23c9d91b46
Currently, both untrusted apps and priv-apps use the SELinux file label
"app_data_file" for files in their /data/data directory. This is
problematic, as we really want different rules for such files. For
example, we may want to allow untrusted apps to load executable code
from priv-app directories, but disallow untrusted apps from loading
executable code from their own home directories.
This change adds a new file type "privapp_data_file". For compatibility,
we adjust the policy to support access privapp_data_files almost
everywhere we were previously granting access to app_data_files
(adbd and run-as being exceptions). Additional future tightening is
possible here by removing some of these newly added rules.
This label will start getting used in a followup change to
system/sepolicy/private/seapp_contexts, similar to:
-user=_app isPrivApp=true domain=priv_app type=app_data_file levelFrom=user
+user=_app isPrivApp=true domain=priv_app type=privapp_data_file levelFrom=user
For now, this newly introduced label has no usage, so this change
is essentially a no-op.
Test: Factory reset and boot - no problems on fresh install.
Test: Upgrade to new version and test. No compatibility problems on
filesystem upgrade.
Change-Id: I9618b7d91d1c2bcb5837cdabc949f0cf741a2837
155 lines
7 KiB
Text
155 lines
7 KiB
Text
###
|
|
### Untrusted_app_all.
|
|
###
|
|
### This file defines the rules shared by all untrusted app domains except
|
|
### apps which target the v2 security sandbox (ephemeral_app for instant apps,
|
|
### untrusted_v2_app for fully installed v2 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_all attribute is assigned to all default
|
|
### 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
|
|
### attribute 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.
|
|
###
|
|
### Note that rules that should apply to all untrusted apps must be in app.te or also
|
|
### added to untrusted_v2_app.te and ephemeral_app.te.
|
|
|
|
# Some apps ship with shared libraries and binaries that they write out
|
|
# to their sandbox directory and then execute.
|
|
allow untrusted_app_all { app_data_file privapp_data_file }:file { rx_file_perms };
|
|
|
|
# ASEC
|
|
allow untrusted_app_all asec_apk_file:file r_file_perms;
|
|
allow untrusted_app_all asec_apk_file:dir r_dir_perms;
|
|
# Execute libs in asec containers.
|
|
allow untrusted_app_all asec_public_file:file { execute };
|
|
|
|
# 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_all shell_data_file:file r_file_perms;
|
|
allow untrusted_app_all shell_data_file:dir r_dir_perms;
|
|
|
|
# Allow traceur to pass file descriptors through a content provider to untrusted apps
|
|
# for the purpose of sharing files through e.g. gmail
|
|
allow untrusted_app_all trace_data_file:file { getattr read };
|
|
|
|
# untrusted apps should not be able to open trace data files, they should depend
|
|
# upon traceur to pass a file descriptor
|
|
neverallow untrusted_app_all trace_data_file:dir *;
|
|
neverallow untrusted_app_all trace_data_file:file { no_w_file_perms open };
|
|
|
|
# Allow to read staged apks.
|
|
allow untrusted_app_all { apk_tmp_file apk_private_tmp_file }:file {read getattr};
|
|
|
|
# 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_all 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_all media_rw_data_file:dir create_dir_perms;
|
|
allow untrusted_app_all 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_all mnt_media_rw_file:dir search;
|
|
|
|
# allow cts to query all services
|
|
allow untrusted_app_all servicemanager:service_manager list;
|
|
|
|
allow untrusted_app_all audioserver_service:service_manager find;
|
|
allow untrusted_app_all cameraserver_service:service_manager find;
|
|
allow untrusted_app_all drmserver_service:service_manager find;
|
|
allow untrusted_app_all mediaserver_service:service_manager find;
|
|
allow untrusted_app_all mediaextractor_service:service_manager find;
|
|
allow untrusted_app_all mediacodec_service:service_manager find;
|
|
allow untrusted_app_all mediametrics_service:service_manager find;
|
|
allow untrusted_app_all mediadrmserver_service:service_manager find;
|
|
allow untrusted_app_all nfc_service:service_manager find;
|
|
allow untrusted_app_all radio_service:service_manager find;
|
|
allow untrusted_app_all app_api_service:service_manager find;
|
|
allow untrusted_app_all vr_manager_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_all perfprofd_data_file:file r_file_perms;
|
|
allow untrusted_app_all perfprofd_data_file:dir r_dir_perms;
|
|
')
