kasan.h 16.6 KB
Newer Older
1
/* SPDX-License-Identifier: GPL-2.0 */
2
3
4
5
#ifndef __MM_KASAN_KASAN_H
#define __MM_KASAN_KASAN_H

#include <linux/kasan.h>
6
#include <linux/kasan-tags.h>
7
#include <linux/kfence.h>
8
#include <linux/stackdepot.h>
9

10
#ifdef CONFIG_KASAN_HW_TAGS
11

12
#include <linux/static_key.h>
13
#include "../slab.h"
14

15
DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
16
extern bool kasan_flag_async __ro_after_init;
17
extern bool kasan_flag_asymm __ro_after_init;
18

19
20
21
22
static inline bool kasan_stack_collection_enabled(void)
{
	return static_branch_unlikely(&kasan_flag_stacktrace);
}
23

24
static inline bool kasan_async_fault_possible(void)
25
{
26
27
28
29
30
31
	return kasan_flag_async | kasan_flag_asymm;
}

static inline bool kasan_sync_fault_possible(void)
{
	return !kasan_flag_async | kasan_flag_asymm;
32
}
33
#else
34

35
36
37
38
static inline bool kasan_stack_collection_enabled(void)
{
	return true;
}
39

40
static inline bool kasan_async_fault_possible(void)
41
42
43
44
{
	return false;
}

45
46
47
48
49
static inline bool kasan_sync_fault_possible(void)
{
	return true;
}

50
51
#endif

52
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
53
#define KASAN_GRANULE_SIZE	(1UL << KASAN_SHADOW_SCALE_SHIFT)
54
55
56
57
58
#else
#include <asm/mte-kasan.h>
#define KASAN_GRANULE_SIZE	MTE_GRANULE_SIZE
#endif

59
#define KASAN_GRANULE_MASK	(KASAN_GRANULE_SIZE - 1)
60

61
62
#define KASAN_MEMORY_PER_SHADOW_PAGE	(KASAN_GRANULE_SIZE << PAGE_SHIFT)

63
#ifdef CONFIG_KASAN_GENERIC
64
65
66
67
#define KASAN_FREE_PAGE         0xFF  /* page was freed */
#define KASAN_PAGE_REDZONE      0xFE  /* redzone for kmalloc_large allocations */
#define KASAN_KMALLOC_REDZONE   0xFC  /* redzone inside slub object */
#define KASAN_KMALLOC_FREE      0xFB  /* object was freed (kmem_cache_free/kfree) */
68
#define KASAN_KMALLOC_FREETRACK 0xFA  /* object was freed and has free track set */
69
70
71
72
73
#else
#define KASAN_FREE_PAGE         KASAN_TAG_INVALID
#define KASAN_PAGE_REDZONE      KASAN_TAG_INVALID
#define KASAN_KMALLOC_REDZONE   KASAN_TAG_INVALID
#define KASAN_KMALLOC_FREE      KASAN_TAG_INVALID
74
#define KASAN_KMALLOC_FREETRACK KASAN_TAG_INVALID
75
76
#endif

77
78
#define KASAN_GLOBAL_REDZONE    0xF9  /* redzone for global variable */
#define KASAN_VMALLOC_INVALID   0xF8  /* unallocated space in vmapped page */
79

80
81
82
83
84
85
86
87
88
/*
 * Stack redzone shadow values
 * (Those are compiler's ABI, don't change them)
 */
#define KASAN_STACK_LEFT        0xF1
#define KASAN_STACK_MID         0xF2
#define KASAN_STACK_RIGHT       0xF3
#define KASAN_STACK_PARTIAL     0xF4

89
90
91
92
93
94
95
96
/*
 * alloca redzone shadow values
 */
#define KASAN_ALLOCA_LEFT	0xCA
#define KASAN_ALLOCA_RIGHT	0xCB

#define KASAN_ALLOCA_REDZONE_SIZE	32

97
98
99
100
101
/*
 * Stack frame marker (compiler ABI).
 */
#define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3

102
103
104
105
/* Don't break randconfig/all*config builds */
#ifndef KASAN_ABI_VERSION
#define KASAN_ABI_VERSION 1
#endif
106

