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/untrusted_app_all.te b/private/untrusted_app_all.te
index 07d9d4d..65be583 100644
--- a/private/untrusted_app_all.te
+++ b/private/untrusted_app_all.te
@@ -23,7 +23,7 @@
# Some apps ship with shared libraries and binaries that they write out
# to their sandbox directory and then execute.
-allow untrusted_app_all app_data_file:file { rx_file_perms };
+allow untrusted_app_all { app_data_file privapp_data_file }:file { rx_file_perms };
# ASEC
allow untrusted_app_all asec_apk_file:file r_file_perms;