[RFC PATCH v1 1/3] virtio/vsock: fix header length on skb merging

[Arseniy Krasnov]

This fixes header length calculation of skbuff during data appending to
it. When such skbuff is processed in dequeue callbacks, e.g. 'skb_pull()'
is called on it, 'skb->len' is dynamic value, so it is impossible to use
it in header, because value from header must be permanent for valid
credit calculation ('rx_bytes'/'fwd_cnt').

Fixes: 077706165717 ("virtio/vsock: don't use skbuff state to account credit")
Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
 net/vmw_vsock/virtio_transport_common.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 6d15cd4d090a..3c75986e16c2 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1091,7 +1091,7 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
 			memcpy(skb_put(last_skb, skb->len), skb->data, skb->len);
 			free_pkt = true;
 			last_hdr->flags |= hdr->flags;
-			last_hdr->len = cpu_to_le32(last_skb->len);
+			le32_add_cpu(&last_hdr->len, len);
 			goto out;
 		}
 	}
-- 
2.25.1