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 #ifdef CONFIG_KASAN_HW_TAGS
11
12 #include <linux/static_key.h>
13 #include "../slab.h"
14
15 DECLARE_STATIC_KEY_TRUE(kasan_flag_vmalloc);
16 DECLARE_STATIC_KEY_TRUE(kasan_flag_stacktrace);
17
18 enum kasan_mode {
19 KASAN_MODE_SYNC,
20 KASAN_MODE_ASYNC,
21 KASAN_MODE_ASYMM,
22 };
23
24 extern enum kasan_mode kasan_mode __ro_after_init;
25
kasan_vmalloc_enabled(void)26 static inline bool kasan_vmalloc_enabled(void)
27 {
28 return static_branch_likely(&kasan_flag_vmalloc);
29 }
30
kasan_stack_collection_enabled(void)31 static inline bool kasan_stack_collection_enabled(void)
32 {
33 return static_branch_unlikely(&kasan_flag_stacktrace);
34 }
35
kasan_async_fault_possible(void)36 static inline bool kasan_async_fault_possible(void)
37 {
38 return kasan_mode == KASAN_MODE_ASYNC || kasan_mode == KASAN_MODE_ASYMM;
39 }
40
kasan_sync_fault_possible(void)41 static inline bool kasan_sync_fault_possible(void)
42 {
43 return kasan_mode == KASAN_MODE_SYNC || kasan_mode == KASAN_MODE_ASYMM;
44 }
45
46 #else
47
kasan_stack_collection_enabled(void)48 static inline bool kasan_stack_collection_enabled(void)
49 {
50 return true;
51 }
52
kasan_async_fault_possible(void)53 static inline bool kasan_async_fault_possible(void)
54 {
55 return false;
56 }
57
kasan_sync_fault_possible(void)58 static inline bool kasan_sync_fault_possible(void)
59 {
60 return true;
61 }
62
63 #endif
64
65 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
66 #define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
67 #else
68 #include <asm/mte-kasan.h>
69 #define KASAN_GRANULE_SIZE MTE_GRANULE_SIZE
70 #endif
71
72 #define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1)
73
74 #define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT)
75
76 #ifdef CONFIG_KASAN_GENERIC
77 #define KASAN_PAGE_FREE 0xFF /* freed page */
78 #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocation */
79 #define KASAN_SLAB_REDZONE 0xFC /* redzone for slab object */
80 #define KASAN_SLAB_FREE 0xFB /* freed slab object */
81 #define KASAN_VMALLOC_INVALID 0xF8 /* inaccessible space in vmap area */
82 #else
83 #define KASAN_PAGE_FREE KASAN_TAG_INVALID
84 #define KASAN_PAGE_REDZONE KASAN_TAG_INVALID
85 #define KASAN_SLAB_REDZONE KASAN_TAG_INVALID
86 #define KASAN_SLAB_FREE KASAN_TAG_INVALID
87 #define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only used for SW_TAGS */
88 #endif
89
90 #ifdef CONFIG_KASAN_GENERIC
91
92 #define KASAN_SLAB_FREETRACK 0xFA /* freed slab object with free track */
93 #define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */
94
95 /* Stack redzone shadow values. Compiler ABI, do not change. */
96 #define KASAN_STACK_LEFT 0xF1
97 #define KASAN_STACK_MID 0xF2
98 #define KASAN_STACK_RIGHT 0xF3
99 #define KASAN_STACK_PARTIAL 0xF4
100
101 /* alloca redzone shadow values. */
102 #define KASAN_ALLOCA_LEFT 0xCA
103 #define KASAN_ALLOCA_RIGHT 0xCB
104
105 /* alloca redzone size. Compiler ABI, do not change. */
106 #define KASAN_ALLOCA_REDZONE_SIZE 32
107
108 /* Stack frame marker. Compiler ABI, do not change. */
109 #define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3
110
111 /* Dummy value to avoid breaking randconfig/all*config builds. */
112 #ifndef KASAN_ABI_VERSION
113 #define KASAN_ABI_VERSION 1
114 #endif
115
116 #endif /* CONFIG_KASAN_GENERIC */
117
118 /* Metadata layout customization. */
119 #define META_BYTES_PER_BLOCK 1
120 #define META_BLOCKS_PER_ROW 16
121 #define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK)
122 #define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE)
