android_system_sepolicy/public/init.te

# init is its own domain.
type init, domain, domain_deprecated, mlstrustedsubject;

# The init domain is entered by execing init.
type init_exec, exec_type, file_type;

# /dev/__null__ node created by init.
allow init tmpfs:chr_file { create setattr unlink rw_file_perms };

#
# init direct restorecon calls.
#
# /dev/kmsg
allow init tmpfs:chr_file relabelfrom;
allow init kmsg_device:chr_file { write relabelto };
# /dev/__properties__
allow init properties_device:dir relabelto;
allow init properties_serial:file { write relabelto };
allow init property_type:file { create_file_perms relabelto };
# /dev/socket
allow init { device socket_device }:dir relabelto;
# /dev/random, /dev/urandom
allow init random_device:chr_file relabelto;
# /dev/device-mapper, /dev/block(/.*)?
allow init tmpfs:{ chr_file blk_file } relabelfrom;
allow init tmpfs:blk_file getattr;
allow init block_device:{ dir blk_file } relabelto;
allow init dm_device:{ chr_file blk_file } relabelto;
allow init kernel:fd use;

# setrlimit
allow init self:capability sys_resource;

# Remove /dev/.booting, created before initial policy load or restorecon /dev.
allow init tmpfs:file unlink;

# Access pty created for fsck.
allow init devpts:chr_file { read write open };

# Create /dev/fscklogs files.
allow init fscklogs:file create_file_perms;

# Access /dev/__null__ node created prior to initial policy load.
allow init tmpfs:chr_file write;

# Access /dev/console.
allow init console_device:chr_file rw_file_perms;

# Access /dev/tty0.
allow init tty_device:chr_file rw_file_perms;

# Call mount(2).
allow init self:capability sys_admin;

# Create and mount on directories in /.
allow init rootfs:dir create_dir_perms;
allow init { rootfs cache_file cgroup storage_file system_data_file system_file postinstall_mnt_dir }:dir mounton;

# Mount on /dev/usb-ffs/adb.
allow init device:dir mounton;

# Create and remove symlinks in /.
allow init rootfs:lnk_file { create unlink };

# Mount debugfs on /sys/kernel/debug.
allow init sysfs:dir mounton;

# Create cgroups mount points in tmpfs and mount cgroups on them.
allow init tmpfs:dir create_dir_perms;
allow init tmpfs:dir mounton;
allow init cgroup:dir create_dir_perms;
r_dir_file(init, cgroup)
allow init cpuctl_device:dir { create mounton };

# /config
allow init configfs:dir mounton;
allow init configfs:dir create_dir_perms;

# Use tmpfs as /data, used for booting when /data is encrypted
allow init tmpfs:dir relabelfrom;

# Create directories under /dev/cpuctl after chowning it to system.
allow init self:capability dac_override;

# Set system clock.
allow init self:capability sys_time;

allow init self:capability { sys_rawio mknod };

# Mounting filesystems from block devices.
allow init dev_type:blk_file r_file_perms;

# Mounting filesystems.
# Only allow relabelto for types used in context= mount options,
# which should all be assigned the contextmount_type attribute.
# This can be done in device-specific policy via type or typeattribute
# declarations.
allow init fs_type:filesystem ~relabelto;
allow init unlabeled:filesystem ~relabelto;
allow init contextmount_type:filesystem relabelto;

# Allow read-only access to context= mounted filesystems.
allow init contextmount_type:dir r_dir_perms;
allow init contextmount_type:notdevfile_class_set r_file_perms;

# restorecon /adb_keys or any other rootfs files and directories to a more
# specific type.
allow init rootfs:{ dir file } relabelfrom;

# mkdir, symlink, write, rm/rmdir, chown/chmod, restorecon/restorecon_recursive from init.rc files.
# chown/chmod require open+read+setattr required for open()+fchown/fchmod().
# system/core/init.rc requires at least cache_file and data_file_type.
# init.<board>.rc files often include device-specific types, so
# we just allow all file types except /system files here.
allow init self:capability { chown fowner fsetid };

allow init {
  file_type
  -app_data_file
  -exec_type
  -misc_logd_file
  -system_app_data_file
  -system_file
}:dir { create search getattr open read setattr ioctl };

allow init {
  file_type
  -app_data_file
  -exec_type
  -keystore_data_file
  -misc_logd_file
  -shell_data_file
  -system_app_data_file
  -system_file
  -vold_data_file
}:dir { write add_name remove_name rmdir relabelfrom };

