[PATCH 4.1 27/43] pptp: verify sockaddr_len in pptp_bind() and pptp_connect()

[Greg Kroah-Hartman]

4.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: WANG Cong <xiyou.wangcong@xxxxxxxxx>

[ Upstream commit 09ccfd238e5a0e670d8178cf50180ea81ae09ae1 ]

Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ppp/pptp.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -420,6 +420,9 @@ static int pptp_bind(struct socket *sock
 	struct pptp_opt *opt = &po->proto.pptp;
 	int error = 0;
 
+	if (sockaddr_len < sizeof(struct sockaddr_pppox))
+		return -EINVAL;
+
 	lock_sock(sk);
 
 	opt->src_addr = sp->sa_addr.pptp;
@@ -441,6 +444,9 @@ static int pptp_connect(struct socket *s
 	struct flowi4 fl4;
 	int error = 0;
 
+	if (sockaddr_len < sizeof(struct sockaddr_pppox))
+		return -EINVAL;
+
 	if (sp->sa_protocol != PX_PROTO_PPTP)
 		return -EINVAL;