From 13210fc63f353fe78584048079343413a3cdf819 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 2 Jan 2025 13:01:13 +0100 Subject: netfilter: nf_tables: imbalance in flowtable binding All these cases cause imbalance between BIND and UNBIND calls: - Delete an interface from a flowtable with multiple interfaces - Add a (device to a) flowtable with --check flag - Delete a netns containing a flowtable - In an interactive nft session, create a table with owner flag and flowtable inside, then quit. Fix it by calling FLOW_BLOCK_UNBIND when unregistering hooks, then remove late FLOW_BLOCK_UNBIND call when destroying flowtable. Fixes: ff4bf2f42a40 ("netfilter: nf_tables: add nft_unregister_flowtable_hook()") Reported-by: Phil Sutter Tested-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 0b9f1e8dfe49..c4af283356e7 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8822,6 +8822,7 @@ static void nft_unregister_flowtable_hook(struct net *net, } static void __nft_unregister_flowtable_net_hooks(struct net *net, + struct nft_flowtable *flowtable, struct list_head *hook_list, bool release_netdev) { @@ -8829,6 +8830,8 @@ static void __nft_unregister_flowtable_net_hooks(struct net *net, list_for_each_entry_safe(hook, next, hook_list, list) { nf_unregister_net_hook(net, &hook->ops); + flowtable->data.type->setup(&flowtable->data, hook->ops.dev, + FLOW_BLOCK_UNBIND); if (release_netdev) { list_del(&hook->list); kfree_rcu(hook, rcu); @@ -8837,9 +8840,10 @@ static void __nft_unregister_flowtable_net_hooks(struct net *net, } static void nft_unregister_flowtable_net_hooks(struct net *net, + struct nft_flowtable *flowtable, struct list_head *hook_list) { - __nft_unregister_flowtable_net_hooks(net, hook_list, false); + __nft_unregister_flowtable_net_hooks(net, flowtable, hook_list, false); } static int nft_register_flowtable_net_hooks(struct net *net, @@ -9481,8 +9485,6 @@ static void nf_tables_flowtable_destroy(struct nft_flowtable *flowtable) flowtable->data.type->free(&flowtable->data); list_for_each_entry_safe(hook, next, &flowtable->hook_list, list) { - flowtable->data.type->setup(&flowtable->data, hook->ops.dev, - FLOW_BLOCK_UNBIND); list_del_rcu(&hook->list); kfree_rcu(hook, rcu); } @@ -10870,6 +10872,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) &nft_trans_flowtable_hooks(trans), trans->msg_type); nft_unregister_flowtable_net_hooks(net, + nft_trans_flowtable(trans), &nft_trans_flowtable_hooks(trans)); } else { list_del_rcu(&nft_trans_flowtable(trans)->list); @@ -10878,6 +10881,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) NULL, trans->msg_type); nft_unregister_flowtable_net_hooks(net, + nft_trans_flowtable(trans), &nft_trans_flowtable(trans)->hook_list); } break; @@ -11140,11 +11144,13 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) case NFT_MSG_NEWFLOWTABLE: if (nft_trans_flowtable_update(trans)) { nft_unregister_flowtable_net_hooks(net, + nft_trans_flowtable(trans), &nft_trans_flowtable_hooks(trans)); } else { nft_use_dec_restore(&table->use); list_del_rcu(&nft_trans_flowtable(trans)->list); nft_unregister_flowtable_net_hooks(net, + nft_trans_flowtable(trans), &nft_trans_flowtable(trans)->hook_list); } break; @@ -11737,7 +11743,8 @@ static void __nft_release_hook(struct net *net, struct nft_table *table) list_for_each_entry(chain, &table->chains, list) __nf_tables_unregister_hook(net, table, chain, true); list_for_each_entry(flowtable, &table->flowtables, list) - __nft_unregister_flowtable_net_hooks(net, &flowtable->hook_list, + __nft_unregister_flowtable_net_hooks(net, flowtable, + &flowtable->hook_list, true); } -- cgit v1.2.3 From b541ba7d1f5a5b7b3e2e22dc9e40e18a7d6dbc13 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 8 Jan 2025 22:56:33 +0100 Subject: netfilter: conntrack: clamp maximum hashtable size to INT_MAX Use INT_MAX as maximum size for the conntrack hashtable. Otherwise, it is possible to hit WARN_ON_ONCE in __kvmalloc_node_noprof() when resizing hashtable because __GFP_NOWARN is unset. See: 0708a0afe291 ("mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls") Note: hashtable resize is only possible from init_netns. Fixes: 9cc1c73ad666 ("netfilter: conntrack: avoid integer overflow when resizing") Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 9db3e2b0b1c3..456446d7af20 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -2517,12 +2517,15 @@ void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls) struct hlist_nulls_head *hash; unsigned int nr_slots, i; - if (*sizep > (UINT_MAX / sizeof(struct hlist_nulls_head))) + if (*sizep > (INT_MAX / sizeof(struct hlist_nulls_head))) return NULL; BUILD_BUG_ON(sizeof(struct hlist_nulls_head) != sizeof(struct hlist_head)); nr_slots = *sizep = roundup(*sizep, PAGE_SIZE / sizeof(struct hlist_nulls_head)); + if (nr_slots > (INT_MAX / sizeof(struct hlist_nulls_head))) + return NULL; + hash = kvcalloc(nr_slots, sizeof(struct hlist_nulls_head), GFP_KERNEL); if (hash && nulls) -- cgit v1.2.3