The following commit has been merged in the master branch: commit 354136bcc3c4f40a2813bba8f57ca5267d812d15 Author: Marek Lindner mareklindner@neomailbox.ch Date: Tue Jun 9 21:24:36 2015 +0800

batman-adv: fix kernel crash due to missing NULL checks

batadv_softif_vlan_get() may return NULL which has to be verified by the caller.

Fixes: 35df3b298fc8 ("batman-adv: fix TT VLAN inconsistency on VLAN re-add") Reported-by: Ryan Thompson ryan@eero.com Signed-off-by: Marek Lindner mareklindner@neomailbox.ch Signed-off-by: Antonio Quartulli antonio@meshcoding.com

diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index c002961..a2fc843 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -479,6 +479,9 @@ out: */ void batadv_softif_vlan_free_ref(struct batadv_softif_vlan *vlan) { + if (!vlan) + return; + if (atomic_dec_and_test(&vlan->refcount)) { spin_lock_bh(&vlan->bat_priv->softif_vlan_list_lock); hlist_del_rcu(&vlan->list); diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index b482495..38b83c5 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -594,6 +594,9 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const uint8_t *addr,

/* increase the refcounter of the related vlan */ vlan = batadv_softif_vlan_get(bat_priv, vid); + if (WARN(!vlan, "adding TT local entry %pM to non-existent VLAN %d", + addr, BATADV_PRINT_VID(vid))) + goto out;

batadv_dbg(BATADV_DBG_TT, bat_priv, "Creating new local tt entry: %pM (vid: %d, ttvn: %d)\n", @@ -1066,6 +1069,9 @@ uint16_t batadv_tt_local_remove(struct batadv_priv *bat_priv,

/* decrease the reference held for this vlan */ vlan = batadv_softif_vlan_get(bat_priv, vid); + if (!vlan) + goto out; + batadv_softif_vlan_free_ref(vlan); batadv_softif_vlan_free_ref(vlan);

@@ -1166,8 +1172,10 @@ static void batadv_tt_local_table_free(struct batadv_priv *bat_priv) /* decrease the reference held for this vlan */ vlan = batadv_softif_vlan_get(bat_priv, tt_common_entry->vid); - batadv_softif_vlan_free_ref(vlan); - batadv_softif_vlan_free_ref(vlan); + if (vlan) { + batadv_softif_vlan_free_ref(vlan); + batadv_softif_vlan_free_ref(vlan); + }

batadv_tt_local_entry_free_ref(tt_local); } @@ -3207,8 +3215,10 @@ static void batadv_tt_local_purge_pending_clients(struct batadv_priv *bat_priv)

/* decrease the reference held for this vlan */ vlan = batadv_softif_vlan_get(bat_priv, tt_common->vid); - batadv_softif_vlan_free_ref(vlan); - batadv_softif_vlan_free_ref(vlan); + if (vlan) { + batadv_softif_vlan_free_ref(vlan); + batadv_softif_vlan_free_ref(vlan); + }

batadv_tt_local_entry_free_ref(tt_local); }