[ 70/75] bridge: fix mdb info leaks

Greg Kroah-Hartman
2013-03-18T21:47:38Z

From: Mathias Krause <minipli@googlemail.com>

[ Upstream commit c085c49920b2f900ba716b4ca1c1a55ece9872cc ]

The bridging code discloses heap and stack bytes via the RTM_GETMDB
netlink interface and via the notify messages send to group RTNLGRP_MDB
afer a successful add/del.

Fix both cases by initializing all unset members/padding bytes with
memset(0).

Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bridge/br_mdb.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -82,6 +82,7 @@ static int br_mdb_fill_info(struct sk_bu
port = p->port;
if (port) {
struct br_mdb_entry e;
+ memset(&e, 0, sizeof(e));
e.ifindex = port->dev->ifindex;
e.state = p->state;
if (p->addr.proto == htons(ETH_P_IP))
@@ -138,6 +139,7 @@ static int br_mdb_dump(struct sk_buff *s
break;

bpm = nlmsg_data(nlh);
+ memset(bpm, 0, sizeof(*bpm));
bpm->ifindex = dev->ifindex;
if (br_mdb_fill_info(skb, cb, dev) < 0)
goto out;
@@ -173,6 +175,7 @@ static int nlmsg_populate_mdb_fill(struc
return -EMSGSIZE;

bpm = nlmsg_data(nlh);
+ memset(bpm, 0, sizeof(*bpm));
bpm->family = AF_BRIDGE;
bpm->ifindex = dev->ifindex;
nest = nla_nest_start(skb, MDBA_MDB);
@@ -230,6 +233,7 @@ void br_mdb_notify(struct net_device *de
{
struct br_mdb_entry entry;

+ memset(&entry, 0, sizeof(entry));
entry.ifindex = port->dev->ifindex;
entry.addr.proto = group->proto;
entry.addr.u.ip4 = group->u.ip4;