summaryrefslogtreecommitdiffstats
path: root/net/vmw_vsock
diff options
context:
space:
mode:
authorStefano Garzarella <sgarzare@redhat.com>2019-11-14 10:57:48 +0100
committerDavid S. Miller <davem@davemloft.net>2019-11-14 18:12:18 -0800
commit6a2c0962105ae8ceba182c4f616e0e41d7755591 (patch)
treeeddaccb735a16b747cb7e422c93d2319233e91ba /net/vmw_vsock
parentb1bba80a4376aef34de2b57bfb8834bd095703ed (diff)
downloadlinux-6a2c0962105ae8ceba182c4f616e0e41d7755591.tar.bz2
vsock: prevent transport modules unloading
This patch adds 'module' member in the 'struct vsock_transport' in order to get/put the transport module. This prevents the module unloading while sockets are assigned to it. We increase the module refcnt when a socket is assigned to a transport, and we decrease the module refcnt when the socket is destructed. Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Jorgen Hansen <jhansen@vmware.com> 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/af_vsock.c20
-rw-r--r--net/vmw_vsock/hyperv_transport.c2
-rw-r--r--net/vmw_vsock/virtio_transport.c2
-rw-r--r--net/vmw_vsock/vmci_transport.c1
4 files changed, 21 insertions, 4 deletions
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 5357714b6104..5cb0ae42d916 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -380,6 +380,16 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
}
EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
+static void vsock_deassign_transport(struct vsock_sock *vsk)
+{
+ if (!vsk->transport)
+ return;
+
+ vsk->transport->destruct(vsk);
+ module_put(vsk->transport->module);
+ vsk->transport = NULL;
+}
+
/* Assign a transport to a socket and call the .init transport callback.
*
* Note: for stream socket this must be called when vsk->remote_addr is set
@@ -418,10 +428,13 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
return 0;
vsk->transport->release(vsk);
- vsk->transport->destruct(vsk);
+ vsock_deassign_transport(vsk);
}
- if (!new_transport)
+ /* We increase the module refcnt to prevent the transport unloading
+ * while there are open sockets assigned to it.
+ */
+ if (!new_transport || !try_module_get(new_transport->module))
return -ENODEV;
vsk->transport = new_transport;
@@ -741,8 +754,7 @@ static void vsock_sk_destruct(struct sock *sk)
{
struct vsock_sock *vsk = vsock_sk(sk);
- if (vsk->transport)
- vsk->transport->destruct(vsk);
+ vsock_deassign_transport(vsk);
/* When clearing these addresses, there's no need to set the family and
* possibly register the address family with the kernel.
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 1c9e65d7d94d..3c7d07a99fc5 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -857,6 +857,8 @@ int hvs_notify_send_post_enqueue(struct vsock_sock *vsk, ssize_t written,
}
static struct vsock_transport hvs_transport = {
+ .module = THIS_MODULE,
+
.get_local_cid = hvs_get_local_cid,
.init = hvs_sock_init,
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 83ad85050384..1458c5c8b64d 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -462,6 +462,8 @@ static void virtio_vsock_rx_done(struct virtqueue *vq)
static struct virtio_transport virtio_transport = {
.transport = {
+ .module = THIS_MODULE,
+
.get_local_cid = virtio_transport_get_local_cid,
.init = virtio_transport_do_socket_init,
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index d9c9c834ad6f..644d32e43d23 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -2020,6 +2020,7 @@ static u32 vmci_transport_get_local_cid(void)
}
static struct vsock_transport vmci_transport = {
+ .module = THIS_MODULE,
.init = vmci_transport_socket_init,
.destruct = vmci_transport_destruct,
.release = vmci_transport_release,