/*-
* 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.
*/
/*
* There are three cases in which the file system will clear the setuid or
* setgid bits on a file when running unprivileged:
*
* - When the file is chown()'d and either of the uid or the gid is changed.
* (currently, only changing the file gid applies, as privilege is required
* to change the uid).
*
* - The file is written to successfully.
*
* - An extended attribute of the file is written to successfully.
*
* In each case, check that the flags are cleared if unprivileged, and that
* they aren't cleared if privileged.
*
* We can't use expect() as we're looking for side-effects rather than
* success/failure of the system call.
*/
#include <sys/types.h>
#include <sys/extattr.h>
#include <sys/stat.h>
#include <err.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "main.h"
static char fpath[1024];
static int fpath_initialized;
/*
* If running as root, check that SUID is still set; otherwise, check that it
* is not.
*/
static void
confirm_sugid(char *test_case, int asroot, int injail)
{
struct stat sb;
if (stat(fpath, &sb) < 0) {
warn("%s stat(%s)", test_case, fpath);
return;
}
if (asroot) {
if (!(sb.st_mode & S_ISUID))
warnx("%s(root, %s): !SUID", test_case, injail ?
"jail" : "!jail");
} else {
if (sb.st_mode & S_ISUID)
warnx("%s(!root, %s): SUID", test_case, injail ?
"jail" : "!jail");
}
}
int
priv_vfs_clearsugid_setup(int asroot, int injail, struct test *test)
{
setup_file("priv_vfs_clearsugid_setup: fpath", fpath, UID_OWNER,
GID_OTHER, 0600 | S_ISUID);
fpath_initialized = 1;
return (0);
}
void
priv_vfs_clearsugid_chgrp(int asroot, int injail, struct test *test)
{
if (chown(fpath, -1, asroot ? GID_WHEEL : GID_OWNER) < 0)
err(-1, "priv_vfs_clearsugid_chgrp(%s, %s): chrgrp",
asroot ? "root" : "!root", injail ? "jail" : "!jail");
confirm_sugid("priv_vfs_clearsugid_chgrp", asroot, injail);
}
#define EA_NAMESPACE EXTATTR_NAMESPACE_USER
#define EA_NAME "clearsugid"
#define EA_DATA "test"
#define EA_SIZE (strlen(EA_DATA))
void
priv_vfs_clearsugid_extattr(int asroot, int injail, struct test *test)
{
if (extattr_set_file(fpath, EA_NAMESPACE, EA_NAME, EA_DATA, EA_SIZE)
< 0)
err(-1,
"priv_vfs_clearsugid_extattr(%s, %s): extattr_set_file",
asroot ? "root" : "!root", injail ? "jail" : "!jail");
confirm_sugid("priv_vfs_clearsugid_extattr", asroot, injail);
}
void
priv_vfs_clearsugid_write(int asroot, int injail, struct test *test)
{
int fd;
fd = open(fpath, O_RDWR);
if (fd < 0)
err(-1, "priv_vfs_clearsugid_write(%s, %s): open",
asroot ? "root" : "!root", injail ? "jail" : "!jail");
if (write(fd, EA_DATA, EA_SIZE) < 0)
err(-1, "priv_vfs_clearsugid_write(%s, %s): write",
asroot ? "root" : "!root", injail ? "jail" : "!jail");
(void)close(fd);
confirm_sugid("priv_vfs_clearsugid_write", asroot, injail);
}
void
priv_vfs_clearsugid_cleanup(int asroot, int injail, struct test *test)
{
if (fpath_initialized) {
(void)unlink(fpath);
fpath_initialized = 0;
}
}
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