// 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: " fmt

#include <kunit/test.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/mempool.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/random.h>
#include <linux/set_memory.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/tracepoint.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <trace/events/printk.h>

#include <asm/page.h>

#include "kasan.h"

#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)

MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING");

static bool multishot;

/* Fields set based on lines observed in the console. */
static struct {
        bool report_found;
        bool async_fault;
} test_status;

/*
 * Some tests use these global variables to store return values from function
 * calls that could otherwise be eliminated by the compiler as dead code.
 */
static void *volatile kasan_ptr_result;
static volatile int kasan_int_result;

/* Probe for console output: obtains test_status lines of interest. */
static void probe_console(void *ignore, const char *buf, size_t len)
{
        if (strnstr(buf, "BUG: KASAN: ", len))
                WRITE_ONCE(test_status.report_found, true);
        else if (strnstr(buf, "Asynchronous fault: ", len))
                WRITE_ONCE(test_status.async_fault, true);
}

static int kasan_suite_init(struct kunit_suite *suite)
{
        if (!kasan_enabled()) {
                pr_err("Can't run KASAN tests with KASAN disabled");
                return -1;
        }

        /* Stop failing KUnit tests on KASAN reports. */
        kasan_kunit_test_suite_start();

        /*
         * Temporarily enable multi-shot mode. Otherwise, KASAN would only
         * report the first detected bug and panic the kernel if panic_on_warn
         * is enabled.
         */
        multishot = kasan_save_enable_multi_shot();

        register_trace_console(probe_console, NULL);
        return 0;
}

static void kasan_suite_exit(struct kunit_suite *suite)
{
        kasan_kunit_test_suite_end();
        kasan_restore_multi_shot(multishot);
        unregister_trace_console(probe_console, NULL);
        tracepoint_synchronize_unregister();
}

static void kasan_test_exit(struct kunit *test)
{
        KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found));
}

/**
 * KUNIT_EXPECT_KASAN_RESULT - checks whether the executed expression
 * produces a KASAN report; causes a KUnit test failure when the result
 * is different from @fail.
 *
 * @test: Currently executing KUnit test.
 * @expr: Expression to be tested.
 * @expr_str: Expression to be tested encoded as a string.
 * @fail: Whether expression should produce a KASAN report.
 *
 * For hardware tag-based KASAN, when a synchronous tag fault happens, tag
 * checking is auto-disabled. When this happens, this test handler reenables
 * tag checking. As tag checking can be only disabled or enabled per CPU,
 * this handler disables migration (preemption).
 *
 * Since the compiler doesn't see that the expression can change the test_status
 * fields, it can reorder or optimize away the accesses to those fields.
 * Use READ/WRITE_ONCE() for the accesses and compiler barriers around the
 * expression to prevent that.
 *
 * In between KUNIT_EXPECT_KASAN_RESULT checks, test_status.report_found is kept
 * as false. This allows detecting KASAN reports that happen outside of the
 * checks by asserting !test_status.report_found at the start of
 * KUNIT_EXPECT_KASAN_RESULT and in kasan_test_exit.
 */
#define KUNIT_EXPECT_KASAN_RESULT(test, expr, expr_str, fail)           \
do {                                                                    \
        if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&                         \
            kasan_sync_fault_possible())                                \
                migrate_disable();                                      \
        KUNIT_EXPECT_FALSE(test, READ_ONCE(test_status.report_found));  \
        barrier();                                                      \
        expr;                                                           \
        barrier();                                                      \
        if (kasan_async_fault_possible())                               \
                kasan_force_async_fault();                              \
        if (READ_ONCE(test_status.report_found) != fail) {              \
                KUNIT_FAIL(test, KUNIT_SUBTEST_INDENT "KASAN failure"   \
                                "%sexpected in \"" expr_str             \
                                 "\", but %soccurred",                  \
                                (fail ? " " : " not "),         \
                                (test_status.report_found ?             \
                                 "" : "none "));                        \
        }                                                               \
        if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) &&                         \
            kasan_sync_fault_possible()) {                              \
                if (READ_ONCE(test_status.report_found) &&              \
                    !READ_ONCE(test_status.async_fault))                \
                        kasan_enable_hw_tags();                         \
                migrate_enable();                                       \
        }                                                               \
        WRITE_ONCE(test_status.report_found, false);                    \
        WRITE_ONCE(test_status.async_fault, false);                     \
} while (0)

/*
 * KUNIT_EXPECT_KASAN_FAIL - check that the executed expression produces a
 * KASAN report; causes a KUnit test failure otherwise.
 *
 * @test: Currently executing KUnit test.
 * @expr: Expression that must produce a KASAN report.
 */
#define KUNIT_EXPECT_KASAN_FAIL(test, expr)                     \
        KUNIT_EXPECT_KASAN_RESULT(test, expr, #expr, true)

/*
 * KUNIT_EXPECT_KASAN_FAIL_READ - check that the executed expression
 * produces a KASAN report when the write-only mode is not enabled;
 * causes a KUnit test failure otherwise.
 *
 * Note: At the moment, this macro does not check whether the produced
 * KASAN report is a report about a bad read access. It is only intended
 * for checking the write-only KASAN mode functionality without failing
 * KASAN tests.
 *
 * @test: Currently executing KUnit test.
 * @expr: Expression that must only produce a KASAN report
 *        when the write-only mode is not enabled.
 */
#define KUNIT_EXPECT_KASAN_FAIL_READ(test, expr)                        \
        KUNIT_EXPECT_KASAN_RESULT(test, expr, #expr,                    \
                        !kasan_write_only_enabled())                    \

#define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do {                   \
        if (!IS_ENABLED(config))                                        \
                kunit_skip((test), "Test requires " #config "=y");      \
} while (0)

#define KASAN_TEST_NEEDS_CONFIG_OFF(test, config) do {                  \
        if (IS_ENABLED(config))                                         \
                kunit_skip((test), "Test requires " #config "=n");      \
} while (0)

#define KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test) do {               \
        if (IS_ENABLED(CONFIG_KASAN_HW_TAGS))                           \
                break;  /* No compiler instrumentation. */              \
        if (IS_ENABLED(CONFIG_CC_HAS_KASAN_MEMINTRINSIC_PREFIX))        \
                break;  /* Should always be instrumented! */            \
        if (IS_ENABLED(CONFIG_GENERIC_ENTRY))                           \
                kunit_skip((test), "Test requires checked mem*()");     \
} while (0)

static void kmalloc_oob_right(struct kunit *test)
{
        char *ptr;
        size_t size = 128 - KASAN_GRANULE_SIZE - 5;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        /*
         * An unaligned access past the requested kmalloc size.
         * Only generic KASAN can precisely detect these.
         */
        if (IS_ENABLED(CONFIG_KASAN_GENERIC))
                KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x');

        /*
         * An aligned access into the first out-of-bounds granule that falls
         * within the aligned kmalloc object.
         */
        KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + 5] = 'y');

        /* Out-of-bounds access past the aligned kmalloc object. */
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ptr[0] =
                        ptr[size + KASAN_GRANULE_SIZE + 5]);

        kfree(ptr);
}

static void kmalloc_oob_left(struct kunit *test)
{
        char *ptr;
        size_t size = 15;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        KUNIT_EXPECT_KASAN_FAIL_READ(test, *ptr = *(ptr - 1));
        kfree(ptr);
}

static void kmalloc_node_oob_right(struct kunit *test)
{
        char *ptr;
        size_t size = 4096;

        ptr = kmalloc_node(size, GFP_KERNEL, 0);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ptr[0] = ptr[size]);
        kfree(ptr);
}

static void kmalloc_track_caller_oob_right(struct kunit *test)
{
        char *ptr;
        size_t size = 128 - KASAN_GRANULE_SIZE;

        /*
         * Check that KASAN detects out-of-bounds access for object allocated via
         * kmalloc_track_caller().
         */
        ptr = kmalloc_track_caller(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'y');

        kfree(ptr);

