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  • #
    # System Server aka system_server spawned by zygote.
    # Most of the framework services run in this process.
    #
    
    typeattribute system_server domain_deprecated;
    typeattribute system_server mlstrustedsubject;
    
    
    # Define a type for tmpfs-backed ashmem regions.
    tmpfs_domain(system_server)
    
    # Create a socket for connections from crash_dump.
    
    type_transition system_server system_data_file:sock_file system_ndebug_socket "ndebugsocket";
    
    
    allow system_server zygote_tmpfs:file read;
    
    # Create a socket for receiving info from wpa.
    type_transition system_server wifi_data_file:sock_file system_wpa_socket;
    type_transition system_server wpa_socket:sock_file system_wpa_socket;
    
    
    # For art.
    allow system_server dalvikcache_data_file:dir r_dir_perms;
    allow system_server dalvikcache_data_file:file { r_file_perms execute };
    
    # Enable system server to check the foreign dex usage markers.
    # We need search on top level directories so that we can get to the files
    allow system_server user_profile_data_file:dir search;
    allow system_server user_profile_data_file:file getattr;
    allow system_server user_profile_foreign_dex_data_file:dir { add_name open read write search remove_name };
    allow system_server user_profile_foreign_dex_data_file:file { getattr rename unlink };
    
    # /data/resource-cache
    allow system_server resourcecache_data_file:file r_file_perms;
    allow system_server resourcecache_data_file:dir r_dir_perms;
    
    # ptrace to processes in the same domain for debugging crashes.
    allow system_server self:process ptrace;
    
    # Child of the zygote.
    allow system_server zygote:fd use;
    allow system_server zygote:process sigchld;
    
    # May kill zygote on crashes.
    allow system_server zygote:process sigkill;
    allow system_server crash_dump:process sigkill;
    
    # Read /system/bin/app_process.
    allow system_server zygote_exec:file r_file_perms;
    
    # Needed to close the zygote socket, which involves getopt / getattr
    allow system_server zygote:unix_stream_socket { getopt getattr };
    
    # system server gets network and bluetooth permissions.
    net_domain(system_server)
    # in addition to ioctls whitelisted for all domains, also allow system_server
    # to use privileged ioctls commands. Needed to set up VPNs.
    allowxperm system_server self:udp_socket ioctl priv_sock_ioctls;
    bluetooth_domain(system_server)
    
    # These are the capabilities assigned by the zygote to the
    # system server.
    allow system_server self:capability {
        ipc_lock
        kill
        net_admin
        net_bind_service
        net_broadcast
        net_raw
        sys_boot
        sys_nice
        sys_resource
        sys_time
        sys_tty_config
    };
    
    wakelock_use(system_server)
    
    # Triggered by /proc/pid accesses, not allowed.
    dontaudit system_server self:capability sys_ptrace;
    
    # Trigger module auto-load.
    allow system_server kernel:system module_request;
    
    # Allow alarmtimers to be set
    allow system_server self:capability2 wake_alarm;
    
    # Use netlink uevent sockets.
    allow system_server self:netlink_kobject_uevent_socket create_socket_perms_no_ioctl;
    
    # Use generic netlink sockets.
    allow system_server self:netlink_socket create_socket_perms_no_ioctl;
    allow system_server self:netlink_generic_socket create_socket_perms_no_ioctl;
    
    # Use generic "sockets" where the address family is not known
    # to the kernel. The ioctl permission is specifically omitted here, but may
    # be added to device specific policy along with the ioctl commands to be
    # whitelisted.
    allow system_server self:socket create_socket_perms_no_ioctl;
    
    # Set and get routes directly via netlink.
    allow system_server self:netlink_route_socket nlmsg_write;
    
    # Kill apps.
    allow system_server appdomain:process { sigkill signal };
    
    # Set scheduling info for apps.
    allow system_server appdomain:process { getsched setsched };
    allow system_server audioserver:process { getsched setsched };
    allow system_server hal_audio:process { getsched setsched };
    allow system_server cameraserver:process { getsched setsched };
    
    allow system_server hal_camera:process { getsched setsched };
    
    allow system_server mediaserver:process { getsched setsched };
    allow system_server bootanim:process { getsched setsched };
    
