xref: /openbsd-src/regress/lib/libc/sys/t_setuid.c (revision 49a6e16f2c2c8e509184b1f777366d1a6f337e1c)
1 /*	$OpenBSD: t_setuid.c,v 1.2 2021/12/13 16:56:48 deraadt Exp $	*/
2 /* $NetBSD: t_setuid.c,v 1.1 2011/07/07 06:57:54 jruoho Exp $ */
3 
4 /*-
5  * Copyright (c) 2011 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Jukka Ruohonen.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include "macros.h"
34 
35 #include <sys/wait.h>
36 
37 #include "atf-c.h"
38 #include <errno.h>
39 #include <pwd.h>
40 #include <stdlib.h>
41 #include <unistd.h>
42 
43 ATF_TC(setuid_perm);
ATF_TC_HEAD(setuid_perm,tc)44 ATF_TC_HEAD(setuid_perm, tc)
45 {
46 	atf_tc_set_md_var(tc, "descr", "Test setuid(0) as normal user");
47 	atf_tc_set_md_var(tc, "require.user", "unprivileged");
48 }
49 
ATF_TC_BODY(setuid_perm,tc)50 ATF_TC_BODY(setuid_perm, tc)
51 {
52 	errno = 0;
53 
54 	ATF_REQUIRE(setuid(0) == -1);
55 	ATF_REQUIRE(errno == EPERM);
56 }
57 
58 ATF_TC(setuid_real);
ATF_TC_HEAD(setuid_real,tc)59 ATF_TC_HEAD(setuid_real, tc)
60 {
61 	atf_tc_set_md_var(tc, "descr", "Test setuid(2) with real UID");
62 }
63 
ATF_TC_BODY(setuid_real,tc)64 ATF_TC_BODY(setuid_real, tc)
65 {
66 	uid_t uid = getuid();
67 
68 	ATF_REQUIRE(setuid(uid) == 0);
69 
70 	ATF_REQUIRE(getuid() == uid);
71 	ATF_REQUIRE(geteuid() == uid);
72 }
73 
74 ATF_TC(setuid_root);
ATF_TC_HEAD(setuid_root,tc)75 ATF_TC_HEAD(setuid_root, tc)
76 {
77 	atf_tc_set_md_var(tc, "descr", "A basic test of setuid(2)");
78 	atf_tc_set_md_var(tc, "require.user", "root");
79 }
80 
ATF_TC_BODY(setuid_root,tc)81 ATF_TC_BODY(setuid_root, tc)
82 {
83 	struct passwd *pw;
84 	int rv, sta;
85 	pid_t pid;
86 	uid_t uid;
87 
88 	while ((pw = getpwent()) != NULL) {
89 
90 		pid = fork();
91 		ATF_REQUIRE(pid >= 0);
92 
93 		if (pid == 0) {
94 
95 			rv = setuid(pw->pw_uid);
96 
97 			if (rv != 0)
98 				_exit(EXIT_FAILURE);
99 
100 			uid = getuid();
101 
102 			if (uid != pw->pw_uid)
103 				_exit(EXIT_FAILURE);
104 
105 			_exit(EXIT_SUCCESS);
106 		}
107 
108 		(void)wait(&sta);
109 
110 		if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
111 			atf_tc_fail("failed to change UID to %u", pw->pw_uid);
112 	}
113 }
114 
ATF_TP_ADD_TCS(tp)115 ATF_TP_ADD_TCS(tp)
116 {
117 
118 	ATF_TP_ADD_TC(tp, setuid_perm);
119 	ATF_TP_ADD_TC(tp, setuid_real);
120 	ATF_TP_ADD_TC(tp, setuid_root);
121 
122 	return atf_no_error();
123 }
124