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Commit 419df12f authored by WANG Cong's avatar WANG Cong Committed by David S. Miller
Browse files

net: move fib_rules_unregister() under rtnl lock 



We have to hold rtnl lock for fib_rules_unregister()
otherwise the following race could happen:

fib_rules_unregister():	fib_nl_delrule():
...				...
...				ops = lookup_rules_ops();
list_del_rcu(&ops->list);
				list_for_each_entry(ops->rules) {
fib_rules_cleanup_ops(ops);	  ...
  list_del_rcu();		  list_del_rcu();
				}

Note, net->rules_mod_lock is actually not needed at all,
either upper layer netns code or rtnl lock guarantees
we are safe.

Cc: Alexander Duyck <alexander.h.duyck@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ed785309

net/core/fib_rules.c

+1 −1
Original line number Diff line number Diff line
@@ -175,9 +175,9 @@ void fib_rules_unregister(struct fib_rules_ops *ops) 


	spin_lock(&net->rules_mod_lock);

	list_del_rcu(&ops->list);

	fib_rules_cleanup_ops(ops);

	spin_unlock(&net->rules_mod_lock);



	fib_rules_cleanup_ops(ops);

	call_rcu(&ops->rcu, fib_rules_put_rcu);

}

EXPORT_SYMBOL_GPL(fib_rules_unregister);

net/decnet/dn_rules.c

+2 −0
Original line number Diff line number Diff line
@@ -248,7 +248,9 @@ void __init dn_fib_rules_init(void) 


void __exit dn_fib_rules_cleanup(void)

{

	rtnl_lock();

	fib_rules_unregister(dn_fib_rules_ops);

	rtnl_unlock();

	rcu_barrier();

}

net/ipv4/fib_frontend.c

+1 −2
Original line number Diff line number Diff line
@@ -1111,11 +1111,10 @@ static void ip_fib_net_exit(struct net *net) 
{

	unsigned int i;



	rtnl_lock();

#ifdef CONFIG_IP_MULTIPLE_TABLES

	fib4_rules_exit(net);

#endif



	rtnl_lock();

	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {

		struct fib_table *tb;

		struct hlist_head *head;

net/ipv4/ipmr.c

+1 −1
Original line number Diff line number Diff line
@@ -283,8 +283,8 @@ static void __net_exit ipmr_rules_exit(struct net *net) 
		list_del(&mrt->list);

		ipmr_free_table(mrt);

	}

	rtnl_unlock();

	fib_rules_unregister(net->ipv4.mr_rules_ops);

	rtnl_unlock();

}

#else

#define ipmr_for_each_table(mrt, net) \

net/ipv6/fib6_rules.c

+2 −0
Original line number Diff line number Diff line
@@ -322,7 +322,9 @@ static int __net_init fib6_rules_net_init(struct net *net) 


static void __net_exit fib6_rules_net_exit(struct net *net)

{

	rtnl_lock();

	fib_rules_unregister(net->ipv6.fib6_rules_ops);

	rtnl_unlock();

}



static struct pernet_operations fib6_rules_net_ops = {