merge-f5fc1643a841 from branch/tag: cve/CVE-2023-4244-R105 into branch: release-R105-cos-5.15

Changelog:
-------------------------------------------------------------

Florian Westphal (4):
      netfilter: nf_tables: don't skip expired elements during walk
      netfilter: nf_tables: don't fail inserts if duplicate has expired
      netfilter: nf_tables: defer gc run if previous batch is still pending
      netfilter: nf_tables: fix memleak when more than 255 elements expired

Pablo Neira Ayuso (13):
      netfilter: nf_tables: GC transaction API to avoid race with control plane
      netfilter: nf_tables: adapt set backend to use GC transaction API
      netfilter: nft_set_hash: mark set element as dead when deleting from packet path
      netfilter: nf_tables: remove busy mark and gc batch API
      netfilter: nf_tables: fix GC transaction races with netns and netlink event exit path
      netfilter: nf_tables: GC transaction race with netns dismantle
      netfilter: nf_tables: GC transaction race with abort path
      netfilter: nf_tables: use correct lock to protect gc_list
      netfilter: nft_set_rbtree: skip sync GC for new elements in this transaction
      netfilter: nft_set_rbtree: use read spinlock to avoid datapath contention
      netfilter: nft_set_pipapo: call nft_trans_gc_queue_sync() in catchall GC
      netfilter: nft_set_pipapo: stop GC iteration if GC transaction allocation fails
      netfilter: nft_set_hash: try later when GC hits EAGAIN on iteration

BUG=b/300063331
TEST=tryjob, validation and K8s e2e
RELEASE_NOTE=Fixed CVE-2023-4244 in the Linux kernel.

Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Change-Id: I98019b51976d9bd4b5af79c5b1c8a56381181193
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 1458b3e..098e829fd 100644
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -477,6 +477,7 @@
  *
  *	@list: table set list node
  *	@bindings: list of set bindings
+ *	@refs: internal refcounting for async set destruction
  *	@table: table this set belongs to
  *	@net: netnamespace this set belongs to
  * 	@name: name of the set
@@ -506,6 +507,7 @@
 struct nft_set {
 	struct list_head		list;
 	struct list_head		bindings;
+	refcount_t			refs;
 	struct nft_table		*table;
 	possible_net_t			net;
 	char				*name;
@@ -527,7 +529,8 @@
 	struct list_head		pending_update;
 	/* runtime data below here */
 	const struct nft_set_ops	*ops ____cacheline_aligned;
-	u16				flags:14,
+	u16				flags:13,
+					dead:1,
 					genmask:2;
 	u8				klen;
 	u8				dlen;
@@ -548,6 +551,11 @@
 	return (void *)set->data;
 }
 
+static inline bool nft_set_gc_is_pending(const struct nft_set *s)
+{
+	return refcount_read(&s->refs) != 1;
+}
+
 static inline struct nft_set *nft_set_container_of(const void *priv)
 {
 	return (void *)priv - offsetof(struct nft_set, data);
@@ -561,7 +569,6 @@
 
 struct nft_set_ext *nft_set_catchall_lookup(const struct net *net,
 					    const struct nft_set *set);
-void *nft_set_catchall_gc(const struct nft_set *set);
 
 static inline unsigned long nft_set_gc_interval(const struct nft_set *set)
 {
@@ -776,62 +783,6 @@
 void nf_tables_set_elem_destroy(const struct nft_ctx *ctx,
 				const struct nft_set *set, void *elem);
 
-/**
- *	struct nft_set_gc_batch_head - nf_tables set garbage collection batch
- *
- *	@rcu: rcu head
- *	@set: set the elements belong to
- *	@cnt: count of elements
- */
-struct nft_set_gc_batch_head {
-	struct rcu_head			rcu;
-	const struct nft_set		*set;
-	unsigned int			cnt;
-};
-
-#define NFT_SET_GC_BATCH_SIZE	((PAGE_SIZE -				  \
-				  sizeof(struct nft_set_gc_batch_head)) / \
-				 sizeof(void *))
-
-/**
- *	struct nft_set_gc_batch - nf_tables set garbage collection batch
- *
- * 	@head: GC batch head
- * 	@elems: garbage collection elements
- */
-struct nft_set_gc_batch {
-	struct nft_set_gc_batch_head	head;
-	void				*elems[NFT_SET_GC_BATCH_SIZE];
-};
-
-struct nft_set_gc_batch *nft_set_gc_batch_alloc(const struct nft_set *set,
-						gfp_t gfp);
-void nft_set_gc_batch_release(struct rcu_head *rcu);
-
-static inline void nft_set_gc_batch_complete(struct nft_set_gc_batch *gcb)
-{
-	if (gcb != NULL)
-		call_rcu(&gcb->head.rcu, nft_set_gc_batch_release);
-}
-
-static inline struct nft_set_gc_batch *
-nft_set_gc_batch_check(const struct nft_set *set, struct nft_set_gc_batch *gcb,
-		       gfp_t gfp)
-{
-	if (gcb != NULL) {
-		if (gcb->head.cnt + 1 < ARRAY_SIZE(gcb->elems))
-			return gcb;
-		nft_set_gc_batch_complete(gcb);
-	}
-	return nft_set_gc_batch_alloc(set, gfp);
-}
-
-static inline void nft_set_gc_batch_add(struct nft_set_gc_batch *gcb,
-					void *elem)
-{
-	gcb->elems[gcb->head.cnt++] = elem;
-}
-
 struct nft_expr_ops;
 /**
  *	struct nft_expr_type - nf_tables expression type
@@ -1490,39 +1441,30 @@
 
 #endif /* IS_ENABLED(CONFIG_NF_TABLES) */
 
-/*
- * We use a free bit in the genmask field to indicate the element
- * is busy, meaning it is currently being processed either by
- * the netlink API or GC.
- *
- * Even though the genmask is only a single byte wide, this works
- * because the extension structure if fully constant once initialized,
- * so there are no non-atomic write accesses unless it is already
- * marked busy.
- */
-#define NFT_SET_ELEM_BUSY_MASK	(1 << 2)
+#define NFT_SET_ELEM_DEAD_MASK	(1 << 2)
 
