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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.
*
* $FreeBSD$
*/
/*
* Test that privilege is required to set the sgid bit on a file with a group
* that isn't in the process credential. The file uid owner is set to the
* uid being tested with, as we are not interested in testing privileges
* associated with file ownership.
*/
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include "main.h"
static const gid_t gidset_without[] = {GID_WHEEL};
static const gid_t gidset_with[] = {GID_WHEEL, GID_OWNER};
void
priv_vfs_setgid(void)
{
char fpath[1024];
int error, fd;
assert_root();
setup_file(fpath, UID_ROOT, GID_OWNER, 0644);
if (setgroups(1, gidset_without) < 0) {
warn("setgroups(1, {%d})", gidset_without[0]);
goto out;
}
fd = open(fpath, O_RDWR);
if (fd < 0) {
warn("open(%s, O_RDWR)", fpath);
goto out;
}
/*
* With privilege, set mode on file.
*/
if (fchmod(fd, 0600 | S_ISGID) < 0) {
warn("fchmod(%s, 0600 | S_ISGID) as root", fpath);
goto out;
}
/*
* Reset mode and chown file before dropping privilege.
*/
if (fchmod(fd, 0600) < 0) {
warn("fchmod(%s, 0600) as root", fpath);
goto out;
}
if (fchown(fd, UID_OWNER, GID_OWNER) < 0) {
warn("fchown(%s, %d, %d) as root", fpath, UID_OWNER,
GID_OTHER);
goto out;
}
/*
* Drop privilege.
*/
set_euid(UID_OWNER);
/*
* Without privilege, set mode on file.
*/
error = fchmod(fd, 0600 | S_ISGID);
if (error == 0) {
warnx("fchmod(%s, 0600 | S_ISGID) succeeded as !root",
fpath);
goto out;
}
if (errno != EPERM) {
warn("fchmod(%s, 0600 | S_ISGID) wrong errno %d as !root",
fpath, errno);
goto out;
}
/*
* Turn privilege back on so that we confirm privilege isn't required
* if we are a group member of the file's group.
*/
set_euid(UID_ROOT);
if (setgroups(2, gidset_with) < 0) {
warn("setgroups(2, {%d, %d})", gidset_with[0],
gidset_with[1]);
goto out;
}
if (seteuid(UID_OWNER) < 0) {
warn("seteuid(%d) pass 2", UID_OWNER);
goto out;
}
/*
* Without privilege, set mode on file (this time with right gid).
*/
if (fchmod(fd, 0600 | S_ISGID) < 0) {
warnx("fchmod(%s, 0600 | S_ISGID) pass 2 as !root", fpath);
sleep(10);
goto out;
}
out:
seteuid(UID_ROOT);
(void)unlink(fpath);
}
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