path: root/drivers/net/macsec.c
diff options
authorTaehee Yoo <ap420073@gmail.com>2019-10-21 18:47:55 +0000
committerDavid S. Miller <davem@davemloft.net>2019-10-24 14:53:48 -0700
commit2bce1ebed17da54c65042ec2b962e3234bad5b47 (patch)
treec72c76fcb1da9f1cc6e9af99599083cee38af725 /drivers/net/macsec.c
parentteam: fix nested locking lockdep warning (diff)
macsec: fix refcnt leak in module exit routine
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> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index e2a3d1d5795f..9e97b66b26d3 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -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;
- 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);