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 #define pr_fmt(fmt) "kasan_test: " fmt
9
10 #include <kunit/test.h>
11 #include <linux/bitops.h>
12 #include <linux/delay.h>
13 #include <linux/io.h>
14 #include <linux/kasan.h>
15 #include <linux/kernel.h>
16 #include <linux/mm.h>
17 #include <linux/mman.h>
18 #include <linux/module.h>
19 #include <linux/printk.h>
20 #include <linux/random.h>
21 #include <linux/set_memory.h>
22 #include <linux/slab.h>
23 #include <linux/string.h>
24 #include <linux/tracepoint.h>
25 #include <linux/uaccess.h>
26 #include <linux/vmalloc.h>
27 #include <trace/events/printk.h>
28
29 #include <asm/page.h>
30
31 #include "kasan.h"
32
33 #define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
34
35 static bool multishot;
36
37 /* Fields set based on lines observed in the console. */
38 static struct {
39 bool report_found;
40 bool async_fault;
41 } test_status;
42
43 /*
44 * Some tests use these global variables to store return values from function
45 * calls that could otherwise be eliminated by the compiler as dead code.
46 */
47 void *kasan_ptr_result;
48 int kasan_int_result;
49
50 /* Probe for console output: obtains test_status lines of interest. */
probe_console(void * ignore,const char * buf,size_t len)51 static void probe_console(void *ignore, const char *buf, size_t len)
52 {
53 if (strnstr(buf, "BUG: KASAN: ", len))
54 WRITE_ONCE(test_status.report_found, true);
55 else if (strnstr(buf, "Asynchronous fault: ", len))
56 WRITE_ONCE(test_status.async_fault, true);
57 }
58
kasan_suite_init(struct kunit_suite * suite)59 static int kasan_suite_init(struct kunit_suite *suite)
60 {
61 if (!kasan_enabled()) {
62 pr_err("Can't run KASAN tests with KASAN disabled");
63 return -1;
64 }
65
66 /* Stop failing KUnit tests on KASAN reports. */
67 kasan_kunit_test_suite_start();
68
69 /*
70 * Temporarily enable multi-shot mode. Otherwise, KASAN would only
71 * report the first detected bug and panic the kernel if panic_on_warn
72 * is enabled.
73 */
74 multishot = kasan_save_enable_multi_shot();
75
76 register_trace_console(probe_console, NULL);
77 return 0;
78 }
79
kasan_suite_exit(struct kunit_suite * suite)80 static void kasan_suite_exit(struct kunit_suite *suite)
81 {
82 kasan_kunit_test_suite_end();
83 kasan_restore_multi_shot(multishot);
84 unregister_trace_console(probe_console, NULL);
85 tracepoint_synchronize_unregister();
86 }
87
kasan_test_exit(struct kunit * test)88 static void kasan_test_exit(struct kunit *test)
89 {
90 KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found));
91 }
92
93 /**
94 * KUNIT_EXPECT_KASAN_FAIL() - check that the executed expression produces a
95 * KASAN report; causes a test failure otherwise. This relies on a KUnit
96 * resource named "kasan_status". Do not use this name for KUnit resources
97 * outside of KASAN tests.
98 *
99 * For hardware tag-based KASAN, when a synchronous tag fault happens, tag
100 * checking is auto-disabled. When this happens, this test handler reenables
101 * tag checking. As tag checking can be only disabled or enabled per CPU,
102 * this handler disables migration (preemption).
103 *
104 * Since the compiler doesn't see that the expression can change the test_status
105 * fields, it can reorder or optimize away the accesses to those fields.
106 * Use READ/WRITE_ONCE() for the accesses and compiler barriers around the
107 * expression to prevent that.
108 *
109 * In between KUNIT_EXPECT_KASAN_FAIL checks, test_status.report_found is kept
110 * as false. This allows detecting KASAN reports that happen outside of the
111 * checks by asserting !test_status.report_found at the start of
112 * KUNIT_EXPECT_KASAN_FAIL and in kasan_test_exit.
113 */
114 #define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \
115 if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && \
116 kasan_sync_fault_possible()) \
117 migrate_disable(); \
118 KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found)); \
119 barrier(); \
120 expression; \
121 barrier(); \
122 if (kasan_async_fault_possible()) \
123 kasan_force_async_fault(); \
124 if (!READ_ONCE(test_status.report_found)) { \
125 KUNIT_FAIL(test, KUNIT_SUBTEST_INDENT "KASAN failure " \
126 "expected in \"" #expression \
127 "\", but none occurred"); \
128 } \
129 if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && \
130 kasan_sync_fault_possible()) { \
131 if (READ_ONCE(test_status.report_found) && \
132 !READ_ONCE(test_status.async_fault)) \
133 kasan_enable_hw_tags(); \
134 migrate_enable(); \
135 } \
136 WRITE_ONCE(test_status.report_found, false); \
137 WRITE_ONCE(test_status.async_fault, false); \
138 } while (0)
139
140 #define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do { \
141 if (!IS_ENABLED(config)) \
142 kunit_skip((test), "Test requires " #config "=y"); \
143 } while (0)
144
145 #define KASAN_TEST_NEEDS_CONFIG_OFF(test, config) do { \
146 if (IS_ENABLED(config)) \
147 kunit_skip((test), "Test requires " #config "=n"); \
148 } while (0)
149
150 #define KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test) do { \
151 if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) \
152 break; /* No compiler instrumentation. */ \
153 if (IS_ENABLED(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX)) \
154 break; /* Should always be instrumented! */ \
155 if (IS_ENABLED(CONFIG_GENERIC_ENTRY)) \
156 kunit_skip((test), "Test requires checked mem*()"); \
157 } while (0)
158
kmalloc_oob_right(struct kunit * test)159 static void kmalloc_oob_right(struct kunit *test)
160 {
161 char *ptr;
162 size_t size = 128 - KASAN_GRANULE_SIZE - 5;
163
164 ptr = kmalloc(size, GFP_KERNEL);
165 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
166
167 OPTIMIZER_HIDE_VAR(ptr);
168 /*
169 * An unaligned access past the requested kmalloc size.
170 * Only generic KASAN can precisely detect these.
171 */
172 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
173 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x');
174
175 /*
176 * An aligned access into the first out-of-bounds granule that falls
177 * within the aligned kmalloc object.
