1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __MM_KASAN_KASAN_H
3 #define __MM_KASAN_KASAN_H
4
5 #include <linux/kasan.h>
6 #include <linux/kasan-tags.h>
7 #include <linux/kfence.h>
8 #include <linux/stackdepot.h>
9
10 #if IS_ENABLED(CONFIG_KUNIT)
11
12 /* Used in KUnit-compatible KASAN tests. */
13 struct kunit_kasan_status {
14 bool report_found;
15 bool sync_fault;
16 };
17
18 #endif
19
20 #ifdef CONFIG_KASAN_HW_TAGS
21
22 #include <linux/static_key.h>
23 #include "../slab.h"
24
25 DECLARE_STATIC_KEY_TRUE(kasan_flag_vmalloc);
26 DECLARE_STATIC_KEY_TRUE(kasan_flag_stacktrace);
27
28 enum kasan_mode {
29 KASAN_MODE_SYNC,
30 KASAN_MODE_ASYNC,
31 KASAN_MODE_ASYMM,
32 };
33
34 extern enum kasan_mode kasan_mode __ro_after_init;
35
kasan_vmalloc_enabled(void)36 static inline bool kasan_vmalloc_enabled(void)
37 {
38 return static_branch_likely(&kasan_flag_vmalloc);
39 }
40
kasan_stack_collection_enabled(void)41 static inline bool kasan_stack_collection_enabled(void)
42 {
43 return static_branch_unlikely(&kasan_flag_stacktrace);
44 }
45
kasan_async_fault_possible(void)46 static inline bool kasan_async_fault_possible(void)
47 {
48 return kasan_mode == KASAN_MODE_ASYNC || kasan_mode == KASAN_MODE_ASYMM;
49 }
50
kasan_sync_fault_possible(void)51 static inline bool kasan_sync_fault_possible(void)
52 {
53 return kasan_mode == KASAN_MODE_SYNC || kasan_mode == KASAN_MODE_ASYMM;
54 }
55 #else
56
kasan_stack_collection_enabled(void)57 static inline bool kasan_stack_collection_enabled(void)
58 {
59 return true;
60 }
61
kasan_async_fault_possible(void)62 static inline bool kasan_async_fault_possible(void)
63 {
64 return false;
65 }
66
kasan_sync_fault_possible(void)67 static inline bool kasan_sync_fault_possible(void)
68 {
69 return true;
70 }
71
72 #endif
73
74 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
75 #define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
76 #else
77 #include <asm/mte-kasan.h>
78 #define KASAN_GRANULE_SIZE MTE_GRANULE_SIZE
79 #endif
80
81 #define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1)
82
83 #define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT)
84
85 #ifdef CONFIG_KASAN_GENERIC
86 #define KASAN_FREE_PAGE 0xFF /* page was freed */
87 #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */
88 #define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */
89 #define KASAN_KMALLOC_FREE 0xFB /* object was freed (kmem_cache_free/kfree) */
90 #define KASAN_VMALLOC_INVALID 0xF8 /* unallocated space in vmapped page */
91 #else
92 #define KASAN_FREE_PAGE KASAN_TAG_INVALID
93 #define KASAN_PAGE_REDZONE KASAN_TAG_INVALID
94 #define KASAN_KMALLOC_REDZONE KASAN_TAG_INVALID
95 #define KASAN_KMALLOC_FREE KASAN_TAG_INVALID
96 #define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only for SW_TAGS */
97 #endif
98
99 #ifdef CONFIG_KASAN_GENERIC
100
101 #define KASAN_KMALLOC_FREETRACK 0xFA /* object was freed and has free track set */
102 #define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */
103
104 /*
105 * Stack redzone shadow values
106 * (Those are compiler's ABI, don't change them)
107 */
108 #define KASAN_STACK_LEFT 0xF1
109 #define KASAN_STACK_MID 0xF2
110 #define KASAN_STACK_RIGHT 0xF3
111 #define KASAN_STACK_PARTIAL 0xF4
112
113 /*
114 * alloca redzone shadow values
115 */
116 #define KASAN_ALLOCA_LEFT 0xCA
117 #define KASAN_ALLOCA_RIGHT 0xCB
118
119 #define KASAN_ALLOCA_REDZONE_SIZE 32
120
121 /*
122 * Stack frame marker (compiler ABI).
