Re: [PATCH v3 3/4] KASAN: Port KASAN Tests to KUnit

From: Dmitry Vyukov
Date: Thu Apr 02 2020 - 06:32:18 EST


On Wed, Apr 1, 2020 at 8:09 PM Patricia Alfonso <trishalfonso@xxxxxxxxxx> wrote:
>
> Transfer all previous tests for KASAN to KUnit so they can be run
> more easily. Using kunit_tool, developers can run these tests with their
> other KUnit tests and see "pass" or "fail" with the appropriate KASAN
> report instead of needing to parse each KASAN report to test KASAN
> functionalities. All KASAN reports are still printed to dmesg.
>
> Stack tests do not work properly when KASAN_STACK is enabled so
> those tests use a check for "if IS_ENABLED(CONFIG_KASAN_STACK)" so they
> only run if stack instrumentation is enabled. If KASAN_STACK is not
> enabled, KUnit will print a statement to let the user know this test
> was not run with KASAN_STACK enabled.
>
> copy_user_test cannot be run in KUnit so there is a separate test file
> for those tests, which can be run as before as a module.
>
> Signed-off-by: Patricia Alfonso <trishalfonso@xxxxxxxxxx>
> ---
> lib/Kconfig.kasan | 15 +-
> lib/Makefile | 3 +-
> lib/test_kasan.c | 657 +++++++++++++++++-----------------------
> lib/test_kasan_module.c | 76 +++++
> 4 files changed, 362 insertions(+), 389 deletions(-)
> create mode 100644 lib/test_kasan_module.c
>
> diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
> index 81f5464ea9e1..c969ceb4586b 100644
> --- a/lib/Kconfig.kasan
> +++ b/lib/Kconfig.kasan
> @@ -158,10 +158,17 @@ config KASAN_VMALLOC
> for KASAN to detect more sorts of errors (and to support vmapped
> stacks), but at the cost of higher memory usage.
>
> -config TEST_KASAN
> - tristate "Module for testing KASAN for bug detection"
> - depends on m && KASAN
> +config TEST_KASAN_KUNIT
> + tristate "KUnit testing KASAN for bug detection"
> + depends on KASAN && KUNIT
> help
> - This is a test module doing various nasty things like
> + This is a test suite doing various nasty things like
> out of bounds accesses, use after free. It is useful for testing
> kernel debugging features like KASAN.
> +
> +config TEST_KASAN_MODULE
> + tristate "Module testing KASAN for bug detection on copy user tests"
> + depends on m && KASAN
> + help
> + This is a test module for functions which cannot be tested by
> + KUnit, like copy_user_tests.
> diff --git a/lib/Makefile b/lib/Makefile
> index 611872c06926..60e125555271 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -59,9 +59,10 @@ obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o
> obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o
> obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o
> obj-$(CONFIG_TEST_IDA) += test_ida.o
> -obj-$(CONFIG_TEST_KASAN) += test_kasan.o
> +obj-$(CONFIG_TEST_KASAN_KUNIT) += test_kasan.o
> CFLAGS_test_kasan.o += -fno-builtin
> CFLAGS_test_kasan.o += $(call cc-disable-warning, vla)
> +obj-$(CONFIG_TEST_KASAN_MODULE) += test_kasan_module.o
> obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o
> CFLAGS_test_ubsan.o += $(call cc-disable-warning, vla)
> UBSAN_SANITIZE_test_ubsan.o := y
> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> index cf73c6bee81b..87f8b4ce244f 100644
> --- a/lib/test_kasan.c
> +++ b/lib/test_kasan.c
> @@ -5,8 +5,6 @@
> * Author: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
> */
>
> -#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
> -
> #include <linux/bitops.h>
> #include <linux/delay.h>
> #include <linux/kasan.h>
> @@ -25,8 +23,33 @@
>
> #include <kunit/test.h>
>
> -struct kunit_resource resource;
> -struct kunit_kasan_expectation fail_data;
> +static struct kunit_resource resource;
> +static struct kunit_kasan_expectation fail_data;
> +static bool multishot;
> +static int orig_panic_on_warn;
> +int panic_on_warn;

This should be 'extern'. But panic_on_warn is already declared in
<linux/kernel.h>, it's better to include it instead, if we don't yet.

