diff options
Diffstat (limited to 'mm/kasan/kasan.h')
| -rw-r--r-- | mm/kasan/kasan.h | 125 |
1 files changed, 77 insertions, 48 deletions
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 2e973b36fe07..fc9169a54766 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -48,6 +48,7 @@ DECLARE_PER_CPU(long, kasan_page_alloc_skip); static inline bool kasan_vmalloc_enabled(void) { + /* Static branch is never enabled with CONFIG_KASAN_VMALLOC disabled. */ return static_branch_likely(&kasan_flag_vmalloc); } @@ -81,6 +82,11 @@ static inline bool kasan_sample_page_alloc(unsigned int order) #else /* CONFIG_KASAN_HW_TAGS */ +static inline bool kasan_vmalloc_enabled(void) +{ + return IS_ENABLED(CONFIG_KASAN_VMALLOC); +} + static inline bool kasan_async_fault_possible(void) { return false; @@ -100,21 +106,21 @@ static inline bool kasan_sample_page_alloc(unsigned int order) #ifdef CONFIG_KASAN_GENERIC -/* Generic KASAN uses per-object metadata to store stack traces. */ +/* + * Generic KASAN uses per-object metadata to store alloc and free stack traces + * and the quarantine link. + */ static inline bool kasan_requires_meta(void) { - /* - * Technically, Generic KASAN always collects stack traces right now. - * However, let's use kasan_stack_collection_enabled() in case the - * kasan.stacktrace command-line argument is changed to affect - * Generic KASAN. - */ - return kasan_stack_collection_enabled(); + return true; } #else /* CONFIG_KASAN_GENERIC */ -/* Tag-based KASAN modes do not use per-object metadata. */ +/* + * Tag-based KASAN modes do not use per-object metadata: they use the stack + * ring to store alloc and free stack traces and do not use qurantine. + */ static inline bool kasan_requires_meta(void) { return false; @@ -149,7 +155,7 @@ static inline bool kasan_requires_meta(void) #ifdef CONFIG_KASAN_GENERIC -#define KASAN_SLAB_FREETRACK 0xFA /* freed slab object with free track */ +#define KASAN_SLAB_FREE_META 0xFA /* freed slab object with free meta */ #define KASAN_GLOBAL_REDZONE 0xF9 /* redzone for global variable */ /* Stack redzone shadow values. Compiler ABI, do not change. */ @@ -187,6 +193,10 @@ static inline bool kasan_requires_meta(void) struct kasan_track { u32 pid; depot_stack_handle_t stack; +#ifdef CONFIG_KASAN_EXTRA_INFO + u64 cpu:20; + u64 timestamp:44; +#endif /* CONFIG_KASAN_EXTRA_INFO */ }; enum kasan_report_type { @@ -242,6 +252,15 @@ struct kasan_global { #ifdef CONFIG_KASAN_GENERIC +/* + * Alloc meta contains the allocation-related information about a slab object. + * Alloc meta is saved when an object is allocated and is kept until either the + * object returns to the slab freelist (leaves quarantine for quarantined + * objects or gets freed for the non-quarantined ones) or reallocated via + * krealloc or through a mempool. + * Alloc meta is stored inside of the object's redzone. + * Alloc meta is considered valid whenever it contains non-zero data. + */ struct kasan_alloc_meta { struct kasan_track alloc_track; /* Free track is stored in kasan_free_meta. */ @@ -260,8 +279,12 @@ struct qlist_node { #define KASAN_NO_FREE_META INT_MAX /* - * Free meta is only used by Generic mode while the object is in quarantine. - * After that, slab allocator stores the freelist pointer in the object. + * Free meta contains the freeing-related information about a slab object. + * Free meta is only kept for quarantined objects and for mempool objects until + * the object gets allocated again. + * Free meta is stored within the object's memory. + * Free meta is considered valid whenever the value of the shadow byte that + * corresponds to the first 8 bytes of the object is KASAN_SLAB_FREE_META. */ struct kasan_free_meta { struct qlist_node quarantine_link; @@ -275,8 +298,7 @@ struct kasan_free_meta { struct kasan_stack_ring_entry { void *ptr; size_t size; - u32 pid; - depot_stack_handle_t stack; + struct kasan_track track; bool is_free; }; @@ -291,17 +313,27 @@ struct kasan_stack_ring { #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) +static __always_inline bool addr_in_shadow(const void *addr) +{ + return addr >= (void *)KASAN_SHADOW_START && + addr < (void *)KASAN_SHADOW_END; +} + +#ifndef kasan_shadow_to_mem static inline const void *kasan_shadow_to_mem(const void *shadow_addr) { return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT); } +#endif +#ifndef addr_has_metadata static __always_inline bool addr_has_metadata(const void *addr) { return (kasan_reset_tag(addr) >= kasan_shadow_to_mem((void *)KASAN_SHADOW_START)); } +#endif /** * kasan_check_range - Check memory region, and report if invalid access. @@ -353,24 +385,23 @@ void kasan_report_invalid_free(void *object, unsigned long ip, enum kasan_report struct slab *kasan_addr_to_slab(const void *addr); #ifdef CONFIG_KASAN_GENERIC -void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size); -void kasan_init_object_meta(struct kmem_cache *cache, const void *object); struct kasan_alloc_meta *kasan_get_alloc_meta(struct kmem_cache *cache, const void *object); struct kasan_free_meta *kasan_get_free_meta(struct kmem_cache *cache, const void *object); +void kasan_init_object_meta(struct kmem_cache *cache, const void *object); #else -static inline void kasan_init_cache_meta(struct kmem_cache *cache, unsigned int *size) { } static inline void kasan_init_object_meta(struct kmem_cache *cache, const void *object) { } #endif -depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc); -void kasan_set_track(struct kasan_track *track, gfp_t flags); +depot_stack_handle_t kasan_save_stack(gfp_t flags, depot_flags_t