Commit 224e923c authored Jul 16, 2014 by Cong Wang Committed by David S. Miller Jul 20, 2014

net_sched: hold tcf_lock in netdevice notifier

We modify mirred action (m->tcfm_dev) in netdev event, we need to
prevent on-going mirred actions from reading freed m->tcfm_dev.
So we need to acquire this spin lock.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent e81fbf6c

net/sched/act_mirred.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -218,10 +218,12 @@ static int mirred_device_event(struct notifier_block *unused,

		if (event == NETDEV_UNREGISTER)
		list_for_each_entry(m, &mirred_list, tcfm_list) {
		spin_lock_bh(&m->tcf_lock);
		if (m->tcfm_dev == dev) {
		dev_put(dev);
		m->tcfm_dev = NULL;
		}
		spin_unlock_bh(&m->tcf_lock);
		}

		return NOTIFY_DONE;