123 */
124 #define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3
125
126 /* Don't break randconfig/all*config builds */
127 #ifndef KASAN_ABI_VERSION
128 #define KASAN_ABI_VERSION 1
129 #endif
130
131 #endif /* CONFIG_KASAN_GENERIC */
132
133 /* Metadata layout customization. */
134 #define META_BYTES_PER_BLOCK 1
135 #define META_BLOCKS_PER_ROW 16
136 #define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
137 #define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE)
138 #define META_ROWS_AROUND_ADDR 2
139
140 struct kasan_access_info {
141 const void *access_addr;
142 const void *first_bad_addr;
143 size_t access_size;
144 bool is_write;
145 unsigned long ip;
146 };
147
148 /* The layout of struct dictated by compiler */
149 struct kasan_source_location {
150 const char *filename;
151 int line_no;
152 int column_no;
153 };
154
155 /* The layout of struct dictated by compiler */
156 struct kasan_global {
157 const void *beg; /* Address of the beginning of the global variable. */
158 size_t size; /* Size of the global variable. */
159 size_t size_with_redzone; /* Size of the variable + size of the red zone. 32 bytes aligned */
160 const void *name;
161 const void *module_name; /* Name of the module where the global variable is declared. */
162 unsigned long has_dynamic_init; /* This needed for C++ */
163 #if KASAN_ABI_VERSION >= 4
164 struct kasan_source_location *location;
165 #endif
166 #if KASAN_ABI_VERSION >= 5
167 char *odr_indicator;
168 #endif
169 };
170
171 /**
172 * Structures to keep alloc and free tracks *
173 */
174
175 #define KASAN_STACK_DEPTH 64
176
177 struct kasan_track {
178 u32 pid;
179 depot_stack_handle_t stack;
180 };
181
182 #if defined(CONFIG_KASAN_TAGS_IDENTIFY) && defined(CONFIG_KASAN_SW_TAGS)
183 #define KASAN_NR_FREE_STACKS 5
184 #else
185 #define KASAN_NR_FREE_STACKS 1
186 #endif
187
188 struct kasan_alloc_meta {
189 struct kasan_track alloc_track;
190 #ifdef CONFIG_KASAN_GENERIC
191 /*
192 * The auxiliary stack is stored into struct kasan_alloc_meta.
193 * The free stack is stored into struct kasan_free_meta.
194 */
195 depot_stack_handle_t aux_stack[2];
196 #else
197 struct kasan_track free_track[KASAN_NR_FREE_STACKS];
198 #endif
199 #ifdef CONFIG_KASAN_TAGS_IDENTIFY
200 u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
201 u8 free_track_idx;
202 #endif
203 };
204
205 struct qlist_node {
206 struct qlist_node *next;
207 };
208
209 /*
210 * Generic mode either stores free meta in the object itself or in the redzone
211 * after the object. In the former case free meta offset is 0, in the latter
212 * case it has some sane value smaller than INT_MAX. Use INT_MAX as free meta
213 * offset when free meta isn't present.
214 */
215 #define KASAN_NO_FREE_META INT_MAX
216
217 struct kasan_free_meta {
218 #ifdef CONFIG_KASAN_GENERIC
219 /* This field is used while the object is in the quarantine.
220 * Otherwise it might be used for the allocator freelist.
221 */
222 struct qlist_node quarantine_link;
223 struct kasan_track free_track;
224 #endif
225 };
226
227 struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
228 const void *object);
229 #ifdef CONFIG_KASAN_GENERIC
230 struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
231 const void *object);
232 #endif
233
234 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
235
kasan_shadow_to_mem(const void * shadow_addr)236 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
237 {
238 return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
239 << KASAN_SHADOW_SCALE_SHIFT);
240 }
241
addr_has_metadata(const void * addr)242 static inline bool addr_has_metadata(const void *addr)
243 {
244 return (addr >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
245 }
246
247 /**
248 * kasan_check_range - Check memory region, and report if invalid access.
