| Message ID | 1427824907-13331-2-git-send-email-xiyou.wangcong@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Cong Wang <xiyou.wangcong@gmail.com> Date: Tue, 31 Mar 2015 11:01:46 -0700 > 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> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 @@ 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); 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 __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(); } 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 @@ 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; 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 @@ 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) \ 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 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 = { 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 @@ 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) \
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> --- net/core/fib_rules.c | 2 +- net/decnet/dn_rules.c | 2 ++ net/ipv4/fib_frontend.c | 3 +-- net/ipv4/ipmr.c | 2 +- net/ipv6/fib6_rules.c | 2 ++ net/ipv6/ip6mr.c | 2 +- 6 files changed, 8 insertions(+), 5 deletions(-)