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