 #if defined(__LITTLE_ENDIAN_BITFIELD)
-#define NFT_SET_ELEM_BUSY_BIT	2
+#define NFT_SET_ELEM_DEAD_BIT	2
 #elif defined(__BIG_ENDIAN_BITFIELD)
-#define NFT_SET_ELEM_BUSY_BIT	(BITS_PER_LONG - BITS_PER_BYTE + 2)
+#define NFT_SET_ELEM_DEAD_BIT	(BITS_PER_LONG - BITS_PER_BYTE + 2)
 #else
 #error
 #endif
 
-static inline int nft_set_elem_mark_busy(struct nft_set_ext *ext)
+static inline void nft_set_elem_dead(struct nft_set_ext *ext)
 {
 	unsigned long *word = (unsigned long *)ext;
 
 	BUILD_BUG_ON(offsetof(struct nft_set_ext, genmask) != 0);
-	return test_and_set_bit(NFT_SET_ELEM_BUSY_BIT, word);
+	set_bit(NFT_SET_ELEM_DEAD_BIT, word);
 }
 
-static inline void nft_set_elem_clear_busy(struct nft_set_ext *ext)
+static inline int nft_set_elem_is_dead(const struct nft_set_ext *ext)
 {
 	unsigned long *word = (unsigned long *)ext;
 
-	clear_bit(NFT_SET_ELEM_BUSY_BIT, word);
+	BUILD_BUG_ON(offsetof(struct nft_set_ext, genmask) != 0);
+	return test_bit(NFT_SET_ELEM_DEAD_BIT, word);
 }
 
 /**
@@ -1656,6 +1598,39 @@
 #define nft_trans_flowtable_flags(trans)	\
 	(((struct nft_trans_flowtable *)trans->data)->flags)
 
+#define NFT_TRANS_GC_BATCHCOUNT	256
+
+struct nft_trans_gc {
+	struct list_head	list;
+	struct net		*net;
+	struct nft_set		*set;
+	u32			seq;
+	u16			count;
+	void			*priv[NFT_TRANS_GC_BATCHCOUNT];
+	struct rcu_head		rcu;
+};
+
+struct nft_trans_gc *nft_trans_gc_alloc(struct nft_set *set,
+					unsigned int gc_seq, gfp_t gfp);
+void nft_trans_gc_destroy(struct nft_trans_gc *trans);
+
+struct nft_trans_gc *nft_trans_gc_queue_async(struct nft_trans_gc *gc,
+					      unsigned int gc_seq, gfp_t gfp);
+void nft_trans_gc_queue_async_done(struct nft_trans_gc *gc);
+
+struct nft_trans_gc *nft_trans_gc_queue_sync(struct nft_trans_gc *gc, gfp_t gfp);
+void nft_trans_gc_queue_sync_done(struct nft_trans_gc *trans);
+
+void nft_trans_gc_elem_add(struct nft_trans_gc *gc, void *priv);
+
+struct nft_trans_gc *nft_trans_gc_catchall_async(struct nft_trans_gc *gc,
+						 unsigned int gc_seq);
+struct nft_trans_gc *nft_trans_gc_catchall_sync(struct nft_trans_gc *gc);
+
+void nft_setelem_data_deactivate(const struct net *net,
+				 const struct nft_set *set,
+				 struct nft_set_elem *elem);
+
 int __init nft_chain_filter_init(void);
 void nft_chain_filter_fini(void);
 
@@ -1683,6 +1658,7 @@
 	u64			table_handle;
 	unsigned int		base_seq;
 	u8			validate_state;
+	unsigned int		gc_seq;
 };
 
 extern unsigned int nf_tables_net_id;
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index a19a911..ba478d2 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -31,7 +31,9 @@
 static LIST_HEAD(nf_tables_objects);
 static LIST_HEAD(nf_tables_flowtables);
 static LIST_HEAD(nf_tables_destroy_list);
+static LIST_HEAD(nf_tables_gc_list);
 static DEFINE_SPINLOCK(nf_tables_destroy_list_lock);
+static DEFINE_SPINLOCK(nf_tables_gc_list_lock);
 
 enum {
 	NFT_VALIDATE_SKIP	= 0,
@@ -122,6 +124,9 @@
 static void nf_tables_trans_destroy_work(struct work_struct *w);
 static DECLARE_WORK(trans_destroy_work, nf_tables_trans_destroy_work);
 
+static void nft_trans_gc_work(struct work_struct *work);
+static DECLARE_WORK(trans_gc_work, nft_trans_gc_work);
+
 static void nft_ctx_init(struct nft_ctx *ctx,
 			 struct net *net,
 			 const struct sk_buff *skb,
@@ -583,10 +588,6 @@
 	return __nft_trans_set_add(ctx, msg_type, set, NULL);
 }
 
-static void nft_setelem_data_deactivate(const struct net *net,
-					const struct nft_set *set,
-					struct nft_set_elem *elem);
-
 static int nft_mapelem_deactivate(const struct nft_ctx *ctx,
 				  struct nft_set *set,
 				  const struct nft_set_iter *iter,
@@ -4765,6 +4766,7 @@
 
 	INIT_LIST_HEAD(&set->bindings);
 	INIT_LIST_HEAD(&set->catchall_list);
+	refcount_set(&set->refs, 1);
 	set->table = table;
 	write_pnet(&set->net, net);
 	set->ops = ops;
@@ -4832,6 +4834,14 @@
 	}
 }
 
+static void nft_set_put(struct nft_set *set)
+{
+	if (refcount_dec_and_test(&set->refs)) {
+		kfree(set->name);
+		kvfree(set);
+	}
+}
+
 static void nft_set_destroy(const struct nft_ctx *ctx, struct nft_set *set)
 {
 	int i;
@@ -4844,8 +4854,7 @@
 
 	set->ops->destroy(ctx, set);
 	nft_set_catchall_destroy(ctx, set);
-	kfree(set->name);
-	kvfree(set);
+	nft_set_put(set);
 }
 
 static int nf_tables_delset(struct sk_buff *skb, const struct nfnl_info *info,
@@ -5297,8 +5306,12 @@
 				  const struct nft_set_iter *iter,
 				  struct nft_set_elem *elem)
 {
+	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
 	struct nft_set_dump_args *args;
 
+	if (nft_set_elem_expired(ext))
+		return 0;
+
 	args = container_of(iter, struct nft_set_dump_args, iter);
 	return nf_tables_fill_setelem(args->skb, set, elem);
 }
@@ -5910,7 +5923,8 @@
 	list_for_each_entry_rcu(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
 		if (nft_set_elem_active(ext, genmask) &&
-		    !nft_set_elem_expired(ext))
+		    !nft_set_elem_expired(ext) &&
+		    !nft_set_elem_is_dead(ext))
 			return ext;
 	}
 
