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_skip((test), "Test requires " #config "=y"); \
119 } while (0)
120
121 #define KASAN_TEST_NEEDS_CONFIG_OFF(test, config) do { \
122 if (IS_ENABLED(config)) \
123 kunit_skip((test), "Test requires " #config "=n"); \
124 } while (0)
125
kmalloc_oob_right(struct kunit * test)126 static void kmalloc_oob_right(struct kunit *test)
127 {
128 char *ptr;
129 size_t size = 128 - KASAN_GRANULE_SIZE - 5;
130
131 ptr = kmalloc(size, GFP_KERNEL);
132 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
133
134 OPTIMIZER_HIDE_VAR(ptr);
135 /*
136 * An unaligned access past the requested kmalloc size.
137 * Only generic KASAN can precisely detect these.
138 */
139 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
140 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x');
141
142 /*
143 * An aligned access into the first out-of-bounds granule that falls
144 * within the aligned kmalloc object.
145 */
146 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + 5] = 'y');
147
148 /* Out-of-bounds access past the aligned kmalloc object. */
149 KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] =
150 ptr[size + KASAN_GRANULE_SIZE + 5]);
151
152 kfree(ptr);
153 }
154
kmalloc_oob_left(struct kunit * test)155 static void kmalloc_oob_left(struct kunit *test)
156 {
157 char *ptr;
158 size_t size = 15;
159
160 ptr = kmalloc(size, GFP_KERNEL);
161 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
162
163 OPTIMIZER_HIDE_VAR(ptr);
164 KUNIT_EXPECT_KASAN_FAIL(test, *ptr = *(ptr - 1));
165 kfree(ptr);
166 }
167
kmalloc_node_oob_right(struct kunit * test)168 static void kmalloc_node_oob_right(struct kunit *test)
169 {
170 char *ptr;
171 size_t size = 4096;
172
173 ptr = kmalloc_node(size, GFP_KERNEL, 0);
174 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
175
176 OPTIMIZER_HIDE_VAR(ptr);
177 KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
178 kfree(ptr);
179 }
180
181 /*
182 * These kmalloc_pagealloc_* tests try allocating a memory chunk that doesn't
183 * fit into a slab cache and therefore is allocated via the page allocator
184 * fallback. Since this kind of fallback is only implemented for SLUB, these
185 * tests are limited to that allocator.
186 */
kmalloc_pagealloc_oob_right(struct kunit * test)187 static void kmalloc_pagealloc_oob_right(struct kunit *test)
188 {
189 char *ptr;
190 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
191
192 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
193
194 ptr = kmalloc(size, GFP_KERNEL);
195 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
196
197 OPTIMIZER_HIDE_VAR(ptr);
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 OPTIMIZER_HIDE_VAR(ptr);
279 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
280 kfree(ptr);
281 }
282
krealloc_more_oob_helper(struct kunit * test,size_t size1,size_t size2)283 static void krealloc_more_oob_helper(struct kunit *test,
284 size_t size1, size_t size2)
285 {
286 char *ptr1, *ptr2;
287 size_t middle;
288
289 KUNIT_ASSERT_LT(test, size1, size2);
290 middle = size1 + (size2 - size1) / 2;
291
292 ptr1 = kmalloc(size1, GFP_KERNEL);
293 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
294
295 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
296 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
297
298 /* All offsets up to size2 must be accessible. */
299 ptr2[size1 - 1] = 'x';
300 ptr2[size1] = 'x';
301 ptr2[middle] = 'x';
302 ptr2[size2 - 1] = 'x';
303
304 /* Generic mode is precise, so unaligned size2 must be inaccessible. */
305 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
306 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
307
308 /* For all modes first aligned offset after size2 must be inaccessible. */
309 KUNIT_EXPECT_KASAN_FAIL(test,
310 ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x');
311
312 kfree(ptr2);
313 }
314
krealloc_less_oob_helper(struct kunit * test,size_t size1,size_t size2)315 static void krealloc_less_oob_helper(struct kunit *test,
316 size_t size1, size_t size2)
317 {
318 char *ptr1, *ptr2;
319 size_t middle;
320
321 KUNIT_ASSERT_LT(test, size2, size1);
322 middle = size2 + (size1 - size2) / 2;
323
324 ptr1 = kmalloc(size1, GFP_KERNEL);
325 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
326
327 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
328 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
329
330 /* Must be accessible for all modes. */
331 ptr2[size2 - 1] = 'x';
332
333 /* Generic mode is precise, so unaligned size2 must be inaccessible. */
334 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
335 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
336
337 /* For all modes first aligned offset after size2 must be inaccessible. */
338 KUNIT_EXPECT_KASAN_FAIL(test,
339 ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x');
340
341 /*
342 * For all modes all size2, middle, and size1 should land in separate
343 * granules and thus the latter two offsets should be inaccessible.
