Message-ID: <ef98aad4-f86d-fe60-9a35-792363a78a68@sberdevices.ru>
Date:   Sun, 5 Mar 2023 23:08:38 +0300
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To:     Stefan Hajnoczi <stefanha@redhat.com>,
        Stefano Garzarella <sgarzare@redhat.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Bobby Eshleman <bobby.eshleman@bytedance.com>
CC:     <kvm@vger.kernel.org>, <virtualization@lists.linux-foundation.org>,
        <netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <kernel@sberdevices.ru>, <oxffffaa@gmail.com>,
        <avkrasnov@sberdevices.ru>
From:   Arseniy Krasnov <avkrasnov@sberdevices.ru>
Subject: [RFC PATCH v2 3/4] virtio/vsock: free skb on data copy failure
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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@sberdevices.ru>
---
 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