249 * @addr: the accessed address
250 * @size: the accessed size
251 * @write: true if access is a write access
252 * @ret_ip: return address
253 * @return: true if access was valid, false if invalid
254 */
255 bool kasan_check_range(unsigned long addr, size_t size, bool write,
256 unsigned long ret_ip);
257
258 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
259
addr_has_metadata(const void * addr)260 static inline bool addr_has_metadata(const void *addr)
261 {
262 return (is_vmalloc_addr(addr) || virt_addr_valid(addr));
263 }
264
265 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
266
267 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
268 void kasan_print_tags(u8 addr_tag, const void *addr);
269 #else
kasan_print_tags(u8 addr_tag,const void * addr)270 static inline void kasan_print_tags(u8 addr_tag, const void *addr) { }
271 #endif
272
273 void *kasan_find_first_bad_addr(void *addr, size_t size);
274 const char *kasan_get_bug_type(struct kasan_access_info *info);
275 void kasan_metadata_fetch_row(char *buffer, void *row);
276
277 #if defined(CONFIG_KASAN_GENERIC) && defined(CONFIG_KASAN_STACK)
278 void kasan_print_address_stack_frame(const void *addr);
279 #else
kasan_print_address_stack_frame(const void * addr)280 static inline void kasan_print_address_stack_frame(const void *addr) { }
281 #endif
282
283 bool kasan_report(unsigned long addr, size_t size,
284 bool is_write, unsigned long ip);
285 void kasan_report_invalid_free(void *object, unsigned long ip);
286
287 struct page *kasan_addr_to_page(const void *addr);
288
289 depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
290 void kasan_set_track(struct kasan_track *track, gfp_t flags);
291 void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag);
292 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
293 void *object, u8 tag);
294
295 #if defined(CONFIG_KASAN_GENERIC) && \
296 (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
297 bool kasan_quarantine_put(struct kmem_cache *cache, void *object);
298 void kasan_quarantine_reduce(void);
299 void kasan_quarantine_remove_cache(struct kmem_cache *cache);
300 #else
kasan_quarantine_put(struct kmem_cache * cache,void * object)301 static inline bool kasan_quarantine_put(struct kmem_cache *cache, void *object) { return false; }
kasan_quarantine_reduce(void)302 static inline void kasan_quarantine_reduce(void) { }
kasan_quarantine_remove_cache(struct kmem_cache * cache)303 static inline void kasan_quarantine_remove_cache(struct kmem_cache *cache) { }
304 #endif
305
306 #ifndef arch_kasan_set_tag
arch_kasan_set_tag(const void * addr,u8 tag)307 static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
308 {
309 return addr;
310 }
311 #endif
312 #ifndef arch_kasan_get_tag
313 #define arch_kasan_get_tag(addr) 0
314 #endif
315
316 #define set_tag(addr, tag) ((void *)arch_kasan_set_tag((addr), (tag)))
317 #define get_tag(addr) arch_kasan_get_tag(addr)
318
319 #ifdef CONFIG_KASAN_HW_TAGS
320
321 #ifndef arch_enable_tagging_sync
322 #define arch_enable_tagging_sync()
323 #endif
324 #ifndef arch_enable_tagging_async
325 #define arch_enable_tagging_async()
326 #endif
327 #ifndef arch_enable_tagging_asymm
328 #define arch_enable_tagging_asymm()
329 #endif
330 #ifndef arch_force_async_tag_fault
331 #define arch_force_async_tag_fault()
332 #endif
333 #ifndef arch_get_random_tag
334 #define arch_get_random_tag() (0xFF)
335 #endif
336 #ifndef arch_get_mem_tag
337 #define arch_get_mem_tag(addr) (0xFF)
338 #endif
339 #ifndef arch_set_mem_tag_range
340 #define arch_set_mem_tag_range(addr, size, tag, init) ((void *)(addr))
341 #endif
342
343 #define hw_enable_tagging_sync() arch_enable_tagging_sync()
344 #define hw_enable_tagging_async() arch_enable_tagging_async()
345 #define hw_enable_tagging_asymm() arch_enable_tagging_asymm()
346 #define hw_force_async_tag_fault() arch_force_async_tag_fault()
347 #define hw_get_random_tag() arch_get_random_tag()
348 #define hw_get_mem_tag(addr) arch_get_mem_tag(addr)
349 #define hw_set_mem_tag_range(addr, size, tag, init) \
350 arch_set_mem_tag_range((addr), (size), (tag), (init))
351
352 void kasan_enable_tagging(void);
353
354 #else /* CONFIG_KASAN_HW_TAGS */
355
