Merge branch 'next' into for-linus
[firefly-linux-kernel-4.4.55.git] / lib / test_user_copy.c
1 /*
2  * Kernel module for testing copy_to/from_user infrastructure.
3  *
4  * Copyright 2013 Google Inc. All Rights Reserved
5  *
6  * Authors:
7  *      Kees Cook       <keescook@chromium.org>
8  *
9  * This software is licensed under the terms of the GNU General Public
10  * License version 2, as published by the Free Software Foundation, and
11  * may be copied, distributed, and modified under those terms.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  */
18
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21 #include <linux/mman.h>
22 #include <linux/module.h>
23 #include <linux/sched.h>
24 #include <linux/slab.h>
25 #include <linux/uaccess.h>
26 #include <linux/vmalloc.h>
27
28 #define test(condition, msg)            \
29 ({                                      \
30         int cond = (condition);         \
31         if (cond)                       \
32                 pr_warn("%s\n", msg);   \
33         cond;                           \
34 })
35
36 static int __init test_user_copy_init(void)
37 {
38         int ret = 0;
39         char *kmem;
40         char __user *usermem;
41         char *bad_usermem;
42         unsigned long user_addr;
43         unsigned long value = 0x5A;
44
45         kmem = kmalloc(PAGE_SIZE * 2, GFP_KERNEL);
46         if (!kmem)
47                 return -ENOMEM;
48
49         user_addr = vm_mmap(NULL, 0, PAGE_SIZE * 2,
50                             PROT_READ | PROT_WRITE | PROT_EXEC,
51                             MAP_ANONYMOUS | MAP_PRIVATE, 0);
52         if (user_addr >= (unsigned long)(TASK_SIZE)) {
53                 pr_warn("Failed to allocate user memory\n");
54                 kfree(kmem);
55                 return -ENOMEM;
56         }
57
58         usermem = (char __user *)user_addr;
59         bad_usermem = (char *)user_addr;
60
61         /* Legitimate usage: none of these should fail. */
62         ret |= test(copy_from_user(kmem, usermem, PAGE_SIZE),
63                     "legitimate copy_from_user failed");
64         ret |= test(copy_to_user(usermem, kmem, PAGE_SIZE),
65                     "legitimate copy_to_user failed");
66         ret |= test(get_user(value, (unsigned long __user *)usermem),
67                     "legitimate get_user failed");
68         ret |= test(put_user(value, (unsigned long __user *)usermem),
69                     "legitimate put_user failed");
70
71         /* Invalid usage: none of these should succeed. */
72         ret |= test(!copy_from_user(kmem, (char __user *)(kmem + PAGE_SIZE),
73                                     PAGE_SIZE),
74                     "illegal all-kernel copy_from_user passed");
75         ret |= test(!copy_from_user(bad_usermem, (char __user *)kmem,
76                                     PAGE_SIZE),
77                     "illegal reversed copy_from_user passed");
78         ret |= test(!copy_to_user((char __user *)kmem, kmem + PAGE_SIZE,
79                                   PAGE_SIZE),
80                     "illegal all-kernel copy_to_user passed");
81         ret |= test(!copy_to_user((char __user *)kmem, bad_usermem,
82                                   PAGE_SIZE),
83                     "illegal reversed copy_to_user passed");
84         ret |= test(!get_user(value, (unsigned long __user *)kmem),
85                     "illegal get_user passed");
86         ret |= test(!put_user(value, (unsigned long __user *)kmem),
87                     "illegal put_user passed");
88
89         vm_munmap(user_addr, PAGE_SIZE * 2);
90         kfree(kmem);
91
92         if (ret == 0) {
93                 pr_info("tests passed.\n");
94                 return 0;
95         }
96
97         return -EINVAL;
98 }
99
100 module_init(test_user_copy_init);
101
102 static void __exit test_user_copy_exit(void)
103 {
104         pr_info("unloaded.\n");
105 }
106
107 module_exit(test_user_copy_exit);
108
109 MODULE_AUTHOR("Kees Cook <keescook@chromium.org>");
110 MODULE_LICENSE("GPL");