// SPDX-License-Identifier: GPL-2.0-only
/*
*
* Copyright (c) 2014 Samsung Electronics Co., Ltd.
* Author: Andrey Ryabinin <[email protected]>
*/
#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)
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.
*/
void *kasan_ptr_result;
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_FAIL - check that the executed expression produces a
* KASAN report; causes a KUnit test failure otherwise.
*
* @test: Currently executing KUnit test.
* @expression: Expression that must 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_FAIL 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_FAIL and in kasan_test_exit.
*/
#define KUNIT_EXPECT_KASAN_FAIL(test, expression) 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(); \
expression; \
barrier(); \
if (kasan_async_fault_possible()) \
kasan_force_async_fault(); \
if (!READ_ONCE(test_status.report_found)) { \
KUNIT_FAIL(test, KUNIT_SUBTEST_INDENT "KASAN failure " \
"expected in \"" #expression \
"\", but none occurred"); \
} \
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)
#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(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(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(test, ptr[0] = ptr[size]);
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(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(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(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(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(sizeof(*ptr2), GFP_KERNEL);
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(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);
}
/*
* 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(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, ((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(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(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(test, READ_ONCE(*i_unsafe));
KUNIT_EXPECT_KASAN_FAIL(test, WRITE_ONCE(*i_unsafe, 42));
KUNIT_EXPECT_KASAN_FAIL(test, smp_load_acquire(i_unsafe));
KUNIT_EXPECT_KASAN_FAIL(test, smp_store_release(i_unsafe, 42));
KUNIT_EXPECT_KASAN_FAIL(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));
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));
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(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));
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));
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(sizeof(atomic_long_t), GFP_KERNEL);
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(test, ((volatile char *)ptr)[size + 5]);
KUNIT_EXPECT_KASAN_FAIL(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(test, ((volatile char *)ptr)[0]);
KUNIT_EXPECT_KASAN_FAIL(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(sizeof(struct kasan_rcu_info), GFP_KERNEL);
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(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(sizeof(struct work_struct), GFP_KERNEL);
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(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(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 empty_cache_ctor(void *object) { }
static void kmem_cache_double_destroy(struct kunit *test)
{
struct kmem_cache *cache;
/* Provide a constructor to prevent cache merging. */
cache = kmem_cache_create("test_cache", 200, 0, 0, empty_cache_ctor);
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(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(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(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(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 (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(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);
/*
* 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. */
KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)v_ptr)[size + 5]);
/* 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);
}
static void vmalloc_percpu(struct kunit *test)
{
char __percpu *ptr;
int cpu;
/*
* This test is specifically crafted for the software tag-based mode,
* the only tag-based mode that poisons percpu mappings.
*/
KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
ptr = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
for_each_possible_cpu(cpu) {
char *c_ptr = per_cpu_ptr(ptr, cpu);
KUNIT_EXPECT_GE(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_MIN);
KUNIT_EXPECT_LT(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_KERNEL);
/* Make sure that in-bounds accesses don't crash the kernel. */
*c_ptr = 0;
}
free_percpu(ptr);
}
/*
* 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);
}
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_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_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(kasan_atomics),
KUNIT_CASE(vmalloc_helpers_tags),
KUNIT_CASE(vmalloc_oob),
KUNIT_CASE(vmap_tags),
KUNIT_CASE(vm_map_ram_tags),
KUNIT_CASE(vmalloc_percpu),
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",
.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_LICENSE("GPL");