    # Read /proc/pid data for all domains. This is used by ProcessCpuTracker
    # within system_server to keep track of memory and CPU usage for
    # all processes on the device. In addition, /proc/pid files access is needed
    # for dumping stack traces of native processes.
    r_dir_file(system_server, domain)
    
    # Read/Write to /proc/net/xt_qtaguid/ctrl and and /dev/xt_qtaguid.
    allow system_server qtaguid_proc:file rw_file_perms;
    allow system_server qtaguid_device:chr_file rw_file_perms;
    
    # Read /proc/uid_cputime/show_uid_stat.
    allow system_server proc_uid_cputime_showstat:file r_file_perms;
    
    # Write /proc/uid_cputime/remove_uid_range.
    allow system_server proc_uid_cputime_removeuid:file { w_file_perms getattr };
    
    # Write /proc/uid_procstat/set.
    allow system_server proc_uid_procstat_set:file { w_file_perms getattr };
    
    # Write to /proc/sysrq-trigger.
    allow system_server proc_sysrq:file rw_file_perms;
    
    # Read /proc/stat for CPU usage statistics
    allow system_server proc_stat:file r_file_perms;
    
    # Read /sys/kernel/debug/wakeup_sources.
    allow system_server debugfs:file r_file_perms;
    
    # The DhcpClient and WifiWatchdog use packet_sockets
    allow system_server self:packet_socket create_socket_perms_no_ioctl;
    
    # NetworkDiagnostics requires explicit bind() calls to ping sockets. These aren't actually the same
    # as raw sockets, but the kernel doesn't yet distinguish between the two.
    allow system_server node:rawip_socket node_bind;
    
    # 3rd party VPN clients require a tun_socket to be created
    allow system_server self:tun_socket create_socket_perms_no_ioctl;
    
    # Talk to init and various daemons via sockets.
    unix_socket_connect(system_server, lmkd, lmkd)
    unix_socket_connect(system_server, mtpd, mtp)
    unix_socket_connect(system_server, netd, netd)
    unix_socket_connect(system_server, vold, vold)
    unix_socket_connect(system_server, webview_zygote, webview_zygote)
    unix_socket_connect(system_server, zygote, zygote)
    unix_socket_connect(system_server, racoon, racoon)
    unix_socket_send(system_server, wpa, wpa)
    unix_socket_connect(system_server, uncrypt, uncrypt)
    
    # Communicate over a socket created by surfaceflinger.
    allow system_server surfaceflinger:unix_stream_socket { read write setopt };
    
    # Perform Binder IPC.
    binder_use(system_server)
    binder_call(system_server, appdomain)
    binder_call(system_server, binderservicedomain)
    binder_call(system_server, dumpstate)
    binder_call(system_server, fingerprintd)
    binder_call(system_server, gatekeeperd)
    binder_call(system_server, installd)
    
    binder_call(system_server, incidentd)
    
    binder_call(system_server, netd)
    binder_call(system_server, wificond)
    binder_service(system_server)
    
    # Perform HwBinder IPC.
    hwbinder_use(system_server)
    
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    hwallocator_use(system_server)
    
    binder_call(system_server, hal_boot)
    binder_call(system_server, hal_contexthub)
    
    hal_client_domain(system_server, hal_fingerprint)
    
    binder_call(system_server, hal_gnss);
    binder_call(system_server, hal_ir)
    binder_call(system_server, hal_light)
    binder_call(system_server, hal_memtrack)
    binder_call(system_server, hal_power)
    binder_call(system_server, hal_sensors)
    binder_call(system_server, hal_thermal)
    binder_call(system_server, hal_usb)
    binder_call(system_server, hal_vibrator)
    binder_call(system_server, hal_vr)
    binder_call(system_server, hal_wifi)
    binder_call(system_server, wpa)
    
    # Talk to tombstoned to get ANR traces.
    unix_socket_connect(system_server, tombstoned_intercept, tombstoned)
    
    # Send signals to trigger ANR traces.
    # This is derived from the list that system server defines as interesting native processes
    # to dump during ANRs or watchdog aborts, defined in NATIVE_STACKS_OF_INTEREST in
    # frameworks/base/services/core/java/com/android/server/Watchdog.java.
    allow system_server {
      audioserver
      cameraserver
      drmserver
      inputflinger
      mediacodec
      mediadrmserver
      mediaextractor
      mediaserver
      mediametrics
      sdcardd
      surfaceflinger
    }:process { signal };
    
