[linux-next] LinuxNextTracking branch, master, updated. next-20150810

batman at open-mesh.org batman at open-mesh.org
Tue Aug 11 00:15:39 CEST 2015


The following commit has been merged in the master branch:
commit ef72706a0543d0c3a5ab29bd6378fdfb368118d9
Author: Marek Lindner <mareklindner at neomailbox.ch>
Date:   Wed Jun 17 20:01:36 2015 +0800

    batman-adv: protect tt_local_entry from concurrent delete events
    
    The tt_local_entry deletion performed in batadv_tt_local_remove() was neither
    protecting against simultaneous deletes nor checking whether the element was
    still part of the list before calling hlist_del_rcu().
    
    Replacing the hlist_del_rcu() call with batadv_hash_remove() provides adequate
    protection via hash spinlocks as well as an is-element-still-in-hash check to
    avoid 'blind' hash removal.
    
    Fixes: 068ee6e204e1 ("batman-adv: roaming handling mechanism redesign")
    Reported-by: alfonsname at web.de
    Signed-off-by: Marek Lindner <mareklindner at neomailbox.ch>
    Signed-off-by: Antonio Quartulli <antonio at meshcoding.com>

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 38b83c5..5e953297 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1037,6 +1037,7 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv,
 	struct batadv_tt_local_entry *tt_local_entry;
 	uint16_t flags, curr_flags = BATADV_NO_FLAGS;
 	struct batadv_softif_vlan *vlan;
+	void *tt_entry_exists;
 
 	tt_local_entry = batadv_tt_local_hash_find(bat_priv, addr, vid);
 	if (!tt_local_entry)
@@ -1064,7 +1065,15 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv,
 	 * immediately purge it
 	 */
 	batadv_tt_local_event(bat_priv, tt_local_entry, BATADV_TT_CLIENT_DEL);
-	hlist_del_rcu(&tt_local_entry->common.hash_entry);
+
+	tt_entry_exists = batadv_hash_remove(bat_priv->tt.local_hash,
+					     batadv_compare_tt,
+					     batadv_choose_tt,
+					     &tt_local_entry->common);
+	if (!tt_entry_exists)
+		goto out;
+
+	/* extra call to free the local tt entry */
 	batadv_tt_local_entry_free_ref(tt_local_entry);
 
 	/* decrease the reference held for this vlan */

-- 
LinuxNextTracking


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