With this nit:

Reviewed-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>

> +
> +static int kasan_test_init(struct kunit *test)
> +{
> + /*
> + * Temporarily enable multi-shot mode and set panic_on_warn=0.
> + * Otherwise, we'd only get a report for the first case.
> + */
> + multishot = kasan_save_enable_multi_shot();
> +
> + orig_panic_on_warn = panic_on_warn;
> + panic_on_warn = 0;
> +
> + return 0;
> +}
> +
> +static void kasan_test_exit(struct kunit *test)
> +{
> + kasan_restore_multi_shot(multishot);
> +
> + /* Restore panic_on_warn */
> + panic_on_warn = orig_panic_on_warn;
> +}
>
> #define KUNIT_SET_KASAN_DATA(test) do { \
> fail_data.report_expected = true; \
> @@ -60,386 +83,311 @@ struct kunit_kasan_expectation fail_data;
> KUNIT_DO_EXPECT_KASAN_FAIL(test, condition); \
> } while (0)
>
> -/*
> - * Note: test functions are marked noinline so that their names appear in
> - * reports.
> - */
> -
> -static noinline void __init kmalloc_oob_right(void)
> +static void kmalloc_oob_right(struct kunit *test)
> {
> 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;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - ptr[size] = 'x';
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x');
> kfree(ptr);
> }
>
> -static noinline void __init kmalloc_oob_left(void)
> +static void kmalloc_oob_left(struct kunit *test)
> {
> 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;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - *ptr = *(ptr - 1);
> + KUNIT_EXPECT_KASAN_FAIL(test, *ptr = *(ptr - 1));
> kfree(ptr);
> }
>
> -static noinline void __init kmalloc_node_oob_right(void)
> +static void kmalloc_node_oob_right(struct kunit *test)
> {
> 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;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - ptr[size] = 0;
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
> kfree(ptr);
> }
>
> -#ifdef CONFIG_SLUB
> -static noinline void __init kmalloc_pagealloc_oob_right(void)
> +static void kmalloc_pagealloc_oob_right(struct kunit *test)
> {
> char *ptr;
> size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
>
> + if (!IS_ENABLED(CONFIG_SLUB)) {
> + kunit_info(test, "CONFIG_SLUB is not enabled.");

This is nice.

> + return;
> + }
> +
> /* Allocate a chunk that does not fit into a SLUB cache to trigger
> * the page allocator fallback.
> */
> - pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - ptr[size] = 0;
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
> kfree(ptr);
> }
>
> -static noinline void __init kmalloc_pagealloc_uaf(void)
> +static void kmalloc_pagealloc_uaf(struct kunit *test)
> {
> char *ptr;
> size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
>
> - pr_info("kmalloc pagealloc allocation: use-after-free\n");
> - ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> + if (!IS_ENABLED(CONFIG_SLUB)) {
> + kunit_info(test, "CONFIG_SLUB is not enabled.");
> return;
> }
>
> + ptr = kmalloc(size, GFP_KERNEL);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
> +
> kfree(ptr);
> - ptr[0] = 0;
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
> }
>
> -static noinline void __init kmalloc_pagealloc_invalid_free(void)
> +static void kmalloc_pagealloc_invalid_free(struct kunit *test)
> {
> char *ptr;
> size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
>
> - pr_info("kmalloc pagealloc allocation: invalid-free\n");
> - ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> + if (!IS_ENABLED(CONFIG_SLUB)) {
> + kunit_info(test, "CONFIG_SLUB is not enabled.");
> return;
> }
>
> - kfree(ptr + 1);
> + ptr = kmalloc(size, GFP_KERNEL);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
> +
> + KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
> }
> -#endif
>
> -static noinline void __init kmalloc_large_oob_right(void)
> +static void kmalloc_large_oob_right(struct kunit *test)
> {
> char *ptr;
> size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
> /* Allocate a chunk that is large enough, but still fits into a slab
> * and does not trigger the page allocator fallback in SLUB.
