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 26 static inline bool kasan_vmalloc_enabled(void) 27 { 28 return static_branch_likely(&kasan_flag_vmalloc); 29 } 30 31 static inline bool kasan_stack_collection_enabled(void) 32 { 33 return static_branch_unlikely(&kasan_flag_stacktrace); 34 } 35 36 static inline bool kasan_async_fault_possible(void) 37 { 38 return kasan_mode == KASAN_MODE_ASYNC || kasan_mode == KASAN_MODE_ASYMM; 39 } 40 41 static inline bool kasan_sync_fault_possible(void) 42 { 43 return kasan_mode == KASAN_MODE_SYNC || kasan_mode == KASAN_MODE_ASYMM; 44 } 45 #else 46 47 static inline bool kasan_stack_collection_enabled(void) 48 { 49 return true; 50 } 51 52 static inline bool kasan_async_fault_possible(void) 53 { 54 return false; 55 } 56 57 static inline bool kasan_sync_fault_possible(void) 58 { 59 return true; 60 } 61 62 #endif 63 64 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 65 #define KASAN_GRANULE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT) 66 #else 67 #include <asm/mte-kasan.h> 68 #define KASAN_GRANULE_SIZE MTE_GRANULE_SIZE 69 #endif 70 71 #define KASAN_GRANULE_MASK (KASAN_GRANULE_SIZE - 1) 72 73 #define KASAN_MEMORY_PER_SHADOW_PAGE (KASAN_GRANULE_SIZE << PAGE_SHIFT) 74 75 #ifdef CONFIG_KASAN_GENERIC 76 #define KASAN_FREE_PAGE 0xFF /* page was freed */ 77 #define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */ 78 #define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */ 79 #define KASAN_KMALLOC_FREE 0xFB /* object was freed (kmem_cache_free/kfree) */ 80 #define KASAN_VMALLOC_INVALID 0xF8 /* unallocated space in vmapped page */ 81 #else 82 #define KASAN_FREE_PAGE KASAN_TAG_INVALID 83 #define KASAN_PAGE_REDZONE KASAN_TAG_INVALID 84 #define KASAN_KMALLOC_REDZONE KASAN_TAG_INVALID 85 #define KASAN_KMALLOC_FREE KASAN_TAG_INVALID 86 #define KASAN_VMALLOC_INVALID KASAN_TAG_INVALID /* only for SW_TAGS */ 87 #endif 88 89 #ifdef CONFIG_KASAN_GENERIC 90 91 #define KASAN_KMALLOC_FREETRACK 0xFA /* object was freed and has free track set */ 92 #define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */ 93 94 /* 95 * Stack redzone shadow values 96 * (Those are compiler's ABI, don't change them) 97 */ 98 #define KASAN_STACK_LEFT 0xF1 99 #define KASAN_STACK_MID 0xF2 100 #define KASAN_STACK_RIGHT 0xF3 101 #define KASAN_STACK_PARTIAL 0xF4 102 103 /* 104 * alloca redzone shadow values 105 */ 106 #define KASAN_ALLOCA_LEFT 0xCA 107 #define KASAN_ALLOCA_RIGHT 0xCB 108 109 #define KASAN_ALLOCA_REDZONE_SIZE 32 110 111 /* 112 * Stack frame marker (compiler ABI). 113 */ 114 #define KASAN_CURRENT_STACK_FRAME_MAGIC 0x41B58AB3 115 116 /* Don't break randconfig/all*config builds */ 117 #ifndef KASAN_ABI_VERSION 118 #define KASAN_ABI_VERSION 1 119 #endif 120 121 #endif /* CONFIG_KASAN_GENERIC */ 122 123 /* Metadata layout customization. */ 124 #define META_BYTES_PER_BLOCK 1 125 #define META_BLOCKS_PER_ROW 16 126 #define META_BYTES_PER_ROW (META_BLOCKS_PER_ROW * META_BYTES_PER_BLOCK) 127 #define META_MEM_BYTES_PER_ROW (META_BYTES_PER_ROW * KASAN_GRANULE_SIZE) 128 #define META_ROWS_AROUND_ADDR 2 129 130 enum kasan_report_type { 131 KASAN_REPORT_ACCESS, 132 KASAN_REPORT_INVALID_FREE, 133 }; 134 135 struct kasan_report_info { 136 enum kasan_report_type type; 137 void *access_addr; 138 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 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) 224 /* Used in KUnit-compatible KASAN tests. */ 225 struct kunit_kasan_status { 226 bool report_found; 227 bool sync_fault; 228 }; 229 #endif 230 231 struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache, 232 const void *object); 233 #ifdef CONFIG_KASAN_GENERIC 234 struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache, 235 const void *object); 236 #endif 237 238 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) 239 240 static inline const void *kasan_shadow_to_mem(const void *shadow_addr) 241 { 242 return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET) 243 << KASAN_SHADOW_SCALE_SHIFT); 244 } 245 246 static inline bool addr_has_metadata(const void *addr) 247 { 248 return (kasan_reset_tag(addr) >= 249 kasan_shadow_to_mem((void *)KASAN_SHADOW_START)); 250 } 251 252 /** 253 * kasan_check_range - Check memory region, and report if invalid access. 