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// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
* Author: Andrey Ryabinin <a.ryabinin@samsung.com>
*/
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/kasan.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/module.h>
#include <linux/printk.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/vmalloc.h>
#include <asm/page.h>
#include <kunit/test.h>
#include "../mm/kasan/kasan.h"
#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
/*
* Some tests use these global variables to store return values from function
* calls that could otherwise be eliminated by the compiler as dead code.
*/
void *kasan_ptr_result;
int kasan_int_result;
static struct kunit_resource resource;
static struct kunit_kasan_expectation fail_data;
static bool multishot;
/*
* Temporarily enable multi-shot mode. Otherwise, KASAN would only report the
* first detected bug and panic the kernel if panic_on_warn is enabled. For
* hardware tag-based KASAN also allow tag checking to be reenabled for each
* test, see the comment for KUNIT_EXPECT_KASAN_FAIL().
*/
static int kasan_test_init(struct kunit *test)
{
if (!kasan_enabled()) {
kunit_err(test, "can't run KASAN tests with KASAN disabled");
return -1;
}
multishot = kasan_save_enable_multi_shot();
kasan_set_tagging_report_once(false);
fail_data.report_found = false;
fail_data.report_expected = false;
kunit_add_named_resource(test, NULL, NULL, &resource,
"kasan_data", &fail_data);
return 0;
}
static void kasan_test_exit(struct kunit *test)
{
kasan_set_tagging_report_once(true);
kasan_restore_multi_shot(multishot);
KUNIT_EXPECT_FALSE(test, fail_data.report_found);
}
/**
* KUNIT_EXPECT_KASAN_FAIL() - check that the executed expression produces a
* KASAN report; causes a test failure otherwise. This relies on a KUnit
* resource named "kasan_data". Do not use this name for KUnit resources
* outside of KASAN tests.
*
* For hardware tag-based KASAN in sync mode, when a 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 fail_data
* 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_FAIL checks, fail_data.report_found is kept as
* false. This allows detecting KASAN reports that happen outside of the checks
* by asserting !fail_data.report_found at the start of KUNIT_EXPECT_KASAN_FAIL
* and in kasan_test_exit.
*/
#define KUNIT_EXPECT_KASAN_FAIL(test, expression) do { \
if (IS_ENABLED(CONFIG_KASAN_HW_TAGS) && \
!kasan_async_mode_enabled()) \
migrate_disable(); \
KUNIT_EXPECT_FALSE(test, READ_ONCE(fail_data.report_found)); \
WRITE_ONCE(fail_data.report_expected, true); \
barrier(); \
expression; \
barrier(); \
KUNIT_EXPECT_EQ(test, \
READ_ONCE(fail_data.report_expected), \
READ_ONCE(fail_data.report_found)); \
if (IS_ENABLED(CONFIG_KASAN_HW_TAGS)) { \
if (READ_ONCE(fail_data.report_found)) \
kasan_enable_tagging_sync(); \
migrate_enable(); \
} \
WRITE_ONCE(fail_data.report_found, false); \
WRITE_ONCE(fail_data.report_expected, false); \
} while (0)
#define KASAN_TEST_NEEDS_CONFIG_ON(test, config) do { \
if (!IS_ENABLED(config)) { \
kunit_info((test), "skipping, " #config " required"); \
return; \
} \
} while (0)
#define KASAN_TEST_NEEDS_CONFIG_OFF(test, config) do { \
if (IS_ENABLED(config)) { \
kunit_info((test), "skipping, " #config " enabled"); \
return; \
} \
} while (0)
static void kmalloc_oob_right(struct kunit *test)
{
char *ptr;
size_t size = 123;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 'x');
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);
KUNIT_EXPECT_KASAN_FAIL(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);
KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
kfree(ptr);
}
/*
* These kmalloc_pagealloc_* tests try allocating a memory chunk that doesn't
* fit into a slab cache and therefore is allocated via the page allocator
* fallback. Since this kind of fallback is only implemented for SLUB, these
* tests are limited to that allocator.
*/
static void kmalloc_pagealloc_oob_right(struct kunit *test)
{
char *ptr;
size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 0);
kfree(ptr);
}
static void kmalloc_pagealloc_uaf(struct kunit *test)
{
char *ptr;
size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
kfree(ptr);
KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
}
static void kmalloc_pagealloc_invalid_free(struct kunit *test)
{
char *ptr;
size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, kfree(ptr + 1));
}
static void pagealloc_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(test, ptr[size] = 0);
free_pages((unsigned long)ptr, order);
}
static void pagealloc_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(test, ptr[0] = 0);
}
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.
