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