[gvfs/gnome-3-22] dnssd: Free resolvers also on client failure

[Ondrej Holy <oholy src gnome org>]

commit df5c7aa8894d97d1a25c380276de76537017111a
Author: Ondrej Holy <oholy redhat com>
Date:   Thu Oct 13 12:34:14 2016 +0200

    dnssd: Free resolvers also on client failure
    
    Resolvers are not currently removed on client failure. It might
    potentialy lead to some use-after-free crashes. Remove resolver
    objects also on client failures.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=631023

 daemon/gvfsbackenddnssd.c |   13 +++++++++++--
 1 files changed, 11 insertions(+), 2 deletions(-)
---
diff --git a/daemon/gvfsbackenddnssd.c b/daemon/gvfsbackenddnssd.c
index 31bf54c..dde7dff 100644
--- a/daemon/gvfsbackenddnssd.c
+++ b/daemon/gvfsbackenddnssd.c
@@ -140,6 +140,7 @@ G_DEFINE_TYPE (GVfsBackendDnsSd, g_vfs_backend_dns_sd, G_VFS_TYPE_BACKEND)
 
 static void add_browsers (GVfsBackendDnsSd *backend);
 static void remove_browsers (GVfsBackendDnsSd *backend);
+static void remove_resolvers (GVfsBackendDnsSd *backend);
 static AvahiClient *get_global_avahi_client (void);
 
 /* Callback for state changes on the Client */
@@ -157,7 +158,8 @@ avahi_client_callback (AvahiClient *client, AvahiClientState state, void *userda
        {
          /* Remove the service browsers from the handles */
          g_list_foreach (dnssd_backends, (GFunc)remove_browsers, NULL);
-         
+         g_list_foreach (dnssd_backends, (GFunc)remove_resolvers, NULL);
+
          /* Destroy old client */
          avahi_client_free (client);
          global_client = NULL;
@@ -702,6 +704,13 @@ remove_browsers (GVfsBackendDnsSd *backend)
   backend->browsers = NULL;
 }
 
+static void
+remove_resolvers (GVfsBackendDnsSd *backend)
+{
+  g_list_free_full (backend->resolvers, (GDestroyNotify)avahi_service_resolver_free);
+  backend->resolvers = NULL;
+}
+
 static gboolean
 try_mount (GVfsBackend *backend,
            GVfsJobMount *job,
@@ -802,7 +811,7 @@ g_vfs_backend_dns_sd_finalize (GObject *object)
   dnssd_backends = g_list_remove (dnssd_backends, backend);
 
   remove_browsers (backend);
-  g_list_free_full (backend->resolvers, (GDestroyNotify)avahi_service_resolver_free);
+  remove_resolvers (backend);
 
   if (backend->mount_spec)
     g_mount_spec_unref (backend->mount_spec);