diff options
| -rw-r--r-- | lib/test_kasan.c | 29 | ||||
| -rw-r--r-- | mm/kasan/kasan.c | 19 | ||||
| -rw-r--r-- | mm/kasan/kasan.h | 1 | ||||
| -rw-r--r-- | mm/kasan/report.c | 3 |
4 files changed, 52 insertions, 0 deletions
diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 5e51872b3fc1..fbdf87920093 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -20,6 +20,11 @@ #include <linux/uaccess.h> #include <linux/module.h> +/* + * Note: test functions are marked noinline so that their names appear in + * reports. + */ + static noinline void __init kmalloc_oob_right(void) { char *ptr; @@ -411,6 +416,29 @@ static noinline void __init copy_user_test(void) kfree(kmem); } +static noinline void __init use_after_scope_test(void) +{ + volatile char *volatile p; + + pr_info("use-after-scope on int\n"); + { + int local = 0; + + p = (char *)&local; + } + p[0] = 1; + p[3] = 1; + + pr_info("use-after-scope on array\n"); + { + char local[1024] = {0}; + + p = local; + } + p[0] = 1; + p[1023] = 1; +} + static int __init kmalloc_tests_init(void) { kmalloc_oob_right(); @@ -436,6 +464,7 @@ static int __init kmalloc_tests_init(void) kasan_global_oob(); ksize_unpoisons_memory(); copy_user_test(); + use_after_scope_test(); return -EAGAIN; } diff --git a/mm/kasan/kasan.c b/mm/kasan/kasan.c index 70c009741aab..0e9505f66ec1 100644 --- a/mm/kasan/kasan.c +++ b/mm/kasan/kasan.c @@ -764,6 +764,25 @@ EXPORT_SYMBOL(__asan_storeN_noabort); void __asan_handle_no_return(void) {} EXPORT_SYMBOL(__asan_handle_no_return); +/* Emitted by compiler to poison large objects when they go out of scope. */ +void __asan_poison_stack_memory(const void *addr, size_t size) +{ + /* + * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded + * by redzones, so we simply round up size to simplify logic. + */ + kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE), + KASAN_USE_AFTER_SCOPE); +} +EXPORT_SYMBOL(__asan_poison_stack_memory); + +/* Emitted by compiler to unpoison large objects when they go into scope. */ +void __asan_unpoison_stack_memory(const void *addr, size_t size) +{ + kasan_unpoison_shadow(addr, size); +} +EXPORT_SYMBOL(__asan_unpoison_stack_memory); + #ifdef CONFIG_MEMORY_HOTPLUG static int kasan_mem_notifier(struct notifier_block *nb, unsigned long action, void *data) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 03f4545b103d..1c260e6b3b3c 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -21,6 +21,7 @@ #define KASAN_STACK_MID 0xF2 #define KASAN_STACK_RIGHT 0xF3 #define KASAN_STACK_PARTIAL 0xF4 +#define KASAN_USE_AFTER_SCOPE 0xF8 /* Don't break randconfig/all*config builds */ #ifndef KASAN_ABI_VERSION diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 24c1211fe9d5..073325aedc68 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -90,6 +90,9 @@ static void print_error_description(struct kasan_access_info *info) case KASAN_KMALLOC_FREE: bug_type = "use-after-free"; break; + case KASAN_USE_AFTER_SCOPE: + bug_type = "use-after-scope"; + break; } pr_err("BUG: KASAN: %s in %pS at addr %p\n", |