bridge: fix mdb info leaks

[ 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>

diff --git a/net/bridge/br_mdb.c b/net/bridge/br_mdb.c
index acc9f4cc18f77a3598b2190e2f38f3acb8a03e36..2897e40edde46e1fdef5e840f9e00a6bf460ef14 100644 (file)
--- a/net/bridge/br_mdb.c
+++ b/net/bridge/br_mdb.c
@@ -82,6 +82,7 @@ static int br_mdb_fill_info(struct sk_buff *skb, struct netlink_callback *cb,
                                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 *skb, struct netlink_callback *cb)
                                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(struct sk_buff *skb,
                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 *dev, struct net_bridge_port *port,
 {
        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;