> */
> - pr_info("kmalloc large allocation: out-of-bounds to right\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - ptr[size] = 0;
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
> kfree(ptr);
> }
>
> -static noinline void __init kmalloc_oob_krealloc_more(void)
> +static void kmalloc_oob_krealloc_more(struct kunit *test)
> {
> 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);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
> +
> ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
> - if (!ptr1 || !ptr2) {
> - pr_err("Allocation failed\n");
> - kfree(ptr1);
> - kfree(ptr2);
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
>
> - ptr2[size2] = 'x';
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
> kfree(ptr2);
> }
>
> -static noinline void __init kmalloc_oob_krealloc_less(void)
> +static void kmalloc_oob_krealloc_less(struct kunit *test)
> {
> 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);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
> +
> ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
> - if (!ptr1 || !ptr2) {
> - pr_err("Allocation failed\n");
> - kfree(ptr1);
> - return;
> - }
> - ptr2[size2] = 'x';
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
> +
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');
> kfree(ptr2);
> }
>
> -static noinline void __init kmalloc_oob_16(void)
> +static void kmalloc_oob_16(struct kunit *test)
> {
> struct {
> u64 words[2];
> } *ptr1, *ptr2;
>
> - pr_info("kmalloc out-of-bounds for 16-bytes access\n");
> ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
> +
> ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
> - if (!ptr1 || !ptr2) {
> - pr_err("Allocation failed\n");
> - kfree(ptr1);
> - kfree(ptr2);
> - return;
> - }
> - *ptr1 = *ptr2;
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
> +
> + KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
> kfree(ptr1);
> kfree(ptr2);
> }
>
> -static noinline void __init kmalloc_oob_memset_2(void)
> +static void kmalloc_oob_memset_2(struct kunit *test)
> {
> char *ptr;
> size_t size = 8;
>
> - pr_info("out-of-bounds in memset2\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - memset(ptr+7, 0, 2);
> + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr+7, 0, 2));
> kfree(ptr);
> }
>
> -static noinline void __init kmalloc_oob_memset_4(void)
> +static void kmalloc_oob_memset_4(struct kunit *test)
> {
> char *ptr;
> size_t size = 8;
>
> - pr_info("out-of-bounds in memset4\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - memset(ptr+5, 0, 4);
> + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr+5, 0, 4));
> kfree(ptr);
> }
>
>
> -static noinline void __init kmalloc_oob_memset_8(void)
> +static void kmalloc_oob_memset_8(struct kunit *test)
> {
> char *ptr;
> size_t size = 8;
>
> - pr_info("out-of-bounds in memset8\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - memset(ptr+1, 0, 8);
> + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr+1, 0, 8));
> kfree(ptr);
> }
>
> -static noinline void __init kmalloc_oob_memset_16(void)
> +static void kmalloc_oob_memset_16(struct kunit *test)
> {
> char *ptr;
> size_t size = 16;
>
> - pr_info("out-of-bounds in memset16\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - memset(ptr+1, 0, 16);
> + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr+1, 0, 16));
> kfree(ptr);
> }
>
> -static noinline void __init kmalloc_oob_in_memset(void)
> +static void kmalloc_oob_in_memset(struct kunit *test)
> {
> 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;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - memset(ptr, 0, size+5);
> + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size+5));
> kfree(ptr);
> }
>
> -static noinline void __init kmalloc_uaf(void)
> +static void kmalloc_uaf(struct kunit *test)
> {
> 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;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> kfree(ptr);
> - *(ptr + 8) = 'x';
> + KUNIT_EXPECT_KASAN_FAIL(test, *(ptr + 8) = 'x');
> }
>
> -static noinline void __init kmalloc_uaf_memset(void)
> +static void kmalloc_uaf_memset(struct kunit *test)
> {
> 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;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> kfree(ptr);
> - memset(ptr, 0, size);
> + KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size));
> }
>
> -static noinline void __init kmalloc_uaf2(void)
> +static void kmalloc_uaf2(struct kunit *test)
> {
> 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;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
>
> kfree(ptr1);
> +
> ptr2 = kmalloc(size, GFP_KERNEL);