        /*
         * Check that KASAN detects out-of-bounds access for object allocated via
         * kmalloc_node_track_caller().
         */
        ptr = kmalloc_node_track_caller(size, GFP_KERNEL, 0);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'y');

        kfree(ptr);
}

/*
 * Check that KASAN detects an out-of-bounds access for a big object allocated
 * via kmalloc(). But not as big as to trigger the page_alloc fallback.
 */
static void kmalloc_big_oob_right(struct kunit *test)
{
        char *ptr;
        size_t size = KMALLOC_MAX_CACHE_SIZE - 256;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
        kfree(ptr);
}

/*
 * The kmalloc_large_* tests below use kmalloc() to allocate a memory chunk
 * that does not fit into the largest slab cache and therefore is allocated via
 * the page_alloc fallback.
 */

static void kmalloc_large_oob_right(struct kunit *test)
{
        char *ptr;
        size_t size = KMALLOC_MAX_CACHE_SIZE + 10;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0);

        kfree(ptr);
}

static void kmalloc_large_uaf(struct kunit *test)
{
        char *ptr;
        size_t size = KMALLOC_MAX_CACHE_SIZE + 10;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
        kfree(ptr);

        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr)[0]);
}

static void kmalloc_large_invalid_free(struct kunit *test)
{
        char *ptr;
        size_t size = KMALLOC_MAX_CACHE_SIZE + 10;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
}

static void page_alloc_oob_right(struct kunit *test)
{
        char *ptr;
        struct page *pages;
        size_t order = 4;
        size_t size = (1UL << (PAGE_SHIFT + order));

        /*
         * With generic KASAN page allocations have no redzones, thus
         * out-of-bounds detection is not guaranteed.
         * See https://bugzilla.kernel.org/show_bug.cgi?id=210503.
         */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);

        pages = alloc_pages(GFP_KERNEL, order);
        ptr = page_address(pages);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        KUNIT_EXPECT_KASAN_FAIL_READ(test, ptr[0] = ptr[size]);
        free_pages((unsigned long)ptr, order);
}

static void page_alloc_uaf(struct kunit *test)
{
        char *ptr;
        struct page *pages;
        size_t order = 4;

        pages = alloc_pages(GFP_KERNEL, order);
        ptr = page_address(pages);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
        free_pages((unsigned long)ptr, order);

        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr)[0]);
}

static void krealloc_more_oob_helper(struct kunit *test,
                                        size_t size1, size_t size2)
{
        char *ptr1, *ptr2;
        size_t middle;

        KUNIT_ASSERT_LT(test, size1, size2);
        middle = size1 + (size2 - size1) / 2;

        ptr1 = kmalloc(size1, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);

        ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);

        /* Suppress -Warray-bounds warnings. */
        OPTIMIZER_HIDE_VAR(ptr2);

        /* All offsets up to size2 must be accessible. */
        ptr2[size1 - 1] = 'x';
        ptr2[size1] = 'x';
        ptr2[middle] = 'x';
        ptr2[size2 - 1] = 'x';

        /* Generic mode is precise, so unaligned size2 must be inaccessible. */
        if (IS_ENABLED(CONFIG_KASAN_GENERIC))
                KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');

        /* For all modes first aligned offset after size2 must be inaccessible. */
        KUNIT_EXPECT_KASAN_FAIL(test,
                ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x');

        kfree(ptr2);
}

static void krealloc_less_oob_helper(struct kunit *test,
                                        size_t size1, size_t size2)
{
        char *ptr1, *ptr2;
        size_t middle;

        KUNIT_ASSERT_LT(test, size2, size1);
        middle = size2 + (size1 - size2) / 2;

        ptr1 = kmalloc(size1, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);

        ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);

        /* Suppress -Warray-bounds warnings. */
        OPTIMIZER_HIDE_VAR(ptr2);

        /* Must be accessible for all modes. */
        ptr2[size2 - 1] = 'x';

        /* Generic mode is precise, so unaligned size2 must be inaccessible. */
        if (IS_ENABLED(CONFIG_KASAN_GENERIC))
                KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size2] = 'x');

        /* For all modes first aligned offset after size2 must be inaccessible. */
        KUNIT_EXPECT_KASAN_FAIL(test,
                ptr2[round_up(size2, KASAN_GRANULE_SIZE)] = 'x');

        /*
         * For all modes all size2, middle, and size1 should land in separate
         * granules and thus the latter two offsets should be inaccessible.
         */
        KUNIT_EXPECT_LE(test, round_up(size2, KASAN_GRANULE_SIZE),
                                round_down(middle, KASAN_GRANULE_SIZE));
        KUNIT_EXPECT_LE(test, round_up(middle, KASAN_GRANULE_SIZE),
                                round_down(size1, KASAN_GRANULE_SIZE));
        KUNIT_EXPECT_KASAN_FAIL(test, ptr2[middle] = 'x');
        KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1 - 1] = 'x');
        KUNIT_EXPECT_KASAN_FAIL(test, ptr2[size1] = 'x');

        kfree(ptr2);
}

static void krealloc_more_oob(struct kunit *test)
{
        krealloc_more_oob_helper(test, 201, 235);
}

static void krealloc_less_oob(struct kunit *test)
{
        krealloc_less_oob_helper(test, 235, 201);
}

static void krealloc_large_more_oob(struct kunit *test)
{
        krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201,
                                        KMALLOC_MAX_CACHE_SIZE + 235);
}

static void krealloc_large_less_oob(struct kunit *test)
{
        krealloc_less_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 235,
                                        KMALLOC_MAX_CACHE_SIZE + 201);
}

/*
 * Check that krealloc() detects a use-after-free, returns NULL,
 * and doesn't unpoison the freed object.
 */
static void krealloc_uaf(struct kunit *test)
{
        char *ptr1, *ptr2;
        int size1 = 201;
        int size2 = 235;

        ptr1 = kmalloc(size1, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
        kfree(ptr1);

        KUNIT_EXPECT_KASAN_FAIL(test, ptr2 = krealloc(ptr1, size2, GFP_KERNEL));
        KUNIT_ASSERT_NULL(test, ptr2);
        KUNIT_EXPECT_KASAN_FAIL_READ(test, *(volatile char *)ptr1);
}

static void kmalloc_oob_16(struct kunit *test)
{
        struct {
                u64 words[2];
        } *ptr1, *ptr2;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        /* This test is specifically crafted for the generic mode. */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);

        /* RELOC_HIDE to prevent gcc from warning about short alloc */
        ptr1 = RELOC_HIDE(kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL), 0);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);

        ptr2 = kmalloc_obj(*ptr2);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);

        OPTIMIZER_HIDE_VAR(ptr1);
        OPTIMIZER_HIDE_VAR(ptr2);
        KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
        kfree(ptr1);
        kfree(ptr2);
}

static void kmalloc_uaf_16(struct kunit *test)
{
        struct {
                u64 words[2];
        } *ptr1, *ptr2;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        ptr1 = kmalloc_obj(*ptr1);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);

        ptr2 = kmalloc_obj(*ptr2);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
        kfree(ptr2);

