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