DO NOT MERGE Fake 29.0 sepolicy prebuilts
I took current AOSP policy as base, then removed sepolicy so that the
set of type and attributes was a subset of types and attributes in Q
sepolicy, with exception of those that have not yet been cleand up in
current AOSP:
mediaswcodec_server
netd_socket
mediaextractor_update_service
thermalserviced
thermalserviced_exec
Bug: 133196056
Test: n/a
Change-Id: I2cbe749777684146114c89e1e6fc3f07400c0ae5
diff --git a/prebuilts/api/29.0/private/app_neverallows.te b/prebuilts/api/29.0/private/app_neverallows.te
new file mode 100644
index 0000000..3a5923e
--- /dev/null
+++ b/prebuilts/api/29.0/private/app_neverallows.te
@@ -0,0 +1,293 @@
+###
+### neverallow rules for untrusted app domains
+###
+
+define(`all_untrusted_apps',`{
+ ephemeral_app
+ isolated_app
+ mediaprovider
+ untrusted_app
+ untrusted_app_25
+ untrusted_app_27
+ untrusted_app_all
+}')
+# Receive or send uevent messages.
+neverallow all_untrusted_apps domain:netlink_kobject_uevent_socket *;
+
+# Receive or send generic netlink messages
+neverallow all_untrusted_apps domain:netlink_socket *;
+
+# Too much leaky information in debugfs. It's a security
+# best practice to ensure these files aren't readable.
+neverallow all_untrusted_apps { debugfs_type -debugfs_kcov }:file read;
+neverallow {all_untrusted_apps userdebug_or_eng(`-domain')} debugfs_type:{ file lnk_file } read;
+
+# Do not allow untrusted apps to register services.
+# Only trusted components of Android should be registering
+# services.
+neverallow all_untrusted_apps service_manager_type:service_manager add;
+
+# Do not allow untrusted apps to use VendorBinder
+neverallow all_untrusted_apps vndbinder_device:chr_file *;
+neverallow all_untrusted_apps vndservice_manager_type:service_manager *;
+
+# Do not allow untrusted apps to connect to the property service
+# or set properties. b/10243159
+neverallow { all_untrusted_apps -mediaprovider } property_socket:sock_file write;
+neverallow { all_untrusted_apps -mediaprovider } init:unix_stream_socket connectto;
+neverallow { all_untrusted_apps -mediaprovider } property_type:property_service set;
+
+# net.dns properties are not a public API. Temporarily exempt pre-Oreo apps,
+# but otherwise disallow untrusted apps from reading this property.
+neverallow { all_untrusted_apps -untrusted_app_25 } net_dns_prop:file read;
+
+# Shared libraries created by trusted components within an app home
+# directory can be dlopen()ed. To maintain the W^X property, these files
+# must never be writable to the app.
+neverallow all_untrusted_apps app_exec_data_file:file
+ { append create link relabelfrom relabelto rename setattr write };
+
+# Block calling execve() on files in an apps home directory.
+# This is a W^X violation (loading executable code from a writable
+# home directory). For compatibility, allow for targetApi <= 28.
+# b/112357170
+neverallow {
+ all_untrusted_apps
+ -untrusted_app_25
+ -untrusted_app_27
+ -runas_app
+} { app_data_file privapp_data_file }:file execute_no_trans;
+
+# Do not allow untrusted apps to invoke dex2oat. This was historically required
+# by ART for compiling secondary dex files but has been removed in Q.
+# Exempt legacy apps (targetApi<=28) for compatibility.
+neverallow {
+ all_untrusted_apps
+ -untrusted_app_25
+ -untrusted_app_27
+} dex2oat_exec:file no_x_file_perms;
+
+# Do not allow untrusted apps 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 an untrusted app is allowed fork permission to itself.
+neverallow all_untrusted_apps mlstrustedsubject:process fork;
+
+# Do not allow untrusted apps to hard link to any files.
+# In particular, if an 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 apps never have this
+# capability.