178 */
179 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + 5] = 'y');
180
181 /* Out-of-bounds access past the aligned kmalloc object. */
182 KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] =
183 ptr[size + KASAN_GRANULE_SIZE + 5]);
184
185 kfree(ptr);
186 }
187
kmalloc_oob_left(struct kunit * test)188 static void kmalloc_oob_left(struct kunit *test)
189 {
190 char *ptr;
191 size_t size = 15;
192
193 ptr = kmalloc(size, GFP_KERNEL);
194 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
195
196 OPTIMIZER_HIDE_VAR(ptr);
197 KUNIT_EXPECT_KASAN_FAIL(test, *ptr = *(ptr - 1));
198 kfree(ptr);
199 }
200
kmalloc_node_oob_right(struct kunit * test)201 static void kmalloc_node_oob_right(struct kunit *test)
202 {
203 char *ptr;
204 size_t size = 4096;
205
206 ptr = kmalloc_node(size, GFP_KERNEL, 0);
207 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
208
209 OPTIMIZER_HIDE_VAR(ptr);
210 KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
211 kfree(ptr);
212 }
213
214 /*
215 * These kmalloc_pagealloc_* tests try allocating a memory chunk that doesn't
216 * fit into a slab cache and therefore is allocated via the page allocator
217 * fallback. Since this kind of fallback is only implemented for SLUB, these
218 * tests are limited to that allocator.
219 */
kmalloc_pagealloc_oob_right(struct kunit * test)220 static void kmalloc_pagealloc_oob_right(struct kunit *test)
221 {
222 char *ptr;
223 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
224
225 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
226
227 ptr = kmalloc(size, GFP_KERNEL);
228 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
229
230 OPTIMIZER_HIDE_VAR(ptr);
231 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0);
232
233 kfree(ptr);
234 }
235
kmalloc_pagealloc_uaf(struct kunit * test)236 static void kmalloc_pagealloc_uaf(struct kunit *test)
237 {
238 char *ptr;
239 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
240
241 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
242
243 ptr = kmalloc(size, GFP_KERNEL);
244 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
245 kfree(ptr);
246
247 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
248 }
249
kmalloc_pagealloc_invalid_free(struct kunit * test)250 static void kmalloc_pagealloc_invalid_free(struct kunit *test)
251 {
252 char *ptr;
253 size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
254
255 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
256
257 ptr = kmalloc(size, GFP_KERNEL);
258 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
259
260 KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
261 }
262
pagealloc_oob_right(struct kunit * test)263 static void pagealloc_oob_right(struct kunit *test)
264 {
265 char *ptr;
266 struct page *pages;
267 size_t order = 4;
268 size_t size = (1UL << (PAGE_SHIFT + order));
269
270 /*
271 * With generic KASAN page allocations have no redzones, thus
272 * out-of-bounds detection is not guaranteed.
273 * See https://bugzilla.kernel.org/show_bug.cgi?id=210503.
274 */
275 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
276
277 pages = alloc_pages(GFP_KERNEL, order);
278 ptr = page_address(pages);
279 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
280
281 KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
282 free_pages((unsigned long)ptr, order);
283 }
284
pagealloc_uaf(struct kunit * test)285 static void pagealloc_uaf(struct kunit *test)
286 {
287 char *ptr;
288 struct page *pages;
289 size_t order = 4;
290
291 pages = alloc_pages(GFP_KERNEL, order);
292 ptr = page_address(pages);
293 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
294 free_pages((unsigned long)ptr, order);
295
296 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
297 }
298
kmalloc_large_oob_right(struct kunit * test)299 static void kmalloc_large_oob_right(struct kunit *test)
300 {
301 char *ptr;
302 size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
303
304 /*
305 * Allocate a chunk that is large enough, but still fits into a slab
306 * and does not trigger the page allocator fallback in SLUB.
307 */
308 ptr = kmalloc(size, GFP_KERNEL);
309 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
310
311 OPTIMIZER_HIDE_VAR(ptr);
312 KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
313 kfree(ptr);
314 }
315
krealloc_more_oob_helper(struct kunit * test,size_t size1,size_t size2)316 static void krealloc_more_oob_helper(struct kunit *test,
317 size_t size1, size_t size2)
318 {
319 char *ptr1, *ptr2;
320 size_t middle;
321
322 KUNIT_ASSERT_LT(test, size1, size2);
323 middle = size1 + (size2 - size1) / 2;
324
325 ptr1 = kmalloc(size1, GFP_KERNEL);
326 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
327
328 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
329 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
330
331 /* Suppress -Warray-bounds warnings. */
332 OPTIMIZER_HIDE_VAR(ptr2);
333
334 /* All offsets up to size2 must be accessible. */
335 ptr2[size1 - 1] = 'x';
336 ptr2[size1] = 'x';
337 ptr2[middle] = 'x';
338 ptr2[size2 - 1] = 'x';
339
340 /* Generic mode is precise, so unaligned size2 must be inaccessible. */
341 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
342 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
343
344 /* For all modes first aligned offset after size2 must be inaccessible. */
345 KUNIT_EXPECT_KASAN_FAIL(test,
346 ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x');
347
348 kfree(ptr2);
349 }
350
krealloc_less_oob_helper(struct kunit * test,size_t size1,size_t size2)351 static void krealloc_less_oob_helper(struct kunit *test,
352 size_t size1, size_t size2)
353 {
354 char *ptr1, *ptr2;
355 size_t middle;
356
357 KUNIT_ASSERT_LT(test, size2, size1);
358 middle = size2 + (size1 - size2) / 2;
359
360 ptr1 = kmalloc(size1, GFP_KERNEL);
361 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
362
363 ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
364 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
365
366 /* Suppress -Warray-bounds warnings. */
367 OPTIMIZER_HIDE_VAR(ptr2);
368
369 /* Must be accessible for all modes. */
370 ptr2[size2 - 1] = 'x';
371
372 /* Generic mode is precise, so unaligned size2 must be inaccessible. */
373 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
374 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
375
376 /* For all modes first aligned offset after size2 must be inaccessible. */
377 KUNIT_EXPECT_KASAN_FAIL(test,
378 ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x');
379
380 /*
381 * For all modes all size2, middle, and size1 should land in separate
382 * granules and thus the latter two offsets should be inaccessible.
