diff options
| -rw-r--r-- | lib/Kconfig.kasan | 8 | ||||
| -rw-r--r-- | lib/Makefile | 7 | ||||
| -rw-r--r-- | lib/test_kasan.c | 277 |
3 files changed, 289 insertions, 3 deletions
diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index a11ac0234452..4d47d874335c 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -42,4 +42,12 @@ config KASAN_INLINE endchoice +config TEST_KASAN + tristate "Module for testing kasan for bug detection" + depends on m && KASAN + help + This is a test module doing various nasty things like + out of bounds accesses, use after free. It is useful for testing + kernel debugging features like kernel address sanitizer. + endif diff --git a/lib/Makefile b/lib/Makefile index e456defd1021..87eb3bffc283 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -32,12 +32,13 @@ obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o obj-y += hexdump.o obj-$(CONFIG_TEST_HEXDUMP) += test-hexdump.o obj-y += kstrtox.o -obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o -obj-$(CONFIG_TEST_LKM) += test_module.o -obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o obj-$(CONFIG_TEST_BPF) += test_bpf.o obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o +obj-$(CONFIG_TEST_KASAN) += test_kasan.o +obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o +obj-$(CONFIG_TEST_LKM) += test_module.o obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o +obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/test_kasan.c b/lib/test_kasan.c new file mode 100644 index 000000000000..098c08eddfab --- /dev/null +++ b/lib/test_kasan.c @@ -0,0 +1,277 @@ +/* + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <a.ryabinin@samsung.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 + * published by the Free Software Foundation. + * + */ + +#define pr_fmt(fmt) "kasan test: %s " fmt, __func__ + +#include <linux/kernel.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/module.h> + +static noinline void __init kmalloc_oob_right(void) +{ + char *ptr; + size_t size = 123; + + pr_info("out-of-bounds to right\n"); + ptr = kmalloc(size, GFP_KERNEL); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + + ptr[size] = 'x'; + kfree(ptr); +} + +static noinline void __init kmalloc_oob_left(void) +{ + char *ptr; + size_t size = 15; + + pr_info("out-of-bounds to left\n"); + ptr = kmalloc(size, GFP_KERNEL); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + + *ptr = *(ptr - 1); + kfree(ptr); +} + +static noinline void __init kmalloc_node_oob_right(void) +{ + char *ptr; + size_t size = 4096; + + pr_info("kmalloc_node(): out-of-bounds to right\n"); + ptr = kmalloc_node(size, GFP_KERNEL, 0); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + + ptr[size] = 0; + kfree(ptr); +} + +static noinline void __init kmalloc_large_oob_rigth(void) +{ + char *ptr; + size_t size = KMALLOC_MAX_CACHE_SIZE + 10; + + pr_info("kmalloc large allocation: out-of-bounds to right\n"); + ptr = kmalloc(size, GFP_KERNEL); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + + ptr[size] = 0; + kfree(ptr); +} + +static noinline void __init kmalloc_oob_krealloc_more(void) +{ + char *ptr1, *ptr2; + size_t size1 = 17; + size_t size2 = 19; + + pr_info("out-of-bounds after krealloc more\n"); + ptr1 = kmalloc(size1, GFP_KERNEL); + ptr2 = krealloc(ptr1, size2, GFP_KERNEL); + if (!ptr1 || !ptr2) { + pr_err("Allocation failed\n"); + kfree(ptr1); + return; + } + + ptr2[size2] = 'x'; + kfree(ptr2); +} + +static