Commit ceffcc5e authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

net_sched: hold netns refcnt for each action 



TC actions have been destroyed asynchronously for a long time,
previously in a RCU callback and now in a workqueue. If we
don't hold a refcnt for its netns, we could use the per netns
data structure, struct tcf_idrinfo, after it has been freed by
netns workqueue.

Hold refcnt to ensure netns destroy happens after all actions
are gone.

Fixes: ddf97ccd ("net_sched: add network namespace support for tc actions")
Reported-by: default avatarLucas Bates <lucasb@mojatatu.com>
Tested-by: default avatarLucas Bates <lucasb@mojatatu.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a159d3c4

include/net/act_api.h

+3 −1
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
struct tcf_idrinfo {

	spinlock_t	lock;

	struct idr	action_idr;

	struct net	*net;

};



struct tc_action_ops;
@@ -104,7 +105,7 @@ struct tc_action_net { 


static inline

int tc_action_net_init(struct tc_action_net *tn,

		       const struct tc_action_ops *ops)

		       const struct tc_action_ops *ops, struct net *net)

{

	int err = 0;
@@ -112,6 +113,7 @@ int tc_action_net_init(struct tc_action_net *tn, 
	if (!tn->idrinfo)

		return -ENOMEM;

	tn->ops = ops;

	tn->idrinfo->net = net;

	spin_lock_init(&tn->idrinfo->lock);

	idr_init(&tn->idrinfo->action_idr);

	return err;

net/sched/act_api.c

+2 −0
Original line number Diff line number Diff line
@@ -78,6 +78,7 @@ static void tcf_idr_remove(struct tcf_idrinfo *idrinfo, struct tc_action *p) 
	spin_lock_bh(&idrinfo->lock);

	idr_remove_ext(&idrinfo->action_idr, p->tcfa_index);

	spin_unlock_bh(&idrinfo->lock);

	put_net(idrinfo->net);

	gen_kill_estimator(&p->tcfa_rate_est);

	free_tcf(p);

}
@@ -336,6 +337,7 @@ err3: 
	p->idrinfo = idrinfo;

	p->ops = ops;

	INIT_LIST_HEAD(&p->list);

	get_net(idrinfo->net);

	*a = p;

	return 0;

}

net/sched/act_bpf.c

+1 −1
Original line number Diff line number Diff line
@@ -398,7 +398,7 @@ static __net_init int bpf_init_net(struct net *net) 
{

	struct tc_action_net *tn = net_generic(net, bpf_net_id);



	return tc_action_net_init(tn, &act_bpf_ops);

	return tc_action_net_init(tn, &act_bpf_ops, net);

}



static void __net_exit bpf_exit_net(struct net *net)

net/sched/act_connmark.c

+1 −1
Original line number Diff line number Diff line
@@ -206,7 +206,7 @@ static __net_init int connmark_init_net(struct net *net) 
{

	struct tc_action_net *tn = net_generic(net, connmark_net_id);



	return tc_action_net_init(tn, &act_connmark_ops);

	return tc_action_net_init(tn, &act_connmark_ops, net);

}



static void __net_exit connmark_exit_net(struct net *net)

net/sched/act_csum.c

+1 −1
Original line number Diff line number Diff line
@@ -626,7 +626,7 @@ static __net_init int csum_init_net(struct net *net) 
{

	struct tc_action_net *tn = net_generic(net, csum_net_id);



	return tc_action_net_init(tn, &act_csum_ops);

	return tc_action_net_init(tn, &act_csum_ops, net);

}



static void __net_exit csum_exit_net(struct net *net)

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