[PATCH 048/150] dcbnl: fix various netlink info leaks

[Luis Henriques]

3.5.7.9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mathias Krause <minipli@xxxxxxxxxxxxxx>

commit 29cd8ae0e1a39e239a3a7b67da1986add1199fc0 upstream.

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@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 net/dcb/dcbnl.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 656c7c7..9499791 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -337,6 +337,7 @@ static int dcbnl_getperm_hwaddr(struct net_device *netdev, struct nlattr **tb,
 	dcb->dcb_family = AF_UNSPEC;
 	dcb->cmd = DCB_CMD_GPERM_HWADDR;
 
+	memset(perm_addr, 0, sizeof(perm_addr));
 	netdev->dcbnl_ops->getpermhwaddr(netdev, perm_addr);
 
 	ret = nla_put(dcbnl_skb, DCB_ATTR_PERM_HWADDR, sizeof(perm_addr),
@@ -1243,6 +1244,7 @@ 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))
@@ -1251,6 +1253,7 @@ 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,
@@ -1262,6 +1265,7 @@ 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))
@@ -1295,6 +1299,7 @@ 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))
@@ -1303,6 +1308,7 @@ 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))
@@ -1487,6 +1493,7 @@ 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))
@@ -1495,6 +1502,7 @@ 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))
-- 
1.8.1.2

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