383 */
384 KUNIT_EXPECT_LE(test, round_up(size2, KASAN_GRANULE_SIZE),
385 round_down(middle, KASAN_GRANULE_SIZE));
386 KUNIT_EXPECT_LE(test, round_up(middle, KASAN_GRANULE_SIZE),
387 round_down(size1, KASAN_GRANULE_SIZE));
388 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[middle] = 'x');
389 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1 - 1] = 'x');
390 KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1] = 'x');
391
392 kfree(ptr2);
393 }
394
krealloc_more_oob(struct kunit * test)395 static void krealloc_more_oob(struct kunit *test)
396 {
397 krealloc_more_oob_helper(test, 201, 235);
398 }
399
krealloc_less_oob(struct kunit * test)400 static void krealloc_less_oob(struct kunit *test)
401 {
402 krealloc_less_oob_helper(test, 235, 201);
403 }
404
krealloc_pagealloc_more_oob(struct kunit * test)405 static void krealloc_pagealloc_more_oob(struct kunit *test)
406 {
407 /* page_alloc fallback in only implemented for SLUB. */
408 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
409
410 krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201,
411 KMALLOC_MAX_CACHE_SIZE + 235);
412 }
413
krealloc_pagealloc_less_oob(struct kunit * test)414 static void krealloc_pagealloc_less_oob(struct kunit *test)
415 {
416 /* page_alloc fallback in only implemented for SLUB. */
417 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
418
419 krealloc_less_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 235,
420 KMALLOC_MAX_CACHE_SIZE + 201);
421 }
422
423 /*
424 * Check that krealloc() detects a use-after-free, returns NULL,
425 * and doesn't unpoison the freed object.
426 */
krealloc_uaf(struct kunit * test)427 static void krealloc_uaf(struct kunit *test)
428 {
429 char *ptr1, *ptr2;
430 int size1 = 201;
431 int size2 = 235;
432
433 ptr1 = kmalloc(size1, GFP_KERNEL);
434 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
435 kfree(ptr1);
436
437 KUNIT_EXPECT_KASAN_FAIL(test, ptr2 = krealloc(ptr1, size2, GFP_KERNEL));
438 KUNIT_ASSERT_NULL(test, ptr2);
439 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)ptr1);
440 }
441
kmalloc_oob_16(struct kunit * test)442 static void kmalloc_oob_16(struct kunit *test)
443 {
444 struct {
445 u64 words[2];
446 } *ptr1, *ptr2;
447
448 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
449
450 /* This test is specifically crafted for the generic mode. */
451 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
452
453 /* RELOC_HIDE to prevent gcc from warning about short alloc */
454 ptr1 = RELOC_HIDE(kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL), 0);
455 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
456
457 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
458 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
459
460 OPTIMIZER_HIDE_VAR(ptr1);
461 OPTIMIZER_HIDE_VAR(ptr2);
462 KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
463 kfree(ptr1);
464 kfree(ptr2);
465 }
466
kmalloc_uaf_16(struct kunit * test)467 static void kmalloc_uaf_16(struct kunit *test)
468 {
469 struct {
470 u64 words[2];
471 } *ptr1, *ptr2;
472
473 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
474
475 ptr1 = kmalloc(sizeof(*ptr1), GFP_KERNEL);
476 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
477
478 ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
479 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
480 kfree(ptr2);
481
482 KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
483 kfree(ptr1);
484 }
485
486 /*
487 * Note: in the memset tests below, the written range touches both valid and
488 * invalid memory. This makes sure that the instrumentation does not only check
489 * the starting address but the whole range.
490 */
491
kmalloc_oob_memset_2(struct kunit * test)492 static void kmalloc_oob_memset_2(struct kunit *test)
493 {
494 char *ptr;
495 size_t size = 128 - KASAN_GRANULE_SIZE;
496
497 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
498
499 ptr = kmalloc(size, GFP_KERNEL);
500 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
501
502 OPTIMIZER_HIDE_VAR(size);
503 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, 2));
504 kfree(ptr);
505 }
506
kmalloc_oob_memset_4(struct kunit * test)507 static void kmalloc_oob_memset_4(struct kunit *test)
508 {
509 char *ptr;
510 size_t size = 128 - KASAN_GRANULE_SIZE;
511
512 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
513
514 ptr = kmalloc(size, GFP_KERNEL);
515 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
516
517 OPTIMIZER_HIDE_VAR(size);
518 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, 4));
519 kfree(ptr);
520 }
521
kmalloc_oob_memset_8(struct kunit * test)522 static void kmalloc_oob_memset_8(struct kunit *test)
523 {
524 char *ptr;
525 size_t size = 128 - KASAN_GRANULE_SIZE;
526
527 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
528
529 ptr = kmalloc(size, GFP_KERNEL);
530 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
531
532 OPTIMIZER_HIDE_VAR(size);
533 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, 8));
534 kfree(ptr);
535 }
536
kmalloc_oob_memset_16(struct kunit * test)537 static void kmalloc_oob_memset_16(struct kunit *test)
538 {
539 char *ptr;
540 size_t size = 128 - KASAN_GRANULE_SIZE;
541
542 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
543
544 ptr = kmalloc(size, GFP_KERNEL);
545 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
546
547 OPTIMIZER_HIDE_VAR(size);
548 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, 16));
549 kfree(ptr);
550 }
551
kmalloc_oob_in_memset(struct kunit * test)552 static void kmalloc_oob_in_memset(struct kunit *test)
553 {
554 char *ptr;
555 size_t size = 128 - KASAN_GRANULE_SIZE;
556
557 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
558
559 ptr = kmalloc(size, GFP_KERNEL);
560 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
561
562 OPTIMIZER_HIDE_VAR(ptr);
563 OPTIMIZER_HIDE_VAR(size);
564 KUNIT_EXPECT_KASAN_FAIL(test,
565 memset(ptr, 0, size + KASAN_GRANULE_SIZE));
566 kfree(ptr);
567 }
568
kmalloc_memmove_negative_size(struct kunit * test)569 static void kmalloc_memmove_negative_size(struct kunit *test)
570 {
571 char *ptr;
572 size_t size = 64;
573 size_t invalid_size = -2;
574
575 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
576
577 /*
578 * Hardware tag-based mode doesn't check memmove for negative size.
579 * As a result, this test introduces a side-effect memory corruption,
580 * which can result in a crash.
