linux-kernel - [PATCH] vxlan: fix dst ref count leak in the vxlan_xmit

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20251216033647.1792250-1-vulab@iscas.ac.cn>
Date: Tue, 16 Dec 2025 03:36:47 +0000
From: Wentao Liang <vulab@...as.ac.cn>
To: andrew+netdev@...n.ch,
	davem@...emloft.net,
	edumazet@...gle.com,
	kuba@...nel.org,
	pabeni@...hat.com
Cc: razor@...ckwall.org,
	petrm@...dia.com,
	netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Wentao Liang <vulab@...as.ac.cn>,
	stable@...r.kernel.org
Subject: [PATCH] vxlan: fix dst ref count leak in the vxlan_xmit_one() error path

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@...r.kernel.org
Signed-off-by: Wentao Liang <vulab@...as.ac.cn>
---
 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