1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) International Business Machines Corp., 2001
4 * 07/2001 Ported by Wayne Boyer
5 */
6
7 /*\
8 * [Description]
9 *
10 * Verify that, chown(2) succeeds to change the group of a file specified
11 * by path when called by non-root user with the following constraints:
12 *
13 * - euid of the process is equal to the owner of the file.
14 * - the intended gid is either egid, or one of the supplementary gids
15 * of the process.
16 *
17 * Also verify that chown() clears the setuid/setgid bits set on the file.
18 */
19
20 #include <pwd.h>
21
22 #include "tst_test.h"
23 #include "compat_tst_16.h"
24
25 #define FILE_MODE (S_IFREG|S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)
26 #define NEW_PERMS (S_IFREG|S_IRWXU|S_IRWXG|S_ISUID|S_ISGID)
27 #define FILENAME "chown03_testfile"
28
29 static struct passwd *ltpuser;
30
check_owner(struct stat * s,uid_t exp_uid,gid_t exp_gid)31 static void check_owner(struct stat *s, uid_t exp_uid, gid_t exp_gid)
32 {
33 if (s->st_uid != exp_uid || s->st_gid != exp_gid)
34 tst_res(TFAIL, "%s: wrong owner set to (uid=%d, gid=%d),"
35 " expected (uid=%d, gid=%d)",
36 FILENAME, s->st_uid, s->st_gid, exp_uid, exp_gid);
37 }
38
check_mode(struct stat * s,mode_t exp_mode)39 static void check_mode(struct stat *s, mode_t exp_mode)
40 {
41 if (s->st_mode != exp_mode)
42 tst_res(TFAIL, "%s: wrong mode permissions %#o, expected %#o",
43 FILENAME, s->st_mode, exp_mode);
44 }
45
run(void)46 static void run(void)
47 {
48 SAFE_SETEUID(0);
49 SAFE_CHOWN(FILENAME, -1, 0);
50 SAFE_CHMOD(FILENAME, NEW_PERMS);
51 SAFE_SETEUID(ltpuser->pw_uid);
52
53 uid_t uid;
54 gid_t gid;
55 UID16_CHECK((uid = geteuid()), "chown");
56 GID16_CHECK((gid = getegid()), "chown");
57
58 struct stat stat_buf;
59 SAFE_STAT(FILENAME, &stat_buf);
60 check_owner(&stat_buf, uid, 0);
61 check_mode(&stat_buf, NEW_PERMS);
62
63 TST_EXP_PASS(CHOWN(FILENAME, -1, gid), "chown(%s, %d, %d)",
64 FILENAME, -1, gid);
65 SAFE_STAT(FILENAME, &stat_buf);
66 check_owner(&stat_buf, uid, gid);
67 check_mode(&stat_buf, NEW_PERMS & ~(S_ISUID | S_ISGID));
68 }
69
setup(void)70 static void setup(void)
71 {
72 int fd;
73
74 ltpuser = SAFE_GETPWNAM("nobody");
75 SAFE_SETEGID(ltpuser->pw_gid);
76 SAFE_SETEUID(ltpuser->pw_uid);
77
78 fd = SAFE_OPEN(FILENAME, O_RDWR | O_CREAT, FILE_MODE);
79 SAFE_CLOSE(fd);
80 }
81
cleanup(void)82 static void cleanup(void)
83 {
84 SAFE_SETEGID(0);
85 SAFE_SETEUID(0);
86 }
87
88 static struct tst_test test = {
89 .needs_root = 1,
90 .needs_tmpdir = 1,
91 .setup = setup,
92 .cleanup = cleanup,
93 .test_all = run,
94 };
95