On Tue, Apr 14, 2020 at 5:17 AM 'David Gow' via kasan-dev kasan-dev@googlegroups.com wrote:

From: Patricia Alfonso trishalfonso@google.com

Integrate KASAN into KUnit testing framework. - Fail tests when KASAN reports an error that is not expected - Use KUNIT_EXPECT_KASAN_FAIL to expect a KASAN error in KASAN tests - Expected KASAN reports pass tests and are still printed when run without kunit_tool (kunit_tool still bypasses the report due to the test passing) - KUnit struct in current task used to keep track of the current test from KASAN code - Also make KASAN no-longer panic when panic_on_warn and kasan_multi_shot are enabled (as multi-shot does nothing otherwise)

Make use of "[PATCH v3 kunit-next 1/2] kunit: generalize kunit_resource API beyond allocated resources" and "[PATCH v3 kunit-next 2/2] kunit: add support for named resources" from Alan Maguire [1] - A named resource is added to a test when a KASAN report is expected - This resource contains a struct for kasan_data containing booleans representing if a KASAN report is expected and if a KASAN report is found

[1] (https://lore.kernel.org/linux-kselftest/1583251361-12748-1-git-send-email-al...)

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

---

include/kunit/test.h | 5 +++++ include/linux/kasan.h | 6 ++++++ lib/kunit/test.c | 13 ++++++++----- lib/test_kasan.c | 44 +++++++++++++++++++++++++++++++++++++++---- mm/kasan/report.c | 34 ++++++++++++++++++++++++++++++++- 5 files changed, 92 insertions(+), 10 deletions(-)

diff --git a/include/kunit/test.h b/include/kunit/test.h index ac59d18e6bab..1dc3d118f64b 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -225,6 +225,11 @@ struct kunit { struct list_head resources; /* Protected by lock. */ };

+static inline void kunit_set_failure(struct kunit *test) +{

•   WRITE_ONCE(test->success, false);
  

+}

void kunit_init_test(struct kunit *test, const char *name, char *log);

int kunit_run_tests(struct kunit_suite *suite); diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 5cde9e7c2664..148eaef3e003 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -14,6 +14,12 @@ struct task_struct; #include <asm/kasan.h> #include <asm/pgtable.h>

+/* kasan_data struct is used in KUnit tests for KASAN expected failures */ +struct kunit_kasan_expectation {

•   bool report_expected;
  

•   bool report_found;
  

+};

extern unsigned char kasan_early_shadow_page[PAGE_SIZE]; extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE]; extern pmd_t kasan_early_shadow_pmd[PTRS_PER_PMD]; diff --git a/lib/kunit/test.c b/lib/kunit/test.c index 2cb7c6220a00..030a3281591e 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -10,16 +10,12 @@ #include <linux/kernel.h> #include <linux/kref.h> #include <linux/sched/debug.h> +#include <linux/sched.h>

#include "debugfs.h" #include "string-stream.h" #include "try-catch-impl.h"

-static void kunit_set_failure(struct kunit *test) -{

•   WRITE_ONCE(test->success, false);
  

-}

static void kunit_print_tap_version(void) { static bool kunit_has_printed_tap_version; @@ -288,6 +284,10 @@ static void kunit_try_run_case(void *data) struct kunit_suite *suite = ctx->suite; struct kunit_case *test_case = ctx->test_case;

+#if (IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT))

•   current->kunit_test = test;
  

+#endif /* IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT) */

•   /*
     * kunit_run_case_internal may encounter a fatal error; if it does,
     * abort will be called, this thread will exit, and finally the parent
  

@@ -603,6 +603,9 @@ void kunit_cleanup(struct kunit *test) spin_unlock(&test->lock); kunit_remove_resource(test, res); } +#if (IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT))

•   current->kunit_test = NULL;
  

+#endif /* IS_ENABLED(CONFIG_KASAN) && IS_ENABLED(CONFIG_KUNIT)*/ } EXPORT_SYMBOL_GPL(kunit_cleanup);

diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 3872d250ed2c..7b4cb107b387 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -23,12 +23,48 @@

#include <asm/page.h>

-/*

• • Note: test functions are marked noinline so that their names appear in
• • reports.

+#include <kunit/test.h>

+static struct kunit_resource resource; +static struct kunit_kasan_expectation fail_data; +static bool multishot;

+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();
  

•   return 0;
  

+}

+static void kasan_test_exit(struct kunit *test) +{

•   kasan_restore_multi_shot(multishot);
  

+}

+/**

• • KUNIT_EXPECT_KASAN_FAIL() - Causes a test failure when the expression does
• • not cause a KASAN error. This uses a KUnit resource named "kasan_data." Do
• • Do not use this name for a KUnit resource outside here.
• */

+#define KUNIT_EXPECT_KASAN_FAIL(test, condition) do { \

•   fail_data.report_expected = true; \
  

•   fail_data.report_found = false; \
  

•   kunit_add_named_resource(test, \
  

•                           NULL, \
  

•                           NULL, \
  

•                           &resource, \
  

•                           "kasan_data", &fail_data); \
  

•   condition; \
  

•   KUNIT_EXPECT_EQ(test, \
  

•                   fail_data.report_expected, \
  

•                   fail_data.report_found); \
  

+} while (0)

-static noinline void __init kmalloc_oob_right(void) { char *ptr; size_t size = 123; diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 5ef9f24f566b..a58a9f3b7f2c 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -32,6 +32,8 @@

#include <asm/sections.h>

+#include <kunit/test.h>

#include "kasan.h" #include "../slab.h"

@@ -92,7 +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))
            panic("panic_on_warn set ...\n");
  

Please move this change into a separate commit.

