From 2234f9ff579f9e928d868372f5bd7499e2da7bd1 Mon Sep 17 00:00:00 2001 From: Nick Kralevich Date: Wed, 8 Apr 2015 21:30:48 -0700 Subject: gatekeeperd: neverallow non-system_server binder call The current neverallow rule (compile time assertion) neverallow { domain -gatekeeperd -system_server } gatekeeper_service:service_manager find; asserts that no rule is present which allows processes other than system_server from asking servicemanager for a gatekeeperd token. However, if system_server leaks the token to other processes, it may be possible for those processes to access gatekeeperd directly, bypassing servicemanager. Add a neverallow rule to assert that no process other than system_server are allowed to make binder calls to gatekeeperd. Even if another process was to manage to get a binder token to gatekeeperd, it would be useless. Remove binder_service() from gatekeeperd. The original use of the binder_service() macro was to widely publish a binder service. If this macro is present and the calling process has a gatekeeperd binder token, it's implicitly possible for the following processes to make a binder call to gatekeeperd: * all app processes * dumpstate * system_server * mediaserver * surfaceflinger Removing binder_service revokes this implicit access. Add explicit access for system_server to make binder calls to gatekeeperd. Add explicit access for gatekeeperd to make calls to keystore. This was implicitly granted via binder_service() before, but now needs to be explicit. Change-Id: I23c1573d04ab670a42660d5922b39eecf4265b66 --- system_server.te | 1 + 1 file changed, 1 insertion(+) (limited to 'system_server.te') diff --git a/system_server.te b/system_server.te index ac7a7c7..d8e5978 100644 --- a/system_server.te +++ b/system_server.te @@ -122,6 +122,7 @@ allow system_server surfaceflinger:unix_stream_socket { read write setopt }; # Perform Binder IPC. binder_use(system_server) binder_call(system_server, binderservicedomain) +binder_call(system_server, gatekeeperd) binder_call(system_server, appdomain) binder_call(system_server, dumpstate) binder_service(system_server) -- cgit v1.2.3