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/*-
* Copyright (c) 2006 nCircle Network Security, Inc.
* 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.
*
* $FreeBSD$
*/
/*
* Check that privilege is required to set the sticky bit on a file, but not
* a directory. Try with and without privilege.
*/
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <unistd.h>
#include "main.h"
static void
cleanup(const char *fpath, const char *dpath)
{
(void)seteuid(UID_ROOT);
(void)unlink(fpath);
if (dpath != NULL)
(void)rmdir(dpath);
}
void
priv_vfs_stickyfile(void)
{
char fpath[1024] = "/tmp/stickyfile.XXXXXXXXXXX";
char dpath[1024] = "/tmp/stickyfile.XXXXXXXXXXX", *dpathp;
int error, fd;
assert_root();
fd = mkstemp(fpath);
if (fd < 0)
err(-1, "mkstemp");
dpathp = mkdtemp(dpath);
if (dpathp == NULL) {
warn("mkdtemp");
goto out;
}
/*
* First, with privilege, set and clear the sticky bit on the file
* and directory.
*/
if (fchmod(fd, 0600 | S_ISTXT) < 0) {
warn("fchmod(%s, 0600 | S_ISTXT) on file as root", fpath);
goto out;
}
if (chmod(dpathp, 0700 | S_ISTXT) < 0) {
warn("chmod(%s, 0600 | S_ISTXT) on dir as root", dpath);
goto out;
}
/*
* Reset to remove sticky bit before changing credential.
*/
if (fchmod(fd, 0600) < 0) {
warn("fchmod(%s, 0600) on file as root", fpath);
goto out;
}
if (chmod(dpath, 0700) < 0) {
warn("chmod(%s, 0600) on dir as root", dpath);
goto out;
}
/*
* Chown the file and directory to target user -- we're checking for
* the specific right to set the sticky bit, not the general right to
* chmod().
*/
if (fchown(fd, UID_OTHER, -1) < 0) {
warn("fchown(%s, %d, -1)", fpath, UID_OTHER);
goto out;
}
if (chown(dpath, UID_OTHER, -1) < 0) {
warn("chown(%s, %d, -1)", fpath, UID_OTHER);
goto out;
}
/*
* Change credential and try again.
*/
set_euid(UID_OTHER);
error = fchmod(fd, 0600 | S_ISTXT);
if (error == 0) {
warnx("fchmod(%s, 0600 | S_ISTXT) succeeded on file as "
"!root", fpath);
goto out;
}
if (errno != EFTYPE) {
warn("fchmod(%s, 0600 | S_ISTXT) wrong errno %d as !root",
fpath, errno);
goto out;
}
if (chmod(dpathp, 0700 | S_ISTXT) < 0) {
warn("chmod(%s, 0600 | S_ISTXT) on dir as !root", dpath);
goto out;
}
out:
setuid(UID_ROOT);
cleanup(fpath, dpathp);
}
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