    # Use sockets received over binder from various services.
    allow system_server audioserver:tcp_socket rw_socket_perms;
    allow system_server audioserver:udp_socket rw_socket_perms;
    allow system_server mediaserver:tcp_socket rw_socket_perms;
    allow system_server mediaserver:udp_socket rw_socket_perms;
    
    # Use sockets received over binder from various services.
    allow system_server mediadrmserver:tcp_socket rw_socket_perms;
    allow system_server mediadrmserver:udp_socket rw_socket_perms;
    
    # Check SELinux permissions.
    selinux_check_access(system_server)
    
    # XXX Label sysfs files with a specific type?
    allow system_server sysfs:file rw_file_perms;
    allow system_server sysfs_nfc_power_writable:file rw_file_perms;
    allow system_server sysfs_devices_system_cpu:file w_file_perms;
    allow system_server sysfs_mac_address:file r_file_perms;
    allow system_server sysfs_thermal:dir search;
    allow system_server sysfs_thermal:file r_file_perms;
    
    # TODO: Remove when HALs are forced into separate processes
    allow system_server sysfs_vibrator:file { write append };
    
    # TODO: added to match above sysfs rule. Remove me?
    allow system_server sysfs_usb:file w_file_perms;
    
    # Access devices.
    allow system_server device:dir r_dir_perms;
    allow system_server mdns_socket:sock_file rw_file_perms;
    allow system_server alarm_device:chr_file rw_file_perms;
    allow system_server gpu_device:chr_file rw_file_perms;
    allow system_server iio_device:chr_file rw_file_perms;
    allow system_server input_device:dir r_dir_perms;
    allow system_server input_device:chr_file rw_file_perms;
    allow system_server radio_device:chr_file r_file_perms;
    allow system_server tty_device:chr_file rw_file_perms;
    allow system_server usbaccessory_device:chr_file rw_file_perms;
    allow system_server video_device:dir r_dir_perms;
    allow system_server video_device:chr_file rw_file_perms;
    allow system_server adbd_socket:sock_file rw_file_perms;
    allow system_server rtc_device:chr_file rw_file_perms;
    allow system_server audio_device:dir r_dir_perms;
    
    # write access needed for MIDI
    allow system_server audio_device:chr_file rw_file_perms;
    
    # tun device used for 3rd party vpn apps
    allow system_server tun_device:chr_file rw_file_perms;
    
    # Manage system data files.
    allow system_server system_data_file:dir create_dir_perms;
    allow system_server system_data_file:notdevfile_class_set create_file_perms;
    allow system_server keychain_data_file:dir create_dir_perms;
    allow system_server keychain_data_file:file create_file_perms;
    allow system_server keychain_data_file:lnk_file create_file_perms;
    
    # Manage /data/app.
    allow system_server apk_data_file:dir create_dir_perms;
    allow system_server apk_data_file:{ file lnk_file } { create_file_perms link };
    allow system_server apk_tmp_file:dir create_dir_perms;
    allow system_server apk_tmp_file:file create_file_perms;
    
    # Manage /data/app-private.
    allow system_server apk_private_data_file:dir create_dir_perms;
    allow system_server apk_private_data_file:file create_file_perms;
    allow system_server apk_private_tmp_file:dir create_dir_perms;
    allow system_server apk_private_tmp_file:file create_file_perms;
    
    # Manage files within asec containers.
    allow system_server asec_apk_file:dir create_dir_perms;
    allow system_server asec_apk_file:file create_file_perms;
    allow system_server asec_public_file:file create_file_perms;
    
    # Manage /data/anr.
    allow system_server anr_data_file:dir create_dir_perms;
    allow system_server anr_data_file:file create_file_perms;
    
    
    # Read /data/misc/incidents - only read. The fd will be sent over binder,
    # with no DAC access to it, for dropbox to read.
    allow system_server incident_data_file:file read;
    
