[linux.git] / lib / test_kasan.c

/*
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
 * Author: Andrey Ryabinin <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

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

#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/kasan.h>

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

static noinline void __init kmalloc_oob_right(void)
{
	char *ptr;
	size_t size = 123;

	pr_info("out-of-bounds to right\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	ptr[size] = 'x';
	kfree(ptr);
}

static noinline void __init kmalloc_oob_left(void)
{
	char *ptr;
	size_t size = 15;

	pr_info("out-of-bounds to left\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	*ptr = *(ptr - 1);
	kfree(ptr);
}

static noinline void __init kmalloc_node_oob_right(void)
{
	char *ptr;
	size_t size = 4096;

	pr_info("kmalloc_node(): out-of-bounds to right\n");
	ptr = kmalloc_node(size, GFP_KERNEL, 0);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	ptr[size] = 0;
	kfree(ptr);
}

#ifdef CONFIG_SLUB
static noinline void __init kmalloc_pagealloc_oob_right(void)
{
	char *ptr;
	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;

	/* Allocate a chunk that does not fit into a SLUB cache to trigger
	 * the page allocator fallback.
	 */
	pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	ptr[size] = 0;
	kfree(ptr);
}

static noinline void __init kmalloc_pagealloc_uaf(void)
{
	char *ptr;
	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;

	pr_info("kmalloc pagealloc allocation: use-after-free\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	kfree(ptr);
	ptr[0] = 0;
}

static noinline void __init kmalloc_pagealloc_invalid_free(void)
{
	char *ptr;
	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;

	pr_info("kmalloc pagealloc allocation: invalid-free\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	kfree(ptr + 1);
}
#endif

static noinline void __init kmalloc_large_oob_right(void)
{
	char *ptr;
	size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
	/* Allocate a chunk that is large enough, but still fits into a slab
	 * and does not trigger the page allocator fallback in SLUB.
	 */
	pr_info("kmalloc large allocation: out-of-bounds to right\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	ptr[size] = 0;
	kfree(ptr);
}

static noinline void __init kmalloc_oob_krealloc_more(void)
{
	char *ptr1, *ptr2;
	size_t size1 = 17;
	size_t size2 = 19;

	pr_info("out-of-bounds after krealloc more\n");
	ptr1 = kmalloc(size1, GFP_KERNEL);
	ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
	if (!ptr1 || !ptr2) {
		pr_err("Allocation failed\n");
		kfree(ptr1);
		return;
	}

	ptr2[size2] = 'x';
	kfree(ptr2);
}

static noinline void __init kmalloc_oob_krealloc_less(void)
{
	char *ptr1, *ptr2;
	size_t size1 = 17;
	size_t size2 = 15;

	pr_info("out-of-bounds after krealloc less\n");
	ptr1 = kmalloc(size1, GFP_KERNEL);
	ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
	if (!ptr1 || !ptr2) {
		pr_err("Allocation failed\n");
		kfree(ptr1);
		return;
	}
	ptr2[size2] = 'x';
	kfree(ptr2);
}

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

	pr_info("kmalloc out-of-bounds for 16-bytes access\n");
	ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
	ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
	if (!ptr1 || !ptr2) {
		pr_err("Allocation failed\n");
		kfree(ptr1);
		kfree(ptr2);
		return;
	}
	*ptr1 = *ptr2;
	kfree(ptr1);
	kfree(ptr2);
}

static noinline void __init kmalloc_oob_memset_2(void)
{
	char *ptr;
	size_t size = 8;

	pr_info("out-of-bounds in memset2\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	memset(ptr+7, 0, 2);
	kfree(ptr);
}

static noinline void __init kmalloc_oob_memset_4(void)
{
	char *ptr;
	size_t size = 8;

	pr_info("out-of-bounds in memset4\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	memset(ptr+5, 0, 4);
	kfree(ptr);
}


static noinline void __init kmalloc_oob_memset_8(void)
{
	char *ptr;
	size_t size = 8;

	pr_info("out-of-bounds in memset8\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	memset(ptr+1, 0, 8);
	kfree(ptr);
}

static noinline void __init kmalloc_oob_memset_16(void)
{
	char *ptr;
	size_t size = 16;

	pr_info("out-of-bounds in memset16\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	memset(ptr+1, 0, 16);
	kfree(ptr);
}

static noinline void __init kmalloc_oob_in_memset(void)
{
	char *ptr;
	size_t size = 666;

	pr_info("out-of-bounds in memset\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	memset(ptr, 0, size+5);
	kfree(ptr);
}

static noinline void __init kmalloc_uaf(void)
{
	char *ptr;
	size_t size = 10;

	pr_info("use-after-free\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

	kfree(ptr);
	*(ptr + 8) = 'x';
}

static noinline void __init kmalloc_uaf_memset(void)
{
	char *ptr;
	size_t size = 33;

	pr_info("use-after-free in memset\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}

