platform_system_sepolicy/private/audioserver.te

# audioserver - audio services daemon
type audioserver_exec, exec_type, file_type, system_file_type;
typeattribute audioserver coredomain;

init_daemon_domain(audioserver)
tmpfs_domain(audioserver)

r_dir_file(audioserver, sdcard_type)
r_dir_file(audioserver, fuse)

binder_use(audioserver)
binder_call(audioserver, binderservicedomain)
binder_call(audioserver, appdomain)
binder_service(audioserver)

hal_client_domain(audioserver, hal_allocator)
# /system/lib64/hw for always-passthrough Allocator HAL ashmem / mapper .so
r_dir_file(audioserver, system_file)

hal_client_domain(audioserver, hal_audio)

userdebug_or_eng(`
  # used for TEE sink - pcm capture for debug.
  allow audioserver media_data_file:dir create_dir_perms;
  allow audioserver audioserver_data_file:dir create_dir_perms;
  allow audioserver audioserver_data_file:file create_file_perms;

  # ptrace to processes in the same domain for memory leak detection
  allow audioserver self:process ptrace;
')

add_service(audioserver, audioserver_service)
allow audioserver activity_service:service_manager find;
allow audioserver appops_service:service_manager find;
allow audioserver batterystats_service:service_manager find;
allow audioserver external_vibrator_service:service_manager find;
allow audioserver package_native_service:service_manager find;
allow audioserver permission_service:service_manager find;
allow audioserver permission_checker_service:service_manager find;
allow audioserver power_service:service_manager find;
allow audioserver scheduling_policy_service:service_manager find;
allow audioserver mediametrics_service:service_manager find;
allow audioserver sensor_privacy_service:service_manager find;
allow audioserver soundtrigger_middleware_service:service_manager find;
allow audioserver audio_service:service_manager find;

# Allow read/write access to bluetooth-specific properties
set_prop(audioserver, bluetooth_a2dp_offload_prop)
set_prop(audioserver, bluetooth_audio_hal_prop)
set_prop(audioserver, bluetooth_prop)
set_prop(audioserver, exported_bluetooth_prop)

# Grant access to audio files to audioserver
allow audioserver audio_data_file:dir ra_dir_perms;
allow audioserver audio_data_file:file create_file_perms;

# allow access to ALSA MMAP FDs for AAudio API
allow audioserver audio_device:chr_file { read write };

not_full_treble(`allow audioserver audio_device:dir r_dir_perms;')
not_full_treble(`allow audioserver audio_device:chr_file rw_file_perms;')

# For A2DP bridge which is loaded directly into audioserver
unix_socket_connect(audioserver, bluetooth, bluetooth)

# Allow shell commands from ADB and shell for CTS testing/dumping
allow audioserver adbd:fd use;
allow audioserver adbd:unix_stream_socket { read write };
allow audioserver shell:fifo_file { read write };

# Allow shell commands from ADB for CTS testing/dumping
userdebug_or_eng(`
  allow audioserver su:fd use;
  allow audioserver su:fifo_file { read write };
  allow audioserver su:unix_stream_socket { read write };
')

# Allow write access to log tag property
set_prop(audioserver, log_tag_prop);

# Allow audioserver to signal audio HAL processes and dump their stacks.
allow audioserver hal_audio_server:process signal;

# Allow audioserver to access sensorservice.
allow audioserver sensorservice_service:service_manager find;
allow audioserver system_server:unix_stream_socket { read write };

# Allow using wake locks
wakelock_use(audioserver)

# Allow reading audio config props, e.g. af.fast_track_multiplier
get_prop(audioserver, audio_config_prop)
get_prop(audioserver, system_audio_config_prop)

###
### neverallow rules
###

# audioserver should never execute any executable without a
# domain transition
neverallow audioserver { file_type fs_type }:file execute_no_trans;

# The goal of the mediaserver split is to place media processing code into
# restrictive sandboxes with limited responsibilities and thus limited
# permissions. Example: Audioserver is only responsible for controlling audio
# hardware and processing audio content. Cameraserver does the same for camera
# hardware/content. Etc.
#
# Media processing code is inherently risky and thus should have limited
# permissions and be isolated from the rest of the system and network.
# Lengthier explanation here:
# https://android-developers.googleblog.com/2016/05/hardening-media-stack.html
neverallow audioserver domain:{ udp_socket rawip_socket } *;
neverallow audioserver { domain userdebug_or_eng(`-su') }:tcp_socket *;