platform_system_sepolicy/untrusted_app.te
Calin Juravle 837bc42f5f Add SElinux policies to allow foreign dex usage tracking.
This is a special profile folder where apps will leave profile markers
for the dex files they load and don't own. System server will read the
markers and decide which apk should be fully compiled instead of
profile guide compiled.

Apps need only to be able to create (touch) files in this directory.
System server needs only to be able to check wheter or not a file with a
given name exists.

Bug: 27334750
Bug: 26080105

Change-Id: I2256e4aba1ec0e5117de6497123223b9a74f404e
2016-03-01 15:50:08 +00:00

184 lines
7.5 KiB
Text

###
### 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 };
# ASEC
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;
# Read and write system app data files passed over Binder.
# Motivating case was /data/data/com.android.settings/cache/*.jpg for
# cropping or taking user photos.
allow untrusted_app system_app_data_file:file { read write getattr };
#
# Rules migrated from old app domains coalesced into untrusted_app.
# This includes what used to be media_app, shared_app, and release_app.
#
# 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;
# Traverse into /mnt/media_rw for bypassing FUSE daemon
# TODO: narrow this to just MediaProvider
allow untrusted_app mnt_media_rw_file:dir search;
# allow cts to query all services
allow untrusted_app servicemanager:service_manager list;
allow untrusted_app audioserver_service:service_manager find;
allow untrusted_app cameraserver_service:service_manager find;
allow untrusted_app drmserver_service:service_manager find;
allow untrusted_app healthd_service:service_manager find;
allow untrusted_app mediaserver_service:service_manager find;
allow untrusted_app mediaextractor_service:service_manager find;
allow untrusted_app mediacodec_service:service_manager find;
allow untrusted_app mediadrmserver_service:service_manager find;
allow untrusted_app nfc_service:service_manager find;
allow untrusted_app radio_service:service_manager find;
allow untrusted_app surfaceflinger_service:service_manager find;
allow untrusted_app app_api_service:service_manager find;
# Allow GMS core to access perfprofd output, which is stored
# in /data/misc/perfprofd/. GMS core will need to list all
# data stored in that directory to process them one by one.
userdebug_or_eng(`
allow untrusted_app perfprofd_data_file:file r_file_perms;
allow untrusted_app perfprofd_data_file:dir r_dir_perms;
')
# gdbserver for ndk-gdb ptrace attaches to app process.
allow untrusted_app self:process ptrace;
# Programs routinely attempt to scan through /system, looking
# for files. Suppress the denials when they occur.
dontaudit untrusted_app exec_type:file getattr;
# TODO: switch to meminfo service
allow untrusted_app proc_meminfo:file r_file_perms;
# https://code.google.com/p/chromium/issues/detail?id=586021
allow untrusted_app proc:file r_file_perms;
auditallow untrusted_app proc:file r_file_perms;
# access /proc/net/xt_qtguid/stats
r_dir_file(untrusted_app, proc_net)
###
### neverallow rules
###
# Receive or send uevent messages.
neverallow untrusted_app domain:netlink_kobject_uevent_socket *;
# Receive or send generic netlink messages
neverallow untrusted_app domain:netlink_socket *;
# Too much leaky information in debugfs. It's a security
# best practice to ensure these files aren't readable.
neverallow untrusted_app debugfs_type:file read;
# Do not allow untrusted apps to register services.
# Only trusted components of Android should be registering
# services.
neverallow untrusted_app service_manager_type:service_manager add;
# Do not allow untrusted_apps to connect to the property service
# or set properties. b/10243159
neverallow untrusted_app property_socket:sock_file write;
neverallow untrusted_app init:unix_stream_socket connectto;
neverallow untrusted_app property_type:property_service set;
# Do not allow untrusted_app to be assigned mlstrustedsubject.
# This would undermine the per-user isolation model being
# enforced via levelFrom=user in seapp_contexts and the mls
# constraints. As there is no direct way to specify a neverallow
# on attribute assignment, this relies on the fact that fork
# permission only makes sense within a domain (hence should
# never be granted to any other domain within mlstrustedsubject)
# and untrusted_app is allowed fork permission to itself.
neverallow untrusted_app mlstrustedsubject:process fork;
# Do not allow untrusted_app to hard link to any files.
# In particular, if untrusted_app links to other app data
# files, installd will not be able to guarantee the deletion
# of the linked to file. Hard links also contribute to security
# bugs, so we want to ensure untrusted_app never has this
# capability.
neverallow untrusted_app file_type:file link;
# Do not allow untrusted_app to access network MAC address file
neverallow untrusted_app sysfs_mac_address:file no_rw_file_perms;
# do not allow privileged socket ioctl commands
neverallowxperm untrusted_app domain:{ rawip_socket tcp_socket udp_socket } ioctl priv_sock_ioctls;
# Do not allow untrusted_app access to /cache
neverallow untrusted_app { cache_file cache_recovery_file }:dir ~{ r_dir_perms };
neverallow untrusted_app { cache_file cache_recovery_file }:file ~{ read getattr };
# Do not allow untrusted_app to set system properties.
neverallow untrusted_app property_socket:sock_file write;
neverallow untrusted_app property_type:property_service set;
# Do not allow untrusted_app to create/unlink files outside of its sandbox,
# internal storage or sdcard.
# World accessible data locations allow application to fill the device
# with unaccounted for data. This data will not get removed during
# application un-installation.
neverallow untrusted_app {
fs_type
-fuse # sdcard
file_type
-app_data_file # The apps sandbox itself
-media_rw_data_file # Internal storage. Known that apps can
# leave artfacts here after uninstall.
-user_profile_data_file # Access to profile files
-user_profile_foreign_dex_data_file # Access to profile files
userdebug_or_eng(`
-method_trace_data_file # only on ro.debuggable=1
-coredump_file # userdebug/eng only
')
}:dir_file_class_set { create unlink };
# Do not allow untrusted_app to directly open tun_device
neverallow untrusted_app tun_device:chr_file open;