1 /*- 2 * Copyright (c) 2006 nCircle Network Security, Inc. 3 * Copyright (c) 2007 Robert N. M. Watson 4 * All rights reserved. 5 * 6 * This software was developed by Robert N. M. Watson for the TrustedBSD 7 * Project under contract to nCircle Network Security, Inc. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY, 22 * INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 24 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 25 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 26 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 27 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33 /* 34 * There are three cases in which the file system will clear the setuid or 35 * setgid bits on a file when running unprivileged: 36 * 37 * - When the file is chown()'d and either of the uid or the gid is changed. 38 * (currently, only changing the file gid applies, as privilege is required 39 * to change the uid). 40 * 41 * - The file is written to successfully. 42 * 43 * - An extended attribute of the file is written to successfully. 44 * 45 * In each case, check that the flags are cleared if unprivileged, and that 46 * they aren't cleared if privileged. 47 * 48 * We can't use expect() as we're looking for side-effects rather than 49 * success/failure of the system call. 50 */ 51 52 #include <sys/types.h> 53 #include <sys/extattr.h> 54 #include <sys/stat.h> 55 56 #include <err.h> 57 #include <fcntl.h> 58 #include <stdlib.h> 59 #include <string.h> 60 #include <unistd.h> 61 62 #include "main.h" 63 64 static char fpath[1024]; 65 static int fpath_initialized; 66 67 /* 68 * If running as root, check that SUID is still set; otherwise, check that it 69 * is not. 70 */ 71 static void 72 confirm_sugid(char *test_case, int asroot, int injail) 73 { 74 struct stat sb; 75 76 if (stat(fpath, &sb) < 0) { 77 warn("%s stat(%s)", test_case, fpath); 78 return; 79 } 80 if (asroot) { 81 if (!(sb.st_mode & S_ISUID)) 82 warnx("%s(root, %s): !SUID", test_case, injail ? 83 "jail" : "!jail"); 84 } else { 85 if (sb.st_mode & S_ISUID) 86 warnx("%s(!root, %s): SUID", test_case, injail ? 87 "jail" : "!jail"); 88 } 89 } 90 91 int 92 priv_vfs_clearsugid_setup(int asroot, int injail, struct test *test) 93 { 94 95 setup_file("priv_vfs_clearsugid_setup: fpath", fpath, UID_OWNER, 96 GID_OTHER, 0600 | S_ISUID); 97 fpath_initialized = 1; 98 return (0); 99 } 100 101 void 102 priv_vfs_clearsugid_chgrp(int asroot, int injail, struct test *test) 103 { 104 105 if (chown(fpath, -1, asroot ? GID_WHEEL : GID_OWNER) < 0) 106 err(-1, "priv_vfs_clearsugid_chgrp(%s, %s): chrgrp", 107 asroot ? "root" : "!root", injail ? "jail" : "!jail"); 108 confirm_sugid("priv_vfs_clearsugid_chgrp", asroot, injail); 109 } 110 111 #define EA_NAMESPACE EXTATTR_NAMESPACE_USER 112 #define EA_NAME "clearsugid" 113 #define EA_DATA "test" 114 #define EA_SIZE (strlen(EA_DATA)) 115 116 void 117 priv_vfs_clearsugid_extattr(int asroot, int injail, struct test *test) 118 { 119 120 if (extattr_set_file(fpath, EA_NAMESPACE, EA_NAME, EA_DATA, EA_SIZE) 121 < 0) 122 err(-1, 123 "priv_vfs_clearsugid_extattr(%s, %s): extattr_set_file", 124 asroot ? "root" : "!root", injail ? "jail" : "!jail"); 125 confirm_sugid("priv_vfs_clearsugid_extattr", asroot, injail); 126 } 127 128 void 129 priv_vfs_clearsugid_write(int asroot, int injail, struct test *test) 130 { 131 int fd; 132 133 fd = open(fpath, O_RDWR); 134 if (fd < 0) 135 err(-1, "priv_vfs_clearsugid_write(%s, %s): open", 136 asroot ? "root" : "!root", injail ? "jail" : "!jail"); 137 if (write(fd, EA_DATA, EA_SIZE) < 0) 138 err(-1, "priv_vfs_clearsugid_write(%s, %s): write", 139 asroot ? "root" : "!root", injail ? "jail" : "!jail"); 140 (void)close(fd); 141 confirm_sugid("priv_vfs_clearsugid_write", asroot, injail); 142 } 143 144 void 145 priv_vfs_clearsugid_cleanup(int asroot, int injail, struct test *test) 146 { 147 148 if (fpath_initialized) { 149 (void)unlink(fpath); 150 fpath_initialized = 0; 151 } 152 } 153