/*
* Copyright (c) 2015 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <mach/exception_types.h>
#include <mach/mach_types.h>
#include <osfmk/kern/exception.h>
#include <osfmk/kern/task.h>
#include <sys/codesign.h>
#include <sys/param.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/proc_internal.h>
#include <sys/kauth.h>
#include <kern/task.h>
#include <kern/telemetry.h>
#include <security/mac_framework.h>
#include <security/mac_internal.h>
#include <security/mac_mach_internal.h>
#if CONFIG_CSR
#include <sys/csr.h>
// Panic on internal builds, just log otherwise.
#define MAC_MACH_UNEXPECTED(fmt...) \
if (csr_check(CSR_ALLOW_APPLE_INTERNAL) == 0) { panic(fmt); } else { printf(fmt); }
#else
#define MAC_MACH_UNEXPECTED(fmt...) printf(fmt)
#endif
static struct proc *
mac_task_get_proc(struct task *task)
{
if (task == current_task()) {
return proc_self();
}
/*
* Tasks don't really hold a reference on a proc unless the
* calling thread belongs to the task in question.
*/
int pid = task_pid(task);
struct proc *p = proc_find(pid);
if (p != NULL) {
if (proc_task(p) == task) {
return p;
}
proc_rele(p);
}
return NULL;
}
int
mac_task_check_expose_task(struct task *task, mach_task_flavor_t flavor)
{
int error;
assert(flavor <= TASK_FLAVOR_NAME);
struct proc *p = mac_task_get_proc(task);
if (p == NULL) {
return ESRCH;
}
struct proc_ident pident = proc_ident(p);
struct ucred *cred = kauth_cred_get();
proc_rele(p);
MAC_CHECK(proc_check_expose_task_with_flavor, cred, &pident, flavor);
return error;
}
int
mac_task_check_task_id_token_get_task(struct task *task, mach_task_flavor_t flavor)
{
int error;
struct proc *target_proc = NULL;
struct proc_ident *pidentp = NULL;
struct proc_ident pident;
assert(flavor <= TASK_FLAVOR_NAME);
if (!task_is_a_corpse(task)) {
/* only live task has proc */
target_proc = mac_task_get_proc(task);
if (target_proc == NULL) {
return ESRCH;
}
pident = proc_ident(target_proc);
pidentp = &pident;
proc_rele(target_proc);
}
/* pidentp is NULL for corpse task */
MAC_CHECK(proc_check_task_id_token_get_task,
current_cached_proc_cred(PROC_NULL), pidentp, flavor);
return error;
}
int
mac_task_check_get_movable_control_port(void)
{
int error;
MAC_CHECK(proc_check_get_movable_control_port,
current_cached_proc_cred(PROC_NULL));
return error;
}
int
mac_task_check_set_host_special_port(struct task *task, int id, struct ipc_port *port)
{
#pragma unused(task)
int error;
assert(task == current_task());
MAC_CHECK(proc_check_set_host_special_port,
current_cached_proc_cred(PROC_NULL), id, port);
return error;
}
int
mac_task_check_set_host_exception_port(struct task *task, unsigned int exception)
{
#pragma unused(task)
int error;
assert(task == current_task());
MAC_CHECK(proc_check_set_host_exception_port,
current_cached_proc_cred(PROC_NULL), exception);
return error;
}
int
mac_task_check_get_task_special_port(struct task *task, struct task *target, int which)
{
#pragma unused(task)
int error;
struct proc *target_proc = NULL;
struct proc_ident *pidentp = NULL;
struct proc_ident pident;
assert(task == current_task());
if (!task_is_a_corpse(target)) {
/* only live task has proc */
target_proc = mac_task_get_proc(target);
if (target_proc == NULL) {
return ESRCH;
}
pident = proc_ident(target_proc);
pidentp = &pident;
proc_rele(target_proc);
}
/* pidentp is NULL for corpse task */
MAC_CHECK(proc_check_get_task_special_port,
current_cached_proc_cred(PROC_NULL), pidentp, which);
return error;
}
int
mac_task_check_set_task_special_port(struct task *task, struct task *target, int which, struct ipc_port *port)
{
#pragma unused(task)
int error;
assert(task == current_task());
/* disallow setting task special ports for corpse */
if (task_is_a_corpse(target)) {
return EPERM;
}
struct proc *targetp = mac_task_get_proc(target);
if (targetp == NULL) {
return ESRCH;
}
struct proc_ident pident = proc_ident(targetp);
proc_rele(targetp);
MAC_CHECK(proc_check_set_task_special_port,
current_cached_proc_cred(PROC_NULL), &pident, which, port);
return error;
}
int
mac_task_check_set_task_exception_ports(struct task *task, struct task *target, unsigned int exception_mask, int new_behavior)
{
#pragma unused(task)
int error = 0;
int exception;
kauth_cred_t cred = current_cached_proc_cred(PROC_NULL);
assert(task == current_task());
/* disallow setting task exception ports for corpse */
if (task_is_a_corpse(target)) {
return EPERM;
}
struct proc *targetp = mac_task_get_proc(target);
if (targetp == NULL) {
return ESRCH;
}
struct proc_ident pident = proc_ident(targetp);
proc_rele(targetp);
for (exception = FIRST_EXCEPTION; exception < EXC_TYPES_COUNT; exception++) {
if (exception_mask & (1 << exception)) {
MAC_CHECK(proc_check_set_task_exception_port,
cred, &pident, exception, new_behavior);
if (error) {
break;
}
}
}
return error;
}
int
mac_task_check_set_thread_exception_ports(struct task *task, struct task *target, unsigned int exception_mask, int new_behavior)
{
#pragma unused(task)
int error = 0;
int exception;
kauth_cred_t cred = current_cached_proc_cred(PROC_NULL);
assert(task == current_task());
/* disallow setting thread exception ports for corpse */
if (task_is_a_corpse(target)) {
return EPERM;
}
struct proc *targetp = mac_task_get_proc(target);
