microdroid/system/private/init.te

typeattribute init coredomain;

tmpfs_domain(init)

domain_trans(init, shell_exec, shell)
domain_trans(init, init_exec, ueventd)
domain_trans(init, init_exec, vendor_init)

# Allow init to figure out name of dm-device from it's /dev/block/dm-XX path.
# This is useful in case of remounting ext4 userdata into checkpointing mode,
# since it potentially requires tearing down dm-devices (e.g. dm-bow, dm-crypto)
# that userdata is mounted onto.
allow init sysfs_dm:file read;

# Second-stage init performs a test for whether the kernel has SELinux hooks
# for the perf_event_open() syscall. This is done by testing for the syscall
# outcomes corresponding to this policy.
allow init self:perf_event { open cpu };
allow init self:global_capability2_class_set perfmon;
dontaudit init self:perf_event { kernel tracepoint read write };

# Allow opening /proc/kallsyms so that on boot, init can create and retain an
# fd with the full address visibility (which is evaluated on open and persists
# for the lifetime of the open file description). This fd can then be shared
# with other privileged processes.
allow init proc_kallsyms:file r_file_perms;

# Allow init to restore contexts of vd_device(/dev/block/vd[..]) when labeling
# /dev/block.
allow init vd_device:blk_file relabelto;

# chown/chmod on devices.
allow init {
  dev_type
  -hw_random_device
}:chr_file setattr;

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

# /dev/__properties__ and /dev/__properties__/appcompat_override
allow init properties_device:dir relabelto;
allow init properties_serial:file { write relabelto };
allow init property_type:file { append create getattr map open read relabelto rename setattr unlink write };
# /dev/__properties__/property_info and /dev/__properties__/appcompat_override/property_info
allow init properties_device:file create_file_perms;
allow init property_info:file relabelto;
# /dev/socket
allow init { device socket_device dm_user_device }:dir relabelto;
# Relabel /dev nodes created in first stage init: /dev/console, /dev/null, /dev/ptmx, /dev/random
# and /dev/urandom
allow init { console_device null_device ptmx_device 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 lnk_file } relabelto;
allow init dm_device:{ chr_file blk_file } relabelto;
allow init dm_user_device:chr_file relabelto;
allow init kernel:fd use;
# restorecon for early mount device symlinks
allow init tmpfs:lnk_file { getattr read relabelfrom };

# setrlimit
allow init self:global_capability_class_set sys_resource;

# Set usermodehelpers.
allow init { usermodehelper sysfs_usermodehelper }:file rw_file_perms;

# Remove /dev/.booting and load /debug_ramdisk/* files
allow init tmpfs:file { getattr unlink };

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

# 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:global_capability_class_set sys_admin;

# Call setns(2).
allow init self:global_capability_class_set sys_chroot;

# Create and mount on directories in /.
allow init rootfs:dir create_dir_perms;
allow init {
    rootfs
    cgroup
    linkerconfig_file
    system_data_file
    system_data_root_file
    system_file
    vendor_file
}:dir mounton;

# Mount bpf fs on sys/fs/bpf
allow init fs_bpf:dir mounton;

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

# Mount tmpfs on /apex
allow init apex_mnt_dir: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;
allow init cgroup:file rw_file_perms;
allow init cgroup_desc_file:file r_file_perms;
allow init cgroup_v2:dir { mounton create_dir_perms};
allow init cgroup_v2:file rw_file_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:global_capability_class_set { dac_override dac_read_search };

allow init self:global_capability_class_set { sys_rawio mknod };

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

# 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 to mount tracefs in /sys/kernel/tracing
allow init debugfs_tracing_debug:filesystem mount;

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:global_capability_class_set { chown fowner fsetid };

allow init {
  file_type
  -exec_type
  -system_file_type
  -vendor_file_type
}:dir { create search getattr open read setattr ioctl };

allow init {
  file_type
  -exec_type
  -shell_data_file
  -system_file_type
  -vendor_file_type
}:dir { write add_name remove_name rmdir relabelfrom };

allow init {
  file_type
  -apex_info_file
  -exec_type
  -shell_data_file
  -system_file_type
  -vendor_file_type
}:file { create getattr open read write setattr relabelfrom unlink map };

allow init tracefs_type:file { create_file_perms relabelfrom };

allow init {
  file_type
  -exec_type
  -shell_data_file
  -system_file_type
  -vendor_file_type
}:{ sock_file fifo_file } { create getattr open read setattr relabelfrom unlink };

allow init {
  file_type
  -apex_mnt_dir
  -exec_type
  -shell_data_file
  -system_file_type
  -vendor_file_type
}:lnk_file { create getattr setattr relabelfrom unlink };

allow init {
  file_type
  -system_file_type
  -vendor_file_type
  -exec_type
}:dir_file_class_set relabelto;

allow init { sysfs debugfs_tracing debugfs_tracing_debug }:{ dir file lnk_file } { getattr relabelfrom };
allow init { sysfs_type tracefs_type }:{ dir file lnk_file } { relabelto getattr };
allow init dev_type:dir create_dir_perms;
allow init dev_type:lnk_file create;