344 */
345 KUNIT_EXPECT_LE(test, round_up(size2, KASAN_GRANULE_SIZE),
346 round_down(middle, KASAN_GRANULE_SIZE));
347 KUNIT_EXPECT_LE(test, round_up(middle, KASAN_GRANULE_SIZE),
348 round_down(size1, KASAN_GRANULE_SIZE));
349 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[middle] = 'x');
350 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1 - 1] = 'x');
351 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1] = 'x');
352
353 kfree(ptr2);
354 }
355
krealloc_more_oob(struct kunit * test)356 static void krealloc_more_oob(struct kunit *test)
357 {
358 krealloc_more_oob_helper(test, 201, 235);
359 }
360
krealloc_less_oob(struct kunit * test)361 static void krealloc_less_oob(struct kunit *test)
362 {
363 krealloc_less_oob_helper(test, 235, 201);
364 }
365
krealloc_pagealloc_more_oob(struct kunit * test)366 static void krealloc_pagealloc_more_oob(struct kunit *test)
367 {
368 /* page_alloc fallback in only implemented for SLUB. */
369 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
370
371 krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201,
372 KMALLOC_MAX_CACHE_SIZE + 235);
373 }
374
krealloc_pagealloc_less_oob(struct kunit * test)375 static void krealloc_pagealloc_less_oob(struct kunit *test)
376 {
377 /* page_alloc fallback in only implemented for SLUB. */
378 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
379
380 krealloc_less_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 235,
381 KMALLOC_MAX_CACHE_SIZE + 201);
382 }
383
384 /*
385 * Check that krealloc() detects a use-after-free, returns NULL,
386 * and doesn't unpoison the freed object.
387 */
krealloc_uaf(struct kunit * test)388 static void krealloc_uaf(struct kunit *test)
389 {
390 char *ptr1, *ptr2;
391 int size1 = 201;
392 int size2 = 235;
393
394 ptr1 = kmalloc(size1, GFP_KERNEL);
395 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
396 kfree(ptr1);
397
398 KUNIT_EXPECT_KASAN_FAIL(test, ptr2 = krealloc(ptr1, size2, GFP_KERNEL));
399 KUNIT_ASSERT_NULL(test, ptr2);
400 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)ptr1);
401 }
402
kmalloc_oob_16(struct kunit * test)403 static void kmalloc_oob_16(struct kunit *test)
404 {
405 struct {
406 u64 words[2];
407 } *ptr1, *ptr2;
408
409 /* This test is specifically crafted for the generic mode. */
410 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
411
412 ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
413 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
414
415 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
416 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
417
418 OPTIMIZER_HIDE_VAR(ptr1);
419 OPTIMIZER_HIDE_VAR(ptr2);
420 KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
421 kfree(ptr1);
422 kfree(ptr2);
423 }
424
kmalloc_uaf_16(struct kunit * test)425 static void kmalloc_uaf_16(struct kunit *test)
426 {
427 struct {
428 u64 words[2];
429 } *ptr1, *ptr2;
430
431 ptr1 = kmalloc(sizeof(*ptr1), GFP_KERNEL);
432 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
433
434 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
435 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
436 kfree(ptr2);
437
438 KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
439 kfree(ptr1);
440 }
441
442 /*
443 * Note: in the memset tests below, the written range touches both valid and
444 * invalid memory. This makes sure that the instrumentation does not only check
445 * the starting address but the whole range.
446 */
447
kmalloc_oob_memset_2(struct kunit * test)448 static void kmalloc_oob_memset_2(struct kunit *test)
449 {
450 char *ptr;
451 size_t size = 128 - KASAN_GRANULE_SIZE;
452
453 ptr = kmalloc(size, GFP_KERNEL);
454 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
455
456 OPTIMIZER_HIDE_VAR(size);
457 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, 2));
458 kfree(ptr);
459 }
460
kmalloc_oob_memset_4(struct kunit * test)461 static void kmalloc_oob_memset_4(struct kunit *test)
462 {
463 char *ptr;
464 size_t size = 128 - KASAN_GRANULE_SIZE;
465
466 ptr = kmalloc(size, GFP_KERNEL);
467 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
468
469 OPTIMIZER_HIDE_VAR(size);
470 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, 4));
471 kfree(ptr);
472 }
473
kmalloc_oob_memset_8(struct kunit * test)474 static void kmalloc_oob_memset_8(struct kunit *test)
475 {
476 char *ptr;
477 size_t size = 128 - KASAN_GRANULE_SIZE;
478
479 ptr = kmalloc(size, GFP_KERNEL);
480 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
481
482 OPTIMIZER_HIDE_VAR(size);
483 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, 8));
484 kfree(ptr);
485 }
486
kmalloc_oob_memset_16(struct kunit * test)487 static void kmalloc_oob_memset_16(struct kunit *test)
488 {
489 char *ptr;
490 size_t size = 128 - KASAN_GRANULE_SIZE;
491
492 ptr = kmalloc(size, GFP_KERNEL);
493 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
494
495 OPTIMIZER_HIDE_VAR(size);
496 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, 16));
497 kfree(ptr);
498 }
499
kmalloc_oob_in_memset(struct kunit * test)500 static void kmalloc_oob_in_memset(struct kunit *test)
501 {
502 char *ptr;
503 size_t size = 128 - KASAN_GRANULE_SIZE;
504
505 ptr = kmalloc(size, GFP_KERNEL);
506 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
507
508 OPTIMIZER_HIDE_VAR(ptr);
509 OPTIMIZER_HIDE_VAR(size);
510 KUNIT_EXPECT_KASAN_FAIL(test,
511 memset(ptr, 0, size + KASAN_GRANULE_SIZE));
512 kfree(ptr);
513 }
514
kmalloc_memmove_negative_size(struct kunit * test)515 static void kmalloc_memmove_negative_size(struct kunit *test)
516 {
517 char *ptr;
518 size_t size = 64;
519 size_t invalid_size = -2;
520
521 /*
522 * Hardware tag-based mode doesn't check memmove for negative size.