@@ -5918,29 +5932,6 @@
 }
 EXPORT_SYMBOL_GPL(nft_set_catchall_lookup);
 
-void *nft_set_catchall_gc(const struct nft_set *set)
-{
-	struct nft_set_elem_catchall *catchall, *next;
-	struct nft_set_ext *ext;
-	void *elem = NULL;
-
-	list_for_each_entry_safe(catchall, next, &set->catchall_list, list) {
-		ext = nft_set_elem_ext(set, catchall->elem);
-
-		if (!nft_set_elem_expired(ext) ||
-		    nft_set_elem_mark_busy(ext))
-			continue;
-
-		elem = catchall->elem;
-		list_del_rcu(&catchall->list);
-		kfree_rcu(catchall, rcu);
-		break;
-	}
-
-	return elem;
-}
-EXPORT_SYMBOL_GPL(nft_set_catchall_gc);
-
 static int nft_setelem_catchall_insert(const struct net *net,
 				       struct nft_set *set,
 				       const struct nft_set_elem *elem,
@@ -6002,7 +5993,6 @@
 
 	if (nft_setelem_is_catchall(set, elem)) {
 		nft_set_elem_change_active(net, set, ext);
-		nft_set_elem_clear_busy(ext);
 	} else {
 		set->ops->activate(net, set, elem);
 	}
@@ -6017,8 +6007,7 @@
 
 	list_for_each_entry(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
-		if (!nft_is_active(net, ext) ||
-		    nft_set_elem_mark_busy(ext))
+		if (!nft_is_active(net, ext))
 			continue;
 
 		kfree(elem->priv);
@@ -6407,7 +6396,7 @@
 		goto err_elem_expr;
 	}
 
-	ext->genmask = nft_genmask_cur(ctx->net) | NFT_SET_ELEM_BUSY_MASK;
+	ext->genmask = nft_genmask_cur(ctx->net);
 
 	err = nft_setelem_insert(ctx->net, set, &elem, &ext2, flags);
 	if (err) {
@@ -6555,9 +6544,9 @@
 		nft_use_inc_restore(&(*nft_set_ext_obj(ext))->use);
 }
 
-static void nft_setelem_data_deactivate(const struct net *net,
-					const struct nft_set *set,
-					struct nft_set_elem *elem)
+void nft_setelem_data_deactivate(const struct net *net,
+				 const struct nft_set *set,
+				 struct nft_set_elem *elem)
 {
 	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
 
@@ -6719,8 +6708,7 @@
 
 	list_for_each_entry_rcu(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
-		if (!nft_set_elem_active(ext, genmask) ||
-		    nft_set_elem_mark_busy(ext))
+		if (!nft_set_elem_active(ext, genmask))
 			continue;
 
 		elem.priv = catchall->elem;
@@ -6789,29 +6777,6 @@
 	return err;
 }
 
-void nft_set_gc_batch_release(struct rcu_head *rcu)
-{
-	struct nft_set_gc_batch *gcb;
-	unsigned int i;
-
-	gcb = container_of(rcu, struct nft_set_gc_batch, head.rcu);
-	for (i = 0; i < gcb->head.cnt; i++)
-		nft_set_elem_destroy(gcb->head.set, gcb->elems[i], true);
-	kfree(gcb);
-}
-
-struct nft_set_gc_batch *nft_set_gc_batch_alloc(const struct nft_set *set,
-						gfp_t gfp)
-{
-	struct nft_set_gc_batch *gcb;
-
-	gcb = kzalloc(sizeof(*gcb), gfp);
-	if (gcb == NULL)
-		return gcb;
-	gcb->head.set = set;
-	return gcb;
-}
-
 /*
  * Stateful objects
  */
@@ -8891,6 +8856,234 @@
 	list_del_rcu(&chain->list);
 }
 
