This is xnu-12377.1.9. See this file in:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <darwintest.h>
#include <spawn.h>
#include <mach/mach.h>
#include <sys/sysctl.h>
#include <sys/csr.h>
#include <signal.h>
#include "excserver_protect_state.h"
#include "../osfmk/mach/port.h"
#include "../osfmk/kern/exc_guard.h"
#include "exc_helpers.h"
#include <sys/code_signing.h>
#include "cs_helpers.h"
#include <TargetConditionals.h>
#define MAX_ARGV 3
extern char **environ;
static mach_exception_data_type_t received_exception_code = 0;
static exception_type_t exception_taken = 0;
/*
* This test infrastructure is inspired from imm_pinned_control_port.c.
* It verifies no reply port security semantics are violated.
*
* 1. The rcv right of the port would be marked immovable.
*/
T_GLOBAL_META(
T_META_NAMESPACE("xnu.ipc"),
T_META_RADAR_COMPONENT_NAME("xnu"),
T_META_RADAR_COMPONENT_VERSION("IPC"),
T_META_TIMEOUT(10),
T_META_RUN_CONCURRENTLY(TRUE));
static bool
check_current_cs_flags(code_signing_config_t expected_cs_config)
{
code_signing_config_t cur_cs_config = 0;
size_t cs_config_size = sizeof(cur_cs_config);
sysctlbyname("security.codesigning.config", &cur_cs_config, &cs_config_size, NULL, 0);
return cur_cs_config & expected_cs_config;
}
static bool
unrestricted_debugging()
{
/* AMFI often disables security features if debugging is unrestricted */
bool unrestricted_debugging = check_current_cs_flags(CS_CONFIG_UNRESTRICTED_DEBUGGING);
if (unrestricted_debugging) {
T_LOG("UNRESTRICTED DEBUGGING");
}
return unrestricted_debugging;
}
static bool
sip_disabled()
{
#if XNU_TARGET_OS_OSX || XNU_TARGET_OS_BRIDGE
/* SIP can only be disabled on macOS */
bool sip_disabled = csr_check(CSR_ALLOW_UNRESTRICTED_FS) != 0;
if (sip_disabled) {
T_LOG("SIP DISABLED");
}
return sip_disabled;
#else
return false;
#endif
}
static bool
ipc_hardening_disabled()
{
#if TARGET_OS_OSX || TARGET_OS_BRIDGE
/*
* CS_CONFIG_GET_OUT_OF_MY_WAY (enabled via AMFI boot-args)
* disables IPC security features. This boot-arg previously
* caused a headache for developers on macos, who frequently use it for
* testing purposes, because all of their 3rd party apps will
* crash due to being treated as platform code. Unfortunately
* BATS runs with this boot-arg enabled very frequently.
*/
bool enforcement_disabled = check_current_cs_flags(CS_CONFIG_GET_OUT_OF_MY_WAY);
if (enforcement_disabled) {
T_LOG("IPC HARDENING ENFORCEMENT IS DISABLED");
} else {
T_LOG("IPC HARDENING ENABLED");
}
return enforcement_disabled;
#else /* TARGET_OS_OSX || TARGET_OS_BRIDGE */
/* mach hardening is only disabled by boot-args on macOS */
return false;
#endif
}
static bool
is_release_kernel()
{
int kernel_type = 0;
size_t kernel_type_size = sizeof(kernel_type);
int r;
r = sysctlbyname("kern.development", &kernel_type, &kernel_type_size, NULL, 0);
if (r < 0) {
T_WITH_ERRNO;
T_SKIP("could not find \"kern.development\" sysctl");
}
return kernel_type == 0;
}
static mach_port_t
alloc_exception_port(void)
{
kern_return_t kret;
mach_port_t exc_port = MACH_PORT_NULL;
mach_port_t task = mach_task_self();
kret = mach_port_allocate(task, MACH_PORT_RIGHT_RECEIVE, &exc_port);
T_QUIET; T_EXPECT_MACH_SUCCESS(kret, "mach_port_allocate exc_port");
kret = mach_port_insert_right(task, exc_port, exc_port, MACH_MSG_TYPE_MAKE_SEND);
T_QUIET; T_EXPECT_MACH_SUCCESS(kret, "mach_port_insert_right exc_port");
return exc_port;
}
kern_return_t
catch_mach_exception_raise_state(mach_port_t exception_port,
