From fce60d3dbc2efe0acfc538a5c73bba2baf67e22f Mon Sep 17 00:00:00 2001
From: Alex Klyubin <klyubin@google.com>
Date: Thu, 5 Jan 2017 12:27:10 -0800
Subject: [PATCH] Move untrusted_app policy to private

This leaves only the existence of untrusted_app domain as public API.
All other rules are implementation details of this domain's policy and
are thus now private.

Test: No change to policy according to sesearch, except for
      disappearance of all allow rules from untrusted_domain_current
      attribute (as expected).
Bug: 31364497

Change-Id: Ief71fa16cfc38437cbe5c58100bba48b9a497c92
---
 private/untrusted_app.te | 196 +++++++++++++++++++++++++++++++++++++++
 public/untrusted_app.te  | 182 ------------------------------------
 2 files changed, 196 insertions(+), 182 deletions(-)

diff --git a/private/untrusted_app.te b/private/untrusted_app.te
index b142ebfa0..57c82de41 100644
--- a/private/untrusted_app.te
+++ b/private/untrusted_app.te
@@ -1,5 +1,201 @@
+###
+### 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.
+###
+
 app_domain(untrusted_app)
+net_domain(untrusted_app)
+bluetooth_domain(untrusted_app)
 
 # Allow the allocation and use of ptys
 # Used by: https://play.google.com/store/apps/details?id=jackpal.androidterm
 create_pty(untrusted_app)
+
+# Legacy text relocations
+allow untrusted_app apk_data_file:file execmod;
+
+# 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;
+allow untrusted_app asec_apk_file:dir r_dir_perms;
+# Execute libs in asec containers.
+allow untrusted_app asec_public_file:file { execute execmod };
+
+# 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 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;
+
+# Cts: HwRngTest
+allow untrusted_app sysfs_hwrandom:dir search;
+allow untrusted_app sysfs_hwrandom:file r_file_perms;
+
+# Allow apps to view preloaded content
+allow untrusted_app preloads_data_file:dir r_dir_perms;
+allow untrusted_app preloads_data_file:file r_file_perms;
+
+# Access to /proc/tty/drivers, to allow apps to determine if they
+# are running in an emulated environment.
+# b/33214085 b/33814662 b/33791054 b/33211769
+# https://github.com/strazzere/anti-emulator/blob/master/AntiEmulator/src/diff/strazzere/anti/emulator/FindEmulator.java
+allow untrusted_app proc_tty_drivers:file r_file_perms;
+
+###
+### 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;
+
+# Restrict socket ioctls. Either 1. disallow privileged ioctls, 2. disallow the
+# ioctl permission, or 3. disallow the socket class.
+neverallowxperm untrusted_app domain:{ rawip_socket tcp_socket udp_socket } ioctl priv_sock_ioctls;
+neverallow untrusted_app *:{ netlink_route_socket netlink_selinux_socket } ioctl;
+neverallow untrusted_app *:{
+  socket netlink_socket packet_socket key_socket appletalk_socket
+  netlink_firewall_socket netlink_tcpdiag_socket netlink_nflog_socket
+  netlink_xfrm_socket netlink_audit_socket netlink_ip6fw_socket
+  netlink_dnrt_socket netlink_kobject_uevent_socket tun_socket
+  netlink_iscsi_socket netlink_fib_lookup_socket netlink_connector_socket
+  netlink_netfilter_socket netlink_generic_socket netlink_scsitransport_socket
+  netlink_rdma_socket netlink_crypto_socket
+} *;
+
+# 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 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
+  -sdcardfs                 # sdcard
+  -vfat
+  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;
+
+# Only allow appending to /data/anr/traces.txt (b/27853304, b/18340553)
+neverallow untrusted_app anr_data_file:file ~{ open append };
+neverallow untrusted_app anr_data_file:dir ~search;
+
+# Avoid reads from generically labeled /proc files
+# Create a more specific label if needed
+neverallow untrusted_app proc:file { no_rw_file_perms no_x_file_perms };
diff --git a/public/untrusted_app.te b/public/untrusted_app.te
index 827334287..6f29396c3 100644
--- a/public/untrusted_app.te
+++ b/public/untrusted_app.te
@@ -1,7 +1,6 @@
 ###
 ### 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
@@ -16,186 +15,5 @@
 ### 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;
-
-net_domain(untrusted_app)
-bluetooth_domain(untrusted_app)
-
-# Legacy text relocations
-allow untrusted_app apk_data_file:file execmod;
-
-# 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;
-allow untrusted_app asec_apk_file:dir r_dir_perms;
-# Execute libs in asec containers.
-allow untrusted_app asec_public_file:file { execute execmod };
-
-# 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 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;
-
-# Cts: HwRngTest
-allow untrusted_app sysfs_hwrandom:dir search;
-allow untrusted_app sysfs_hwrandom:file r_file_perms;
-
-# Allow apps to view preloaded content
-allow untrusted_app preloads_data_file:dir r_dir_perms;
-allow untrusted_app preloads_data_file:file r_file_perms;
-
-# Access to /proc/tty/drivers, to allow apps to determine if they
-# are running in an emulated environment.
-# b/33214085 b/33814662 b/33791054 b/33211769
-# https://github.com/strazzere/anti-emulator/blob/master/AntiEmulator/src/diff/strazzere/anti/emulator/FindEmulator.java
-allow untrusted_app proc_tty_drivers:file r_file_perms;
-
-###
-### 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;
-
-# Restrict socket ioctls. Either 1. disallow privileged ioctls, 2. disallow the
-# ioctl permission, or 3. disallow the socket class.
-neverallowxperm untrusted_app domain:{ rawip_socket tcp_socket udp_socket } ioctl priv_sock_ioctls;
-neverallow untrusted_app *:{ netlink_route_socket netlink_selinux_socket } ioctl;
-neverallow untrusted_app *:{
-  socket netlink_socket packet_socket key_socket appletalk_socket
-  netlink_firewall_socket netlink_tcpdiag_socket netlink_nflog_socket
-  netlink_xfrm_socket netlink_audit_socket netlink_ip6fw_socket
-  netlink_dnrt_socket netlink_kobject_uevent_socket tun_socket
-  netlink_iscsi_socket netlink_fib_lookup_socket netlink_connector_socket
-  netlink_netfilter_socket netlink_generic_socket netlink_scsitransport_socket
-  netlink_rdma_socket netlink_crypto_socket
-} *;
-
-# 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 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
-  -sdcardfs                 # sdcard
-  -vfat
-  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;
-
-# Only allow appending to /data/anr/traces.txt (b/27853304, b/18340553)
-neverallow untrusted_app anr_data_file:file ~{ open append };
-neverallow untrusted_app anr_data_file:dir ~search;
-
-# Avoid reads from generically labeled /proc files
-# Create a more specific label if needed
-neverallow untrusted_app proc:file { no_rw_file_perms no_x_file_perms };
-- 
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