123 #define META_ROWS_AROUND_ADDR 2
124
125 enum kasan_report_type {
126 KASAN_REPORT_ACCESS,
127 KASAN_REPORT_INVALID_FREE,
128 };
129
130 struct kasan_report_info {
131 enum kasan_report_type type;
132 void *access_addr;
133 void *first_bad_addr;
134 size_t access_size;
135 bool is_write;
136 unsigned long ip;
137 };
138
139 /* Do not change the struct layout: compiler ABI. */
140 struct kasan_source_location {
141 const char *filename;
142 int line_no;
143 int column_no;
144 };
145
146 /* Do not change the struct layout: compiler ABI. */
147 struct kasan_global {
148 const void *beg; /* Address of the beginning of the global variable. */
149 size_t size; /* Size of the global variable. */
150 size_t size_with_redzone; /* Size of the variable + size of the redzone. 32 bytes aligned. */
151 const void *name;
152 const void *module_name; /* Name of the module where the global variable is declared. */
153 unsigned long has_dynamic_init; /* This is needed for C++. */
154 #if KASAN_ABI_VERSION >= 4
155 struct kasan_source_location *location;
156 #endif
157 #if KASAN_ABI_VERSION >= 5
158 char *odr_indicator;
159 #endif
160 };
161
162 /* Structures for keeping alloc and free tracks. */
163
164 #define KASAN_STACK_DEPTH 64
165
166 struct kasan_track {
167 u32 pid;
168 depot_stack_handle_t stack;
169 };
170
171 #if defined(CONFIG_KASAN_TAGS_IDENTIFY) && defined(CONFIG_KASAN_SW_TAGS)
172 #define KASAN_NR_FREE_STACKS 5
173 #else
174 #define KASAN_NR_FREE_STACKS 1
175 #endif
176
177 struct kasan_alloc_meta {
178 struct kasan_track alloc_track;
179 /* Generic mode stores free track in kasan_free_meta. */
180 #ifdef CONFIG_KASAN_GENERIC
181 depot_stack_handle_t aux_stack[2];
182 #else
183 struct kasan_track free_track[KASAN_NR_FREE_STACKS];
184 #endif
185 #ifdef CONFIG_KASAN_TAGS_IDENTIFY
186 u8 free_pointer_tag[KASAN_NR_FREE_STACKS];
187 u8 free_track_idx;
188 #endif
189 };
190
191 struct qlist_node {
192 struct qlist_node *next;
193 };
194
195 /*
196 * Free meta is stored either in the object itself or in the redzone after the
197 * object. In the former case, free meta offset is 0. In the latter case, the
198 * offset is between 0 and INT_MAX. INT_MAX marks that free meta is not present.
199 */
200 #define KASAN_NO_FREE_META INT_MAX
201
202 /*
203 * Free meta is only used by Generic mode while the object is in quarantine.
204 * After that, slab allocator stores the freelist pointer in the object.
205 */
206 struct kasan_free_meta {
207 #ifdef CONFIG_KASAN_GENERIC
208 struct qlist_node quarantine_link;
209 struct kasan_track free_track;
210 #endif
211 };
212
213 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
214 /* Used in KUnit-compatible KASAN tests. */
215 struct kunit_kasan_status {
216 bool report_found;
217 bool sync_fault;
218 };
219 #endif
220
221 struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache,
222 const void *object);
223 #ifdef CONFIG_KASAN_GENERIC
224 struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache,
225 const void *object);
226 #endif
227
228 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
229
kasan_shadow_to_mem(const void * shadow_addr)230 static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
231 {
232 return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
233 << KASAN_SHADOW_SCALE_SHIFT);
234 }
235
addr_has_metadata(const void * addr)236 static inline bool addr_has_metadata(const void *addr)
237 {
238 return (kasan_reset_tag(addr) >=
239 kasan_shadow_to_mem((void *)KASAN_SHADOW_START));
240 }
241
242 /**
243 * kasan_check_range - Check memory region, and report if invalid access.
