Implement permission check for VMs that request tee_services
VM can request to access SMC services via new tee_services field in
RawConfig and AppConfig.
The policy on what VMs can access what SMC services is defined in the
sepolicy by specifying allow rules for the processes that starts VMs
("VM owner" processes), e.g.:
```
allow shell test_pkvm_tee_service:tee_service use;
```
The virtmngr will use getprevcon to get the secontext of the VM owner,
and then use libselinux to lookup the mapping from the tee_services
to selinux labels. It then will use selinux_check_permission to check if
the VM owner is allowed the access.
Bug: 360102915
Test: atest MicrodroidTests
Test: AVF presubmit
Test: atest virtualizationmanager_device_test
Test: adb shell /apex/com.android.virt/bin/vm run-microdroid \
--protected \
--tee-services test_pkvm_tee_service
Change-Id: I4a94df5b897cd6a256d0958c73f57afa3d911b4f
diff --git a/android/virtmgr/src/aidl.rs b/android/virtmgr/src/aidl.rs
index cc7cf7c..e63af24 100644
--- a/android/virtmgr/src/aidl.rs
+++ b/android/virtmgr/src/aidl.rs
@@ -21,7 +21,7 @@
use crate::debug_config::DebugConfig;
use crate::dt_overlay::{create_device_tree_overlay, VM_DT_OVERLAY_MAX_SIZE, VM_DT_OVERLAY_PATH};
use crate::payload::{add_microdroid_payload_images, add_microdroid_system_images, add_microdroid_vendor_image};
-use crate::selinux::{getfilecon, getprevcon, SeContext};
+use crate::selinux::{check_tee_service_permission, getfilecon, getprevcon, SeContext};
use android_os_permissions_aidl::aidl::android::os::IPermissionController;
use android_system_virtualizationcommon::aidl::android::system::virtualizationcommon::{
Certificate::Certificate,
@@ -561,6 +561,10 @@
let config = config.as_ref();
*is_protected = config.protectedVm;
+ check_tee_service_permission(&caller_secontext, &config.teeServices)
+ .with_log()
+ .or_binder_exception(ExceptionCode::SECURITY)?;
+
// Check if partition images are labeled incorrectly. This is to prevent random images
// which are not protected by the Android Verified Boot (e.g. bits downloaded by apps) from
// being loaded in a pVM. This applies to everything but the instance image in the raw