91061084d1
All checking routines walk a linked list of all modules in order to determine if given hook is installed. This became a significant problem after mac_ntpd started being loaded by default. Implement a way perform checks for select hooks by testing a boolean. Use it for priv_check and priv_grant, which are constantly called from priv_check. The real fix would use hotpatching, but the above provides a way to know when to do it.
96 lines
3.2 KiB
C
96 lines
3.2 KiB
C
/*-
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* Copyright (c) 2006 nCircle Network Security, Inc.
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* Copyright (c) 2009 Robert N. M. Watson
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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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* This software was developed at the University of Cambridge Computer
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* Laboratory with support from a grant from Google, 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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/*
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* MAC checks for system privileges.
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*/
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#include "sys/cdefs.h"
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__FBSDID("$FreeBSD$");
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#include "opt_mac.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/priv.h>
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#include <sys/sdt.h>
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#include <sys/module.h>
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#include <security/mac/mac_framework.h>
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#include <security/mac/mac_internal.h>
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#include <security/mac/mac_policy.h>
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/*
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* The MAC Framework interacts with kernel privilege checks in two ways: it
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* may restrict the granting of privilege to a subject, and it may grant
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* additional privileges to the subject. Policies may implement none, one,
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* or both of these entry points. Restriction of privilege by any policy
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* always overrides granting of privilege by any policy or other privilege
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* mechanism. See kern_priv.c:priv_check_cred() for details of the
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* composition.
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*/
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MAC_CHECK_PROBE_DEFINE2(priv_check, "struct ucred *", "int");
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/*
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* Restrict access to a privilege for a credential. Return failure if any
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* policy denies access.
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*/
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int
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mac_priv_check_impl(struct ucred *cred, int priv)
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{
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int error;
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MAC_POLICY_CHECK_NOSLEEP(priv_check, cred, priv);
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MAC_CHECK_PROBE2(priv_check, error, cred, priv);
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return (error);
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}
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MAC_GRANT_PROBE_DEFINE2(priv_grant, "struct ucred *", "int");
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/*
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* Grant access to a privilege for a credential. Return success if any
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* policy grants access.
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*/
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int
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mac_priv_grant_impl(struct ucred *cred, int priv)
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{
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int error;
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MAC_POLICY_GRANT_NOSLEEP(priv_grant, cred, priv);
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MAC_GRANT_PROBE2(priv_grant, error, cred, priv);
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return (error);
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}
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