[ 3.5.y.z extended stable ] Patch "iucv: Fix missing msg_namelen update in iucv_sock_recvmsg()" has been added to staging queue

[Luis Henriques]

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

    iucv: Fix missing msg_namelen update in iucv_sock_recvmsg()

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

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

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 88c038e619d8d78c2d3669829498f897c96cfeff Mon Sep 17 00:00:00 2001
From: Mathias Krause <minipli at googlemail.com>
Date: Sun, 7 Apr 2013 01:51:54 +0000
Subject: [PATCH] iucv: Fix missing msg_namelen update in iucv_sock_recvmsg()

commit a5598bd9c087dc0efc250a5221e5d0e6f584ee88 upstream.

The current code does not fill the msg_name member in case it is set.
It also does not set the msg_namelen member to 0 and therefore makes
net/socket.c leak the local, uninitialized sockaddr_storage variable
to userland -- 128 bytes of kernel stack memory.

Fix that by simply setting msg_namelen to 0 as obviously nobody cared
about iucv_sock_recvmsg() not filling the msg_name in case it was set.

Cc: Ursula Braun <ursula.braun at de.ibm.com>
Signed-off-by: Mathias Krause <minipli at googlemail.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/iucv/af_iucv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index cd6f7a9..625bc50 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -1331,6 +1331,8 @@ static int iucv_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 	struct sk_buff *skb, *rskb, *cskb;
 	int err = 0;

+	msg->msg_namelen = 0;
+
 	if ((sk->sk_state == IUCV_DISCONN) &&
 	    skb_queue_empty(&iucv->backlog_skb_q) &&
 	    skb_queue_empty(&sk->sk_receive_queue) &&
--
1.8.1.2