[PATCH] vxlan: fix dst ref count leak in the vxlan_xmit_one() error path

[Wentao Liang]

In the vxlan_xmit_one(), when the encap_bypass_if_local() returns an
error, the function jumps to out_unlock without releasing the dst
reference obtained from the udp_tunnel_dst_lookup(). This causes a
reference count leak in both IPv4 and IPv6 paths.

Fix by calling the dst_release() before goto out_unlock in both error
paths:
- For IPv4: release &rt->dst
- For IPv6: release ndst

Fixes: 56de859e9967 ("vxlan: lock RCU on TX path")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
---
 drivers/net/vxlan/vxlan_core.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index dab864bc733c..41bbc92cc234 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -2479,8 +2479,10 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 			err = encap_bypass_if_local(skb, dev, vxlan, AF_INET,
 						    dst_port, ifindex, vni,
 						    &rt->dst, rt->rt_flags);
-			if (err)
+			if (err) {
+				dst_release(&rt->dst);
 				goto out_unlock;
+			}
 
 			if (vxlan->cfg.df == VXLAN_DF_SET) {
 				df = htons(IP_DF);
@@ -2560,8 +2562,10 @@ void vxlan_xmit_one(struct sk_buff *skb, struct net_device *dev,
 			err = encap_bypass_if_local(skb, dev, vxlan, AF_INET6,
 						    dst_port, ifindex, vni,
 						    ndst, rt6i_flags);
-			if (err)
+			if (err) {
+				dst_release(ndst);
 				goto out_unlock;
+			}
 		}
 
 		err = skb_tunnel_check_pmtu(skb, ndst,
-- 
2.34.1