107
108
109
110
111
112
113
/* Metadata layout customization. */
#define META_BYTES_PER_BLOCK 1
#define META_BLOCKS_PER_ROW 16
#define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
#define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE)
#define META_ROWS_AROUND_ADDR 2

114
115
116
117
118
119
120
121
struct kasan_access_info {
	const void *access_addr;
	const void *first_bad_addr;
	size_t access_size;
	bool is_write;
	unsigned long ip;
};

122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/* The layout of struct dictated by compiler */
struct kasan_source_location {
	const char *filename;
	int line_no;
	int column_no;
};

/* The layout of struct dictated by compiler */
struct kasan_global {
	const void *beg;		/* Address of the beginning of the global variable. */
	size_t size;			/* Size of the global variable. */
	size_t size_with_redzone;	/* Size of the variable + size of the red zone. 32 bytes aligned */
	const void *name;
	const void *module_name;	/* Name of the module where the global variable is declared. */
	unsigned long has_dynamic_init;	/* This needed for C++ */
#if KASAN_ABI_VERSION >= 4
	struct kasan_source_location *location;
#endif
140
141
142
#if KASAN_ABI_VERSION >= 5
	char *odr_indicator;
#endif
143
144
};

Alexander Potapenko's avatar
Alexander Potapenko committed
145
146
147
148
/**
 * Structures to keep alloc and free tracks *
 */

149
150
#define KASAN_STACK_DEPTH 64

Alexander Potapenko's avatar
Alexander Potapenko committed
151
struct kasan_track {
152
153
	u32 pid;
	depot_stack_handle_t stack;
Alexander Potapenko's avatar
Alexander Potapenko committed
154
155
};

156
#if defined(CONFIG_KASAN_TAGS_IDENTIFY) && defined(CONFIG_KASAN_SW_TAGS)
157
158
159
160
161
#define KASAN_NR_FREE_STACKS 5
#else
#define KASAN_NR_FREE_STACKS 1
#endif

Alexander Potapenko's avatar
Alexander Potapenko committed
162
struct kasan_alloc_meta {
163
	struct kasan_track alloc_track;
164
165
#ifdef CONFIG_KASAN_GENERIC
	/*
166
	 * The auxiliary stack is stored into struct kasan_alloc_meta.
167
168
169
	 * The free stack is stored into struct kasan_free_meta.
	 */
	depot_stack_handle_t aux_stack[2];
170
#else
171
	struct kasan_track free_track[KASAN_NR_FREE_STACKS];
172
#endif
173
#ifdef CONFIG_KASAN_TAGS_IDENTIFY
174
175
176
	u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
	u8 free_track_idx;
#endif
Alexander Potapenko's avatar
Alexander Potapenko committed
177
178
};

179
180
181
struct qlist_node {
	struct qlist_node *next;
};
182
183
184
185
186
187
188
189
190

/*
 * Generic mode either stores free meta in the object itself or in the redzone
 * after the object. In the former case free meta offset is 0, in the latter
 * case it has some sane value smaller than INT_MAX. Use INT_MAX as free meta
 * offset when free meta isn't present.
 */
#define KASAN_NO_FREE_META INT_MAX

Alexander Potapenko's avatar
Alexander Potapenko committed
191
struct kasan_free_meta {
192
#ifdef CONFIG_KASAN_GENERIC
193
194
195
196
	/* This field is used while the object is in the quarantine.
	 * Otherwise it might be used for the allocator freelist.
	 */
	struct qlist_node quarantine_link;
197
198
	struct kasan_track free_track;
#endif
Alexander Potapenko's avatar
Alexander Potapenko committed
199
200
};

201
202
struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
						const void *object);
203
#ifdef CONFIG_KASAN_GENERIC
204
205
struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
						const void *object);
206
#endif
Alexander Potapenko's avatar
Alexander Potapenko committed
207

208
209
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

210
211
212
213
214
215
static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
{
	return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
		<< KASAN_SHADOW_SCALE_SHIFT);
}

216
static inline bool addr_has_metadata(const void *addr)
217
218
219
220
{
	return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
}

221
/**
222
 * kasan_check_range - Check memory region, and report if invalid access.
223
224
225
226
227
228
 * @addr: the accessed address
 * @size: the accessed size
 * @write: true if access is a write access
 * @ret_ip: return address
 * @return: true if access was valid, false if invalid
 */
229
bool kasan_check_range(unsigned long addr, size_t size, bool write,
230
231
				unsigned long ret_ip);