> - if (!ptr2) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
> +
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr1[40] = 'x');
> + KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
>
> - ptr1[40] = 'x';
> - if (ptr1 == ptr2)
> - pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
> kfree(ptr2);
> }
>
> -static noinline void __init kfree_via_page(void)
> +static void kfree_via_page(struct kunit *test)
> {
> char *ptr;
> size_t size = 8;
> struct page *page;
> unsigned long offset;
>
> - pr_info("invalid-free false positive (via page)\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> page = virt_to_page(ptr);
> offset = offset_in_page(ptr);
> kfree(page_address(page) + offset);
> }
>
> -static noinline void __init kfree_via_phys(void)
> +static void kfree_via_phys(struct kunit *test)
> {
> char *ptr;
> size_t size = 8;
> phys_addr_t phys;
>
> - pr_info("invalid-free false positive (via phys)\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> phys = virt_to_phys(ptr);
> kfree(phys_to_virt(phys));
> }
>
> -static noinline void __init kmem_cache_oob(void)
> +static void kmem_cache_oob(struct kunit *test)
> {
> 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");
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
> p = kmem_cache_alloc(cache, GFP_KERNEL);
> if (!p) {
> - pr_err("Allocation failed\n");
> + kunit_err(test, "Allocation failed: %s\n", __func__);
> kmem_cache_destroy(cache);
> return;
> }
>
> - *p = p[size];
> + KUNIT_EXPECT_KASAN_FAIL(test, *p = p[size]);
> kmem_cache_free(cache, p);
> kmem_cache_destroy(cache);
> }
>
> -static noinline void __init memcg_accounted_kmem_cache(void)
> +static void memcg_accounted_kmem_cache(struct kunit *test)
> {
> int i;
> char *p;
> @@ -447,12 +395,8 @@ static noinline void __init memcg_accounted_kmem_cache(void)
> struct kmem_cache *cache;
>
> cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
> - if (!cache) {
> - pr_err("Cache allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
>
> - pr_info("allocate memcg accounted object\n");
> /*
> * Several allocations with a delay to allow for lazy per memcg kmem
> * cache creation.
> @@ -472,134 +416,93 @@ static noinline void __init memcg_accounted_kmem_cache(void)
>
> static char global_array[10];
>
> -static noinline void __init kasan_global_oob(void)
> +static void kasan_global_oob(struct kunit *test)
> {
> 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;
> + KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
> }
>
> -static noinline void __init ksize_unpoisons_memory(void)
> +static void ksize_unpoisons_memory(struct kunit *test)
> {
> char *ptr;
> size_t size = 123, real_size;
>
> - pr_info("ksize() unpoisons the whole allocated chunk\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
> real_size = ksize(ptr);
> /* This access doesn't trigger an error. */
> ptr[size] = 'x';
> /* This one does. */
> - ptr[real_size] = 'y';
> + KUNIT_EXPECT_KASAN_FAIL(test, ptr[real_size] = 'y');
> kfree(ptr);
> }
>
> -static noinline void __init copy_user_test(void)
> +static void kasan_stack_oob(struct kunit *test)
> {
> - char *kmem;
> - char __user *usermem;
> - size_t size = 10;
> - int unused;
> -
> - kmem = kmalloc(size, GFP_KERNEL);
> - if (!kmem)
> - return;
> + char stack_array[10];
> + volatile int i = 0;
> + char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
>
> - usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
> - PROT_READ | PROT_WRITE | PROT_EXEC,
> - MAP_ANONYMOUS | MAP_PRIVATE, 0);
> - if (IS_ERR(usermem)) {
> - pr_err("Failed to allocate user memory\n");
> - kfree(kmem);
> + if (!IS_ENABLED(CONFIG_KASAN_STACK)) {
> + kunit_info(test, "CONFIG_KASAN_STACK is not enabled");
> return;
> }
>
> - pr_info("out-of-bounds in copy_from_user()\n");
> - unused = copy_from_user(kmem, usermem, size + 1);
> -
> - pr_info("out-of-bounds in copy_to_user()\n");
> - unused = copy_to_user(usermem, kmem, size + 1);
> -
> - pr_info("out-of-bounds in __copy_from_user()\n");
> - unused = __copy_from_user(kmem, usermem, size + 1);
> -
> - pr_info("out-of-bounds in __copy_to_user()\n");
> - unused = __copy_to_user(usermem, kmem, size + 1);
> -
> - pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
> - unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
> -
> - pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
> - unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
> -
> - pr_info("out-of-bounds in strncpy_from_user()\n");
> - unused = strncpy_from_user(kmem, usermem, size + 1);
> -
> - vm_munmap((unsigned long)usermem, PAGE_SIZE);
> - kfree(kmem);
> + KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
