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 "../mm/kasan/kasan.h"
17
18#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_SHADOW_SCALE_SIZE)
19
20static noinline void __init copy_user_test(void)
21{
22	char *kmem;
23	char __user *usermem;
24	size_t size = 10;
25	int unused;
26
27	kmem = kmalloc(size, GFP_KERNEL);
28	if (!kmem)
29		return;
30
31	usermem = (char __user *)vm_mmap(NULL, 0, PAGE_SIZE,
32			    PROT_READ | PROT_WRITE | PROT_EXEC,
33			    MAP_ANONYMOUS | MAP_PRIVATE, 0);
34	if (IS_ERR(usermem)) {
35		pr_err("Failed to allocate user memory\n");
36		kfree(kmem);
37		return;
38	}
39
40	pr_info("out-of-bounds in copy_from_user()\n");
41	unused = copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
42
43	pr_info("out-of-bounds in copy_to_user()\n");
44	unused = copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF);
45
46	pr_info("out-of-bounds in __copy_from_user()\n");
47	unused = __copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
48
49	pr_info("out-of-bounds in __copy_to_user()\n");
50	unused = __copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF);
51
52	pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
53	unused = __copy_from_user_inatomic(kmem, usermem, size + 1 + OOB_TAG_OFF);
54
55	pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
56	unused = __copy_to_user_inatomic(usermem, kmem, size + 1 + OOB_TAG_OFF);
57
58	pr_info("out-of-bounds in strncpy_from_user()\n");
59	unused = strncpy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
60
61	vm_munmap((unsigned long)usermem, PAGE_SIZE);
62	kfree(kmem);
63}
64
65static struct kasan_rcu_info {
66	int i;
67	struct rcu_head rcu;
68} *global_rcu_ptr;
69
70static noinline void __init kasan_rcu_reclaim(struct rcu_head *rp)
71{
72	struct kasan_rcu_info *fp = container_of(rp,
73						struct kasan_rcu_info, rcu);
74
75	kfree(fp);
76	fp->i = 1;
77}
78
79static noinline void __init kasan_rcu_uaf(void)
80{
81	struct kasan_rcu_info *ptr;
82
83	pr_info("use-after-free in kasan_rcu_reclaim\n");
84	ptr = kmalloc(sizeof(struct kasan_rcu_info), GFP_KERNEL);
85	if (!ptr) {
86		pr_err("Allocation failed\n");
87		return;
88	}
89
90	global_rcu_ptr = rcu_dereference_protected(ptr, NULL);
91	call_rcu(&global_rcu_ptr->rcu, kasan_rcu_reclaim);
92}
93
94
95static int __init test_kasan_module_init(void)
96{
97	/*
98	 * Temporarily enable multi-shot mode. Otherwise, we'd only get a
99	 * report for the first case.
100	 */
101	bool multishot = kasan_save_enable_multi_shot();
102
103	copy_user_test();
104	kasan_rcu_uaf();
105
106	kasan_restore_multi_shot(multishot);
107	return -EAGAIN;
108}
109
110module_init(test_kasan_module_init);
111MODULE_LICENSE("GPL");
112