@@ -516,76 +516,79 @@ static void batadv_orig_ifinfo_free_rcu(struct rcu_head *rcu)
}
/**
- * batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly free
- * the orig_ifinfo (without rcu callback)
+ * batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly release
+ * the orig_ifinfo
* @orig_ifinfo: the orig_ifinfo object to release
*/
-static void
-batadv_orig_ifinfo_free_ref_now(struct batadv_orig_ifinfo *orig_ifinfo)
+void batadv_orig_ifinfo_free_ref(struct batadv_orig_ifinfo *orig_ifinfo)
{
if (atomic_dec_and_test(&orig_ifinfo->refcount))
- batadv_orig_ifinfo_free_rcu(&orig_ifinfo->rcu);
+ call_rcu(&orig_ifinfo->rcu, batadv_orig_ifinfo_free_rcu);
}
/**
- * batadv_orig_ifinfo_free_ref - decrement the refcounter and possibly free
- * the orig_ifinfo
- * @orig_ifinfo: the orig_ifinfo object to release
+ * batadv_orig_node_free_rcu - free the orig_node
+ * @rcu: rcu pointer of the orig_node
*/
-void batadv_orig_ifinfo_free_ref(struct batadv_orig_ifinfo *orig_ifinfo)
+static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
{
- if (atomic_dec_and_test(&orig_ifinfo->refcount))
- call_rcu(&orig_ifinfo->rcu, batadv_orig_ifinfo_free_rcu);
+ struct batadv_orig_node *orig_node;
+
+ orig_node = container_of(rcu, struct batadv_orig_node, rcu);
+
+ batadv_mcast_purge_orig(orig_node);
+
+ batadv_frag_purge_orig(orig_node, NULL);
+
+ if (orig_node->bat_priv->bat_algo_ops->bat_orig_free)
+ orig_node->bat_priv->bat_algo_ops->bat_orig_free(orig_node);
+
+ kfree(orig_node->tt_buff);
+ kfree(orig_node);
}
-static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
+/**
+ * batadv_orig_node_release - release orig_node from lists and queue for
+ * free after rcu grace period
+ * @orig_node: the orig node to free
+ */
+static void batadv_orig_node_release(struct batadv_orig_node *orig_node)
{
struct hlist_node *node_tmp;
struct batadv_neigh_node *neigh_node;
- struct batadv_orig_node *orig_node;
struct batadv_orig_ifinfo *orig_ifinfo;
- orig_node = container_of(rcu, struct batadv_orig_node, rcu);
-
spin_lock_bh(&orig_node->neigh_list_lock);
/* for all neighbors towards this originator ... */
hlist_for_each_entry_safe(neigh_node, node_tmp,
&orig_node->neigh_list, list) {
hlist_del_rcu(&neigh_node->list);
- batadv_neigh_node_free_ref_now(neigh_node);
+ batadv_neigh_node_free_ref(neigh_node);
}
hlist_for_each_entry_safe(orig_ifinfo, node_tmp,
&orig_node->ifinfo_list, list) {
hlist_del_rcu(&orig_ifinfo->list);
- batadv_orig_ifinfo_free_ref_now(orig_ifinfo);
+ batadv_orig_ifinfo_free_ref(orig_ifinfo);
}
spin_unlock_bh(&orig_node->neigh_list_lock);
- batadv_mcast_purge_orig(orig_node);
-
/* Free nc_nodes */
batadv_nc_purge_orig(orig_node->bat_priv, orig_node, NULL);
- batadv_frag_purge_orig(orig_node, NULL);
-
- if (orig_node->bat_priv->bat_algo_ops->bat_orig_free)
- orig_node->bat_priv->bat_algo_ops->bat_orig_free(orig_node);
-
- kfree(orig_node->tt_buff);
- kfree(orig_node);
+ call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu);
}
/**
* batadv_orig_node_free_ref - decrement the orig node refcounter and possibly
- * schedule an rcu callback for freeing it
+ * release it
* @orig_node: the orig node to free
*/
void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node)
{
if (atomic_dec_and_test(&orig_node->refcount))
- call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu);
+ batadv_orig_node_release(orig_node);
}
/**
This is a note to let you know that I have just added a patch titled batman-adv: Drop immediate batadv_orig_ifinfo free function to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt24. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From 7b4c331eae4658c04986f5cfabb94c2e312948ff Mon Sep 17 00:00:00 2001 From: Sven Eckelmann <sven@narfation.org> Date: Tue, 5 Jan 2016 12:06:21 +0100 Subject: batman-adv: Drop immediate batadv_orig_ifinfo free function commit deed96605f5695cb945e0b3d79429581857a2b9d upstream. It is not allowed to free the memory of an object which is part of a list which is protected by rcu-read-side-critical sections without making sure that no other context is accessing the object anymore. This usually happens by removing the references to this object and then waiting until the rcu grace period is over and no one (allowedly) accesses it anymore. But the _now functions ignore this completely. They free the object directly even when a different context still tries to access it. This has to be avoided and thus these functions must be removed and all functions have to use batadv_orig_ifinfo_free_ref. Fixes: 7351a4822d42 ("batman-adv: split out router from orig_node") Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <a@unstable.cc> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- net/batman-adv/originator.c | 59 ++++++++++++++++++++++++--------------------- 1 file changed, 31 insertions(+), 28 deletions(-)