> }
>
> -static noinline void __init kasan_alloca_oob_left(void)
> +static void kasan_alloca_oob_left(struct kunit *test)
> {
> volatile int i = 10;
> char alloca_array[i];
> char *p = alloca_array - 1;
>
> - pr_info("out-of-bounds to left on alloca\n");
> - *(volatile char *)p;
> + if (!IS_ENABLED(CONFIG_KASAN_STACK)) {
> + kunit_info(test, "CONFIG_KASAN_STACK is not enabled");
> + return;
> + }
> +
> + KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
> }
>
> -static noinline void __init kasan_alloca_oob_right(void)
> +static void kasan_alloca_oob_right(struct kunit *test)
> {
> volatile int i = 10;
> char alloca_array[i];
> char *p = alloca_array + i;
>
> - pr_info("out-of-bounds to right on alloca\n");
> - *(volatile char *)p;
> + if (!IS_ENABLED(CONFIG_KASAN_STACK)) {
> + kunit_info(test, "CONFIG_KASAN_STACK is not enabled");
> + return;
> + }
> +
> + KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
> }
>
> -static noinline void __init kmem_cache_double_free(void)
> +static void kmem_cache_double_free(struct kunit *test)
> {
> char *p;
> size_t size = 200;
> struct kmem_cache *cache;
>
> cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
> - if (!cache) {
> - pr_err("Cache allocation failed\n");
> - return;
> - }
> - pr_info("double-free on heap object\n");
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
> +
> p = kmem_cache_alloc(cache, GFP_KERNEL);
> if (!p) {
> - pr_err("Allocation failed\n");
> + kunit_err(test, "Allocation failed: %s\n", __func__);
> kmem_cache_destroy(cache);
> return;
> }
>
> kmem_cache_free(cache, p);
> - kmem_cache_free(cache, p);
> + KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p));
> kmem_cache_destroy(cache);
> }
>
> -static noinline void __init kmem_cache_invalid_free(void)
> +static void kmem_cache_invalid_free(struct kunit *test)
> {
> char *p;
> size_t size = 200;
> @@ -607,20 +510,17 @@ static noinline void __init kmem_cache_invalid_free(void)
>
> cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
> NULL);
> - if (!cache) {
> - pr_err("Cache allocation failed\n");
> - return;
> - }
> - pr_info("invalid-free of heap object\n");
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
> +
> p = kmem_cache_alloc(cache, GFP_KERNEL);
> if (!p) {
> - pr_err("Allocation failed\n");
> + kunit_err(test, "Allocation failed: %s\n", __func__);
> kmem_cache_destroy(cache);
> return;
> }
>
> /* Trigger invalid free, the object doesn't get freed */
> - kmem_cache_free(cache, p + 1);
> + KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));
>
> /*
> * Properly free the object to prevent the "Objects remaining in
> @@ -631,45 +531,60 @@ static noinline void __init kmem_cache_invalid_free(void)
> kmem_cache_destroy(cache);
> }
>
> -static noinline void __init kasan_memchr(void)
> +static void kasan_memchr(struct kunit *test)
> {
> char *ptr;
> size_t size = 24;
>
> - pr_info("out-of-bounds in memchr\n");
> - ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> - if (!ptr)
> + // See https://bugzilla.kernel.org/show_bug.cgi?id=206337
> + if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
> + kunit_info(test,
> + "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");
> return;
> + }
> +
> + ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> - memchr(ptr, '1', size + 1);
> + KUNIT_EXPECT_KASAN_FAIL(test, memchr(ptr, '1', size + 1));
> kfree(ptr);
> }
>
> -static noinline void __init kasan_memcmp(void)
> +static void kasan_memcmp(struct kunit *test)
> {
> 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)
> + // See https://bugzilla.kernel.org/show_bug.cgi?id=206337
> + if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
> + kunit_info(test,
> + "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");
> return;
> + }
> +
> + ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> memset(arr, 0, sizeof(arr));
> - memcmp(ptr, arr, size+1);
> + KUNIT_EXPECT_KASAN_FAIL(test, memcmp(ptr, arr, size+1));
> kfree(ptr);
> }
>
> -static noinline void __init kasan_strings(void)
> +static void kasan_strings(struct kunit *test)
> {
> char *ptr;
> size_t size = 24;
>
> - pr_info("use-after-free in strchr\n");
> - ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> - if (!ptr)
> + // See https://bugzilla.kernel.org/show_bug.cgi?id=206337
> + if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
> + kunit_info(test,
> + "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");
> return;
> + }
> +
> + ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> kfree(ptr);
>
> @@ -680,188 +595,162 @@ static noinline void __init kasan_strings(void)
> * will likely point to zeroed byte.
