9fa5f6b4b9
implemented properly for a number of kernel subsystems. In general, they try to exercise the privilege first as the root user, then as a test user, in order to determine when privilege is being checked. Currently, these tests do not compare inside/outside jail, and probably should be enhanced to do that. Sponsored by: nCircle Network Security, Inc. Obtained from: TrustedBSD Project
141 lines
3.6 KiB
C
141 lines
3.6 KiB
C
/*-
|
|
* 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);
|
|
}
|