@@ -3000,12 +3000,10 @@ static const struct nla_policy macsec_rtnl_policy[IFLA_MACSEC_MAX + 1] = {
static void macsec_free_netdev(struct net_device *dev)
{
struct macsec_dev *macsec = macsec_priv(dev);
- struct net_device *real_dev = macsec->real_dev;
free_percpu(macsec->stats);
free_percpu(macsec->secy.tx_sc.stats);
- dev_put(real_dev);
}
static void macsec_setup(struct net_device *dev)
@@ -3260,8 +3258,6 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
if (err < 0)
return err;
- dev_hold(real_dev);
-
macsec->nest_level = dev_get_nest_level(real_dev) + 1;
err = netdev_upper_dev_link(real_dev, dev, extack);
When a macsec interface is created, it increases a refcnt to a lower device(real device). when macsec interface is deleted, the refcnt is decreased in macsec_free_netdev(), which is ->priv_destructor() of macsec interface. The problem scenario is this. When nested macsec interfaces are exiting, the exit routine of the macsec module makes refcnt leaks. Test commands: ip link add dummy0 type dummy ip link add macsec0 link dummy0 type macsec ip link add macsec1 link macsec0 type macsec modprobe -rv macsec [ 208.629433] unregister_netdevice: waiting for macsec0 to become free. Usage count = 1 Steps of exit routine of macsec module are below. 1. Calls ->dellink() in __rtnl_link_unregister(). 2. Checks refcnt and wait refcnt to be 0 if refcnt is not 0 in netdev_run_todo(). 3. Calls ->priv_destruvtor() in netdev_run_todo(). Step2 checks refcnt, but step3 decreases refcnt. So, step2 waits forever. This patch makes the macsec module do not hold a refcnt of the lower device because it already holds a refcnt of the lower device with netdev_upper_dev_link(). Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver") Signed-off-by: Taehee Yoo <ap420073@gmail.com> --- v1 -> v5 : - This patch is not changed drivers/net/macsec.c | 4 ---- 1 file changed, 4 deletions(-)