[PATCH net-next v3 0/4] vsock: consolidate acceptq accounting into core helpers

[PATCH net-next v3 0/4] vsock: consolidate acceptq accounting into core helpers

[Raf Dickson]

These patches follow up on commit c05fa14db43e
("vsock/vmci: fix sk_ack_backlog leak on failed handshake")
by consolidating sk_acceptq_added() and sk_acceptq_removed() into
the core vsock helpers so transports cannot forget them.

Changes since v2:
  - Add vsock_pending_to_accept() helper for the vmci pending->accept
    transition, avoiding a double sk_acceptq_added() (Stefano Garzarella)
  - Split into 4 patches for bisectability (Stefano Garzarella)
  - Fold sk_acceptq_added() into vsock_add_pending() as a separate patch

Link: https://lore.kernel.org/netdev/20260611021317.69362-1-rafdog35@gmail.com/

Raf Dickson (4):
  vsock: introduce vsock_pending_to_accept() helper
  vsock: fold sk_acceptq_added() into vsock_add_pending()
  vsock: fold sk_acceptq_added() into vsock_enqueue_accept()
  vsock: fold sk_acceptq_removed() into vsock_remove_pending()

 include/net/af_vsock.h                  |  1 +
 net/vmw_vsock/af_vsock.c                | 14 +++++++++++++-
 net/vmw_vsock/hyperv_transport.c        |  1 -
 net/vmw_vsock/virtio_transport_common.c |  1 -
 net/vmw_vsock/vmci_transport.c          |  8 ++------
 5 files changed, 16 insertions(+), 9 deletions(-)

-- 
2.54.0

[PATCH net-next v3 1/4] vsock: introduce vsock_pending_to_accept() helper

[Raf Dickson]

Add vsock_pending_to_accept() to move a socket directly from the
pending list to the accept queue in a single operation, avoiding
the sock_put/sock_hold dance and the sk_acceptq_removed()/
sk_acceptq_added() pair that would otherwise be needed when
calling vsock_remove_pending() followed by vsock_enqueue_accept().

Use it in vmci_transport_recv_connecting_server() where a completed
handshake transitions the socket from pending to accept queue.

Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Raf Dickson <rafdog35@gmail.com>
---
 include/net/af_vsock.h         |  1 +
 net/vmw_vsock/af_vsock.c       | 10 ++++++++++
 net/vmw_vsock/vmci_transport.c |  3 +--
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 4e40063ada..30046a3c20 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -220,6 +220,7 @@ static inline bool __vsock_in_connected_table(struct vsock_sock *vsk)
 void vsock_add_pending(struct sock *listener, struct sock *pending);
 void vsock_remove_pending(struct sock *listener, struct sock *pending);
 void vsock_enqueue_accept(struct sock *listener, struct sock *connected);
+void vsock_pending_to_accept(struct sock *listener, struct sock *pending);
 void vsock_insert_connected(struct vsock_sock *vsk);
 void vsock_remove_bound(struct vsock_sock *vsk);
 void vsock_remove_connected(struct vsock_sock *vsk);
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 2ce1063d4a..1f94f0d44c 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -496,6 +496,16 @@ void vsock_remove_pending(struct sock *listener, struct sock *pending)
 }
 EXPORT_SYMBOL_GPL(vsock_remove_pending);
 
+void vsock_pending_to_accept(struct sock *listener, struct sock *pending)
+{
+	struct vsock_sock *vpending = vsock_sk(pending);
+	struct vsock_sock *vlistener = vsock_sk(listener);
+
+	list_del_init(&vpending->pending_links);
+	list_add_tail(&vpending->accept_queue, &vlistener->accept_queue);
+}
+EXPORT_SYMBOL_GPL(vsock_pending_to_accept);
+
 void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 {
 	struct vsock_sock *vlistener;
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 91516488a7..635ebf9da4 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -1258,8 +1258,7 @@ vmci_transport_recv_connecting_server(struct sock *listener,
 	 * listener's pending list to the accept queue so callers of accept()
 	 * can find it.
 	 */
-	vsock_remove_pending(listener, pending);
-	vsock_enqueue_accept(listener, pending);
+	vsock_pending_to_accept(listener, pending);
 
 	/* Callers of accept() will be waiting on the listening socket, not
 	 * the pending socket.
-- 
2.54.0

[PATCH net-next v3 2/4] vsock: fold sk_acceptq_added() into vsock_add_pending()

[Raf Dickson]

Move sk_acceptq_added() into vsock_add_pending() so callers cannot
forget it. vmci is the only transport using the pending list and
is updated accordingly.

Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Raf Dickson <rafdog35@gmail.com>
---
 net/vmw_vsock/af_vsock.c       | 1 +
 net/vmw_vsock/vmci_transport.c | 1 -
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 1f94f0d44c..6cfa89b6f3 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -483,6 +483,7 @@ void vsock_add_pending(struct sock *listener, struct sock *pending)
 	sock_hold(pending);
 	sock_hold(listener);
 	list_add_tail(&vpending->pending_links, &vlistener->pending_links);
+	sk_acceptq_added(listener);
 }
 EXPORT_SYMBOL_GPL(vsock_add_pending);
 
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 635ebf9da4..c2db016cca 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -1109,7 +1109,6 @@ static int vmci_transport_recv_listen(struct sock *sk,
 	}
 
 	vsock_add_pending(sk, pending);
-	sk_acceptq_added(sk);
 
 	pending->sk_state = TCP_SYN_SENT;
 	vmci_trans(vpending)->produce_size =
-- 
2.54.0

[PATCH net-next v3 3/4] vsock: fold sk_acceptq_added() into vsock_enqueue_accept()

[Raf Dickson]

virtio and hyperv call sk_acceptq_added() immediately before
vsock_enqueue_accept(). Move the call into vsock_enqueue_accept()
itself so callers cannot forget it and the accounting is consistent.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Raf Dickson <rafdog35@gmail.com>
---
 net/vmw_vsock/af_vsock.c                | 1 +
 net/vmw_vsock/hyperv_transport.c        | 1 -
 net/vmw_vsock/virtio_transport_common.c | 1 -
 3 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 6cfa89b6f3..24916dd4e9 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -518,6 +518,7 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
 	sock_hold(connected);
 	sock_hold(listener);
 	list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
+	sk_acceptq_added(listener);
 }
 EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
 
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index b3394946b2..0de8148877 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -410,7 +410,6 @@ static void hvs_open_connection(struct vmbus_channel *chan)
 
 	if (conn_from_host) {
 		new->sk_state = TCP_ESTABLISHED;
-		sk_acceptq_added(sk);
 
 		hvs_new->vm_srv_id = *if_type;
 		hvs_new->host_srv_id = *if_instance;
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index b10666937c..4a39d48db9 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1582,7 +1582,6 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
 		return ret;
 	}
 
-	sk_acceptq_added(sk);
 	if (virtio_transport_space_update(child, skb))
 		child->sk_write_space(child);
 
-- 
2.54.0

[PATCH net-next v3 4/4] vsock: fold sk_acceptq_removed() into vsock_remove_pending()

[Raf Dickson]

Callers of vsock_remove_pending() must also call sk_acceptq_removed()
to keep sk_ack_backlog consistent. Move the call into
vsock_remove_pending() itself to make it automatic and prevent future
callers from forgetting it.

Suggested-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Raf Dickson <rafdog35@gmail.com>
---
 net/vmw_vsock/af_vsock.c       | 2 +-
 net/vmw_vsock/vmci_transport.c | 4 +---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 24916dd4e9..4a7d6d247a 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -494,6 +494,7 @@ void vsock_remove_pending(struct sock *listener, struct sock *pending)
 	list_del_init(&vpending->pending_links);
 	sock_put(listener);
 	sock_put(pending);
+	sk_acceptq_removed(listener);
 }
 EXPORT_SYMBOL_GPL(vsock_remove_pending);
 
@@ -773,7 +774,6 @@ static void vsock_pending_work(struct work_struct *work)
 	if (vsock_is_pending(sk)) {
 		vsock_remove_pending(listener, sk);
 
-		sk_acceptq_removed(listener);
 	} else if (!vsk->rejected) {
 		/* We are not on the pending list and accept() did not reject
 		 * us, so we must have been accepted by our user process.  We
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index c2db016cca..3e6445f4e1 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -980,10 +980,8 @@ static int vmci_transport_recv_listen(struct sock *sk,
 			err = -EINVAL;
 		}
 
-		if (err < 0) {
+		if (err < 0)
 			vsock_remove_pending(sk, pending);
-			sk_acceptq_removed(sk);
-		}
 
 		release_sock(pending);
 		vmci_transport_release_pending(pending);
-- 
2.54.0