581 */
582 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);
583
584 ptr = kmalloc(size, GFP_KERNEL);
585 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
586
587 memset((char *)ptr, 0, 64);
588 OPTIMIZER_HIDE_VAR(ptr);
589 OPTIMIZER_HIDE_VAR(invalid_size);
590 KUNIT_EXPECT_KASAN_FAIL(test,
591 memmove((char *)ptr, (char *)ptr + 4, invalid_size));
592 kfree(ptr);
593 }
594
kmalloc_memmove_invalid_size(struct kunit * test)595 static void kmalloc_memmove_invalid_size(struct kunit *test)
596 {
597 char *ptr;
598 size_t size = 64;
599 size_t invalid_size = size;
600
601 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
602
603 ptr = kmalloc(size, GFP_KERNEL);
604 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
605
606 memset((char *)ptr, 0, 64);
607 OPTIMIZER_HIDE_VAR(ptr);
608 OPTIMIZER_HIDE_VAR(invalid_size);
609 KUNIT_EXPECT_KASAN_FAIL(test,
610 memmove((char *)ptr, (char *)ptr + 4, invalid_size));
611 kfree(ptr);
612 }
613
kmalloc_uaf(struct kunit * test)614 static void kmalloc_uaf(struct kunit *test)
615 {
616 char *ptr;
617 size_t size = 10;
618
619 ptr = kmalloc(size, GFP_KERNEL);
620 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
621
622 kfree(ptr);
623 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[8]);
624 }
625
kmalloc_uaf_memset(struct kunit * test)626 static void kmalloc_uaf_memset(struct kunit *test)
627 {
628 char *ptr;
629 size_t size = 33;
630
631 KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);
632
633 /*
634 * Only generic KASAN uses quarantine, which is required to avoid a
635 * kernel memory corruption this test causes.
636 */
637 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
638
639 ptr = kmalloc(size, GFP_KERNEL);
640 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
641
642 kfree(ptr);
643 KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size));
644 }
645
kmalloc_uaf2(struct kunit * test)646 static void kmalloc_uaf2(struct kunit *test)
647 {
648 char *ptr1, *ptr2;
649 size_t size = 43;
650 int counter = 0;
651
652 again:
653 ptr1 = kmalloc(size, GFP_KERNEL);
654 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
655
656 kfree(ptr1);
657
658 ptr2 = kmalloc(size, GFP_KERNEL);
659 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
660
661 /*
662 * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same.
663 * Allow up to 16 attempts at generating different tags.
664 */
665 if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 16) {
666 kfree(ptr2);
667 goto again;
668 }
669
670 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[40]);
671 KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
672
673 kfree(ptr2);
674 }
675
676 /*
677 * Check that KASAN detects use-after-free when another object was allocated in
678 * the same slot. Relevant for the tag-based modes, which do not use quarantine.
679 */
kmalloc_uaf3(struct kunit * test)680 static void kmalloc_uaf3(struct kunit *test)
681 {
682 char *ptr1, *ptr2;
683 size_t size = 100;
684
685 /* This test is specifically crafted for tag-based modes. */
686 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
687
688 ptr1 = kmalloc(size, GFP_KERNEL);
689 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
690 kfree(ptr1);
691
692 ptr2 = kmalloc(size, GFP_KERNEL);
693 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
694 kfree(ptr2);
695
696 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[8]);
697 }
698
kfree_via_page(struct kunit * test)699 static void kfree_via_page(struct kunit *test)
700 {
701 char *ptr;
702 size_t size = 8;
703 struct page *page;
704 unsigned long offset;
705
706 ptr = kmalloc(size, GFP_KERNEL);
707 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
708
709 page = virt_to_page(ptr);
710 offset = offset_in_page(ptr);
711 kfree(page_address(page) + offset);
712 }
713
kfree_via_phys(struct kunit * test)714 static void kfree_via_phys(struct kunit *test)
715 {
716 char *ptr;
717 size_t size = 8;
718 phys_addr_t phys;
719
720 ptr = kmalloc(size, GFP_KERNEL);
721 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
722
723 phys = virt_to_phys(ptr);
724 kfree(phys_to_virt(phys));
725 }
726
kmem_cache_oob(struct kunit * test)727 static void kmem_cache_oob(struct kunit *test)
728 {
729 char *p;
730 size_t size = 200;
731 struct kmem_cache *cache;
732
733 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
734 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
735
736 p = kmem_cache_alloc(cache, GFP_KERNEL);
737 if (!p) {
738 kunit_err(test, "Allocation failed: %s\n", __func__);
739 kmem_cache_destroy(cache);
740 return;
741 }
742
743 KUNIT_EXPECT_KASAN_FAIL(test, *p = p[size + OOB_TAG_OFF]);
744
745 kmem_cache_free(cache, p);
746 kmem_cache_destroy(cache);
747 }
748
kmem_cache_accounted(struct kunit * test)749 static void kmem_cache_accounted(struct kunit *test)
750 {
751 int i;
752 char *p;
753 size_t size = 200;
754 struct kmem_cache *cache;
755
756 cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
757 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
758
759 /*
760 * Several allocations with a delay to allow for lazy per memcg kmem
761 * cache creation.
762 */
763 for (i = 0; i < 5; i++) {
764 p = kmem_cache_alloc(cache, GFP_KERNEL);
765 if (!p)
766 goto free_cache;
767
768 kmem_cache_free(cache, p);
769 msleep(100);
770 }
771
772 free_cache:
773 kmem_cache_destroy(cache);
774 }
775
kmem_cache_bulk(struct kunit * test)776 static void kmem_cache_bulk(struct kunit *test)
777 {
778 struct kmem_cache *cache;
779 size_t size = 200;
780 char *p[10];
781 bool ret;
782 int i;
783
784 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
785 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
786
787 ret = kmem_cache_alloc_bulk(cache, GFP_KERNEL, ARRAY_SIZE(p), (void **)&p);
788 if (!ret) {
789 kunit_err(test, "Allocation failed: %s\n", __func__);
790 kmem_cache_destroy(cache);
791 return;
792 }
793
794 for (i = 0; i < ARRAY_SIZE(p); i++)
795 p[i][0] = p[i][size - 1] = 42;
796
797 kmem_cache_free_bulk(cache, ARRAY_SIZE(p), (void **)&p);
798 kmem_cache_destroy(cache);
799 }
800
801 static char global_array[10];
802
kasan_global_oob_right(struct kunit * test)803 static void kasan_global_oob_right(struct kunit *test)
804 {
805 /*
806 * Deliberate out-of-bounds access. To prevent CONFIG_UBSAN_LOCAL_BOUNDS
807 * from failing here and panicking the kernel, access the array via a
808 * volatile pointer, which will prevent the compiler from being able to
809 * determine the array bounds.
810 *
811 * This access uses a volatile pointer to char (char *volatile) rather
812 * than the more conventional pointer to volatile char (volatile char *)
813 * because we want to prevent the compiler from making inferences about
814 * the pointer itself (i.e. its array bounds), not the data that it
815 * refers to.
