[PATCH 1/2 v5.10] netfilter: nf_tables: restrict tunnel object to NFPROTO_NETDEV

[PATCH 1/2 v5.10] netfilter: nf_tables: restrict tunnel object to NFPROTO_NETDEV

[Kuntal Nayak]

From: Pablo Neira Ayuso <pablo@netfilter.org>

[ upstream commit 776d451648443f9884be4a1b4e38e8faf1c621f9 ]

Bail out on using the tunnel dst template from other than netdev family.
Add the infrastructure to check for the family in objects.

Fixes: af308b94a2a4 ("netfilter: nf_tables: add tunnel support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[KN: Backport patch according to v5.10.x source]
Signed-off-by: Kuntal Nayak <kuntal.nayak@broadcom.com>
---
 include/net/netfilter/nf_tables.h |  2 ++
 net/netfilter/nf_tables_api.c     | 14 +++++++++-----
 net/netfilter/nft_tunnel.c        |  1 +
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 2da11d8c0..ab8d84775 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -1174,6 +1174,7 @@ void nft_obj_notify(struct net *net, const struct nft_table *table,
  *	@type: stateful object numeric type
  *	@owner: module owner
  *	@maxattr: maximum netlink attribute
+ *	@family: address family for AF-specific object types
  *	@policy: netlink attribute policy
  */
 struct nft_object_type {
@@ -1183,6 +1184,7 @@ struct nft_object_type {
 	struct list_head		list;
 	u32				type;
 	unsigned int                    maxattr;
+	u8				family;
 	struct module			*owner;
 	const struct nla_policy		*policy;
 };
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 858d09b54..de56f25dc 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6234,11 +6234,15 @@ static int nft_object_dump(struct sk_buff *skb, unsigned int attr,
 	return -1;
 }
 
-static const struct nft_object_type *__nft_obj_type_get(u32 objtype)
+static const struct nft_object_type *__nft_obj_type_get(u32 objtype, u8 family)
 {
 	const struct nft_object_type *type;
 
 	list_for_each_entry(type, &nf_tables_objects, list) {
+		if (type->family != NFPROTO_UNSPEC &&
+		    type->family != family)
+			continue;
+
 		if (objtype == type->type)
 			return type;
 	}
@@ -6246,11 +6250,11 @@ static const struct nft_object_type *__nft_obj_type_get(u32 objtype)
 }
 
 static const struct nft_object_type *
-nft_obj_type_get(struct net *net, u32 objtype)
+nft_obj_type_get(struct net *net, u32 objtype, u8 family)
 {
 	const struct nft_object_type *type;
 
-	type = __nft_obj_type_get(objtype);
+	type = __nft_obj_type_get(objtype, family);
 	if (type != NULL && try_module_get(type->owner))
 		return type;
 
@@ -6343,7 +6347,7 @@ static int nf_tables_newobj(struct net *net, struct sock *nlsk,
 		if (nlh->nlmsg_flags & NLM_F_REPLACE)
 			return -EOPNOTSUPP;
 
-		type = __nft_obj_type_get(objtype);
+		type = __nft_obj_type_get(objtype, family);
 		nft_ctx_init(&ctx, net, skb, nlh, family, table, NULL, nla);
 
 		return nf_tables_updobj(&ctx, type, nla[NFTA_OBJ_DATA], obj);
@@ -6354,7 +6358,7 @@ static int nf_tables_newobj(struct net *net, struct sock *nlsk,
 	if (!nft_use_inc(&table->use))
 		return -EMFILE;
 
-	type = nft_obj_type_get(net, objtype);
+	type = nft_obj_type_get(net, objtype, family);
 	if (IS_ERR(type)) {
 		err = PTR_ERR(type);
 		goto err_type;
diff --git a/net/netfilter/nft_tunnel.c b/net/netfilter/nft_tunnel.c
index 2ee50996d..c8822fa81 100644
--- a/net/netfilter/nft_tunnel.c
+++ b/net/netfilter/nft_tunnel.c
@@ -684,6 +684,7 @@ static const struct nft_object_ops nft_tunnel_obj_ops = {
 
 static struct nft_object_type nft_tunnel_obj_type __read_mostly = {
 	.type		= NFT_OBJECT_TUNNEL,
+	.family		= NFPROTO_NETDEV,
 	.ops		= &nft_tunnel_obj_ops,
 	.maxattr	= NFTA_TUNNEL_KEY_MAX,
 	.policy		= nft_tunnel_key_policy,
-- 
2.39.3

[PATCH 2/2 v5.10] netfilter: nf_tables: Fix potential data-race in __nft_obj_type_get()

[Kuntal Nayak]

From: Ziyang Xuan <william.xuanziyang@huawei.com>

[ upstream commit d78d867dcea69c328db30df665be5be7d0148484 ]

nft_unregister_obj() can concurrent with __nft_obj_type_get(),
and there is not any protection when iterate over nf_tables_objects
list in __nft_obj_type_get(). Therefore, there is potential data-race
of nf_tables_objects list entry.

Use list_for_each_entry_rcu() to iterate over nf_tables_objects
list in __nft_obj_type_get(), and use rcu_read_lock() in the caller
nft_obj_type_get() to protect the entire type query process.

Fixes: e50092404c1b ("netfilter: nf_tables: add stateful objects")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Kuntal Nayak <kuntal.nayak@broadcom.com>
---
 net/netfilter/nf_tables_api.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index de56f25dc..f3cb5c920 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -6238,7 +6238,7 @@ static const struct nft_object_type *__nft_obj_type_get(u32 objtype, u8 family)
 {
 	const struct nft_object_type *type;
 
-	list_for_each_entry(type, &nf_tables_objects, list) {
+	list_for_each_entry_rcu(type, &nf_tables_objects, list) {
 		if (type->family != NFPROTO_UNSPEC &&
 		    type->family != family)
 			continue;
@@ -6254,9 +6254,13 @@ nft_obj_type_get(struct net *net, u32 objtype, u8 family)
 {
 	const struct nft_object_type *type;
 
+	rcu_read_lock();
 	type = __nft_obj_type_get(objtype, family);
-	if (type != NULL && try_module_get(type->owner))
+	if (type != NULL && try_module_get(type->owner)) {
+		rcu_read_unlock();
 		return type;
+	}
+	rcu_read_unlock();
 
 	lockdep_nfnl_nft_mutex_not_held();
 #ifdef CONFIG_MODULES
-- 
2.39.3

Re: [PATCH 1/2 v5.10] netfilter: nf_tables: restrict tunnel object to NFPROTO_NETDEV

[Greg KH]

On Fri, Jun 07, 2024 at 02:37:34PM -0700, Kuntal Nayak wrote:
> From: Pablo Neira Ayuso <pablo@netfilter.org>
> 
> [ upstream commit 776d451648443f9884be4a1b4e38e8faf1c621f9 ]
> 
> Bail out on using the tunnel dst template from other than netdev family.
> Add the infrastructure to check for the family in objects.
> 
> Fixes: af308b94a2a4 ("netfilter: nf_tables: add tunnel support")
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> [KN: Backport patch according to v5.10.x source]
> Signed-off-by: Kuntal Nayak <kuntal.nayak@broadcom.com>
> ---
>  include/net/netfilter/nf_tables.h |  2 ++
>  net/netfilter/nf_tables_api.c     | 14 +++++++++-----
>  net/netfilter/nft_tunnel.c        |  1 +
>  3 files changed, 12 insertions(+), 5 deletions(-)

Both now queued up, thanks.

greg k-h