exception_type_t exception,
const mach_exception_data_t code,
mach_msg_type_number_t code_count,
int * flavor,
const thread_state_t old_state,
mach_msg_type_number_t old_state_count,
thread_state_t new_state,
mach_msg_type_number_t * new_state_count)
{
#pragma unused(exception_port, exception, code, code_count, flavor, old_state, old_state_count, new_state, new_state_count)
T_FAIL("Unsupported catch_mach_exception_raise_state");
return KERN_NOT_SUPPORTED;
}
kern_return_t
catch_mach_exception_raise_state_identity(mach_port_t exception_port,
mach_port_t thread,
mach_port_t task,
exception_type_t exception,
mach_exception_data_t code,
mach_msg_type_number_t code_count,
int * flavor,
thread_state_t old_state,
mach_msg_type_number_t old_state_count,
thread_state_t new_state,
mach_msg_type_number_t * new_state_count)
{
#pragma unused(exception_port, thread, task, exception, code, code_count, flavor, old_state, old_state_count, new_state, new_state_count)
T_FAIL("Unsupported catch_mach_exception_raise_state_identity");
return KERN_NOT_SUPPORTED;
}
kern_return_t
catch_mach_exception_raise_state_identity_protected(
__unused mach_port_t exception_port,
uint64_t thread_id,
mach_port_t task_id_token,
exception_type_t exception,
mach_exception_data_t codes,
mach_msg_type_number_t codeCnt,
__unused int * flavor,
__unused thread_state_t old_state,
__unused mach_msg_type_number_t old_state_count,
__unused thread_state_t new_state,
__unused mach_msg_type_number_t * new_state_count)
{
#pragma unused(exception_port, thread_id, task_id_token, exception, codes, codeCnt)
T_FAIL("Unsupported catch_mach_exception_raise_state_identity_protected");
return KERN_NOT_SUPPORTED;
}
kern_return_t
catch_mach_exception_raise_identity_protected(
__unused mach_port_t exception_port,
uint64_t thread_id,
mach_port_t task_id_token,
exception_type_t exception,
mach_exception_data_t codes,
mach_msg_type_number_t codeCnt)
{
#pragma unused(exception_port, thread_id, task_id_token)
T_ASSERT_GT_UINT(codeCnt, 1, "CodeCnt");
T_LOG("Caught %d codes", codeCnt);
T_LOG("Caught exception type: %d code[0]: 0x%llx code[1]:0x%llx", exception, codes[0], codes[1]);
exception_taken = exception;
if (exception == EXC_GUARD) {
received_exception_code = EXC_GUARD_DECODE_GUARD_FLAVOR((uint64_t)codes[0]);
} else {
T_FAIL("Unexpected exception");
}
return KERN_SUCCESS;
}
kern_return_t
catch_mach_exception_raise(mach_port_t exception_port,
mach_port_t thread,
mach_port_t task,
exception_type_t exception,
mach_exception_data_t code,
mach_msg_type_number_t code_count)
{
#pragma unused(exception_port, thread, task, exception, code, code_count)
T_FAIL("Unsupported catch_mach_exception_raise_state_identity");
return KERN_NOT_SUPPORTED;
}
static void *
exception_server_thread(void *arg)
{
kern_return_t kr;
mach_port_t exc_port = *(mach_port_t *)arg;
/* Handle exceptions on exc_port */
kr = mach_msg_server_once(mach_exc_server, 4096, exc_port, 0);
T_QUIET; T_EXPECT_MACH_SUCCESS(kr, "mach_msg_server_once");
return NULL;
}
static void
reply_port_defense(const bool thirdparty_hardened, int test_index, mach_exception_data_type_t expected_exception_code, bool triggers_exception)
{
/* reset exception code before running this test */
received_exception_code = 0;
int ret = 0;
uint32_t task_exc_guard = 0;
size_t te_size = sizeof(&task_exc_guard);
/* Test that the behavior is the same between these two */
char *test_prog_name = thirdparty_hardened ?