+static void nft_trans_gc_setelem_remove(struct nft_ctx *ctx,
+					struct nft_trans_gc *trans)
+{
+	void **priv = trans->priv;
+	unsigned int i;
+
+	for (i = 0; i < trans->count; i++) {
+		struct nft_set_elem elem = {
+			.priv = priv[i],
+		};
+
+		nft_setelem_data_deactivate(ctx->net, trans->set, &elem);
+		nft_setelem_remove(ctx->net, trans->set, &elem);
+	}
+}
+
+void nft_trans_gc_destroy(struct nft_trans_gc *trans)
+{
+	nft_set_put(trans->set);
+	put_net(trans->net);
+	kfree(trans);
+}
+
+static void nft_trans_gc_trans_free(struct rcu_head *rcu)
+{
+	struct nft_set_elem elem = {};
+	struct nft_trans_gc *trans;
+	struct nft_ctx ctx = {};
+	unsigned int i;
+
+	trans = container_of(rcu, struct nft_trans_gc, rcu);
+	ctx.net	= read_pnet(&trans->set->net);
+
+	for (i = 0; i < trans->count; i++) {
+		elem.priv = trans->priv[i];
+		if (!nft_setelem_is_catchall(trans->set, &elem))
+			atomic_dec(&trans->set->nelems);
+
+		nf_tables_set_elem_destroy(&ctx, trans->set, elem.priv);
+	}
+
+	nft_trans_gc_destroy(trans);
+}
+
+static bool nft_trans_gc_work_done(struct nft_trans_gc *trans)
+{
+	struct nftables_pernet *nft_net;
+	struct nft_ctx ctx = {};
+
+	nft_net = nft_pernet(trans->net);
+
+	mutex_lock(&nft_net->commit_mutex);
+
+	/* Check for race with transaction, otherwise this batch refers to
+	 * stale objects that might not be there anymore. Skip transaction if
+	 * set has been destroyed from control plane transaction in case gc
+	 * worker loses race.
+	 */
+	if (READ_ONCE(nft_net->gc_seq) != trans->seq || trans->set->dead) {
+		mutex_unlock(&nft_net->commit_mutex);
+		return false;
+	}
+
+	ctx.net = trans->net;
+	ctx.table = trans->set->table;
+
+	nft_trans_gc_setelem_remove(&ctx, trans);
+	mutex_unlock(&nft_net->commit_mutex);
+
+	return true;
+}
+
+static void nft_trans_gc_work(struct work_struct *work)
+{
+	struct nft_trans_gc *trans, *next;
+	LIST_HEAD(trans_gc_list);
+
+	spin_lock(&nf_tables_gc_list_lock);
+	list_splice_init(&nf_tables_gc_list, &trans_gc_list);
+	spin_unlock(&nf_tables_gc_list_lock);
+
+	list_for_each_entry_safe(trans, next, &trans_gc_list, list) {
+		list_del(&trans->list);
+		if (!nft_trans_gc_work_done(trans)) {
+			nft_trans_gc_destroy(trans);
+			continue;
+		}
+		call_rcu(&trans->rcu, nft_trans_gc_trans_free);
+	}
+}
+
+struct nft_trans_gc *nft_trans_gc_alloc(struct nft_set *set,
+					unsigned int gc_seq, gfp_t gfp)
+{
+	struct net *net = read_pnet(&set->net);
+	struct nft_trans_gc *trans;
+
+	trans = kzalloc(sizeof(*trans), gfp);
+	if (!trans)
+		return NULL;
+
+	trans->net = maybe_get_net(net);
+	if (!trans->net) {
+		kfree(trans);
+		return NULL;
+	}
+
+	refcount_inc(&set->refs);
+	trans->set = set;
+	trans->seq = gc_seq;
+
+	return trans;
+}
+
+void nft_trans_gc_elem_add(struct nft_trans_gc *trans, void *priv)
+{
+	trans->priv[trans->count++] = priv;
+}
+
+static void nft_trans_gc_queue_work(struct nft_trans_gc *trans)
+{
+	spin_lock(&nf_tables_gc_list_lock);
+	list_add_tail(&trans->list, &nf_tables_gc_list);
+	spin_unlock(&nf_tables_gc_list_lock);
+
+	schedule_work(&trans_gc_work);
+}
+
+static int nft_trans_gc_space(struct nft_trans_gc *trans)
+{
+	return NFT_TRANS_GC_BATCHCOUNT - trans->count;
+}
+
+struct nft_trans_gc *nft_trans_gc_queue_async(struct nft_trans_gc *gc,
+					      unsigned int gc_seq, gfp_t gfp)
+{
+	struct nft_set *set;
+
+	if (nft_trans_gc_space(gc))
+		return gc;
+
+	set = gc->set;
+	nft_trans_gc_queue_work(gc);
+
+	return nft_trans_gc_alloc(set, gc_seq, gfp);
+}
+
+void nft_trans_gc_queue_async_done(struct nft_trans_gc *trans)
+{
+	if (trans->count == 0) {
+		nft_trans_gc_destroy(trans);
+		return;
+	}
+
+	nft_trans_gc_queue_work(trans);
+}
+
+struct nft_trans_gc *nft_trans_gc_queue_sync(struct nft_trans_gc *gc, gfp_t gfp)
+{
+	struct nft_set *set;
+
+	if (WARN_ON_ONCE(!lockdep_commit_lock_is_held(gc->net)))
+		return NULL;
+
+	if (nft_trans_gc_space(gc))
+		return gc;
+
+	set = gc->set;
+	call_rcu(&gc->rcu, nft_trans_gc_trans_free);
+
+	return nft_trans_gc_alloc(set, 0, gfp);
+}
+
+void nft_trans_gc_queue_sync_done(struct nft_trans_gc *trans)
+{
+	WARN_ON_ONCE(!lockdep_commit_lock_is_held(trans->net));
+
+	if (trans->count == 0) {
+		nft_trans_gc_destroy(trans);
+		return;
+	}
+
+	call_rcu(&trans->rcu, nft_trans_gc_trans_free);
+}
+
+static struct nft_trans_gc *nft_trans_gc_catchall(struct nft_trans_gc *gc,
+						  unsigned int gc_seq,
+						  bool sync)
+{
+	struct nft_set_elem_catchall *catchall;
+	const struct nft_set *set = gc->set;
+	struct nft_set_ext *ext;
+
+	list_for_each_entry_rcu(catchall, &set->catchall_list, list) {
+		ext = nft_set_elem_ext(set, catchall->elem);
+
+		if (!nft_set_elem_expired(ext))
+			continue;
+		if (nft_set_elem_is_dead(ext))
+			goto dead_elem;
+
+		nft_set_elem_dead(ext);
+dead_elem:
+		if (sync)
+			gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
+		else
+			gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
+
+		if (!gc)
+			return NULL;
+
+		nft_trans_gc_elem_add(gc, catchall->elem);
+	}
+
+	return gc;
+}
+
+struct nft_trans_gc *nft_trans_gc_catchall_async(struct nft_trans_gc *gc,
+						 unsigned int gc_seq)
+{
+	return nft_trans_gc_catchall(gc, gc_seq, false);
+}
+
+struct nft_trans_gc *nft_trans_gc_catchall_sync(struct nft_trans_gc *gc)
+{
+	return nft_trans_gc_catchall(gc, 0, true);
+}
+
 static void nf_tables_module_autoload_cleanup(struct net *net)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
@@ -9049,15 +9242,31 @@
 	}
 }
 
+static unsigned int nft_gc_seq_begin(struct nftables_pernet *nft_net)
+{
+	unsigned int gc_seq;
+
+	/* Bump gc counter, it becomes odd, this is the busy mark. */
+	gc_seq = READ_ONCE(nft_net->gc_seq);
+	WRITE_ONCE(nft_net->gc_seq, ++gc_seq);
+
+	return gc_seq;
+}
+
+static void nft_gc_seq_end(struct nftables_pernet *nft_net, unsigned int gc_seq)
+{
+	WRITE_ONCE(nft_net->gc_seq, ++gc_seq);
+}
+
 static int nf_tables_commit(struct net *net, struct sk_buff *skb)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
 	struct nft_trans *trans, *next;
+	unsigned int base_seq, gc_seq;
 	LIST_HEAD(set_update_list);
 	struct nft_trans_elem *te;
 	struct nft_chain *chain;
 	struct nft_table *table;
-	unsigned int base_seq;
 	LIST_HEAD(adl);
 	int err;
 
@@ -9134,6 +9343,8 @@
 
 	WRITE_ONCE(nft_net->base_seq, base_seq);
 
+	gc_seq = nft_gc_seq_begin(nft_net);
+
 	/* step 3. Start new generation, rules_gen_X now in use. */
 	net->nft.gencursor = nft_gencursor_next(net);
 
