platform_system_sepolicy/private/sdcardd.te

typeattribute sdcardd coredomain;

type_transition sdcardd system_data_file:{ dir file } media_rw_data_file;

allow sdcardd cgroup:dir create_dir_perms;
allow sdcardd cgroup_v2:dir create_dir_perms;
allow sdcardd fuse_device:chr_file rw_file_perms;
allow sdcardd rootfs:dir mounton;  # TODO: deprecated in M
allow sdcardd sdcardfs:filesystem remount;
allow sdcardd tmpfs:dir r_dir_perms;
allow sdcardd mnt_media_rw_file:dir r_dir_perms;
allow sdcardd storage_file:dir search;
allow sdcardd storage_stub_file:dir { search mounton };
allow sdcardd { sdcard_type fuse }:filesystem { mount unmount };
allow sdcardd self:global_capability_class_set { setuid setgid dac_override dac_read_search sys_admin sys_resource };

allow sdcardd { sdcard_type fuse }:dir create_dir_perms;
allow sdcardd { sdcard_type fuse }:file create_file_perms;

allow sdcardd media_rw_data_file:dir create_dir_perms;
allow sdcardd media_rw_data_file:file create_file_perms;

# Read /data/system/packages.list.
allow sdcardd system_data_file:file r_file_perms;
allow sdcardd packages_list_file:file r_file_perms;

# Read /data/misc/installd/layout_version
allow sdcardd install_data_file:file r_file_perms;
allow sdcardd install_data_file:dir search;

# Allow stdin/out back to vold
allow sdcardd vold:fd use;
allow sdcardd vold:fifo_file { read write getattr };

# Allow running on top of expanded storage
allow sdcardd mnt_expand_file:dir search;

# access /proc/filesystems
allow sdcardd proc_filesystems:file r_file_perms;

###
### neverallow rules
###

# The sdcard daemon should no longer be started from init
neverallow init sdcardd_exec:file execute;
neverallow init sdcardd:process { transition dyntransition };