1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) International Business Machines Corp., 2001
4 * Ported by John George
5 * Copyright (C) 2021 SUSE LLC <mdoucha@suse.cz>
6 */
7
8 /*\
9 * [Description]
10 *
11 * Test the setreuid() feature, verifying the role of the saved-set-uid
12 * and setreuid's effect on it.
13 */
14
15 #include <sys/types.h>
16 #include <pwd.h>
17 #include <stdlib.h>
18
19 #include "tst_test.h"
20 #include "tst_uid.h"
21 #include "compat_tst_16.h"
22
23 static uid_t root_uid, nobody_uid, main_uid, other_uid, neg_one = -1;
24
25 struct test_data_t {
26 uid_t *real_uid;
27 uid_t *eff_uid;
28 int exp_ret;
29 uid_t *exp_real_uid;
30 uid_t *exp_eff_uid;
31 uid_t *exp_sav_uid;
32 const char *test_msg;
33 } test_data[] = {
34 {&nobody_uid, &root_uid, 0, &nobody_uid, &root_uid, &root_uid,
35 "setreuid(nobody, root)"},
36 {&neg_one, &nobody_uid, 0, &nobody_uid, &nobody_uid, &root_uid,
37 "setreuid(-1, nobody)"},
38 {&neg_one, &root_uid, 0, &nobody_uid, &root_uid, &root_uid,
39 "setreuid(-1, root)"},
40 {&main_uid, &neg_one, 0, &main_uid, &root_uid, &root_uid,
41 "setreuid(main, -1)"},
42 {&neg_one, &other_uid, 0, &main_uid, &other_uid, &other_uid,
43 "setreuid(-1, other)"},
44 {&neg_one, &root_uid, -1, &main_uid, &other_uid, &other_uid,
45 "setreuid(-1, root)"},
46 {&neg_one, &nobody_uid, -1, &main_uid, &other_uid, &other_uid,
47 "setreuid(-1, nobody)"},
48 {&neg_one, &main_uid, 0, &main_uid, &main_uid, &other_uid,
49 "setreuid(-1, main)"},
50 {&neg_one, &other_uid, 0, &main_uid, &other_uid, &other_uid,
51 "setreuid(-1, other)"},
52 {&other_uid, &main_uid, 0, &other_uid, &main_uid, &main_uid,
53 "setreuid(other, main)"},
54 {&neg_one, &other_uid, 0, &other_uid, &other_uid, &main_uid,
55 "setreuid(-1, other)"},
56 {&neg_one, &main_uid, 0, &other_uid, &main_uid, &main_uid,
57 "setreuid(-1, main)"},
58 {&main_uid, &neg_one, 0, &main_uid, &main_uid, &main_uid,
59 "setreuid(main, -1)"},
60 {&neg_one, &other_uid, -1, &main_uid, &main_uid, &main_uid,
61 "setreuid(-1, other)"},
62 };
63
setup(void)64 static void setup(void)
65 {
66 uid_t test_users[3];
67 struct passwd *pw;
68
69 root_uid = getuid();
70 pw = SAFE_GETPWNAM("nobody");
71 nobody_uid = test_users[0] = pw->pw_uid;
72 tst_get_uids(test_users, 1, 3);
73 main_uid = test_users[1];
74 other_uid = test_users[2];
75
76 UID16_CHECK(root_uid, setreuid);
77 UID16_CHECK(nobody_uid, setreuid);
78 UID16_CHECK(main_uid, setreuid);
79 UID16_CHECK(other_uid, setreuid);
80
81 /* Make sure that saved UID is also set to root */
82 SAFE_SETUID(root_uid);
83 }
84
run_child(const struct test_data_t * tc)85 static void run_child(const struct test_data_t *tc)
86 {
87 if (tc->exp_ret) {
88 TST_EXP_FAIL(SETREUID(*tc->real_uid, *tc->eff_uid), EPERM,
89 "%s", tc->test_msg);
90 } else {
91 TST_EXP_PASS(SETREUID(*tc->real_uid, *tc->eff_uid), "%s",
92 tc->test_msg);
93 }
94
95 if (!TST_PASS)
96 return;
97
98 tst_check_resuid(tc->test_msg, *tc->exp_real_uid, *tc->exp_eff_uid,
99 *tc->exp_sav_uid);
100 }
101
run(void)102 static void run(void)
103 {
104 if (!SAFE_FORK()) {
105 unsigned int i;
106
107 for (i = 0; i < ARRAY_SIZE(test_data); i++)
108 run_child(test_data + i);
109
110 exit(0);
111 }
112
113 tst_reap_children();
114 }
115
116 static struct tst_test test = {
117 .test_all = run,
118 .setup = setup,
119 .needs_root = 1,
120 .forks_child = 1,
121 };
122