1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/*-
* Copyright (c) 2006 nCircle Network Security, Inc.
* All rights reserved.
*
* This software was developed by Robert N. M. Watson for the TrustedBSD
* Project under contract to nCircle Network Security, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY,
* INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
/*
* Test privilege check on /dev/io. By default, the permissions also protect
* against non-superuser access, so this program will modify permissions on
* /dev/io to allow group access for the wheel group, and revert the change
* on exit. This is not good for run-time security, but is necessary to test
* the checks properly.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include "main.h"
#define NEW_PERMS 0660
#define DEV_IO "/dev/io"
#define EXPECTED_PERMS 0600
static mode_t saved_perms;
static void
save_perms(void)
{
struct stat sb;
if (stat(DEV_IO, &sb) < 0)
err(-1, "save_perms: stat(%s)", DEV_IO);
saved_perms = sb.st_mode & ALLPERMS;
if (saved_perms != EXPECTED_PERMS)
err(-1, "save_perms: perms = 0%o; expected 0%o", saved_perms,
EXPECTED_PERMS);
}
static void
set_perms(void)
{
if (chmod(DEV_IO, NEW_PERMS) < 0)
err(-1, "set_perms: chmod(%s, 0%o)", DEV_IO, NEW_PERMS);
}
static void
restore_perms(void)
{
if (chmod(DEV_IO, saved_perms) < 0)
err(-1, "restore_perms: chmod(%s, 0%o)", DEV_IO, saved_perms);
}
static void
try_open(const char *test_case, uid_t uid, int expected)
{
int fd;
set_euid(uid);
fd = open(DEV_IO, O_RDONLY);
if (expected == 0) {
if (fd == -1) {
warn("try_open: %s open(%s) errno %d", DEV_IO,
test_case, errno);
goto out;
}
close(fd);
goto out;
}
if (fd >= 0) {
warn("try_open: %s open(%s) unexpected success", test_case,
DEV_IO);
close(fd);
goto out;
}
if (errno == expected)
goto out;
warn("try_open: %s open(%s) wrong errno %d, expected %d", DEV_IO,
test_case, errno, expected);
out:
set_euid(UID_ROOT);
}
void
priv_io(void)
{
assert_root();
save_perms();
try_open("root:0600", UID_ROOT, 0);
try_open("other", UID_OTHER, EACCES);
set_perms();
try_open("root:0660", UID_ROOT, 0);
try_open("other", UID_OTHER, EPERM);
restore_perms();
}
|