+neverallow all_untrusted_apps file_type:file link;
+
+# Do not allow untrusted apps to access network MAC address file
+neverallow all_untrusted_apps sysfs_mac_address:file no_rw_file_perms;
+
+# Do not allow any write access to files in /sys
+neverallow all_untrusted_apps sysfs_type:file { no_w_file_perms no_x_file_perms };
+
+# Apps may never access the default sysfs label.
+neverallow all_untrusted_apps sysfs: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 all_untrusted_apps domain:{ icmp_socket rawip_socket tcp_socket udp_socket } ioctl priv_sock_ioctls;
+neverallow all_untrusted_apps *:{ netlink_route_socket netlink_selinux_socket } ioctl;
+neverallow all_untrusted_apps *:{
+ socket netlink_socket packet_socket key_socket appletalk_socket
+ netlink_tcpdiag_socket netlink_nflog_socket
+ netlink_xfrm_socket netlink_audit_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 sctp_socket
+ ax25_socket ipx_socket netrom_socket atmpvc_socket x25_socket rose_socket decnet_socket
+ atmsvc_socket rds_socket irda_socket pppox_socket llc_socket can_socket tipc_socket
+ bluetooth_socket iucv_socket rxrpc_socket isdn_socket phonet_socket ieee802154_socket caif_socket
+ alg_socket nfc_socket vsock_socket kcm_socket qipcrtr_socket smc_socket xdp_socket
+} *;
+
+# Do not allow untrusted apps access to /cache
+neverallow { all_untrusted_apps -mediaprovider } { cache_file cache_recovery_file }:dir ~{ r_dir_perms };
+neverallow { all_untrusted_apps -mediaprovider } { cache_file cache_recovery_file }:file ~{ read getattr };
+
+# Do not allow untrusted apps 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 { all_untrusted_apps -mediaprovider } {
+ fs_type
+ -sdcard_type
+ file_type
+ -app_data_file # The apps sandbox itself
+ -privapp_data_file
+ -app_exec_data_file # stored within the app sandbox directory
+ -media_rw_data_file # Internal storage. Known that apps can
+ # leave artfacts here after uninstall.
+ -user_profile_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 };
+
+# No untrusted component should be touching /dev/fuse
+neverallow all_untrusted_apps fuse_device:chr_file *;
+
+# Do not allow untrusted apps to directly open the tun_device
+neverallow all_untrusted_apps tun_device:chr_file open;
+# The tun_device ioctls below are not allowed, to prove equivalence
+# to the kernel patch at
+# https://android.googlesource.com/kernel/common/+/11cee2be0c2062ba88f04eb51196506f870a3b5d%5E%21
+neverallowxperm all_untrusted_apps tun_device:chr_file ioctl {
+ SIOCGIFHWADDR
+ SIOCSIFHWADDR
+ TUNATTACHFILTER
+ TUNDETACHFILTER
+ TUNGETFEATURES
+ TUNGETFILTER
+ TUNGETSNDBUF
+ TUNGETVNETHDRSZ
+ TUNSETDEBUG
+ TUNSETGROUP
+ TUNSETIFF
+ TUNSETLINK
+ TUNSETNOCSUM
+ TUNSETOFFLOAD
+ TUNSETOWNER
+ TUNSETPERSIST
+ TUNSETQUEUE
+ TUNSETSNDBUF
+ TUNSETTXFILTER
+ TUNSETVNETHDRSZ
+};
+
+# Only allow appending to /data/anr/traces.txt (b/27853304, b/18340553)
+neverallow all_untrusted_apps anr_data_file:file ~{ open append };
+neverallow all_untrusted_apps anr_data_file:dir ~search;
+
+# Avoid reads from generically labeled /proc files
+# Create a more specific label if needed
+neverallow all_untrusted_apps {
+ proc
+ proc_asound
+ proc_filesystems
+ proc_kmsg
+ proc_loadavg
+ proc_mounts
+ proc_pagetypeinfo
+ proc_slabinfo
+ proc_stat
+ proc_swaps
+ proc_uptime
+ proc_version
+ proc_vmallocinfo
+ proc_vmstat
+}:file { no_rw_file_perms no_x_file_perms };
+
+# Avoid all access to kernel configuration
+neverallow all_untrusted_apps config_gz:file { no_rw_file_perms no_x_file_perms };
+
+# Do not allow untrusted apps access to preloads data files
+neverallow all_untrusted_apps preloads_data_file:file no_rw_file_perms;
+
+# Locking of files on /system could lead to denial of service attacks
+# against privileged system components
+neverallow all_untrusted_apps system_file:file lock;
+
+# Do not permit untrusted apps to perform actions on HwBinder service_manager
+# other than find actions for services listed below
+neverallow all_untrusted_apps *:hwservice_manager ~find;
+
+# Do not permit access from apps which host arbitrary code to HwBinder services,
+# except those considered sufficiently safe for access from such apps.