523 * As a result, this test introduces a side-effect memory corruption,
524 * which can result in a crash.
525 */
526 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);
527
528 ptr = kmalloc(size, GFP_KERNEL);
529 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
530
531 memset((char *)ptr, 0, 64);
532 OPTIMIZER_HIDE_VAR(ptr);
533 OPTIMIZER_HIDE_VAR(invalid_size);
534 KUNIT_EXPECT_KASAN_FAIL(test,
535 memmove((char *)ptr, (char *)ptr + 4, invalid_size));
536 kfree(ptr);
537 }
538
kmalloc_memmove_invalid_size(struct kunit * test)539 static void kmalloc_memmove_invalid_size(struct kunit *test)
540 {
541 char *ptr;
542 size_t size = 64;
543 volatile size_t invalid_size = size;
544
545 ptr = kmalloc(size, GFP_KERNEL);
546 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
547
548 memset((char *)ptr, 0, 64);
549 OPTIMIZER_HIDE_VAR(ptr);
550 KUNIT_EXPECT_KASAN_FAIL(test,
551 memmove((char *)ptr, (char *)ptr + 4, invalid_size));
552 kfree(ptr);
553 }
554
kmalloc_uaf(struct kunit * test)555 static void kmalloc_uaf(struct kunit *test)
556 {
557 char *ptr;
558 size_t size = 10;
559
560 ptr = kmalloc(size, GFP_KERNEL);
561 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
562
563 kfree(ptr);
564 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[8]);
565 }
566
kmalloc_uaf_memset(struct kunit * test)567 static void kmalloc_uaf_memset(struct kunit *test)
568 {
569 char *ptr;
570 size_t size = 33;
571
572 /*
573 * Only generic KASAN uses quarantine, which is required to avoid a
574 * kernel memory corruption this test causes.
575 */
576 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
577
578 ptr = kmalloc(size, GFP_KERNEL);
579 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
580
581 kfree(ptr);
582 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size));
583 }
584
kmalloc_uaf2(struct kunit * test)585 static void kmalloc_uaf2(struct kunit *test)
586 {
587 char *ptr1, *ptr2;
588 size_t size = 43;
589 int counter = 0;
590
591 again:
592 ptr1 = kmalloc(size, GFP_KERNEL);
593 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
594
595 kfree(ptr1);
596
597 ptr2 = kmalloc(size, GFP_KERNEL);
598 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
599
600 /*
601 * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same.
602 * Allow up to 16 attempts at generating different tags.
603 */
604 if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 16) {
605 kfree(ptr2);
606 goto again;
607 }
608
609 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[40]);
610 KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
611
612 kfree(ptr2);
613 }
614
kfree_via_page(struct kunit * test)615 static void kfree_via_page(struct kunit *test)
616 {
617 char *ptr;
618 size_t size = 8;
619 struct page *page;
620 unsigned long offset;
621
622 ptr = kmalloc(size, GFP_KERNEL);
623 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
624
625 page = virt_to_page(ptr);
626 offset = offset_in_page(ptr);
627 kfree(page_address(page) + offset);
628 }
629
kfree_via_phys(struct kunit * test)630 static void kfree_via_phys(struct kunit *test)
631 {
632 char *ptr;
633 size_t size = 8;
634 phys_addr_t phys;
635
636 ptr = kmalloc(size, GFP_KERNEL);
637 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
638
639 phys = virt_to_phys(ptr);
640 kfree(phys_to_virt(phys));
641 }
642
kmem_cache_oob(struct kunit * test)643 static void kmem_cache_oob(struct kunit *test)
644 {
645 char *p;
646 size_t size = 200;
647 struct kmem_cache *cache;
648
649 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
650 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
651
652 p = kmem_cache_alloc(cache, GFP_KERNEL);
653 if (!p) {
654 kunit_err(test, "Allocation failed: %s\n", __func__);
655 kmem_cache_destroy(cache);
656 return;
657 }
658
659 KUNIT_EXPECT_KASAN_FAIL(test, *p = p[size + OOB_TAG_OFF]);
660
661 kmem_cache_free(cache, p);
662 kmem_cache_destroy(cache);
663 }
664
kmem_cache_accounted(struct kunit * test)665 static void kmem_cache_accounted(struct kunit *test)
666 {
667 int i;
668 char *p;
669 size_t size = 200;
670 struct kmem_cache *cache;
671
672 cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
673 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
674
675 /*
676 * Several allocations with a delay to allow for lazy per memcg kmem
677 * cache creation.
