android_system_sepolicy/public/fastbootd.te

# fastbootd (used in recovery init.rc for /sbin/fastbootd)

# Declare the domain unconditionally so we can always reference it
# in neverallow rules.
type fastbootd, domain;

# But the allow rules are only included in the recovery policy.
# Otherwise fastbootd is only allowed the domain rules.
recovery_only(`
  # fastbootd can only use HALs in passthrough mode
  passthrough_hal_client_domain(fastbootd, hal_bootctl)

  # Access /dev/usb-ffs/fastbootd/ep0
  allow fastbootd functionfs:dir search;
  allow fastbootd functionfs:file rw_file_perms;

  # Log to serial
  allow fastbootd kmsg_device:chr_file { open write };

  # battery info
  allow fastbootd sysfs_batteryinfo:file r_file_perms;

  allow fastbootd device:dir r_dir_perms;

  # Reboot the device
  set_prop(fastbootd, powerctl_prop)

  # Read serial number of the device from system properties
  get_prop(fastbootd, serialno_prop)

  # Set sys.usb.ffs.ready.
  set_prop(fastbootd, ffs_prop)
  set_prop(fastbootd, exported_ffs_prop)

  unix_socket_connect(fastbootd, recovery, recovery)

  # Required for flashing
  allow fastbootd dm_device:chr_file rw_file_perms;
  allow fastbootd dm_device:blk_file rw_file_perms;

  allow fastbootd super_block_device:blk_file rw_file_perms;
  allow fastbootd system_block_device:blk_file rw_file_perms;
  allow fastbootd boot_block_device:blk_file rw_file_perms;

  allow fastbootd misc_block_device:blk_file rw_file_perms;

  # Required to wipe userdata
  allow fastbootd userdata_block_device:blk_file { w_file_perms getattr ioctl };
  allowxperm fastbootd userdata_block_device:blk_file ioctl { BLKGETSIZE64 BLKSECDISCARD
                                                              BLKDISCARD };

  allow fastbootd proc_cmdline:file r_file_perms;
  allow fastbootd rootfs:dir r_dir_perms;
  allow fastbootd sysfs_dt_firmware_android:file r_file_perms;
')

###
### neverallow rules
###

# Write permission is required to wipe userdata
# until recovery supports vold.
neverallow fastbootd {
   data_file_type
}:file { no_x_file_perms };