platform_system_sepolicy/system_server.te

#
# System Server aka system_server spawned by zygote.
# Most of the framework services run in this process.
#
type system_server, domain, mlstrustedsubject;
permissive_or_unconfined(system_server)

# Define a type for tmpfs-backed ashmem regions.
tmpfs_domain(system_server)

# Dalvik Compiler JIT Mapping.
allow system_server self:process execmem;
allow system_server ashmem_device:chr_file execute;
allow system_server system_server_tmpfs:file execute;

# For art.
allow system_server dalvikcache_data_file:file execute;

# 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;
allow system_server zygote_tmpfs:file read;

# May kill zygote on crashes.
allow system_server zygote: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)
bluetooth_domain(system_server)

# These are the capabilities assigned by the zygote to the
# system server.
allow system_server self:capability {
    kill
    net_admin
    net_bind_service
    net_broadcast
    net_raw
    sys_boot
    sys_module
    sys_nice
    sys_resource
    sys_time
    sys_tty_config
};

allow system_server self:capability2 block_suspend;

# 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;

# Use netlink uevent sockets.
allow system_server self:netlink_kobject_uevent_socket create_socket_perms;

# Use generic netlink sockets.
allow system_server self:netlink_socket create_socket_perms;

# Kill apps.
allow system_server appdomain:process { sigkill signal };

# Set scheduling info for apps.
allow system_server appdomain:process { getsched setsched };
allow system_server mediaserver:process { getsched setsched };

# Read /proc/pid data for apps.
r_dir_file(system_server, appdomain)

# Write to /proc/pid/oom_adj_score for apps.
allow system_server appdomain:file write;

# Silently deny access to any /proc/pid files other than
# the ones allowed via allow rule.  Avoids filling the logs
# with noise from /proc/pid traversals by ActivityManager,
# CpuTracker, and possibly other system_server components.
dontaudit system_server domain:dir r_dir_perms;
dontaudit system_server domain:{ file lnk_file } r_file_perms;

# 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;

# Write to /proc/sysrq-trigger.
allow system_server proc_sysrq:file rw_file_perms;

# Read /sys/kernel/debug/wakeup_sources.
allow system_server debugfs:file r_file_perms;

# WifiWatchdog uses a packet_socket
allow system_server self:packet_socket create_socket_perms;

# 3rd party VPN clients require a tun_socket to be created
allow system_server self:tun_socket create_socket_perms;

# Notify init of death.
allow system_server init:process sigchld;

# Talk to init and various daemons via sockets.
unix_socket_connect(system_server, property, init)
unix_socket_connect(system_server, installd, installd)
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, zygote, zygote)
unix_socket_connect(system_server, gps, gpsd)
unix_socket_connect(system_server, racoon, racoon)
unix_socket_send(system_server, wpa, wpa)

# 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, binderservicedomain)
binder_call(system_server, appdomain)
binder_call(system_server, dumpstate)
binder_service(system_server)

# Read /proc/pid files for dumping stack traces of native processes.
r_dir_file(system_server, mediaserver)
r_dir_file(system_server, sdcardd)
r_dir_file(system_server, surfaceflinger)
r_dir_file(system_server, inputflinger)

# Use sockets received over binder from various services.
allow system_server mediaserver:tcp_socket rw_socket_perms;
allow system_server mediaserver: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;

# 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 graphics_device:dir search;
allow system_server graphics_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 urandom_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;

# tun device used for 3rd party vpn apps
allow system_server tun_device:chr_file rw_file_perms;

# Manage data files.
allow system_server data_file_type:dir create_dir_perms;
allow system_server data_file_type:notdevfile_class_set create_file_perms;

# Read /file_contexts and /data/security/file_contexts
security_access_policy(system_server)

# Relabel apk files.
relabelto_domain(system_server)
allow system_server { apk_tmp_file apk_private_tmp_file }:file { relabelfrom relabelto };
allow system_server { apk_data_file apk_private_data_file }: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 unlink };

# Relabel /data/anr.
allow system_server system_data_file:dir relabelfrom;
allow system_server anr_data_file:dir relabelto;

# Property Service write
allow system_server system_prop:property_service set;
allow system_server radio_prop:property_service set;
allow system_server debug_prop:property_service set;
allow system_server powerctl_prop:property_service set;

# ctl interface
allow system_server ctl_default_prop:property_service set;
allow system_server ctl_bugreport_prop:property_service set;

# 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;
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.
type_transition system_server system_data_file:sock_file system_ndebug_socket "ndebugsocket";
allow system_server system_ndebug_socket:sock_file create_file_perms;

# Specify any arguments to zygote.
allow system_server self:zygote { specifyids specifyrlimits specifyseinfo };

# Manage cache files.
allow system_server cache_file:dir { relabelfrom create_dir_perms };
allow system_server cache_file:file { relabelfrom create_file_perms };

# Run system programs, e.g. dexopt.
allow system_server system_file:file x_file_perms;

# LocationManager(e.g, GPS) needs to read and write
# to uart driver and ctrl proc entry
allow system_server gps_device:chr_file rw_file_perms;
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 { getattr read write };

# Allow abstract socket connection
allow system_server rild:unix_stream_socket connectto;

# BackupManagerService lets PMS create a data backup file
allow system_server cache_backup_file:file create_file_perms;
# Relabel /data/backup
allow system_server backup_data_file:dir { relabelto relabelfrom };
# Relabel /cache/.*\.{data|restore}
allow system_server cache_backup_file:file { relabelto relabelfrom };
# LocalTransport creates and relabels /cache/backup
allow system_server cache_backup_file:dir { relabelto relabelfrom create_dir_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;

# Access to wake locks
allow system_server sysfs_wake_lock:file rw_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;

# For SELinuxPolicyInstallReceiver
selinux_manage_policy(system_server)

# 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)

# 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;

###
### Neverallow rules
###
### system_server should NEVER do any of this

# Do not allow accessing SDcard files as unsafe ejection could
# cause the kernel to kill the system_server.
# neverallow system_server sdcard_type:file rw_file_perms;