678 */
679 for (i = 0; i < 5; i++) {
680 p = kmem_cache_alloc(cache, GFP_KERNEL);
681 if (!p)
682 goto free_cache;
683
684 kmem_cache_free(cache, p);
685 msleep(100);
686 }
687
688 free_cache:
689 kmem_cache_destroy(cache);
690 }
691
kmem_cache_bulk(struct kunit * test)692 static void kmem_cache_bulk(struct kunit *test)
693 {
694 struct kmem_cache *cache;
695 size_t size = 200;
696 char *p[10];
697 bool ret;
698 int i;
699
700 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
701 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
702
703 ret = kmem_cache_alloc_bulk(cache, GFP_KERNEL, ARRAY_SIZE(p), (void **)&p);
704 if (!ret) {
705 kunit_err(test, "Allocation failed: %s\n", __func__);
706 kmem_cache_destroy(cache);
707 return;
708 }
709
710 for (i = 0; i < ARRAY_SIZE(p); i++)
711 p[i][0] = p[i][size - 1] = 42;
712
713 kmem_cache_free_bulk(cache, ARRAY_SIZE(p), (void **)&p);
714 kmem_cache_destroy(cache);
715 }
716
717 static char global_array[10];
718
kasan_global_oob_right(struct kunit * test)719 static void kasan_global_oob_right(struct kunit *test)
720 {
721 /*
722 * Deliberate out-of-bounds access. To prevent CONFIG_UBSAN_LOCAL_BOUNDS
723 * from failing here and panicking the kernel, access the array via a
724 * volatile pointer, which will prevent the compiler from being able to
725 * determine the array bounds.
726 *
727 * This access uses a volatile pointer to char (char *volatile) rather
728 * than the more conventional pointer to volatile char (volatile char *)
729 * because we want to prevent the compiler from making inferences about
730 * the pointer itself (i.e. its array bounds), not the data that it
731 * refers to.
732 */
733 char *volatile array = global_array;
734 char *p = &array[ARRAY_SIZE(global_array) + 3];
735
736 /* Only generic mode instruments globals. */
737 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
738
739 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
740 }
741
kasan_global_oob_left(struct kunit * test)742 static void kasan_global_oob_left(struct kunit *test)
743 {
744 char *volatile array = global_array;
745 char *p = array - 3;
746
747 /*
748 * GCC is known to fail this test, skip it.
749 * See https://bugzilla.kernel.org/show_bug.cgi?id=215051.
750 */
751 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_CC_IS_CLANG);
752 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
753 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
754 }
755
756 /* Check that ksize() makes the whole object accessible. */
ksize_unpoisons_memory(struct kunit * test)757 static void ksize_unpoisons_memory(struct kunit *test)
758 {
759 char *ptr;
760 size_t size = 123, real_size;
761
762 ptr = kmalloc(size, GFP_KERNEL);
763 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
764 real_size = ksize(ptr);
765
766 OPTIMIZER_HIDE_VAR(ptr);
767
768 /* This access shouldn't trigger a KASAN report. */
769 ptr[size] = 'x';
770
771 /* This one must. */
772 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size]);
773
774 kfree(ptr);
775 }
776
777 /*
778 * Check that a use-after-free is detected by ksize() and via normal accesses
779 * after it.
780 */
ksize_uaf(struct kunit * test)781 static void ksize_uaf(struct kunit *test)
782 {
783 char *ptr;
784 int size = 128 - KASAN_GRANULE_SIZE;
785
786 ptr = kmalloc(size, GFP_KERNEL);
787 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
788 kfree(ptr);
789
790 OPTIMIZER_HIDE_VAR(ptr);
791 KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
792 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
793 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
794 }
795
kasan_stack_oob(struct kunit * test)796 static void kasan_stack_oob(struct kunit *test)
797 {
798 char stack_array[10];
799 /* See comment in kasan_global_oob_right. */
800 char *volatile array = stack_array;
801 char *p = &array[ARRAY_SIZE(stack_array) + OOB_TAG_OFF];
802
803 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
804
805 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
806 }
807
kasan_alloca_oob_left(struct kunit * test)808 static void kasan_alloca_oob_left(struct kunit *test)
809 {
810 volatile int i = 10;
811 char alloca_array[i];
812 /* See comment in kasan_global_oob_right. */
813 char *volatile array = alloca_array;
814 char *p = array - 1;
815
816 /* Only generic mode instruments dynamic allocas. */
817 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
818 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
819
820 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
821 }
822
kasan_alloca_oob_right(struct kunit * test)823 static void kasan_alloca_oob_right(struct kunit *test)
824 {
825 volatile int i = 10;
826 char alloca_array[i];
827 /* See comment in kasan_global_oob_right. */
828 char *volatile array = alloca_array;
829 char *p = array + i;
830
831 /* Only generic mode instruments dynamic allocas. */
832 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
833 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
834
835 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
836 }
837
kmem_cache_double_free(struct kunit * test)838 static void kmem_cache_double_free(struct kunit *test)
839 {
840 char *p;
841 size_t size = 200;
842 struct kmem_cache *cache;
843
844 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
845 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
846
847 p = kmem_cache_alloc(cache, GFP_KERNEL);
848 if (!p) {
849 kunit_err(test, "Allocation failed: %s\n", __func__);
850 kmem_cache_destroy(cache);
851 return;
852 }
853
854 kmem_cache_free(cache, p);
855 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p));
856 kmem_cache_destroy(cache);
857 }
858
kmem_cache_invalid_free(struct kunit * test)859 static void kmem_cache_invalid_free(struct kunit *test)
860 {
861 char *p;
862 size_t size = 200;
863 struct kmem_cache *cache;
864
865 cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
866 NULL);
867 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
868
869 p = kmem_cache_alloc(cache, GFP_KERNEL);
870 if (!p) {
871 kunit_err(test, "Allocation failed: %s\n", __func__);
872 kmem_cache_destroy(cache);
873 return;
874 }
875
876 /* Trigger invalid free, the object doesn't get freed. */
877 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));
878
879 /*
880 * Properly free the object to prevent the "Objects remaining in
881 * test_cache on __kmem_cache_shutdown" BUG failure.
