macsec: use after free when deleting the underlying device
macsec_notify() loops over the list of macsec devices configured on the
underlying device when this device is being removed. This list is part
of the rx_handler data.
However, macsec_dellink unregisters the rx_handler and frees the
rx_handler data when the last macsec device is removed from the
underlying device.
Add macsec_common_dellink() to delete macsec devices without
unregistering the rx_handler and freeing the associated data.
Fixes: 960d5848dbf1 ("macsec: fix memory leaks around rx_handler (un)registration")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index d13e6e1..dbd590a 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -3047,22 +3047,29 @@
}
}
+static void macsec_common_dellink(struct net_device *dev, struct list_head *head)
+{
+ struct macsec_dev *macsec = macsec_priv(dev);
+
+ unregister_netdevice_queue(dev, head);
+ list_del_rcu(&macsec->secys);
+ macsec_del_dev(macsec);
+
+ macsec_generation++;
+}
+
static void macsec_dellink(struct net_device *dev, struct list_head *head)
{
struct macsec_dev *macsec = macsec_priv(dev);
struct net_device *real_dev = macsec->real_dev;
struct macsec_rxh_data *rxd = macsec_data_rtnl(real_dev);
- macsec_generation++;
+ macsec_common_dellink(dev, head);
- unregister_netdevice_queue(dev, head);
- list_del_rcu(&macsec->secys);
if (list_empty(&rxd->secys)) {
netdev_rx_handler_unregister(real_dev);
kfree(rxd);
}
-
- macsec_del_dev(macsec);
}
static int register_macsec_dev(struct net_device *real_dev,
@@ -3382,8 +3389,12 @@
rxd = macsec_data_rtnl(real_dev);
list_for_each_entry_safe(m, n, &rxd->secys, secys) {
- macsec_dellink(m->secy.netdev, &head);
+ macsec_common_dellink(m->secy.netdev, &head);
}
+
+ netdev_rx_handler_unregister(real_dev);
+ kfree(rxd);
+
unregister_netdevice_many(&head);
break;
}