[4.2.y-ckt stable] Patch "packet: fix heap info leak in PACKET_DIAG_MCLIST sock_diag interface" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

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

    packet: fix heap info leak in PACKET_DIAG_MCLIST sock_diag interface

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt9.

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

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 2f73d75fb8db9fbcfa3a55b85bfbb01d70791cb4 Mon Sep 17 00:00:00 2001
From: Mathias Krause <minipli at googlemail.com>
Date: Sun, 10 Apr 2016 12:52:28 +0200
Subject: packet: fix heap info leak in PACKET_DIAG_MCLIST sock_diag interface

commit 309cf37fe2a781279b7675d4bb7173198e532867 upstream.

Because we miss to wipe the remainder of i->addr[] in packet_mc_add(),
pdiag_put_mclist() leaks uninitialized heap bytes via the
PACKET_DIAG_MCLIST netlink attribute.

Fix this by explicitly memset(0)ing the remaining bytes in i->addr[].

Fixes: eea68e2f1a00 ("packet: Report socket mclist info via diag module")
Signed-off-by: Mathias Krause <minipli at googlemail.com>
Cc: Eric W. Biederman <ebiederm at xmission.com>
Cc: Pavel Emelyanov <xemul at parallels.com>
Acked-by: Pavel Emelyanov <xemul at virtuozzo.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/packet/af_packet.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 05a425b..5484016 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3309,6 +3309,7 @@ static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq)
 	i->ifindex = mreq->mr_ifindex;
 	i->alen = mreq->mr_alen;
 	memcpy(i->addr, mreq->mr_address, i->alen);
+	memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen);
 	i->count = 1;
 	i->next = po->mclist;
 	po->mclist = i;
--
2.7.4