diff options
Diffstat (limited to 'mm/kasan/kasan.c')
| -rw-r--r-- | mm/kasan/kasan.c | 108 |
1 files changed, 81 insertions, 27 deletions
diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 405bba487df5..e13d911251e7 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -5,7 +5,7 @@ * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> * * Some code borrowed from https://github.com/xairy/kasan-prototype by - * Andrey Konovalov <adech.fo@gmail.com> + * Andrey Konovalov <andreyknvl@gmail.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -489,21 +489,17 @@ void kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags) kasan_kmalloc(cache, object, cache->object_size, flags); } -static void kasan_poison_slab_free(struct kmem_cache *cache, void *object) -{ - unsigned long size = cache->object_size; - unsigned long rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); - - /* RCU slabs could be legally used after free within the RCU period */ - if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU)) - return; - - kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE); -} - -bool kasan_slab_free(struct kmem_cache *cache, void *object) +static bool __kasan_slab_free(struct kmem_cache *cache, void *object, + unsigned long ip, bool quarantine) { s8 shadow_byte; + unsigned long rounded_up_size; + + if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) != + object)) { + kasan_report_invalid_free(object, ip); + return true; + } /* RCU slabs could be legally used after free within the RCU period */ if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU)) @@ -511,14 +507,14 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object) shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object)); if (shadow_byte < 0 || shadow_byte >= KASAN_SHADOW_SCALE_SIZE) { - kasan_report_double_free(cache, object, - __builtin_return_address(1)); + kasan_report_invalid_free(object, ip); return true; } - kasan_poison_slab_free(cache, object); + rounded_up_size = round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE); + kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE); - if (unlikely(!(cache->flags & SLAB_KASAN))) + if (!quarantine || unlikely(!(cache->flags & SLAB_KASAN))) return false; set_track(&get_alloc_info(cache, object)->free_track, GFP_NOWAIT); @@ -526,6 +522,11 @@ bool kasan_slab_free(struct kmem_cache *cache, void *object) return true; } +bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip) +{ + return __kasan_slab_free(cache, object, ip, true); +} + void kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, gfp_t flags) { @@ -589,25 +590,29 @@ void kasan_krealloc(const void *object, size_t size, gfp_t flags) kasan_kmalloc(page->slab_cache, object, size, flags); } -void kasan_poison_kfree(void *ptr) +void kasan_poison_kfree(void *ptr, unsigned long ip) { struct page *page; page = virt_to_head_page(ptr); - if (unlikely(!PageSlab(page))) + if (unlikely(!PageSlab(page))) { + if (ptr != page_address(page)) { + kasan_report_invalid_free(ptr, ip); + return; + } kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page), KASAN_FREE_PAGE); - else - kasan_poison_slab_free(page->slab_cache, ptr); + } else { + __kasan_slab_free(page->slab_cache, ptr, ip, false); + } } -void kasan_kfree_large(const void *ptr) +void kasan_kfree_large(void *ptr, unsigned long ip) { - struct page *page = virt_to_page(ptr); - - kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page), - KASAN_FREE_PAGE); + if (ptr != page_address(virt_to_head_page(ptr))) + kasan_report_invalid_free(ptr, ip); + /* The object will be poisoned by page_alloc. */ } int kasan_module_alloc(void *addr, size_t size) @@ -736,6 +741,55 @@ void __asan_unpoison_stack_memory(const void *addr, size_t size) } EXPORT_SYMBOL(__asan_unpoison_stack_memory); +/* Emitted by compiler to poison alloca()ed objects. */ +void __asan_alloca_poison(unsigned long addr, size_t size) +{ + size_t rounded_up_size = round_up(size, KASAN_SHADOW_SCALE_SIZE); + size_t padding_size = round_up(size, KASAN_ALLOCA_REDZONE_SIZE) - + rounded_up_size; + size_t rounded_down_size = round_down(size, KASAN_SHADOW_SCALE_SIZE); + + const void *left_redzone = (const void *)(addr - + KASAN_ALLOCA_REDZONE_SIZE); + const void *right_redzone = (const void *)(addr + rounded_up_size); + + WARN_ON(!IS_ALIGNED(addr, KASAN_ALLOCA_REDZONE_SIZE)); + + kasan_unpoison_shadow((const void *)(addr + rounded_down_size), + size - rounded_down_size); + kasan_poison_shadow(left_redzone, KASAN_ALLOCA_REDZONE_SIZE, + KASAN_ALLOCA_LEFT); + kasan_poison_shadow(right_redzone, + padding_size + KASAN_ALLOCA_REDZONE_SIZE, + KASAN_ALLOCA_RIGHT); +} +EXPORT_SYMBOL(__asan_alloca_poison); + +/* Emitted by compiler to unpoison alloca()ed areas when the stack unwinds. */ +void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom) +{ + if (unlikely(!stack_top || stack_top > stack_bottom)) + return; + + kasan_unpoison_shadow(stack_top, stack_bottom - stack_top); +} +EXPORT_SYMBOL(__asan_allocas_unpoison); + +/* Emitted by the compiler to [un]poison local variables. */ +#define DEFINE_ASAN_SET_SHADOW(byte) \ + void __asan_set_shadow_##byte(const void *addr, size_t size) \ + { \ + __memset((void *)addr, 0x##byte, size); \ + } \ + EXPORT_SYMBOL(__asan_set_shadow_##byte) + +DEFINE_ASAN_SET_SHADOW(00); +DEFINE_ASAN_SET_SHADOW(f1); +DEFINE_ASAN_SET_SHADOW(f2); +DEFINE_ASAN_SET_SHADOW(f3); +DEFINE_ASAN_SET_SHADOW(f5); +DEFINE_ASAN_SET_SHADOW(f8); + #ifdef CONFIG_MEMORY_HOTPLUG static int __meminit kasan_mem_notifier(struct notifier_block *nb, unsigned long action, void *data) |