    
    # Manage /data/backup.
    allow system_server backup_data_file:dir create_dir_perms;
    allow system_server backup_data_file:file create_file_perms;
    
    # Write to /data/system/heapdump
    allow system_server heapdump_data_file:dir rw_dir_perms;
    allow system_server heapdump_data_file:file create_file_perms;
    
    # Manage /data/misc/adb.
    allow system_server adb_keys_file:dir create_dir_perms;
    allow system_server adb_keys_file:file create_file_perms;
    
    # Manage /data/misc/sms.
    # TODO:  Split into a separate type?
    allow system_server radio_data_file:dir create_dir_perms;
    allow system_server radio_data_file:file create_file_perms;
    
    # Manage /data/misc/systemkeys.
    allow system_server systemkeys_data_file:dir create_dir_perms;
    allow system_server systemkeys_data_file:file create_file_perms;
    
    # Access /data/tombstones.
    allow system_server tombstone_data_file:dir r_dir_perms;
    allow system_server tombstone_data_file:file r_file_perms;
    
    # Manage /data/misc/vpn.
    allow system_server vpn_data_file:dir create_dir_perms;
    allow system_server vpn_data_file:file create_file_perms;
    
    # Manage /data/misc/wifi.
    allow system_server wifi_data_file:dir create_dir_perms;
    allow system_server wifi_data_file:file create_file_perms;
    
    # Manage /data/misc/zoneinfo.
    allow system_server zoneinfo_data_file:dir create_dir_perms;
    allow system_server zoneinfo_data_file:file create_file_perms;
    
    # Walk /data/data subdirectories.
    # Types extracted from seapp_contexts type= fields.
    allow system_server { system_app_data_file bluetooth_data_file nfc_data_file radio_data_file shell_data_file app_data_file }:dir { getattr read search };
    # Also permit for unlabeled /data/data subdirectories and
    # for unlabeled asec containers on upgrades from 4.2.
    allow system_server unlabeled:dir r_dir_perms;
    # Read pkg.apk file before it has been relabeled by vold.
    allow system_server unlabeled:file r_file_perms;
    
    # Populate com.android.providers.settings/databases/settings.db.
    allow system_server system_app_data_file:dir create_dir_perms;
    allow system_server system_app_data_file:file create_file_perms;
    
    # Receive and use open app data files passed over binder IPC.
    # Types extracted from seapp_contexts type= fields.
    allow system_server { system_app_data_file bluetooth_data_file nfc_data_file radio_data_file shell_data_file app_data_file }:file { getattr read write append };
    
    # Access to /data/media for measuring disk usage.
    allow system_server media_rw_data_file:dir { search getattr open read };
    
    # Receive and use open /data/media files passed over binder IPC.
    # Also used for measuring disk usage.
    allow system_server media_rw_data_file:file { getattr read write append };
    
    # Relabel apk files.
    allow system_server { apk_tmp_file apk_private_tmp_file }:{ dir file } { relabelfrom relabelto };
    allow system_server { apk_data_file apk_private_data_file }:{ dir file } { relabelfrom relabelto };
    
    # Relabel wallpaper.
    allow system_server system_data_file:file relabelfrom;
    allow system_server wallpaper_file:file relabelto;
    allow system_server wallpaper_file:file { rw_file_perms rename unlink };
    
    # Backup of wallpaper imagery uses temporary hard links to avoid data churn
    allow system_server { system_data_file wallpaper_file }:file link;
    
    # ShortcutManager icons
    allow system_server system_data_file:dir relabelfrom;
    allow system_server shortcut_manager_icons:dir { create_dir_perms relabelto };
    allow system_server shortcut_manager_icons:file create_file_perms;
    
    # Manage ringtones.
    allow system_server ringtone_file:dir { create_dir_perms relabelto };
    allow system_server ringtone_file:file create_file_perms;
    
    # Relabel icon file.
    allow system_server icon_file:file relabelto;
    allow system_server icon_file:file { rw_file_perms unlink };
    
    # FingerprintService.java does a restorecon of the directory /data/system/users/[0-9]+/fpdata(/.*)?
    allow system_server system_data_file:dir relabelfrom;
    