356 #define hw_enable_tagging_sync()
357 #define hw_enable_tagging_async()
358 #define hw_enable_tagging_asymm()
359
kasan_enable_tagging(void)360 static inline void kasan_enable_tagging(void) { }
361
362 #endif /* CONFIG_KASAN_HW_TAGS */
363
364 #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
365
366 void kasan_force_async_fault(void);
367
368 #else /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */
369
kasan_force_async_fault(void)370 static inline void kasan_force_async_fault(void) { }
371
372 #endif /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */
373
374 #ifdef CONFIG_KASAN_SW_TAGS
375 u8 kasan_random_tag(void);
376 #elif defined(CONFIG_KASAN_HW_TAGS)
kasan_random_tag(void)377 static inline u8 kasan_random_tag(void) { return hw_get_random_tag(); }
378 #else
kasan_random_tag(void)379 static inline u8 kasan_random_tag(void) { return 0; }
380 #endif
381
382 #ifdef CONFIG_KASAN_HW_TAGS
383
kasan_poison(const void * addr,size_t size,u8 value,bool init)384 static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init)
385 {
386 addr = kasan_reset_tag(addr);
387
388 /* Skip KFENCE memory if called explicitly outside of sl*b. */
389 if (is_kfence_address(addr))
390 return;
391
392 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
393 return;
394 if (WARN_ON(size & KASAN_GRANULE_MASK))
395 return;
396
397 hw_set_mem_tag_range((void *)addr, size, value, init);
398 }
399
kasan_unpoison(const void * addr,size_t size,bool init)400 static inline void kasan_unpoison(const void *addr, size_t size, bool init)
401 {
402 u8 tag = get_tag(addr);
403
404 addr = kasan_reset_tag(addr);
405
406 /* Skip KFENCE memory if called explicitly outside of sl*b. */
407 if (is_kfence_address(addr))
408 return;
409
410 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
411 return;
412 /*
413 * Explicitly initialize the memory with the precise object size to
414 * avoid overwriting the SLAB redzone. This disables initialization in
415 * the arch code and may thus lead to performance penalty. The penalty
416 * is accepted since SLAB redzones aren't enabled in production builds.
417 */
418 if (__slub_debug_enabled() &&
419 init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
420 init = false;
421 memzero_explicit((void *)addr, size);
422 }
423 size = round_up(size, KASAN_GRANULE_SIZE);
424
425 hw_set_mem_tag_range((void *)addr, size, tag, init);
426 }
427
kasan_byte_accessible(const void * addr)428 static inline bool kasan_byte_accessible(const void *addr)
429 {
430 u8 ptr_tag = get_tag(addr);
431 u8 mem_tag = hw_get_mem_tag((void *)addr);
432
433 return ptr_tag == KASAN_TAG_KERNEL || ptr_tag == mem_tag;
434 }
435
436 #else /* CONFIG_KASAN_HW_TAGS */
437
438 /**
439 * kasan_poison - mark the memory range as unaccessible
440 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
441 * @size - range size, must be aligned to KASAN_GRANULE_SIZE
442 * @value - value that's written to metadata for the range
443 * @init - whether to initialize the memory range (only for hardware tag-based)
444 *
445 * The size gets aligned to KASAN_GRANULE_SIZE before marking the range.
446 */
447 void kasan_poison(const void *addr, size_t size, u8 value, bool init);
448
449 /**
450 * kasan_unpoison - mark the memory range as accessible
451 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
452 * @size - range size, can be unaligned
453 * @init - whether to initialize the memory range (only for hardware tag-based)
454 *
455 * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before
456 * marking the range.
457 * For the generic mode, the last granule of the memory range gets partially
458 * unpoisoned based on the @size.
459 */
460 void kasan_unpoison(const void *addr, size_t size, bool init);
461
462 bool kasan_byte_accessible(const void *addr);
463
464 #endif /* CONFIG_KASAN_HW_TAGS */
465
466 #ifdef CONFIG_KASAN_GENERIC
467
468 /**
469 * kasan_poison_last_granule - mark the last granule of the memory range as
470 * unaccessible
471 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
472 * @size - range size
473 *
474 * This function is only available for the generic mode, as it's the only mode
475 * that has partially poisoned memory granules.
