2 * Copyright (c) 2011 Dag-Erling Smørgrav
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote
14 * products derived from this software without specific prior written
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * $OpenPAM: openpam_check_owner_perms.c 938 2017-04-30 21:34:42Z des $
36 #include <sys/types.h>
45 #include <security/pam_appl.h>
47 #include "openpam_impl.h"
52 * Verify that the file or directory referenced by the given descriptor is
53 * owned by either root or the arbitrator and that it is not writable by
58 openpam_check_desc_owner_perms(const char *name, int fd)
60 uid_t root, arbitrator;
65 arbitrator = geteuid();
66 if (fstat(fd, &sb) != 0) {
68 openpam_log(PAM_LOG_ERROR, "%s: %m", name);
72 if (!S_ISREG(sb.st_mode)) {
73 openpam_log(PAM_LOG_ERROR,
74 "%s: not a regular file", name);
78 if ((sb.st_uid != root && sb.st_uid != arbitrator) ||
79 (sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
80 openpam_log(PAM_LOG_ERROR,
81 "%s: insecure ownership or permissions", name);
91 * Verify that a file or directory and all components of the path leading
92 * up to it are owned by either root or the arbitrator and that they are
93 * not writable by group or other.
95 * Note that openpam_check_desc_owner_perms() should be used instead if
96 * possible to avoid a race between the ownership / permission check and
101 openpam_check_path_owner_perms(const char *path)
103 uid_t root, arbitrator;
104 char pathbuf[PATH_MAX];
106 int len, serrno, tip;
110 arbitrator = geteuid();
111 if (realpath(path, pathbuf) == NULL)
113 len = strlen(pathbuf);
115 if (stat(pathbuf, &sb) != 0) {
116 if (errno != ENOENT) {
118 openpam_log(PAM_LOG_ERROR, "%s: %m", pathbuf);
123 if (tip && !S_ISREG(sb.st_mode)) {
124 openpam_log(PAM_LOG_ERROR,
125 "%s: not a regular file", pathbuf);
129 if ((sb.st_uid != root && sb.st_uid != arbitrator) ||
130 (sb.st_mode & (S_IWGRP|S_IWOTH)) != 0) {
131 openpam_log(PAM_LOG_ERROR,
132 "%s: insecure ownership or permissions", pathbuf);
136 while (--len > 0 && pathbuf[len] != '/')