UBUNTU-CVE-2026-74406

In the Linux kernel, the following vulnerability has been resolved: vxlan: Fix potential null-ptr-deref in vxlangropreparereceive. udptunnelsockrelease could set sk-skuserdata to NULL while vxlangropreparereceive is running. Let's check if rcudereferenceskuserdata is NULL after skbgroremcsuminit...