Patch "netfilter: nf_tables: reject unbound anonymous set before commit phase" has been added to the 6.3-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    netfilter: nf_tables: reject unbound anonymous set before commit phase

to the 6.3-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netfilter-nf_tables-reject-unbound-anonymous-set-bef.patch
and it can be found in the queue-6.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit ebe7866ae2d380bb07b15ec501eb763f6f28664b
Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Date:   Fri Jun 16 15:21:33 2023 +0200

    netfilter: nf_tables: reject unbound anonymous set before commit phase
    
    [ Upstream commit 938154b93be8cd611ddfd7bafc1849f3c4355201 ]
    
    Add a new list to track set transaction and to check for unbound
    anonymous sets before entering the commit phase.
    
    Bail out at the end of the transaction handling if an anonymous set
    remains unbound.
    
    Fixes: 96518518cc41 ("netfilter: add nftables")
    Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index a0f63c7d1d687..730c63ceee567 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -1565,6 +1565,7 @@ static inline void nft_set_elem_clear_busy(struct nft_set_ext *ext)
  *	struct nft_trans - nf_tables object update in transaction
  *
  *	@list: used internally
+ *	@binding_list: list of objects with possible bindings
  *	@msg_type: message type
  *	@put_net: ctx->net needs to be put
  *	@ctx: transaction context
@@ -1572,6 +1573,7 @@ static inline void nft_set_elem_clear_busy(struct nft_set_ext *ext)
  */
 struct nft_trans {
 	struct list_head		list;
+	struct list_head		binding_list;
 	int				msg_type;
 	bool				put_net;
 	struct nft_ctx			ctx;
@@ -1716,6 +1718,7 @@ static inline int nft_request_module(struct net *net, const char *fmt, ...) { re
 struct nftables_pernet {
 	struct list_head	tables;
 	struct list_head	commit_list;
+	struct list_head	binding_list;
 	struct list_head	module_list;
 	struct list_head	notify_list;
 	struct mutex		commit_mutex;
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 4bf532a2a60b9..2e3a374db1b9f 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -153,6 +153,7 @@ static struct nft_trans *nft_trans_alloc_gfp(const struct nft_ctx *ctx,
 		return NULL;
 
 	INIT_LIST_HEAD(&trans->list);
+	INIT_LIST_HEAD(&trans->binding_list);
 	trans->msg_type = msg_type;
 	trans->ctx	= *ctx;
 
@@ -165,9 +166,15 @@ static struct nft_trans *nft_trans_alloc(const struct nft_ctx *ctx,
 	return nft_trans_alloc_gfp(ctx, msg_type, size, GFP_KERNEL);
 }
 
-static void nft_trans_destroy(struct nft_trans *trans)
+static void nft_trans_list_del(struct nft_trans *trans)
 {
 	list_del(&trans->list);
+	list_del(&trans->binding_list);
+}
+
+static void nft_trans_destroy(struct nft_trans *trans)
+{
+	nft_trans_list_del(trans);
 	kfree(trans);
 }
 
@@ -359,6 +366,14 @@ static void nft_trans_commit_list_add_tail(struct net *net, struct nft_trans *tr
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
 
+	switch (trans->msg_type) {
+	case NFT_MSG_NEWSET:
+		if (!nft_trans_set_update(trans) &&
+		    nft_set_is_anonymous(nft_trans_set(trans)))
+			list_add_tail(&trans->binding_list, &nft_net->binding_list);
+		break;
+	}
+
 	list_add_tail(&trans->list, &nft_net->commit_list);
 }
 
@@ -9027,7 +9042,7 @@ static void nf_tables_trans_destroy_work(struct work_struct *w)
 	synchronize_rcu();
 
 	list_for_each_entry_safe(trans, next, &head, list) {
-		list_del(&trans->list);
+		nft_trans_list_del(trans);
 		nft_commit_release(trans);
 	}
 }
@@ -9394,6 +9409,19 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 		return 0;
 	}
 
+	list_for_each_entry(trans, &nft_net->binding_list, binding_list) {
+		switch (trans->msg_type) {
+		case NFT_MSG_NEWSET:
+			if (!nft_trans_set_update(trans) &&
+			    nft_set_is_anonymous(nft_trans_set(trans)) &&
+			    !nft_trans_set_bound(trans)) {
+				pr_warn_once("nftables ruleset with unbound set\n");
+				return -EINVAL;
+			}
+			break;
+		}
+	}
+
 	/* 0. Validate ruleset, otherwise roll back for error reporting. */
 	if (nf_tables_validate(net) < 0)
 		return -EAGAIN;
@@ -9893,7 +9921,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 
 	list_for_each_entry_safe_reverse(trans, next,
 					 &nft_net->commit_list, list) {
-		list_del(&trans->list);
+		nft_trans_list_del(trans);
 		nf_tables_abort_release(trans);
 	}
 
@@ -10669,6 +10697,7 @@ static int __net_init nf_tables_init_net(struct net *net)
 
 	INIT_LIST_HEAD(&nft_net->tables);
 	INIT_LIST_HEAD(&nft_net->commit_list);
+	INIT_LIST_HEAD(&nft_net->binding_list);
 	INIT_LIST_HEAD(&nft_net->module_list);
 	INIT_LIST_HEAD(&nft_net->notify_list);
 	mutex_init(&nft_net->commit_mutex);