From 57ea5f18882a3d7cf6135fa8c949a37c89395837 Mon Sep 17 00:00:00 2001 From: David Wilder Date: Mon, 22 Jun 2020 10:10:13 -0700 Subject: [PATCH] netfilter: ip6tables: Split ip6t_unregister_table() into pre_exit and exit helpers. 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 Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter_ipv6/ip6_tables.h | 3 +++ net/ipv6/netfilter/ip6_tables.c | 15 ++++++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/include/linux/netfilter_ipv6/ip6_tables.h b/include/linux/netfilter_ipv6/ip6_tables.h index 8225f7821a29..1547d5f9ae06 100644 --- a/include/linux/netfilter_ipv6/ip6_tables.h +++ b/include/linux/netfilter_ipv6/ip6_tables.h @@ -29,6 +29,9 @@ 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); diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index e27393498ecb..e96a431549bc 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -1807,11 +1807,22 @@ out_free: 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);