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authorStefano Garzarella <sgarzare@redhat.com>2019-10-17 14:44:03 +0200
committerDavid S. Miller <davem@davemloft.net>2019-10-18 10:19:43 -0700
commitae6fcfbf5f03de3407b809aaee319330d3dc7f8b (patch)
tree5fbcf9656666a376a80edc90c21a1de0da79e343 /net/vmw_vsock
parentec3359b685db834c249953db6ac5717bf5cde425 (diff)
vsock/virtio: discard packets if credit is not respected
If the remote peer doesn't respect the credit information (buf_alloc, fwd_cnt), sending more data than it can send, we should drop the packets to prevent a malicious peer from using all of our memory. This is patch follows the VIRTIO spec: "VIRTIO_VSOCK_OP_RW data packets MUST only be transmitted when the peer has sufficient free buffer space for the payload" Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/vmw_vsock')
-rw-r--r--net/vmw_vsock/virtio_transport_common.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index db127a69f5c3..481f7f8a1655 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -204,10 +204,14 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
return virtio_transport_get_ops()->send_pkt(pkt);
}
-static void virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
+static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
struct virtio_vsock_pkt *pkt)
{
+ if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
+ return false;
+
vvs->rx_bytes += pkt->len;
+ return true;
}
static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
@@ -879,14 +883,18 @@ virtio_transport_recv_enqueue(struct vsock_sock *vsk,
struct virtio_vsock_pkt *pkt)
{
struct virtio_vsock_sock *vvs = vsk->trans;
- bool free_pkt = false;
+ bool can_enqueue, free_pkt = false;
pkt->len = le32_to_cpu(pkt->hdr.len);
pkt->off = 0;
spin_lock_bh(&vvs->rx_lock);
- virtio_transport_inc_rx_pkt(vvs, pkt);
+ can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
+ if (!can_enqueue) {
+ free_pkt = true;
+ goto out;
+ }
/* Try to copy small packets into the buffer of last packet queued,
* to avoid wasting memory queueing the entire buffer with a small