dcbnl: fix various netlink info leaks

The dcb netlink interface leaks stack memory in various places:
* perm_addr[] buffer is only filled at max with 12 of the 32 bytes but
  copied completely,
* no in-kernel driver fills all fields of an IEEE 802.1Qaz subcommand,
  so we're leaking up to 58 bytes for ieee_ets structs, up to 136 bytes
  for ieee_pfc structs, etc.,
* the same is true for CEE -- no in-kernel driver fills the whole
  struct,

Prevent all of the above stack info leaks by properly initializing the
buffers/structures involved.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 1b588e23cf80..21291f1abcd6 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -284,6 +284,7 @@ static int dcbnl_getperm_hwaddr(struct net_device *netdev, struct nlmsghdr *nlh,
         if (!netdev->dcbnl_ops->getpermhwaddr)
                 return -EOPNOTSUPP;
 
+        memset(perm_addr, 0, sizeof(perm_addr));
         netdev->dcbnl_ops->getpermhwaddr(netdev, perm_addr);
 
         return nla_put(skb, DCB_ATTR_PERM_HWADDR, sizeof(perm_addr), perm_addr);
@@ -1042,6 +1043,7 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
 
         if (ops->ieee_getets) {
                 struct ieee_ets ets;
+                memset(&ets, 0, sizeof(ets));
                 err = ops->ieee_getets(netdev, &ets);
                 if (!err &&
                     nla_put(skb, DCB_ATTR_IEEE_ETS, sizeof(ets), &ets))
@@ -1050,6 +1052,7 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
 
         if (ops->ieee_getmaxrate) {
                 struct ieee_maxrate maxrate;
+                memset(&maxrate, 0, sizeof(maxrate));
                 err = ops->ieee_getmaxrate(netdev, &maxrate);
                 if (!err) {
                         err = nla_put(skb, DCB_ATTR_IEEE_MAXRATE,
@@ -1061,6 +1064,7 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
 
         if (ops->ieee_getpfc) {
                 struct ieee_pfc pfc;
+                memset(&pfc, 0, sizeof(pfc));
                 err = ops->ieee_getpfc(netdev, &pfc);
                 if (!err &&
                     nla_put(skb, DCB_ATTR_IEEE_PFC, sizeof(pfc), &pfc))
@@ -1094,6 +1098,7 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
         /* get peer info if available */
         if (ops->ieee_peer_getets) {
                 struct ieee_ets ets;
+                memset(&ets, 0, sizeof(ets));
                 err = ops->ieee_peer_getets(netdev, &ets);
                 if (!err &&
                     nla_put(skb, DCB_ATTR_IEEE_PEER_ETS, sizeof(ets), &ets))
@@ -1102,6 +1107,7 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
 
         if (ops->ieee_peer_getpfc) {
                 struct ieee_pfc pfc;
+                memset(&pfc, 0, sizeof(pfc));
                 err = ops->ieee_peer_getpfc(netdev, &pfc);
                 if (!err &&
                     nla_put(skb, DCB_ATTR_IEEE_PEER_PFC, sizeof(pfc), &pfc))
@@ -1280,6 +1286,7 @@ static int dcbnl_cee_fill(struct sk_buff *skb, struct net_device *netdev)
         /* peer info if available */
         if (ops->cee_peer_getpg) {
                 struct cee_pg pg;
+                memset(&pg, 0, sizeof(pg));
                 err = ops->cee_peer_getpg(netdev, &pg);
                 if (!err &&
                     nla_put(skb, DCB_ATTR_CEE_PEER_PG, sizeof(pg), &pg))
@@ -1288,6 +1295,7 @@ static int dcbnl_cee_fill(struct sk_buff *skb, struct net_device *netdev)
 
         if (ops->cee_peer_getpfc) {
                 struct cee_pfc pfc;
+                memset(&pfc, 0, sizeof(pfc));
                 err = ops->cee_peer_getpfc(netdev, &pfc);
                 if (!err &&
                     nla_put(skb, DCB_ATTR_CEE_PEER_PFC, sizeof(pfc), &pfc))