1 files changed, 88 insertions, 23 deletions

diff --git a/drivers/net/pppol2tp.c b/drivers/net/pppol2tp.c
index 8db342f2fdc9..70cfdb46aa27 100644
--- a/drivers/net/pppol2tp.c
+++ b/drivers/net/pppol2tp.c
@@ -240,12 +240,15 @@ static inline struct pppol2tp_session *pppol2tp_sock_to_session(struct sock *sk)
 	if (sk == NULL)
 		return NULL;
 
+	sock_hold(sk);
 	session = (struct pppol2tp_session *)(sk->sk_user_data);
-	if (session == NULL)
-		return NULL;
+	if (session == NULL) {
+		sock_put(sk);
+		goto out;
+	}
 
 	BUG_ON(session->magic != L2TP_SESSION_MAGIC);
-
+out:
 	return session;
 }
 
@@ -256,12 +259,15 @@ static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk)
 	if (sk == NULL)
 		return NULL;
 
+	sock_hold(sk);
 	tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data);
-	if (tunnel == NULL)
-		return NULL;
+	if (tunnel == NULL) {
+		sock_put(sk);
+		goto out;
+	}
 
 	BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
-
+out:
 	return tunnel;
 }
 
@@ -716,12 +722,14 @@ discard:
 	session->stats.rx_errors++;
 	kfree_skb(skb);
 	sock_put(session->sock);
+	sock_put(sock);
 
 	return 0;
 
 error:
 	/* Put UDP header back */
 	__skb_push(skb, sizeof(struct udphdr));
+	sock_put(sock);
 
 no_tunnel:
 	return 1;
@@ -745,10 +753,13 @@ static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
 	       "%s: received %d bytes\n", tunnel->name, skb->len);
 
 	if (pppol2tp_recv_core(sk, skb))
-		goto pass_up;
+		goto pass_up_put;
 
+	sock_put(sk);
 	return 0;
 
+pass_up_put:
+	sock_put(sk);
 pass_up:
 	return 1;
 }
@@ -858,7 +869,7 @@ static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msgh
 
 	tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
 	if (tunnel == NULL)
-		goto error;
+		goto error_put_sess;
 
 	/* What header length is configured for this session? */
 	hdr_len = pppol2tp_l2tp_header_len(session);
@@ -870,7 +881,7 @@ static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msgh
 			   sizeof(ppph) + total_len,
 			   0, GFP_KERNEL);
 	if (!skb)
-		goto error;
+		goto error_put_sess_tun;
 
 	/* Reserve space for headers. */
 	skb_reserve(skb, NET_SKB_PAD);
@@ -900,7 +911,7 @@ static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msgh
 	error = memcpy_fromiovec(skb->data, m->msg_iov, total_len);
 	if (error < 0) {
 		kfree_skb(skb);
-		goto error;
+		goto error_put_sess_tun;
 	}
 	skb_put(skb, total_len);
 
@@ -947,10 +958,33 @@ static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msgh
 		session->stats.tx_errors++;
 	}
 
+	return error;
+
+error_put_sess_tun:
+	sock_put(session->tunnel_sock);
+error_put_sess:
+	sock_put(sk);
 error:
 	return error;
 }
 
+/* Automatically called when the skb is freed.
+ */
+static void pppol2tp_sock_wfree(struct sk_buff *skb)
+{
+	sock_put(skb->sk);
+}
+
+/* For data skbs that we transmit, we associate with the tunnel socket
+ * but don't do accounting.
+ */
+static inline void pppol2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
+{
+	sock_hold(sk);
+	skb->sk = sk;
+	skb->destructor = pppol2tp_sock_wfree;
+}
+
 /* Transmit function called by generic PPP driver.  Sends PPP frame
  * over PPPoL2TP socket.
  *
@@ -993,10 +1027,10 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 
 	sk_tun = session->tunnel_sock;
 	if (sk_tun == NULL)
-		goto abort;
+		goto abort_put_sess;
 	tunnel = pppol2tp_sock_to_tunnel(sk_tun);
 	if (tunnel == NULL)
-		goto abort;
+		goto abort_put_sess;
 
 	/* What header length is configured for this session? */
 	hdr_len = pppol2tp_l2tp_header_len(session);
@@ -1009,7 +1043,7 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 		sizeof(struct udphdr) + hdr_len + sizeof(ppph);
 	old_headroom = skb_headroom(skb);
 	if (skb_cow_head(skb, headroom))
-		goto abort;
+		goto abort_put_sess_tun;
 
 	new_headroom = skb_headroom(skb);
 	skb_orphan(skb);
@@ -1069,7 +1103,7 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	/* Get routing info from the tunnel socket */
 	dst_release(skb->dst);
 	skb->dst = dst_clone(__sk_dst_get(sk_tun));
-	skb->sk = sk_tun;
+	pppol2tp_skb_set_owner_w(skb, sk_tun);
 
