6.1-stable review patch. If anyone has any objections, please let me know.
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From: Filippo Storniolo f.storniolo95@gmail.com
[ Upstream commit 3a5cc90a4d1756072619fe511d07621bdef7f120 ]
If the same remote peer, using the same port, tries to connect to a server on a listening port more than once, the server will reject the connection, causing a "connection reset by peer" error on the remote peer. This is due to the presence of a dangling socket from a previous connection in both the connected and bound socket lists. The inconsistency of the above lists only occurs when the remote peer disconnects and the server remains active.
This bug does not occur when the server socket is closed: virtio_transport_release() will eventually schedule a call to virtio_transport_do_close() and the latter will remove the socket from the bound and connected socket lists and clear the sk_buff.
However, virtio_transport_do_close() will only perform the above actions if it has been scheduled, and this will not happen if the server is processing the shutdown message from a remote peer.
To fix this, introduce a call to vsock_remove_sock() when the server is handling a client disconnect. This is to remove the socket from the bound and connected socket lists without clearing the sk_buff.
Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko") Reported-by: Daan De Meyer daan.j.demeyer@gmail.com Tested-by: Daan De Meyer daan.j.demeyer@gmail.com Co-developed-by: Luigi Leonardi luigi.leonardi@outlook.com Signed-off-by: Luigi Leonardi luigi.leonardi@outlook.com Signed-off-by: Filippo Storniolo f.storniolo95@gmail.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/vmw_vsock/virtio_transport_common.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index a1581c77cf84a..73e5093928325 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -1108,11 +1108,17 @@ virtio_transport_recv_connected(struct sock *sk, vsk->peer_shutdown |= RCV_SHUTDOWN; if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_SEND) vsk->peer_shutdown |= SEND_SHUTDOWN; - if (vsk->peer_shutdown == SHUTDOWN_MASK && - vsock_stream_has_data(vsk) <= 0 && - !sock_flag(sk, SOCK_DONE)) { - (void)virtio_transport_reset(vsk, NULL); - virtio_transport_do_close(vsk, true); + if (vsk->peer_shutdown == SHUTDOWN_MASK) { + if (vsock_stream_has_data(vsk) <= 0 && !sock_flag(sk, SOCK_DONE)) { + (void)virtio_transport_reset(vsk, NULL); + virtio_transport_do_close(vsk, true); + } + /* Remove this socket anyway because the remote peer sent + * the shutdown. This way a new connection will succeed + * if the remote peer uses the same source port, + * even if the old socket is still unreleased, but now disconnected. + */ + vsock_remove_sock(vsk); } if (le32_to_cpu(virtio_vsock_hdr(skb)->flags)) sk->sk_state_change(sk);