diff options
Diffstat (limited to 'mm/kasan/shadow.c')
| -rw-r--r-- | mm/kasan/shadow.c | 83 |
1 files changed, 53 insertions, 30 deletions
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index 7c2c08c55f32..63f43443f5d7 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -13,6 +13,7 @@ #include <linux/init.h> #include <linux/kasan.h> #include <linux/kernel.h> +#include <linux/kfence.h> #include <linux/kmemleak.h> #include <linux/memory.h> #include <linux/mm.h> @@ -27,20 +28,20 @@ bool __kasan_check_read(const volatile void *p, unsigned int size) { - return check_memory_region((unsigned long)p, size, false, _RET_IP_); + return kasan_check_range((unsigned long)p, size, false, _RET_IP_); } EXPORT_SYMBOL(__kasan_check_read); bool __kasan_check_write(const volatile void *p, unsigned int size) { - return check_memory_region((unsigned long)p, size, true, _RET_IP_); + return kasan_check_range((unsigned long)p, size, true, _RET_IP_); } EXPORT_SYMBOL(__kasan_check_write); #undef memset void *memset(void *addr, int c, size_t len) { - if (!check_memory_region((unsigned long)addr, len, true, _RET_IP_)) + if (!kasan_check_range((unsigned long)addr, len, true, _RET_IP_)) return NULL; return __memset(addr, c, len); @@ -50,8 +51,8 @@ void *memset(void *addr, int c, size_t len) #undef memmove void *memmove(void *dest, const void *src, size_t len) { - if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || - !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) + if (!kasan_check_range((unsigned long)src, len, false, _RET_IP_) || + !kasan_check_range((unsigned long)dest, len, true, _RET_IP_)) return NULL; return __memmove(dest, src, len); @@ -61,18 +62,14 @@ void *memmove(void *dest, const void *src, size_t len) #undef memcpy void *memcpy(void *dest, const void *src, size_t len) { - if (!check_memory_region((unsigned long)src, len, false, _RET_IP_) || - !check_memory_region((unsigned long)dest, len, true, _RET_IP_)) + if (!kasan_check_range((unsigned long)src, len, false, _RET_IP_) || + !kasan_check_range((unsigned long)dest, len, true, _RET_IP_)) return NULL; return __memcpy(dest, src, len); } -/* - * Poisons the shadow memory for 'size' bytes starting from 'addr'. - * Memory addresses should be aligned to KASAN_GRANULE_SIZE. - */ -void poison_range(const void *address, size_t size, u8 value) +void kasan_poison(const void *addr, size_t size, u8 value) { void *shadow_start, *shadow_end; @@ -81,36 +78,62 @@ void poison_range(const void *address, size_t size, u8 value) * some of the callers (e.g. kasan_poison_object_data) pass tagged * addresses to this function. */ - address = kasan_reset_tag(address); - size = round_up(size, KASAN_GRANULE_SIZE); + addr = kasan_reset_tag(addr); - shadow_start = kasan_mem_to_shadow(address); - shadow_end = kasan_mem_to_shadow(address + size); + /* 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; + + shadow_start = kasan_mem_to_shadow(addr); + shadow_end = kasan_mem_to_shadow(addr + size); __memset(shadow_start, value, shadow_end - shadow_start); } +EXPORT_SYMBOL(kasan_poison); -void unpoison_range(const void *address, size_t size) +#ifdef CONFIG_KASAN_GENERIC +void kasan_poison_last_granule(const void *addr, size_t size) { - u8 tag = get_tag(address); + if (size & KASAN_GRANULE_MASK) { + u8 *shadow = (u8 *)kasan_mem_to_shadow(addr + size); + *shadow = size & KASAN_GRANULE_MASK; + } +} +#endif + +void kasan_unpoison(const void *addr, size_t size) +{ + u8 tag = get_tag(addr); /* * Perform shadow offset calculation based on untagged address, as * some of the callers (e.g. kasan_unpoison_object_data) pass tagged * addresses to this function. */ - address = kasan_reset_tag(address); + addr = kasan_reset_tag(addr); + + /* + * Skip KFENCE memory if called explicitly outside of sl*b. Also note + * that calls to ksize(), where size is not a multiple of machine-word + * size, would otherwise poison the invalid portion of the word. + */ + if (is_kfence_address(addr)) + return; - poison_range(address, size, tag); + if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) + return; - if (size & KASAN_GRANULE_MASK) { - u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); + /* Unpoison all granules that cover the object. */ + kasan_poison(addr, round_up(size, KASAN_GRANULE_SIZE), tag); - if (IS_ENABLED(CONFIG_KASAN_SW_TAGS)) - *shadow = tag; - else /* CONFIG_KASAN_GENERIC */ - *shadow = size & KASAN_GRANULE_MASK; - } + /* Partially poison the last granule for the generic mode. */ + if (IS_ENABLED(CONFIG_KASAN_GENERIC)) + kasan_poison_last_granule(addr, size); } #ifdef CONFIG_MEMORY_HOTPLUG @@ -286,7 +309,7 @@ int kasan_populate_vmalloc(unsigned long addr, unsigned long size) * // vmalloc() allocates memory * // let a = area->addr * // we reach kasan_populate_vmalloc - * // and call unpoison_range: + * // and call kasan_unpoison: * STORE shadow(a), unpoison_val * ... * STORE shadow(a+99), unpoison_val x = LOAD p @@ -321,7 +344,7 @@ void kasan_poison_vmalloc(const void *start, unsigned long size) return; size = round_up(size, KASAN_GRANULE_SIZE); - poison_range(start, size, KASAN_VMALLOC_INVALID); + kasan_poison(start, size, KASAN_VMALLOC_INVALID); } void kasan_unpoison_vmalloc(const void *start, unsigned long size) @@ -329,7 +352,7 @@ void kasan_unpoison_vmalloc(const void *start, unsigned long size) if (!is_vmalloc_or_module_addr(start)) return; - unpoison_range(start, size); + kasan_unpoison(start, size); } static int kasan_depopulate_vmalloc_pte(pte_t *ptep, unsigned long addr, |