"./reply_port_defense_client_3P_hardened" : "./reply_port_defense_client";
char *child_args[MAX_ARGV];
pid_t client_pid = 0;
posix_spawnattr_t attrs;
pthread_t s_exc_thread;
mach_port_t exc_port;
T_LOG("Check if task_exc_guard exception has been enabled\n");
ret = sysctlbyname("kern.task_exc_guard_default", &task_exc_guard, &te_size, NULL, 0);
T_ASSERT_EQ(ret, 0, "sysctlbyname");
if (!(task_exc_guard & TASK_EXC_GUARD_MP_DELIVER)) {
T_SKIP("task_exc_guard exception is not enabled");
}
exc_port = alloc_exception_port();
T_QUIET; T_ASSERT_NE(exc_port, MACH_PORT_NULL, "Create a new exception port");
/* Create exception serving thread */
ret = pthread_create(&s_exc_thread, NULL, exception_server_thread, &exc_port);
T_QUIET; T_ASSERT_POSIX_SUCCESS(ret, "pthread_create exception_server_thread");
/* Initialize posix_spawn attributes */
posix_spawnattr_init(&attrs);
/*
* It is allowed for us to set an exception port because we are entitled test process.
* If you are using this code as an example for platform binaries,
* use `EXCEPTION_IDENTITY_PROTECTED` instead of `EXCEPTION_DEFAULT`
*/
int err = posix_spawnattr_setexceptionports_np(&attrs, EXC_MASK_GUARD, exc_port,
(exception_behavior_t) (EXCEPTION_IDENTITY_PROTECTED | MACH_EXCEPTION_CODES), 0);
T_QUIET; T_ASSERT_POSIX_SUCCESS(err, "posix_spawnattr_setflags");
child_args[0] = test_prog_name;
char test_num[10];
sprintf(test_num, "%d", test_index);
child_args[1] = test_num;
child_args[2] = NULL;
T_LOG("========== Spawning new child ==========");
err = posix_spawn(&client_pid, child_args[0], NULL, &attrs, &child_args[0], environ);
T_ASSERT_POSIX_SUCCESS(err, "posix_spawn reply_port_defense_client = %d", client_pid);
int child_status;
/* Wait for child and check for exception */
if (-1 == waitpid(-1, &child_status, 0)) {
T_FAIL("%s waitpid: child", strerror(errno));
}
if (WIFEXITED(child_status) && WEXITSTATUS(child_status)) {
T_FAIL("Child exited with status = 0x%x", child_status);
}
sleep(1);
kill(1, SIGKILL);
if (triggers_exception) {
ret = pthread_join(s_exc_thread, NULL);
T_QUIET; T_ASSERT_POSIX_SUCCESS(ret, "pthread_join");
}
mach_port_deallocate(mach_task_self(), exc_port);
T_LOG("Exception code: Received code = 0x%llx Expected code = 0x%llx", received_exception_code, expected_exception_code);
T_EXPECT_EQ(received_exception_code, expected_exception_code, "Exception code: Received == Expected");
}
T_DECL(reply_port_defense,
"Test reply port semantics violations",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false),
T_META_TAG_VM_PREFERRED,
T_META_ENABLED(!TARGET_OS_OSX && !TARGET_OS_BRIDGE)) {
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
bool triggers_exception = true;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_IMMOVABLE;
int test_num = 0;
int rp_defense_max_test_idx = 3;
/* Run the reply_port_defense tests 0, 1, 2 */
for (int i = test_num; i < rp_defense_max_test_idx; i++) {
reply_port_defense(true, i, expected_exception_code, triggers_exception);
reply_port_defense(false, i, expected_exception_code, triggers_exception);
}
reply_port_defense(true, 3, kGUARD_EXC_INVALID_RIGHT, triggers_exception);
reply_port_defense(false, 3, kGUARD_EXC_INVALID_RIGHT, triggers_exception);
}
T_DECL(test_unentitled_thread_set_exception_ports,
"thread_set_exception_ports should fail without an entitlement",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false)) {
int test_num = 5;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_EXCEPTION_BEHAVIOR_ENFORCE;
bool triggers_exception = true;
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
// reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_unentitled_thread_set_state,
"thread_set_state should fail without an entitlement",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false),
T_META_ENABLED(false /* rdar://133955889 */))
{
int test_num = 6;
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_THREAD_SET_STATE;
bool triggers_exception = true;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(unentitled_set_exception_ports_pass,
"set_exception_ports should succeed",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false)) {
int test_num = 7;
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_NONE;
bool triggers_exception = false;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(kobject_reply_port_defense,
"sending messages to kobjects without a proper reply port should crash",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_TAG_VM_PREFERRED,
T_META_CHECK_LEAKS(false),
T_META_ENABLED(!TARGET_OS_OSX && !TARGET_OS_BRIDGE)) { /* disable on macOS due to BATS boot-args */
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
int test_num = 9;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_KOBJECT_REPLY_PORT_SEMANTICS;