882 */
883 kmem_cache_free(cache, p);
884
885 kmem_cache_destroy(cache);
886 }
887
empty_cache_ctor(void * object)888 static void empty_cache_ctor(void *object) { }
889
kmem_cache_double_destroy(struct kunit * test)890 static void kmem_cache_double_destroy(struct kunit *test)
891 {
892 struct kmem_cache *cache;
893
894 /* Provide a constructor to prevent cache merging. */
895 cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor);
896 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
897 kmem_cache_destroy(cache);
898 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache));
899 }
900
kasan_memchr(struct kunit * test)901 static void kasan_memchr(struct kunit *test)
902 {
903 char *ptr;
904 size_t size = 24;
905
906 /*
907 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
908 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
909 */
910 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
911
912 if (OOB_TAG_OFF)
913 size = round_up(size, OOB_TAG_OFF);
914
915 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
916 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
917
918 OPTIMIZER_HIDE_VAR(ptr);
919 OPTIMIZER_HIDE_VAR(size);
920 KUNIT_EXPECT_KASAN_FAIL(test,
921 kasan_ptr_result = memchr(ptr, '1', size + 1));
922
923 kfree(ptr);
924 }
925
kasan_memcmp(struct kunit * test)926 static void kasan_memcmp(struct kunit *test)
927 {
928 char *ptr;
929 size_t size = 24;
930 int arr[9];
931
932 /*
933 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
934 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
935 */
936 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
937
938 if (OOB_TAG_OFF)
939 size = round_up(size, OOB_TAG_OFF);
940
941 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
942 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
943 memset(arr, 0, sizeof(arr));
944
945 OPTIMIZER_HIDE_VAR(ptr);
946 OPTIMIZER_HIDE_VAR(size);
947 KUNIT_EXPECT_KASAN_FAIL(test,
948 kasan_int_result = memcmp(ptr, arr, size+1));
949 kfree(ptr);
950 }
951
kasan_strings(struct kunit * test)952 static void kasan_strings(struct kunit *test)
953 {
954 char *ptr;
955 size_t size = 24;
956
957 /*
958 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
959 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
960 */
961 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
962
963 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
964 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
965
966 kfree(ptr);
967
968 /*
969 * Try to cause only 1 invalid access (less spam in dmesg).
970 * For that we need ptr to point to zeroed byte.
971 * Skip metadata that could be stored in freed object so ptr
972 * will likely point to zeroed byte.
973 */
974 ptr += 16;
975 KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strchr(ptr, '1'));
976
977 KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strrchr(ptr, '1'));
978
979 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strcmp(ptr, "2"));
980
981 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strncmp(ptr, "2", 1));
982
983 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strlen(ptr));
984
985 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strnlen(ptr, 1));
986 }
987
kasan_bitops_modify(struct kunit * test,int nr,void * addr)988 static void kasan_bitops_modify(struct kunit *test, int nr, void *addr)
989 {
990 KUNIT_EXPECT_KASAN_FAIL(test, set_bit(nr, addr));
991 KUNIT_EXPECT_KASAN_FAIL(test, __set_bit(nr, addr));
992 KUNIT_EXPECT_KASAN_FAIL(test, clear_bit(nr, addr));
993 KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit(nr, addr));
994 KUNIT_EXPECT_KASAN_FAIL(test, clear_bit_unlock(nr, addr));
995 KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit_unlock(nr, addr));
996 KUNIT_EXPECT_KASAN_FAIL(test, change_bit(nr, addr));
997 KUNIT_EXPECT_KASAN_FAIL(test, __change_bit(nr, addr));
998 }
999
kasan_bitops_test_and_modify(struct kunit * test,int nr,void * addr)1000 static void kasan_bitops_test_and_modify(struct kunit *test, int nr, void *addr)
1001 {
1002 KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit(nr, addr));
1003 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_set_bit(nr, addr));
1004 KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit_lock(nr, addr));
1005 KUNIT_EXPECT_KASAN_FAIL(test, test_and_clear_bit(nr, addr));
1006 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_clear_bit(nr, addr));
1007 KUNIT_EXPECT_KASAN_FAIL(test, test_and_change_bit(nr, addr));
1008 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_change_bit(nr, addr));
1009 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = test_bit(nr, addr));
1010
1011 #if defined(clear_bit_unlock_is_negative_byte)
1012 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result =
1013 clear_bit_unlock_is_negative_byte(nr, addr));
1014 #endif
1015 }
1016
kasan_bitops_generic(struct kunit * test)1017 static void kasan_bitops_generic(struct kunit *test)
1018 {
1019 long *bits;
1020
1021 /* This test is specifically crafted for the generic mode. */
1022 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
1023
1024 /*
1025 * Allocate 1 more byte, which causes kzalloc to round up to 16 bytes;
1026 * this way we do not actually corrupt other memory.
