171 lines
5.4 KiB
C
171 lines
5.4 KiB
C
/*-
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* Copyright (c) 1999-2002, 2007 Robert N. M. Watson
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* Copyright (c) 2001-2002 Networks Associates Technology, Inc.
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* All rights reserved.
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*
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* This software was developed by Robert Watson for the TrustedBSD Project.
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*
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* This software was developed for the FreeBSD Project in part by Network
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* Associates Laboratories, the Security Research Division of Network
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* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
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* as part of the DARPA CHATS research program.
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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 OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* Developed by the TrustedBSD Project.
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* Prevent processes owned by a particular uid from seeing various transient
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* kernel objects associated with other uids.
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*/
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/module.h>
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#include <sys/priv.h>
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#include <sys/proc.h>
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#include <sys/systm.h>
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#include <sys/socketvar.h>
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#include <sys/sysctl.h>
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#include <security/mac/mac_policy.h>
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SYSCTL_DECL(_security_mac);
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SYSCTL_NODE(_security_mac, OID_AUTO, seeotheruids, CTLFLAG_RW, 0,
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"TrustedBSD mac_seeotheruids policy controls");
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static int mac_seeotheruids_enabled = 1;
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SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, enabled, CTLFLAG_RW,
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&mac_seeotheruids_enabled, 0, "Enforce seeotheruids policy");
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/*
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* Exception: allow credentials to be aware of other credentials with the
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* same primary gid.
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*/
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static int primarygroup_enabled = 0;
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SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, primarygroup_enabled,
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CTLFLAG_RW, &primarygroup_enabled, 0, "Make an exception for credentials "
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"with the same real primary group id");
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/*
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* Exception: allow the root user to be aware of other credentials by virtue
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* of privilege.
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*/
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static int suser_privileged = 1;
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SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, suser_privileged,
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CTLFLAG_RW, &suser_privileged, 0, "Make an exception for superuser");
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/*
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* Exception: allow processes with a specific gid to be exempt from the
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* policy. One sysctl enables this functionality; the other sets the
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* exempt gid.
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*/
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static int specificgid_enabled = 0;
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SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, specificgid_enabled,
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CTLFLAG_RW, &specificgid_enabled, 0, "Make an exception for credentials "
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"with a specific gid as their real primary group id or group set");
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static gid_t specificgid = 0;
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SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, specificgid, CTLFLAG_RW,
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&specificgid, 0, "Specific gid to be exempt from seeotheruids policy");
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static int
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mac_seeotheruids_check(struct ucred *u1, struct ucred *u2)
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{
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if (!mac_seeotheruids_enabled)
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return (0);
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if (primarygroup_enabled) {
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if (u1->cr_rgid == u2->cr_rgid)
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return (0);
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}
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if (specificgid_enabled) {
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if (u1->cr_rgid == specificgid || groupmember(specificgid, u1))
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return (0);
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}
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if (u1->cr_ruid == u2->cr_ruid)
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return (0);
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if (suser_privileged) {
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if (priv_check_cred(u1, PRIV_SEEOTHERUIDS, SUSER_ALLOWJAIL)
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== 0)
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return (0);
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}
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return (ESRCH);
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}
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static int
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mac_seeotheruids_check_cred_visible(struct ucred *u1, struct ucred *u2)
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{
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return (mac_seeotheruids_check(u1, u2));
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}
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static int
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mac_seeotheruids_check_proc_signal(struct ucred *cred, struct proc *proc,
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int signum)
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{
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return (mac_seeotheruids_check(cred, proc->p_ucred));
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}
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static int
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mac_seeotheruids_check_proc_sched(struct ucred *cred, struct proc *proc)
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{
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return (mac_seeotheruids_check(cred, proc->p_ucred));
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}
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static int
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mac_seeotheruids_check_proc_debug(struct ucred *cred, struct proc *proc)
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{
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return (mac_seeotheruids_check(cred, proc->p_ucred));
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}
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static int
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mac_seeotheruids_check_socket_visible(struct ucred *cred, struct socket *socket,
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struct label *socketlabel)
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{
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return (mac_seeotheruids_check(cred, socket->so_cred));
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}
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static struct mac_policy_ops mac_seeotheruids_ops =
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{
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.mpo_check_cred_visible = mac_seeotheruids_check_cred_visible,
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.mpo_check_proc_debug = mac_seeotheruids_check_proc_debug,
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.mpo_check_proc_sched = mac_seeotheruids_check_proc_sched,
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.mpo_check_proc_signal = mac_seeotheruids_check_proc_signal,
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.mpo_check_socket_visible = mac_seeotheruids_check_socket_visible,
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};
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MAC_POLICY_SET(&mac_seeotheruids_ops, mac_seeotheruids,
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"TrustedBSD MAC/seeotheruids", MPC_LOADTIME_FLAG_UNLOADOK, NULL);
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