        KUNIT_EXPECT_KASAN_FAIL_READ(test, *ptr1 = *ptr2);
        kfree(ptr1);
}

/*
 * Note: in the memset tests below, the written range touches both valid and
 * invalid memory. This makes sure that the instrumentation does not only check
 * the starting address but the whole range.
 */

static void kmalloc_oob_memset_2(struct kunit *test)
{
        char *ptr;
        size_t size = 128 - KASAN_GRANULE_SIZE;
        size_t memset_size = 2;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(size);
        OPTIMIZER_HIDE_VAR(memset_size);
        KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, memset_size));
        kfree(ptr);
}

static void kmalloc_oob_memset_4(struct kunit *test)
{
        char *ptr;
        size_t size = 128 - KASAN_GRANULE_SIZE;
        size_t memset_size = 4;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(size);
        OPTIMIZER_HIDE_VAR(memset_size);
        KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, memset_size));
        kfree(ptr);
}

static void kmalloc_oob_memset_8(struct kunit *test)
{
        char *ptr;
        size_t size = 128 - KASAN_GRANULE_SIZE;
        size_t memset_size = 8;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(size);
        OPTIMIZER_HIDE_VAR(memset_size);
        KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, memset_size));
        kfree(ptr);
}

static void kmalloc_oob_memset_16(struct kunit *test)
{
        char *ptr;
        size_t size = 128 - KASAN_GRANULE_SIZE;
        size_t memset_size = 16;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(size);
        OPTIMIZER_HIDE_VAR(memset_size);
        KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, memset_size));
        kfree(ptr);
}

static void kmalloc_oob_in_memset(struct kunit *test)
{
        char *ptr;
        size_t size = 128 - KASAN_GRANULE_SIZE;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(size);
        KUNIT_EXPECT_KASAN_FAIL(test,
                                memset(ptr, 0, size + KASAN_GRANULE_SIZE));
        kfree(ptr);
}

static void kmalloc_memmove_negative_size(struct kunit *test)
{
        char *ptr;
        size_t size = 64;
        size_t invalid_size = -2;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        /*
         * Hardware tag-based mode doesn't check memmove for negative size.
         * As a result, this test introduces a side-effect memory corruption,
         * which can result in a crash.
         */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        memset((char *)ptr, 0, 64);
        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(invalid_size);
        KUNIT_EXPECT_KASAN_FAIL(test,
                memmove((char *)ptr, (char *)ptr + 4, invalid_size));
        kfree(ptr);
}

static void kmalloc_memmove_invalid_size(struct kunit *test)
{
        char *ptr;
        size_t size = 64;
        size_t invalid_size = size;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        memset((char *)ptr, 0, 64);
        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(invalid_size);
        KUNIT_EXPECT_KASAN_FAIL_READ(test,
                        memmove((char *)ptr, (char *)ptr + 4, invalid_size));
        kfree(ptr);
}

static void kmalloc_uaf(struct kunit *test)
{
        char *ptr;
        size_t size = 10;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        kfree(ptr);
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr)[8]);
}

static void kmalloc_uaf_memset(struct kunit *test)
{
        char *ptr;
        size_t size = 33;

        KASAN_TEST_NEEDS_CHECKED_MEMINTRINSICS(test);

        /*
         * Only generic KASAN uses quarantine, which is required to avoid a
         * kernel memory corruption this test causes.
         */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        kfree(ptr);
        KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size));
}

static void kmalloc_uaf2(struct kunit *test)
{
        char *ptr1, *ptr2;
        size_t size = 43;
        int counter = 0;

again:
        ptr1 = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);

        kfree(ptr1);

        ptr2 = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);

        /*
         * For tag-based KASAN ptr1 and ptr2 tags might happen to be the same.
         * Allow up to 16 attempts at generating different tags.
         */
        if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && ptr1 == ptr2 && counter++ < 16) {
                kfree(ptr2);
                goto again;
        }

        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr1)[40]);
        KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);

        kfree(ptr2);
}

/*
 * Check that KASAN detects use-after-free when another object was allocated in
 * the same slot. Relevant for the tag-based modes, which do not use quarantine.
 */
static void kmalloc_uaf3(struct kunit *test)
{
        char *ptr1, *ptr2;
        size_t size = 100;

        /* This test is specifically crafted for tag-based modes. */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);

        ptr1 = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
        kfree(ptr1);

        ptr2 = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
        kfree(ptr2);

        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr1)[8]);
}

static void kasan_atomics_helper(struct kunit *test, void *unsafe, void *safe)
{
        int *i_unsafe = unsafe;

        KUNIT_EXPECT_KASAN_FAIL_READ(test, READ_ONCE(*i_unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, WRITE_ONCE(*i_unsafe, 42));
        KUNIT_EXPECT_KASAN_FAIL_READ(test, smp_load_acquire(i_unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, smp_store_release(i_unsafe, 42));

        KUNIT_EXPECT_KASAN_FAIL_READ(test, atomic_read(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_set(unsafe, 42));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_add(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_sub(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_and(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_andnot(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_or(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_xor(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_xchg(unsafe, 42));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_cmpxchg(unsafe, 21, 42));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_try_cmpxchg(unsafe, safe, 42));
        /*
         * The result of the test below may vary due to garbage values of
         * unsafe in write-only mode.
         * Therefore, skip this test when KASAN is configured in write-only mode.
         */
        if (!kasan_write_only_enabled())
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_try_cmpxchg(safe, unsafe, 42));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_sub_and_test(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_and_test(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_and_test(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_add_negative(42, unsafe));
        /*
         * The result of the test below may vary due to garbage values of
         * unsafe in write-only mode.
         * Therefore, skip this test when KASAN is configured in write-only mode.
         */
        if (!kasan_write_only_enabled()) {
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_add_unless(unsafe, 21, 42));
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_not_zero(unsafe));
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_inc_unless_negative(unsafe));
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_unless_positive(unsafe));
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_dec_if_positive(unsafe));
        }

        KUNIT_EXPECT_KASAN_FAIL_READ(test, atomic_long_read(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_set(unsafe, 42));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_sub(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_and(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_andnot(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_or(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_xor(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_xchg(unsafe, 42));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_cmpxchg(unsafe, 21, 42));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_try_cmpxchg(unsafe, safe, 42));
        /*
         * The result of the test below may vary due to garbage values of
         * unsafe in write-only mode.
         * Therefore, skip this test when KASAN is configured in write-only mode.
         */
        if (!kasan_write_only_enabled())
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_try_cmpxchg(safe, unsafe, 42));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_sub_and_test(42, unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_and_test(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_and_test(unsafe));
        KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add_negative(42, unsafe));
        /*
         * The result of the test below may vary due to garbage values of
         * unsafe in write-only mode.
         * Therefore, skip this test when KASAN is configured in write-only mode.
         */
        if (!kasan_write_only_enabled()) {
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_add_unless(unsafe, 21, 42));
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_not_zero(unsafe));
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_inc_unless_negative(unsafe));
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_unless_positive(unsafe));
                KUNIT_EXPECT_KASAN_FAIL(test, atomic_long_dec_if_positive(unsafe));
        }
}

static void kasan_atomics(struct kunit *test)
{
        void *a1, *a2;

        /*
         * Just as with kasan_bitops_tags(), we allocate 48 bytes of memory such
         * that the following 16 bytes will make up the redzone.
         */
        a1 = kzalloc(48, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, a1);
        a2 = kzalloc_obj(atomic_long_t);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, a2);

        /* Use atomics to access the redzone. */
        kasan_atomics_helper(test, a1 + 48, a2);

        kfree(a1);
        kfree(a2);
}

static void kmalloc_double_kzfree(struct kunit *test)
{
        char *ptr;
        size_t size = 16;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        kfree_sensitive(ptr);
        KUNIT_EXPECT_KASAN_FAIL(test, kfree_sensitive(ptr));
}

/* Check that ksize() does NOT unpoison whole object. */
static void ksize_unpoisons_memory(struct kunit *test)
{
        char *ptr;
        size_t size = 128 - KASAN_GRANULE_SIZE - 5;
        size_t real_size;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        real_size = ksize(ptr);
        KUNIT_EXPECT_GT(test, real_size, size);

        OPTIMIZER_HIDE_VAR(ptr);

        /* These accesses shouldn't trigger a KASAN report. */
        ptr[0] = 'x';
        ptr[size - 1] = 'x';

        /* These must trigger a KASAN report. */
        if (IS_ENABLED(CONFIG_KASAN_GENERIC))
                KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr)[size + 5]);
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr)[real_size - 1]);

        kfree(ptr);
}

/*
 * Check that a use-after-free is detected by ksize() and via normal accesses
 * after it.
 */
static void ksize_uaf(struct kunit *test)
{
        char *ptr;
        int size = 128 - KASAN_GRANULE_SIZE;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
        kfree(ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr)[0]);
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr)[size]);
}