1027 */
1028 bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL);
1029 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
1030
1031 /*
1032 * Below calls try to access bit within allocated memory; however, the
1033 * below accesses are still out-of-bounds, since bitops are defined to
1034 * operate on the whole long the bit is in.
1035 */
1036 kasan_bitops_modify(test, BITS_PER_LONG, bits);
1037
1038 /*
1039 * Below calls try to access bit beyond allocated memory.
1040 */
1041 kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, bits);
1042
1043 kfree(bits);
1044 }
1045
kasan_bitops_tags(struct kunit * test)1046 static void kasan_bitops_tags(struct kunit *test)
1047 {
1048 long *bits;
1049
1050 /* This test is specifically crafted for tag-based modes. */
1051 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1052
1053 /* kmalloc-64 cache will be used and the last 16 bytes will be the redzone. */
1054 bits = kzalloc(48, GFP_KERNEL);
1055 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
1056
1057 /* Do the accesses past the 48 allocated bytes, but within the redone. */
1058 kasan_bitops_modify(test, BITS_PER_LONG, (void *)bits + 48);
1059 kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, (void *)bits + 48);
1060
1061 kfree(bits);
1062 }
1063
kmalloc_double_kzfree(struct kunit * test)1064 static void kmalloc_double_kzfree(struct kunit *test)
1065 {
1066 char *ptr;
1067 size_t size = 16;
1068
1069 ptr = kmalloc(size, GFP_KERNEL);
1070 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1071
1072 kfree_sensitive(ptr);
1073 KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr));
1074 }
1075
vmalloc_helpers_tags(struct kunit * test)1076 static void vmalloc_helpers_tags(struct kunit *test)
1077 {
1078 void *ptr;
1079
1080 /* This test is intended for tag-based modes. */
1081 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1082
1083 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1084
1085 ptr = vmalloc(PAGE_SIZE);
1086 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1087
1088 /* Check that the returned pointer is tagged. */
1089 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1090 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1091
1092 /* Make sure exported vmalloc helpers handle tagged pointers. */
1093 KUNIT_ASSERT_TRUE(test, is_vmalloc_addr(ptr));
1094 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vmalloc_to_page(ptr));
1095
1096 #if !IS_MODULE(CONFIG_KASAN_KUNIT_TEST)
1097 {
1098 int rv;
1099
1100 /* Make sure vmalloc'ed memory permissions can be changed. */
1101 rv = set_memory_ro((unsigned long)ptr, 1);
1102 KUNIT_ASSERT_GE(test, rv, 0);
1103 rv = set_memory_rw((unsigned long)ptr, 1);
1104 KUNIT_ASSERT_GE(test, rv, 0);
1105 }
1106 #endif
1107
1108 vfree(ptr);
1109 }
1110
vmalloc_oob(struct kunit * test)1111 static void vmalloc_oob(struct kunit *test)
1112 {
1113 char *v_ptr, *p_ptr;
1114 struct page *page;
1115 size_t size = PAGE_SIZE / 2 - KASAN_GRANULE_SIZE - 5;
1116
1117 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1118
1119 v_ptr = vmalloc(size);
1120 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1121
1122 OPTIMIZER_HIDE_VAR(v_ptr);
1123
1124 /*
1125 * We have to be careful not to hit the guard page in vmalloc tests.
1126 * The MMU will catch that and crash us.
1127 */
1128
1129 /* Make sure in-bounds accesses are valid. */
1130 v_ptr[0] = 0;
1131 v_ptr[size - 1] = 0;
1132
1133 /*
1134 * An unaligned access past the requested vmalloc size.
1135 * Only generic KASAN can precisely detect these.
1136 */
1137 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
1138 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size]);
1139
1140 /* An aligned access into the first out-of-bounds granule. */
1141 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size + 5]);
1142
1143 /* Check that in-bounds accesses to the physical page are valid. */
1144 page = vmalloc_to_page(v_ptr);
1145 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
1146 p_ptr = page_address(page);
1147 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1148 p_ptr[0] = 0;
1149
1150 vfree(v_ptr);
1151
1152 /*
1153 * We can't check for use-after-unmap bugs in this nor in the following
1154 * vmalloc tests, as the page might be fully unmapped and accessing it
1155 * will crash the kernel.
1156 */
1157 }
1158
vmap_tags(struct kunit * test)1159 static void vmap_tags(struct kunit *test)
1160 {
1161 char *p_ptr, *v_ptr;
1162 struct page *p_page, *v_page;
1163
1164 /*
1165 * This test is specifically crafted for the software tag-based mode,
1166 * the only tag-based mode that poisons vmap mappings.
