1 files changed, 17 insertions, 12 deletions

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 6833ef0c7930..b18acd810561 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -159,19 +159,17 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	int len;
 	unsigned char *data;
 	__u32 seq_recv;
-
-
 	struct rtable *rt;
 	struct net_device *tdev;
 	struct iphdr  *iph;
 	int    max_headroom;
 
 	if (sk_pppox(po)->sk_state & PPPOX_DEAD)
-		goto tx_error;
+		goto tx_drop;
 
 	rt = pptp_route_output(po, &fl4);
 	if (IS_ERR(rt))
-		goto tx_error;
+		goto tx_drop;
 
 	tdev = rt->dst.dev;
 
@@ -179,16 +177,20 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 
 	if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) {
 		struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
-		if (!new_skb) {
-			ip_rt_put(rt);
+
+		if (!new_skb)
 			goto tx_error;
-		}
+
 		if (skb->sk)
 			skb_set_owner_w(new_skb, skb->sk);
 		consume_skb(skb);
 		skb = new_skb;
 	}
 
+	/* Ensure we can safely access protocol field and LCP code */
+	if (!pskb_may_pull(skb, 3))
+		goto tx_error;
+
 	data = skb->data;
 	islcp = ((data[0] << 8) + data[1]) == PPP_LCP && 1 <= data[2] && data[2] <= 7;
 
@@ -262,6 +264,8 @@ static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb)
 	return 1;
 
 tx_error:
+	ip_rt_put(rt);
+tx_drop:
 	kfree_skb(skb);
 	return 1;
 }
@@ -378,8 +382,8 @@ drop:
 	return NET_RX_DROP;
 }
 
-static int pptp_bind(struct socket *sock, struct sockaddr *uservaddr,
-	int sockaddr_len)
+static int pptp_bind(struct socket *sock, struct sockaddr_unsized *uservaddr,
+		     int sockaddr_len)
 {
 	struct sock *sk = sock->sk;
 	struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
@@ -411,8 +415,8 @@ out:
 	return error;
 }
 
-static int pptp_connect(struct socket *sock, struct sockaddr *uservaddr,
-	int sockaddr_len, int flags)
+static int pptp_connect(struct socket *sock, struct sockaddr_unsized *uservaddr,
+			int sockaddr_len, int flags)
 {
 	struct sock *sk = sock->sk;
 	struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr;
@@ -465,6 +469,7 @@ static int pptp_connect(struct socket *sock, struct sockaddr *uservaddr,
 	po->chan.mtu -= PPTP_HEADER_OVERHEAD;
 
 	po->chan.hdrlen = 2 + sizeof(struct pptp_gre_header);
+	po->chan.direct_xmit = true;
 	error = ppp_register_channel(&po->chan);
 	if (error) {
 		pr_err("PPTP: failed to register PPP channel (%d)\n", error);
@@ -694,6 +699,6 @@ module_init(pptp_init_module);
 module_exit(pptp_exit_module);
 
 MODULE_DESCRIPTION("Point-to-Point Tunneling Protocol");
-MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)");
+MODULE_AUTHOR("D. Kozlov <xeb@mail.ru>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_PPTP);