From a23f89a9990684a0ca0cac4a2857c15d338ebe2d Mon Sep 17 00:00:00 2001 From: Vasily Averin Date: Thu, 1 Jul 2021 08:02:24 +0300 Subject: [PATCH] netfilter: conntrack: nf_ct_gre_keymap_flush() removal nf_ct_gre_keymap_flush() is useless. It is called from nf_conntrack_cleanup_net_list() only and tries to remove nf_ct_gre_keymap entries from pernet gre keymap list. Though: a) at this point the list should already be empty, all its entries were deleted during the conntracks cleanup, because nf_conntrack_cleanup_net_list() executes nf_ct_iterate_cleanup(kill_all) before nf_conntrack_proto_pernet_fini(): nf_conntrack_cleanup_net_list +- nf_ct_iterate_cleanup | nf_ct_put | nf_conntrack_put | nf_conntrack_destroy | destroy_conntrack | destroy_gre_conntrack | nf_ct_gre_keymap_destroy `- nf_conntrack_proto_pernet_fini nf_ct_gre_keymap_flush b) Let's say we find that the keymap list is not empty. This means netns still has a conntrack associated with gre, in which case we should not free its memory, because this will lead to a double free and related crashes. However I doubt it could have gone unnoticed for years, obviously this does not happen in real life. So I think we can remove both nf_ct_gre_keymap_flush() and nf_conntrack_proto_pernet_fini(). Signed-off-by: Vasily Averin Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_conntrack_core.h | 1 - net/netfilter/nf_conntrack_core.c | 1 - net/netfilter/nf_conntrack_proto.c | 7 ------- net/netfilter/nf_conntrack_proto_gre.c | 13 ------------- 4 files changed, 22 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h index 09f2efea0b97..13807ea94cd2 100644 --- a/include/net/netfilter/nf_conntrack_core.h +++ b/include/net/netfilter/nf_conntrack_core.h @@ -30,7 +30,6 @@ void nf_conntrack_cleanup_net(struct net *net); void nf_conntrack_cleanup_net_list(struct list_head *net_exit_list); void nf_conntrack_proto_pernet_init(struct net *net); -void nf_conntrack_proto_pernet_fini(struct net *net); int nf_conntrack_proto_init(void); void nf_conntrack_proto_fini(void); diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 96ba19fc8155..085a11f1eb43 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -2457,7 +2457,6 @@ i_see_dead_people: } list_for_each_entry(net, net_exit_list, exit_list) { - nf_conntrack_proto_pernet_fini(net); nf_conntrack_ecache_pernet_fini(net); nf_conntrack_expect_pernet_fini(net); free_percpu(net->ct.stat); diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c index 55647409a9be..8f7a9837349c 100644 --- a/net/netfilter/nf_conntrack_proto.c +++ b/net/netfilter/nf_conntrack_proto.c @@ -697,13 +697,6 @@ void nf_conntrack_proto_pernet_init(struct net *net) #endif } -void nf_conntrack_proto_pernet_fini(struct net *net) -{ -#ifdef CONFIG_NF_CT_PROTO_GRE - nf_ct_gre_keymap_flush(net); -#endif -} - module_param_call(hashsize, nf_conntrack_set_hashsize, param_get_uint, &nf_conntrack_htable_size, 0600); diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c index db11e403d818..728eeb0aea87 100644 --- a/net/netfilter/nf_conntrack_proto_gre.c +++ b/net/netfilter/nf_conntrack_proto_gre.c @@ -55,19 +55,6 @@ static inline struct nf_gre_net *gre_pernet(struct net *net) return &net->ct.nf_ct_proto.gre; } -void nf_ct_gre_keymap_flush(struct net *net) -{ - struct nf_gre_net *net_gre = gre_pernet(net); - struct nf_ct_gre_keymap *km, *tmp; - - spin_lock_bh(&keymap_lock); - list_for_each_entry_safe(km, tmp, &net_gre->keymap_list, list) { - list_del_rcu(&km->list); - kfree_rcu(km, rcu); - } - spin_unlock_bh(&keymap_lock); -} - static inline int gre_key_cmpfn(const struct nf_ct_gre_keymap *km, const struct nf_conntrack_tuple *t) { -- 2.11.0