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authorMarek Lindner <mareklindner@neomailbox.ch>2015-06-17 14:01:36 +0200
committerAntonio Quartulli <antonio@meshcoding.com>2015-08-05 00:31:47 +0200
commitef72706a0543d0c3a5ab29bd6378fdfb368118d9 (patch)
tree5a485c9fbb22698333415e7804510ff108d21e20 /net
parentbatman-adv: fix kernel crash due to missing NULL checks (diff)
downloadlinux-ef72706a0543d0c3a5ab29bd6378fdfb368118d9.tar.xz
linux-ef72706a0543d0c3a5ab29bd6378fdfb368118d9.zip
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@web.de Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Diffstat (limited to 'net')
-rw-r--r--net/batman-adv/translation-table.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 38b83c50f936..5e953297d3b2 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 */