On Fri, Jan 10, 2025 at 09:35:09AM +0100, Stefano Garzarella wrote:

During virtio_transport_release() we can schedule a delayed work to perform the closing of the socket before destruction.

The destructor is called either when the socket is really destroyed (reference counter to zero), or it can also be called when we are de-assigning the transport.

In the former case, we are sure the delayed work has completed, because it holds a reference until it completes, so the destructor will definitely be called after the delayed work is finished. But in the latter case, the destructor is called by AF_VSOCK core, just after the release(), so there may still be delayed work scheduled.

Refactor the code, moving the code to delete the close work already in the do_close() to a new function. Invoke it during destruction to make sure we don't leave any pending work.

Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") Cc: stable@vger.kernel.org Reported-by: Hyunwoo Kim v4bel@theori.io Closes: https://lore.kernel.org/netdev/Z37Sh+utS+iV3+eb@v4bel-B760M-AORUS-ELITE-AX/ Signed-off-by: Stefano Garzarella sgarzare@redhat.com

---

net/vmw_vsock/virtio_transport_common.c | 29 ++++++++++++++++++------- 1 file changed, 21 insertions(+), 8 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 51a494b69be8..7f7de6d88096 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -26,6 +26,9 @@ /* Threshold for detecting small packets to copy */ #define GOOD_COPY_LEN 128 +static void virtio_transport_cancel_close_work(struct vsock_sock *vsk,

• 			       bool cancel_timeout);
  

static const struct virtio_transport * virtio_transport_get_ops(struct vsock_sock *vsk) { @@ -1109,6 +1112,8 @@ void virtio_transport_destruct(struct vsock_sock *vsk) { struct virtio_vsock_sock *vvs = vsk->trans;

• virtio_transport_cancel_close_work(vsk, true);
• kfree(vvs); vsk->trans = NULL;

} @@ -1204,17 +1209,11 @@ static void virtio_transport_wait_close(struct sock *sk, long timeout) } } -static void virtio_transport_do_close(struct vsock_sock *vsk,

• 		      bool cancel_timeout)
  

+static void virtio_transport_cancel_close_work(struct vsock_sock *vsk,

• 			       bool cancel_timeout)
  

{ struct sock *sk = sk_vsock(vsk);

• sock_set_flag(sk, SOCK_DONE);
• vsk->peer_shutdown = SHUTDOWN_MASK;
• if (vsock_stream_has_data(vsk) <= 0)

• sk->sk_state = TCP_CLOSING;
  

• sk->sk_state_change(sk);
• if (vsk->close_work_scheduled && (!cancel_timeout || cancel_delayed_work(&vsk->close_work))) { vsk->close_work_scheduled = false;

@@ -1226,6 +1225,20 @@ static void virtio_transport_do_close(struct vsock_sock *vsk, } } +static void virtio_transport_do_close(struct vsock_sock *vsk,

• 		      bool cancel_timeout)
  

+{

• struct sock *sk = sk_vsock(vsk);
• sock_set_flag(sk, SOCK_DONE);
• vsk->peer_shutdown = SHUTDOWN_MASK;
• if (vsock_stream_has_data(vsk) <= 0)

• sk->sk_state = TCP_CLOSING;
  

• sk->sk_state_change(sk);
• virtio_transport_cancel_close_work(vsk, cancel_timeout);

+}

static void virtio_transport_close_timeout(struct work_struct *work) { struct vsock_sock *vsk = -- 2.47.1

The two scenarios I presented have been resolved.

Tested-by: Hyunwoo Kim v4bel@theori.io

Regards, Hyunwoo Kim