/*
 * The two tests below check that Generic KASAN prints auxiliary stack traces
 * for RCU callbacks and workqueues. The reports need to be inspected manually.
 *
 * These tests are still enabled for other KASAN modes to make sure that all
 * modes report bad accesses in tested scenarios.
 */

static struct kasan_rcu_info {
        int i;
        struct rcu_head rcu;
} *global_rcu_ptr;

static void rcu_uaf_reclaim(struct rcu_head *rp)
{
        struct kasan_rcu_info *fp =
                container_of(rp, struct kasan_rcu_info, rcu);

        kfree(fp);
        ((volatile struct kasan_rcu_info *)fp)->i;
}

static void rcu_uaf(struct kunit *test)
{
        struct kasan_rcu_info *ptr;

        ptr = kmalloc_obj(struct kasan_rcu_info);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        global_rcu_ptr = rcu_dereference_protected(
                                (struct kasan_rcu_info __rcu *)ptr, NULL);

        KUNIT_EXPECT_KASAN_FAIL_READ(test,
                        call_rcu(&global_rcu_ptr->rcu, rcu_uaf_reclaim);
                        rcu_barrier());
}

static void workqueue_uaf_work(struct work_struct *work)
{
        kfree(work);
}

static void workqueue_uaf(struct kunit *test)
{
        struct workqueue_struct *workqueue;
        struct work_struct *work;

        workqueue = create_workqueue("kasan_workqueue_test");
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, workqueue);

        work = kmalloc_obj(struct work_struct);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, work);

        INIT_WORK(work, workqueue_uaf_work);
        queue_work(workqueue, work);
        destroy_workqueue(workqueue);

        KUNIT_EXPECT_KASAN_FAIL_READ(test,
                        ((volatile struct work_struct *)work)->data);
}

static void kfree_via_page(struct kunit *test)
{
        char *ptr;
        size_t size = 8;
        struct page *page;
        unsigned long offset;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        page = virt_to_page(ptr);
        offset = offset_in_page(ptr);
        kfree(page_address(page) + offset);
}

static void kfree_via_phys(struct kunit *test)
{
        char *ptr;
        size_t size = 8;
        phys_addr_t phys;

        ptr = kmalloc(size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        phys = virt_to_phys(ptr);
        kfree(phys_to_virt(phys));
}

static void kmem_cache_oob(struct kunit *test)
{
        char *p;
        size_t size = 200;
        struct kmem_cache *cache;

        cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);

        p = kmem_cache_alloc(cache, GFP_KERNEL);
        if (!p) {
                kunit_err(test, "Allocation failed: %s\n", __func__);
                kmem_cache_destroy(cache);
                return;
        }

        KUNIT_EXPECT_KASAN_FAIL_READ(test, *p = p[size + OOB_TAG_OFF]);

        kmem_cache_free(cache, p);
        kmem_cache_destroy(cache);
}

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);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);

        p = kmem_cache_alloc(cache, GFP_KERNEL);
        if (!p) {
                kunit_err(test, "Allocation failed: %s\n", __func__);
                kmem_cache_destroy(cache);
                return;
        }

        kmem_cache_free(cache, p);
        KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p));
        kmem_cache_destroy(cache);
}

static void kmem_cache_invalid_free(struct kunit *test)
{
        char *p;
        size_t size = 200;
        struct kmem_cache *cache;

        cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
                                  NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);

        p = kmem_cache_alloc(cache, GFP_KERNEL);
        if (!p) {
                kunit_err(test, "Allocation failed: %s\n", __func__);
                kmem_cache_destroy(cache);
                return;
        }

        /* Trigger invalid free, the object doesn't get freed. */
        KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_free(cache, p + 1));

        /*
         * Properly free the object to prevent the "Objects remaining in
         * test_cache on __kmem_cache_shutdown" BUG failure.
         */
        kmem_cache_free(cache, p);

        kmem_cache_destroy(cache);
}

static void kmem_cache_rcu_uaf(struct kunit *test)
{
        char *p;
        size_t size = 200;
        struct kmem_cache *cache;

        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB_RCU_DEBUG);

        cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
                                  NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);

        p = kmem_cache_alloc(cache, GFP_KERNEL);
        if (!p) {
                kunit_err(test, "Allocation failed: %s\n", __func__);
                kmem_cache_destroy(cache);
                return;
        }
        *p = 1;

        rcu_read_lock();

        /* Free the object - this will internally schedule an RCU callback. */
        kmem_cache_free(cache, p);

        /*
         * We should still be allowed to access the object at this point because
         * the cache is SLAB_TYPESAFE_BY_RCU and we've been in an RCU read-side
         * critical section since before the kmem_cache_free().
         */
        READ_ONCE(*p);

        rcu_read_unlock();

        /*
         * Wait for the RCU callback to execute; after this, the object should
         * have actually been freed from KASAN's perspective.
         */
        rcu_barrier();

        KUNIT_EXPECT_KASAN_FAIL_READ(test, READ_ONCE(*p));

        kmem_cache_destroy(cache);
}

/*
 * Check that SLAB_TYPESAFE_BY_RCU objects are immediately reused when
 * CONFIG_SLUB_RCU_DEBUG is off, and stay at the same address.
 * Without this, KASAN builds would be unable to trigger bugs caused by
 * SLAB_TYPESAFE_BY_RCU users handling reycled objects improperly.
 */
static void kmem_cache_rcu_reuse(struct kunit *test)
{
        char *p, *p2;
        struct kmem_cache *cache;

        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_SLUB_RCU_DEBUG);

        cache = kmem_cache_create("test_cache", 16, 0, SLAB_TYPESAFE_BY_RCU,
                                  NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);

        migrate_disable();
        p = kmem_cache_alloc(cache, GFP_KERNEL);
        if (!p) {
                kunit_err(test, "Allocation failed: %s\n", __func__);
                goto out;
        }

        kmem_cache_free(cache, p);
        p2 = kmem_cache_alloc(cache, GFP_KERNEL);
        if (!p2) {
                kunit_err(test, "Allocation failed: %s\n", __func__);
                goto out;
        }
        KUNIT_EXPECT_PTR_EQ(test, p, p2);

        kmem_cache_free(cache, p2);

out:
        migrate_enable();
        kmem_cache_destroy(cache);
}

static void kmem_cache_double_destroy(struct kunit *test)
{
        struct kmem_cache *cache;

        cache = kmem_cache_create("test_cache", 200, 0, SLAB_NO_MERGE, NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);
        kmem_cache_destroy(cache);
        KUNIT_EXPECT_KASAN_FAIL(test, kmem_cache_destroy(cache));
}

static void kmem_cache_accounted(struct kunit *test)
{
        int i;
        char *p;
        size_t size = 200;
        struct kmem_cache *cache;

        cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);

        /*
         * Several allocations with a delay to allow for lazy per memcg kmem
         * cache creation.
         */
        for (i = 0; i < 5; i++) {
                p = kmem_cache_alloc(cache, GFP_KERNEL);
                if (!p)
                        goto free_cache;

                kmem_cache_free(cache, p);
                msleep(100);
        }

free_cache:
        kmem_cache_destroy(cache);
}

static void kmem_cache_bulk(struct kunit *test)
{
        struct kmem_cache *cache;
        size_t size = 200;
        char *p[10];
        bool ret;
        int i;

        cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);

        ret = kmem_cache_alloc_bulk(cache, GFP_KERNEL, ARRAY_SIZE(p), (void **)&p);
        if (!ret) {
                kunit_err(test, "Allocation failed: %s\n", __func__);
                kmem_cache_destroy(cache);
                return;
        }

        for (i = 0; i < ARRAY_SIZE(p); i++)
                p[i][0] = p[i][size - 1] = 42;

        kmem_cache_free_bulk(cache, ARRAY_SIZE(p), (void **)&p);
        kmem_cache_destroy(cache);
}

static void *mempool_prepare_kmalloc(struct kunit *test, mempool_t *pool, size_t size)
{
        int pool_size = 4;
        int ret;
        void *elem;

        memset(pool, 0, sizeof(*pool));
        ret = mempool_init_kmalloc_pool(pool, pool_size, size);
        KUNIT_ASSERT_EQ(test, ret, 0);