816 */
817 char *volatile array = global_array;
818 char *p = &array[ARRAY_SIZE(global_array) + 3];
819
820 /* Only generic mode instruments globals. */
821 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
822
823 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
824 }
825
kasan_global_oob_left(struct kunit * test)826 static void kasan_global_oob_left(struct kunit *test)
827 {
828 char *volatile array = global_array;
829 char *p = array - 3;
830
831 /*
832 * GCC is known to fail this test, skip it.
833 * See https://bugzilla.kernel.org/show_bug.cgi?id=215051.
834 */
835 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_CC_IS_CLANG);
836 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
837 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
838 }
839
840 /* Check that ksize() does NOT unpoison whole object. */
ksize_unpoisons_memory(struct kunit * test)841 static void ksize_unpoisons_memory(struct kunit *test)
842 {
843 char *ptr;
844 size_t size = 128 - KASAN_GRANULE_SIZE - 5;
845 size_t real_size;
846
847 ptr = kmalloc(size, GFP_KERNEL);
848 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
849
850 real_size = ksize(ptr);
851 KUNIT_EXPECT_GT(test, real_size, size);
852
853 OPTIMIZER_HIDE_VAR(ptr);
854
855 /* These accesses shouldn't trigger a KASAN report. */
856 ptr[0] = 'x';
857 ptr[size - 1] = 'x';
858
859 /* These must trigger a KASAN report. */
860 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
861 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
862 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size + 5]);
863 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size - 1]);
864
865 kfree(ptr);
866 }
867
868 /*
869 * Check that a use-after-free is detected by ksize() and via normal accesses
870 * after it.
871 */
ksize_uaf(struct kunit * test)872 static void ksize_uaf(struct kunit *test)
873 {
874 char *ptr;
875 int size = 128 - KASAN_GRANULE_SIZE;
876
877 ptr = kmalloc(size, GFP_KERNEL);
878 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
879 kfree(ptr);
880
881 OPTIMIZER_HIDE_VAR(ptr);
882 KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
883 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
884 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
885 }
886
kasan_stack_oob(struct kunit * test)887 static void kasan_stack_oob(struct kunit *test)
888 {
889 char stack_array[10];
890 /* See comment in kasan_global_oob_right. */
891 char *volatile array = stack_array;
892 char *p = &array[ARRAY_SIZE(stack_array) + OOB_TAG_OFF];
893
894 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
895
896 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
897 }
898
kasan_alloca_oob_left(struct kunit * test)899 static void kasan_alloca_oob_left(struct kunit *test)
900 {
901 volatile int i = 10;
902 char alloca_array[i];
903 /* See comment in kasan_global_oob_right. */
904 char *volatile array = alloca_array;
905 char *p = array - 1;
906
907 /* Only generic mode instruments dynamic allocas. */
908 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
909 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
910
911 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
912 }
913
kasan_alloca_oob_right(struct kunit * test)914 static void kasan_alloca_oob_right(struct kunit *test)
915 {
916 volatile int i = 10;
917 char alloca_array[i];
918 /* See comment in kasan_global_oob_right. */
919 char *volatile array = alloca_array;
920 char *p = array + i;
921
922 /* Only generic mode instruments dynamic allocas. */
923 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
924 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);
925
926 KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
927 }
928
kmem_cache_double_free(struct kunit * test)929 static void kmem_cache_double_free(struct kunit *test)
930 {
931 char *p;
932 size_t size = 200;
933 struct kmem_cache *cache;
934
935 cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
936 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
937
938 p = kmem_cache_alloc(cache, GFP_KERNEL);
939 if (!p) {
940 kunit_err(test, "Allocation failed: %s\n", __func__);
941 kmem_cache_destroy(cache);
942 return;
943 }
944
945 kmem_cache_free(cache, p);
946 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p));
947 kmem_cache_destroy(cache);
948 }
949
kmem_cache_invalid_free(struct kunit * test)950 static void kmem_cache_invalid_free(struct kunit *test)
951 {
952 char *p;
953 size_t size = 200;
954 struct kmem_cache *cache;
955
956 cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
957 NULL);
958 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
959
960 p = kmem_cache_alloc(cache, GFP_KERNEL);
961 if (!p) {
962 kunit_err(test, "Allocation failed: %s\n", __func__);
963 kmem_cache_destroy(cache);
964 return;
965 }
966
967 /* Trigger invalid free, the object doesn't get freed. */
968 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));
969
970 /*
971 * Properly free the object to prevent the "Objects remaining in
972 * test_cache on __kmem_cache_shutdown" BUG failure.
973 */
974 kmem_cache_free(cache, p);
975
976 kmem_cache_destroy(cache);
977 }
978
empty_cache_ctor(void * object)979 static void empty_cache_ctor(void *object) { }
980
kmem_cache_double_destroy(struct kunit * test)981 static void kmem_cache_double_destroy(struct kunit *test)
982 {
983 struct kmem_cache *cache;
984
985 /* Provide a constructor to prevent cache merging. */
986 cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor);
987 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
988 kmem_cache_destroy(cache);
989 KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache));
990 }
991
kasan_memchr(struct kunit * test)992 static void kasan_memchr(struct kunit *test)
993 {
994 char *ptr;
995 size_t size = 24;
996
997 /*
998 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
999 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
1000 */
1001 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
1002
1003 if (OOB_TAG_OFF)
1004 size = round_up(size, OOB_TAG_OFF);
1005
1006 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
1007 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1008
1009 OPTIMIZER_HIDE_VAR(ptr);
1010 OPTIMIZER_HIDE_VAR(size);
1011 KUNIT_EXPECT_KASAN_FAIL(test,
1012 kasan_ptr_result = memchr(ptr, '1', size + 1));
1013
1014 kfree(ptr);
1015 }
1016
kasan_memcmp(struct kunit * test)1017 static void kasan_memcmp(struct kunit *test)
1018 {
1019 char *ptr;
1020 size_t size = 24;
1021 int arr[9];
1022
1023 /*
1024 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
1025 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
1026 */
1027 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
1028
1029 if (OOB_TAG_OFF)
1030 size = round_up(size, OOB_TAG_OFF);
1031
1032 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
1033 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1034 memset(arr, 0, sizeof(arr));
1035
1036 OPTIMIZER_HIDE_VAR(ptr);
1037 OPTIMIZER_HIDE_VAR(size);
1038 KUNIT_EXPECT_KASAN_FAIL(test,
1039 kasan_int_result = memcmp(ptr, arr, size+1));
1040 kfree(ptr);
1041 }
1042
kasan_strings(struct kunit * test)1043 static void kasan_strings(struct kunit *test)
1044 {
1045 char *ptr;
1046 size_t size = 24;
1047
1048 /*
1049 * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
1050 * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
1051 */
1052 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);
1053
1054 ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
1055 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1056
1057 kfree(ptr);
1058
1059 /*
1060 * Try to cause only 1 invalid access (less spam in dmesg).
