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

Ben Hutchings
2018-12-09T22:27:09Z

From: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>

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@cmss.chinamobile.com>

Changes in v2:
- Unnecessary to initialize rc to zero.
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
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,