platform_system_sepolicy/public/vold.te

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

# Read already opened /cache files.
allow vold cache_file:dir r_dir_perms;
allow vold cache_file:file { getattr read };
allow vold cache_file:lnk_file r_file_perms;

# Read access to pseudo filesystems.
r_dir_file(vold, proc_net_type)
userdebug_or_eng(`
  auditallow vold proc_net_type:{ dir file lnk_file } { getattr open read };
')

r_dir_file(vold, sysfs_type)
# XXX Label sysfs files with a specific type?
allow vold sysfs:file w_file_perms; # writing to /sys/*/uevent during coldboot.
allow vold sysfs_dm:file w_file_perms;
allow vold sysfs_usb:file w_file_perms;
allow vold sysfs_zram_uevent:file w_file_perms;

r_dir_file(vold, rootfs)
r_dir_file(vold, metadata_file)
allow vold {
  proc # b/67049235 processes /proc/<pid>/* files are mislabeled.
  proc_cmdline
  proc_drop_caches
  proc_filesystems
  proc_meminfo
  proc_mounts
}:file r_file_perms;

#Get file contexts
allow vold file_contexts_file:file r_file_perms;

# 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;

# For formatting adoptable storage devices
allow vold e2fs_exec:file rx_file_perms;

typeattribute vold mlstrustedsubject;
allow vold self:process setfscreate;
allow vold system_file:file x_file_perms;
not_full_treble(`allow vold vendor_file:file x_file_perms;')
allow vold block_device:dir create_dir_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;

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

# 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:global_capability_class_set { net_admin dac_override mknod sys_admin chown fowner fsetid };
allow vold self:netlink_kobject_uevent_socket create_socket_perms_no_ioctl;
# TODO(b/80418809): remove direct access to private app data
userdebug_or_eng(`auditallow vold app_data_file:dir search;')
allow vold app_data_file:dir search;
userdebug_or_eng(`auditallow vold app_data_file:file rw_file_perms;')
allow vold app_data_file:file rw_file_perms;
allow vold loop_control_device:chr_file rw_file_perms;
allow vold loop_device:blk_file { create setattr unlink rw_file_perms };
allow vold vold_device:blk_file { create setattr unlink rw_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:global_capability_class_set { sys_ptrace kill };

allow vold kmsg_device:chr_file rw_file_perms;

# Run fsck in the fsck domain.
allow vold fsck_exec:file { r_file_perms execute };

# 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 };

# 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 };
allow vold system_data_file:lnk_file getattr;

# Vold create users in /data/vendor_{ce,de}/[0-9]+
allow vold vendor_data_file:dir create_dir_perms;

# for secdiscard
allow vold system_data_file:file read;

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

# Property Service
set_prop(vold, vold_prop)
set_prop(vold, exported_vold_prop)
set_prop(vold, exported2_vold_prop)
set_prop(vold, powerctl_prop)
set_prop(vold, ctl_fuse_prop)
set_prop(vold, restorecon_prop)

# ASEC
allow vold asec_image_file:file create_file_perms;
allow vold asec_image_file:dir rw_dir_perms;
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)

# Allow vold to publish a binder service and make binder calls.
binder_use(vold)
add_service(vold, vold_service)

# Allow vold to call into the system server so it can check permissions.
binder_call(vold, system_server)
allow vold permission_service:service_manager find;

# talk to batteryservice
binder_call(vold, healthd)

# talk to keymaster
hal_client_domain(vold, hal_keymaster)

# 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;

# And a similar place in the metadata partition
allow vold vold_metadata_file:dir create_dir_perms;
allow vold vold_metadata_file:file create_file_perms;

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

# vold temporarily changes its priority when running benchmarks
allow vold self:global_capability_class_set sys_nice;

# vold needs to chroot into app namespaces to remount when runtime permissions change
allow vold self:global_capability_class_set sys_chroot;
allow vold storage_file:dir mounton;

# For AppFuse.
allow vold fuse_device:chr_file rw_file_perms;
allow vold fuse:filesystem { relabelfrom };
allow vold app_fusefs:filesystem { relabelfrom relabelto };
allow vold app_fusefs:filesystem { mount unmount };

# MoveTask.cpp executes cp and rm
allow vold toolbox_exec:file rx_file_perms;

# Prepare profile dir for users.
allow vold user_profile_data_file:dir create_dir_perms;

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

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

neverallow {
    domain
    -init
    -vold
    -vold_prepare_subdirs
} vold_data_file:dir *;

neverallow {
    domain
    -init
    -vendor_init
    -vold
} vold_metadata_file:dir *;

neverallow {
    domain
    -kernel
    -vold
    -vold_prepare_subdirs
} vold_data_file:notdevfile_class_set ~{ relabelto getattr };

neverallow {
    domain
    -init
    -vold
    -vold_prepare_subdirs
} vold_metadata_file:notdevfile_class_set ~{ relabelto getattr };

neverallow {
    domain
    -init
    -kernel
    -vendor_init
    -vold
    -vold_prepare_subdirs
} { vold_data_file vold_metadata_file }:notdevfile_class_set *;

neverallow { domain -vold -init } restorecon_prop:property_service set;

# Only system_server and vdc can interact with vold over binder
neverallow { domain -system_server -vdc -vold } vold_service:service_manager find;
neverallow vold {
  domain
  -hal_keymaster_server
  -healthd
  -hwservicemanager
  -servicemanager
  -system_server
  userdebug_or_eng(`-su')
}:binder call;

neverallow vold fsck_exec:file execute_no_trans;
neverallow { domain -init } vold:process { transition dyntransition };
neverallow vold *:process ptrace;
neverallow vold *:rawip_socket *;