CLSA-2025-1749548422 Fix of 14 CVEs

CVE-url: https://ubuntu.com/security/CVE-2025-21811 - nilfs2: protect access to buffers with no active references CVE-url: https://ubuntu.com/security/CVE-2025-21715 - net: davicom: fix UAF in dm9000drvremove CVE-url: https://ubuntu.com/security/CVE-2024-58083 - KVM: Explicitly verify target vCPU...