On Sat, Apr 18, 2020 at 5:18 AM 'David Gow' via kasan-dev kasan-dev@googlegroups.com wrote:

From: Patricia Alfonso trishalfonso@google.com

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@google.com Reviewed-by: Dmitry Vyukov dvyukov@google.com Reviewed-by: Brendan Higgins brendanhiggins@google.com Signed-off-by: David Gow davidgow@google.com

Reviewed-by: Andrey Konovalov andreyknvl@google.com

---

lib/Kconfig.kasan | 18 +- lib/Makefile | 3 +- lib/test_kasan.c | 637 ++++++++++++++++------------------------ lib/test_kasan_module.c | 76 +++++ 4 files changed, 343 insertions(+), 391 deletions(-) create mode 100644 lib/test_kasan_module.c

diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index 81f5464ea9e1..53063dee3f81 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -158,10 +158,18 @@ 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-compatible tests of KASAN bug detection capabilities"
  

•   depends on KASAN && KUNIT
    help
  

•     This is a test module doing various nasty things like
  

•     out of bounds accesses, use after free. It is useful for testing
  

•     This is a KUnit test suite doing various nasty things like
  

•     out of bounds and use after free accesses. It is useful for testing
      kernel debugging features like KASAN.
  

+config TEST_KASAN_MODULE

•   tristate "KUnit-incompatible tests of KASAN bug detection capabilities"
  

•   depends on m && KASAN
  

•   help
  

•     This is a part of the KASAN test suite that is incompatible with
  

•     KUnit. Currently includes tests that do bad copy_from/to_user
  

•     accesses.
  

diff --git a/lib/Makefile b/lib/Makefile index 685aee60de1d..361f438c066a 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 a44d3f8a499c..3153bb62dcfd 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -5,8 +5,6 @@

• Author: Andrey Ryabinin a.ryabinin@samsung.com

*/

-#define pr_fmt(fmt) "kasan test: %s " fmt, __func__

#include <linux/bitops.h> #include <linux/delay.h> #include <linux/kasan.h> @@ -65,399 +63,327 @@ static void kasan_test_exit(struct kunit *test) fail_data.report_found); \ } while (0)

-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.");
  

•           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_memmove_invalid_size(void) +static void kmalloc_memmove_invalid_size(struct kunit *test) { char *ptr; size_t size = 64; volatile size_t invalid_size = -2;

•   pr_info("invalid size in memmove\n");
    ptr = kmalloc(size, GFP_KERNEL);
  

•   if (!ptr) {
  

•           pr_err("Allocation failed\n");
  

•           return;
  

•   }
  

•   KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
  
    memset((char *)ptr, 0, 64);
  

•   memmove((char *)ptr, (char *)ptr + 4, invalid_size);
  

•   KUNIT_EXPECT_KASAN_FAIL(test,
  

•           memmove((char *)ptr, (char *)ptr + 4, invalid_size));
    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; @@ -465,12 +391,8 @@ 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.
  

@@ -490,134 +412,93 @@ 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;
  

•   KUNIT_EXPECT_KASAN_FAIL(test, *(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 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; @@ -625,20 +506,17 @@ 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
  

@@ -649,45 +527,60 @@ 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);
  
  

@@ -698,189 +591,163 @@ 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_memmove_invalid_size();
  

•   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_memmove_invalid_size),
  

•   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@samsung.com
• */

+#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");

2.26.1.301.g55bc3eb7cb9-goog

-- You received this message because you are subscribed to the Google Groups "kasan-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/20200418031833.234942-4-davidgow....

On Sat, Apr 18, 2020 at 5:18 AM 'David Gow' via kasan-dev kasan-dev@googlegroups.com wrote:

From: Patricia Alfonso trishalfonso@google.com

Include documentation on how to test KASAN using CONFIG_TEST_KASAN and CONFIG_TEST_KASAN_USER.

Hi David,

Please update commit message too.

Thanks!

Signed-off-by: Patricia Alfonso trishalfonso@google.com Reviewed-by: Dmitry Vyukov dvyukov@google.com Signed-off-by: David Gow davidgow@google.com

---

Documentation/dev-tools/kasan.rst | 70 +++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+)

diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst index c652d740735d..74fa6aa0f0df 100644 --- a/Documentation/dev-tools/kasan.rst +++ b/Documentation/dev-tools/kasan.rst @@ -281,3 +281,73 @@ unmapped. This will require changes in arch-specific code.