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

static noinline void __init kmalloc_uaf2(void)
{
	char *ptr1, *ptr2;
	size_t size = 43;

	pr_info("use-after-free after another kmalloc\n");
	ptr1 = kmalloc(size, GFP_KERNEL);
	if (!ptr1) {
		pr_err("Allocation failed\n");
		return;
	}

	kfree(ptr1);
	ptr2 = kmalloc(size, GFP_KERNEL);
	if (!ptr2) {
		pr_err("Allocation failed\n");
		return;
	}

	ptr1[40] = 'x';
	if (ptr1 == ptr2)
		pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
	kfree(ptr2);
}

static noinline void __init kmem_cache_oob(void)
{
	char *p;
	size_t size = 200;
	struct kmem_cache *cache = kmem_cache_create("test_cache",
						size, 0,
						0, NULL);
	if (!cache) {
		pr_err("Cache allocation failed\n");
		return;
	}
	pr_info("out-of-bounds in kmem_cache_alloc\n");
	p = kmem_cache_alloc(cache, GFP_KERNEL);
	if (!p) {
		pr_err("Allocation failed\n");
		kmem_cache_destroy(cache);
		return;
	}

	*p = p[size];
	kmem_cache_free(cache, p);
	kmem_cache_destroy(cache);
}

static noinline void __init memcg_accounted_kmem_cache(void)
{
	int i;
	char *p;
	size_t size = 200;
	struct kmem_cache *cache;

	cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
	if (!cache) {
		pr_err("Cache allocation failed\n");
		return;
	}

	pr_info("allocate memcg accounted object\n");
	/*
	 * 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 char global_array[10];

static noinline void __init kasan_global_oob(void)
{
	volatile int i = 3;
	char *p = &global_array[ARRAY_SIZE(global_array) + i];

	pr_info("out-of-bounds global variable\n");
	*(volatile char *)p;
}

static noinline void __init kasan_stack_oob(void)
{
	char stack_array[10];
	volatile int i = 0;
	char *p = &stack_array[ARRAY_SIZE(stack_array) + i];

	pr_info("out-of-bounds on stack\n");
	*(volatile char *)p;
}

static noinline void __init ksize_unpoisons_memory(void)
{
	char *ptr;
	size_t size = 123, real_size;

	pr_info("ksize() unpoisons the whole allocated chunk\n");
	ptr = kmalloc(size, GFP_KERNEL);
	if (!ptr) {
		pr_err("Allocation failed\n");
		return;
	}
	real_size = ksize(ptr);
	/* This access doesn't trigger an error. */
	ptr[size] = 'x';
	/* This one does. */
	ptr[real_size] = 'y';
	kfree(ptr);
}

static noinline void __init copy_user_test(void)
{
	char *kmem;
	char __user *usermem;
	size_t size = 10;
	int unused;

	kmem = kmalloc(size, GFP_KERNEL);
	if (!kmem)
		return;

	usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
			    PROT_READ | PROT_WRITE | PROT_EXEC,
			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
	if (IS_ERR(usermem)) {
		pr_err("Failed to allocate user memory\n");
		kfree(kmem);
		return;
	}

	pr_info("out-of-bounds in copy_from_user()\n");
	unused = copy_from_user(kmem, usermem, size + 1);

	pr_info("out-of-bounds in copy_to_user()\n");
	unused = copy_to_user(usermem, kmem, size + 1);

	pr_info("out-of-bounds in __copy_from_user()\n");
	unused = __copy_from_user(kmem, usermem, size + 1);

	pr_info("out-of-bounds in __copy_to_user()\n");
	unused = __copy_to_user(usermem, kmem, size + 1);

	pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
	unused = __copy_from_user_inatomic(kmem, usermem, size + 1);

	pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
	unused = __copy_to_user_inatomic(usermem, kmem, size + 1);

	pr_info("out-of-bounds in strncpy_from_user()\n");
	unused = strncpy_from_user(kmem, usermem, size + 1);

	vm_munmap((unsigned long)usermem, PAGE_SIZE);
	kfree(kmem);
}

static noinline void __init use_after_scope_test(void)
{
	volatile char *volatile p;

	pr_info("use-after-scope on int\n");
	{
		int local = 0;

		p = (char *)&local;
	}
	p[0] = 1;
	p[3] = 1;

	pr_info("use-after-scope on array\n");
	{
		char local[1024] = {0};