        /*
         * Allocate one element to prevent mempool from freeing elements to the
         * underlying allocator and instead make it add them to the element
         * list when the tests trigger double-free and invalid-free bugs.
         * This allows testing KASAN annotations in add_element().
         */
        elem = mempool_alloc_preallocated(pool);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);

        return elem;
}

static struct kmem_cache *mempool_prepare_slab(struct kunit *test, mempool_t *pool, size_t size)
{
        struct kmem_cache *cache;
        int pool_size = 4;
        int ret;

        cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cache);

        memset(pool, 0, sizeof(*pool));
        ret = mempool_init_slab_pool(pool, pool_size, cache);
        KUNIT_ASSERT_EQ(test, ret, 0);

        /*
         * Do not allocate one preallocated element, as we skip the double-free
         * and invalid-free tests for slab mempool for simplicity.
         */

        return cache;
}

static void *mempool_prepare_page(struct kunit *test, mempool_t *pool, int order)
{
        int pool_size = 4;
        int ret;
        void *elem;

        memset(pool, 0, sizeof(*pool));
        ret = mempool_init_page_pool(pool, pool_size, order);
        KUNIT_ASSERT_EQ(test, ret, 0);

        elem = mempool_alloc_preallocated(pool);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);

        return elem;
}

static void mempool_oob_right_helper(struct kunit *test, mempool_t *pool, size_t size)
{
        char *elem;

        elem = mempool_alloc_preallocated(pool);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);

        OPTIMIZER_HIDE_VAR(elem);

        if (IS_ENABLED(CONFIG_KASAN_GENERIC))
                KUNIT_EXPECT_KASAN_FAIL(test,
                        ((volatile char *)&elem[size])[0]);
        else
                KUNIT_EXPECT_KASAN_FAIL_READ(test,
                        ((volatile char *)&elem[round_up(size, KASAN_GRANULE_SIZE)])[0]);

        mempool_free(elem, pool);
}

static void mempool_kmalloc_oob_right(struct kunit *test)
{
        mempool_t pool;
        size_t size = 128 - KASAN_GRANULE_SIZE - 5;
        void *extra_elem;

        extra_elem = mempool_prepare_kmalloc(test, &pool, size);

        mempool_oob_right_helper(test, &pool, size);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_kmalloc_large_oob_right(struct kunit *test)
{
        mempool_t pool;
        size_t size = KMALLOC_MAX_CACHE_SIZE + 1;
        void *extra_elem;

        extra_elem = mempool_prepare_kmalloc(test, &pool, size);

        mempool_oob_right_helper(test, &pool, size);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_slab_oob_right(struct kunit *test)
{
        mempool_t pool;
        size_t size = 123;
        struct kmem_cache *cache;

        cache = mempool_prepare_slab(test, &pool, size);

        mempool_oob_right_helper(test, &pool, size);

        mempool_exit(&pool);
        kmem_cache_destroy(cache);
}

/*
 * Skip the out-of-bounds test for page mempool. With Generic KASAN, page
 * allocations have no redzones, and thus the out-of-bounds detection is not
 * guaranteed; see https://bugzilla.kernel.org/show_bug.cgi?id=210503. With
 * the tag-based KASAN modes, the neighboring allocation might have the same
 * tag; see https://bugzilla.kernel.org/show_bug.cgi?id=203505.
 */

static void mempool_uaf_helper(struct kunit *test, mempool_t *pool, bool page)
{
        char *elem, *ptr;

        elem = mempool_alloc_preallocated(pool);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);

        mempool_free(elem, pool);

        ptr = page ? page_address((struct page *)elem) : elem;
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)ptr)[0]);
}

static void mempool_kmalloc_uaf(struct kunit *test)
{
        mempool_t pool;
        size_t size = 128;
        void *extra_elem;

        extra_elem = mempool_prepare_kmalloc(test, &pool, size);

        mempool_uaf_helper(test, &pool, false);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_kmalloc_large_uaf(struct kunit *test)
{
        mempool_t pool;
        size_t size = KMALLOC_MAX_CACHE_SIZE + 1;
        void *extra_elem;

        extra_elem = mempool_prepare_kmalloc(test, &pool, size);

        mempool_uaf_helper(test, &pool, false);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_slab_uaf(struct kunit *test)
{
        mempool_t pool;
        size_t size = 123;
        struct kmem_cache *cache;

        cache = mempool_prepare_slab(test, &pool, size);

        mempool_uaf_helper(test, &pool, false);

        mempool_exit(&pool);
        kmem_cache_destroy(cache);
}

static void mempool_page_alloc_uaf(struct kunit *test)
{
        mempool_t pool;
        int order = 2;
        void *extra_elem;

        extra_elem = mempool_prepare_page(test, &pool, order);

        mempool_uaf_helper(test, &pool, true);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_double_free_helper(struct kunit *test, mempool_t *pool)
{
        char *elem;

        elem = mempool_alloc_preallocated(pool);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);

        mempool_free(elem, pool);

        KUNIT_EXPECT_KASAN_FAIL(test, mempool_free(elem, pool));
}

static void mempool_kmalloc_double_free(struct kunit *test)
{
        mempool_t pool;
        size_t size = 128;
        char *extra_elem;

        extra_elem = mempool_prepare_kmalloc(test, &pool, size);

        mempool_double_free_helper(test, &pool);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_kmalloc_large_double_free(struct kunit *test)
{
        mempool_t pool;
        size_t size = KMALLOC_MAX_CACHE_SIZE + 1;
        char *extra_elem;

        extra_elem = mempool_prepare_kmalloc(test, &pool, size);

        mempool_double_free_helper(test, &pool);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_page_alloc_double_free(struct kunit *test)
{
        mempool_t pool;
        int order = 2;
        char *extra_elem;

        extra_elem = mempool_prepare_page(test, &pool, order);

        mempool_double_free_helper(test, &pool);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_kmalloc_invalid_free_helper(struct kunit *test, mempool_t *pool)
{
        char *elem;

        elem = mempool_alloc_preallocated(pool);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, elem);

        KUNIT_EXPECT_KASAN_FAIL(test, mempool_free(elem + 1, pool));

        mempool_free(elem, pool);
}

static void mempool_kmalloc_invalid_free(struct kunit *test)
{
        mempool_t pool;
        size_t size = 128;
        char *extra_elem;

        extra_elem = mempool_prepare_kmalloc(test, &pool, size);

        mempool_kmalloc_invalid_free_helper(test, &pool);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

static void mempool_kmalloc_large_invalid_free(struct kunit *test)
{
        mempool_t pool;
        size_t size = KMALLOC_MAX_CACHE_SIZE + 1;
        char *extra_elem;

        extra_elem = mempool_prepare_kmalloc(test, &pool, size);

        mempool_kmalloc_invalid_free_helper(test, &pool);

        mempool_free(extra_elem, &pool);
        mempool_exit(&pool);
}

/*
 * Skip the invalid-free test for page mempool. The invalid-free detection only
 * works for compound pages and mempool preallocates all page elements without
 * the __GFP_COMP flag.
 */

static char global_array[10];

static void kasan_global_oob_right(struct kunit *test)
{
        /*
         * Deliberate out-of-bounds access. To prevent CONFIG_UBSAN_LOCAL_BOUNDS
         * from failing here and panicking the kernel, access the array via a
         * volatile pointer, which will prevent the compiler from being able to
         * determine the array bounds.
         *
         * This access uses a volatile pointer to char (char *volatile) rather
         * than the more conventional pointer to volatile char (volatile char *)
         * because we want to prevent the compiler from making inferences about
         * the pointer itself (i.e. its array bounds), not the data that it
         * refers to.
         */
        char *volatile array = global_array;
        char *p = &array[ARRAY_SIZE(global_array) + 3];

        /* Only generic mode instruments globals. */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);

        KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}

static void kasan_global_oob_left(struct kunit *test)
{
        char *volatile array = global_array;
        char *p = array - 3;

        /*
         * GCC is known to fail this test, skip it.
         * See https://bugzilla.kernel.org/show_bug.cgi?id=215051.
         */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_CC_IS_CLANG);
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
        KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}

static void kasan_stack_oob(struct kunit *test)
{
        char stack_array[10];
        /* See comment in kasan_global_oob_right. */
        char *volatile array = stack_array;
        char *p = &array[ARRAY_SIZE(stack_array) + OOB_TAG_OFF];

        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);

        KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}

static void kasan_alloca_oob_left(struct kunit *test)
{
        volatile int i = 10;
        char alloca_array[i];
        /* See comment in kasan_global_oob_right. */
        char *volatile array = alloca_array;
        char *p = array - 1;

        /* Only generic mode instruments dynamic allocas. */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);

        KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}

static void kasan_alloca_oob_right(struct kunit *test)
{
        volatile int i = 10;
        char alloca_array[i];
        /* See comment in kasan_global_oob_right. */
        char *volatile array = alloca_array;
        char *p = array + i;

        /* Only generic mode instruments dynamic allocas. */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_STACK);

        KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)p);
}

static void kasan_memchr(struct kunit *test)
{
        char *ptr;
        size_t size = 24;

        /*
         * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
         * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
         */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);

        if (OOB_TAG_OFF)
                size = round_up(size, OOB_TAG_OFF);

        ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(size);
        KUNIT_EXPECT_KASAN_FAIL_READ(test,
                kasan_ptr_result = memchr(ptr, '1', size + 1));

        kfree(ptr);
}

static void kasan_memcmp(struct kunit *test)
{
        char *ptr;
        size_t size = 24;
        int arr[9];

        /*
         * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
         * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
         */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);

        if (OOB_TAG_OFF)
                size = round_up(size, OOB_TAG_OFF);

        ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
        memset(arr, 0, sizeof(arr));

        OPTIMIZER_HIDE_VAR(ptr);
        OPTIMIZER_HIDE_VAR(size);
        KUNIT_EXPECT_KASAN_FAIL_READ(test,
                kasan_int_result = memcmp(ptr, arr, size+1));
        kfree(ptr);
}

static void kasan_strings(struct kunit *test)
{
        char *ptr;
        char *src;
        size_t size = 24;

        /*
         * str* functions are not instrumented with CONFIG_AMD_MEM_ENCRYPT.
         * See https://bugzilla.kernel.org/show_bug.cgi?id=206337 for details.
         */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_AMD_MEM_ENCRYPT);

        ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
        OPTIMIZER_HIDE_VAR(ptr);

        src = kmalloc(KASAN_GRANULE_SIZE, GFP_KERNEL | __GFP_ZERO);
        strscpy(src, "f0cacc1a0000000", KASAN_GRANULE_SIZE);
        OPTIMIZER_HIDE_VAR(src);

        /*
         * Make sure that strscpy() does not trigger KASAN if it overreads into
         * poisoned memory.
         *
         * The expected size does not include the terminator '\0'
         * so it is (KASAN_GRANULE_SIZE - 2) ==
         * KASAN_GRANULE_SIZE - ("initial removed character" + "\0").
         */
        KUNIT_EXPECT_EQ(test, KASAN_GRANULE_SIZE - 2,
                        strscpy(ptr, src + 1, KASAN_GRANULE_SIZE));

        /* strscpy should fail if the first byte is unreadable. */
        KUNIT_EXPECT_KASAN_FAIL_READ(test, strscpy(ptr, src + KASAN_GRANULE_SIZE,
                                              KASAN_GRANULE_SIZE));

        kfree(src);
        kfree(ptr);

        /*
         * Try to cause only 1 invalid access (less spam in dmesg).
         * For that we need ptr to point to zeroed byte.
         * Skip metadata that could be stored in freed object so ptr
         * will likely point to zeroed byte.
         */
        ptr += 16;
        KUNIT_EXPECT_KASAN_FAIL_READ(test, kasan_ptr_result = strchr(ptr, '1'));

        KUNIT_EXPECT_KASAN_FAIL_READ(test, kasan_ptr_result = strrchr(ptr, '1'));

        KUNIT_EXPECT_KASAN_FAIL_READ(test, kasan_int_result = strcmp(ptr, "2"));

        KUNIT_EXPECT_KASAN_FAIL_READ(test, kasan_int_result = strncmp(ptr, "2", 1));

        KUNIT_EXPECT_KASAN_FAIL_READ(test, kasan_int_result = strlen(ptr));

        KUNIT_EXPECT_KASAN_FAIL_READ(test, kasan_int_result = strnlen(ptr, 1));
}

static void kasan_bitops_modify(struct kunit *test, int nr, void *addr)
{
        KUNIT_EXPECT_KASAN_FAIL(test, set_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, __set_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, clear_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, clear_bit_unlock(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, __clear_bit_unlock(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, change_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, __change_bit(nr, addr));
}

static void kasan_bitops_test_and_modify(struct kunit *test, int nr, void *addr)
{
        KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, __test_and_set_bit(nr, addr));
        /*
         * When KASAN is running in write-only mode,
         * a fault won't occur when the bit is set.
         * Therefore, skip the test_and_set_bit_lock test in write-only mode.
         */
        if (!kasan_write_only_enabled())
                KUNIT_EXPECT_KASAN_FAIL(test, test_and_set_bit_lock(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, test_and_clear_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, __test_and_clear_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, test_and_change_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL(test, __test_and_change_bit(nr, addr));
        KUNIT_EXPECT_KASAN_FAIL_READ(test, kasan_int_result = test_bit(nr, addr));
        if (nr < 7)
                KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result =
                                xor_unlock_is_negative_byte(1 << nr, addr));
}

static void kasan_bitops_generic(struct kunit *test)
{
        long *bits;

        /* This test is specifically crafted for the generic mode. */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);

        /*
         * Allocate 1 more byte, which causes kzalloc to round up to 16 bytes;
         * this way we do not actually corrupt other memory.
         */
        bits = kzalloc(sizeof(*bits) + 1, GFP_KERNEL);
        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.
         */
        kasan_bitops_modify(test, BITS_PER_LONG, bits);

        /*
         * Below calls try to access bit beyond allocated memory.
         */
        kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, bits);

        kfree(bits);
}

static void kasan_bitops_tags(struct kunit *test)
{
        long *bits;

        /* This test is specifically crafted for tag-based modes. */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);

        /* kmalloc-64 cache will be used and the last 16 bytes will be the redzone. */
        bits = kzalloc(48, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, bits);

        /* Do the accesses past the 48 allocated bytes, but within the redone. */
        kasan_bitops_modify(test, BITS_PER_LONG, (void *)bits + 48);
        kasan_bitops_test_and_modify(test, BITS_PER_LONG + BITS_PER_BYTE, (void *)bits + 48);

        kfree(bits);
}

static void vmalloc_helpers_tags(struct kunit *test)
{
        void *ptr;

        /* This test is intended for tag-based modes. */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);

        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);

        if (!kasan_vmalloc_enabled())
                kunit_skip(test, "Test requires kasan.vmalloc=on");

        ptr = vmalloc(PAGE_SIZE);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        /* Check that the returned pointer is tagged. */
        KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
        KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);

        /* Make sure exported vmalloc helpers handle tagged pointers. */
        KUNIT_ASSERT_TRUE(test, is_vmalloc_addr(ptr));
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, vmalloc_to_page(ptr));

#if !IS_MODULE(CONFIG_KASAN_KUNIT_TEST)
        {
                int rv;

                /* Make sure vmalloc'ed memory permissions can be changed. */
                rv = set_memory_ro((unsigned long)ptr, 1);
                KUNIT_ASSERT_GE(test, rv, 0);
                rv = set_memory_rw((unsigned long)ptr, 1);
                KUNIT_ASSERT_GE(test, rv, 0);
        }
#endif

        vfree(ptr);
}

static void vmalloc_oob_helper(struct kunit *test, char *v_ptr, size_t size)
{
        /*
         * We have to be careful not to hit the guard page in vmalloc tests.
         * The MMU will catch that and crash us.
         */

