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| author | Vasily Averin <vvs@virtuozzo.com> | 2021-07-01 07:02:24 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-07-02 02:07:01 +0200 |
| commit | a23f89a9990684a0ca0cac4a2857c15d338ebe2d (patch) | |
| tree | 893c45624613b5c76690ef0c21bde479c29d6cd8 /net | |
| parent | netfilter: nf_tables: Fix dereference of null pointer flow (diff) | |
| download | linux-a23f89a9990684a0ca0cac4a2857c15d338ebe2d.tar.xz linux-a23f89a9990684a0ca0cac4a2857c15d338ebe2d.zip | |
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 <vvs@virtuozzo.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_conntrack_core.c | 1 | ||||
| -rw-r--r-- | net/netfilter/nf_conntrack_proto.c | 7 | ||||
| -rw-r--r-- | net/netfilter/nf_conntrack_proto_gre.c | 13 |
3 files changed, 0 insertions, 21 deletions
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) { |