Ignore the denial due to vendor_misc_writer reading DT fstab.
This CL addresses the following denial, when vendor_misc_writer tries to
read DT fstab (i.e. device tree fstab) for /misc entry.
avc: denied { search } for comm="misc_writer" name="android" dev="sysfs" ino=17456 scontext=u:r:vendor_misc_writer:s0 tcontext=u:object_r:sysfs_dt_firmware_android:s0 tclass=dir
DT fstab was used for devices shipped prior to Q, for early-mounting
partitions (e.g. /system, /vendor, /product), which has been disallowed
for Q launch devices. vendor_misc_writer is a new module added since Q,
so it doesn't need to worry about the legacy code path; in practice
there's no benefit of putting /misc entry into DT fstab either.
Bug: 134122603
Test: Build and flash taimen with the change that enables
vendor_misc_writer. Check that it no longer gives the above denial
during boot.
Change-Id: Id2fb206706f7cd19a4cde2701e4155bfc03f01b4
diff --git a/public/vendor_misc_writer.te b/public/vendor_misc_writer.te
index 7093fec..dee9941 100644
--- a/public/vendor_misc_writer.te
+++ b/public/vendor_misc_writer.te
@@ -6,6 +6,8 @@
allow vendor_misc_writer misc_block_device:blk_file w_file_perms;
allow vendor_misc_writer block_device:dir r_dir_perms;
-# Silence the denial when calling libfstab's ReadDefaultFstab.
+# Silence the denial when calling libfstab's ReadDefaultFstab, which tries to
+# load DT fstab.
dontaudit vendor_misc_writer proc_cmdline:file read;
dontaudit vendor_misc_writer metadata_file:dir search;
+dontaudit vendor_misc_writer sysfs_dt_firmware_android:dir search;