platform_system_sepolicy/vold.te

# volume manager
type vold, domain;
type vold_exec, exec_type, file_type;

init_daemon_domain(vold)

# Switch to more restrictive domains when executing common tools
domain_auto_trans(vold, sgdisk_exec, sgdisk);
domain_auto_trans(vold, sdcardd_exec, sdcardd);

# For a handful of probing tools, we choose an even more restrictive
# domain when working with untrusted block devices
domain_trans(vold, shell_exec, blkid);
domain_trans(vold, shell_exec, blkid_untrusted);
domain_trans(vold, fsck_exec, fsck);
domain_trans(vold, fsck_exec, fsck_untrusted);

# Allow us to jump into execution domains of above tools
allow vold self:process setexec;

# For sgdisk launched through popen()
allow vold shell_exec:file rx_file_perms;

typeattribute vold mlstrustedsubject;
allow vold self:process setfscreate;
allow vold system_file:file x_file_perms;
allow vold block_device:dir create_dir_perms;
allow vold block_device:blk_file create_file_perms;
auditallow vold block_device:blk_file create_file_perms;
allow vold device:dir write;
allow vold devpts:chr_file rw_file_perms;
allow vold rootfs:dir mounton;
allow vold sdcard_type:dir mounton; # TODO: deprecated in M
allow vold sdcard_type:filesystem { mount remount unmount }; # TODO: deprecated in M
allow vold sdcard_type:dir create_dir_perms; # TODO: deprecated in M
allow vold sdcard_type:file create_file_perms; # TODO: deprecated in M

# Manage locations where storage is mounted
allow vold { mnt_media_rw_file storage_file sdcard_type }:dir create_dir_perms;
allow vold { mnt_media_rw_file storage_file sdcard_type }:file create_file_perms;

# Access to storage that backs emulated FUSE daemons for migration optimization
allow vold media_rw_data_file:dir create_dir_perms;
allow vold media_rw_data_file:file create_file_perms;

# Newly created storage dirs are always treated as mount stubs to prevent us
# from accidentally writing when the mount point isn't present.
type_transition vold storage_file:dir storage_stub_file;
type_transition vold mnt_media_rw_file:dir mnt_media_rw_stub_file;

# Allow mounting of storage devices
allow vold { mnt_media_rw_stub_file storage_stub_file }:dir { mounton create rmdir getattr setattr };
allow vold sdcard_type:filesystem { mount unmount remount };

# Manage per-user primary symlinks
allow vold mnt_user_file:dir create_dir_perms;
allow vold mnt_user_file:lnk_file create_file_perms;

# Allow to create and mount expanded storage
allow vold mnt_expand_file:dir { create_dir_perms mounton };
allow vold apk_data_file:dir { create getattr setattr };
allow vold shell_data_file:dir { create getattr setattr };

allow vold tmpfs:filesystem { mount unmount };
allow vold tmpfs:dir create_dir_perms;
allow vold tmpfs:dir mounton;
allow vold self:capability { net_admin dac_override mknod sys_admin chown fowner fsetid };
allow vold self:netlink_kobject_uevent_socket create_socket_perms;
allow vold app_data_file:dir search;
allow vold app_data_file:file rw_file_perms;
allow vold loop_device:blk_file create_file_perms;
allow vold vold_device:blk_file create_file_perms;
allow vold dm_device:chr_file rw_file_perms;
allow vold dm_device:blk_file rw_file_perms;
# For vold Process::killProcessesWithOpenFiles function.
allow vold domain:dir r_dir_perms;
allow vold domain:{ file lnk_file } r_file_perms;
allow vold domain:process { signal sigkill };
allow vold self:capability { sys_ptrace kill };

# XXX Label sysfs files with a specific type?
allow vold sysfs:file rw_file_perms;

write_klog(vold)

# Run fsck.
allow vold fsck_exec:file rx_file_perms;

# Log fsck results
allow vold fscklogs:dir rw_dir_perms;
allow vold fscklogs:file create_file_perms;

#
# Rules to support encrypted fs support.
#

# Unmount and mount the fs.
allow vold labeledfs:filesystem { mount unmount remount };

# Access /efs/userdata_footer.
# XXX Split into a separate type?
allow vold efs_file:file rw_file_perms;

# Create and mount on /data/tmp_mnt and management of expansion mounts
allow vold system_data_file:dir { create rw_dir_perms mounton setattr rmdir };

# Set scheduling policy of kernel processes
allow vold kernel:process setsched;

# Property Service
set_prop(vold, vold_prop)
set_prop(vold, powerctl_prop)
set_prop(vold, ctl_fuse_prop)

# ASEC
allow vold asec_image_file:file create_file_perms;
allow vold asec_image_file:dir rw_dir_perms;
security_access_policy(vold)
allow vold asec_apk_file:dir { create_dir_perms mounton relabelfrom relabelto };
allow vold asec_public_file:dir { relabelto setattr };
allow vold asec_apk_file:file { r_file_perms setattr relabelfrom relabelto };
allow vold asec_public_file:file { relabelto setattr };
# restorecon files in asec containers created on 4.2 or earlier.
allow vold unlabeled:dir { r_dir_perms setattr relabelfrom };
allow vold unlabeled:file { r_file_perms setattr relabelfrom };

# Handle wake locks (used for device encryption)
wakelock_use(vold)

# talk to batteryservice
binder_use(vold)
binder_call(vold, healthd)

# talk to keymaster
allow vold tee_device:chr_file rw_file_perms;

# Access userdata block device.
allow vold userdata_block_device:blk_file rw_file_perms;

# Access metadata block device used for encryption meta-data.
allow vold metadata_block_device:blk_file rw_file_perms;

# Allow vold to manipulate /data/unencrypted
allow vold unencrypted_data_file:{ file } create_file_perms;
allow vold unencrypted_data_file:dir create_dir_perms;

# Write to /proc/sys/vm/drop_caches
allow vold proc_drop_caches:file w_file_perms;

# Give vold a place where only vold can store files; everyone else is off limits
allow vold vold_data_file:dir create_dir_perms;
allow vold vold_data_file:file create_file_perms;

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

neverallow { domain -vold } vold_data_file:dir ~{ open create read getattr setattr search relabelto ioctl };
neverallow { domain -vold } vold_data_file:notdevfile_class_set ~{ relabelto getattr };
neverallow { domain -vold -init } vold_data_file:dir *;
neverallow { domain -vold -init } vold_data_file:notdevfile_class_set *;