		p = local;
	}
	p[0] = 1;
	p[1023] = 1;
}

static noinline void __init kasan_alloca_oob_left(void)
{
	volatile int i = 10;
	char alloca_array[i];
	char *p = alloca_array - 1;

	pr_info("out-of-bounds to left on alloca\n");
	*(volatile char *)p;
}

static noinline void __init kasan_alloca_oob_right(void)
{
	volatile int i = 10;
	char alloca_array[i];
	char *p = alloca_array + i;

	pr_info("out-of-bounds to right on alloca\n");
	*(volatile char *)p;
}

static noinline void __init kmem_cache_double_free(void)
{
	char *p;
	size_t size = 200;
	struct kmem_cache *cache;

	cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
	if (!cache) {
		pr_err("Cache allocation failed\n");
		return;
	}
	pr_info("double-free on heap object\n");
	p = kmem_cache_alloc(cache, GFP_KERNEL);
	if (!p) {
		pr_err("Allocation failed\n");
		kmem_cache_destroy(cache);
		return;
	}

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

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

	cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
				  NULL);
	if (!cache) {
		pr_err("Cache allocation failed\n");
		return;
	}
	pr_info("invalid-free of heap object\n");
	p = kmem_cache_alloc(cache, GFP_KERNEL);
	if (!p) {
		pr_err("Allocation failed\n");
		kmem_cache_destroy(cache);
		return;
	}

	/* Trigger invalid free, the object doesn't get freed */
	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 noinline void __init kasan_memchr(void)
{
	char *ptr;
	size_t size = 24;

	pr_info("out-of-bounds in memchr\n");
	ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
	if (!ptr)
		return;

	memchr(ptr, '1', size + 1);
	kfree(ptr);
}

static noinline void __init kasan_memcmp(void)
{
	char *ptr;
	size_t size = 24;
	int arr[9];

	pr_info("out-of-bounds in memcmp\n");
	ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
	if (!ptr)
		return;

	memset(arr, 0, sizeof(arr));
	memcmp(ptr, arr, size+1);
	kfree(ptr);
}

static noinline void __init kasan_strings(void)
{
	char *ptr;
	size_t size = 24;

	pr_info("use-after-free in strchr\n");
	ptr = kmalloc(size, GFP_KERNEL | __GFP_ZERO);
	if (!ptr)
		return;

	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;
	strchr(ptr, '1');

	pr_info("use-after-free in strrchr\n");
	strrchr(ptr, '1');

	pr_info("use-after-free in strcmp\n");
	strcmp(ptr, "2");

	pr_info("use-after-free in strncmp\n");
	strncmp(ptr, "2", 1);

	pr_info("use-after-free in strlen\n");
	strlen(ptr);

	pr_info("use-after-free in strnlen\n");
	strnlen(ptr, 1);
}

static int __init kmalloc_tests_init(void)
{
	/*
	 * Temporarily enable multi-shot mode. Otherwise, we'd only get a
	 * report for the first case.
	 */
	bool multishot = kasan_save_enable_multi_shot();

	kmalloc_oob_right();
	kmalloc_oob_left();
	kmalloc_node_oob_right();
#ifdef CONFIG_SLUB
	kmalloc_pagealloc_oob_right();
	kmalloc_pagealloc_uaf();
	kmalloc_pagealloc_invalid_free();
#endif
	kmalloc_large_oob_right();
	kmalloc_oob_krealloc_more();
	kmalloc_oob_krealloc_less();
	kmalloc_oob_16();
	kmalloc_oob_in_memset();
	kmalloc_oob_memset_2();
	kmalloc_oob_memset_4();
	kmalloc_oob_memset_8();
	kmalloc_oob_memset_16();
	kmalloc_uaf();
	kmalloc_uaf_memset();
	kmalloc_uaf2();
	kmem_cache_oob();
	memcg_accounted_kmem_cache();
	kasan_stack_oob();
	kasan_global_oob();
	kasan_alloca_oob_left();
	kasan_alloca_oob_right();
	ksize_unpoisons_memory();
	copy_user_test();
	use_after_scope_test();
	kmem_cache_double_free();
	kmem_cache_invalid_free();
	kasan_memchr();
	kasan_memcmp();
	kasan_strings();

	kasan_restore_multi_shot(multishot);