> */
> ptr += 16;
> - strchr(ptr, '1');
> + KUNIT_EXPECT_KASAN_FAIL(test, strchr(ptr, '1'));
>
> - pr_info("use-after-free in strrchr\n");
> - strrchr(ptr, '1');
> + KUNIT_EXPECT_KASAN_FAIL(test, strrchr(ptr, '1'));
>
> - pr_info("use-after-free in strcmp\n");
> - strcmp(ptr, "2");
> + KUNIT_EXPECT_KASAN_FAIL(test, strcmp(ptr, "2"));
>
> - pr_info("use-after-free in strncmp\n");
> - strncmp(ptr, "2", 1);
> + KUNIT_EXPECT_KASAN_FAIL(test, strncmp(ptr, "2", 1));
>
> - pr_info("use-after-free in strlen\n");
> - strlen(ptr);
> + KUNIT_EXPECT_KASAN_FAIL(test, strlen(ptr));
>
> - pr_info("use-after-free in strnlen\n");
> - strnlen(ptr, 1);
> + KUNIT_EXPECT_KASAN_FAIL(test, strnlen(ptr, 1));
> }
>
> -static noinline void __init kasan_bitops(void)
> +static void kasan_bitops(struct kunit *test)
> {
> /*
> * Allocate 1 more byte, which causes kzalloc to round up to 16-bytes;
> * this way we do not actually corrupt other memory.
> */
> long *bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL);
> - if (!bits)
> - return;
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);
>
> /*
> * Below calls try to access bit within allocated memory; however, the
> * below accesses are still out-of-bounds, since bitops are defined to
> * operate on the whole long the bit is in.
> */
> - pr_info("out-of-bounds in set_bit\n");
> - set_bit(BITS_PER_LONG, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test, set_bit(BITS_PER_LONG, bits));
>
> - pr_info("out-of-bounds in __set_bit\n");
> - __set_bit(BITS_PER_LONG, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test, __set_bit(BITS_PER_LONG, bits));
>
> - pr_info("out-of-bounds in clear_bit\n");
> - clear_bit(BITS_PER_LONG, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test, clear_bit(BITS_PER_LONG, bits));
>
> - pr_info("out-of-bounds in __clear_bit\n");
> - __clear_bit(BITS_PER_LONG, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit(BITS_PER_LONG, bits));
>
> - pr_info("out-of-bounds in clear_bit_unlock\n");
> - clear_bit_unlock(BITS_PER_LONG, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test, clear_bit_unlock(BITS_PER_LONG, bits));
>
> - pr_info("out-of-bounds in __clear_bit_unlock\n");
> - __clear_bit_unlock(BITS_PER_LONG, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit_unlock(BITS_PER_LONG, bits));
>
> - pr_info("out-of-bounds in change_bit\n");
> - change_bit(BITS_PER_LONG, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test, change_bit(BITS_PER_LONG, bits));
>
> - pr_info("out-of-bounds in __change_bit\n");
> - __change_bit(BITS_PER_LONG, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test, __change_bit(BITS_PER_LONG, bits));
>
> /*
> * Below calls try to access bit beyond allocated memory.
