diff options
| author | Stefano Garzarella <sgarzare@redhat.com> | 2019-10-17 14:44:03 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-10-18 19:19:43 +0200 |
| commit | ae6fcfbf5f03de3407b809aaee319330d3dc7f8b (patch) | |
| tree | 5fbcf9656666a376a80edc90c21a1de0da79e343 /net/vmw_vsock | |
| parent | vsock/virtio: send a credit update when buffer size is changed (diff) | |
| download | linux-ae6fcfbf5f03de3407b809aaee319330d3dc7f8b.tar.xz linux-ae6fcfbf5f03de3407b809aaee319330d3dc7f8b.zip | |
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.c | 14 |
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 |