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