diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a1b0697..4c5ae95 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -155,6 +155,7 @@ static int tun_attach(struct tun_struct *tun, struct file *file)
 	err = 0;
 	tfile->tun = tun;
 	tun->tfile = tfile;
+	tun->sk->sk_sleep = &tfile->read_wait;
 	dev_hold(tun->dev);
 	atomic_inc(&tfile->count);
 
@@ -173,6 +174,8 @@ static void __tun_detach(struct tun_struct *tun)
 	tun->tfile = NULL;
 	netif_tx_unlock_bh(tun->dev);
 
+	tun->sk->sk_sleep = NULL;
+
 	/* Drop read queue */
 	skb_queue_purge(&tun->readq);
 
@@ -861,7 +864,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 	struct sock *sk;
 	struct tun_struct *tun;
 	struct net_device *dev;
-	struct tun_file *tfile = file->private_data;
 	int err;
 
 	dev = __dev_get_by_name(net, ifr->ifr_name);
@@ -925,7 +927,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		sk->sk_write_space = tun_sock_write_space;
 		sk->sk_destruct = tun_sock_destruct;
 		sk->sk_sndbuf = INT_MAX;
-		sk->sk_sleep = &tfile->read_wait;
 
 		tun->sk = sk;
 		container_of(sk, struct tun_sock, sk)->tun = tun;