1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 *
 4 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
 5 * Author: Andrey Ryabinin <a.ryabinin@samsung.com>
 6 */
 7
 8#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
 9
10#include <linux/mman.h>
11#include <linux/module.h>
12#include <linux/printk.h>
13#include <linux/slab.h>
14#include <linux/uaccess.h>
15
16#include "kasan.h"
17
18static noinline void __init copy_user_test(void)
19{
20	char *kmem;
21	char __user *usermem;
22	size_t size = 128 - KASAN_GRANULE_SIZE;
23	int __maybe_unused unused;
24
25	kmem = kmalloc(size, GFP_KERNEL);
26	if (!kmem)
27		return;
28
29	usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
30			    PROT_READ | PROT_WRITE | PROT_EXEC,
31			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
32	if (IS_ERR(usermem)) {
33		pr_err("Failed to allocate user memory\n");
34		kfree(kmem);
35		return;
36	}
37
38	OPTIMIZER_HIDE_VAR(size);
39
40	pr_info("out-of-bounds in copy_from_user()\n");
41	unused = copy_from_user(kmem, usermem, size + 1);
42
43	pr_info("out-of-bounds in copy_to_user()\n");
44	unused = copy_to_user(usermem, kmem, size + 1);
45
46	pr_info("out-of-bounds in __copy_from_user()\n");
47	unused = __copy_from_user(kmem, usermem, size + 1);
48
49	pr_info("out-of-bounds in __copy_to_user()\n");
50	unused = __copy_to_user(usermem, kmem, size + 1);
51
52	pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
53	unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
54
55	pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
56	unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
57
58	pr_info("out-of-bounds in strncpy_from_user()\n");
59	unused = strncpy_from_user(kmem, usermem, size + 1);
60
61	vm_munmap((unsigned long)usermem, PAGE_SIZE);
62	kfree(kmem);
63}
64
65static int __init test_kasan_module_init(void)
66{
67	/*
68	 * Temporarily enable multi-shot mode. Otherwise, KASAN would only
69	 * report the first detected bug and panic the kernel if panic_on_warn
70	 * is enabled.
71	 */
72	bool multishot = kasan_save_enable_multi_shot();
73
74	copy_user_test();
75
76	kasan_restore_multi_shot(multishot);
77	return -EAGAIN;
78}
79
80module_init(test_kasan_module_init);
81MODULE_LICENSE("GPL");