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/*-
* Copyright (c) 1999-2002, 2007 Robert N. M. Watson
* Copyright (c) 2001-2002 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research program.
*
* 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 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.
*
* $FreeBSD$
*/
/*
* Developed by the TrustedBSD Project.
*
* Prevent processes owned by a particular uid from seeing various transient
* kernel objects associated with other uids.
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <security/mac/mac_policy.h>
SYSCTL_DECL(_security_mac);
SYSCTL_NODE(_security_mac, OID_AUTO, seeotheruids, CTLFLAG_RW, 0,
"TrustedBSD mac_seeotheruids policy controls");
static int mac_seeotheruids_enabled = 1;
SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, enabled, CTLFLAG_RW,
&mac_seeotheruids_enabled, 0, "Enforce seeotheruids policy");
/*
* Exception: allow credentials to be aware of other credentials with the
* same primary gid.
*/
static int primarygroup_enabled = 0;
SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, primarygroup_enabled,
CTLFLAG_RW, &primarygroup_enabled, 0, "Make an exception for credentials "
"with the same real primary group id");
/*
* Exception: allow the root user to be aware of other credentials by virtue
* of privilege.
*/
static int suser_privileged = 1;
SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, suser_privileged,
CTLFLAG_RW, &suser_privileged, 0, "Make an exception for superuser");
/*
* Exception: allow processes with a specific gid to be exempt from the
* policy. One sysctl enables this functionality; the other sets the
* exempt gid.
*/
static int specificgid_enabled = 0;
SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, specificgid_enabled,
CTLFLAG_RW, &specificgid_enabled, 0, "Make an exception for credentials "
"with a specific gid as their real primary group id or group set");
static gid_t specificgid = 0;
SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, specificgid, CTLFLAG_RW,
&specificgid, 0, "Specific gid to be exempt from seeotheruids policy");
static int
mac_seeotheruids_check(struct ucred *cr1, struct ucred *cr2)
{
if (!mac_seeotheruids_enabled)
return (0);
if (primarygroup_enabled) {
if (cr1->cr_rgid == cr2->cr_rgid)
return (0);
}
if (specificgid_enabled) {
if (cr1->cr_rgid == specificgid ||
groupmember(specificgid, cr1))
return (0);
}
if (cr1->cr_ruid == cr2->cr_ruid)
return (0);
if (suser_privileged) {
if (priv_check_cred(cr1, PRIV_SEEOTHERUIDS, SUSER_ALLOWJAIL)
== 0)
return (0);
}
return (ESRCH);
}
static int
mac_seeotheruids_check_cred_visible(struct ucred *cr1, struct ucred *cr2)
{
return (mac_seeotheruids_check(cr1, cr2));
}
static int
mac_seeotheruids_check_proc_signal(struct ucred *cred, struct proc *p,
int signum)
{
return (mac_seeotheruids_check(cred, p->p_ucred));
}
static int
mac_seeotheruids_check_proc_sched(struct ucred *cred, struct proc *p)
{
return (mac_seeotheruids_check(cred, p->p_ucred));
}
static int
mac_seeotheruids_check_proc_debug(struct ucred *cred, struct proc *p)
{
return (mac_seeotheruids_check(cred, p->p_ucred));
}
static int
mac_seeotheruids_check_socket_visible(struct ucred *cred, struct socket *so,
struct label *solabel)
{
return (mac_seeotheruids_check(cred, so->so_cred));
}
static struct mac_policy_ops mac_seeotheruids_ops =
{
.mpo_check_cred_visible = mac_seeotheruids_check_cred_visible,
.mpo_check_proc_debug = mac_seeotheruids_check_proc_debug,
.mpo_check_proc_sched = mac_seeotheruids_check_proc_sched,
.mpo_check_proc_signal = mac_seeotheruids_check_proc_signal,
.mpo_check_socket_visible = mac_seeotheruids_check_socket_visible,
};
MAC_POLICY_SET(&mac_seeotheruids_ops, mac_seeotheruids,
"TrustedBSD MAC/seeotheruids", MPC_LOADTIME_FLAG_UNLOADOK, NULL);
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