4.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marek Lindner <mareklindner@xxxxxxxxxxxxx>
commit ef72706a0543d0c3a5ab29bd6378fdfb368118d9 upstream.
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@xxxxxx
Signed-off-by: Marek Lindner <mareklindner@xxxxxxxxxxxxx>
Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/batman-adv/translation-table.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1018,6 +1018,7 @@ uint16_t batadv_tt_local_remove(struct b
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)
@@ -1045,7 +1046,15 @@ uint16_t batadv_tt_local_remove(struct b
* 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 */
--
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