    # Property Service write
    set_prop(system_server, system_prop)
    set_prop(system_server, safemode_prop)
    set_prop(system_server, dhcp_prop)
    set_prop(system_server, net_radio_prop)
    
    set_prop(system_server, net_dns_prop)
    
    set_prop(system_server, system_radio_prop)
    set_prop(system_server, debug_prop)
    set_prop(system_server, powerctl_prop)
    set_prop(system_server, fingerprint_prop)
    set_prop(system_server, device_logging_prop)
    set_prop(system_server, wifi_prop)
    set_prop(system_server, dumpstate_options_prop)
    set_prop(system_server, overlay_prop)
    userdebug_or_eng(`set_prop(system_server, wifi_log_prop)')
    
    # ctl interface
    set_prop(system_server, ctl_default_prop)
    set_prop(system_server, ctl_bugreport_prop)
    
    # cppreopt property
    set_prop(system_server, cppreopt_prop)
    
    # Collect metrics on boot time created by init
    get_prop(system_server, boottime_prop)
    
    # Read device's serial number from system properties
    get_prop(system_server, serialno_prop)
    
    # Read/write the property which keeps track of whether this is the first start of system_server
    set_prop(system_server, firstboot_prop)
    
    # Create a socket for receiving info from wpa.
    allow system_server wpa_socket:dir rw_dir_perms;
    allow system_server system_wpa_socket:sock_file create_file_perms;
    
    # Remove sockets created by wpa_supplicant
    allow system_server wpa_socket:sock_file unlink;
    
    # Create a socket for connections from debuggerd.
    allow system_server system_ndebug_socket:sock_file create_file_perms;
    
    # Manage cache files.
    allow system_server { cache_file cache_recovery_file }:dir { relabelfrom create_dir_perms };
    allow system_server { cache_file cache_recovery_file }:file { relabelfrom create_file_perms };
    allow system_server { cache_file cache_recovery_file }:fifo_file create_file_perms;
    
    allow system_server system_file:dir r_dir_perms;
    allow system_server system_file:lnk_file r_file_perms;
    
    # LocationManager(e.g, GPS) needs to read and write
    # to uart driver and ctrl proc entry
    allow system_server gps_control:file rw_file_perms;
    
    # Allow system_server to use app-created sockets and pipes.
    allow system_server appdomain:{ tcp_socket udp_socket } { getattr getopt setopt read write shutdown };
    allow system_server appdomain:{ fifo_file unix_stream_socket } { getattr read write };
    
    # Allow abstract socket connection
    allow system_server rild:unix_stream_socket connectto;
    
    # BackupManagerService needs to manipulate backup data files
    allow system_server cache_backup_file:dir rw_dir_perms;
    allow system_server cache_backup_file:file create_file_perms;
    # LocalTransport works inside /cache/backup
    allow system_server cache_private_backup_file:dir create_dir_perms;
    allow system_server cache_private_backup_file:file create_file_perms;
    
    # Allow system to talk to usb device
    allow system_server usb_device:chr_file rw_file_perms;
    allow system_server usb_device:dir r_dir_perms;
    
    # Allow system to talk to sensors
    allow system_server sensors_device:chr_file rw_file_perms;
    
    # Read from HW RNG (needed by EntropyMixer).
    allow system_server hw_random_device:chr_file r_file_perms;
    
    # Read and delete files under /dev/fscklogs.
    r_dir_file(system_server, fscklogs)
    allow system_server fscklogs:dir { write remove_name };
    allow system_server fscklogs:file unlink;
    
    # logd access, system_server inherit logd write socket
    # (urge is to deprecate this long term)
    allow system_server zygote:unix_dgram_socket write;
    
    # Read from log daemon.
    read_logd(system_server)
    read_runtime_log_tags(system_server)
    
    # Be consistent with DAC permissions. Allow system_server to write to
    # /sys/module/lowmemorykiller/parameters/adj
    # /sys/module/lowmemorykiller/parameters/minfree
    allow system_server sysfs_lowmemorykiller:file { getattr w_file_perms };
    
