3 files changed, 7 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);
diff --git a/include/linux/net.h b/include/linux/net.h
index e9ac2df079ba..dc95700de5df 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -72,6 +72,7 @@ struct net;
 #define SOCK_NOSPACE            2
 #define SOCK_PASSCRED           3
 #define SOCK_PASSSEC            4
+#define SOCK_EXTERNALLY_ALLOCATED 5
 
 #ifndef ARCH_HAS_SOCKET_TYPES
 /**
diff --git a/net/socket.c b/net/socket.c
index 6e0ccc09b313..0452dca4cd24 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -522,6 +522,9 @@ void sock_release(struct socket *sock)
         if (rcu_dereference_protected(sock->wq, 1)->fasync_list)
                 printk(KERN_ERR "sock_release: fasync list not empty!\n");
 
+        if (test_bit(SOCK_EXTERNALLY_ALLOCATED, &sock->flags))
+                return;
+
         this_cpu_sub(sockets_in_use, 1);
         if (!sock->file) {
                 iput(SOCK_INODE(sock));