Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / net / batman-adv / routing.c

diff --git a/kernel/net/batman-adv/routing.c b/kernel/net/batman-adv/routing.c
index 3207667..d8a2f33 100644 (file)
--- a/kernel/net/batman-adv/routing.c
+++ b/kernel/net/batman-adv/routing.c
@@ -104,6 +104,15 @@ static void _batadv_update_route(struct batadv_priv *bat_priv,
                neigh_node = NULL;
 
        spin_lock_bh(&orig_node->neigh_list_lock);
+       /* curr_router used earlier may not be the current orig_ifinfo->router
+        * anymore because it was dereferenced outside of the neigh_list_lock
+        * protected region. After the new best neighbor has replace the current
+        * best neighbor the reference counter needs to decrease. Consequently,
+        * the code needs to ensure the curr_router variable contains a pointer
+        * to the replaced best neighbor.
+        */
+       curr_router = rcu_dereference_protected(orig_ifinfo->router, true);
+
        rcu_assign_pointer(orig_ifinfo->router, neigh_node);
        spin_unlock_bh(&orig_node->neigh_list_lock);
        batadv_orig_ifinfo_free_ref(orig_ifinfo);