    # Read /sys/fs/pstore/console-ramoops
    # Don't worry about overly broad permissions for now, as there's
    # only one file in /sys/fs/pstore
    allow system_server pstorefs:dir r_dir_perms;
    allow system_server pstorefs:file r_file_perms;
    
    # /sys access
    allow system_server sysfs_zram:dir search;
    allow system_server sysfs_zram:file r_file_perms;
    
    add_service(system_server, system_server_service);
    allow system_server audioserver_service:service_manager find;
    allow system_server batteryproperties_service:service_manager find;
    allow system_server cameraserver_service:service_manager find;
    allow system_server drmserver_service:service_manager find;
    allow system_server dumpstate_service:service_manager find;
    allow system_server fingerprintd_service:service_manager find;
    allow system_server hal_fingerprint_service:service_manager find;
    allow system_server gatekeeper_service:service_manager find;
    
    allow system_server incident_service:service_manager find;
    
    allow system_server installd_service:service_manager find;
    allow system_server keystore_service:service_manager find;
    allow system_server mediaserver_service:service_manager find;
    allow system_server mediametrics_service:service_manager find;
    allow system_server mediaextractor_service:service_manager find;
    allow system_server mediacodec_service:service_manager find;
    allow system_server mediadrmserver_service:service_manager find;
    allow system_server netd_service:service_manager find;
    allow system_server nfc_service:service_manager find;
    allow system_server radio_service:service_manager find;
    allow system_server surfaceflinger_service:service_manager find;
    allow system_server wificond_service:service_manager find;
    
    allow system_server keystore:keystore_key {
    	get_state
    	get
    	insert
    	delete
    	exist
    	list
    	reset
    	password
    	lock
    	unlock
    	is_empty
    	sign
    	verify
    	grant
    	duplicate
    	clear_uid
    	add_auth
    	user_changed
    };
    
    # Allow system server to search and write to the persistent factory reset
    # protection partition. This block device does not get wiped in a factory reset.
    allow system_server block_device:dir search;
    allow system_server frp_block_device:blk_file rw_file_perms;
    
    # Clean up old cgroups
    allow system_server cgroup:dir { remove_name rmdir };
    
    # /oem access
    r_dir_file(system_server, oemfs)
    
    # Allow resolving per-user storage symlinks
    allow system_server { mnt_user_file storage_file }:dir { getattr search };
    allow system_server { mnt_user_file storage_file }:lnk_file { getattr read };
    
    # Allow statfs() on storage devices, which happens fast enough that
    # we shouldn't be killed during unsafe removal
    allow system_server sdcard_type:dir { getattr search };
    
    # Traverse into expanded storage
    allow system_server mnt_expand_file:dir r_dir_perms;
    
    # Allow system process to relabel the fingerprint directory after mkdir
    # and delete the directory and files when no longer needed
    allow system_server fingerprintd_data_file:dir { r_dir_perms remove_name rmdir relabelto write };
    allow system_server fingerprintd_data_file:file { getattr unlink };
    
    # Allow system process to read network MAC address
    allow system_server sysfs_mac_address:file r_file_perms;
    
    userdebug_or_eng(`
      # Allow system server to create and write method traces in /data/misc/trace.
      allow system_server method_trace_data_file:dir w_dir_perms;
      allow system_server method_trace_data_file:file { create w_file_perms };
    
      # Allow system server to read dmesg
      allow system_server kernel:system syslog_read;
    ')
    
    # For AppFuse.
    allow system_server vold:fd use;
    allow system_server fuse_device:chr_file { read write ioctl getattr };
    allow system_server app_fuse_file:dir rw_dir_perms;
    allow system_server app_fuse_file:file { read write open getattr append };
    
    # For configuring sdcardfs
    allow system_server configfs:dir { create_dir_perms };
    allow system_server configfs:file { getattr open unlink write };
    
    # Connect to adbd and use a socket transferred from it.
    # Used for e.g. jdwp.
    allow system_server adbd:unix_stream_socket connectto;
    allow system_server adbd:fd use;
    allow system_server adbd:unix_stream_socket { getattr getopt ioctl read write shutdown };
    
