[PATCH 6.1 040/312] openvswitch: defer tunnel netdev_put to RCU release

Greg Kroah-Hartman
2026-04-08T18:08:36Z

From: Yang Yang <n05ec@lzu.edu.cn>

[ Upstream commit 6931d21f87bc6d657f145798fad0bf077b82486c ]

ovs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already
detached the device. Dropping the netdev reference in destroy can race
with concurrent readers that still observe vport->dev.

Do not release vport->dev in ovs_netdev_tunnel_destroy(). Instead, let
vport_netdev_free() drop the reference from the RCU callback, matching
the non-tunnel destroy path and avoiding additional synchronization
under RTNL.

Fixes: a9020fde67a6 ("openvswitch: Move tunnel destroy function to oppenvswitch module.")
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Tested-by: Ao Zhou <n05ec@lzu.edu.cn>
Co-developed-by: Yuan Tan <tanyuan98@outlook.com>
Signed-off-by: Yuan Tan <tanyuan98@outlook.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Yang Yang <n05ec@lzu.edu.cn>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Link: https://patch.msgid.link/20260319074241.3405262-1-n05ec@lzu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/openvswitch/vport-netdev.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/net/openvswitch/vport-netdev.c b/net/openvswitch/vport-netdev.c
index 18376e10aeedc..68d38c12427c1 100644
--- a/net/openvswitch/vport-netdev.c
+++ b/net/openvswitch/vport-netdev.c
@@ -189,8 +189,6 @@ void ovs_netdev_tunnel_destroy(struct vport *vport)
*/
if (vport->dev->reg_state == NETREG_REGISTERED)
rtnl_delete_link(vport->dev, 0, NULL);
- netdev_put(vport->dev, &vport->dev_tracker);
- vport->dev = NULL;
rtnl_unlock();

call_rcu(&vport->rcu, vport_netdev_free);
--
2.51.0