6.6-stable review patch. If anyone has any objections, please let me know.
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From: Michal Luczaj mhal@rbox.co
[ Upstream commit 3543152f2d330141d9394d28855cb90b860091d2 ]
Make sure virtio_transport_inc_rx_pkt() and virtio_transport_dec_rx_pkt() calls are balanced (i.e. virtio_vsock_sock::rx_bytes doesn't lie) after vsock_transport::read_skb().
While here, also inform the peer that we've freed up space and it has more credit.
Failing to update rx_bytes after packet is dequeued leads to a warning on SOCK_STREAM recv():
[ 233.396654] rx_queue is empty, but rx_bytes is non-zero [ 233.396702] WARNING: CPU: 11 PID: 40601 at net/vmw_vsock/virtio_transport_common.c:589
Fixes: 634f1a7110b4 ("vsock: support sockmap") Suggested-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: Michal Luczaj mhal@rbox.co Signed-off-by: Daniel Borkmann daniel@iogearbox.net Reviewed-by: Stefano Garzarella sgarzare@redhat.com Acked-by: John Fastabend john.fastabend@gmail.com Link: https://lore.kernel.org/bpf/20241013-vsock-fixes-for-redir-v2-2-d6577bbfe742... Signed-off-by: Sasha Levin sashal@kernel.org --- net/vmw_vsock/virtio_transport_common.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index e87fd9480acda..072878012b51e 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -1508,6 +1508,7 @@ int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_acto { struct virtio_vsock_sock *vvs = vsk->trans; struct sock *sk = sk_vsock(vsk); + struct virtio_vsock_hdr *hdr; struct sk_buff *skb; int off = 0; int err; @@ -1517,10 +1518,16 @@ int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_acto * works for types other than dgrams. */ skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err); + if (!skb) { + spin_unlock_bh(&vvs->rx_lock); + return err; + } + + hdr = virtio_vsock_hdr(skb); + virtio_transport_dec_rx_pkt(vvs, le32_to_cpu(hdr->len)); spin_unlock_bh(&vvs->rx_lock);
- if (!skb) - return err; + virtio_transport_send_credit_update(vsk);
return recv_actor(sk, skb); }