1061 * For that we need ptr to point to zeroed byte.
1062 * Skip metadata that could be stored in freed object so ptr
1063 * will likely point to zeroed byte.
1064 */
1065 ptr += 16;
1066 KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strchr(ptr, '1'));
1067
1068 KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strrchr(ptr, '1'));
1069
1070 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strcmp(ptr, "2"));
1071
1072 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strncmp(ptr, "2", 1));
1073
1074 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strlen(ptr));
1075
1076 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strnlen(ptr, 1));
1077 }
1078
kasan_bitops_modify(struct kunit * test,int nr,void * addr)1079 static void kasan_bitops_modify(struct kunit *test, int nr, void *addr)
1080 {
1081 KUNIT_EXPECT_KASAN_FAIL(test, set_bit(nr, addr));
1082 KUNIT_EXPECT_KASAN_FAIL(test, __set_bit(nr, addr));
1083 KUNIT_EXPECT_KASAN_FAIL(test, clear_bit(nr, addr));
1084 KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit(nr, addr));
1085 KUNIT_EXPECT_KASAN_FAIL(test, clear_bit_unlock(nr, addr));
1086 KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit_unlock(nr, addr));
1087 KUNIT_EXPECT_KASAN_FAIL(test, change_bit(nr, addr));
1088 KUNIT_EXPECT_KASAN_FAIL(test, __change_bit(nr, addr));
1089 }
1090
kasan_bitops_test_and_modify(struct kunit * test,int nr,void * addr)1091 static void kasan_bitops_test_and_modify(struct kunit *test, int nr, void *addr)
1092 {
1093 KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit(nr, addr));
1094 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_set_bit(nr, addr));
1095 KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit_lock(nr, addr));
1096 KUNIT_EXPECT_KASAN_FAIL(test, test_and_clear_bit(nr, addr));
1097 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_clear_bit(nr, addr));
1098 KUNIT_EXPECT_KASAN_FAIL(test, test_and_change_bit(nr, addr));
1099 KUNIT_EXPECT_KASAN_FAIL(test, __test_and_change_bit(nr, addr));
1100 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = test_bit(nr, addr));
1101
1102 #if defined(clear_bit_unlock_is_negative_byte)
1103 KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result =
1104 clear_bit_unlock_is_negative_byte(nr, addr));
1105 #endif
1106 }
1107
kasan_bitops_generic(struct kunit * test)1108 static void kasan_bitops_generic(struct kunit *test)
1109 {
1110 long *bits;
1111
1112 /* This test is specifically crafted for the generic mode. */
1113 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
1114
1115 /*
1116 * Allocate 1 more byte, which causes kzalloc to round up to 16 bytes;
1117 * this way we do not actually corrupt other memory.
1118 */
1119 bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL);
1120 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
1121
1122 /*
1123 * Below calls try to access bit within allocated memory; however, the
1124 * below accesses are still out-of-bounds, since bitops are defined to
1125 * operate on the whole long the bit is in.
1126 */
1127 kasan_bitops_modify(test, BITS_PER_LONG, bits);
1128
1129 /*
1130 * Below calls try to access bit beyond allocated memory.
1131 */
1132 kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, bits);
1133
1134 kfree(bits);
1135 }
1136
kasan_bitops_tags(struct kunit * test)1137 static void kasan_bitops_tags(struct kunit *test)
1138 {
1139 long *bits;
1140
1141 /* This test is specifically crafted for tag-based modes. */
1142 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1143
1144 /* kmalloc-64 cache will be used and the last 16 bytes will be the redzone. */
1145 bits = kzalloc(48, GFP_KERNEL);
1146 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
1147
1148 /* Do the accesses past the 48 allocated bytes, but within the redone. */
1149 kasan_bitops_modify(test, BITS_PER_LONG, (void *)bits + 48);
1150 kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, (void *)bits + 48);
1151
1152 kfree(bits);
1153 }
1154
kmalloc_double_kzfree(struct kunit * test)1155 static void kmalloc_double_kzfree(struct kunit *test)
1156 {
1157 char *ptr;
1158 size_t size = 16;
1159
1160 ptr = kmalloc(size, GFP_KERNEL);
1161 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1162
1163 kfree_sensitive(ptr);
1164 KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr));
1165 }
1166
1167 /*
1168 * The two tests below check that Generic KASAN prints auxiliary stack traces
1169 * for RCU callbacks and workqueues. The reports need to be inspected manually.
1170 *
1171 * These tests are still enabled for other KASAN modes to make sure that all
1172 * modes report bad accesses in tested scenarios.