@@ -9222,6 +9433,7 @@
 			nft_trans_destroy(trans);
 			break;
 		case NFT_MSG_DELSET:
+			nft_trans_set(trans)->dead = 1;
 			list_del_rcu(&nft_trans_set(trans)->list);
 			nf_tables_set_notify(&trans->ctx, nft_trans_set(trans),
 					     NFT_MSG_DELSET, GFP_KERNEL);
@@ -9321,6 +9533,8 @@
 	nft_commit_notify(net, NETLINK_CB(skb).portid);
 	nf_tables_gen_notify(net, skb, NFT_MSG_NEWGEN);
 	nf_tables_commit_audit_log(&adl, nft_net->base_seq);
+
+	nft_gc_seq_end(nft_net, gc_seq);
 	nf_tables_commit_release(net);
 
 	return 0;
@@ -9579,7 +9793,12 @@
 			   enum nfnl_abort_action action)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
-	int ret = __nf_tables_abort(net, action);
+	unsigned int gc_seq;
+	int ret;
+
+	gc_seq = nft_gc_seq_begin(nft_net);
+	ret = __nf_tables_abort(net, action);
+	nft_gc_seq_end(nft_net, gc_seq);
 
 	mutex_unlock(&nft_net->commit_mutex);
 
@@ -10303,6 +10522,7 @@
 	struct net *net = n->net;
 	unsigned int deleted;
 	bool restart = false;
+	unsigned int gc_seq;
 
 	if (event != NETLINK_URELEASE || n->protocol != NETLINK_NETFILTER)
 		return NOTIFY_DONE;
@@ -10310,6 +10530,9 @@
 	nft_net = nft_pernet(net);
 	deleted = 0;
 	mutex_lock(&nft_net->commit_mutex);
+
+	gc_seq = nft_gc_seq_begin(nft_net);
+
 	if (!list_empty(&nf_tables_destroy_list))
 		nf_tables_trans_destroy_flush_work();
 again:
@@ -10332,6 +10555,8 @@
 		if (restart)
 			goto again;
 	}
+	nft_gc_seq_end(nft_net, gc_seq);
+
 	mutex_unlock(&nft_net->commit_mutex);
 
 	return NOTIFY_DONE;
@@ -10353,6 +10578,7 @@
 	mutex_init(&nft_net->commit_mutex);
 	nft_net->base_seq = 1;
 	nft_net->validate_state = NFT_VALIDATE_SKIP;
+	nft_net->gc_seq = 0;
 
 	return 0;
 }
@@ -10369,22 +10595,36 @@
 static void __net_exit nf_tables_exit_net(struct net *net)
 {
 	struct nftables_pernet *nft_net = nft_pernet(net);
+	unsigned int gc_seq;
 
 	mutex_lock(&nft_net->commit_mutex);
+
+	gc_seq = nft_gc_seq_begin(nft_net);
+
 	if (!list_empty(&nft_net->commit_list) ||
 	    !list_empty(&nft_net->module_list))
 		__nf_tables_abort(net, NFNL_ABORT_NONE);
+
 	__nft_release_tables(net);
+
+	nft_gc_seq_end(nft_net, gc_seq);
+
 	mutex_unlock(&nft_net->commit_mutex);
 	WARN_ON_ONCE(!list_empty(&nft_net->tables));
 	WARN_ON_ONCE(!list_empty(&nft_net->module_list));
 	WARN_ON_ONCE(!list_empty(&nft_net->notify_list));
 }
 
+static void nf_tables_exit_batch(struct list_head *net_exit_list)
+{
+	flush_work(&trans_gc_work);
+}
+
 static struct pernet_operations nf_tables_net_ops = {
 	.init		= nf_tables_init_net,
 	.pre_exit	= nf_tables_pre_exit_net,
 	.exit		= nf_tables_exit_net,
+	.exit_batch	= nf_tables_exit_batch,
 	.id		= &nf_tables_net_id,
 	.size		= sizeof(struct nftables_pernet),
 };
@@ -10456,6 +10696,7 @@
 	nft_chain_filter_fini();
 	nft_chain_route_fini();
 	unregister_pernet_subsys(&nf_tables_net_ops);
+	cancel_work_sync(&trans_gc_work);
 	cancel_work_sync(&trans_destroy_work);
 	rcu_barrier();
 	rhltable_destroy(&nft_objname_ht);
diff --git a/net/netfilter/nft_set_hash.c b/net/netfilter/nft_set_hash.c
index 0b73cb0..2013de9 100644
--- a/net/netfilter/nft_set_hash.c
+++ b/net/netfilter/nft_set_hash.c
@@ -59,6 +59,8 @@
 
 	if (memcmp(nft_set_ext_key(&he->ext), x->key, x->set->klen))
 		return 1;
+	if (nft_set_elem_is_dead(&he->ext))
+		return 1;
 	if (nft_set_elem_expired(&he->ext))
 		return 1;
 	if (!nft_set_elem_active(&he->ext, x->genmask))
@@ -188,7 +190,6 @@
 	struct nft_rhash_elem *he = elem->priv;
 
 	nft_set_elem_change_active(net, set, &he->ext);
-	nft_set_elem_clear_busy(&he->ext);
 }
 
 static bool nft_rhash_flush(const struct net *net,
@@ -196,12 +197,9 @@
 {
 	struct nft_rhash_elem *he = priv;
 
-	if (!nft_set_elem_mark_busy(&he->ext) ||
-	    !nft_is_active(net, &he->ext)) {
-		nft_set_elem_change_active(net, set, &he->ext);
-		return true;
-	}
-	return false;
+	nft_set_elem_change_active(net, set, &he->ext);
+
+	return true;
 }
 
 static void *nft_rhash_deactivate(const struct net *net,
@@ -218,9 +216,8 @@
 
 	rcu_read_lock();
 	he = rhashtable_lookup(&priv->ht, &arg, nft_rhash_params);
-	if (he != NULL &&
-	    !nft_rhash_flush(net, set, he))
-		he = NULL;
+	if (he)
+		nft_set_elem_change_active(net, set, &he->ext);
 
 	rcu_read_unlock();
 
@@ -252,7 +249,9 @@
 	if (he == NULL)
 		return false;
 
-	return rhashtable_remove_fast(&priv->ht, &he->node, nft_rhash_params) == 0;
+	nft_set_elem_dead(&he->ext);
+
+	return true;
 }
 
 static void nft_rhash_walk(const struct nft_ctx *ctx, struct nft_set *set,
@@ -278,8 +277,6 @@
 
 		if (iter->count < iter->skip)
 			goto cont;
-		if (nft_set_elem_expired(&he->ext))
-			goto cont;
 		if (!nft_set_elem_active(&he->ext, iter->genmask))
 			goto cont;
 
