1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 961fad1f7053..f3a454c3295a 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -358,6 +358,8 @@ static void tun_free_netdev(struct net_device *dev)
 {
         struct tun_struct *tun = netdev_priv(dev);
 
+        BUG_ON(!test_bit(SOCK_EXTERNALLY_ALLOCATED, &tun->socket.flags));
+
         sk_release_kernel(tun->socket.sk);
 }
 
@@ -1115,6 +1117,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
                 tun->flags = flags;
                 tun->txflt.count = 0;
                 tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
+                set_bit(SOCK_EXTERNALLY_ALLOCATED, &tun->socket.flags);
 
                 err = -ENOMEM;
                 sk = sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL, &tun_proto);