From 91b6df6611b7edb28676c4f63f90c56c30d3e601 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Thu, 25 Jul 2024 12:28:21 -0700 Subject: [PATCH] netfilter: iptables: Fix potential null-ptr-deref in ip6table_nat_table_init(). [ Upstream commit c22921df777de5606f1047b1345b8d22ef1c0b34 ] ip6table_nat_table_init() accesses net->gen->ptr[ip6table_nat_net_ops.id], but the function is exposed to user space before the entry is allocated via register_pernet_subsys(). Let's call register_pernet_subsys() before xt_register_template(). Fixes: fdacd57c79b7 ("netfilter: x_tables: never register tables by default") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/ipv6/netfilter/ip6table_nat.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/net/ipv6/netfilter/ip6table_nat.c b/net/ipv6/netfilter/ip6table_nat.c index bf3cb3a13600cd..52d597b16b658b 100644 --- a/net/ipv6/netfilter/ip6table_nat.c +++ b/net/ipv6/netfilter/ip6table_nat.c @@ -147,23 +147,27 @@ static struct pernet_operations ip6table_nat_net_ops = { static int __init ip6table_nat_init(void) { - int ret = xt_register_template(&nf_nat_ipv6_table, - ip6table_nat_table_init); + int ret; + /* net->gen->ptr[ip6table_nat_net_id] must be allocated + * before calling ip6t_nat_register_lookups(). + */ + ret = register_pernet_subsys(&ip6table_nat_net_ops); if (ret < 0) return ret; - ret = register_pernet_subsys(&ip6table_nat_net_ops); + ret = xt_register_template(&nf_nat_ipv6_table, + ip6table_nat_table_init); if (ret) - xt_unregister_template(&nf_nat_ipv6_table); + unregister_pernet_subsys(&ip6table_nat_net_ops); return ret; } static void __exit ip6table_nat_exit(void) { - unregister_pernet_subsys(&ip6table_nat_net_ops); xt_unregister_template(&nf_nat_ipv6_table); + unregister_pernet_subsys(&ip6table_nat_net_ops); } module_init(ip6table_nat_init);