@@ -314,25 +311,48 @@
 
 static void nft_rhash_gc(struct work_struct *work)
 {
+	struct nftables_pernet *nft_net;
 	struct nft_set *set;
 	struct nft_rhash_elem *he;
 	struct nft_rhash *priv;
-	struct nft_set_gc_batch *gcb = NULL;
 	struct rhashtable_iter hti;
+	struct nft_trans_gc *gc;
+	struct net *net;
+	u32 gc_seq;
 
 	priv = container_of(work, struct nft_rhash, gc_work.work);
 	set  = nft_set_container_of(priv);
+	net  = read_pnet(&set->net);
+	nft_net = nft_pernet(net);
+	gc_seq = READ_ONCE(nft_net->gc_seq);
+
+	if (nft_set_gc_is_pending(set))
+		goto done;
+
+	gc = nft_trans_gc_alloc(set, gc_seq, GFP_KERNEL);
+	if (!gc)
+		goto done;
 
 	rhashtable_walk_enter(&priv->ht, &hti);
 	rhashtable_walk_start(&hti);
 
 	while ((he = rhashtable_walk_next(&hti))) {
 		if (IS_ERR(he)) {
-			if (PTR_ERR(he) != -EAGAIN)
-				break;
-			continue;
+			nft_trans_gc_destroy(gc);
+			gc = NULL;
+			goto try_later;
 		}
 
+		/* Ruleset has been updated, try later. */
+		if (READ_ONCE(nft_net->gc_seq) != gc_seq) {
+			nft_trans_gc_destroy(gc);
+			gc = NULL;
+			goto try_later;
+		}
+
+		if (nft_set_elem_is_dead(&he->ext))
+			goto dead_elem;
+
 		if (nft_set_ext_exists(&he->ext, NFT_SET_EXT_EXPRESSIONS) &&
 		    nft_rhash_expr_needs_gc_run(set, &he->ext))
 			goto needs_gc_run;
@@ -340,26 +360,26 @@
 		if (!nft_set_elem_expired(&he->ext))
 			continue;
 needs_gc_run:
-		if (nft_set_elem_mark_busy(&he->ext))
-			continue;
+		nft_set_elem_dead(&he->ext);
+dead_elem:
+		gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
+		if (!gc)
+			goto try_later;
 
-		gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
-		if (gcb == NULL)
-			break;
-		rhashtable_remove_fast(&priv->ht, &he->node, nft_rhash_params);
-		atomic_dec(&set->nelems);
-		nft_set_gc_batch_add(gcb, he);
+		nft_trans_gc_elem_add(gc, he);
 	}
+
+	gc = nft_trans_gc_catchall_async(gc, gc_seq);
+
+try_later:
+	/* catchall list iteration requires rcu read side lock. */
 	rhashtable_walk_stop(&hti);
 	rhashtable_walk_exit(&hti);
 
-	he = nft_set_catchall_gc(set);
-	if (he) {
-		gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
-		if (gcb)
-			nft_set_gc_batch_add(gcb, he);
-	}
-	nft_set_gc_batch_complete(gcb);
+	if (gc)
+		nft_trans_gc_queue_async_done(gc);
+
+done:
 	queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
 			   nft_set_gc_interval(set));
 }
@@ -394,7 +414,7 @@
 		return err;
 
 	INIT_DEFERRABLE_WORK(&priv->gc_work, nft_rhash_gc);
-	if (set->flags & NFT_SET_TIMEOUT)
+	if (set->flags & (NFT_SET_TIMEOUT | NFT_SET_EVAL))
 		nft_rhash_gc_init(set);
 
 	return 0;
@@ -422,7 +442,6 @@
 	};
 
 	cancel_delayed_work_sync(&priv->gc_work);
-	rcu_barrier();
 	rhashtable_free_and_destroy(&priv->ht, nft_rhash_elem_destroy,
 				    (void *)&rhash_ctx);
 }
diff --git a/net/netfilter/nft_set_pipapo.c b/net/netfilter/nft_set_pipapo.c
index 8c16681..83f5f27 100644
--- a/net/netfilter/nft_set_pipapo.c
+++ b/net/netfilter/nft_set_pipapo.c
@@ -566,8 +566,9 @@
 			goto out;
 
 		if (last) {
-			if (nft_set_elem_expired(&f->mt[b].e->ext) ||
-			    (genmask &&
+			if (nft_set_elem_expired(&f->mt[b].e->ext))
+				goto next_match;
+			if ((genmask &&
 			     !nft_set_elem_active(&f->mt[b].e->ext, genmask)))
 				goto next_match;
 
@@ -602,7 +603,7 @@
 			    const struct nft_set_elem *elem, unsigned int flags)
 {
 	return pipapo_get(net, set, (const u8 *)elem->key.val.data,
-			  nft_genmask_cur(net));
+			 nft_genmask_cur(net));
 }
 
 /**
@@ -1536,16 +1537,34 @@
 	}
 }
 
+static void nft_pipapo_gc_deactivate(struct net *net, struct nft_set *set,
+				     struct nft_pipapo_elem *e)
+
+{
+	struct nft_set_elem elem = {
+		.priv	= e,
+	};
+
+	nft_setelem_data_deactivate(net, set, &elem);
+}
+
 /**
  * pipapo_gc() - Drop expired entries from set, destroy start and end elements
  * @set:	nftables API set representation
  * @m:		Matching data
  */
-static void pipapo_gc(const struct nft_set *set, struct nft_pipapo_match *m)
+static void pipapo_gc(const struct nft_set *_set, struct nft_pipapo_match *m)
 {
+	struct nft_set *set = (struct nft_set *) _set;
 	struct nft_pipapo *priv = nft_set_priv(set);
+	struct net *net = read_pnet(&set->net);
 	int rules_f0, first_rule = 0;
 	struct nft_pipapo_elem *e;
+	struct nft_trans_gc *gc;
+
+	gc = nft_trans_gc_alloc(set, 0, GFP_KERNEL);
+	if (!gc)
+		return;
 
 	while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) {
 		union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS];
@@ -1569,13 +1588,20 @@
 		f--;
 		i--;
 		e = f->mt[rulemap[i].to].e;
-		if (nft_set_elem_expired(&e->ext) &&
-		    !nft_set_elem_mark_busy(&e->ext)) {
-			priv->dirty = true;
-			pipapo_drop(m, rulemap);
 
