6356dba0b4
(1) Abstract interpreter vnode labeling in execve(2) and mac_execve(2)
so that the general exec code isn't aware of the details of
allocating, copying, and freeing labels, rather, simply passes in
a void pointer to start and stop functions that will be used by
the framework. This change will be MFC'd.
(2) Introduce a new flags field to the MAC_POLICY_SET(9) interface
allowing policies to declare which types of objects require label
allocation, initialization, and destruction, and define a set of
flags covering various supported object types (MPC_OBJECT_PROC,
MPC_OBJECT_VNODE, MPC_OBJECT_INPCB, ...). This change reduces the
overhead of compiling the MAC Framework into the kernel if policies
aren't loaded, or if policies require labels on only a small number
or even no object types. Each time a policy is loaded or unloaded,
we recalculate a mask of labeled object types across all policies
present in the system. Eliminate MAC_ALWAYS_LABEL_MBUF option as it
is no longer required.
MFC after: 1 week ((1) only)
Reviewed by: csjp
Obtained from: TrustedBSD Project
Sponsored by: Apple, Inc.
176 lines
5.4 KiB
C
176 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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* Copyright (c) 2006 SPARTA, 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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* This software was enhanced by SPARTA ISSO under SPAWAR contract
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* N66001-04-C-6019 ("SEFOS").
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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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*
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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 seeotheruids_enabled = 1;
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SYSCTL_INT(_security_mac_seeotheruids, OID_AUTO, enabled, CTLFLAG_RW,
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&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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seeotheruids_check(struct ucred *cr1, struct ucred *cr2)
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{
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if (!seeotheruids_enabled)
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return (0);
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if (primarygroup_enabled) {
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if (cr1->cr_rgid == cr2->cr_rgid)
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return (0);
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}
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if (specificgid_enabled) {
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if (cr1->cr_rgid == specificgid ||
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groupmember(specificgid, cr1))
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return (0);
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}
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if (cr1->cr_ruid == cr2->cr_ruid)
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return (0);
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if (suser_privileged) {
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if (priv_check_cred(cr1, PRIV_SEEOTHERUIDS, 0) == 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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seeotheruids_proc_check_debug(struct ucred *cred, struct proc *p)
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{
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return (seeotheruids_check(cred, p->p_ucred));
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}
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static int
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seeotheruids_proc_check_sched(struct ucred *cred, struct proc *p)
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{
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return (seeotheruids_check(cred, p->p_ucred));
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}
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static int
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seeotheruids_proc_check_signal(struct ucred *cred, struct proc *p,
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int signum)
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{
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return (seeotheruids_check(cred, p->p_ucred));
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}
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static int
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seeotheruids_cred_check_visible(struct ucred *cr1, struct ucred *cr2)
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{
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return (seeotheruids_check(cr1, cr2));
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}
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static int
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seeotheruids_socket_check_visible(struct ucred *cred, struct socket *so,
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struct label *solabel)
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{
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return (seeotheruids_check(cred, so->so_cred));
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}
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static struct mac_policy_ops seeotheruids_ops =
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{
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.mpo_proc_check_debug = seeotheruids_proc_check_debug,
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.mpo_proc_check_sched = seeotheruids_proc_check_sched,
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.mpo_proc_check_signal = seeotheruids_proc_check_signal,
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.mpo_cred_check_visible = seeotheruids_cred_check_visible,
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.mpo_socket_check_visible = seeotheruids_socket_check_visible,
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};
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MAC_POLICY_SET(&seeotheruids_ops, mac_seeotheruids,
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"TrustedBSD MAC/seeotheruids", MPC_LOADTIME_FLAG_UNLOADOK, NULL, 0);
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