netfilter: nftables: update table flags from the commit phase

Do not update table flags from the preparation phase. Store the flags
update into the transaction, then update the flags from the commit
phase.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Author: ummakynes

include/net/netfilter/nf_tables.h

@@ -1498,13 +1498,16 @@ struct nft_trans_chain {
 
 struct nft_trans_table {
 	bool				update;
-	bool				enable;
+	u8				state;
+	u32				flags;
 };
 
 #define nft_trans_table_update(trans)	\
 	(((struct nft_trans_table *)trans->data)->update)
-#define nft_trans_table_enable(trans)	\
-	(((struct nft_trans_table *)trans->data)->enable)
+#define nft_trans_table_state(trans)	\
+	(((struct nft_trans_table *)trans->data)->state)
+#define nft_trans_table_flags(trans)	\
+	(((struct nft_trans_table *)trans->data)->flags)
 
 struct nft_trans_elem {
 	struct nft_set			*set;

net/netfilter/nf_tables_api.c

@@ -900,6 +900,12 @@ static void nf_tables_table_disable(struct net *net, struct nft_table *table)
 	nft_table_disable(net, table, 0);
 }
 
+enum {
+	NFT_TABLE_STATE_UNCHANGED	= 0,
+	NFT_TABLE_STATE_DORMANT,
+	NFT_TABLE_STATE_WAKEUP
+};
+
 static int nf_tables_updtable(struct nft_ctx *ctx)
 {
 	struct nft_trans *trans;
@@ -929,19 +935,17 @@ static int nf_tables_updtable(struct nft_ctx *ctx)
 
 	if ((flags & NFT_TABLE_F_DORMANT) &&
 	    !(ctx->table->flags & NFT_TABLE_F_DORMANT)) {
-		nft_trans_table_enable(trans) = false;
+		nft_trans_table_state(trans) = NFT_TABLE_STATE_DORMANT;
 	} else if (!(flags & NFT_TABLE_F_DORMANT) &&
 		   ctx->table->flags & NFT_TABLE_F_DORMANT) {
-		ctx->table->flags &= ~NFT_TABLE_F_DORMANT;
 		ret = nf_tables_table_enable(ctx->net, ctx->table);
 		if (ret >= 0)
-			nft_trans_table_enable(trans) = true;
-		else
-			ctx->table->flags |= NFT_TABLE_F_DORMANT;
+			nft_trans_table_state(trans) = NFT_TABLE_STATE_WAKEUP;
 	}
 	if (ret < 0)
 		goto err;
 
+	nft_trans_table_flags(trans) = flags;
 	nft_trans_table_update(trans) = true;
 	list_add_tail(&trans->list, &ctx->net->nft.commit_list);
 	return 0;
@@ -8068,11 +8072,10 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 		switch (trans->msg_type) {
 		case NFT_MSG_NEWTABLE:
 			if (nft_trans_table_update(trans)) {
-				if (!nft_trans_table_enable(trans)) {
-					nf_tables_table_disable(net,
-								trans->ctx.table);
-					trans->ctx.table->flags |= NFT_TABLE_F_DORMANT;
-				}
+				if (nft_trans_table_state(trans) == NFT_TABLE_STATE_DORMANT)
+					nf_tables_table_disable(net, trans->ctx.table);
+
+				trans->ctx.table->flags = nft_trans_table_flags(trans);
 			} else {
 				nft_clear(net, trans->ctx.table);
 			}
@@ -8283,11 +8286,9 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action)
 		switch (trans->msg_type) {
 		case NFT_MSG_NEWTABLE:
 			if (nft_trans_table_update(trans)) {
-				if (nft_trans_table_enable(trans)) {
-					nf_tables_table_disable(net,
-								trans->ctx.table);
-					trans->ctx.table->flags |= NFT_TABLE_F_DORMANT;
-				}
+				if (nft_trans_table_state(trans) == NFT_TABLE_STATE_WAKEUP)
+					nf_tables_table_disable(net, trans->ctx.table);
+
 				nft_trans_destroy(trans);
 			} else {
 				list_del_rcu(&trans->ctx.table->list);