232
233
234
235
#else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */

static inline bool addr_has_metadata(const void *addr)
{
236
	return (is_vmalloc_addr(addr) || virt_addr_valid(addr));
237
238
239
240
}

#endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */

241
#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
242
void kasan_print_tags(u8 addr_tag, const void *addr);
243
#else
244
static inline void kasan_print_tags(u8 addr_tag, const void *addr) { }
245
246
#endif

247
248
249
void *kasan_find_first_bad_addr(void *addr, size_t size);
const char *kasan_get_bug_type(struct kasan_access_info *info);
void kasan_metadata_fetch_row(char *buffer, void *row);
250

251
#if defined(CONFIG_KASAN_GENERIC) && defined(CONFIG_KASAN_STACK)
252
void kasan_print_address_stack_frame(const void *addr);
253
#else
254
static inline void kasan_print_address_stack_frame(const void *addr) { }
255
256
#endif

257
bool kasan_report(unsigned long addr, size_t size,
258
		bool is_write, unsigned long ip);
259
void kasan_report_invalid_free(void *object, unsigned long ip);
260

261
262
struct page *kasan_addr_to_page(const void *addr);

263
depot_stack_handle_t kasan_save_stack(gfp_t flags);
264
265
266
267
void kasan_set_track(struct kasan_track *track, gfp_t flags);
void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag);
struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
				void *object, u8 tag);
268

269
270
#if defined(CONFIG_KASAN_GENERIC) && \
	(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
271
272
273
bool kasan_quarantine_put(struct kmem_cache *cache, void *object);
void kasan_quarantine_reduce(void);
void kasan_quarantine_remove_cache(struct kmem_cache *cache);
274
#else
275
276
277
static inline bool kasan_quarantine_put(struct kmem_cache *cache, void *object) { return false; }
static inline void kasan_quarantine_reduce(void) { }
static inline void kasan_quarantine_remove_cache(struct kmem_cache *cache) { }
278
279
#endif

280
#ifndef arch_kasan_set_tag
281
282
283
284
static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
{
	return addr;
}
285
286
287
288
289
290
291
292
#endif
#ifndef arch_kasan_get_tag
#define arch_kasan_get_tag(addr)	0
#endif

#define set_tag(addr, tag)	((void *)arch_kasan_set_tag((addr), (tag)))
#define get_tag(addr)		arch_kasan_get_tag(addr)

293
294
#ifdef CONFIG_KASAN_HW_TAGS

295
296
297
298
299
#ifndef arch_enable_tagging_sync
#define arch_enable_tagging_sync()
#endif
#ifndef arch_enable_tagging_async
#define arch_enable_tagging_async()
300
#endif
301
302
303
#ifndef arch_enable_tagging_asymm
#define arch_enable_tagging_asymm()
#endif
304
305
306
#ifndef arch_force_async_tag_fault
#define arch_force_async_tag_fault()
#endif
307
308
309
310
311
312
313
#ifndef arch_get_random_tag
#define arch_get_random_tag()	(0xFF)
#endif
#ifndef arch_get_mem_tag
#define arch_get_mem_tag(addr)	(0xFF)
#endif
#ifndef arch_set_mem_tag_range
314
#define arch_set_mem_tag_range(addr, size, tag, init) ((void *)(addr))
315
316
#endif

317
318
#define hw_enable_tagging_sync()		arch_enable_tagging_sync()
#define hw_enable_tagging_async()		arch_enable_tagging_async()
319
#define hw_enable_tagging_asymm()		arch_enable_tagging_asymm()
320
#define hw_force_async_tag_fault()		arch_force_async_tag_fault()
321
322
#define hw_get_random_tag()			arch_get_random_tag()
#define hw_get_mem_tag(addr)			arch_get_mem_tag(addr)
323
324
#define hw_set_mem_tag_range(addr, size, tag, init) \
			arch_set_mem_tag_range((addr), (size), (tag), (init))
325

326
327
#else /* CONFIG_KASAN_HW_TAGS */

328
329
#define hw_enable_tagging_sync()
#define hw_enable_tagging_async()
330
#define hw_enable_tagging_asymm()
331