244 * @addr: the accessed address
245 * @size: the accessed size
246 * @write: true if access is a write access
247 * @ret_ip: return address
248 * @return: true if access was valid, false if invalid
249 */
250 bool kasan_check_range(unsigned long addr, size_t size, bool write,
251 unsigned long ret_ip);
252
253 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
254
addr_has_metadata(const void * addr)255 static inline bool addr_has_metadata(const void *addr)
256 {
257 return (is_vmalloc_addr(addr) || virt_addr_valid(addr));
258 }
259
260 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */
261
262 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
263 void kasan_print_tags(u8 addr_tag, const void *addr);
264 #else
kasan_print_tags(u8 addr_tag,const void * addr)265 static inline void kasan_print_tags(u8 addr_tag, const void *addr) { }
266 #endif
267
268 void *kasan_find_first_bad_addr(void *addr, size_t size);
269 const char *kasan_get_bug_type(struct kasan_report_info *info);
270 void kasan_metadata_fetch_row(char *buffer, void *row);
271
272 #if defined(CONFIG_KASAN_STACK)
273 void kasan_print_address_stack_frame(const void *addr);
274 #else
kasan_print_address_stack_frame(const void * addr)275 static inline void kasan_print_address_stack_frame(const void *addr) { }
276 #endif
277
278 bool kasan_report(unsigned long addr, size_t size,
279 bool is_write, unsigned long ip);
280 void kasan_report_invalid_free(void *object, unsigned long ip);
281
282 struct page *kasan_addr_to_page(const void *addr);
283 struct slab *kasan_addr_to_slab(const void *addr);
284
285 depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
286 void kasan_set_track(struct kasan_track *track, gfp_t flags);
287 void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag);
288 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
289 void *object, u8 tag);
290
291 #if defined(CONFIG_KASAN_GENERIC) && \
292 (defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
293 bool kasan_quarantine_put(struct kmem_cache *cache, void *object);
294 void kasan_quarantine_reduce(void);
295 void kasan_quarantine_remove_cache(struct kmem_cache *cache);
296 #else
kasan_quarantine_put(struct kmem_cache * cache,void * object)297 static inline bool kasan_quarantine_put(struct kmem_cache *cache, void *object) { return false; }
kasan_quarantine_reduce(void)298 static inline void kasan_quarantine_reduce(void) { }
kasan_quarantine_remove_cache(struct kmem_cache * cache)299 static inline void kasan_quarantine_remove_cache(struct kmem_cache *cache) { }
300 #endif
301
302 #ifndef arch_kasan_set_tag
arch_kasan_set_tag(const void * addr,u8 tag)303 static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
304 {
305 return addr;
306 }
307 #endif
308 #ifndef arch_kasan_get_tag
309 #define arch_kasan_get_tag(addr) 0
310 #endif
311
312 #define set_tag(addr, tag) ((void *)arch_kasan_set_tag((addr), (tag)))
313 #define get_tag(addr) arch_kasan_get_tag(addr)
314
315 #ifdef CONFIG_KASAN_HW_TAGS
316
317 #ifndef arch_enable_tagging_sync
318 #define arch_enable_tagging_sync()
319 #endif
320 #ifndef arch_enable_tagging_async
321 #define arch_enable_tagging_async()
322 #endif
323 #ifndef arch_enable_tagging_asymm
324 #define arch_enable_tagging_asymm()
325 #endif
326 #ifndef arch_force_async_tag_fault
327 #define arch_force_async_tag_fault()
328 #endif
329 #ifndef arch_get_random_tag
330 #define arch_get_random_tag() (0xFF)
331 #endif
332 #ifndef arch_get_mem_tag
333 #define arch_get_mem_tag(addr) (0xFF)
334 #endif
335 #ifndef arch_set_mem_tag_range
336 #define arch_set_mem_tag_range(addr, size, tag, init) ((void *)(addr))
337 #endif
338
339 #define hw_enable_tagging_sync() arch_enable_tagging_sync()
340 #define hw_enable_tagging_async() arch_enable_tagging_async()
341 #define hw_enable_tagging_asymm() arch_enable_tagging_asymm()
342 #define hw_force_async_tag_fault() arch_force_async_tag_fault()
343 #define hw_get_random_tag() arch_get_random_tag()
344 #define hw_get_mem_tag(addr) arch_get_mem_tag(addr)
345 #define hw_set_mem_tag_range(addr, size, tag, init) \
346 arch_set_mem_tag_range((addr), (size), (tag), (init))
347
348 void kasan_enable_tagging(void);
349
350 #else /* CONFIG_KASAN_HW_TAGS */
351
352 #define hw_enable_tagging_sync()
353 #define hw_enable_tagging_async()
354 #define hw_enable_tagging_asymm()
355
kasan_enable_tagging(void)356 static inline void kasan_enable_tagging(void) { }
357
358 #endif /* CONFIG_KASAN_HW_TAGS */
359
360 #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
