openvswitch: defer tunnel netdev_put to RCU release
In the Linux kernel, the following vulnerability has been resolved: openvswitch: defer tunnel netdev_put to RCU release 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.
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: openvswitch: defer tunnel netdev_put to RCU release 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.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/42f0d3d81209654c08ffdde5a34b9b92d2645896
- https://git.kernel.org/stable/c/6931d21f87bc6d657f145798fad0bf077b82486c
- https://git.kernel.org/stable/c/98b726ab5e2a4811e27c28e4d041f75bba147eab
- https://git.kernel.org/stable/c/9d56aced21fb9c104e8a3f3be9b21fbafe448ffc
- https://git.kernel.org/stable/c/b8c56a3fc5d879c0928f207a756b0f067f06c6a8
- https://git.kernel.org/stable/c/bbe7bd722bfaea36aab3da6cc60fb4a05c644643
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31678.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-31678