        /* Make sure in-bounds accesses are valid. */
        v_ptr[0] = 0;
        v_ptr[size - 1] = 0;

        /*
         * An unaligned access past the requested vmalloc size.
         * Only generic KASAN can precisely detect these.
         */
        if (IS_ENABLED(CONFIG_KASAN_GENERIC))
                KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size]);

        /* An aligned access into the first out-of-bounds granule. */
        size = round_up(size, KASAN_GRANULE_SIZE);
        KUNIT_EXPECT_KASAN_FAIL_READ(test, ((volatile char *)v_ptr)[size]);
}

static void vmalloc_oob(struct kunit *test)
{
        char *v_ptr, *p_ptr;
        struct page *page;
        size_t size = PAGE_SIZE / 2 - KASAN_GRANULE_SIZE - 5;

        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);

        if (!kasan_vmalloc_enabled())
                kunit_skip(test, "Test requires kasan.vmalloc=on");

        v_ptr = vmalloc(size);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);

        OPTIMIZER_HIDE_VAR(v_ptr);

        vmalloc_oob_helper(test, v_ptr, size);

        size -= KASAN_GRANULE_SIZE + 1;
        v_ptr = vrealloc(v_ptr, size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);

        OPTIMIZER_HIDE_VAR(v_ptr);

        vmalloc_oob_helper(test, v_ptr, size);

        size += 2 * KASAN_GRANULE_SIZE + 2;
        v_ptr = vrealloc(v_ptr, size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);

        vmalloc_oob_helper(test, v_ptr, size);

        /* Check that in-bounds accesses to the physical page are valid. */
        page = vmalloc_to_page(v_ptr);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
        p_ptr = page_address(page);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);
        p_ptr[0] = 0;

        vfree(v_ptr);

        /*
         * We can't check for use-after-unmap bugs in this nor in the following
         * vmalloc tests, as the page might be fully unmapped and accessing it
         * will crash the kernel.
         */
}

static void vmap_tags(struct kunit *test)
{
        char *p_ptr, *v_ptr;
        struct page *p_page, *v_page;

        /*
         * This test is specifically crafted for the software tag-based mode,
         * the only tag-based mode that poisons vmap mappings.
         */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);

        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);

        if (!kasan_vmalloc_enabled())
                kunit_skip(test, "Test requires kasan.vmalloc=on");

        p_page = alloc_pages(GFP_KERNEL, 1);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_page);
        p_ptr = page_address(p_page);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);

        v_ptr = vmap(&p_page, 1, VM_MAP, PAGE_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);

        /*
         * We can't check for out-of-bounds bugs in this nor in the following
         * vmalloc tests, as allocations have page granularity and accessing
         * the guard page will crash the kernel.
         */

        KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
        KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL);

        /* Make sure that in-bounds accesses through both pointers work. */
        *p_ptr = 0;
        *v_ptr = 0;

        /* Make sure vmalloc_to_page() correctly recovers the page pointer. */
        v_page = vmalloc_to_page(v_ptr);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_page);
        KUNIT_EXPECT_PTR_EQ(test, p_page, v_page);

        vunmap(v_ptr);
        free_pages((unsigned long)p_ptr, 1);
}

static void vm_map_ram_tags(struct kunit *test)
{
        char *p_ptr, *v_ptr;
        struct page *page;

        /*
         * This test is specifically crafted for the software tag-based mode,
         * the only tag-based mode that poisons vm_map_ram mappings.
         */
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);

        page = alloc_pages(GFP_KERNEL, 1);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, page);
        p_ptr = page_address(page);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, p_ptr);

        v_ptr = vm_map_ram(&page, 1, -1);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, v_ptr);

        KUNIT_EXPECT_GE(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_MIN);
        KUNIT_EXPECT_LT(test, (u8)get_tag(v_ptr), (u8)KASAN_TAG_KERNEL);

        /* Make sure that in-bounds accesses through both pointers work. */
        *p_ptr = 0;
        *v_ptr = 0;

        vm_unmap_ram(v_ptr, 1);
        free_pages((unsigned long)p_ptr, 1);
}

/*
 * Check that the assigned pointer tag falls within the [KASAN_TAG_MIN,
 * KASAN_TAG_KERNEL) range (note: excluding the match-all tag) for tag-based
 * modes.
 */
static void match_all_not_assigned(struct kunit *test)
{
        char *ptr;
        struct page *pages;
        int i, size, order;

        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);

        for (i = 0; i < 256; i++) {
                size = get_random_u32_inclusive(1, 1024);
                ptr = kmalloc(size, GFP_KERNEL);
                KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
                KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
                KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
                kfree(ptr);
        }

        for (i = 0; i < 256; i++) {
                order = get_random_u32_inclusive(1, 4);
                pages = alloc_pages(GFP_KERNEL, order);
                ptr = page_address(pages);
                KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
                KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
                KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
                free_pages((unsigned long)ptr, order);
        }

        if (!kasan_vmalloc_enabled())
                return;

        for (i = 0; i < 256; i++) {
                size = get_random_u32_inclusive(1, 1024);
                ptr = vmalloc(size);
                KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
                KUNIT_EXPECT_GE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_MIN);
                KUNIT_EXPECT_LT(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);
                vfree(ptr);
        }
}

/* Check that 0xff works as a match-all pointer tag for tag-based modes. */
static void match_all_ptr_tag(struct kunit *test)
{
        char *ptr;
        u8 tag;

        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);

        ptr = kmalloc(128, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);

        /* Backup the assigned tag. */
        tag = get_tag(ptr);
        KUNIT_EXPECT_NE(test, tag, (u8)KASAN_TAG_KERNEL);

        /* Reset the tag to 0xff.*/
        ptr = set_tag(ptr, KASAN_TAG_KERNEL);

        /* This access shouldn't trigger a KASAN report. */
        *ptr = 0;

        /* Recover the pointer tag and free. */
        ptr = set_tag(ptr, tag);
        kfree(ptr);
}

/* Check that there are no match-all memory tags for tag-based modes. */
static void match_all_mem_tag(struct kunit *test)
{
        char *ptr;
        int tag;

        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_GENERIC);

        ptr = kmalloc(128, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
        KUNIT_EXPECT_NE(test, (u8)get_tag(ptr), (u8)KASAN_TAG_KERNEL);

        /* For each possible tag value not matching the pointer tag. */
        for (tag = KASAN_TAG_MIN; tag <= KASAN_TAG_KERNEL; tag++) {
                /*
                 * For Software Tag-Based KASAN, skip the majority of tag
                 * values to avoid the test printing too many reports.
                 */
                if (IS_ENABLED(CONFIG_KASAN_SW_TAGS) &&
                    tag >= KASAN_TAG_MIN + 8 && tag <= KASAN_TAG_KERNEL - 8)
                        continue;

                if (tag == get_tag(ptr))
                        continue;

                /* Mark the first memory granule with the chosen memory tag. */
                kasan_poison(ptr, KASAN_GRANULE_SIZE, (u8)tag, false);

                /* This access must cause a KASAN report. */
                KUNIT_EXPECT_KASAN_FAIL(test, *ptr = 0);
        }

        /* Recover the memory tag and free. */
        kasan_poison(ptr, KASAN_GRANULE_SIZE, get_tag(ptr), false);
        kfree(ptr);
}

/*
 * Check that Rust performing a use-after-free using `unsafe` is detected.
 * This is a smoke test to make sure that Rust is being sanitized properly.
 */
static void rust_uaf(struct kunit *test)
{
        KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_RUST);
        KUNIT_EXPECT_KASAN_FAIL(test, kasan_test_rust_uaf());
}

