT_CASE(kmalloc_double_kzfree),
1400 KUNIT_CASE(vmalloc_helpers_tags),
1401 KUNIT_CASE(vmalloc_oob),
1402 KUNIT_CASE(vmap_tags),
1403 KUNIT_CASE(vm_map_ram_tags),
1404 KUNIT_CASE(vmalloc_percpu),
1405 KUNIT_CASE(match_all_not_assigned),
1406 KUNIT_CASE(match_all_ptr_tag),
1407 KUNIT_CASE(match_all_mem_tag),
1408 {}
1409 };
1410
1411 static struct kunit_suite kasan_kunit_test_suite = {
1412 .name = "kasan",
1413 .init = kasan_test_init,
1414 .test_cases = kasan_kunit_test_cases,
1415 .exit = kasan_test_exit,
1416 };
1417
1418 kunit_test_suite(kasan_kunit_test_suite);
1419
1420 MODULE_LICENSE("GPL");
1421