332
333
#endif /* CONFIG_KASAN_HW_TAGS */

334
335
#if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)

336
void kasan_enable_tagging_sync(void);
337
void kasan_force_async_fault(void);
338
339
340

#else /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */

341
static inline void kasan_enable_tagging_sync(void) { }
342
static inline void kasan_force_async_fault(void) { }
343
344
345

#endif /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */

346
#ifdef CONFIG_KASAN_SW_TAGS
347
u8 kasan_random_tag(void);
348
#elif defined(CONFIG_KASAN_HW_TAGS)
349
static inline u8 kasan_random_tag(void) { return hw_get_random_tag(); }
350
#else
351
static inline u8 kasan_random_tag(void) { return 0; }
352
353
#endif

354
355
#ifdef CONFIG_KASAN_HW_TAGS

356
static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init)
357
{
358
	addr = kasan_reset_tag(addr);
359
360

	/* Skip KFENCE memory if called explicitly outside of sl*b. */
361
	if (is_kfence_address(addr))
362
363
		return;

364
365
366
367
368
	if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
		return;
	if (WARN_ON(size & KASAN_GRANULE_MASK))
		return;

369
	hw_set_mem_tag_range((void *)addr, size, value, init);
370
371
}

372
static inline void kasan_unpoison(const void *addr, size_t size, bool init)
373
{
374
	u8 tag = get_tag(addr);
375

376
	addr = kasan_reset_tag(addr);
377
378

	/* Skip KFENCE memory if called explicitly outside of sl*b. */
379
380
381
382
	if (is_kfence_address(addr))
		return;

	if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
383
		return;
384
385
386
387
388
389
390
391
392
393
394
	/*
	 * Explicitly initialize the memory with the precise object size to
	 * avoid overwriting the SLAB redzone. This disables initialization in
	 * the arch code and may thus lead to performance penalty. The penalty
	 * is accepted since SLAB redzones aren't enabled in production builds.
	 */
	if (__slub_debug_enabled() &&
	    init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
		init = false;
		memzero_explicit((void *)addr, size);
	}
395
	size = round_up(size, KASAN_GRANULE_SIZE);
396

397
	hw_set_mem_tag_range((void *)addr, size, tag, init);
398
399
}

400
static inline bool kasan_byte_accessible(const void *addr)
401
402
{
	u8 ptr_tag = get_tag(addr);
403
	u8 mem_tag = hw_get_mem_tag((void *)addr);
404

405
	return ptr_tag == KASAN_TAG_KERNEL || ptr_tag == mem_tag;
406
407
408
409
}

#else /* CONFIG_KASAN_HW_TAGS */

410
/**
Ingo Molnar's avatar
Ingo Molnar committed
411
 * kasan_poison - mark the memory range as inaccessible
412
 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
413
 * @size - range size, must be aligned to KASAN_GRANULE_SIZE
414
 * @value - value that's written to metadata for the range
415
 * @init - whether to initialize the memory range (only for hardware tag-based)
416
417
418
 *
 * The size gets aligned to KASAN_GRANULE_SIZE before marking the range.
 */
419
void kasan_poison(const void *addr, size_t size, u8 value, bool init);
420
421
422
423

/**
 * kasan_unpoison - mark the memory range as accessible
 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
424
 * @size - range size, can be unaligned
425
 * @init - whether to initialize the memory range (only for hardware tag-based)
426
427
428
429
430
431
 *
 * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before
 * marking the range.
 * For the generic mode, the last granule of the memory range gets partially
 * unpoisoned based on the @size.
 */
432
void kasan_unpoison(const void *addr, size_t size, bool init);
433

434
bool kasan_byte_accessible(const void *addr);
435
436
437

#endif /* CONFIG_KASAN_HW_TAGS */

438
439
440
441
#ifdef CONFIG_KASAN_GENERIC

/**
 * kasan_poison_last_granule - mark the last granule of the memory range as
Ingo Molnar's avatar
Ingo Molnar committed
442
 * inaccessible
443
444
445
446
447
448
449
450
451
452
453
454
455
456
 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
 * @size - range size
 *
 * This function is only available for the generic mode, as it's the only mode
 * that has partially poisoned memory granules.
 */
void kasan_poison_last_granule(const void *address, size_t size);