	return -EAGAIN;
}

module_init(kmalloc_tests_init);
MODULE_LICENSE("GPL");
Commit	Line	Data
3f15801c AR	1	/*
	2	*
	3	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
	4	* Author: Andrey Ryabinin <[email protected]>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11
	12	#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
	13
0386bf38	14	#include <linux/delay.h>
3f15801c	15	#include <linux/kernel.h>
eae08dca AR	16	#include <linux/mman.h>
eae08dca AR	17	#include <linux/mm.h>
3f15801c AR	18	#include <linux/printk.h>
	19	#include <linux/slab.h>
	20	#include <linux/string.h>
eae08dca	21	#include <linux/uaccess.h>
3f15801c	22	#include <linux/module.h>
b0845ce5	23	#include <linux/kasan.h>
3f15801c	24
828347f8 DV	25	/*
	26	* Note: test functions are marked noinline so that their names appear in
	27	* reports.
	28	*/
	29
3f15801c AR	30	static noinline void __init kmalloc_oob_right(void)
	31	{
	32	char *ptr;
	33	size_t size = 123;
	34
	35	pr_info("out-of-bounds to right\n");
	36	ptr = kmalloc(size, GFP_KERNEL);
	37	if (!ptr) {
	38	pr_err("Allocation failed\n");
	39	return;
	40	}
	41
	42	ptr[size] = 'x';
	43	kfree(ptr);
	44	}
	45
	46	static noinline void __init kmalloc_oob_left(void)
	47	{
	48	char *ptr;
	49	size_t size = 15;
	50
	51	pr_info("out-of-bounds to left\n");
	52	ptr = kmalloc(size, GFP_KERNEL);
	53	if (!ptr) {
	54	pr_err("Allocation failed\n");
	55	return;
	56	}
	57
	58	ptr = (ptr - 1);
	59	kfree(ptr);
	60	}
	61
	62	static noinline void __init kmalloc_node_oob_right(void)
	63	{
	64	char *ptr;
	65	size_t size = 4096;
	66
	67	pr_info("kmalloc_node(): out-of-bounds to right\n");
	68	ptr = kmalloc_node(size, GFP_KERNEL, 0);
	69	if (!ptr) {
	70	pr_err("Allocation failed\n");
	71	return;
	72	}
	73
	74	ptr[size] = 0;
	75	kfree(ptr);
	76	}
	77
e6e8379c AP	78	#ifdef CONFIG_SLUB
e6e8379c AP	79	static noinline void __init kmalloc_pagealloc_oob_right(void)
3f15801c AR	80	{
	81	char *ptr;
	82	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
	83
e6e8379c AP	84	/* Allocate a chunk that does not fit into a SLUB cache to trigger
	85	* the page allocator fallback.
	86	*/
	87	pr_info("kmalloc pagealloc allocation: out-of-bounds to right\n");
	88	ptr = kmalloc(size, GFP_KERNEL);
	89	if (!ptr) {
	90	pr_err("Allocation failed\n");
	91	return;
	92	}
	93
	94	ptr[size] = 0;
	95	kfree(ptr);
	96	}
47adccce DV	97
	98	static noinline void __init kmalloc_pagealloc_uaf(void)
	99	{
	100	char *ptr;
	101	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
	102
	103	pr_info("kmalloc pagealloc allocation: use-after-free\n");
	104	ptr = kmalloc(size, GFP_KERNEL);
	105	if (!ptr) {
	106	pr_err("Allocation failed\n");
	107	return;
	108	}
	109
	110	kfree(ptr);
	111	ptr[0] = 0;
	112	}
	113
	114	static noinline void __init kmalloc_pagealloc_invalid_free(void)
	115	{
	116	char *ptr;
	117	size_t size = KMALLOC_MAX_CACHE_SIZE + 10;
	118
	119	pr_info("kmalloc pagealloc allocation: invalid-free\n");
	120	ptr = kmalloc(size, GFP_KERNEL);
	121	if (!ptr) {
	122	pr_err("Allocation failed\n");
	123	return;
	124	}
	125
	126	kfree(ptr + 1);
	127	}
e6e8379c AP	128	#endif
	129
	130	static noinline void __init kmalloc_large_oob_right(void)
	131	{
	132	char *ptr;
	133	size_t size = KMALLOC_MAX_CACHE_SIZE - 256;
	134	/* Allocate a chunk that is large enough, but still fits into a slab
	135	* and does not trigger the page allocator fallback in SLUB.
	136	*/
3f15801c AR	137	pr_info("kmalloc large allocation: out-of-bounds to right\n");