1167 */
1168 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
1169
1170 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1171
1172 p_page = alloc_pages(GFP_KERNEL, 1);
1173 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_page);
1174 p_ptr = page_address(p_page);
1175 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1176
1177 v_ptr = vmap(&p_page, 1, VM_MAP, PAGE_KERNEL);
1178 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1179
1180 /*
1181 * We can't check for out-of-bounds bugs in this nor in the following
1182 * vmalloc tests, as allocations have page granularity and accessing
1183 * the guard page will crash the kernel.
1184 */
1185
1186 KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
1187 KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL);
1188
1189 /* Make sure that in-bounds accesses through both pointers work. */
1190 *p_ptr = 0;
1191 *v_ptr = 0;
1192
1193 /* Make sure vmalloc_to_page() correctly recovers the page pointer. */
1194 v_page = vmalloc_to_page(v_ptr);
1195 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_page);
1196 KUNIT_EXPECT_PTR_EQ(test, p_page, v_page);
1197
1198 vunmap(v_ptr);
1199 free_pages((unsigned long)p_ptr, 1);
1200 }
1201
vm_map_ram_tags(struct kunit * test)1202 static void vm_map_ram_tags(struct kunit *test)
1203 {
1204 char *p_ptr, *v_ptr;
1205 struct page *page;
1206
1207 /*
1208 * This test is specifically crafted for the software tag-based mode,
1209 * the only tag-based mode that poisons vm_map_ram mappings.
1210 */
1211 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
1212
1213 page = alloc_pages(GFP_KERNEL, 1);
1214 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
1215 p_ptr = page_address(page);
1216 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1217
1218 v_ptr = vm_map_ram(&page, 1, -1);
1219 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1220
1221 KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
1222 KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL);
1223
1224 /* Make sure that in-bounds accesses through both pointers work. */
1225 *p_ptr = 0;
1226 *v_ptr = 0;
1227
1228 vm_unmap_ram(v_ptr, 1);
1229 free_pages((unsigned long)p_ptr, 1);
1230 }
1231
vmalloc_percpu(struct kunit * test)1232 static void vmalloc_percpu(struct kunit *test)
1233 {
1234 char __percpu *ptr;
1235 int cpu;
1236
1237 /*
1238 * This test is specifically crafted for the software tag-based mode,
1239 * the only tag-based mode that poisons percpu mappings.
1240 */
1241 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
1242
1243 ptr = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
1244
1245 for_each_possible_cpu(cpu) {
1246 char *c_ptr = per_cpu_ptr(ptr, cpu);
1247
1248 KUNIT_EXPECT_GE(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_MIN);
1249 KUNIT_EXPECT_LT(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_KERNEL);
1250
1251 /* Make sure that in-bounds accesses don't crash the kernel. */
1252 *c_ptr = 0;
1253 }
1254
1255 free_percpu(ptr);
1256 }
1257
1258 /*
1259 * Check that the assigned pointer tag falls within the [KASAN_TAG_MIN,
1260 * KASAN_TAG_KERNEL) range (note: excluding the match-all tag) for tag-based
1261 * modes.
1262 */
match_all_not_assigned(struct kunit * test)1263 static void match_all_not_assigned(struct kunit *test)
1264 {
1265 char *ptr;
1266 struct page *pages;
1267 int i, size, order;
1268
1269 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1270
1271 for (i = 0; i < 256; i++) {
1272 size = (get_random_int() % 1024) + 1;
1273 ptr = kmalloc(size, GFP_KERNEL);
1274 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1275 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1276 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1277 kfree(ptr);
1278 }
1279
1280 for (i = 0; i < 256; i++) {
1281 order = (get_random_int() % 4) + 1;
1282 pages = alloc_pages(GFP_KERNEL, order);
1283 ptr = page_address(pages);
1284 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1285 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1286 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1287 free_pages((unsigned long)ptr, order);
1288 }
1289
1290 if (!IS_ENABLED(CONFIG_KASAN_VMALLOC))
1291 return;
1292
1293 for (i = 0; i < 256; i++) {
1294 size = (get_random_int() % 1024) + 1;
1295 ptr = vmalloc(size);