    # Allow invoking tools like "timeout"
    allow system_server toolbox_exec:file rx_file_perms;
    
    # Postinstall
    #
    # For OTA dexopt, allow calls coming from postinstall.
    binder_call(system_server, postinstall)
    
    allow system_server postinstall:fifo_file write;
    allow system_server update_engine:fd use;
    allow system_server update_engine:fifo_file write;
    
    # Access to /data/preloads
    allow system_server preloads_data_file:file { r_file_perms unlink };
    allow system_server preloads_data_file:dir { r_dir_perms write remove_name rmdir };
    
    r_dir_file(system_server, cgroup)
    allow system_server ion_device:chr_file r_file_perms;
    allow system_server hal_graphics_allocator:fd use;
    
    r_dir_file(system_server, proc)
    r_dir_file(system_server, proc_meminfo)
    r_dir_file(system_server, proc_net)
    r_dir_file(system_server, rootfs)
    r_dir_file(system_server, sysfs_type)
    
    # Allow system_server to make binder calls to hwservicemanager
    binder_call(system_server, hwservicemanager)
    
    ### Rules needed when Light HAL runs inside system_server process.
    ### These rules should eventually be granted only when needed.
    allow system_server sysfs_leds:lnk_file read;
    allow system_server sysfs_leds:file rw_file_perms;
    allow system_server sysfs_leds:dir r_dir_perms;
    ###
    
    userdebug_or_eng(`
      # Allow WifiService to start, stop, and read wifi-specific trace events.
      allow system_server debugfs_tracing_instances:dir search;
      allow system_server debugfs_wifi_tracing:file rw_file_perms;
    ')
    
    ###
    ### Neverallow rules
    ###
    ### system_server should NEVER do any of this
    
    # Do not allow opening files from external storage as unsafe ejection
    # could cause the kernel to kill the system_server.
    neverallow system_server sdcard_type:dir { open read write };
    neverallow system_server sdcard_type:file rw_file_perms;
    
    # system server should never be operating on zygote spawned app data
    # files directly. Rather, they should always be passed via a
    # file descriptor.
    # Types extracted from seapp_contexts type= fields, excluding
    # those types that system_server needs to open directly.
    neverallow system_server { bluetooth_data_file nfc_data_file shell_data_file app_data_file }:file { open create unlink link };
    
    # Forking and execing is inherently dangerous and racy. See, for
    # example, https://www.linuxprogrammingblog.com/threads-and-fork-think-twice-before-using-them
    # Prevent the addition of new file execs to stop the problem from
    # getting worse. b/28035297
    neverallow system_server { file_type -toolbox_exec -logcat_exec }:file execute_no_trans;
    
    # Ensure that system_server doesn't perform any domain transitions other than
    # transitioning to the crash_dump domain when a crash occurs.
    neverallow system_server { domain -crash_dump }:process transition;
    neverallow system_server *:process dyntransition;
    
    # Only allow crash_dump to connect to system_ndebug_socket.
    neverallow { domain -init -system_server -crash_dump } system_ndebug_socket:sock_file { open write };
    
    # system_server should never be executing dex2oat. This is either
    # a bug (for example, bug 16317188), or represents an attempt by
    # system server to dynamically load a dex file, something we do not
    # want to allow.
    neverallow system_server dex2oat_exec:file no_x_file_perms;
    
    # system_server should never execute or load executable shared libraries
    # in /data except for /data/dalvik-cache files.
    neverallow system_server {
      data_file_type
      -dalvikcache_data_file #mapping with PROT_EXEC
    }:file no_x_file_perms;
    
    # The only block device system_server should be accessing is
    # the frp_block_device. This helps avoid a system_server to root
    # escalation by writing to raw block devices.
    neverallow system_server { dev_type -frp_block_device }:blk_file no_rw_file_perms;
    
    # system_server should never use JIT functionality
    neverallow system_server self:process execmem;
    neverallow system_server ashmem_device:chr_file execute;
    
    
    # TODO: deal with tmpfs_domain pub/priv split properly
    
    Nick Kralevich's avatar
    Nick Kralevich committed
    neverallow system_server system_server_tmpfs:file execute;
    
    
    # dexoptanalyzer is currently used only for secondary dex files which
    # system_server should never access.
    neverallow system_server dexoptanalyzer_exec:file no_x_file_perms;