 	/* Queue the packet to IP for output */
 	len = skb->len;
@@ -1086,8 +1120,14 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 		session->stats.tx_errors++;
 	}
 
+	sock_put(sk_tun);
+	sock_put(sk);
 	return 1;
 
+abort_put_sess_tun:
+	sock_put(sk_tun);
+abort_put_sess:
+	sock_put(sk);
 abort:
 	/* Free the original skb */
 	kfree_skb(skb);
@@ -1191,7 +1231,7 @@ static void pppol2tp_tunnel_destruct(struct sock *sk)
 {
 	struct pppol2tp_tunnel *tunnel;
 
-	tunnel = pppol2tp_sock_to_tunnel(sk);
+	tunnel = sk->sk_user_data;
 	if (tunnel == NULL)
 		goto end;
 
@@ -1230,10 +1270,12 @@ static void pppol2tp_session_destruct(struct sock *sk)
 	if (sk->sk_user_data != NULL) {
 		struct pppol2tp_tunnel *tunnel;
 
-		session = pppol2tp_sock_to_session(sk);
+		session = sk->sk_user_data;
 		if (session == NULL)
 			goto out;
 
+		BUG_ON(session->magic != L2TP_SESSION_MAGIC);
+
 		/* Don't use pppol2tp_sock_to_tunnel() here to
 		 * get the tunnel context because the tunnel
 		 * socket might have already been closed (its
@@ -1279,6 +1321,7 @@ out:
 static int pppol2tp_release(struct socket *sock)
 {
 	struct sock *sk = sock->sk;
+	struct pppol2tp_session *session;
 	int error;
 
 	if (!sk)
@@ -1296,9 +1339,18 @@ static int pppol2tp_release(struct socket *sock)
 	sock_orphan(sk);
 	sock->sk = NULL;
 
+	session = pppol2tp_sock_to_session(sk);
+
 	/* Purge any queued data */
 	skb_queue_purge(&sk->sk_receive_queue);
 	skb_queue_purge(&sk->sk_write_queue);
+	if (session != NULL) {
+		struct sk_buff *skb;
+		while ((skb = skb_dequeue(&session->reorder_q))) {
+			kfree_skb(skb);
+			sock_put(sk);
+		}
+	}
 
 	release_sock(sk);
 
@@ -1601,7 +1653,7 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
 
 	error = ppp_register_channel(&po->chan);
 	if (error)
-		goto end;
+		goto end_put_tun;
 
 	/* This is how we get the session context from the socket. */
 	sk->sk_user_data = session;
@@ -1621,6 +1673,8 @@ out_no_ppp:
 	PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO,
 	       "%s: created\n", session->name);
 
+end_put_tun:
+	sock_put(tunnel_sock);
 end:
 	release_sock(sk);
 
@@ -1668,6 +1722,7 @@ static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr,
 	*usockaddr_len = len;
 
 	error = 0;
+	sock_put(sock->sk);
 
 end:
 	return error;
@@ -1906,14 +1961,17 @@ static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd,
 		err = -EBADF;
 		tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
 		if (tunnel == NULL)
-			goto end;
+			goto end_put_sess;
 
 		err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
-		goto end;
+		sock_put(session->tunnel_sock);
+		goto end_put_sess;
 	}
 
 	err = pppol2tp_session_ioctl(session, cmd, arg);
 
+end_put_sess:
+	sock_put(sk);
 end:
 	return err;
 }
@@ -2059,14 +2117,17 @@ static int pppol2tp_setsockopt(struct socket *sock, int level, int optname,
 		err = -EBADF;
 		tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
 		if (tunnel == NULL)
-			goto end;
+			goto end_put_sess;
 
 		err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
+		sock_put(session->tunnel_sock);
 	} else
 		err = pppol2tp_session_setsockopt(sk, session, optname, val);
 
 	err = 0;
 
+end_put_sess:
+	sock_put(sk);
 end:
 	return err;
 }
@@ -2181,20 +2242,24 @@ static int pppol2tp_getsockopt(struct socket *sock, int level,
 		err = -EBADF;
 		tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock);
 		if (tunnel == NULL)
-			goto end;
+			goto end_put_sess;
 
 		err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
+		sock_put(session->tunnel_sock);
 	} else
 		err = pppol2tp_session_getsockopt(sk, session, optname, &val);
 
 	err = -EFAULT;
 	if (put_user(len, (int __user *) optlen))
-		goto end;
+		goto end_put_sess;
 
 	if (copy_to_user((void __user *) optval, &val, len))
-		goto end;
+		goto end_put_sess;
 
 	err = 0;
+
+end_put_sess:
+	sock_put(sk);
 end:
 	return err;
 }