Re: [RFC PATCH v2 3/3] KASAN: Port KASAN Tests to KUnit

[Dmitry Vyukov]

On Thu, Mar 19, 2020 at 5:42 PM 'Patricia Alfonso' via kasan-dev
<kasan-dev@xxxxxxxxxxxxxxxx> 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 in UML so those tests are protected inside an
> "#if IS_ENABLED(CONFIG_KASAN_STACK)" so this only runs if stack
> instrumentation is 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          |  13 +-
>  lib/Makefile               |   1 +
>  lib/test_kasan.c           | 606 ++++++++++++++-----------------------
>  lib/test_kasan_copy_user.c |  75 +++++
>  4 files changed, 309 insertions(+), 386 deletions(-)
>  create mode 100644 lib/test_kasan_copy_user.c
>
> diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan
> index 5b54f3c9a741..f026c2e62b1d 100644
> --- a/lib/Kconfig.kasan
> +++ b/lib/Kconfig.kasan
> @@ -159,9 +159,16 @@ config KASAN_VMALLOC
>           stacks), but at the cost of higher memory usage.
>
>  config TEST_KASAN
> -       tristate "Module for testing KASAN for bug detection"
> -       depends on m && KASAN
> +       tristate "KUnit testing KASAN for bug detection"
> +       depends on KASAN && KUNIT=y
>         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_USER
> +       tristate "Module testing KASAN for bug detection on copy user tests"
> +       depends on m && KASAN
> +       help
> +         This is a test module for copy_user_tests because these functions
> +         cannot be tested by KUnit so they must be their own module.
> diff --git a/lib/Makefile b/lib/Makefile
> index 5d64890d6b6a..e0dc4430e405 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -62,6 +62,7 @@ obj-$(CONFIG_TEST_IDA) += test_ida.o
>  obj-$(CONFIG_TEST_KASAN) += test_kasan.o
>  CFLAGS_test_kasan.o += -fno-builtin
>  CFLAGS_test_kasan.o += $(call cc-disable-warning, vla)
> +obj-$(CONFIG_TEST_KASAN_USER) += test_kasan_copy_user.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..c255495e6ce3 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 +23,26 @@
>
>  #include <kunit/test.h>
>
> +#if IS_BUILTIN(CONFIG_KUNIT)

This file is not compiled if KUNIT is not builtin, right? In such this
is not necessary.


>  struct kunit_resource resource;
>  struct kunit_kasan_expectation fail_data;
> +bool multishot;
> +
> +int kasan_multi_shot_init(struct kunit *test)
> +{
> +       /*
> +        * Temporarily enable multi-shot mode. Otherwise, we'd only get a
> +        * report for the first case.
> +        */
> +       multishot = kasan_save_enable_multi_shot();
> +       return 0;
> +}
> +
> +void kasan_multi_shot_exit(struct kunit *test)
> +{
> +       kasan_restore_multi_shot(multishot);
> +}
>
>  #define KUNIT_SET_KASAN_DATA(test) do { \
>         fail_data.report_expected = true; \
> @@ -60,61 +76,44 @@ 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;
> @@ -122,324 +121,253 @@ static noinline void __init kmalloc_pagealloc_oob_right(void)
>         /* 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");
> -               return;
> -       }
> +       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");
> -               return;
> -       }
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
> -       kfree(ptr + 1);
> +       KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
>  }
> -#endif
> +#endif /* CONFIG_SLUB */
>
> -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 +375,8 @@ 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 +396,80 @@ 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)
> +#if (IS_ENABLED(CONFIG_KASAN_STACK))

C checks are generally preferable to preprocessor checks. I.e.

if (IS_ENABLED(CONFIG_KASAN_STACK))
    return;
// I don't know if there is a KUNIT feature of "skipping" a test.

This way this code will be at least compiled in UML builds.

Since UML will be the simplest way to test KASAN after this change,
some people may run just these tests and then this may end up not just
failing but even build broken.


> +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;
> -
> -       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);
> +       char stack_array[10];
> +       volatile int i = 0;
> +       char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
>
> -       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;
> +       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;
> +       KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
>  }
> +#endif /* CONFIG_KASAN_STACK */
>
> -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 +477,17 @@ 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 +498,39 @@ 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)
> -               return;
> +       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)
> -               return;
> +       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)
> -               return;
> +       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
>
>         kfree(ptr);
>
> @@ -680,188 +541,167 @@ 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");
> -
>         /*
>          * 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) {}
> +static void vmalloc_oob(struct kunit *test) {}
>  #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();
> +static struct kunit_case kasan_kunit_test_cases[] = {
> +       KUNIT_CASE(kmalloc_oob_right),
> +       KUNIT_CASE(kmalloc_oob_left),
> +       KUNIT_CASE(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;
> -}
> +       KUNIT_CASE(kmalloc_pagealloc_oob_right),
> +       KUNIT_CASE(kmalloc_pagealloc_uaf),
> +       KUNIT_CASE(kmalloc_pagealloc_invalid_free),
> +#endif /* CONFIG_SLUB */
> +       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),
> +#if (IS_ENABLED(CONFIG_KASAN_STACK))
> +       KUNIT_CASE(kasan_stack_oob), // need stack protection
> +       KUNIT_CASE(kasan_alloca_oob_left),
> +       KUNIT_CASE(kasan_alloca_oob_right),
> +#endif /*CONFIG_KASAN_STACK*/
> +       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_multi_shot_init,
> +       .test_cases = kasan_kunit_test_cases,
> +       .exit = kasan_multi_shot_exit,
> +};
> +
> +kunit_test_suite(kasan_kunit_test_suite);
> +
> +#endif /* BUILTIN(CONFIG_KUNIT) */
>
> -module_init(kmalloc_tests_init);
>  MODULE_LICENSE("GPL");
> diff --git a/lib/test_kasan_copy_user.c b/lib/test_kasan_copy_user.c
> new file mode 100644
> index 000000000000..9523cbc332ec
> --- /dev/null
> +++ b/lib/test_kasan_copy_user.c
> @@ -0,0 +1,75 @@
> +// 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 copy_user_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();
> +
> +       copy_user_test();
> +       kasan_restore_multi_shot(multishot);
> +       return -EAGAIN;
> +}
> +
> +module_init(copy_user_tests_init);
> +MODULE_LICENSE("GPL");
> --
> 2.25.1.696.g5e7596f4ac-goog
>
> --
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