From b32a09ea7c38849ff925489a6bf5bd8914bc45df Mon Sep 17 00:00:00 2001 From: Marco Pinna Date: Fri, 29 Mar 2024 17:12:59 +0100 Subject: [PATCH] vsock/virtio: fix packet delivery to tap device Commit 82dfb540aeb2 ("VSOCK: Add virtio vsock vsockmon hooks") added virtio_transport_deliver_tap_pkt() for handing packets to the vsockmon device. However, in virtio_transport_send_pkt_work(), the function is called before actually sending the packet (i.e. before placing it in the virtqueue with virtqueue_add_sgs() and checking whether it returned successfully). Queuing the packet in the virtqueue can fail even multiple times. However, in virtio_transport_deliver_tap_pkt() we deliver the packet to the monitoring tap interface only the first time we call it. This certainly avoids seeing the same packet replicated multiple times in the monitoring interface, but it can show the packet sent with the wrong timestamp or even before we succeed to queue it in the virtqueue. Move virtio_transport_deliver_tap_pkt() after calling virtqueue_add_sgs() and making sure it returned successfully. Fixes: 82dfb540aeb2 ("VSOCK: Add virtio vsock vsockmon hooks") Cc: stable@vge.kernel.org Signed-off-by: Marco Pinna Reviewed-by: Stefano Garzarella Link: https://lore.kernel.org/r/20240329161259.411751-1-marco.pinn95@gmail.com Signed-off-by: Jakub Kicinski --- net/vmw_vsock/virtio_transport.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 1748268e0694..ee5d306a96d0 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -120,7 +120,6 @@ virtio_transport_send_pkt_work(struct work_struct *work) if (!skb) break; - virtio_transport_deliver_tap_pkt(skb); reply = virtio_vsock_skb_reply(skb); sgs = vsock->out_sgs; sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb), @@ -170,6 +169,8 @@ virtio_transport_send_pkt_work(struct work_struct *work) break; } + virtio_transport_deliver_tap_pkt(skb); + if (reply) { struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; int val;