[Utopia] [patch] Disable automounting when screen saver is running

[David Zeuthen <david fubar dk>]

Hi,

One of our security dudes at Red Hat mentioned a possible attack vector.

When the screen saver is running, the user may not be around to keep an 
eye on their machine. There are a number of security attacks with a 
specially crafted filesystem that can happen since the automounter 
effectively performs mount, which is a privileged command, and reads the 
directory contents.

This patch applies to both g-v-m 2.15 and 2.17. Suitable for upstream?

Thanks,
David

$ diffstat gnome-volume-manager-2.15.0-check-screensaver.patch
 manager.c |   53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

--- src/manager.c.orig	2006-11-14 15:13:17.000000000 -0500
+++ src/manager.c	2006-11-14 15:30:54.000000000 -0500
@@ -61,6 +61,7 @@
 
 static struct gvm_configuration config;
 static DBusConnection *dbus_connection;
+static DBusConnection *dbus_connection_session;
 static char *gnome_mount = NULL;
 static LibHalContext *hal_ctx;
 
@@ -1716,6 +1717,42 @@
 	return iocharset;
 }
 
+static gboolean
+gvm_is_screensaver_running (gboolean *is_screensaver_running)
+{
+	DBusError error;
+	DBusMessage *msg;
+	DBusMessage *reply;
+	DBusMessageIter iter;
+
+	if (!(msg = dbus_message_new_method_call ("org.gnome.ScreenSaver", 
+						  "/",
+						  "org.gnome.ScreenSaver",
+						  "GetActive"))) {
+		dbg ("gvm_is_screensaver_running: could not create dbus message\n");
+		return FALSE;
+	}
+
+	dbus_error_init (&error);
+	if (!(reply = dbus_connection_send_with_reply_and_block (dbus_connection_session, msg, -1, &error))) {
+		dbg ("gvm_is_screensaver_running: %s\n", error.message);
+		dbus_message_unref (msg);
+		dbus_error_free (&error);
+		return FALSE;
+	}
+
+	dbus_message_iter_init (reply, &iter);
+	if (dbus_message_iter_get_arg_type (&iter) != DBUS_TYPE_BOOLEAN) {
+		dbg ("gvm_is_screensaver_running: Return value is not a bool");
+		dbus_message_unref (msg);
+		dbus_message_unref (reply);
+		return FALSE;
+	}
+	dbus_message_iter_get_basic (&iter, is_screensaver_running);
+	dbus_message_unref (reply);
+	dbus_message_unref (msg);
+	return TRUE;
+}
 
 /*
  * gvm_device_mount - mount the given device.
@@ -1726,6 +1763,14 @@
 gvm_device_mount (const char *udi, gboolean interactive)
 {
 	struct _MountPolicy *policy;
+	gboolean is_screensaver_running;
+
+	if (gvm_is_screensaver_running (&is_screensaver_running)) {
+		if (is_screensaver_running) {
+			dbg ("refusing to mount %s because screensaver is running\n", udi);
+			return FALSE;
+		}
+	}
 	
 	dbg ("mounting %s...\n", udi);
 	
@@ -2728,9 +2773,17 @@
 		dbus_error_free (&error);
 		return FALSE;
 	}
+
+	if (!(dbus_connection_session = dbus_bus_get (DBUS_BUS_SESSION, &error))) {
+		dbg ("could not get session bus: %s\n", error.message);
+		dbus_error_free (&error);
+		return FALSE;
+	}
 	
 	dbus_connection_setup_with_g_main (dbus_connection, NULL);
 	dbus_connection_set_exit_on_disconnect (dbus_connection, FALSE);
+
+	dbus_connection_setup_with_g_main (dbus_connection_session, NULL);
 	
 	dbus_connection_add_filter (dbus_connection, gvm_dbus_filter_function, NULL, NULL);