[PATCH v2 0/1] virtio-vsock: Fix unbound rx buffer

From: Gerard Garcia <redacted>

This patch applies over VSOCK RFC v6.

Reset connection and close rx socket when the sender is ignoring our
announced available buffer. This avoids a DoS.

v2:
 * Get vvs->rx_lock lock before checking if next packet is going to
    overflow the rx buffer.

Gerard Garcia (1):
  Fix unbound rx buffer

 net/vmw_vsock/virtio_transport_common.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

-- 
2.9.1

From: Gerard Garcia <redacted>

Reset connection and close rx socket when the sender is ignoring our announced available buffer.

Signed-off-by: Gerard Garcia <redacted>

---
v2:
 * Get vvs->rx_lock lock before checking if next packet is going to
    overflow the rx buffer.

 net/vmw_vsock/virtio_transport_common.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index a53b3a1..8d4abb6 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c

@@ -774,12 +774,22 @@ virtio_transport_recv_connected(struct sock *sk,
 		pkt->off = 0;
 
 		spin_lock_bh(&vvs->rx_lock);
-		virtio_transport_inc_rx_pkt(vvs, pkt);
-		list_add_tail(&pkt->list, &vvs->rx_queue);
-		spin_unlock_bh(&vvs->rx_lock);
+		if (vvs->rx_bytes + pkt->len <= vvs->buf_size) {
+			virtio_transport_inc_rx_pkt(vvs, pkt);
+			list_add_tail(&pkt->list, &vvs->rx_queue);
+			spin_unlock_bh(&vvs->rx_lock);
+
+			sk->sk_data_ready(sk);
+			return err;
+		} else {
+			/* Sender is ignoring our buf_alloc */
+			spin_unlock_bh(&vvs->rx_lock);
+
+			virtio_transport_reset(vsk, pkt);
+			virtio_transport_do_close(vsk, true);
+			break;
+		}
 
-		sk->sk_data_ready(sk);
-		return err;
 	case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
 		sk->sk_write_space(sk);
 		break;

-- 
2.9.1

On Thu, Aug 04, 2016 at 04:09:57PM +0200, ggarcia@abra.uab.cat wrote:

From: Gerard Garcia <redacted>

Reset connection and close rx socket when the sender is ignoring our announced available buffer.

Signed-off-by: Gerard Garcia <redacted>

---
v2:
 * Get vvs->rx_lock lock before checking if next packet is going to
    overflow the rx buffer.

 net/vmw_vsock/virtio_transport_common.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

All of these patches need to be resubmitted with a proper subsystem
prefix in the Subject line.

Thank you.