/*- * Copyright (c) 2006 nCircle Network Security, Inc. * Copyright (c) 2007 Robert N. M. Watson * All rights reserved. * * This software was developed by Robert N. M. Watson for the TrustedBSD * Project under contract to nCircle Network Security, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY, * INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * Confirm that a generation number isn't returned by stat() when not running * with privilege. In order to differentiate between a generation of 0 and * a generation not being returned, we have to create a temporary file known * to have a non-0 generation. We try up to MAX_TRIES times, and then give * up, which is non-ideal, but better than not testing for a problem. */ #include <sys/stat.h> #include <err.h> #include <errno.h> #include <string.h> #include <unistd.h> #include "main.h" static char fpath[1024]; static int fpath_initialized; #define MAX_TRIES 100 int priv_vfs_generation_setup(int asroot, int injail, struct test *test) { struct stat sb; int i; /* * The kernel zeros the generation number field when an unprivileged * user stats a file. In order to distinguish the two cases, we * therefore require a file that we know has a non-zero generation * number. We try up to MAX_TRIES times and otherwise fail. */ for (i = 0; i < MAX_TRIES; i++) { setup_file("priv_vfs_generation_setup: fpath", fpath, UID_ROOT, GID_WHEEL, 0644); if (stat(fpath, &sb) < 0) { warn("priv_vfs_generation_setup: fstat(%s)", fpath); (void)unlink(fpath); return (-1); } if (sb.st_gen != 0) { fpath_initialized = 1; return (0); } } warnx("priv_vfs_generation_setup: unable to create gen file"); return (-1); } void priv_vfs_generation(int asroot, int injail, struct test *test) { struct stat sb; int error; error = stat(fpath, &sb); if (error < 0) warn("priv_vfs_generation(asroot, injail) stat"); if (sb.st_gen == 0) { error = -1; errno = EPERM; } else error = 0; if (asroot && injail) expect("priv_vfs_generation(asroot, injail)", error, -1, EPERM); if (asroot && !injail) expect("priv_vfs_generation(asroot, !injail)", error, 0, 0); if (!asroot && injail) expect("priv_vfs_generation(!asroot, injail)", error, -1, EPERM); if (!asroot && !injail) expect("priv_vfs_generation(!asroot, !injail)", error, -1, EPERM); } void priv_vfs_generation_cleanup(int asroot, int injail, struct test *test) { if (fpath_initialized) { (void)unlink(fpath); fpath_initialized = 0; } }