Re: [PATCH net-next v11 04/13] virtio: set skb owner of virtio_transport_reset_no_sock() reply

[Stefano Garzarella]

On Thu, Nov 20, 2025 at 09:44:36PM -0800, Bobby Eshleman wrote:
> From: Bobby Eshleman <bobbyeshleman@xxxxxxxx>
>
> Associate reply packets with the sending socket. When vsock must reply
> with an RST packet and there exists a sending socket (e.g., for
> loopback), setting the skb owner to the socket correctly handles
> reference counting between the skb and sk (i.e., the sk stays alive
> until the skb is freed).
>
> This allows the net namespace to be used for socket lookups for the
> duration of the reply skb's lifetime, preventing race conditions between
> the namespace lifecycle and vsock socket search using the namespace
> pointer.
>
> Signed-off-by: Bobby Eshleman <bobbyeshleman@xxxxxxxx>
> ---
> Changes in v11:
> - move before adding to netns support (Stefano)
>
> Changes in v10:
> - break this out into its own patch for easy revert (Stefano)
> ---
> net/vmw_vsock/virtio_transport_common.c | 6 ++++++
> 1 file changed, 6 insertions(+)

Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>

> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index dcc8a1d5851e..675eb9d83549 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -1165,6 +1165,12 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
> 		.op = VIRTIO_VSOCK_OP_RST,
> 		.type = le16_to_cpu(hdr->type),
> 		.reply = true,
> +
> +		/* Set sk owner to socket we are replying to (may be NULL for
> +		 * non-loopback). This keeps a reference to the sock and
> +		 * sock_net(sk) until the reply skb is freed.
> +		 */
> +		.vsk = vsock_sk(skb->sk),
> 	};
> 	struct sk_buff *reply;
>
>
> --
> 2.47.3