	138	ptr = kmalloc(size, GFP_KERNEL);
	139	if (!ptr) {
	140	pr_err("Allocation failed\n");
	141	return;
	142	}
	143
	144	ptr[size] = 0;
	145	kfree(ptr);
	146	}
	147
	148	static noinline void __init kmalloc_oob_krealloc_more(void)
	149	{
	150	char ptr1, ptr2;
	151	size_t size1 = 17;
	152	size_t size2 = 19;
	153
	154	pr_info("out-of-bounds after krealloc more\n");
	155	ptr1 = kmalloc(size1, GFP_KERNEL);
	156	ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
	157	if (!ptr1 \|\| !ptr2) {
	158	pr_err("Allocation failed\n");
	159	kfree(ptr1);
	160	return;
	161	}
	162
	163	ptr2[size2] = 'x';
	164	kfree(ptr2);
	165	}
	166
	167	static noinline void __init kmalloc_oob_krealloc_less(void)
	168	{
	169	char ptr1, ptr2;
	170	size_t size1 = 17;
	171	size_t size2 = 15;
	172
	173	pr_info("out-of-bounds after krealloc less\n");
	174	ptr1 = kmalloc(size1, GFP_KERNEL);
	175	ptr2 = krealloc(ptr1, size2, GFP_KERNEL);
	176	if (!ptr1 \|\| !ptr2) {
	177	pr_err("Allocation failed\n");
	178	kfree(ptr1);
	179	return;
	180	}
6b4a35fc	181	ptr2[size2] = 'x';
3f15801c AR	182	kfree(ptr2);
	183	}
	184
	185	static noinline void __init kmalloc_oob_16(void)
	186	{
	187	struct {
	188	u64 words[2];
	189	} ptr1, ptr2;
	190
	191	pr_info("kmalloc out-of-bounds for 16-bytes access\n");
	192	ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL);
	193	ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL);
	194	if (!ptr1 \|\| !ptr2) {
	195	pr_err("Allocation failed\n");
	196	kfree(ptr1);
	197	kfree(ptr2);
	198	return;
	199	}
	200	ptr1 = ptr2;
	201	kfree(ptr1);
	202	kfree(ptr2);
	203	}
	204
f523e737 WL	205	static noinline void __init kmalloc_oob_memset_2(void)
	206	{
	207	char *ptr;
	208	size_t size = 8;
	209
	210	pr_info("out-of-bounds in memset2\n");
	211	ptr = kmalloc(size, GFP_KERNEL);
	212	if (!ptr) {
	213	pr_err("Allocation failed\n");
	214	return;
	215	}
	216
	217	memset(ptr+7, 0, 2);
	218	kfree(ptr);
	219	}
	220
	221	static noinline void __init kmalloc_oob_memset_4(void)
	222	{
	223	char *ptr;
	224	size_t size = 8;
	225
	226	pr_info("out-of-bounds in memset4\n");
	227	ptr = kmalloc(size, GFP_KERNEL);
	228	if (!ptr) {
	229	pr_err("Allocation failed\n");
	230	return;
	231	}
	232
	233	memset(ptr+5, 0, 4);
	234	kfree(ptr);
	235	}
	236
	237
	238	static noinline void __init kmalloc_oob_memset_8(void)
	239	{
	240	char *ptr;
	241	size_t size = 8;
	242
	243	pr_info("out-of-bounds in memset8\n");
	244	ptr = kmalloc(size, GFP_KERNEL);
	245	if (!ptr) {
	246	pr_err("Allocation failed\n");
	247	return;
	248	}
	249
	250	memset(ptr+1, 0, 8);
	251	kfree(ptr);
	252	}
	253
	254	static noinline void __init kmalloc_oob_memset_16(void)
	255	{
	256	char *ptr;
	257	size_t size = 16;
	258
	259	pr_info("out-of-bounds in memset16\n");
	260	ptr = kmalloc(size, GFP_KERNEL);
	261	if (!ptr) {
	262	pr_err("Allocation failed\n");
	263	return;
	264	}
	265
	266	memset(ptr+1, 0, 16);
	267	kfree(ptr);
	268	}
269
3f15801c AR	270	static noinline void __init kmalloc_oob_in_memset(void)
	271	{
	272	char *ptr;
	273	size_t size = 666;
	274
	275	pr_info("out-of-bounds in memset\n");
	276	ptr = kmalloc(size, GFP_KERNEL);
	277	if (!ptr) {
	278	pr_err("Allocation failed\n");
	279	return;
	280	}
	281
	282	memset(ptr, 0, size+5);
	283	kfree(ptr);
	284	}
	285
	286	static noinline void __init kmalloc_uaf(void)
	287	{
	288	char *ptr;
	289	size_t size = 10;
	290
	291	pr_info("use-after-free\n");
	292	ptr = kmalloc(size, GFP_KERNEL);
	293	if (!ptr) {