*/
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
kfree(ptr);
}
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);
/* 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);
/* 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_pagealloc_more_oob(struct kunit *test)
{
/* page_alloc fallback in only implemented for SLUB. */
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
krealloc_more_oob_helper(test, KMALLOC_MAX_CACHE_SIZE + 201,
KMALLOC_MAX_CACHE_SIZE + 235);
}
static void krealloc_pagealloc_less_oob(struct kunit *test)
{
/* page_alloc fallback in only implemented for SLUB. */
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_SLUB);
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_PTR_EQ(test, (void *)ptr2, NULL);
KUNIT_EXPECT_KASAN_FAIL(test, *(volatile char *)ptr1);
}
static void kmalloc_oob_16(struct kunit *test)
{
struct {
u64 words[2];
} *ptr1, *ptr2;
/* This test is specifically crafted for the generic mode. */
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, 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;
ptr1 = kmalloc(sizeof(*ptr1), GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr1);
ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr2);
kfree(ptr2);
KUNIT_EXPECT_KASAN_FAIL(test, *ptr1 = *ptr2);
kfree(ptr1);
}
static void kmalloc_oob_memset_2(struct kunit *test)
{
char *ptr;
size_t size = 8;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 7 + OOB_TAG_OFF, 0, 2));
kfree(ptr);
}
static void kmalloc_oob_memset_4(struct kunit *test)
{
char *ptr;
size_t size = 8;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 5 + OOB_TAG_OFF, 0, 4));
kfree(ptr);
}
static void kmalloc_oob_memset_8(struct kunit *test)
{
char *ptr;
size_t size = 8;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 8));
kfree(ptr);
}
static void kmalloc_oob_memset_16(struct kunit *test)
{
char *ptr;
size_t size = 16;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 16));
kfree(ptr);
}
static void kmalloc_oob_in_memset(struct kunit *test)
{
char *ptr;
size_t size = 666;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size + 5 + OOB_TAG_OFF));
kfree(ptr);
}
static void kmalloc_memmove_invalid_size(struct kunit *test)
{
char *ptr;
size_t size = 64;
volatile size_t invalid_size = -2;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
memset((char *)ptr, 0, 64);
KUNIT_EXPECT_KASAN_FAIL(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(test, *(ptr + 8) = 'x');
}
static void kmalloc_uaf_memset(struct kunit *test)
{
char *ptr;
size_t size = 33;
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(test, ptr1[40] = 'x');
KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
kfree(ptr2);
}
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(test, *p = p[size + OOB_TAG_OFF]);
kmem_cache_free(cache, p);
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 char global_array[10];
static void kasan_global_oob(struct kunit *test)
{
/*
* Deliberate out-of-bounds access. To prevent CONFIG_UBSAN_LOCAL_BOUNDS
* from failing here and panicing 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);
}
/* Check that ksize() makes the whole object accessible. */
static void ksize_unpoisons_memory(struct kunit *test)
{
char *ptr;
size_t size = 123, real_size;
ptr = kmalloc(size, GFP_KERNEL);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
real_size = ksize(ptr);
/* This access shouldn't trigger a KASAN report. */
ptr[size] = 'x';
/* This one must. */
KUNIT_EXPECT_KASAN_FAIL(test, ptr[real_size] = 'y');
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);
KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = *ptr);
KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = *(ptr + size));
}
static void kasan_stack_oob(struct kunit *test)
{
char stack_array[10];
/* See comment in kasan_global_oob. */
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. */
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. */
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 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 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);
KUNIT_EXPECT_KASAN_FAIL(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));
KUNIT_EXPECT_KASAN_FAIL(test,
kasan_int_result = memcmp(ptr, arr, size+1));
kfree(ptr);
}
static void kasan_strings(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);
ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
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(test, kasan_ptr_result = strchr(ptr, '1'));
KUNIT_EXPECT_KASAN_FAIL(test, kasan_ptr_result = strrchr(ptr, '1'));
KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strcmp(ptr, "2"));
KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strncmp(ptr, "2", 1));
KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = strlen(ptr));
KUNIT_EXPECT_KASAN_FAIL(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));
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(test, kasan_int_result = test_bit(nr, addr));
#if defined(clear_bit_unlock_is_negative_byte)
KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result =
clear_bit_unlock_is_negative_byte(nr, addr));
#endif
}
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 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));
}
static void vmalloc_oob(struct kunit *test)
{
void *area;
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_VMALLOC);
/*
* We have to be careful not to hit the guard page.
* The MMU will catch that and crash us.
*/
area = vmalloc(3000);
KUNIT_ASSERT_NOT_ERR_OR_NULL(test, area);
KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)area)[3100]);
vfree(area);
}
/*
* 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_int() % 1024) + 1;
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_int() % 4) + 1;
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);
}
}
/* 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++) {
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);
}
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(pagealloc_oob_right),
KUNIT_CASE(pagealloc_uaf),
KUNIT_CASE(kmalloc_large_oob_right),
KUNIT_CASE(krealloc_more_oob),
KUNIT_CASE(krealloc_less_oob),
KUNIT_CASE(krealloc_pagealloc_more_oob),
KUNIT_CASE(krealloc_pagealloc_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_invalid_size),
KUNIT_CASE(kmalloc_uaf),
KUNIT_CASE(kmalloc_uaf_memset),
KUNIT_CASE(kmalloc_uaf2),
KUNIT_CASE(kfree_via_page),
KUNIT_CASE(kfree_via_phys),
KUNIT_CASE(kmem_cache_oob),
KUNIT_CASE(kmem_cache_accounted),
KUNIT_CASE(kmem_cache_bulk),
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(ksize_uaf),
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_generic),
KUNIT_CASE(kasan_bitops_tags),
KUNIT_CASE(kmalloc_double_kzfree),
KUNIT_CASE(vmalloc_oob),
KUNIT_CASE(match_all_not_assigned),
KUNIT_CASE(match_all_ptr_tag),
KUNIT_CASE(match_all_mem_tag),
{}
};
static struct kunit_suite kasan_kunit_test_suite = {
.name = "kasan",
.init = kasan_test_init,
.test_cases = kasan_kunit_test_cases,
.exit = kasan_test_exit,
};
kunit_test_suite(kasan_kunit_test_suite);
MODULE_LICENSE("GPL");