gems-kernel/source/THIRDPARTY/xnu/bsd/security/audit/audit_mac.c
2024-06-03 11:29:39 -05:00

252 lines
7.1 KiB
C

/*-
* Copyright (c) 1999-2020 Apple Inc.
* All rights reserved.
*
* @APPLE_BSD_LICENSE_HEADER_START@
*
* 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.
* 3. Neither the name of Apple Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS 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 APPLE OR ITS 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.
*
* @APPLE_BSD_LICENSE_HEADER_END@
*/
/*
* NOTICE: This file was modified by McAfee Research in 2004 to introduce
* support for mandatory and extensible security protections. This notice
* is included in support of clause 2.2 (b) of the Apple Public License,
* Version 2.0.
*/
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/kauth.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <bsm/audit.h>
#include <bsm/audit_internal.h>
#include <bsm/audit_kevents.h>
#include <security/audit/audit.h>
#include <security/audit/audit_private.h>
#include <mach/host_priv.h>
#include <mach/host_special_ports.h>
#include <mach/audit_triggers_server.h>
#include <kern/host.h>
#include <kern/zalloc.h>
#include <kern/sched_prim.h>
#if CONFIG_AUDIT
#if CONFIG_MACF
#include <bsm/audit_record.h>
#include <security/mac.h>
#include <security/mac_framework.h>
#include <security/mac_policy.h>
#define MAC_ARG_PREFIX "arg: "
#define MAC_ARG_PREFIX_LEN 5
ZONE_DEFINE(audit_mac_label_zone, "audit_mac_label_zone",
MAC_AUDIT_LABEL_LEN, ZC_NONE);
int
audit_mac_new(proc_t p, struct kaudit_record *ar)
{
struct mac mac;
/*
* Retrieve the MAC labels for the process.
*/
ar->k_ar.ar_cred_mac_labels = zalloc_flags(audit_mac_label_zone,
Z_WAITOK | Z_NOFAIL);
mac.m_buflen = MAC_AUDIT_LABEL_LEN;
mac.m_string = ar->k_ar.ar_cred_mac_labels;
if (mac_cred_label_externalize_audit(p, &mac)) {
zfree(audit_mac_label_zone, ar->k_ar.ar_cred_mac_labels);
return 1;
}
/*
* grab space for the reconds.
*/
ar->k_ar.ar_mac_records = (struct mac_audit_record_list_t *)
kalloc_type(struct mac_audit_record_list_t, Z_WAITOK);
if (ar->k_ar.ar_mac_records == NULL) {
zfree(audit_mac_label_zone, ar->k_ar.ar_cred_mac_labels);
return 1;
}
LIST_INIT(ar->k_ar.ar_mac_records);
ar->k_ar.ar_forced_by_mac = 0;
return 0;
}
void
audit_mac_free(struct kaudit_record *ar)
{
struct mac_audit_record *head, *next;
if (ar->k_ar.ar_vnode1_mac_labels != NULL) {
zfree(audit_mac_label_zone, ar->k_ar.ar_vnode1_mac_labels);
}
if (ar->k_ar.ar_vnode2_mac_labels != NULL) {
zfree(audit_mac_label_zone, ar->k_ar.ar_vnode2_mac_labels);
}
if (ar->k_ar.ar_cred_mac_labels != NULL) {
zfree(audit_mac_label_zone, ar->k_ar.ar_cred_mac_labels);
}
if (ar->k_ar.ar_arg_mac_string != NULL) {
kfree_data(ar->k_ar.ar_arg_mac_string,
MAC_MAX_LABEL_BUF_LEN + MAC_ARG_PREFIX_LEN);
}
/*
* Free the audit data from the MAC policies.
*/
head = LIST_FIRST(ar->k_ar.ar_mac_records);
while (head != NULL) {
next = LIST_NEXT(head, records);
zfree(mac_audit_data_zone, head->data);
kfree_type(struct mac_audit_record, head);
head = next;
}
kfree_type(struct mac_audit_record_list_t, ar->k_ar.ar_mac_records);
}
int
audit_mac_syscall_enter(unsigned short code, proc_t p, struct uthread *uthread,
kauth_cred_t my_cred, au_event_t event)
{
int error;
error = mac_audit_check_preselect(my_cred, code,
(void *)uthread->uu_arg);
if (error == MAC_AUDIT_YES) {
uthread->uu_ar = audit_new(event, p, uthread);
if (uthread->uu_ar) {
uthread->uu_ar->k_ar.ar_forced_by_mac = 1;
}
return 1;
} else if (error == MAC_AUDIT_NO) {
return 0;
} else if (error == MAC_AUDIT_DEFAULT) {
return 1;
}
return 0;
}
int
audit_mac_syscall_exit(unsigned short code, struct uthread *uthread, int error,
int retval)
{
int mac_error;
if (uthread->uu_ar == NULL) { /* syscall wasn't audited */
return 1;
}
/*
* Note, no other postselect mechanism exists. If
* mac_audit_check_postselect returns MAC_AUDIT_NO, the record will be
* suppressed. Other values at this point result in the audit record
* being committed. This suppression behavior will probably go away in
* the port to 10.3.4.
*/
mac_error = mac_audit_check_postselect(kauth_cred_get(), code,
(void *) uthread->uu_arg, error, retval,
uthread->uu_ar->k_ar.ar_forced_by_mac);
if (mac_error == MAC_AUDIT_YES) {
uthread->uu_ar->k_ar_commit |= AR_COMMIT_KERNEL;
} else if (mac_error == MAC_AUDIT_NO) {
audit_free(uthread->uu_ar);
return 1;
}
return 0;
}
/*
* This function is called by the MAC Framework to add audit data
* from a policy to the current audit record.
*/
int
audit_mac_data(int type, int len, u_char *data)
{
struct kaudit_record *cur;
struct mac_audit_record *record;
if (audit_enabled == 0) {
zfree(mac_audit_data_zone, data);
return ENOTSUP;
}
cur = currecord();
if (cur == NULL) {
zfree(mac_audit_data_zone, data);
return ENOTSUP;
}
/*
* XXX: Note that we silently drop the audit data if this
* allocation fails - this is consistent with the rest of the
* audit implementation.
*/
record = kalloc_type(struct mac_audit_record, Z_WAITOK | Z_NOFAIL);
record->type = type;
record->length = len;
record->data = data;
LIST_INSERT_HEAD(cur->k_ar.ar_mac_records, record, records);
return 0;
}
void
audit_arg_mac_string(struct kaudit_record *ar, char *string)
{
if (ar->k_ar.ar_arg_mac_string == NULL) {
ar->k_ar.ar_arg_mac_string = kalloc_data(MAC_MAX_LABEL_BUF_LEN + MAC_ARG_PREFIX_LEN, Z_WAITOK);
}
/*
* XXX This should be a rare event. If kalloc_data() returns NULL,
* the system is low on kernel virtual memory. To be
* consistent with the rest of audit, just return
* (may need to panic if required to for audit).
*/
if (ar->k_ar.ar_arg_mac_string == NULL) {
return;
}
strlcpy(ar->k_ar.ar_arg_mac_string, MAC_ARG_PREFIX,
MAC_ARG_PREFIX_LEN);
strlcpy(ar->k_ar.ar_arg_mac_string + MAC_ARG_PREFIX_LEN, string,
MAC_MAX_LABEL_BUF_LEN);
ARG_SET_VALID(ar, ARG_MAC_STRING);
}
#endif /* MAC */
#endif /* CONFIG_AUDIT */