diff --git a/lib/test_kasan.c b/lib/test_kasan.c index ec657105edbf..51b78405bf24 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -579,6 +579,73 @@ static noinline void __init kmem_cache_invalid_free(void) kmem_cache_destroy(cache); } +static noinline void __init kasan_memchr(void) +{ + char *ptr; + size_t size = 24; + + pr_info("out-of-bounds in memchr\n"); + ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); + if (!ptr) + return; + + memchr(ptr, '1', size + 1); + kfree(ptr); +} + +static noinline void __init kasan_memcmp(void) +{ + char *ptr; + size_t size = 24; + int arr[9]; + + pr_info("out-of-bounds in memcmp\n"); + ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); + if (!ptr) + return; + + memset(arr, 0, sizeof(arr)); + memcmp(ptr, arr, size+1); + kfree(ptr); +} + +static noinline void __init kasan_strings(void) +{ + char *ptr; + size_t size = 24; + + pr_info("use-after-free in strchr\n"); + ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO); + if (!ptr) + return; + + kfree(ptr); + + /* + * Try to cause only 1 invalid access (less spam in dmesg). + * For that we need ptr to point to zeroed byte. + * Skip metadata that could be stored in freed object so ptr + * will likely point to zeroed byte. + */ + ptr += 16; + strchr(ptr, '1'); + + pr_info("use-after-free in strrchr\n"); + strrchr(ptr, '1'); + + pr_info("use-after-free in strcmp\n"); + strcmp(ptr, "2"); + + pr_info("use-after-free in strncmp\n"); + strncmp(ptr, "2", 1); + + pr_info("use-after-free in strlen\n"); + strlen(ptr); + + pr_info("use-after-free in strnlen\n"); + strnlen(ptr, 1); +} + static int __init kmalloc_tests_init(void) { /* @@ -618,6 +685,9 @@ static int __init kmalloc_tests_init(void) use_after_scope_test(); kmem_cache_double_free(); kmem_cache_invalid_free(); + kasan_memchr(); + kasan_memcmp(); + kasan_strings(); kasan_restore_multi_shot(multishot);