From e56f126071882b88f3d6ef53cb611794d12e5e14 Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Tue, 25 May 2021 21:50:41 +0200
Subject: [PATCH] libnm: fix error handling in NMVpnPluginOld's
 _connect_generic()

Also Coverity found that something is wrong here:

   Error: FORWARD_NULL (CWE-476): [#def361]
   NetworkManager-1.31.5/src/libnm-client-impl/nm-vpn-plugin-old.c:441: var_compare_op: Comparing "connection" to null implies that "connection" might be null.
   NetworkManager-1.31.5/src/libnm-client-impl/nm-vpn-plugin-old.c:489: var_deref_model: Passing null pointer "connection" to "g_object_unref", which dereferences it.
   #  487|       }
   #  488|
   #  489|->     g_object_unref(connection);
   #  490|   }
   #  491|

Fixes: 6793a32a8c54 ('libnm: port to GDBus')
---
 src/libnm-client-impl/nm-vpn-plugin-old.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/libnm-client-impl/nm-vpn-plugin-old.c b/src/libnm-client-impl/nm-vpn-plugin-old.c
index be4e1cf292..7430622b90 100644
--- a/src/libnm-client-impl/nm-vpn-plugin-old.c
+++ b/src/libnm-client-impl/nm-vpn-plugin-old.c
@@ -420,12 +420,12 @@ _connect_generic(NMVpnPluginOld *       plugin,
                  GVariant *             properties,
                  GVariant *             details)
 {
-    NMVpnPluginOldPrivate *priv      = NM_VPN_PLUGIN_OLD_GET_PRIVATE(plugin);
-    NMVpnPluginOldClass *  vpn_class = NM_VPN_PLUGIN_OLD_GET_CLASS(plugin);
-    NMConnection *         connection;
-    gboolean               success           = FALSE;
-    GError *               error             = NULL;
-    guint                  fail_stop_timeout = 0;
+    NMVpnPluginOldPrivate *priv                     = NM_VPN_PLUGIN_OLD_GET_PRIVATE(plugin);
+    NMVpnPluginOldClass *  vpn_class                = NM_VPN_PLUGIN_OLD_GET_CLASS(plugin);
+    gs_unref_object NMConnection *connection        = NULL;
+    gboolean                      success           = FALSE;
+    GError *                      error             = NULL;
+    guint                         fail_stop_timeout = 0;
 
     if (priv->state != NM_VPN_SERVICE_STATE_STOPPED && priv->state != NM_VPN_SERVICE_STATE_INIT) {
         g_dbus_method_invocation_return_error(context,
@@ -445,6 +445,7 @@ _connect_generic(NMVpnPluginOld *       plugin,
                                               "Invalid connection: %s",
                                               error->message);
         g_clear_error(&error);
+        return;
     }
 
     priv->interactive = FALSE;
@@ -485,8 +486,6 @@ _connect_generic(NMVpnPluginOld *       plugin,
          */
         schedule_fail_stop(plugin, fail_stop_timeout);
     }
-
-    g_object_unref(connection);
 }
 
 static void