[Patch net] net: move fib_rules_unregister() under rtnl lock
From: Cong Wang <hidden>
Date: 2015-03-31 18:02:53
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
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 <redacted>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Cong Wang <redacted>
---
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(-)
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) \
--
1.8.3.1