254 * @addr: the accessed address 255 * @size: the accessed size 256 * @write: true if access is a write access 257 * @ret_ip: return address 258 * @return: true if access was valid, false if invalid 259 */ 260 bool kasan_check_range(unsigned long addr, size_t size, bool write, 261 unsigned long ret_ip); 262 263 #else /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ 264 265 static inline bool addr_has_metadata(const void *addr) 266 { 267 return (is_vmalloc_addr(addr) || virt_addr_valid(addr)); 268 } 269 270 #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ 271 272 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) 273 void kasan_print_tags(u8 addr_tag, const void *addr); 274 #else 275 static inline void kasan_print_tags(u8 addr_tag, const void *addr) { } 276 #endif 277 278 void *kasan_find_first_bad_addr(void *addr, size_t size); 279 const char *kasan_get_bug_type(struct kasan_report_info *info); 280 void kasan_metadata_fetch_row(char *buffer, void *row); 281 282 #if defined(CONFIG_KASAN_STACK) 283 void kasan_print_address_stack_frame(const void *addr); 284 #else 285 static inline void kasan_print_address_stack_frame(const void *addr) { } 286 #endif 287 288 bool kasan_report(unsigned long addr, size_t size, 289 bool is_write, unsigned long ip); 290 void kasan_report_invalid_free(void *object, unsigned long ip); 291 292 struct page *kasan_addr_to_page(const void *addr); 293 struct slab *kasan_addr_to_slab(const void *addr); 294 295 depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc); 296 void kasan_set_track(struct kasan_track *track, gfp_t flags); 297 void kasan_set_free_info(struct kmem_cache *cache, void *object, u8 tag); 298 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache, 299 void *object, u8 tag); 300 301 #if defined(CONFIG_KASAN_GENERIC) && \ 302 (defined(CONFIG_SLAB) || defined(CONFIG_SLUB)) 303 bool kasan_quarantine_put(struct kmem_cache *cache, void *object); 304 void kasan_quarantine_reduce(void); 305 void kasan_quarantine_remove_cache(struct kmem_cache *cache); 306 #else 307 static inline bool kasan_quarantine_put(struct kmem_cache *cache, void *object) { return false; } 308 static inline void kasan_quarantine_reduce(void) { } 309 static inline void kasan_quarantine_remove_cache(struct kmem_cache *cache) { } 310 #endif 311 312 #ifndef arch_kasan_set_tag 313 static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) 314 { 315 return addr; 316 } 317 #endif 318 #ifndef arch_kasan_get_tag 319 #define arch_kasan_get_tag(addr) 0 320 #endif 321 322 #define set_tag(addr, tag) ((void *)arch_kasan_set_tag((addr), (tag))) 323 #define get_tag(addr) arch_kasan_get_tag(addr) 324 325 #ifdef CONFIG_KASAN_HW_TAGS 326 327 #ifndef arch_enable_tagging_sync 328 #define arch_enable_tagging_sync() 329 #endif 330 #ifndef arch_enable_tagging_async 331 #define arch_enable_tagging_async() 332 #endif 333 #ifndef arch_enable_tagging_asymm 334 #define arch_enable_tagging_asymm() 335 #endif 336 #ifndef arch_force_async_tag_fault 337 #define arch_force_async_tag_fault() 338 #endif 339 #ifndef arch_get_random_tag 340 #define arch_get_random_tag() (0xFF) 341 #endif 342 #ifndef arch_get_mem_tag 343 #define arch_get_mem_tag(addr) (0xFF) 344 #endif 345 #ifndef arch_set_mem_tag_range 346 #define arch_set_mem_tag_range(addr, size, tag, init) ((void *)(addr)) 347 #endif 348 349 #define hw_enable_tagging_sync() arch_enable_tagging_sync() 350 #define hw_enable_tagging_async() arch_enable_tagging_async() 351 #define hw_enable_tagging_asymm() arch_enable_tagging_asymm() 352 #define hw_force_async_tag_fault() arch_force_async_tag_fault() 353 #define hw_get_random_tag() arch_get_random_tag() 354 #define hw_get_mem_tag(addr) arch_get_mem_tag(addr) 355 #define hw_set_mem_tag_range(addr, size, tag, init) \ 356 arch_set_mem_tag_range((addr), (size), (tag), (init)) 357 358 #else /* CONFIG_KASAN_HW_TAGS */ 359 360 #define hw_enable_tagging_sync() 361 #define hw_enable_tagging_async() 362 #define hw_enable_tagging_asymm() 363 