-			rcu_barrier();
-			nft_set_elem_destroy(set, e, true);
+		/* synchronous gc never fails, there is no need to set on
+		 * NFT_SET_ELEM_DEAD_BIT.
+		 */
+		if (nft_set_elem_expired(&e->ext)) {
+			priv->dirty = true;
+
+			gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
+			if (!gc)
+				return;
+
+			nft_pipapo_gc_deactivate(net, set, e);
+			pipapo_drop(m, rulemap);
+			nft_trans_gc_elem_add(gc, e);
 
 			/* And check again current first rule, which is now the
 			 * first we haven't checked.
@@ -1585,11 +1611,11 @@
 		}
 	}
 
-	e = nft_set_catchall_gc(set);
-	if (e)
-		nft_set_elem_destroy(set, e, true);
-
-	priv->last_gc = jiffies;
+	gc = nft_trans_gc_catchall_sync(gc);
+	if (gc) {
+		nft_trans_gc_queue_sync_done(gc);
+		priv->last_gc = jiffies;
+	}
 }
 
 /**
@@ -1718,14 +1744,9 @@
 				const struct nft_set *set,
 				const struct nft_set_elem *elem)
 {
-	struct nft_pipapo_elem *e;
-
-	e = pipapo_get(net, set, (const u8 *)elem->key.val.data, 0);
-	if (IS_ERR(e))
-		return;
+	struct nft_pipapo_elem *e = elem->priv;
 
 	nft_set_elem_change_active(net, set, &e->ext);
-	nft_set_elem_clear_busy(&e->ext);
 }
 
 /**
@@ -1937,10 +1958,6 @@
 
 	data = (const u8 *)nft_set_ext_key(&e->ext);
 
-	e = pipapo_get(net, set, data, 0);
-	if (IS_ERR(e))
-		return;
-
 	while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) {
 		union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS];
 		const u8 *match_start, *match_end;
@@ -2024,8 +2041,6 @@
 			goto cont;
 
 		e = f->mt[r].e;
-		if (nft_set_elem_expired(&e->ext))
-			goto cont;
 
 		elem.priv = e;
 
diff --git a/net/netfilter/nft_set_rbtree.c b/net/netfilter/nft_set_rbtree.c
index 8d73fff..487572d 100644
--- a/net/netfilter/nft_set_rbtree.c
+++ b/net/netfilter/nft_set_rbtree.c
@@ -46,6 +46,12 @@
 		      set->klen);
 }
 
+static bool nft_rbtree_elem_expired(const struct nft_rbtree_elem *rbe)
+{
+	return nft_set_elem_expired(&rbe->ext) ||
+	       nft_set_elem_is_dead(&rbe->ext);
+}
+
 static bool __nft_rbtree_lookup(const struct net *net, const struct nft_set *set,
 				const u32 *key, const struct nft_set_ext **ext,
 				unsigned int seq)
@@ -80,7 +86,7 @@
 				continue;
 			}
 
-			if (nft_set_elem_expired(&rbe->ext))
+			if (nft_rbtree_elem_expired(rbe))
 				return false;
 
 			if (nft_rbtree_interval_end(rbe)) {
@@ -98,7 +104,7 @@
 
 	if (set->flags & NFT_SET_INTERVAL && interval != NULL &&
 	    nft_set_elem_active(&interval->ext, genmask) &&
-	    !nft_set_elem_expired(&interval->ext) &&
+	    !nft_rbtree_elem_expired(interval) &&
 	    nft_rbtree_interval_start(interval)) {
 		*ext = &interval->ext;
 		return true;
@@ -215,6 +221,18 @@
 	return rbe;
 }
 
+static void nft_rbtree_gc_remove(struct net *net, struct nft_set *set,
+				 struct nft_rbtree *priv,
+				 struct nft_rbtree_elem *rbe)
+{
+	struct nft_set_elem elem = {
+		.priv	= rbe,
+	};
+
+	nft_setelem_data_deactivate(net, set, &elem);
+	rb_erase(&rbe->node, &priv->root);
+}
+
 static int nft_rbtree_gc_elem(const struct nft_set *__set,
 			      struct nft_rbtree *priv,
 			      struct nft_rbtree_elem *rbe,
@@ -222,11 +240,12 @@
 {
 	struct nft_set *set = (struct nft_set *)__set;
 	struct rb_node *prev = rb_prev(&rbe->node);
+	struct net *net = read_pnet(&set->net);
 	struct nft_rbtree_elem *rbe_prev;
-	struct nft_set_gc_batch *gcb;
+	struct nft_trans_gc *gc;
 
-	gcb = nft_set_gc_batch_check(set, NULL, GFP_ATOMIC);
-	if (!gcb)
+	gc = nft_trans_gc_alloc(set, 0, GFP_ATOMIC);
+	if (!gc)
 		return -ENOMEM;
 
 	/* search for end interval coming before this element.
@@ -244,17 +263,28 @@
 
 	if (prev) {
 		rbe_prev = rb_entry(prev, struct nft_rbtree_elem, node);
+		nft_rbtree_gc_remove(net, set, priv, rbe_prev);
 
-		rb_erase(&rbe_prev->node, &priv->root);
-		atomic_dec(&set->nelems);
-		nft_set_gc_batch_add(gcb, rbe_prev);
+		/* There is always room in this trans gc for this element,
+		 * memory allocation never actually happens, hence, the warning
+		 * splat in such case. No need to set NFT_SET_ELEM_DEAD_BIT,
+		 * this is synchronous gc which never fails.
+		 */
+		gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
+		if (WARN_ON_ONCE(!gc))
+			return -ENOMEM;
+
+		nft_trans_gc_elem_add(gc, rbe_prev);
 	}
 
-	rb_erase(&rbe->node, &priv->root);
-	atomic_dec(&set->nelems);
+	nft_rbtree_gc_remove(net, set, priv, rbe);
+	gc = nft_trans_gc_queue_sync(gc, GFP_ATOMIC);
+	if (WARN_ON_ONCE(!gc))
+		return -ENOMEM;
 
