6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Michal Luczaj <mhal@xxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: Michal Luczaj <mhal@xxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Acked-by: John Fastabend <john.fastabend@xxxxxxxxx>
Link: https://lore.kernel.org/bpf/20241013-vsock-fixes-for-redir-v2-2-d6577bbfe742@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 16ff976a86e3e..0f67cb0c64702 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1672,6 +1672,7 @@ 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;
@@ -1681,10 +1682,16 @@ 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);
}
--
2.43.0