364 #endif /* CONFIG_KASAN_HW_TAGS */ 365 366 #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) 367 368 void kasan_enable_tagging(void); 369 void kasan_force_async_fault(void); 370 371 #else /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */ 372 373 static inline void kasan_enable_tagging(void) { } 374 static inline void kasan_force_async_fault(void) { } 375 376 #endif /* CONFIG_KASAN_HW_TAGS || CONFIG_KASAN_KUNIT_TEST */ 377 378 #ifdef CONFIG_KASAN_SW_TAGS 379 u8 kasan_random_tag(void); 380 #elif defined(CONFIG_KASAN_HW_TAGS) 381 static inline u8 kasan_random_tag(void) { return hw_get_random_tag(); } 382 #else 383 static inline u8 kasan_random_tag(void) { return 0; } 384 #endif 385 386 #ifdef CONFIG_KASAN_HW_TAGS 387 388 static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init) 389 { 390 addr = kasan_reset_tag(addr); 391 392 /* Skip KFENCE memory if called explicitly outside of sl*b. */ 393 if (is_kfence_address(addr)) 394 return; 395 396 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) 397 return; 398 if (WARN_ON(size & KASAN_GRANULE_MASK)) 399 return; 400 401 hw_set_mem_tag_range((void *)addr, size, value, init); 402 } 403 404 static inline void kasan_unpoison(const void *addr, size_t size, bool init) 405 { 406 u8 tag = get_tag(addr); 407 408 addr = kasan_reset_tag(addr); 409 410 /* Skip KFENCE memory if called explicitly outside of sl*b. */ 411 if (is_kfence_address(addr)) 412 return; 413 414 if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) 415 return; 416 /* 417 * Explicitly initialize the memory with the precise object size to 418 * avoid overwriting the SLAB redzone. This disables initialization in 419 * the arch code and may thus lead to performance penalty. The penalty 420 * is accepted since SLAB redzones aren't enabled in production builds. 421 */ 422 if (__slub_debug_enabled() && 423 init && ((unsigned long)size & KASAN_GRANULE_MASK)) { 424 init = false; 425 memzero_explicit((void *)addr, size); 426 } 427 size = round_up(size, KASAN_GRANULE_SIZE); 428 429 hw_set_mem_tag_range((void *)addr, size, tag, init); 430 } 431 432 static inline bool kasan_byte_accessible(const void *addr) 433 { 434 u8 ptr_tag = get_tag(addr); 435 u8 mem_tag = hw_get_mem_tag((void *)addr); 436 437 return ptr_tag == KASAN_TAG_KERNEL || ptr_tag == mem_tag; 438 } 439 440 #else /* CONFIG_KASAN_HW_TAGS */ 441 442 /** 443 * kasan_poison - mark the memory range as inaccessible 444 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE 445 * @size - range size, must be aligned to KASAN_GRANULE_SIZE 446 * @value - value that's written to metadata for the range 447 * @init - whether to initialize the memory range (only for hardware tag-based) 448 * 449 * The size gets aligned to KASAN_GRANULE_SIZE before marking the range. 450 */ 451 void kasan_poison(const void *addr, size_t size, u8 value, bool init); 452 453 /** 454 * kasan_unpoison - mark the memory range as accessible 455 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE 456 * @size - range size, can be unaligned 457 * @init - whether to initialize the memory range (only for hardware tag-based) 458 * 459 * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before 460 * marking the range. 461 * For the generic mode, the last granule of the memory range gets partially 462 * unpoisoned based on the @size. 463 */ 464 void kasan_unpoison(const void *addr, size_t size, bool init); 465 466 bool kasan_byte_accessible(const void *addr); 467 468 #endif /* CONFIG_KASAN_HW_TAGS */ 469 470 #ifdef CONFIG_KASAN_GENERIC 471 472 /** 473 * kasan_poison_last_granule - mark the last granule of the memory range as 474 * inaccessible 475 * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE 476 * @size - range size 477 * 478 * This function is only available for the generic mode, as it's the only mode 479 * that has partially poisoned memory granules. 