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/core/fib_rules.c b/net/core/fib_rules.c
index 44706e8..e4fdc9d 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -175,9 +175,9 @@
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);
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();
}
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 57be71d..23b9b3e 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -1111,11 +1111,10 @@
{
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;
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index bc40115..fe54eba 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -283,8 +283,8 @@
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) \
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 27ca796..70bc6ab 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -322,7 +322,9 @@
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 = {
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 52028f4..2f1fd9f 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -267,8 +267,8 @@
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) \