	294	pr_err("Allocation failed\n");
	295	return;
	296	}
	297
	298	kfree(ptr);
	299	*(ptr + 8) = 'x';
	300	}
	301
	302	static noinline void __init kmalloc_uaf_memset(void)
	303	{
	304	char *ptr;
	305	size_t size = 33;
	306
	307	pr_info("use-after-free in memset\n");
	308	ptr = kmalloc(size, GFP_KERNEL);
	309	if (!ptr) {
	310	pr_err("Allocation failed\n");
	311	return;
	312	}
	313
	314	kfree(ptr);
	315	memset(ptr, 0, size);
	316	}
	317
	318	static noinline void __init kmalloc_uaf2(void)
	319	{
	320	char ptr1, ptr2;
	321	size_t size = 43;
	322
	323	pr_info("use-after-free after another kmalloc\n");
	324	ptr1 = kmalloc(size, GFP_KERNEL);
	325	if (!ptr1) {
	326	pr_err("Allocation failed\n");
	327	return;
	328	}
	329
	330	kfree(ptr1);
	331	ptr2 = kmalloc(size, GFP_KERNEL);
	332	if (!ptr2) {
	333	pr_err("Allocation failed\n");
334	return;
335	}
336
337	ptr1[40] = 'x';
9dcadd38 AP	338	if (ptr1 == ptr2)
9dcadd38 AP	339	pr_err("Could not detect use-after-free: ptr1 == ptr2\n");
3f15801c AR	340	kfree(ptr2);
	341	}
	342
	343	static noinline void __init kmem_cache_oob(void)
	344	{
	345	char *p;
	346	size_t size = 200;
	347	struct kmem_cache *cache = kmem_cache_create("test_cache",
	348	size, 0,
	349	0, NULL);
	350	if (!cache) {
	351	pr_err("Cache allocation failed\n");
	352	return;
	353	}
	354	pr_info("out-of-bounds in kmem_cache_alloc\n");
	355	p = kmem_cache_alloc(cache, GFP_KERNEL);
	356	if (!p) {
	357	pr_err("Allocation failed\n");
	358	kmem_cache_destroy(cache);
	359	return;
	360	}
	361
	362	*p = p[size];
	363	kmem_cache_free(cache, p);
	364	kmem_cache_destroy(cache);
	365	}
	366
0386bf38 GT	367	static noinline void __init memcg_accounted_kmem_cache(void)
	368	{
	369	int i;
	370	char *p;
	371	size_t size = 200;
	372	struct kmem_cache *cache;
	373
	374	cache = kmem_cache_create("test_cache", size, 0, SLAB_ACCOUNT, NULL);
	375	if (!cache) {
	376	pr_err("Cache allocation failed\n");
	377	return;
	378	}
	379
	380	pr_info("allocate memcg accounted object\n");
	381	/*
	382	* Several allocations with a delay to allow for lazy per memcg kmem
	383	* cache creation.
	384	*/
	385	for (i = 0; i < 5; i++) {
	386	p = kmem_cache_alloc(cache, GFP_KERNEL);
dc2bf000	387	if (!p)
0386bf38	388	goto free_cache;
dc2bf000	389
0386bf38 GT	390	kmem_cache_free(cache, p);
	391	msleep(100);
	392	}
	393
	394	free_cache:
	395	kmem_cache_destroy(cache);
	396	}
	397
3f15801c AR	398	static char global_array[10];
	399
	400	static noinline void __init kasan_global_oob(void)
	401	{
	402	volatile int i = 3;
	403	char *p = &global_array[ARRAY_SIZE(global_array) + i];
	404
	405	pr_info("out-of-bounds global variable\n");
	406	(volatile char )p;
	407	}
	408
	409	static noinline void __init kasan_stack_oob(void)
	410	{
	411	char stack_array[10];
	412	volatile int i = 0;
	413	char *p = &stack_array[ARRAY_SIZE(stack_array) + i];
	414
	415	pr_info("out-of-bounds on stack\n");
	416	(volatile char )p;
	417	}
	418
96fe805f AP	419	static noinline void __init ksize_unpoisons_memory(void)
	420	{
	421	char *ptr;
48c23239	422	size_t size = 123, real_size;
96fe805f AP	423
	424	pr_info("ksize() unpoisons the whole allocated chunk\n");
	425	ptr = kmalloc(size, GFP_KERNEL);
	426	if (!ptr) {
	427	pr_err("Allocation failed\n");
	428	return;
	429	}
	430	real_size = ksize(ptr);
	431	/* This access doesn't trigger an error. */
	432	ptr[size] = 'x';
	433	/* This one does. */
	434	ptr[real_size] = 'y';
	435	kfree(ptr);
	436	}
	437
eae08dca AR	438	static noinline void __init copy_user_test(void)