/*
 * copy_to_kernel_nofault() is an internal helper available when
 * kasan_test is built-in, so it must not be visible to loadable modules.
 */
#ifndef MODULE
static void copy_to_kernel_nofault_oob(struct kunit *test)
{
        char *ptr;
        char buf[128];
        size_t size = sizeof(buf);

        /*
         * This test currently fails with the HW_TAGS mode. The reason is
         * unknown and needs to be investigated.
         */
        KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);

        ptr = kmalloc(size - KASAN_GRANULE_SIZE, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
        OPTIMIZER_HIDE_VAR(ptr);

        /*
         * We test copy_to_kernel_nofault() to detect corrupted memory that is
         * being written into the kernel. In contrast,
         * copy_from_kernel_nofault() is primarily used in kernel helper
         * functions where the source address might be random or uninitialized.
         * Applying KASAN instrumentation to copy_from_kernel_nofault() could
         * lead to false positives.  By focusing KASAN checks only on
         * copy_to_kernel_nofault(), we ensure that only valid memory is
         * written to the kernel, minimizing the risk of kernel corruption
         * while avoiding false positives in the reverse case.
         */
        KUNIT_EXPECT_KASAN_FAIL(test,
                copy_to_kernel_nofault(&buf[0], ptr, size));
        KUNIT_EXPECT_KASAN_FAIL(test,
                copy_to_kernel_nofault(ptr, &buf[0], size));

        kfree(ptr);
}
#endif /* !MODULE */

static void copy_user_test_oob(struct kunit *test)
{
        char *kmem;
        char __user *usermem;
        unsigned long useraddr;
        size_t size = 128 - KASAN_GRANULE_SIZE;
        int __maybe_unused unused;

        kmem = kunit_kmalloc(test, size, GFP_KERNEL);
        KUNIT_ASSERT_NOT_ERR_OR_NULL(test, kmem);

        useraddr = kunit_vm_mmap(test, NULL, 0, PAGE_SIZE,
                                        PROT_READ | PROT_WRITE | PROT_EXEC,
                                        MAP_ANONYMOUS | MAP_PRIVATE, 0);
        KUNIT_ASSERT_NE_MSG(test, useraddr, 0,
                "Could not create userspace mm");
        KUNIT_ASSERT_LT_MSG(test, useraddr, (unsigned long)TASK_SIZE,
                "Failed to allocate user memory");

        OPTIMIZER_HIDE_VAR(size);
        usermem = (char __user *)useraddr;

        KUNIT_EXPECT_KASAN_FAIL(test,
                unused = copy_from_user(kmem, usermem, size + 1));
        KUNIT_EXPECT_KASAN_FAIL_READ(test,
                unused = copy_to_user(usermem, kmem, size + 1));
        KUNIT_EXPECT_KASAN_FAIL(test,
                unused = __copy_from_user(kmem, usermem, size + 1));
        KUNIT_EXPECT_KASAN_FAIL_READ(test,
                unused = __copy_to_user(usermem, kmem, size + 1));
        KUNIT_EXPECT_KASAN_FAIL(test,
                unused = __copy_from_user_inatomic(kmem, usermem, size + 1));
        KUNIT_EXPECT_KASAN_FAIL_READ(test,
                unused = __copy_to_user_inatomic(usermem, kmem, size + 1));

        /*
        * Prepare a long string in usermem to avoid the strncpy_from_user test
        * bailing out on '\0' before it reaches out-of-bounds.
        */
        memset(kmem, 'a', size);
        KUNIT_EXPECT_EQ(test, copy_to_user(usermem, kmem, size), 0);

        KUNIT_EXPECT_KASAN_FAIL(test,
                unused = strncpy_from_user(kmem, usermem, size + 1));
}

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_track_caller_oob_right),
        KUNIT_CASE(kmalloc_big_oob_right),
        KUNIT_CASE(kmalloc_large_oob_right),
        KUNIT_CASE(kmalloc_large_uaf),
        KUNIT_CASE(kmalloc_large_invalid_free),
        KUNIT_CASE(page_alloc_oob_right),
        KUNIT_CASE(page_alloc_uaf),
        KUNIT_CASE(krealloc_more_oob),
        KUNIT_CASE(krealloc_less_oob),
        KUNIT_CASE(krealloc_large_more_oob),
        KUNIT_CASE(krealloc_large_less_oob),
        KUNIT_CASE(krealloc_uaf),
        KUNIT_CASE(kmalloc_oob_16),
        KUNIT_CASE(kmalloc_uaf_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_negative_size),
        KUNIT_CASE(kmalloc_memmove_invalid_size),
        KUNIT_CASE(kmalloc_uaf),
        KUNIT_CASE(kmalloc_uaf_memset),
        KUNIT_CASE(kmalloc_uaf2),
        KUNIT_CASE(kmalloc_uaf3),
        KUNIT_CASE(kmalloc_double_kzfree),
        KUNIT_CASE(ksize_unpoisons_memory),
        KUNIT_CASE(ksize_uaf),
        KUNIT_CASE(rcu_uaf),
        KUNIT_CASE(workqueue_uaf),
        KUNIT_CASE(kfree_via_page),
        KUNIT_CASE(kfree_via_phys),
        KUNIT_CASE(kmem_cache_oob),
        KUNIT_CASE(kmem_cache_double_free),
        KUNIT_CASE(kmem_cache_invalid_free),
        KUNIT_CASE(kmem_cache_rcu_uaf),
        KUNIT_CASE(kmem_cache_rcu_reuse),
        KUNIT_CASE(kmem_cache_double_destroy),
        KUNIT_CASE(kmem_cache_accounted),
        KUNIT_CASE(kmem_cache_bulk),
        KUNIT_CASE(mempool_kmalloc_oob_right),
        KUNIT_CASE(mempool_kmalloc_large_oob_right),
        KUNIT_CASE(mempool_slab_oob_right),
        KUNIT_CASE(mempool_kmalloc_uaf),
        KUNIT_CASE(mempool_kmalloc_large_uaf),
        KUNIT_CASE(mempool_slab_uaf),
        KUNIT_CASE(mempool_page_alloc_uaf),
        KUNIT_CASE(mempool_kmalloc_double_free),
        KUNIT_CASE(mempool_kmalloc_large_double_free),
        KUNIT_CASE(mempool_page_alloc_double_free),
        KUNIT_CASE(mempool_kmalloc_invalid_free),
        KUNIT_CASE(mempool_kmalloc_large_invalid_free),
        KUNIT_CASE(kasan_global_oob_right),
        KUNIT_CASE(kasan_global_oob_left),
        KUNIT_CASE(kasan_stack_oob),
        KUNIT_CASE(kasan_alloca_oob_left),
        KUNIT_CASE(kasan_alloca_oob_right),
        KUNIT_CASE(kasan_memchr),
        KUNIT_CASE(kasan_memcmp),
        KUNIT_CASE(kasan_strings),
        KUNIT_CASE(kasan_bitops_generic),
        KUNIT_CASE(kasan_bitops_tags),
        KUNIT_CASE_SLOW(kasan_atomics),
        KUNIT_CASE(vmalloc_helpers_tags),
        KUNIT_CASE(vmalloc_oob),
        KUNIT_CASE(vmap_tags),
        KUNIT_CASE(vm_map_ram_tags),
        KUNIT_CASE(match_all_not_assigned),
        KUNIT_CASE(match_all_ptr_tag),
        KUNIT_CASE(match_all_mem_tag),
#ifndef MODULE
        KUNIT_CASE(copy_to_kernel_nofault_oob),
#endif
        KUNIT_CASE(rust_uaf),
        KUNIT_CASE(copy_user_test_oob),
        {}
};

static struct kunit_suite kasan_kunit_test_suite = {
        .name = "kasan",
        .test_cases = kasan_kunit_test_cases,
        .exit = kasan_test_exit,
        .suite_init = kasan_suite_init,
        .suite_exit = kasan_suite_exit,
};

kunit_test_suite(kasan_kunit_test_suite);

MODULE_DESCRIPTION("KUnit tests for checking KASAN bug-detection capabilities");
MODULE_LICENSE("GPL");