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: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/decnet/dn_rules.c b/net/decnet/dn_rules.c
index faf7cc3..9d66a0f 100644
--- a/net/decnet/dn_rules.c
+++ b/net/decnet/dn_rules.c
@@ -248,7 +248,9 @@
void __exit dn_fib_rules_cleanup(void)
{
+ rtnl_lock();
fib_rules_unregister(dn_fib_rules_ops);
+ rtnl_unlock();
rcu_barrier();
}