allow init {
  file_type
  -app_data_file
  -exec_type
  -keystore_data_file
  -misc_logd_file
  -shell_data_file
  -system_app_data_file
  -system_file
  -vold_data_file
}:file { create getattr open read write setattr relabelfrom unlink };

allow init {
  file_type
  -app_data_file
  -exec_type
  -keystore_data_file
  -misc_logd_file
  -shell_data_file
  -system_app_data_file
  -system_file
  -vold_data_file
}:{ sock_file fifo_file } { create getattr open read setattr relabelfrom unlink };

allow init {
  file_type
  -app_data_file
  -exec_type
  -keystore_data_file
  -misc_logd_file
  -shell_data_file
  -system_app_data_file
  -system_file
  -vold_data_file
}:lnk_file { create getattr setattr relabelfrom unlink };

allow init {file_type -system_file -exec_type}:dir_file_class_set relabelto;
allow init { sysfs debugfs debugfs_tracing }:{ dir file lnk_file } { getattr relabelfrom };
allow init { sysfs_type debugfs_type }:{ dir file lnk_file } relabelto;
allow init dev_type:dir create_dir_perms;
allow init dev_type:lnk_file create;

# Disable tracing by writing to /sys/kernel/debug/tracing/tracing_on
allow init debugfs_tracing:file w_file_perms;

userdebug_or_eng(`
  # Setup and control wifi event tracing (see wifi-events.rc)
  allow init debugfs_tracing_instances:dir create_dir_perms;
  allow init debugfs_tracing_instances:file w_file_perms;
  allow init debugfs_wifi_tracing:file w_file_perms;
')

# chown/chmod on pseudo files.
allow init { fs_type -contextmount_type -sdcard_type -rootfs }:file { open read setattr };
allow init { fs_type -contextmount_type -sdcard_type -rootfs }:dir  { open read setattr search };

# chown/chmod on devices.
allow init { dev_type -kmem_device -port_device }:chr_file { read open setattr };

# Unlabeled file access for upgrades from 4.2.
allow init unlabeled:dir { create_dir_perms relabelfrom };
allow init unlabeled:notdevfile_class_set { create_file_perms relabelfrom };

# Any operation that can modify the kernel ring buffer, e.g. clear
# or a read that consumes the messages that were read.
allow init kernel:system syslog_mod;
allow init self:capability2 syslog;

# Set usermodehelpers and /proc security settings.
allow init usermodehelper:file rw_file_perms;
allow init proc_security:file rw_file_perms;

# Write to /proc/sys/kernel/panic_on_oops.
r_dir_file(init, proc)
allow init proc:file w_file_perms;

# Write to /proc/sys/net/ping_group_range and other /proc/sys/net files.
r_dir_file(init, proc_net)
allow init proc_net:file w_file_perms;
allow init self:capability net_admin;

# Write to /proc/sysrq-trigger.
allow init proc_sysrq:file w_file_perms;

# Read /proc/stat for bootchart.
allow init proc_stat:file r_file_perms;

# Reboot.
allow init self:capability sys_boot;

# Write to sysfs nodes.
allow init sysfs_type:dir r_dir_perms;
allow init sysfs_type:lnk_file read;
allow init sysfs_type:file rw_file_perms;

# Init will create /data/misc/logd when the property persist.logd.logpersistd is "logcatd".
# Init will also walk through the directory as part of a recursive restorecon.
allow init misc_logd_file:dir { open create read getattr setattr search };
allow init misc_logd_file:file { getattr };

# Support "adb shell stop"
allow init self:capability kill;
allow init domain:process { sigkill signal };

# Init creates keystore's directory on boot, and walks through
# the directory as part of a recursive restorecon.
allow init keystore_data_file:dir { open create read getattr setattr search };
allow init keystore_data_file:file { getattr };

# Init creates vold's directory on boot, and walks through
# the directory as part of a recursive restorecon.
allow init vold_data_file:dir { open create read getattr setattr search };
allow init vold_data_file:file { getattr };

# Init creates /data/local/tmp at boot
allow init shell_data_file:dir { open create read getattr setattr search };
allow init shell_data_file:file { getattr };