1173 */
1174
1175 static struct kasan_rcu_info {
1176 int i;
1177 struct rcu_head rcu;
1178 } *global_rcu_ptr;
1179
rcu_uaf_reclaim(struct rcu_head * rp)1180 static void rcu_uaf_reclaim(struct rcu_head *rp)
1181 {
1182 struct kasan_rcu_info *fp =
1183 container_of(rp, struct kasan_rcu_info, rcu);
1184
1185 kfree(fp);
1186 ((volatile struct kasan_rcu_info *)fp)->i;
1187 }
1188
rcu_uaf(struct kunit * test)1189 static void rcu_uaf(struct kunit *test)
1190 {
1191 struct kasan_rcu_info *ptr;
1192
1193 ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
1194 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1195
1196 global_rcu_ptr = rcu_dereference_protected(
1197 (struct kasan_rcu_info __rcu *)ptr, NULL);
1198
1199 KUNIT_EXPECT_KASAN_FAIL(test,
1200 call_rcu(&global_rcu_ptr->rcu, rcu_uaf_reclaim);
1201 rcu_barrier());
1202 }
1203
workqueue_uaf_work(struct work_struct * work)1204 static void workqueue_uaf_work(struct work_struct *work)
1205 {
1206 kfree(work);
1207 }
1208
workqueue_uaf(struct kunit * test)1209 static void workqueue_uaf(struct kunit *test)
1210 {
1211 struct workqueue_struct *workqueue;
1212 struct work_struct *work;
1213
1214 workqueue = create_workqueue("kasan_workqueue_test");
1215 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, workqueue);
1216
1217 work = kmalloc(sizeof(struct work_struct), GFP_KERNEL);
1218 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, work);
1219
1220 INIT_WORK(work, workqueue_uaf_work);
1221 queue_work(workqueue, work);
1222 destroy_workqueue(workqueue);
1223
1224 KUNIT_EXPECT_KASAN_FAIL(test,
1225 ((volatile struct work_struct *)work)->data);
1226 }
1227
vmalloc_helpers_tags(struct kunit * test)1228 static void vmalloc_helpers_tags(struct kunit *test)
1229 {
1230 void *ptr;
1231
1232 /* This test is intended for tag-based modes. */
1233 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1234
1235 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1236
1237 ptr = vmalloc(PAGE_SIZE);
1238 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1239
1240 /* Check that the returned pointer is tagged. */
1241 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1242 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1243
1244 /* Make sure exported vmalloc helpers handle tagged pointers. */
1245 KUNIT_ASSERT_TRUE(test, is_vmalloc_addr(ptr));
1246 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vmalloc_to_page(ptr));
1247
1248 #if !IS_MODULE(CONFIG_KASAN_KUNIT_TEST)
1249 {
1250 int rv;
1251
1252 /* Make sure vmalloc'ed memory permissions can be changed. */
1253 rv = set_memory_ro((unsigned long)ptr, 1);
1254 KUNIT_ASSERT_GE(test, rv, 0);
1255 rv = set_memory_rw((unsigned long)ptr, 1);
1256 KUNIT_ASSERT_GE(test, rv, 0);
1257 }
1258 #endif
1259
1260 vfree(ptr);
1261 }
1262
vmalloc_oob(struct kunit * test)1263 static void vmalloc_oob(struct kunit *test)
1264 {
1265 char *v_ptr, *p_ptr;
1266 struct page *page;
1267 size_t size = PAGE_SIZE / 2 - KASAN_GRANULE_SIZE - 5;
1268
1269 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1270
1271 v_ptr = vmalloc(size);
1272 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1273
1274 OPTIMIZER_HIDE_VAR(v_ptr);
1275
1276 /*
1277 * We have to be careful not to hit the guard page in vmalloc tests.
1278 * The MMU will catch that and crash us.
1279 */
1280
1281 /* Make sure in-bounds accesses are valid. */
1282 v_ptr[0] = 0;
1283 v_ptr[size - 1] = 0;
1284
1285 /*
1286 * An unaligned access past the requested vmalloc size.
1287 * Only generic KASAN can precisely detect these.
1288 */
1289 if (IS_ENABLED(CONFIG_KASAN_GENERIC))
1290 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size]);
1291
1292 /* An aligned access into the first out-of-bounds granule. */
1293 KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size + 5]);
1294
1295 /* Check that in-bounds accesses to the physical page are valid. */
1296 page = vmalloc_to_page(v_ptr);
1297 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
1298 p_ptr = page_address(page);
1299 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1300 p_ptr[0] = 0;
1301
1302 vfree(v_ptr);
1303
1304 /*
1305 * We can't check for use-after-unmap bugs in this nor in the following
1306 * vmalloc tests, as the page might be fully unmapped and accessing it
1307 * will crash the kernel.
1308 */
1309 }
1310
vmap_tags(struct kunit * test)1311 static void vmap_tags(struct kunit *test)
1312 {
1313 char *p_ptr, *v_ptr;
1314 struct page *p_page, *v_page;
1315
1316 /*
1317 * This test is specifically crafted for the software tag-based mode,
1318 * the only tag-based mode that poisons vmap mappings.
1319 */
1320 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
1321
1322 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
1323
1324 p_page = alloc_pages(GFP_KERNEL, 1);
1325 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_page);
1326 p_ptr = page_address(p_page);
1327 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1328
1329 v_ptr = vmap(&p_page, 1, VM_MAP, PAGE_KERNEL);
1330 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1331
1332 /*
1333 * We can't check for out-of-bounds bugs in this nor in the following
1334 * vmalloc tests, as allocations have page granularity and accessing
1335 * the guard page will crash the kernel.
1336 */
1337
1338 KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
1339 KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL);
1340
1341 /* Make sure that in-bounds accesses through both pointers work. */
1342 *p_ptr = 0;
1343 *v_ptr = 0;
1344
1345 /* Make sure vmalloc_to_page() correctly recovers the page pointer. */
1346 v_page = vmalloc_to_page(v_ptr);
1347 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_page);
1348 KUNIT_EXPECT_PTR_EQ(test, p_page, v_page);
1349
1350 vunmap(v_ptr);
1351 free_pages((unsigned long)p_ptr, 1);
1352 }
1353
vm_map_ram_tags(struct kunit * test)1354 static void vm_map_ram_tags(struct kunit *test)
1355 {
1356 char *p_ptr, *v_ptr;
1357 struct page *page;
1358
1359 /*
1360 * This test is specifically crafted for the software tag-based mode,
1361 * the only tag-based mode that poisons vm_map_ram mappings.
1362 */
1363 KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
1364
1365 page = alloc_pages(GFP_KERNEL, 1);
1366 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
1367 p_ptr = page_address(page);
1368 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
1369
1370 v_ptr = vm_map_ram(&page, 1, -1);
1371 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);
1372
1373 KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
1374 KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL);
1375
1376 /* Make sure that in-bounds accesses through both pointers work. */
1377 *p_ptr = 0;
1378 *v_ptr = 0;
1379
1380 vm_unmap_ram(v_ptr, 1);
1381 free_pages((unsigned long)p_ptr, 1);
1382 }
1383
1384 /*
1385 * Check that the assigned pointer tag falls within the [KASAN_TAG_MIN,
1386 * KASAN_TAG_KERNEL) range (note: excluding the match-all tag) for tag-based
1387 * modes.
