1# only HALs responsible for network hardware should have privileged 2# network capabilities 3neverallow { 4 halserverdomain 5 -hal_bluetooth_server 6 -hal_wifi_server 7 -hal_wifi_hostapd_server 8 -hal_wifi_supplicant_server 9 -hal_telephony_server 10} self:global_capability_class_set { net_admin net_raw }; 11 12# Unless a HAL's job is to communicate over the network, or control network 13# hardware, it should not be using network sockets. 14# NOTE: HALs for automotive devices have an exemption from this rule because in 15# a car it is common to have external modules and HALs need to communicate to 16# those modules using network. Using this exemption for non-automotive builds 17# will result in CTS failure. 18neverallow { 19 halserverdomain 20 -hal_automotive_socket_exemption 21 -hal_tetheroffload_server 22 -hal_wifi_server 23 -hal_wifi_hostapd_server 24 -hal_wifi_supplicant_server 25 -hal_telephony_server 26} domain:{ tcp_socket udp_socket rawip_socket } *; 27 28### 29# HALs are defined as an attribute and so a given domain could hypothetically 30# have multiple HALs in it (or even all of them) with the subsequent policy of 31# the domain comprised of the union of all the HALs. 32# 33# This is a problem because 34# 1) Security sensitive components should only be accessed by specific HALs. 35# 2) hwbinder_call and the restrictions it provides cannot be reasoned about in 36# the platform. 37# 3) The platform cannot reason about defense in depth if there are 38# monolithic domains etc. 39# 40# As an example, hal_keymaster and hal_gatekeeper can access the TEE and while 41# its OK for them to share a process its not OK with them to share processes 42# with other hals. 43# 44# The following neverallow rules, in conjuntion with CTS tests, assert that 45# these security principles are adhered to. 46# 47# Do not allow a hal to exec another process without a domain transition. 48# TODO remove exemptions. 49neverallow { 50 halserverdomain 51 -hal_dumpstate_server 52 -hal_telephony_server 53} { file_type fs_type }:file execute_no_trans; 54# Do not allow a process other than init to transition into a HAL domain. 55neverallow { domain -init } halserverdomain:process transition; 56# Only allow transitioning to a domain by running its executable. Do not 57# allow transitioning into a HAL domain by use of seclabel in an 58# init.*.rc script. 59neverallow * halserverdomain:process dyntransition; 60