bd76450bdb
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
144 lines
3.7 KiB
C
144 lines
3.7 KiB
C
/*-
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* Copyright (c) 2006 nCircle Network Security, Inc.
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* All rights reserved.
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*
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* This software was developed by Robert N. M. Watson for the TrustedBSD
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* Project under contract to nCircle Network Security, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR, NCIRCLE NETWORK SECURITY,
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* INC., OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* Test that privilege is required to set the sgid bit on a file with a group
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* that isn't in the process credential. The file uid owner is set to the
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* uid being tested with, as we are not interested in testing privileges
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* associated with file ownership.
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*/
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#include <sys/stat.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include "main.h"
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static const gid_t gidset_without[] = {GID_WHEEL};
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static const gid_t gidset_with[] = {GID_WHEEL, GID_OWNER};
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void
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priv_vfs_setgid(void)
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{
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char fpath[1024];
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int error, fd;
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assert_root();
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setup_file(fpath, UID_ROOT, GID_OWNER, 0644);
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if (setgroups(1, gidset_without) < 0) {
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warn("setgroups(1, {%d})", gidset_without[0]);
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goto out;
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}
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fd = open(fpath, O_RDWR);
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if (fd < 0) {
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warn("open(%s, O_RDWR)", fpath);
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goto out;
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}
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/*
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* With privilege, set mode on file.
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*/
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if (fchmod(fd, 0600 | S_ISGID) < 0) {
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warn("fchmod(%s, 0600 | S_ISGID) as root", fpath);
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goto out;
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}
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/*
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* Reset mode and chown file before dropping privilege.
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*/
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if (fchmod(fd, 0600) < 0) {
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warn("fchmod(%s, 0600) as root", fpath);
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goto out;
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}
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if (fchown(fd, UID_OWNER, GID_OWNER) < 0) {
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warn("fchown(%s, %d, %d) as root", fpath, UID_OWNER,
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GID_OTHER);
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goto out;
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}
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/*
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* Drop privilege.
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*/
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set_euid(UID_OWNER);
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/*
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* Without privilege, set mode on file.
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*/
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error = fchmod(fd, 0600 | S_ISGID);
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if (error == 0) {
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warnx("fchmod(%s, 0600 | S_ISGID) succeeded as !root",
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fpath);
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goto out;
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}
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if (errno != EPERM) {
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warn("fchmod(%s, 0600 | S_ISGID) wrong errno %d as !root",
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fpath, errno);
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goto out;
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}
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/*
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* Turn privilege back on so that we confirm privilege isn't required
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* if we are a group member of the file's group.
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*/
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set_euid(UID_ROOT);
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if (setgroups(2, gidset_with) < 0) {
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warn("setgroups(2, {%d, %d})", gidset_with[0],
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gidset_with[1]);
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goto out;
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}
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if (seteuid(UID_OWNER) < 0) {
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warn("seteuid(%d) pass 2", UID_OWNER);
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goto out;
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}
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/*
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* Without privilege, set mode on file (this time with right gid).
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*/
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if (fchmod(fd, 0600 | S_ISGID) < 0) {
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warnx("fchmod(%s, 0600 | S_ISGID) pass 2 as !root", fpath);
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sleep(10);
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goto out;
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}
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out:
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seteuid(UID_ROOT);
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(void)unlink(fpath);
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}
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