361
362 void kasan_force_async_fault(void);
363
364 #else /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */
365
kasan_force_async_fault(void)366 static inline void kasan_force_async_fault(void) { }
367
368 #endif /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */
369
370 #ifdef CONFIG_KASAN_SW_TAGS
371 u8 kasan_random_tag(void);
372 #elif defined(CONFIG_KASAN_HW_TAGS)
kasan_random_tag(void)373 static inline u8 kasan_random_tag(void) { return hw_get_random_tag(); }
374 #else
kasan_random_tag(void)375 static inline u8 kasan_random_tag(void) { return 0; }
376 #endif
377
378 #ifdef CONFIG_KASAN_HW_TAGS
379
kasan_poison(const void * addr,size_t size,u8 value,bool init)380 static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init)
381 {
382 addr = kasan_reset_tag(addr);
383
384 /* Skip KFENCE memory if called explicitly outside of sl*b. */
385 if (is_kfence_address(addr))
386 return;
387
388 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
389 return;
390 if (WARN_ON(size & KASAN_GRANULE_MASK))
391 return;
392
393 hw_set_mem_tag_range((void *)addr, size, value, init);
394 }
395
kasan_unpoison(const void * addr,size_t size,bool init)396 static inline void kasan_unpoison(const void *addr, size_t size, bool init)
397 {
398 u8 tag = get_tag(addr);
399
400 addr = kasan_reset_tag(addr);
401
402 /* Skip KFENCE memory if called explicitly outside of sl*b. */
403 if (is_kfence_address(addr))
404 return;
405
406 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK))
407 return;
408 /*
409 * Explicitly initialize the memory with the precise object size to
410 * avoid overwriting the slab redzone. This disables initialization in
411 * the arch code and may thus lead to performance penalty. This penalty
412 * does not affect production builds, as slab redzones are not enabled
413 * there.
414 */
415 if (__slub_debug_enabled() &&
416 init && ((unsigned long)size & KASAN_GRANULE_MASK)) {
417 init = false;
418 memzero_explicit((void *)addr, size);
419 }
420 size = round_up(size, KASAN_GRANULE_SIZE);
421
422 hw_set_mem_tag_range((void *)addr, size, tag, init);
423 }
424
kasan_byte_accessible(const void * addr)425 static inline bool kasan_byte_accessible(const void *addr)
426 {
427 u8 ptr_tag = get_tag(addr);
428 u8 mem_tag = hw_get_mem_tag((void *)addr);
429
430 return ptr_tag == KASAN_TAG_KERNEL || ptr_tag == mem_tag;
431 }
432
433 #else /* CONFIG_KASAN_HW_TAGS */
434
435 /**
436 * kasan_poison - mark the memory range as inaccessible
437 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
438 * @size - range size, must be aligned to KASAN_GRANULE_SIZE
439 * @value - value that's written to metadata for the range
440 * @init - whether to initialize the memory range (only for hardware tag-based)
441 *
442 * The size gets aligned to KASAN_GRANULE_SIZE before marking the range.
443 */
444 void kasan_poison(const void *addr, size_t size, u8 value, bool init);
445
446 /**
447 * kasan_unpoison - mark the memory range as accessible
448 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
449 * @size - range size, can be unaligned
450 * @init - whether to initialize the memory range (only for hardware tag-based)
451 *
452 * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before
453 * marking the range.
454 * For the generic mode, the last granule of the memory range gets partially
455 * unpoisoned based on the @size.
456 */
457 void kasan_unpoison(const void *addr, size_t size, bool init);
458
459 bool kasan_byte_accessible(const void *addr);
460
461 #endif /* CONFIG_KASAN_HW_TAGS */
462
463 #ifdef CONFIG_KASAN_GENERIC
464
465 /**
466 * kasan_poison_last_granule - mark the last granule of the memory range as
467 * inaccessible
468 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE
469 * @size - range size
470 *
471 * This function is only available for the generic mode, as it's the only mode
472 * that has partially poisoned memory granules.
473 */
474 void kasan_poison_last_granule(const void *address, size_t size);
475
476 #else /* CONFIG_KASAN_GENERIC */
477
kasan_poison_last_granule(const void * address,size_t size)478 static inline void kasan_poison_last_granule(const void *address, size_t size) { }
479
480 #endif /* CONFIG_KASAN_GENERIC */
481
482 #ifndef kasan_arch_is_ready
kasan_arch_is_ready(void)483 static inline bool kasan_arch_is_ready(void) { return true; }
484 #elif !defined(CONFIG_KASAN_GENERIC) || !defined(CONFIG_KASAN_OUTLINE)
485 #error kasan_arch_is_ready only works in KASAN generic outline mode!