> */
> - pr_info("out-of-bounds in test_and_set_bit\n");
> - test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> - pr_info("out-of-bounds in __test_and_set_bit\n");
> - __test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + __test_and_set_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> - pr_info("out-of-bounds in test_and_set_bit_lock\n");
> - test_and_set_bit_lock(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + test_and_set_bit_lock(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> - pr_info("out-of-bounds in test_and_clear_bit\n");
> - test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> - pr_info("out-of-bounds in __test_and_clear_bit\n");
> - __test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + __test_and_clear_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> - pr_info("out-of-bounds in test_and_change_bit\n");
> - test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> - pr_info("out-of-bounds in __test_and_change_bit\n");
> - __test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + __test_and_change_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> - pr_info("out-of-bounds in test_bit\n");
> - (void)test_bit(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + (void)test_bit(BITS_PER_LONG + BITS_PER_BYTE, bits));
>
> #if defined(clear_bit_unlock_is_negative_byte)
> - pr_info("out-of-bounds in clear_bit_unlock_is_negative_byte\n");
> - clear_bit_unlock_is_negative_byte(BITS_PER_LONG + BITS_PER_BYTE, bits);
> + KUNIT_EXPECT_KASAN_FAIL(test,
> + clear_bit_unlock_is_negative_byte(BITS_PER_LONG + BITS_PER_BYTE,
> + bits));
> #endif
> kfree(bits);
> }
>
> -static noinline void __init kmalloc_double_kzfree(void)
> +static void kmalloc_double_kzfree(struct kunit *test)
> {
> char *ptr;
> size_t size = 16;
>
> - pr_info("double-free (kzfree)\n");
> ptr = kmalloc(size, GFP_KERNEL);
> - if (!ptr) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> kzfree(ptr);
> - kzfree(ptr);
> + KUNIT_EXPECT_KASAN_FAIL(test, kzfree(ptr));
> }
>
> -#ifdef CONFIG_KASAN_VMALLOC
> -static noinline void __init vmalloc_oob(void)
> +static void vmalloc_oob(struct kunit *test)
> {
> void *area;
>
> - pr_info("vmalloc out-of-bounds\n");
> + if (!IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
> + kunit_info(test, "CONFIG_KASAN_VMALLOC is not enabled.");
> + return;
> + }
>
> /*
> * We have to be careful not to hit the guard page.
> * The MMU will catch that and crash us.
> */
> area = vmalloc(3000);
> - if (!area) {
> - pr_err("Allocation failed\n");
> - return;
> - }
> + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, area);
>
> - ((volatile char *)area)[3100];
> + KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)area)[3100]);
> vfree(area);
> }
> -#else
> -static void __init vmalloc_oob(void) {}
> -#endif
>
> -static int __init kmalloc_tests_init(void)
> -{
> - /*
> - * Temporarily enable multi-shot mode. Otherwise, we'd only get a
> - * report for the first case.
> - */
> - bool multishot = kasan_save_enable_multi_shot();
> -
> - kmalloc_oob_right();
> - kmalloc_oob_left();
> - kmalloc_node_oob_right();
> -#ifdef CONFIG_SLUB
> - kmalloc_pagealloc_oob_right();
> - kmalloc_pagealloc_uaf();
> - kmalloc_pagealloc_invalid_free();
> -#endif
> - kmalloc_large_oob_right();
> - kmalloc_oob_krealloc_more();
> - kmalloc_oob_krealloc_less();
> - kmalloc_oob_16();
> - kmalloc_oob_in_memset();
> - kmalloc_oob_memset_2();
> - kmalloc_oob_memset_4();
> - kmalloc_oob_memset_8();
> - kmalloc_oob_memset_16();
> - kmalloc_uaf();
> - kmalloc_uaf_memset();
> - kmalloc_uaf2();
> - kfree_via_page();
> - kfree_via_phys();
> - kmem_cache_oob();
> - memcg_accounted_kmem_cache();
> - kasan_stack_oob();
> - kasan_global_oob();
> - kasan_alloca_oob_left();
> - kasan_alloca_oob_right();
> - ksize_unpoisons_memory();
> - copy_user_test();
> - kmem_cache_double_free();
> - kmem_cache_invalid_free();
> - kasan_memchr();
> - kasan_memcmp();
> - kasan_strings();
> - kasan_bitops();
> - kmalloc_double_kzfree();
> - vmalloc_oob();
> -