+# The two main reasons for this are:
+# 1. HwBinder servers do not perform client authentication because HIDL
+# currently does not expose caller UID information and, even if it did, many
+# HwBinder services either operate at a level below that of apps (e.g., HALs)
+# or must not rely on app identity for authorization. Thus, to be safe, the
+# default assumption is that every HwBinder service treats all its clients as
+# equally authorized to perform operations offered by the service.
+# 2. HAL servers (a subset of HwBinder services) contain code with higher
+# incidence rate of security issues than system/core components and have
+# access to lower layes of the stack (all the way down to hardware) thus
+# increasing opportunities for bypassing the Android security model.
+#
+# Safe services include:
+# - same process services: because they by definition run in the process
+# of the client and thus have the same access as the client domain in which
+# the process runs
+# - coredomain_hwservice: are considered safe because they do not pose risks
+# associated with reason #2 above.
+# - hal_configstore_ISurfaceFlingerConfigs: becuase it has specifically been
+# designed for use by any domain.
+# - hal_graphics_allocator_hwservice: because these operations are also offered
+# by surfaceflinger Binder service, which apps are permitted to access
+# - hal_omx_hwservice: because this is a HwBinder version of the mediacodec
+# Binder service which apps were permitted to access.
+# - hal_codec2_hwservice: because this is a newer version of hal_omx_hwservice.
+neverallow all_untrusted_apps {
+ hwservice_manager_type
+ -fwk_bufferhub_hwservice
+ -hal_cas_hwservice
+ -hal_codec2_hwservice
+ -hal_configstore_ISurfaceFlingerConfigs
+ -hal_graphics_allocator_hwservice
+ -hal_graphics_mapper_hwservice
+ -hal_neuralnetworks_hwservice
+ -hal_omx_hwservice
+ -hal_renderscript_hwservice
+ -hidl_allocator_hwservice
+ -hidl_manager_hwservice
+ -hidl_memory_hwservice
+ -hidl_token_hwservice
+ -untrusted_app_visible_hwservice_violators
+}:hwservice_manager find;
+
+# SELinux is not an API for untrusted apps to use
+neverallow all_untrusted_apps selinuxfs:file no_rw_file_perms;
+
+# Restrict *Binder access from apps to HAL domains. We can only do this on full
+# Treble devices where *Binder communications between apps and HALs are tightly
+# restricted.
+full_treble_only(`
+ neverallow all_untrusted_apps {
+ halserverdomain
+ -coredomain
+ -hal_configstore_server
+ -hal_graphics_allocator_server
+ -hal_cas_server
+ -hal_neuralnetworks_server
+ -hal_omx_server
+ -binder_in_vendor_violators # TODO(b/35870313): Remove once all violations are gone
+ -untrusted_app_visible_halserver_violators
+ }:binder { call transfer };
+')
+
+# Untrusted apps are not allowed to find mediaextractor update service.
+
+# 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
+# This will go away in a future Android release
+neverallow { all_untrusted_apps -untrusted_app_25 } proc_tty_drivers:file r_file_perms;
+neverallow all_untrusted_apps proc_tty_drivers:file ~r_file_perms;
+
+# Untrusted apps are not allowed to use cgroups.
+neverallow all_untrusted_apps cgroup:file *;
+
+# Untrusted apps targetting >= Q are not allowed to open /dev/ashmem directly.
+# They must use ASharedMemory NDK API instead.
+neverallow {
+ all_untrusted_apps
+ -ephemeral_app
+ -untrusted_app_25
+ -untrusted_app_27
+} ashmem_device:chr_file open;