|
|
|
|
# gdbserver for ndk-gdb ptrace attaches to app process.
|
|
allow untrusted_app_all self:process ptrace;
|
|
|
|
# Cts: HwRngTest
|
|
allow untrusted_app_all sysfs_hwrandom:dir search;
|
|
allow untrusted_app_all sysfs_hwrandom:file r_file_perms;
|
|
|
|
# Allow apps to view preloaded media content
|
|
allow untrusted_app_all preloads_media_file:dir r_dir_perms;
|
|
allow untrusted_app_all preloads_media_file:file r_file_perms;
|
|
allow untrusted_app_all preloads_data_file:dir search;
|
|
|
|
# Allow untrusted apps read / execute access to /vendor/app for there can
|
|
# be pre-installed vendor apps that package a library within themselves.
|
|
# TODO (b/37784178) Consider creating a special type for /vendor/app installed
|
|
# apps.
|
|
allow untrusted_app_all vendor_app_file:dir { open getattr read search };
|
|
allow untrusted_app_all vendor_app_file:file { open getattr read execute };
|
|
allow untrusted_app_all vendor_app_file:lnk_file { open getattr read };
|
|
|
|
# Write app-specific trace data to the Perfetto traced damon. This requires
|
|
# connecting to its producer socket and obtaining a (per-process) tmpfs fd.
|
|
allow untrusted_app_all traced:fd use;
|
|
allow untrusted_app_all traced_tmpfs:file { read write getattr map };
|
|
unix_socket_connect(untrusted_app_all, traced_producer, traced)
|
|
|
|
# allow untrusted apps to use UDP sockets provided by the system server but not
|
|
# modify them other than to connect
|
|
allow untrusted_app_all system_server:udp_socket {
|
|
connect getattr read recvfrom sendto write getopt setopt };
|
|
|
|
# This is allowed for targetSdkVersion <= 25 but disallowed on newer versions.
|
|
dontaudit untrusted_app_all net_dns_prop:file read;
|
|
|
|
# These have been disallowed since Android O.
|
|
# For P, we assume that apps are safely handling the denial.
|
|
dontaudit untrusted_app_all proc_stat:file read;
|
|
dontaudit untrusted_app_all proc_vmstat:file read;
|
|
dontaudit untrusted_app_all proc_uptime:file read;
|
|
|
|
# Allow the allocation and use of ptys
|
|
# Used by: https://play.google.com/store/apps/details?id=jackpal.androidterm
|
|
create_pty(untrusted_app_all)
|
|
|
|
# /proc/net access.
|
|
# TODO(b/9496886) Audit access for removal.
|
|
# VPN apps require access to /proc/net/{tcp,udp} so access will need to be
|
|
# limited through a mechanism other than SELinux.
|
|
r_dir_file(untrusted_app_all, proc_net_type)
|
|
userdebug_or_eng(`
|
|
auditallow untrusted_app_all {
|
|
proc_net_type
|
|
-proc_net_vpn
|
|
}:{ dir file lnk_file } { getattr open read };
|
|
')
|
|
|
|
# Attempts to write to system_data_file is generally a sign
|
|
# that apps are attempting to access encrypted storage before
|
|
# the ACTION_USER_UNLOCKED intent is delivered. Suppress this
|
|
# denial to prevent third party apps from spamming the logs.
|
|
dontaudit untrusted_app_all system_data_file:dir write;
|