From bbe11fab0b6c1d113776b2898e085bf4d1fdc607 Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Thu, 11 Aug 2016 15:24:27 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/macsec.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) 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_del_dev(struct macsec_dev *macsec) } } +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 @@ static int macsec_notify(struct notifier_block *this, unsigned long event, 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; } -- 2.7.4