[RFC PATCH v2 3/4] virtio/vsock: free skb on data copy failure

From: Arseniy Krasnov
Date: Sun Mar 05 2023 - 15:11:44 EST


This fixes two things in case when 'memcpy_to_msg()' fails:
1) Update credit parameters of the socket, like this skbuff was
copied to user successfully. This is needed because when skbuff was
received it's length was used to update 'rx_bytes', thus when we drop
skbuff here, we must account rest of it's data in 'rx_bytes'.
2) Free skbuff which was removed from socket's queue.

Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff")
Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
net/vmw_vsock/virtio_transport_common.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 30b0539990ba..ffb1af4f2b52 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -379,8 +379,12 @@ virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
spin_unlock_bh(&vvs->rx_lock);

err = memcpy_to_msg(msg, skb->data, bytes);
- if (err)
+ if (err) {
+ skb_pull(skb, skb->len);
+ virtio_transport_dec_rx_pkt(vvs, skb);
+ consume_skb(skb);
goto out;
+ }

spin_lock_bh(&vvs->rx_lock);

--
2.25.1