1 /// SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) International Business Machines Corp., 2001
4 */
5
6 /*
7 * Test Name: chmod05
8 *
9 * Test Description:
10 * Verify that, chmod(2) will succeed to change the mode of a directory
11 * but fails to set the setgid bit on it if invoked by non-root (uid != 0)
12 * process with the following constraints,
13 * - the process is the owner of the directory.
14 * - the effective group ID or one of the supplementary group ID's of the
15 * process is not equal to the group ID of the directory.
16 *
17 * Expected Result:
18 * chmod() should return value 0 on success and though succeeds to change
19 * the mode of a directory but fails to set setgid bit on it.
20 *
21 */
22
23 #ifndef _GNU_SOURCE
24 # define _GNU_SOURCE
25 #endif
26
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <fcntl.h>
32 #include <errno.h>
33 #include <string.h>
34 #include <signal.h>
35 #include <unistd.h>
36 #include <grp.h>
37 #include <pwd.h>
38
39 #include "tst_test.h"
40
41 #define MODE_RWX (mode_t)(S_IRWXU | S_IRWXG | S_IRWXO)
42 #define DIR_MODE (mode_t)(S_ISVTX | S_ISGID | S_IFDIR)
43 #define PERMS (mode_t)(MODE_RWX | DIR_MODE)
44 #define TESTDIR "testdir"
45
test_chmod(void)46 static void test_chmod(void)
47 {
48 struct stat stat_buf;
49 mode_t dir_mode;
50
51 TEST(chmod(TESTDIR, PERMS));
52 if (TST_RET == -1) {
53 tst_res(TFAIL, "chmod(%s, %#o) failed", TESTDIR, PERMS);
54 return;
55 }
56
57 SAFE_STAT(TESTDIR, &stat_buf);
58 dir_mode = stat_buf.st_mode;
59 if ((PERMS & ~S_ISGID) != dir_mode) {
60 tst_res(TFAIL, "%s: Incorrect modes 0%03o, "
61 "Expected 0%03o", TESTDIR, dir_mode,
62 PERMS & ~S_ISGID);
63 } else {
64 tst_res(TPASS, "Functionality of chmod(%s, %#o) successful",
65 TESTDIR, PERMS);
66 }
67 }
68
setup(void)69 static void setup(void)
70 {
71 struct passwd *nobody_u;
72 struct group *bin_gr;
73
74 nobody_u = SAFE_GETPWNAM("nobody");
75 bin_gr = SAFE_GETGRNAM("bin");
76
77 /*
78 * Create a test directory under temporary directory with specified
79 * mode permissions and change the gid of test directory to nobody's
80 * gid.
81 */
82 SAFE_MKDIR(TESTDIR, MODE_RWX);
83 if (setgroups(1, &nobody_u->pw_gid) == -1)
84 tst_brk(TBROK | TERRNO, "setgroups to nobody's gid failed");
85
86 SAFE_CHOWN(TESTDIR, nobody_u->pw_uid, bin_gr->gr_gid);
87
88 /* change to nobody:nobody */
89 SAFE_SETEGID(nobody_u->pw_gid);
90 SAFE_SETEUID(nobody_u->pw_uid);
91 }
92
93 static struct tst_test test = {
94 .needs_root = 1,
95 .needs_tmpdir = 1,
96 .setup = setup,
97 .test_all = test_chmod,
98 };
99