depot_flags); +void kasan_set_track(struct kasan_track *track, depot_stack_handle_t stack); +void kasan_save_track(struct kasan_track *track, gfp_t flags); void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags); + void kasan_save_free_info(struct kmem_cache *cache, void *object); -#if defined(CONFIG_KASAN_GENERIC) && \ - (defined(CONFIG_SLAB) || defined(CONFIG_SLUB)) +#ifdef CONFIG_KASAN_GENERIC bool kasan_quarantine_put(struct kmem_cache *cache, void *object); void kasan_quarantine_reduce(void); void kasan_quarantine_remove_cache(struct kmem_cache *cache); @@ -401,6 +432,7 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag) #define hw_suppress_tag_checks_start() arch_suppress_tag_checks_start() #define hw_suppress_tag_checks_stop() arch_suppress_tag_checks_stop() #define hw_force_async_tag_fault() arch_force_async_tag_fault() +#define hw_enable_tag_checks_write_only() arch_enable_tag_checks_write_only() #define hw_get_random_tag() arch_get_random_tag() #define hw_get_mem_tag(addr) arch_get_mem_tag(addr) #define hw_set_mem_tag_range(addr, size, tag, init) \ @@ -421,11 +453,17 @@ void __init kasan_init_tags(void); #if defined(CONFIG_KASAN_HW_TAGS) && IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) void kasan_force_async_fault(void); +bool kasan_write_only_enabled(void); #else /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */ static inline void kasan_force_async_fault(void) { } +static inline bool kasan_write_only_enabled(void) +{ + return false; +} + #endif /* CONFIG_KASAN_HW_TAGS && CONFIG_KASAN_KUNIT_TEST */ #ifdef CONFIG_KASAN_SW_TAGS @@ -440,35 +478,23 @@ static inline u8 kasan_random_tag(void) { return 0; } static inline void kasan_poison(const void *addr, size_t size, u8 value, bool init) { - addr = kasan_reset_tag(addr); - - /* Skip KFENCE memory if called explicitly outside of sl*b. */ - if (is_kfence_address(addr)) - return; - if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) return; if (WARN_ON(size & KASAN_GRANULE_MASK)) return; - hw_set_mem_tag_range((void *)addr, size, value, init); + hw_set_mem_tag_range(kasan_reset_tag(addr), size, value, init); } static inline void kasan_unpoison(const void *addr, size_t size, bool init) { u8 tag = get_tag(addr); - addr = kasan_reset_tag(addr); - - /* Skip KFENCE memory if called explicitly outside of sl*b. */ - if (is_kfence_address(addr)) - return; - if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) return; size = round_up(size, KASAN_GRANULE_SIZE); - hw_set_mem_tag_range((void *)addr, size, tag, init); + hw_set_mem_tag_range(kasan_reset_tag(addr), size, tag, init); } static inline bool kasan_byte_accessible(const void *addr) @@ -483,20 +509,18 @@ static inline bool kasan_byte_accessible(const void *addr) /** * kasan_poison - mark the memory range as inaccessible - * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE - * @size - range size, must be aligned to KASAN_GRANULE_SIZE - * @value - value that's written to metadata for the range - * @init - whether to initialize the memory range (only for hardware tag-based) - * - * The size gets aligned to KASAN_GRANULE_SIZE before marking the range. + * @addr: range start address, must be aligned to KASAN_GRANULE_SIZE + * @size: range size, must be aligned to KASAN_GRANULE_SIZE + * @value: value that's written to metadata for the range + * @init: whether to initialize the memory range (only for hardware tag-based) */ void kasan_poison(const void *addr, size_t size, u8 value, bool init); /** * kasan_unpoison - mark the memory range as accessible - * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE - * @size - range size, can be unaligned - * @init - whether to initialize the memory range (only for hardware tag-based) + * @addr: range start address, must be aligned to KASAN_GRANULE_SIZE + * @size: range size, can be unaligned + * @init: whether to initialize the memory range (only for hardware tag-based) * * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before * marking the range. @@ -514,8 +538,8 @@ bool kasan_byte_accessible(const void *addr); /** * kasan_poison_last_granule - mark the last granule of the memory range as * inaccessible - * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE - * @size - range size + * @address: range start address, must be aligned to KASAN_GRANULE_SIZE + * @size: range size * * This function is only available for the generic mode, as it's the only mode * that has partially poisoned memory granules. @@ -539,6 +563,12 @@ static inline bool kasan_arch_is_ready(void) { return true; } void kasan_kunit_test_suite_start(void); void kasan_kunit_test_suite_end(void); +#ifdef CONFIG_RUST +char kasan_test_rust_uaf(void); +#else +static inline char kasan_test_rust_uaf(void) { return '\0'; } +#endif + #else /* CONFIG_KASAN_KUNIT_TEST */ static inline void kasan_kunit_test_suite_start(void) { } @@ -546,7 +576,7 @@ static inline void kasan_kunit_test_suite_end(void) { } #endif /* CONFIG_KASAN_KUNIT_TEST */ -#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) || IS_ENABLED(CONFIG_KASAN_MODULE_TEST) +#if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) bool kasan_save_enable_multi_shot(void); void kasan_restore_multi_shot(bool enabled); @@ -558,7 +588,6 @@ void kasan_restore_multi_shot(bool enabled); * code. Declared here to avoid warnings about missing declarations. */ -asmlinkage void kasan_unpoison_task_stack_below(const void *watermark); void __asan_register_globals(void *globals, ssize_t size); void __asan_unregister_globals(void *globals, ssize_t size); void __asan_handle_no_return(void); |