-	nft_set_gc_batch_add(gcb, rbe);
-	nft_set_gc_batch_complete(gcb);
+	nft_trans_gc_elem_add(gc, rbe);
+
+	nft_trans_gc_queue_sync_done(gc);
 
 	return 0;
 }
@@ -282,6 +312,7 @@
 	struct nft_rbtree_elem *rbe, *rbe_le = NULL, *rbe_ge = NULL;
 	struct rb_node *node, *next, *parent, **p, *first = NULL;
 	struct nft_rbtree *priv = nft_set_priv(set);
+	u8 cur_genmask = nft_genmask_cur(net);
 	u8 genmask = nft_genmask_next(net);
 	int d, err;
 
@@ -327,8 +358,11 @@
 		if (!nft_set_elem_active(&rbe->ext, genmask))
 			continue;
 
-		/* perform garbage collection to avoid bogus overlap reports. */
-		if (nft_set_elem_expired(&rbe->ext)) {
+		/* perform garbage collection to avoid bogus overlap reports
+		 * but skip new elements in this transaction.
+		 */
+		if (nft_set_elem_expired(&rbe->ext) &&
+		    nft_set_elem_active(&rbe->ext, cur_genmask)) {
 			err = nft_rbtree_gc_elem(set, priv, rbe, genmask);
 			if (err < 0)
 				return err;
@@ -482,7 +516,6 @@
 	struct nft_rbtree_elem *rbe = elem->priv;
 
 	nft_set_elem_change_active(net, set, &rbe->ext);
-	nft_set_elem_clear_busy(&rbe->ext);
 }
 
 static bool nft_rbtree_flush(const struct net *net,
@@ -490,12 +523,9 @@
 {
 	struct nft_rbtree_elem *rbe = priv;
 
-	if (!nft_set_elem_mark_busy(&rbe->ext) ||
-	    !nft_is_active(net, &rbe->ext)) {
-		nft_set_elem_change_active(net, set, &rbe->ext);
-		return true;
-	}
-	return false;
+	nft_set_elem_change_active(net, set, &rbe->ext);
+
+	return true;
 }
 
 static void *nft_rbtree_deactivate(const struct net *net,
@@ -552,8 +582,6 @@
 
 		if (iter->count < iter->skip)
 			goto cont;
-		if (nft_set_elem_expired(&rbe->ext))
-			goto cont;
 		if (!nft_set_elem_active(&rbe->ext, iter->genmask))
 			goto cont;
 
@@ -572,26 +600,42 @@
 
 static void nft_rbtree_gc(struct work_struct *work)
 {
-	struct nft_rbtree_elem *rbe, *rbe_end = NULL, *rbe_prev = NULL;
-	struct nft_set_gc_batch *gcb = NULL;
+	struct nft_rbtree_elem *rbe, *rbe_end = NULL;
+	struct nftables_pernet *nft_net;
 	struct nft_rbtree *priv;
+	struct nft_trans_gc *gc;
 	struct rb_node *node;
 	struct nft_set *set;
+	unsigned int gc_seq;
 	struct net *net;
-	u8 genmask;
 
 	priv = container_of(work, struct nft_rbtree, gc_work.work);
 	set  = nft_set_container_of(priv);
 	net  = read_pnet(&set->net);
-	genmask = nft_genmask_cur(net);
+	nft_net = nft_pernet(net);
+	gc_seq  = READ_ONCE(nft_net->gc_seq);
 
-	write_lock_bh(&priv->lock);
-	write_seqcount_begin(&priv->count);
+	if (nft_set_gc_is_pending(set))
+		goto done;
+
+	gc = nft_trans_gc_alloc(set, gc_seq, GFP_KERNEL);
+	if (!gc)
+		goto done;
+
+	read_lock_bh(&priv->lock);
 	for (node = rb_first(&priv->root); node != NULL; node = rb_next(node)) {
+
+		/* Ruleset has been updated, try later. */
+		if (READ_ONCE(nft_net->gc_seq) != gc_seq) {
+			nft_trans_gc_destroy(gc);
+			gc = NULL;
+			goto try_later;
+		}
+
 		rbe = rb_entry(node, struct nft_rbtree_elem, node);
 
-		if (!nft_set_elem_active(&rbe->ext, genmask))
-			continue;
+		if (nft_set_elem_is_dead(&rbe->ext))
+			goto dead_elem;
 
 		/* elements are reversed in the rbtree for historical reasons,
 		 * from highest to lowest value, that is why end element is
@@ -604,46 +648,35 @@
 		if (!nft_set_elem_expired(&rbe->ext))
 			continue;
 
-		if (nft_set_elem_mark_busy(&rbe->ext)) {
-			rbe_end = NULL;
+		nft_set_elem_dead(&rbe->ext);
+
+		if (!rbe_end)
 			continue;
-		}
 
-		if (rbe_prev) {
-			rb_erase(&rbe_prev->node, &priv->root);
-			rbe_prev = NULL;
-		}
-		gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
-		if (!gcb)
-			break;
+		nft_set_elem_dead(&rbe_end->ext);
 
-		atomic_dec(&set->nelems);
-		nft_set_gc_batch_add(gcb, rbe);
-		rbe_prev = rbe;
+		gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
+		if (!gc)
+			goto try_later;
 
-		if (rbe_end) {
-			atomic_dec(&set->nelems);
-			nft_set_gc_batch_add(gcb, rbe_end);
-			rb_erase(&rbe_end->node, &priv->root);
-			rbe_end = NULL;
-		}
-		node = rb_next(node);
-		if (!node)
-			break;
+		nft_trans_gc_elem_add(gc, rbe_end);
+		rbe_end = NULL;
+dead_elem:
+		gc = nft_trans_gc_queue_async(gc, gc_seq, GFP_ATOMIC);
+		if (!gc)
+			goto try_later;
+
+		nft_trans_gc_elem_add(gc, rbe);
 	}
-	if (rbe_prev)
-		rb_erase(&rbe_prev->node, &priv->root);
-	write_seqcount_end(&priv->count);
-	write_unlock_bh(&priv->lock);
 
-	rbe = nft_set_catchall_gc(set);
-	if (rbe) {
-		gcb = nft_set_gc_batch_check(set, gcb, GFP_ATOMIC);
-		if (gcb)
-			nft_set_gc_batch_add(gcb, rbe);
-	}
-	nft_set_gc_batch_complete(gcb);
+	gc = nft_trans_gc_catchall_async(gc, gc_seq);
 
+try_later:
+	read_unlock_bh(&priv->lock);
+
+	if (gc)
+		nft_trans_gc_queue_async_done(gc);
+done:
 	queue_delayed_work(system_power_efficient_wq, &priv->gc_work,
 			   nft_set_gc_interval(set));
 }