android_system_sepolicy/untrusted_app.te

###
### Untrusted apps.
###
### This file defines the rules for untrusted apps.
### Apps are labeled based on mac_permissions.xml (maps signer and
### optionally package name to seinfo value) and seapp_contexts (maps UID
### and optionally seinfo value to domain for process and type for data
### directory).  The untrusted_app domain is the default assignment in
### seapp_contexts for any app with UID between APP_AID (10000)
### and AID_ISOLATED_START (99000) if the app has no specific seinfo
### value as determined from mac_permissions.xml.  In current AOSP, this
### domain is assigned to all non-system apps as well as to any system apps
### that are not signed by the platform key.  To move
### a system app into a specific domain, add a signer entry for it to
### mac_permissions.xml and assign it one of the pre-existing seinfo values
### or define and use a new seinfo value in both mac_permissions.xml and
### seapp_contexts.
###
### untrusted_app includes all the appdomain rules, plus the
### additional following rules:
###

type untrusted_app, domain;
app_domain(untrusted_app)
net_domain(untrusted_app)
bluetooth_domain(untrusted_app)

# Some apps ship with shared libraries and binaries that they write out
# to their sandbox directory and then execute.
allow untrusted_app app_data_file:file { rx_file_perms execmod };

allow untrusted_app tun_device:chr_file rw_file_perms;

# ASEC
allow untrusted_app asec_apk_file:dir { getattr };
allow untrusted_app asec_apk_file:file r_file_perms;
# Execute libs in asec containers.
allow untrusted_app asec_public_file:file { execute execmod };

# Allow the allocation and use of ptys
# Used by: https://play.google.com/store/apps/details?id=jackpal.androidterm
create_pty(untrusted_app)

# Used by Finsky / Android "Verify Apps" functionality when
# running "adb install foo.apk".
# TODO: Long term, we don't want apps probing into shell data files.
# Figure out a way to remove these rules.
allow untrusted_app shell_data_file:file r_file_perms;
allow untrusted_app shell_data_file:dir r_dir_perms;

#
# Rules migrated from old app domains coalesced into untrusted_app.
# This includes what used to be media_app, shared_app, and release_app.
#

# Access /dev/mtp_usb.
allow untrusted_app mtp_device:chr_file rw_file_perms;

# Access to /data/media.
allow untrusted_app media_rw_data_file:dir create_dir_perms;
allow untrusted_app media_rw_data_file:file create_file_perms;

# Write to /cache.
allow untrusted_app cache_file:dir create_dir_perms;
allow untrusted_app cache_file:file create_file_perms;

###
### neverallow rules
###

# Too much leaky information in debugfs. It's a security
# best practice to ensure these files aren't readable.
neverallow untrusted_app debugfs:file read;