[PATCH 3.16 027/328] vxlan: fix a potential issue when create a new vxlan fdb entry.

[Ben Hutchings]

3.16.62-rc1 review patch.  If anyone has any objections, please let me know.

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

From: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>

commit 17b463654f41f0aa334efd5a6efeab8a6e9496f7 upstream.

vxlan_fdb_append may return error, so add the proper check,
otherwise it will cause memory leak.

Signed-off-by: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx>

Changes in v2:
  - Unnecessary to initialize rc to zero.
Acked-by: Jiri Benc <jbenc@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/vxlan.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -695,6 +695,7 @@ static int vxlan_fdb_create(struct vxlan
 	struct vxlan_rdst *rd = NULL;
 	struct vxlan_fdb *f;
 	int notify = 0;
+	int rc;
 
 	f = __vxlan_find_mac(vxlan, mac);
 	if (f) {
@@ -729,8 +730,7 @@ static int vxlan_fdb_create(struct vxlan
 		if ((flags & NLM_F_APPEND) &&
 		    (is_multicast_ether_addr(f->eth_addr) ||
 		     is_zero_ether_addr(f->eth_addr))) {
-			int rc = vxlan_fdb_append(f, ip, port, vni, ifindex,
-						  &rd);
+			rc = vxlan_fdb_append(f, ip, port, vni, ifindex, &rd);
 
 			if (rc < 0)
 				return rc;
@@ -760,7 +760,11 @@ static int vxlan_fdb_create(struct vxlan
 		INIT_LIST_HEAD(&f->remotes);
 		memcpy(f->eth_addr, mac, ETH_ALEN);
 
-		vxlan_fdb_append(f, ip, port, vni, ifindex, &rd);
+		rc = vxlan_fdb_append(f, ip, port, vni, ifindex, &rd);
+		if (rc < 0) {
+			kfree(f);
+			return rc;
+		}
 
 		++vxlan->addrcnt;
 		hlist_add_head_rcu(&f->hlist,