	439	{
	440	char *kmem;
	441	char __user *usermem;
	442	size_t size = 10;
	443	int unused;
	444
	445	kmem = kmalloc(size, GFP_KERNEL);
	446	if (!kmem)
	447	return;
	448
	449	usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
	450	PROT_READ \| PROT_WRITE \| PROT_EXEC,
	451	MAP_ANONYMOUS \| MAP_PRIVATE, 0);
	452	if (IS_ERR(usermem)) {
	453	pr_err("Failed to allocate user memory\n");
	454	kfree(kmem);
	455	return;
	456	}
	457
	458	pr_info("out-of-bounds in copy_from_user()\n");
	459	unused = copy_from_user(kmem, usermem, size + 1);
	460
	461	pr_info("out-of-bounds in copy_to_user()\n");
	462	unused = copy_to_user(usermem, kmem, size + 1);
	463
	464	pr_info("out-of-bounds in __copy_from_user()\n");
	465	unused = __copy_from_user(kmem, usermem, size + 1);
	466
	467	pr_info("out-of-bounds in __copy_to_user()\n");
	468	unused = __copy_to_user(usermem, kmem, size + 1);
	469
	470	pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
	471	unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
	472
	473	pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
	474	unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
	475
	476	pr_info("out-of-bounds in strncpy_from_user()\n");
	477	unused = strncpy_from_user(kmem, usermem, size + 1);
	478
	479	vm_munmap((unsigned long)usermem, PAGE_SIZE);
	480	kfree(kmem);
	481	}
	482
828347f8 DV	483	static noinline void __init use_after_scope_test(void)
	484	{
	485	volatile char *volatile p;
	486
	487	pr_info("use-after-scope on int\n");
	488	{
	489	int local = 0;
	490
	491	p = (char *)&local;
	492	}
	493	p[0] = 1;
	494	p[3] = 1;
	495
	496	pr_info("use-after-scope on array\n");
	497	{
	498	char local[1024] = {0};
	499
	500	p = local;
	501	}
	502	p[0] = 1;
	503	p[1023] = 1;
	504	}
	505
00a14294 PL	506	static noinline void __init kasan_alloca_oob_left(void)
	507	{
	508	volatile int i = 10;
	509	char alloca_array[i];
	510	char *p = alloca_array - 1;
	511
	512	pr_info("out-of-bounds to left on alloca\n");
	513	(volatile char )p;
	514	}
	515
	516	static noinline void __init kasan_alloca_oob_right(void)
	517	{
	518	volatile int i = 10;
	519	char alloca_array[i];
	520	char *p = alloca_array + i;
	521
	522	pr_info("out-of-bounds to right on alloca\n");
	523	(volatile char )p;
	524	}
	525
b1d57289 DV	526	static noinline void __init kmem_cache_double_free(void)
	527	{
	528	char *p;
	529	size_t size = 200;
	530	struct kmem_cache *cache;
	531
	532	cache = kmem_cache_create("test_cache", size, 0, 0, NULL);
	533	if (!cache) {
	534	pr_err("Cache allocation failed\n");
	535	return;
	536	}
	537	pr_info("double-free on heap object\n");
	538	p = kmem_cache_alloc(cache, GFP_KERNEL);
	539	if (!p) {
	540	pr_err("Allocation failed\n");
	541	kmem_cache_destroy(cache);
	542	return;
	543	}
	544
	545	kmem_cache_free(cache, p);
	546	kmem_cache_free(cache, p);
	547	kmem_cache_destroy(cache);
	548	}
	549
	550	static noinline void __init kmem_cache_invalid_free(void)
	551	{
	552	char *p;
	553	size_t size = 200;
	554	struct kmem_cache *cache;
	555
	556	cache = kmem_cache_create("test_cache", size, 0, SLAB_TYPESAFE_BY_RCU,
	557	NULL);
	558	if (!cache) {
	559	pr_err("Cache allocation failed\n");
	560	return;
	561	}
	562	pr_info("invalid-free of heap object\n");
	563	p = kmem_cache_alloc(cache, GFP_KERNEL);
	564	if (!p) {
	565	pr_err("Allocation failed\n");
	566	kmem_cache_destroy(cache);
	567	return;
	568	}
	569
91c93ed0	570	/* Trigger invalid free, the object doesn't get freed */
