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net: move fib_rules_unregister() under rtnl lock

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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: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
WANG Cong 2015-03-31 11:01:46 -07:00 committed by David S. Miller
parent ed785309c9
commit 419df12fb5
6 changed files with 8 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
net/core/fib_rules.c
View file

@ -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);

2
net/decnet/dn_rules.c
View file

@ -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();
}

3
net/ipv4/fib_frontend.c
View file

@ -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;

2
net/ipv4/ipmr.c
View file

@ -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) \

2
net/ipv6/fib6_rules.c
View file

@ -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 = {

2
net/ipv6/ip6mr.c
View file

@ -267,8 +267,8 @@ static void __net_exit ip6mr_rules_exit(struct net *net)
list_del(&mrt->list);
ip6mr_free_table(mrt);
}
rtnl_unlock();
fib_rules_unregister(net->ipv6.mr6_rules_ops);
rtnl_unlock();
}
#else
#define ip6mr_for_each_table(mrt, net) \