480 */ 481 void kasan_poison_last_granule(const void *address, size_t size); 482 483 #else /* CONFIG_KASAN_GENERIC */ 484 485 static inline void kasan_poison_last_granule(const void *address, size_t size) { } 486 487 #endif /* CONFIG_KASAN_GENERIC */ 488 489 #ifndef kasan_arch_is_ready 490 static inline bool kasan_arch_is_ready(void) { return true; } 491 #elif !defined(CONFIG_KASAN_GENERIC) || !defined(CONFIG_KASAN_OUTLINE) 492 #error kasan_arch_is_ready only works in KASAN generic outline mode! 493 #endif 494 495 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) || IS_ENABLED(CONFIG_KASAN_MODULE_TEST) 496 497 bool kasan_save_enable_multi_shot(void); 498 void kasan_restore_multi_shot(bool enabled); 499 500 #endif 501 502 /* 503 * Exported functions for interfaces called from assembly or from generated 504 * code. Declarations here to avoid warning about missing declarations. 505 */ 506 asmlinkage void kasan_unpoison_task_stack_below(const void *watermark); 507 void __asan_register_globals(struct kasan_global *globals, size_t size); 508 void __asan_unregister_globals(struct kasan_global *globals, size_t size); 509 void __asan_handle_no_return(void); 510 void __asan_alloca_poison(unsigned long addr, size_t size); 511 void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom); 512 513 void __asan_load1(unsigned long addr); 514 void __asan_store1(unsigned long addr); 515 void __asan_load2(unsigned long addr); 516 void __asan_store2(unsigned long addr); 517 void __asan_load4(unsigned long addr); 518 void __asan_store4(unsigned long addr); 519 void __asan_load8(unsigned long addr); 520 void __asan_store8(unsigned long addr); 521 void __asan_load16(unsigned long addr); 522 void __asan_store16(unsigned long addr); 523 void __asan_loadN(unsigned long addr, size_t size); 524 void __asan_storeN(unsigned long addr, size_t size); 525 526 void __asan_load1_noabort(unsigned long addr); 527 void __asan_store1_noabort(unsigned long addr); 528 void __asan_load2_noabort(unsigned long addr); 529 void __asan_store2_noabort(unsigned long addr); 530 void __asan_load4_noabort(unsigned long addr); 531 void __asan_store4_noabort(unsigned long addr); 532 void __asan_load8_noabort(unsigned long addr); 533 void __asan_store8_noabort(unsigned long addr); 534 void __asan_load16_noabort(unsigned long addr); 535 void __asan_store16_noabort(unsigned long addr); 536 void __asan_loadN_noabort(unsigned long addr, size_t size); 537 void __asan_storeN_noabort(unsigned long addr, size_t size); 538 539 void __asan_report_load1_noabort(unsigned long addr); 540 void __asan_report_store1_noabort(unsigned long addr); 541 void __asan_report_load2_noabort(unsigned long addr); 542 void __asan_report_store2_noabort(unsigned long addr); 543 void __asan_report_load4_noabort(unsigned long addr); 544 void __asan_report_store4_noabort(unsigned long addr); 545 void __asan_report_load8_noabort(unsigned long addr); 546 void __asan_report_store8_noabort(unsigned long addr); 547 void __asan_report_load16_noabort(unsigned long addr); 548 void __asan_report_store16_noabort(unsigned long addr); 549 void __asan_report_load_n_noabort(unsigned long addr, size_t size); 550 void __asan_report_store_n_noabort(unsigned long addr, size_t size); 551 552 void __asan_set_shadow_00(const void *addr, size_t size); 553 void __asan_set_shadow_f1(const void *addr, size_t size); 554 void __asan_set_shadow_f2(const void *addr, size_t size); 555 void __asan_set_shadow_f3(const void *addr, size_t size); 556 void __asan_set_shadow_f5(const void *addr, size_t size); 557 void __asan_set_shadow_f8(const void *addr, size_t size); 558 559 void __hwasan_load1_noabort(unsigned long addr); 560 void __hwasan_store1_noabort(unsigned long addr); 561 void __hwasan_load2_noabort(unsigned long addr); 562 void __hwasan_store2_noabort(unsigned long addr); 563 void __hwasan_load4_noabort(unsigned long addr); 564 void __hwasan_store4_noabort(unsigned long addr); 565 void __hwasan_load8_noabort(unsigned long addr); 566 void __hwasan_store8_noabort(unsigned long addr); 567 void __hwasan_load16_noabort(unsigned long addr); 568 void __hwasan_store16_noabort(unsigned long addr); 569 void __hwasan_loadN_noabort(unsigned long addr, size_t size); 570 void __hwasan_storeN_noabort(unsigned long addr, size_t size); 571 572 void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size); 573 574 #endif 575