diff --git a/private/isolated_app.te b/private/isolated_app.te
index 951a0df..30253af 100644
--- a/private/isolated_app.te
+++ b/private/isolated_app.te
@@ -103,3 +103,11 @@
 
 # Restrict the webview_zygote control socket.
 neverallow isolated_app webview_zygote_socket:sock_file write;
+
+# Limit the /sys files which isolated_app can access. This is important
+# for controlling isolated_app attack surface.
+neverallow isolated_app {
+  sysfs_type
+  -sysfs_devices_system_cpu
+  -sysfs_usb # TODO: check with audio team if needed for isolated_app (b/28417852)
+}:file no_rw_file_perms;