@@ -150,42 +150,28 @@ err:
}
/**
- * batadv_neigh_ifinfo_free_rcu - free the neigh_ifinfo object
- * @rcu: rcu pointer of the neigh_ifinfo object
- */
-static void batadv_neigh_ifinfo_free_rcu(struct rcu_head *rcu)
-{
- struct batadv_neigh_ifinfo *neigh_ifinfo;
-
- neigh_ifinfo = container_of(rcu, struct batadv_neigh_ifinfo, rcu);
-
- if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT)
- batadv_hardif_free_ref_now(neigh_ifinfo->if_outgoing);
-
- kfree(neigh_ifinfo);
-}
-
-/**
- * batadv_neigh_ifinfo_free_now - decrement the refcounter and possibly free
- * the neigh_ifinfo (without rcu callback)
+ * batadv_neigh_ifinfo_release - release neigh_ifinfo from lists and queue for
+ * free after rcu grace period
* @neigh_ifinfo: the neigh_ifinfo object to release
*/
static void
-batadv_neigh_ifinfo_free_ref_now(struct batadv_neigh_ifinfo *neigh_ifinfo)
+batadv_neigh_ifinfo_release(struct batadv_neigh_ifinfo *neigh_ifinfo)
{
- if (atomic_dec_and_test(&neigh_ifinfo->refcount))
- batadv_neigh_ifinfo_free_rcu(&neigh_ifinfo->rcu);
+ if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT)
+ batadv_hardif_free_ref(neigh_ifinfo->if_outgoing);
+
+ kfree_rcu(neigh_ifinfo, rcu);
}
/**
- * batadv_neigh_ifinfo_free_ref - decrement the refcounter and possibly free
+ * batadv_neigh_ifinfo_free_ref - decrement the refcounter and possibly release
* the neigh_ifinfo
* @neigh_ifinfo: the neigh_ifinfo object to release
*/
void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo)
{
if (atomic_dec_and_test(&neigh_ifinfo->refcount))
- call_rcu(&neigh_ifinfo->rcu, batadv_neigh_ifinfo_free_rcu);
+ batadv_neigh_ifinfo_release(neigh_ifinfo);
}
/**
@@ -202,7 +188,7 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu)
hlist_for_each_entry_safe(neigh_ifinfo, node_tmp,
&neigh_node->ifinfo_list, list) {
- batadv_neigh_ifinfo_free_ref_now(neigh_ifinfo);
+ batadv_neigh_ifinfo_free_ref(neigh_ifinfo);
}
batadv_hardif_free_ref_now(neigh_node->if_incoming);
This is a note to let you know that I have just added a patch titled batman-adv: Drop immediate neigh_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 a03f20f4e7682751dea2d192306c4fb995432468 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann <sven@narfation.org> Date: Tue, 5 Jan 2016 12:06:24 +0100 Subject: batman-adv: Drop immediate neigh_ifinfo free function commit ae3e1e36e3cb6c686a7a2725af20ca86aa46d62a 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_neigh_ifinfo_free_ref. Fixes: 89652331c00f ("batman-adv: split tq information in neigh_node struct") 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 | 34 ++++++++++------------------------ 1 file changed, 10 insertions(+), 24 deletions(-)