if (targetp == NULL) {
return ESRCH;
}
struct proc_ident pident = proc_ident(targetp);
proc_rele(targetp);
for (exception = FIRST_EXCEPTION; exception < EXC_TYPES_COUNT; exception++) {
if (exception_mask & (1 << exception)) {
MAC_CHECK(proc_check_set_thread_exception_port,
cred, &pident, exception, new_behavior);
if (error) {
break;
}
}
}
return error;
}
int
mac_task_check_dyld_process_info_notify_register(void)
{
int error;
MAC_CHECK(proc_check_dyld_process_info_notify_register,
current_cached_proc_cred(PROC_NULL));
return error;
}
int
mac_task_check_set_host_exception_ports(struct task *task, unsigned int exception_mask)
{
#pragma unused(task)
int error = 0;
int exception;
kauth_cred_t cred = current_cached_proc_cred(PROC_NULL);
assert(task == current_task());
for (exception = FIRST_EXCEPTION; exception < EXC_TYPES_COUNT; exception++) {
if (exception_mask & (1 << exception)) {
MAC_CHECK(proc_check_set_host_exception_port,
cred, exception);
if (error) {
break;
}
}
}
return error;
}
void
mac_thread_userret(struct thread *td)
{
MAC_PERFORM(thread_userret, td);
}
void
mac_thread_telemetry(struct thread *t, int err, void *data, size_t length)
{
MAC_PERFORM(thread_telemetry, t, err, data, length);
}
void
mac_proc_notify_exec_complete(struct proc *proc)
{
thread_t thread = current_thread();
/*
* Since this MAC hook was designed to support upcalls, make sure the hook
* is called with kernel importance propagation enabled so any daemons
* can get any appropriate importance donations.
*/
thread_enable_send_importance(thread, TRUE);
MAC_PERFORM(proc_notify_exec_complete, proc);
thread_enable_send_importance(thread, FALSE);
}
/**** Exception Policy
*
* Note that the functions below do not fully follow the usual convention for mac policy functions
* in the kernel. Besides avoiding confusion in how the mac function names are mixed with the actual
* policy function names, we diverge because the exception policy is somewhat special:
* It is used in places where allocation and association must be separate, and its labels do not
* only belong to one type of object as usual, but to two (on exception actions and on tasks as
* crash labels).
*/
struct label *
mac_exc_label(struct exception_action *action)
{
return mac_label_verify(&action->label);
}
void
mac_exc_set_label(struct exception_action *action, struct label *label)
{
action->label = label;
}
// Label allocation and deallocation, may sleep.
struct label *
mac_exc_create_label(struct exception_action *action)
{
return mac_labelzone_alloc_for_owner(action ? &action->label : NULL, MAC_WAITOK, ^(struct label *label) {
// Policy initialization of the label, typically performs allocations as well.
// (Unless the policy's full data really fits into a pointer size.)
MAC_PERFORM(exc_action_label_init, label);
});
}
void
mac_exc_free_label(struct label *label)
{
MAC_PERFORM(exc_action_label_destroy, label);
mac_labelzone_free(label);
}
// Action label initialization and teardown, may sleep.
void
mac_exc_associate_action_label(struct exception_action *action, struct label *label)
{
mac_exc_set_label(action, label);
MAC_PERFORM(exc_action_label_associate, action, mac_exc_label(action));
}
void
mac_exc_free_action_label(struct exception_action *action)
{
mac_exc_free_label(mac_exc_label(action));
mac_exc_set_label(action, NULL);
}
// Action label update and inheritance, may NOT sleep and must be quick.
int
mac_exc_update_action_label(struct exception_action *action,
struct label *newlabel)
{
int error;
MAC_CHECK(exc_action_label_update, action, mac_exc_label(action), newlabel);
return error;
}
int
mac_exc_inherit_action_label(struct exception_action *parent,
struct exception_action *child)
{
return mac_exc_update_action_label(child, mac_exc_label(parent));
}
int
mac_exc_update_task_crash_label(struct task *task, struct label *label)
{
int error;
assert(task != kernel_task);
struct label *crash_label = get_task_crash_label(task);
MAC_CHECK(exc_action_label_update, NULL, crash_label, label);
return error;
}
// Process label creation, may sleep.
struct label *
mac_exc_create_label_for_proc(struct proc *proc)
{
struct label *label = mac_exc_create_label(NULL);
MAC_PERFORM(exc_action_label_populate, label, proc);
return label;
}
struct label *
mac_exc_create_label_for_current_proc(void)
{
return mac_exc_create_label_for_proc(current_proc());
}
// Exception handler policy checking, may sleep.
int
mac_exc_action_check_exception_send(struct task *victim_task, struct exception_action *action)
{
int error = 0;
struct proc *p = get_bsdtask_info(victim_task);
struct label *bsd_label = NULL;
struct label *label = NULL;
if (p != NULL) {
// Create a label from the still existing bsd process...
label = bsd_label = mac_exc_create_label_for_proc(p);
} else {
// ... otherwise use the crash label on the task.
label = get_task_crash_label(victim_task);
}
if (label == NULL) {
MAC_MACH_UNEXPECTED("mac_exc_action_check_exception_send: no exc_action label for process");
return EPERM;
}
MAC_CHECK(exc_action_check_exception_send, label, action, mac_exc_label(action));
if (bsd_label != NULL) {
mac_exc_free_label(bsd_label);
}
return error;
}
int
mac_schedule_telemetry(void)
{
return telemetry_macf_mark_curthread();
}