Start partitioning off privapp_data_file from app_data_file
Currently, both untrusted apps and priv-apps use the SELinux file label
"app_data_file" for files in their /data/data directory. This is
problematic, as we really want different rules for such files. For
example, we may want to allow untrusted apps to load executable code
from priv-app directories, but disallow untrusted apps from loading
executable code from their own home directories.
This change adds a new file type "privapp_data_file". For compatibility,
we adjust the policy to support access privapp_data_files almost
everywhere we were previously granting access to app_data_files
(adbd and run-as being exceptions). Additional future tightening is
possible here by removing some of these newly added rules.
This label will start getting used in a followup change to
system/sepolicy/private/seapp_contexts, similar to:
-user=_app isPrivApp=true domain=priv_app type=app_data_file levelFrom=user
+user=_app isPrivApp=true domain=priv_app type=privapp_data_file levelFrom=user
For now, this newly introduced label has no usage, so this change
is essentially a no-op.
Test: Factory reset and boot - no problems on fresh install.
Test: Upgrade to new version and test. No compatibility problems on
filesystem upgrade.
Change-Id: I9618b7d91d1c2bcb5837cdabc949f0cf741a2837
diff --git a/private/ephemeral_app.te b/private/ephemeral_app.te
index 75a6317..f28d28f 100644
--- a/private/ephemeral_app.te
+++ b/private/ephemeral_app.te
@@ -21,7 +21,7 @@
# Some apps ship with shared libraries and binaries that they write out
# to their sandbox directory and then execute.
-allow ephemeral_app app_data_file:file {r_file_perms execute};
+allow ephemeral_app { app_data_file privapp_data_file }:file {r_file_perms execute};
# services
allow ephemeral_app audioserver_service:service_manager find;
@@ -50,7 +50,7 @@
### neverallow rules
###
-neverallow ephemeral_app app_data_file:file execute_no_trans;
+neverallow ephemeral_app { app_data_file privapp_data_file }:file execute_no_trans;
# Receive or send uevent messages.
neverallow ephemeral_app domain:netlink_kobject_uevent_socket *;