noinline void __init kmalloc_oob_krealloc_less(void) +{ + char *ptr1, *ptr2; + size_t size1 = 17; + size_t size2 = 15; + + pr_info("out-of-bounds after krealloc less\n"); + ptr1 = kmalloc(size1, GFP_KERNEL); + ptr2 = krealloc(ptr1, size2, GFP_KERNEL); + if (!ptr1 || !ptr2) { + pr_err("Allocation failed\n"); + kfree(ptr1); + return; + } + ptr2[size1] = 'x'; + kfree(ptr2); +} + +static noinline void __init kmalloc_oob_16(void) +{ + struct { + u64 words[2]; + } *ptr1, *ptr2; + + pr_info("kmalloc out-of-bounds for 16-bytes access\n"); + ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL); + ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL); + if (!ptr1 || !ptr2) { + pr_err("Allocation failed\n"); + kfree(ptr1); + kfree(ptr2); + return; + } + *ptr1 = *ptr2; + kfree(ptr1); + kfree(ptr2); +} + +static noinline void __init kmalloc_oob_in_memset(void) +{ + char *ptr; + size_t size = 666; + + pr_info("out-of-bounds in memset\n"); + ptr = kmalloc(size, GFP_KERNEL); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + + memset(ptr, 0, size+5); + kfree(ptr); +} + +static noinline void __init kmalloc_uaf(void) +{ + char *ptr; + size_t size = 10; + + pr_info("use-after-free\n"); + ptr = kmalloc(size, GFP_KERNEL); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + + kfree(ptr); + *(ptr + 8) = 'x'; +} + +static noinline void __init kmalloc_uaf_memset(void) +{ + char *ptr; + size_t size = 33; + + pr_info("use-after-free in memset\n"); + ptr = kmalloc(size, GFP_KERNEL); + if (!ptr) { + pr_err("Allocation failed\n"); + return; + } + + kfree(ptr); + memset(ptr, 0, size); +} + +static noinline void __init kmalloc_uaf2(void) +{ + char *ptr1, *ptr2; + size_t size = 43; + + pr_info("use-after-free after another kmalloc\n"); + ptr1 = kmalloc(size, GFP_KERNEL); + if (!ptr1) { + pr_err("Allocation failed\n"); + return; + } + + kfree(ptr1); + ptr2 = kmalloc(size, GFP_KERNEL); + if (!ptr2) { + pr_err("Allocation failed\n"); + return; + } + + ptr1[40] = 'x'; + kfree(ptr2); +} + +static noinline void __init kmem_cache_oob(void) +{ + char *p; + size_t size = 200; + struct kmem_cache *cache = kmem_cache_create("test_cache", + size, 0, + 0, NULL); + if (!cache) { + pr_err("Cache allocation failed\n"); + return; + } + pr_info("out-of-bounds in kmem_cache_alloc\n"); + p = kmem_cache_alloc(cache, GFP_KERNEL); + if (!p) { + pr_err("Allocation failed\n"); + kmem_cache_destroy(cache); + return; + } + + *p = p[size]; + kmem_cache_free(cache, p); + kmem_cache_destroy(cache); +} + +static char global_array[10]; + +static noinline void __init kasan_global_oob(void) +{ + volatile int i = 3; + char *p = &global_array[ARRAY_SIZE(global_array) + i]; + + pr_info("out-of-bounds global variable\n"); + *(volatile char *)p; +} + +static noinline void __init kasan_stack_oob(void) +{ + char stack_array[10]; + volatile int i = 0; + char *p = &stack_array[ARRAY_SIZE(stack_array) + i]; + + pr_info("out-of-bounds on stack\n"); + *(volatile char *)p; +} + +static int __init kmalloc_tests_init(void) +{ + kmalloc_oob_right(); + kmalloc_oob_left(); + kmalloc_node_oob_right(); + kmalloc_large_oob_rigth(); + kmalloc_oob_krealloc_more(); + kmalloc_oob_krealloc_less(); + kmalloc_oob_16(); + kmalloc_oob_in_memset(); + kmalloc_uaf(); + kmalloc_uaf_memset(); + kmalloc_uaf2(); + kmem_cache_oob(); + kasan_stack_oob(); + kasan_global_oob(); + return -EAGAIN; +} + +module_init(kmalloc_tests_init); +MODULE_LICENSE("GPL"); |