bool triggers_exception = true;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_alloc_weak_reply_port,
"1p is not allowed to create weak reply ports",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false)) {
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
int test_num = 10;
mach_exception_data_type_t expected_exception_code;
bool triggers_exception = true;
#if TARGET_OS_OSX || TARGET_OS_BRIDGE
expected_exception_code = kGUARD_EXC_PROVISIONAL_REPLY_PORT;
#else
expected_exception_code = kGUARD_EXC_INVALID_MPO_ENTITLEMENT;
#endif /* TARGET_OS_OSX || TARGET_OS_BRIDGE */
/* rdar://136996362 (iOS+ telemetry for restricting 1P usage of provisional reply port) */
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_move_service_port,
"service ports are immovable",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false)) {
int test_num = 11;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_SERVICE_PORT_VIOLATION_FATAL;
bool triggers_exception = true;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_notification_policy,
"registering notifications on an mktimer crashes",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false),
T_META_TAG_VM_PREFERRED,
T_META_ENABLED(!TARGET_OS_OSX && !TARGET_OS_BRIDGE)) { /* disable on macOS due to BATS boot-args */
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_INVALID_NOTIFICATION_REQ;
bool triggers_exception = true;
int test_num = 12;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
test_num = 13;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
test_num = 14;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_reply_port_extract_right_disallowed,
"mach_port_extract_right disallowed on reply port",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false)) {
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
int test_num = 15;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_INVALID_RIGHT;
bool triggers_exception = true;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_mach_task_self_send_movability,
"mach_task_self is immovable unless you have called ",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false)) {
if (ipc_hardening_disabled()) {
T_SKIP("hardening disabled due to boot-args");
}
int test_num = 16;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_IMMOVABLE;
bool triggers_exception = true;
if (sip_disabled() || unrestricted_debugging()) {
/*
* see `proc_check_get_movable_control_port`:
* enforcement is always controlled by entitlements and
* unrestricted debugging boot-arg
* or if SIP is disabled
*/
expected_exception_code = 0;
triggers_exception = false;
}
/*
* it should fail on reply_port_defense_client_3P_hardened because it doesn't
* have com.apple.security.get-movable-control-port
*/
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
test_num = 17; /* These tests crash the same way */
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
/*
* it should succeed on reply_port_defense_client because it
* has com.apple.security.get-movable-control-port
*/
test_num = 16;
expected_exception_code = 0;
triggers_exception = false;
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
test_num = 17;
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_send_immovability,
"ensure that send immovability is set on ports, even if they are not copied out",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false)) {
/* attempt to move ports created by mach port construct */
/* test_move_newly_constructed_port_immovable_send */
int test_num = 18;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_IMMOVABLE;
bool triggers_exception = true;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
/* test_move_special_reply_port */
test_num = 19;
expected_exception_code = kGUARD_EXC_IMMOVABLE;
triggers_exception = true;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_reply_port_header_disposition,
"Ensure only make_send_once is allowed for reply port",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false),
T_META_ENABLED(!TARGET_OS_OSX && !TARGET_OS_BRIDGE)) {
#if TARGET_OS_OSX || TARGET_OS_BRIDGE
T_SKIP("disabled on macos");
#endif
int test_num = 20;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_SEND_INVALID_REPLY;
bool triggers_exception = true;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}
T_DECL(test_service_port_as_exception_port,
"Ensure both service and weak service port can be used as exception port",
T_META_IGNORECRASHES(".*reply_port_defense_client.*"),
T_META_CHECK_LEAKS(false)) {
int test_num = 21;
mach_exception_data_type_t expected_exception_code = kGUARD_EXC_NONE;
bool triggers_exception = false;
reply_port_defense(true, test_num, expected_exception_code, triggers_exception);
reply_port_defense(false, test_num, expected_exception_code, triggers_exception);
}