This allows ``VMAP_STACK`` support on x86, and can simplify support of architectures that do not have a fixed module region.

+CONFIG_TEST_KASAN_KUNIT & CONFIG_TEST_KASAN_MODULE +--------------------------------------------------

+``CONFIG_TEST_KASAN_KUNIT`` utilizes the KUnit Test Framework for testing. +This means each test focuses on a small unit of functionality and +there are a few ways these tests can be run.

+Each test will print the KASAN report if an error is detected and then +print the number of the test and the status of the test:

+pass::

•    ok 28 - kmalloc_double_kzfree
  

+or, if kmalloc failed::

•    # kmalloc_large_oob_right: ASSERTION FAILED at lib/test_kasan.c:163
  

•    Expected ptr is not null, but is
  

•    not ok 4 - kmalloc_large_oob_right
  

+or, if a KASAN report was expected, but not found::

•    # kmalloc_double_kzfree: EXPECTATION FAILED at lib/test_kasan.c:629
  

•    Expected kasan_data->report_expected == kasan_data->report_found, but
  

•    kasan_data->report_expected == 1
  

•    kasan_data->report_found == 0
  

•    not ok 28 - kmalloc_double_kzfree
  

+All test statuses are tracked as they run and an overall status will +be printed at the end::

•    ok 1 - kasan_kunit_test
  

+or::

•    not ok 1 - kasan_kunit_test
  

+(1) Loadable Module +~~~~~~~~~~~~~~~~~~~~

+With ``CONFIG_KUNIT`` enabled, ``CONFIG_TEST_KASAN_KUNIT`` can be built as +a loadable module and run on any architecture that supports KASAN +using something like insmod or modprobe.

+(2) Built-In +~~~~~~~~~~~~~

+With ``CONFIG_KUNIT`` built-in, ``CONFIG_TEST_KASAN_KUNIT`` can be built-in +on any architecure that supports KASAN. These and any other KUnit +tests enabled will run and print the results at boot as a late-init +call.

+(3) Using kunit_tool +~~~~~~~~~~~~~~~~~~~~~

+With ``CONFIG_KUNIT`` and ``CONFIG_TEST_KASAN`` built-in, we can also

CONFIG_TEST_KASAN_KUNIT here

+use kunit_tool to see the results of these along with other KUnit +tests in a more readable way. This will not print the KASAN reports +of tests that passed. Use `KUnit documentation https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html`_ for more up-to-date +information on kunit_tool.

+.. _KUnit: https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html

+``CONFIG_TEST_KASAN_MODULE`` is a set of KASAN tests that could not be +converted to KUnit. These tests can be run only as a module with +``CONFIG_TEST_KASAN_MODULE`` built as a loadable module and +``CONFIG_KASAN`` built-in. The type of error expected and the +function being run is printed before the expression expected to give +an error. Then the error is printed, if found, and that test +should be interpretted to pass only if the error was the one expected

+by the test.

2.26.1.301.g55bc3eb7cb9-goog

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On Sat, Apr 18, 2020 at 5:19 AM 'David Gow' via kasan-dev kasan-dev@googlegroups.com wrote:

KASAN errors will currently trigger a panic when panic_on_warn is set. This renders kasan_multishot useless, as further KASAN errors won't be reported if the kernel has already paniced. By making kasan_multishot disable this behaviour for KASAN errors, we can still have the benefits of panic_on_warn for non-KASAN warnings, yet be able to use kasan_multishot.

This is particularly important when running KASAN tests, which need to trigger multiple KASAN errors: previously these would panic the system if panic_on_warn was set, now they can run (and will panic the system should non-KASAN warnings show up).

Signed-off-by: David Gow davidgow@google.com

Reviewed-by: Andrey Konovalov andreyknvl@google.com

---

mm/kasan/report.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 0c206bbf9cb3..79fe23bd4f60 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -94,7 +94,7 @@ static void end_report(unsigned long *flags) pr_err("==================================================================\n"); add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irqrestore(&report_lock, *flags);

•   if (panic_on_warn) {
  

•   if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) {
            /*
             * This thread may hit another WARN() in the panic path.
             * Resetting this prevents additional WARN() from panicking the
  

-- 2.26.1.301.g55bc3eb7cb9-goog

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