#else /* CONFIG_KASAN_GENERIC */

static inline void kasan_poison_last_granule(const void *address, size_t size) { }

#endif /* CONFIG_KASAN_GENERIC */

457
458
459
460
461
462
#ifndef kasan_arch_is_ready
static inline bool kasan_arch_is_ready(void)	{ return true; }
#elif !defined(CONFIG_KASAN_GENERIC) || !defined(CONFIG_KASAN_OUTLINE)
#error kasan_arch_is_ready only works in KASAN generic outline mode!
#endif

463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
/*
 * Exported functions for interfaces called from assembly or from generated
 * code. Declarations here to avoid warning about missing declarations.
 */
asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
void __asan_register_globals(struct kasan_global *globals, size_t size);
void __asan_unregister_globals(struct kasan_global *globals, size_t size);
void __asan_handle_no_return(void);
void __asan_alloca_poison(unsigned long addr, size_t size);
void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);

void __asan_load1(unsigned long addr);
void __asan_store1(unsigned long addr);
void __asan_load2(unsigned long addr);
void __asan_store2(unsigned long addr);
void __asan_load4(unsigned long addr);
void __asan_store4(unsigned long addr);
void __asan_load8(unsigned long addr);
void __asan_store8(unsigned long addr);
void __asan_load16(unsigned long addr);
void __asan_store16(unsigned long addr);
484
485
void __asan_loadN(unsigned long addr, size_t size);
void __asan_storeN(unsigned long addr, size_t size);
486
487
488
489
490
491
492
493
494
495
496

void __asan_load1_noabort(unsigned long addr);
void __asan_store1_noabort(unsigned long addr);
void __asan_load2_noabort(unsigned long addr);
void __asan_store2_noabort(unsigned long addr);
void __asan_load4_noabort(unsigned long addr);
void __asan_store4_noabort(unsigned long addr);
void __asan_load8_noabort(unsigned long addr);
void __asan_store8_noabort(unsigned long addr);
void __asan_load16_noabort(unsigned long addr);
void __asan_store16_noabort(unsigned long addr);
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
void __asan_loadN_noabort(unsigned long addr, size_t size);
void __asan_storeN_noabort(unsigned long addr, size_t size);

void __asan_report_load1_noabort(unsigned long addr);
void __asan_report_store1_noabort(unsigned long addr);
void __asan_report_load2_noabort(unsigned long addr);
void __asan_report_store2_noabort(unsigned long addr);
void __asan_report_load4_noabort(unsigned long addr);
void __asan_report_store4_noabort(unsigned long addr);
void __asan_report_load8_noabort(unsigned long addr);
void __asan_report_store8_noabort(unsigned long addr);
void __asan_report_load16_noabort(unsigned long addr);
void __asan_report_store16_noabort(unsigned long addr);
void __asan_report_load_n_noabort(unsigned long addr, size_t size);
void __asan_report_store_n_noabort(unsigned long addr, size_t size);
512
513
514
515
516
517
518
519

void __asan_set_shadow_00(const void *addr, size_t size);
void __asan_set_shadow_f1(const void *addr, size_t size);
void __asan_set_shadow_f2(const void *addr, size_t size);
void __asan_set_shadow_f3(const void *addr, size_t size);
void __asan_set_shadow_f5(const void *addr, size_t size);
void __asan_set_shadow_f8(const void *addr, size_t size);

520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
void __hwasan_load1_noabort(unsigned long addr);
void __hwasan_store1_noabort(unsigned long addr);
void __hwasan_load2_noabort(unsigned long addr);
void __hwasan_store2_noabort(unsigned long addr);
void __hwasan_load4_noabort(unsigned long addr);
void __hwasan_store4_noabort(unsigned long addr);
void __hwasan_load8_noabort(unsigned long addr);
void __hwasan_store8_noabort(unsigned long addr);
void __hwasan_load16_noabort(unsigned long addr);
void __hwasan_store16_noabort(unsigned long addr);
void __hwasan_loadN_noabort(unsigned long addr, size_t size);
void __hwasan_storeN_noabort(unsigned long addr, size_t size);

void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);

535
#endif