[PATCH 4.3 39/55] pptp: verify sockaddr_len in pptp_bind() and pptp_connect()

[Greg Kroah-Hartman]

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

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

From: WANG Cong <xiyou.wangc...@gmail.com>

[ Upstream commit 09ccfd238e5a0e670d8178cf50180ea81ae09ae1 ]

Reported-by: Dmitry Vyukov <dvyu...@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/ppp/pptp.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -418,6 +418,9 @@ 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;
@@ -439,6 +442,9 @@ 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;