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

allow init {
  console_device
  devpts
  dm_device
  kmsg_device
  null_device
  owntty_device
  ptmx_device
  random_device
  tty_device
  zero_device
}:chr_file { read open };

# 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:global_capability2_class_set syslog;

# init access to /proc.
r_dir_file(init, proc_net_type)
allow init proc_filesystems:file r_file_perms;

allow init {
  proc # b/67049235 processes /proc/<pid>/* files are mislabeled.
  proc_bootconfig
  proc_cmdline
  proc_diskstats
  proc_kmsg # Open /proc/kmsg for logd service.
  proc_meminfo
  proc_stat # Read /proc/stat for bootchart.
  proc_uptime
  proc_version
}:file r_file_perms;

allow init {
  proc_abi
  proc_dirty
  proc_hostname
  proc_hung_task
  proc_extra_free_kbytes
  proc_net_type
  proc_max_map_count
  proc_min_free_order_shift
  proc_overcommit_memory      # /proc/sys/vm/overcommit_memory
  proc_panic
  proc_page_cluster
  proc_perf
  proc_sched
  proc_sysrq
}:file w_file_perms;

allow init {
  proc_security
}:file rw_file_perms;

# init chmod/chown access to /proc files.
allow init {
  proc_cmdline
  proc_bootconfig
  proc_kmsg
  proc_net
  proc_pagetypeinfo
  proc_qtaguid_stat
  proc_slabinfo
  proc_sysrq
  proc_qtaguid_ctrl
  proc_vmallocinfo
}:file setattr;

# init access to /sys files.
allow init {
  sysfs_android_usb
  sysfs_dm_verity
  sysfs_leds
  sysfs_power
  sysfs_fs_f2fs
  sysfs_dm
  sysfs_pgsize_migration
}:file w_file_perms;

allow init {
  sysfs_dt_firmware_android
  sysfs_fs_ext4_features
}:file r_file_perms;

allow init {
  sysfs_zram
}:file rw_file_perms;

# allow init to create loop devices with /dev/loop-control
allow init loop_control_device:chr_file rw_file_perms;
allow init loop_device:blk_file rw_file_perms;
allowxperm init loop_device:blk_file ioctl {
  LOOP_SET_FD
  LOOP_CLR_FD
  LOOP_CTL_GET_FREE
  LOOP_SET_BLOCK_SIZE
  LOOP_SET_DIRECT_IO
  LOOP_GET_STATUS
};

# init chmod/chown access to /sys files.
allow init {
  sysfs_android_usb
  sysfs_devices_system_cpu
  sysfs_ipv4
  sysfs_leds
  sysfs_lowmemorykiller
  sysfs_power
  sysfs_vibrator
  sysfs_wake_lock
  sysfs_zram
}:file setattr;

allow init self:global_capability_class_set net_admin;

# Reboot.
allow init self:global_capability_class_set sys_boot;

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

# 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:global_capability_class_set { 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 };

# Get file context
allow init file_contexts_file:file r_file_perms;

# sepolicy access
allow init sepolicy_file:file r_file_perms;

# 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 setopt };
allow init domain:unix_dgram_socket { create bind setopt };

# 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:global_capability_class_set 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:global_capability_class_set net_raw;

# Set scheduling info for psi monitor thread.
# TODO: delete or revise this line b/131761776
allow init kernel:process { getsched setsched };

# 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 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;

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

r_dir_file(init, system_file)
r_dir_file(init, vendor_file_type)

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

# Allow init to touch PSI monitors
allow init proc_pressure_mem:file { rw_file_perms setattr };

# init is using bootstrap bionic
use_bootstrap_libs(init)

# stat the root dir of fuse filesystems (for the mount handler)
allow init fuse:dir { search getattr };

set_prop(init, property_type)

allow init self:netlink_audit_socket { create_socket_perms_no_ioctl nlmsg_relay };

# PRNG seeder daemon socket is created and listened on by init before forking.
allow init prng_seeder:unix_stream_socket { create bind listen };

# Allow init to load vendor modules
r_dir_file(init, vendor_kernel_modules)
allow init self:capability sys_module;
allow init vendor_kernel_modules:system module_load;

allow init tmpfs:chr_file relabelfrom;
allow init kmsg_device:chr_file { getattr write relabelto };
allow init kmsg_debug_device:chr_file { open write relabelto };