> - kasan_restore_multi_shot(multishot);
> -
> - return -EAGAIN;
> -}
> +static struct kunit_case kasan_kunit_test_cases[] = {
> + KUNIT_CASE(kmalloc_oob_right),
> + KUNIT_CASE(kmalloc_oob_left),
> + KUNIT_CASE(kmalloc_node_oob_right),
> + KUNIT_CASE(kmalloc_pagealloc_oob_right),
> + KUNIT_CASE(kmalloc_pagealloc_uaf),
> + KUNIT_CASE(kmalloc_pagealloc_invalid_free),
> + KUNIT_CASE(kmalloc_large_oob_right),
> + KUNIT_CASE(kmalloc_oob_krealloc_more),
> + KUNIT_CASE(kmalloc_oob_krealloc_less),
> + KUNIT_CASE(kmalloc_oob_16),
> + KUNIT_CASE(kmalloc_oob_in_memset),
> + KUNIT_CASE(kmalloc_oob_memset_2),
> + KUNIT_CASE(kmalloc_oob_memset_4),
> + KUNIT_CASE(kmalloc_oob_memset_8),
> + KUNIT_CASE(kmalloc_oob_memset_16),
> + KUNIT_CASE(kmalloc_uaf),
> + KUNIT_CASE(kmalloc_uaf_memset),
> + KUNIT_CASE(kmalloc_uaf2),
> + KUNIT_CASE(kfree_via_page),
> + KUNIT_CASE(kfree_via_phys),
> + KUNIT_CASE(kmem_cache_oob),
> + KUNIT_CASE(memcg_accounted_kmem_cache),
> + KUNIT_CASE(kasan_global_oob),
> + KUNIT_CASE(kasan_stack_oob),
> + KUNIT_CASE(kasan_alloca_oob_left),
> + KUNIT_CASE(kasan_alloca_oob_right),
> + KUNIT_CASE(ksize_unpoisons_memory),
> + KUNIT_CASE(kmem_cache_double_free),
> + KUNIT_CASE(kmem_cache_invalid_free),
> + KUNIT_CASE(kasan_memchr),
> + KUNIT_CASE(kasan_memcmp),
> + KUNIT_CASE(kasan_strings),
> + KUNIT_CASE(kasan_bitops),
> + KUNIT_CASE(kmalloc_double_kzfree),
> + KUNIT_CASE(vmalloc_oob),
> + {}
> +};
> +
> +static struct kunit_suite kasan_kunit_test_suite = {
> + .name = "kasan_kunit_test",
> + .init = kasan_test_init,
> + .test_cases = kasan_kunit_test_cases,
> + .exit = kasan_test_exit,
> +};
> +
> +kunit_test_suite(kasan_kunit_test_suite);
>
> -module_init(kmalloc_tests_init);
> MODULE_LICENSE("GPL");
> diff --git a/lib/test_kasan_module.c b/lib/test_kasan_module.c
> new file mode 100644
> index 000000000000..87d7e4d8fc31
> --- /dev/null
> +++ b/lib/test_kasan_module.c
> @@ -0,0 +1,76 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + *
> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
> + * Author: Andrey Ryabinin <a.ryabinin@xxxxxxxxxxx>
> + */
> +
> +#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
> +
> +#include <linux/mman.h>
> +#include <linux/module.h>
> +#include <linux/printk.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +
> +static noinline void __init copy_user_test(void)
> +{
> + char *kmem;
> + char __user *usermem;
> + size_t size = 10;
> + int unused;
> +
> + kmem = kmalloc(size, GFP_KERNEL);
> + if (!kmem)
> + return;
> +
> + usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
> + PROT_READ | PROT_WRITE | PROT_EXEC,
> + MAP_ANONYMOUS | MAP_PRIVATE, 0);
> + if (IS_ERR(usermem)) {
> + pr_err("Failed to allocate user memory\n");
> + kfree(kmem);
> + return;
> + }
> +
> + pr_info("out-of-bounds in copy_from_user()\n");
> + unused = copy_from_user(kmem, usermem, size + 1);
> +
> + pr_info("out-of-bounds in copy_to_user()\n");
> + unused = copy_to_user(usermem, kmem, size + 1);
> +
> + pr_info("out-of-bounds in __copy_from_user()\n");
> + unused = __copy_from_user(kmem, usermem, size + 1);
> +
> + pr_info("out-of-bounds in __copy_to_user()\n");
> + unused = __copy_to_user(usermem, kmem, size + 1);
> +
> + pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
> + unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
> +
> + pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
> + unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
> +
> + pr_info("out-of-bounds in strncpy_from_user()\n");
> + unused = strncpy_from_user(kmem, usermem, size + 1);
> +
> + vm_munmap((unsigned long)usermem, PAGE_SIZE);
> + kfree(kmem);
> +}
> +
> +static int __init test_kasan_module_init(void)
> +{
> + /*
> + * Temporarily enable multi-shot mode. Otherwise, we'd only get a
> + * report for the first case.
> + */
> + bool multishot = kasan_save_enable_multi_shot();
> +
> + copy_user_test();
> +
> + kasan_restore_multi_shot(multishot);
> + return -EAGAIN;
> +}
> +
> +module_init(test_kasan_module_init);
> +MODULE_LICENSE("GPL");
> --
> 2.26.0.rc2.310.g2932bb562d-goog
>