1388 */
match_all_not_assigned(struct kunit * test)1389 static void match_all_not_assigned(struct kunit *test)
1390 {
1391 char *ptr;
1392 struct page *pages;
1393 int i, size, order;
1394
1395 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1396
1397 for (i = 0; i < 256; i++) {
1398 size = get_random_u32_inclusive(1, 1024);
1399 ptr = kmalloc(size, GFP_KERNEL);
1400 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1401 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1402 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1403 kfree(ptr);
1404 }
1405
1406 for (i = 0; i < 256; i++) {
1407 order = get_random_u32_inclusive(1, 4);
1408 pages = alloc_pages(GFP_KERNEL, order);
1409 ptr = page_address(pages);
1410 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1411 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1412 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1413 free_pages((unsigned long)ptr, order);
1414 }
1415
1416 if (!IS_ENABLED(CONFIG_KASAN_VMALLOC))
1417 return;
1418
1419 for (i = 0; i < 256; i++) {
1420 size = get_random_u32_inclusive(1, 1024);
1421 ptr = vmalloc(size);
1422 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1423 KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
1424 KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1425 vfree(ptr);
1426 }
1427 }
1428
1429 /* Check that 0xff works as a match-all pointer tag for tag-based modes. */
match_all_ptr_tag(struct kunit * test)1430 static void match_all_ptr_tag(struct kunit *test)
1431 {
1432 char *ptr;
1433 u8 tag;
1434
1435 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1436
1437 ptr = kmalloc(128, GFP_KERNEL);
1438 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1439
1440 /* Backup the assigned tag. */
1441 tag = get_tag(ptr);
1442 KUNIT_EXPECT_NE(test, tag, (u8)KASAN_TAG_KERNEL);
1443
1444 /* Reset the tag to 0xff.*/
1445 ptr = set_tag(ptr, KASAN_TAG_KERNEL);
1446
1447 /* This access shouldn't trigger a KASAN report. */
1448 *ptr = 0;
1449
1450 /* Recover the pointer tag and free. */
1451 ptr = set_tag(ptr, tag);
1452 kfree(ptr);
1453 }
1454
1455 /* Check that there are no match-all memory tags for tag-based modes. */
match_all_mem_tag(struct kunit * test)1456 static void match_all_mem_tag(struct kunit *test)
1457 {
1458 char *ptr;
1459 int tag;
1460
1461 KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);
1462
1463 ptr = kmalloc(128, GFP_KERNEL);
1464 KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
1465 KUNIT_EXPECT_NE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
1466
1467 /* For each possible tag value not matching the pointer tag. */
1468 for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) {
1469 if (tag == get_tag(ptr))
1470 continue;
1471
1472 /* Mark the first memory granule with the chosen memory tag. */
1473 kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag, false);
1474
1475 /* This access must cause a KASAN report. */
1476 KUNIT_EXPECT_KASAN_FAIL(test, *ptr = 0);
1477 }
1478
1479 /* Recover the memory tag and free. */
1480 kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr), false);
1481 kfree(ptr);
1482 }
1483
1484 static struct kunit_case kasan_kunit_test_cases[] = {
1485 KUNIT_CASE(kmalloc_oob_right),
1486 KUNIT_CASE(kmalloc_oob_left),
1487 KUNIT_CASE(kmalloc_node_oob_right),
1488 KUNIT_CASE(kmalloc_pagealloc_oob_right),
1489 KUNIT_CASE(kmalloc_pagealloc_uaf),
1490 KUNIT_CASE(kmalloc_pagealloc_invalid_free),
1491 KUNIT_CASE(pagealloc_oob_right),
1492 KUNIT_CASE(pagealloc_uaf),
1493 KUNIT_CASE(kmalloc_large_oob_right),
1494 KUNIT_CASE(krealloc_more_oob),
1495 KUNIT_CASE(krealloc_less_oob),
1496 KUNIT_CASE(krealloc_pagealloc_more_oob),
1497 KUNIT_CASE(krealloc_pagealloc_less_oob),
1498 KUNIT_CASE(krealloc_uaf),
1499 KUNIT_CASE(kmalloc_oob_16),
1500 KUNIT_CASE(kmalloc_uaf_16),
1501 KUNIT_CASE(kmalloc_oob_in_memset),
1502 KUNIT_CASE(kmalloc_oob_memset_2),
1503 KUNIT_CASE(kmalloc_oob_memset_4),
1504 KUNIT_CASE(kmalloc_oob_memset_8),
1505 KUNIT_CASE(kmalloc_oob_memset_16),
1506 KUNIT_CASE(kmalloc_memmove_negative_size),
1507 KUNIT_CASE(kmalloc_memmove_invalid_size),
1508 KUNIT_CASE(kmalloc_uaf),
1509 KUNIT_CASE(kmalloc_uaf_memset),
1510 KUNIT_CASE(kmalloc_uaf2),
1511 KUNIT_CASE(kmalloc_uaf3),
1512 KUNIT_CASE(kfree_via_page),
1513 KUNIT_CASE(kfree_via_phys),
1514 KUNIT_CASE(kmem_cache_oob),
1515 KUNIT_CASE(kmem_cache_accounted),
1516 KUNIT_CASE(kmem_cache_bulk),
1517 KUNIT_CASE(kasan_global_oob_right),
1518 KUNIT_CASE(kasan_global_oob_left),
1519 KUNIT_CASE(kasan_stack_oob),
1520 KUNIT_CASE(kasan_alloca_oob_left),
1521 KUNIT_CASE(kasan_alloca_oob_right),
1522 KUNIT_CASE(ksize_unpoisons_memory),
1523 KUNIT_CASE(ksize_uaf),
1524 KUNIT_CASE(kmem_cache_double_free),
1525 KUNIT_CASE(kmem_cache_invalid_free),
1526 KUNIT_CASE(kmem_cache_double_destroy),
1527 KUNIT_CASE(kasan_memchr),
1528 KUNIT_CASE(kasan_memcmp),
1529 KUNIT_CASE(kasan_strings),
1530 KUNIT_CASE(kasan_bitops_generic),
1531 KUNIT_CASE(kasan_bitops_tags),
1532 KUNIT_CASE(kmalloc_double_kzfree),
1533 KUNIT_CASE(rcu_uaf),
1534 KUNIT_CASE(workqueue_uaf),
1535 KUNIT_CASE(vmalloc_helpers_tags),
1536 KUNIT_CASE(vmalloc_oob),
1537 KUNIT_CASE(vmap_tags),
1538 KUNIT_CASE(vm_map_ram_tags),
1539 KUNIT_CASE(match_all_not_assigned),
1540 KUNIT_CASE(match_all_ptr_tag),
1541 KUNIT_CASE(match_all_mem_tag),
1542 {}
1543 };
1544
1545 static struct kunit_suite kasan_kunit_test_suite = {
1546 .name = "kasan",
1547 .test_cases = kasan_kunit_test_cases,
1548 .exit = kasan_test_exit,
1549 .suite_init = kasan_suite_init,
1550 .suite_exit = kasan_suite_exit,
1551 };
1552
1553 kunit_test_suite(kasan_kunit_test_suite);
1554
1555 MODULE_LICENSE("GPL");
1556