Repository : ssh://git@open-mesh.org/batman-adv
On branch : maint
commit af912d77181f252e6fdd324592d006e30bc82909 Author: Marek Lindner mareklindner@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: 2443ba3 ("batman-adv: roaming handling mechanism redesign")
Reported-by: alfonsname@web.de Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Acked-by: Antonio Quartulli antonio@meshcoding.com
af912d77181f252e6fdd324592d006e30bc82909 translation-table.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/translation-table.c b/translation-table.c index 807a4e6..dfe8896 100644 --- a/translation-table.c +++ b/translation-table.c @@ -1019,6 +1019,7 @@ 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) @@ -1046,7 +1047,15 @@ 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 */