Add neverallow rules around who can mount/unmount /apex
Test: m
Bug: 188002184
Change-Id: I8f46896edbee7b68df6f1e3008ff4141df164e4c
diff --git a/private/apexd.te b/private/apexd.te
index 862bab9..48fbcb8 100644
--- a/private/apexd.te
+++ b/private/apexd.te
@@ -187,6 +187,13 @@
# only apexd can write apex-info-list.xml
neverallow { domain -apexd } apex_info_file:file no_w_file_perms;
+# Only apexd and init should be allowed to manage /apex mounts
+# A note on otapreopt_chroot. It used to mount APEXes during postainstall stage of A/B OTAs,
+# but starting from S it just calls into apexd to prepare /apex for otapreoprt. Once the sepolicies
+# around otapreopt_chroot are cleaned up we should be able to remove it from the lists below.
+neverallow { domain -apexd -init -otapreopt_chroot } apex_mnt_dir:filesystem { mount unmount };
+neverallow { domain -apexd -init -otapreopt_chroot } apex_mnt_dir:dir { mounton };
+
# Allow for use in postinstall
allow apexd otapreopt_chroot:fd use;
allow apexd postinstall_apex_mnt_dir:dir { create_dir_perms mounton };