Commit f446f48c authored by Marek Lindner's avatar Marek Lindner Committed by Luis Henriques

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

commit 354136bc upstream.

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

Fixes: 35df3b29 ("batman-adv: fix TT VLAN inconsistency on VLAN re-add")
Reported-by: default avatarRyan Thompson <ryan@eero.com>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: default avatarAntonio Quartulli <antonio@meshcoding.com>
Signed-off-by: default avatarLuis Henriques <luis.henriques@canonical.com>
parent 05b474bd
......@@ -450,6 +450,9 @@ void batadv_interface_rx(struct net_device *soft_iface,
*/
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);
......
......@@ -575,6 +575,9 @@ 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",
......@@ -1047,6 +1050,9 @@ 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);
......@@ -1147,8 +1153,10 @@ 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);
}
......@@ -3190,8 +3198,10 @@ 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);
}
......
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