From: David Wilder <dwilder@us.ibm.com>
Date: Mon, 22 Jun 2020 10:10:13 -0700
Subject: netfilter: ip6tables: Split ip6t_unregister_table() into pre_exit and exit helpers.
Patch-mainline: v5.8-rc3
Git-commit: 57ea5f18882a3d7cf6135fa8c949a37c89395837
References: bsc#1171857
The pre_exit will un-register the underlying hook and .exit will do
the table freeing. The netns core does an unconditional synchronize_rcu
after the pre_exit hooks insuring no packets are in flight that have
picked up the pointer before completing the un-register.
Fixes: b9e69e127397 ("netfilter: xtables: don't hook tables by default")
Signed-off-by: David Wilder <dwilder@us.ibm.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
include/linux/netfilter_ipv6/ip6_tables.h | 3 +++
net/ipv6/netfilter/ip6_tables.c | 15 ++++++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)
--- a/include/linux/netfilter_ipv6/ip6_tables.h
+++ b/include/linux/netfilter_ipv6/ip6_tables.h
@@ -31,6 +31,9 @@ int ip6t_register_table(struct net *net, const struct xt_table *table,
const struct nf_hook_ops *ops, struct xt_table **res);
void ip6t_unregister_table(struct net *net, struct xt_table *table,
const struct nf_hook_ops *ops);
+void ip6t_unregister_table_pre_exit(struct net *net, struct xt_table *table,
+ const struct nf_hook_ops *ops);
+void ip6t_unregister_table_exit(struct net *net, struct xt_table *table);
extern unsigned int ip6t_do_table(struct sk_buff *skb,
const struct nf_hook_state *state,
struct xt_table *table);
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1807,11 +1807,22 @@ int ip6t_register_table(struct net *net, const struct xt_table *table,
return ret;
}
+void ip6t_unregister_table_pre_exit(struct net *net, struct xt_table *table,
+ const struct nf_hook_ops *ops)
+{
+ nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
+}
+
+void ip6t_unregister_table_exit(struct net *net, struct xt_table *table)
+{
+ __ip6t_unregister_table(net, table);
+}
+
void ip6t_unregister_table(struct net *net, struct xt_table *table,
const struct nf_hook_ops *ops)
{
if (ops)
- nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks));
+ ip6t_unregister_table_pre_exit(net, table, ops);
__ip6t_unregister_table(net, table);
}
@@ -1969,6 +1980,8 @@ static void __exit ip6_tables_fini(void)
EXPORT_SYMBOL(ip6t_register_table);
EXPORT_SYMBOL(ip6t_unregister_table);
+EXPORT_SYMBOL(ip6t_unregister_table_pre_exit);
+EXPORT_SYMBOL(ip6t_unregister_table_exit);
EXPORT_SYMBOL(ip6t_do_table);
module_init(ip6_tables_init);