486 #endif
487
488 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) || IS_ENABLED(CONFIG_KASAN_MODULE_TEST)
489
490 bool kasan_save_enable_multi_shot(void);
491 void kasan_restore_multi_shot(bool enabled);
492
493 #endif
494
495 /*
496 * Exported functions for interfaces called from assembly or from generated
497 * code. Declared here to avoid warnings about missing declarations.
498 */
499
500 asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
501 void __asan_register_globals(struct kasan_global *globals, size_t size);
502 void __asan_unregister_globals(struct kasan_global *globals, size_t size);
503 void __asan_handle_no_return(void);
504 void __asan_alloca_poison(unsigned long addr, size_t size);
505 void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
506
507 void __asan_load1(unsigned long addr);
508 void __asan_store1(unsigned long addr);
509 void __asan_load2(unsigned long addr);
510 void __asan_store2(unsigned long addr);
511 void __asan_load4(unsigned long addr);
512 void __asan_store4(unsigned long addr);
513 void __asan_load8(unsigned long addr);
514 void __asan_store8(unsigned long addr);
515 void __asan_load16(unsigned long addr);
516 void __asan_store16(unsigned long addr);
517 void __asan_loadN(unsigned long addr, size_t size);
518 void __asan_storeN(unsigned long addr, size_t size);
519
520 void __asan_load1_noabort(unsigned long addr);
521 void __asan_store1_noabort(unsigned long addr);
522 void __asan_load2_noabort(unsigned long addr);
523 void __asan_store2_noabort(unsigned long addr);
524 void __asan_load4_noabort(unsigned long addr);
525 void __asan_store4_noabort(unsigned long addr);
526 void __asan_load8_noabort(unsigned long addr);
527 void __asan_store8_noabort(unsigned long addr);
528 void __asan_load16_noabort(unsigned long addr);
529 void __asan_store16_noabort(unsigned long addr);
530 void __asan_loadN_noabort(unsigned long addr, size_t size);
531 void __asan_storeN_noabort(unsigned long addr, size_t size);
532
533 void __asan_report_load1_noabort(unsigned long addr);
534 void __asan_report_store1_noabort(unsigned long addr);
535 void __asan_report_load2_noabort(unsigned long addr);
536 void __asan_report_store2_noabort(unsigned long addr);
537 void __asan_report_load4_noabort(unsigned long addr);
538 void __asan_report_store4_noabort(unsigned long addr);
539 void __asan_report_load8_noabort(unsigned long addr);
540 void __asan_report_store8_noabort(unsigned long addr);
541 void __asan_report_load16_noabort(unsigned long addr);
542 void __asan_report_store16_noabort(unsigned long addr);
543 void __asan_report_load_n_noabort(unsigned long addr, size_t size);
544 void __asan_report_store_n_noabort(unsigned long addr, size_t size);
545
546 void __asan_set_shadow_00(const void *addr, size_t size);
547 void __asan_set_shadow_f1(const void *addr, size_t size);
548 void __asan_set_shadow_f2(const void *addr, size_t size);
549 void __asan_set_shadow_f3(const void *addr, size_t size);
550 void __asan_set_shadow_f5(const void *addr, size_t size);
551 void __asan_set_shadow_f8(const void *addr, size_t size);
552
553 void __hwasan_load1_noabort(unsigned long addr);
554 void __hwasan_store1_noabort(unsigned long addr);
555 void __hwasan_load2_noabort(unsigned long addr);
556 void __hwasan_store2_noabort(unsigned long addr);
557 void __hwasan_load4_noabort(unsigned long addr);
558 void __hwasan_store4_noabort(unsigned long addr);
559 void __hwasan_load8_noabort(unsigned long addr);
560 void __hwasan_store8_noabort(unsigned long addr);
561 void __hwasan_load16_noabort(unsigned long addr);
562 void __hwasan_store16_noabort(unsigned long addr);
563 void __hwasan_loadN_noabort(unsigned long addr, size_t size);
564 void __hwasan_storeN_noabort(unsigned long addr, size_t size);
565
566 void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);
567
568 #endif /* __MM_KASAN_KASAN_H */
569