# Set UID, GID, and adjust capability bounding set for services.
allow init self:capability { setuid setgid setpcap };

# For bootchart to read the /proc/$pid/cmdline file of each process,
# we need to have following line to allow init to have access
# to different domains.
r_dir_file(init, domain)

# Use setexeccon(), setfscreatecon(), and setsockcreatecon().
# setexec is for services with seclabel options.
# setfscreate is for labeling directories and socket files.
# setsockcreate is for labeling local/unix domain sockets.
allow init self:process { setexec setfscreate setsockcreate };

# Perform SELinux access checks on setting properties.
selinux_check_access(init)

# Ask the kernel for the new context on services to label their sockets.
allow init kernel:security compute_create;

# Create sockets for the services.
allow init domain:unix_stream_socket { create bind };
allow init domain:unix_dgram_socket { create bind };

# Create /data/property and files within it.
allow init property_data_file:dir create_dir_perms;
allow init property_data_file:file create_file_perms;

# Set any property.
allow init property_type:property_service set;

# Send an SELinux userspace denial to the kernel audit subsystem,
# so it can be picked up and processed by logd. These denials are
# generated when an attempt to set a property is denied by policy.
allow init self:netlink_audit_socket { create_socket_perms_no_ioctl nlmsg_relay };
allow init self:capability audit_write;

# Run "ifup lo" to bring up the localhost interface
allow init self:udp_socket { create ioctl };
# in addition to unpriv ioctls granted to all domains, init also needs:
allowxperm init self:udp_socket ioctl SIOCSIFFLAGS;
allow init self:capability net_raw;

# This line seems suspect, as it should not really need to
# set scheduling parameters for a kernel domain task.
allow init kernel:process setsched;

# swapon() needs write access to swap device
# system/core/fs_mgr/fs_mgr.c - fs_mgr_swapon_all
allow init swap_block_device:blk_file rw_file_perms;

# Read from /dev/hw_random if present.
# system/core/init/init.c - mix_hwrng_into_linux_rng_action
allow init hw_random_device:chr_file r_file_perms;

# Create and access /dev files without a specific type,
# e.g. /dev/.coldboot_done, /dev/.booting
# TODO:  Move these files into their own type unless they are
# only ever accessed by init.
allow init device:file create_file_perms;

# Access character devices without a specific type,
# TODO: Remove this access and auditallow (b/33347297)
allow init device:chr_file { rw_file_perms setattr };
auditallow init device:chr_file { rw_file_perms setattr };

# keychord configuration
allow init self:capability sys_tty_config;
allow init keychord_device:chr_file rw_file_perms;

# Access device mapper for setting up dm-verity
allow init dm_device:chr_file rw_file_perms;
allow init dm_device:blk_file rw_file_perms;

# Access metadata block device for storing dm-verity state
allow init metadata_block_device:blk_file rw_file_perms;

# Read /sys/fs/pstore/console-ramoops to detect restarts caused
# by dm-verity detecting corrupted blocks
allow init pstorefs:dir search;
allow init pstorefs:file r_file_perms;
allow init kernel:system syslog_read;

# linux keyring configuration
allow init init:key { write search setattr };

# Allow init to create /data/unencrypted
allow init unencrypted_data_file:dir create_dir_perms;

# Allow init to write to /proc/sys/vm/overcommit_memory
allow init proc_overcommit_memory:file { write };

unix_socket_connect(init, vold, vold)

# Raw writes to misc block device
allow init misc_block_device:blk_file w_file_perms;

r_dir_file(init, system_file)
allow init proc_meminfo:file r_file_perms;

allow init system_data_file:file { getattr read };
allow init system_data_file:lnk_file r_file_perms;


###
### neverallow rules
###

# The init domain is only entered via an exec based transition from the
# kernel domain, never via setcon().
neverallow domain init:process dyntransition;
neverallow { domain -kernel } init:process transition;
neverallow init { file_type fs_type -init_exec }:file entrypoint;

# Never read/follow symlinks created by shell or untrusted apps.
neverallow init shell_data_file:lnk_file read;
neverallow init app_data_file:lnk_file read;

# init should never execute a program without changing to another domain.
neverallow init { file_type fs_type }:file execute_no_trans;

# Init never adds or uses services via service_manager.
neverallow init service_manager_type:service_manager { add find };
neverallow init servicemanager:service_manager list;

# Init should not be creating subdirectories in /data/local/tmp
neverallow init shell_data_file:dir { write add_name remove_name };