[3.13.y-ckt stable] Patch "pptp: fix stack info leak in pptp_getname()" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    pptp: fix stack info leak in pptp_getname()

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt13.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 94abf4c7c3955fdd5b365b4b568af14aab6ef651 Mon Sep 17 00:00:00 2001
From: Mathias Krause <minipli at googlemail.com>
Date: Wed, 19 Nov 2014 18:05:26 +0100
Subject: pptp: fix stack info leak in pptp_getname()

[ Upstream commit a5f6fc28d6e6cc379c6839f21820e62262419584 ]

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 at mail.ru>
Signed-off-by: Mathias Krause <minipli at googlemail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 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 1aff970..1dc628f 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;

--
1.9.1