[PATCH 3.16.y-ckt 097/126] pptp: verify sockaddr_len in pptp_bind() and pptp_connect()

[Luis Henriques]

3.16.7-ckt22 -stable review patch.  If anyone has any objections, please let me know.

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

From: WANG Cong <xiyou.wangcong at gmail.com>

commit 09ccfd238e5a0e670d8178cf50180ea81ae09ae1 upstream.

Reported-by: Dmitry Vyukov <dvyukov at gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong at gmail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/net/ppp/pptp.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 1dc628ffce2b..0710214df2bf 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -420,6 +420,9 @@ static int pptp_bind(struct socket *sock, struct sockaddr *uservaddr,
 	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 *sock, struct sockaddr *uservaddr,
 	struct flowi4 fl4;
 	int error = 0;
 
+	if (sockaddr_len < sizeof(struct sockaddr_pppox))
+		return -EINVAL;
+
 	if (sp->sa_protocol != PX_PROTO_PPTP)
 		return -EINVAL;