476 */
477 void kasan_poison_last_granule(const void *address, size_t size);
478
479 #else /* CONFIG_KASAN_GENERIC */
480
kasan_poison_last_granule(const void * address,size_t size)481 static inline void kasan_poison_last_granule(const void *address, size_t size) { }
482
483 #endif /* CONFIG_KASAN_GENERIC */
484
485 #ifndef kasan_arch_is_ready
kasan_arch_is_ready(void)486 static inline bool kasan_arch_is_ready(void) { return true; }
487 #elif !defined(CONFIG_KASAN_GENERIC) || !defined(CONFIG_KASAN_OUTLINE)
488 #error kasan_arch_is_ready only works in KASAN generic outline mode!
489 #endif
490
491 /*
492 * Exported functions for interfaces called from assembly or from generated
493 * code. Declarations here to avoid warning about missing declarations.
494 */
495 asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
496 void __asan_register_globals(struct kasan_global *globals, size_t size);
497 void __asan_unregister_globals(struct kasan_global *globals, size_t size);
498 void __asan_handle_no_return(void);
499 void __asan_alloca_poison(unsigned long addr, size_t size);
500 void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
501
502 void __asan_load1(unsigned long addr);
503 void __asan_store1(unsigned long addr);
504 void __asan_load2(unsigned long addr);
505 void __asan_store2(unsigned long addr);
506 void __asan_load4(unsigned long addr);
507 void __asan_store4(unsigned long addr);
508 void __asan_load8(unsigned long addr);
509 void __asan_store8(unsigned long addr);
510 void __asan_load16(unsigned long addr);
511 void __asan_store16(unsigned long addr);
512 void __asan_loadN(unsigned long addr, size_t size);
513 void __asan_storeN(unsigned long addr, size_t size);
514
515 void __asan_load1_noabort(unsigned long addr);
516 void __asan_store1_noabort(unsigned long addr);
517 void __asan_load2_noabort(unsigned long addr);
518 void __asan_store2_noabort(unsigned long addr);
519 void __asan_load4_noabort(unsigned long addr);
520 void __asan_store4_noabort(unsigned long addr);
521 void __asan_load8_noabort(unsigned long addr);
522 void __asan_store8_noabort(unsigned long addr);
523 void __asan_load16_noabort(unsigned long addr);
524 void __asan_store16_noabort(unsigned long addr);
525 void __asan_loadN_noabort(unsigned long addr, size_t size);
526 void __asan_storeN_noabort(unsigned long addr, size_t size);
527
528 void __asan_report_load1_noabort(unsigned long addr);
529 void __asan_report_store1_noabort(unsigned long addr);
530 void __asan_report_load2_noabort(unsigned long addr);
531 void __asan_report_store2_noabort(unsigned long addr);
532 void __asan_report_load4_noabort(unsigned long addr);
533 void __asan_report_store4_noabort(unsigned long addr);
534 void __asan_report_load8_noabort(unsigned long addr);
535 void __asan_report_store8_noabort(unsigned long addr);
536 void __asan_report_load16_noabort(unsigned long addr);
537 void __asan_report_store16_noabort(unsigned long addr);
538 void __asan_report_load_n_noabort(unsigned long addr, size_t size);
539 void __asan_report_store_n_noabort(unsigned long addr, size_t size);
540
541 void __asan_set_shadow_00(const void *addr, size_t size);
542 void __asan_set_shadow_f1(const void *addr, size_t size);
543 void __asan_set_shadow_f2(const void *addr, size_t size);
544 void __asan_set_shadow_f3(const void *addr, size_t size);
545 void __asan_set_shadow_f5(const void *addr, size_t size);
546 void __asan_set_shadow_f8(const void *addr, size_t size);
547
548 void __hwasan_load1_noabort(unsigned long addr);
549 void __hwasan_store1_noabort(unsigned long addr);
550 void __hwasan_load2_noabort(unsigned long addr);
551 void __hwasan_store2_noabort(unsigned long addr);
552 void __hwasan_load4_noabort(unsigned long addr);
553 void __hwasan_store4_noabort(unsigned long addr);
554 void __hwasan_load8_noabort(unsigned long addr);
555 void __hwasan_store8_noabort(unsigned long addr);
556 void __hwasan_load16_noabort(unsigned long addr);
557 void __hwasan_store16_noabort(unsigned long addr);
558 void __hwasan_loadN_noabort(unsigned long addr, size_t size);
559 void __hwasan_storeN_noabort(unsigned long addr, size_t size);
560
561 void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);
562
563 #endif
564