platform_system_sepolicy/public/hal_neverallows.te
Pavel Maltsev 4cafae77a4 Allow to use sockets from hal server for auto
Add an exemption to neverallow rule to use sockets from HAL servers only
for automotive build

Bug: 78901167
Test: assign this attribute to hal_vehicle_default and try to open
socket from HAL implementation
Test: verify that new CTS test will fail for non-automotive build with
this attribute buing used
Test: make cts && cts-tradefed run singleCommand cts --skip-device-info
 --skip-preconditions --abi arm64-v8a --module CtsSecurityHostTestCases
 -t android.security.cts.SELinuxHostTest

Change-Id: I27976443dad4fc5b7425c089512cac65bb54d6d9
2018-05-14 14:36:19 -07:00

59 lines
2.3 KiB
Text

# only HALs responsible for network hardware should have privileged
# network capabilities
neverallow {
halserverdomain
-hal_bluetooth_server
-hal_wifi_server
-hal_wifi_hostapd_server
-hal_wifi_supplicant_server
-hal_telephony_server
} self:global_capability_class_set { net_admin net_raw };
# Unless a HAL's job is to communicate over the network, or control network
# hardware, it should not be using network sockets.
# NOTE: HALs for automotive devices have an exemption from this rule because in
# a car it is common to have external modules and HALs need to communicate to
# those modules using network. Using this exemption for non-automotive builds
# will result in CTS failure.
neverallow {
halserverdomain
-hal_automotive_socket_exemption
-hal_tetheroffload_server
-hal_wifi_server
-hal_wifi_hostapd_server
-hal_wifi_supplicant_server
-hal_telephony_server
} domain:{ tcp_socket udp_socket rawip_socket } *;
###
# HALs are defined as an attribute and so a given domain could hypothetically
# have multiple HALs in it (or even all of them) with the subsequent policy of
# the domain comprised of the union of all the HALs.
#
# This is a problem because
# 1) Security sensitive components should only be accessed by specific HALs.
# 2) hwbinder_call and the restrictions it provides cannot be reasoned about in
# the platform.
# 3) The platform cannot reason about defense in depth if there are
# monolithic domains etc.
#
# As an example, hal_keymaster and hal_gatekeeper can access the TEE and while
# its OK for them to share a process its not OK with them to share processes
# with other hals.
#
# The following neverallow rules, in conjuntion with CTS tests, assert that
# these security principles are adhered to.
#
# Do not allow a hal to exec another process without a domain transition.
# TODO remove exemptions.
neverallow {
halserverdomain
-hal_dumpstate_server
-hal_telephony_server
} { file_type fs_type }:file execute_no_trans;
# Do not allow a process other than init to transition into a HAL domain.
neverallow { domain -init } halserverdomain:process transition;
# Only allow transitioning to a domain by running its executable. Do not
# allow transitioning into a HAL domain by use of seclabel in an
# init.*.rc script.
neverallow * halserverdomain:process dyntransition;