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: 35df3b298f ("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>
This commit is contained in:
Marek Lindner 2015-06-09 21:24:36 +08:00 committed by Antonio Quartulli
parent f202a666e9
commit 354136bcc3
2 changed files with 17 additions and 4 deletions

View File

@ -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);

View File

@ -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);
}