1296 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1297 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1298 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1299 vfree(ptr);
1300 }
1301 }
1302
1303 /* Check that 0xff works as a match-all pointer tag for tag-based modes. */
match_all_ptr_tag(struct kunit * test)1304 static void match_all_ptr_tag(struct kunit *test)
1305 {
1306 char *ptr;
1307 u8 tag;
1308
1309 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1310
1311 ptr = kmalloc(128, GFP_KERNEL);
1312 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1313
1314 /* Backup the assigned tag. */
1315 tag = get_tag(ptr);
1316 KUNIT_EXPECT_NE(test, tag, (u8)KASAN_TAG_KERNEL);
1317
1318 /* Reset the tag to 0xff.*/
1319 ptr = set_tag(ptr, KASAN_TAG_KERNEL);
1320
1321 /* This access shouldn't trigger a KASAN report. */
1322 *ptr = 0;
1323
1324 /* Recover the pointer tag and free. */
1325 ptr = set_tag(ptr, tag);
1326 kfree(ptr);
1327 }
1328
1329 /* Check that there are no match-all memory tags for tag-based modes. */
match_all_mem_tag(struct kunit * test)1330 static void match_all_mem_tag(struct kunit *test)
1331 {
1332 char *ptr;
1333 int tag;
1334
1335 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1336
1337 ptr = kmalloc(128, GFP_KERNEL);
1338 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1339 KUNIT_EXPECT_NE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1340
1341 /* For each possible tag value not matching the pointer tag. */
1342 for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) {
1343 if (tag == get_tag(ptr))
1344 continue;
1345
1346 /* Mark the first memory granule with the chosen memory tag. */
1347 kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag, false);
1348
1349 /* This access must cause a KASAN report. */
1350 KUNIT_EXPECT_KASAN_FAIL(test, *ptr = 0);
1351 }
1352
1353 /* Recover the memory tag and free. */
1354 kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr), false);
1355 kfree(ptr);
1356 }
1357
1358 static struct kunit_case kasan_kunit_test_cases[] = {
1359 KUNIT_CASE(kmalloc_oob_right),
1360 KUNIT_CASE(kmalloc_oob_left),
1361 KUNIT_CASE(kmalloc_node_oob_right),
1362 KUNIT_CASE(kmalloc_pagealloc_oob_right),
1363 KUNIT_CASE(kmalloc_pagealloc_uaf),
1364 KUNIT_CASE(kmalloc_pagealloc_invalid_free),
1365 KUNIT_CASE(pagealloc_oob_right),
1366 KUNIT_CASE(pagealloc_uaf),
1367 KUNIT_CASE(kmalloc_large_oob_right),
1368 KUNIT_CASE(krealloc_more_oob),
1369 KUNIT_CASE(krealloc_less_oob),
1370 KUNIT_CASE(krealloc_pagealloc_more_oob),
1371 KUNIT_CASE(krealloc_pagealloc_less_oob),
1372 KUNIT_CASE(krealloc_uaf),
1373 KUNIT_CASE(kmalloc_oob_16),
1374 KUNIT_CASE(kmalloc_uaf_16),
1375 KUNIT_CASE(kmalloc_oob_in_memset),
1376 KUNIT_CASE(kmalloc_oob_memset_2),
1377 KUNIT_CASE(kmalloc_oob_memset_4),
1378 KUNIT_CASE(kmalloc_oob_memset_8),
1379 KUNIT_CASE(kmalloc_oob_memset_16),
1380 KUNIT_CASE(kmalloc_memmove_negative_size),
1381 KUNIT_CASE(kmalloc_memmove_invalid_size),
1382 KUNIT_CASE(kmalloc_uaf),
1383 KUNIT_CASE(kmalloc_uaf_memset),
1384 KUNIT_CASE(kmalloc_uaf2),
1385 KUNIT_CASE(kfree_via_page),
1386 KUNIT_CASE(kfree_via_phys),
1387 KUNIT_CASE(kmem_cache_oob),
1388 KUNIT_CASE(kmem_cache_accounted),
1389 KUNIT_CASE(kmem_cache_bulk),
1390 KUNIT_CASE(kasan_global_oob_right),
1391 KUNIT_CASE(kasan_global_oob_left),
1392 KUNIT_CASE(kasan_stack_oob),
1393 KUNIT_CASE(kasan_alloca_oob_left),
1394 KUNIT_CASE(kasan_alloca_oob_right),
1395 KUNIT_CASE(ksize_unpoisons_memory),
1396 KUNIT_CASE(ksize_uaf),
1397 KUNIT_CASE(kmem_cache_double_free),
1398 KUNIT_CASE(kmem_cache_invalid_free),
1399 KUNIT_CASE(kmem_cache_double_destroy),
1400 KUNIT_CASE(kasan_memchr),
1401 KUNIT_CASE(kasan_memcmp),
1402 KUNIT_CASE(kasan_strings),
1403 KUNIT_CASE(kasan_bitops_generic),
1404 KUNIT_CASE(kasan_bitops_tags),
1405 KUNIT_CASE(kmalloc_double_kzfree),
1406 KUNIT_CASE(vmalloc_helpers_tags),
1407 KUNIT_CASE(vmalloc_oob),
1408 KUNIT_CASE(vmap_tags),
1409 KUNIT_CASE(vm_map_ram_tags),
1410 KUNIT_CASE(vmalloc_percpu),
1411 KUNIT_CASE(match_all_not_assigned),
1412 KUNIT_CASE(match_all_ptr_tag),
1413 KUNIT_CASE(match_all_mem_tag),
1414 {}
1415 };
1416
1417 static struct kunit_suite kasan_kunit_test_suite = {
1418 .name = "kasan",
1419 .init = kasan_test_init,
1420 .test_cases = kasan_kunit_test_cases,
1421 .exit = kasan_test_exit,
1422 };
1423
1424 kunit_test_suite(kasan_kunit_test_suite);
1425
1426 MODULE_LICENSE("GPL");
1427