With that:

Reviewed-by: Andrey Konovalov andreyknvl@google.com

    kasan_enable_current();

} @@ -455,12 +457,37 @@ static bool report_enabled(void) return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); }

+#if IS_ENABLED(CONFIG_KUNIT) +static void kasan_update_kunit_status(struct kunit *cur_test) +{

•   struct kunit_resource *resource;
  

•   struct kunit_kasan_expectation *kasan_data;
  

•   resource = kunit_find_named_resource(cur_test, "kasan_data");
  

•   if (!resource) {
  

•           kunit_set_failure(cur_test);
  

•           return;
  

•   }
  

•   kasan_data = (struct kunit_kasan_expectation *)resource->data;
  

•   kasan_data->report_found = true;
  

•   kunit_put_resource(resource);
  

+} +#endif /* IS_ENABLED(CONFIG_KUNIT) */

void kasan_report_invalid_free(void *object, unsigned long ip) { unsigned long flags; u8 tag = get_tag(object);

    object = reset_tag(object);

+#if IS_ENABLED(CONFIG_KUNIT)

•   if (current->kunit_test)
  

•           kasan_update_kunit_status(current->kunit_test);
  

+#endif /* IS_ENABLED(CONFIG_KUNIT) */

•   start_report(&flags);
    pr_err("BUG: KASAN: double-free or invalid-free in %pS\n", (void *)ip);
    print_tags(tag, object);
  

@@ -481,6 +508,11 @@ void __kasan_report(unsigned long addr, size_t size, bool is_write, unsigned lon if (likely(!report_enabled())) return;

+#if IS_ENABLED(CONFIG_KUNIT)

•   if (current->kunit_test)
  

•           kasan_update_kunit_status(current->kunit_test);
  

+#endif /* IS_ENABLED(CONFIG_KUNIT) */

•   disable_trace_on_warning();
  
    tagged_addr = (void *)addr;
  

-- 2.26.0.110.g2183baf09c-goog

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On Tue, Apr 14, 2020 at 10:29 PM Andrey Konovalov andreyknvl@google.com wrote:

On Tue, Apr 14, 2020 at 5:17 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

---

lib/Kconfig.kasan | 18 +- lib/Makefile | 3 +- lib/test_kasan.c | 622 ++++++++++++++++------------------------ lib/test_kasan_module.c | 76 +++++ 4 files changed, 337 insertions(+), 382 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 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 7b4cb107b387..801ef7573da2 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> @@ -65,380 +63,311 @@ static void kasan_test_exit(struct kunit *test) fail_data.report_found); \ } while (0)

+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_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__);
  

Any reason why this is a kunit_err() instead of KUNIT_ASSERT_NOT_ERR_OR_NULL()? It seems inconsistent to use KUNIT_ASSERT_NOT_ERR_OR_NULL() for kmalloc() and kmem_cache_create(), but not for kmem_cache_alloc(). Unless there's a reason for it.

This was because we need to clean up the kmem_cache before the test ends. KUNIT_ASSERT_NOT_ERR_OR_NULL() would kill the test immediately, before the kmem_cache_destroy() line could execute.

There are other things we could do to make this a bit more consistent though: we could use IS_ERR_OR_NULL() rather than just checking !, or we could set up the kmem_cache as a kunit resource, which would automatically be cleaned up. For a simple test like this, though, it may be overkill.

...

            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; @@ -446,12 +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.
  

@@ -471,134 +396,93 @@ 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__);
  

Same here.

...

            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; @@ -606,20 +490,17 @@ 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__);
  

And here.

As above, this is due to needing to clean up the kmem_cache.

...

            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
  

@@ -630,45 +511,60 @@ 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
  

Wrong comment style here and below. Please use scripts/checkpatch.pl to check your patches.

Huh. Checkpatch didn't pick up on this. I've fixed it (here and below) for the next revision.

...

•   if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
  

•           kunit_info(test,
  

•                   "str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT");
            return;
  

•   }
  
  

•   memchr(ptr, '1', size + 1);
  

•   ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
  

•   KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
  

•   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);
  
  

@@ -679,188 +575,162 @@ 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@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");

2.26.0.110.g2183baf09c-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/20200414031647.124664-4-davidgow....

Thanks for looking over this (and the other patches). I've made the suggested changes, and will send out a v6 with in the next day or so.

Cheers, -- David

On Tue, Apr 14, 2020 at 5:17 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.

This patch needs to be updated to use the new naming, TEST_KASAN_KUNIT and TEST_KASAN_MODULE.

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..287ba063d9f6 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 & CONFIG_TEST_KASAN_USER +-------------------------------------------

+``CONFIG_TEST_KASAN`` 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`` built-in, ``CONFIG_TEST_KASAN`` 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`` 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 +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_USER`` 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_USER`` 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.

2.26.0.110.g2183baf09c-goog

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