b1d57289	571	kmem_cache_free(cache, p + 1);
91c93ed0 AK	572
	573	/*
	574	* Properly free the object to prevent the "Objects remaining in
	575	* test_cache on __kmem_cache_shutdown" BUG failure.
	576	*/
	577	kmem_cache_free(cache, p);
	578
b1d57289 DV	579	kmem_cache_destroy(cache);
	580	}
	581
0c96350a AR	582	static noinline void __init kasan_memchr(void)
	583	{
	584	char *ptr;
	585	size_t size = 24;
	586
	587	pr_info("out-of-bounds in memchr\n");
	588	ptr = kmalloc(size, GFP_KERNEL \| __GFP_ZERO);
	589	if (!ptr)
	590	return;
	591
	592	memchr(ptr, '1', size + 1);
	593	kfree(ptr);
	594	}
	595
	596	static noinline void __init kasan_memcmp(void)
	597	{
	598	char *ptr;
	599	size_t size = 24;
	600	int arr[9];
	601
	602	pr_info("out-of-bounds in memcmp\n");
	603	ptr = kmalloc(size, GFP_KERNEL \| __GFP_ZERO);
	604	if (!ptr)
	605	return;
	606
	607	memset(arr, 0, sizeof(arr));
	608	memcmp(ptr, arr, size+1);
	609	kfree(ptr);
	610	}
	611
	612	static noinline void __init kasan_strings(void)
	613	{
	614	char *ptr;
	615	size_t size = 24;
	616
	617	pr_info("use-after-free in strchr\n");
	618	ptr = kmalloc(size, GFP_KERNEL \| __GFP_ZERO);
	619	if (!ptr)
	620	return;
	621
	622	kfree(ptr);
	623
	624	/*
	625	* Try to cause only 1 invalid access (less spam in dmesg).
	626	* For that we need ptr to point to zeroed byte.
	627	* Skip metadata that could be stored in freed object so ptr
	628	* will likely point to zeroed byte.
	629	*/
	630	ptr += 16;
	631	strchr(ptr, '1');
	632
	633	pr_info("use-after-free in strrchr\n");
	634	strrchr(ptr, '1');
	635
	636	pr_info("use-after-free in strcmp\n");
	637	strcmp(ptr, "2");
	638
	639	pr_info("use-after-free in strncmp\n");
	640	strncmp(ptr, "2", 1);
	641
	642	pr_info("use-after-free in strlen\n");
	643	strlen(ptr);
	644
	645	pr_info("use-after-free in strnlen\n");
646	strnlen(ptr, 1);
647	}
648
3f15801c AR	649	static int __init kmalloc_tests_init(void)
3f15801c AR	650	{
b0845ce5 MR	651	/*
	652	* Temporarily enable multi-shot mode. Otherwise, we'd only get a
	653	* report for the first case.
	654	*/
	655	bool multishot = kasan_save_enable_multi_shot();
	656
3f15801c AR	657	kmalloc_oob_right();
	658	kmalloc_oob_left();
	659	kmalloc_node_oob_right();
e6e8379c AP	660	#ifdef CONFIG_SLUB
e6e8379c AP	661	kmalloc_pagealloc_oob_right();
47adccce DV	662	kmalloc_pagealloc_uaf();
47adccce DV	663	kmalloc_pagealloc_invalid_free();
e6e8379c	664	#endif
9789d8e0	665	kmalloc_large_oob_right();
3f15801c AR	666	kmalloc_oob_krealloc_more();
	667	kmalloc_oob_krealloc_less();
	668	kmalloc_oob_16();
	669	kmalloc_oob_in_memset();
f523e737 WL	670	kmalloc_oob_memset_2();
	671	kmalloc_oob_memset_4();
	672	kmalloc_oob_memset_8();
	673	kmalloc_oob_memset_16();
3f15801c AR	674	kmalloc_uaf();
	675	kmalloc_uaf_memset();
	676	kmalloc_uaf2();
	677	kmem_cache_oob();
0386bf38	678	memcg_accounted_kmem_cache();
3f15801c AR	679	kasan_stack_oob();
3f15801c AR	680	kasan_global_oob();
00a14294 PL	681	kasan_alloca_oob_left();
00a14294 PL	682	kasan_alloca_oob_right();
96fe805f	683	ksize_unpoisons_memory();
eae08dca	684	copy_user_test();
828347f8	685	use_after_scope_test();
b1d57289 DV	686	kmem_cache_double_free();
b1d57289 DV	687	kmem_cache_invalid_free();
0c96350a AR	688	kasan_memchr();
	689	kasan_memcmp();
	690	kasan_strings();
b0845ce5 MR	691
	692	kasan_restore_multi_shot(multishot);
	693
3f15801c AR	694	return -EAGAIN;
	695	}
	696
	697	module_init(kmalloc_tests_init);
	698	MODULE_LICENSE("GPL");