[PATCH 3.16.y-ckt 008/168] pptp: fix stack info leak in pptp_getname()

From: Luis Henriques
Date: Mon Dec 15 2014 - 10:20:32 EST

3.16.7-ckt3 -stable review patch. If anyone has any objections, please let me know.


From: Mathias Krause <minipli@xxxxxxxxxxxxxx>

commit a5f6fc28d6e6cc379c6839f21820e62262419584 upstream.

pptp_getname() only partially initializes the stack variable sa,
particularly only fills the pptp part of the sa_addr union. The code
thereby discloses 16 bytes of kernel stack memory via getsockname().

Fix this by memset(0)'ing the union before.

Cc: Dmitry Kozlov <xeb@xxxxxxx>
Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
drivers/net/ppp/pptp.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c
index 1aff970be33e..1dc628ffce2b 100644
--- a/drivers/net/ppp/pptp.c
+++ b/drivers/net/ppp/pptp.c
@@ -506,7 +506,9 @@ static int pptp_getname(struct socket *sock, struct sockaddr *uaddr,
int len = sizeof(struct sockaddr_pppox);
struct sockaddr_pppox sp;

- sp.sa_family = AF_PPPOX;
+ memset(&sp.sa_addr, 0, sizeof(sp.sa_addr));
+ sp.sa_family = AF_PPPOX;
sp.sa_protocol = PX_PROTO_PPTP;
sp.sa_addr.pptp = pppox_sk(sock->sk)->proto.pptp.src_addr;


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/