KVM: nVMX: Hide shadow VMCS right after VMCLEAR
In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Hide shadow VMCS right after VMCLEAR free_nested() frees the shadow VMCS while vmcs01 still points to it. But because it is asynchronous with respect to loaded_vmcs_clear(), the vCPU might migrate before the pointer is cleared and __loaded_vmcs_clear() may then execute VMCLEAR. The VMCS needs to stay attached until its explicit VMCLEAR completes, but then it can be hidden and the page safely freed.
02 / AFFECTED SOFTWARE
Affected packages
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Hide shadow VMCS right after VMCLEAR free_nested() frees the shadow VMCS while vmcs01 still points to it. But because it is asynchronous with respect to loaded_vmcs_clear(), the vCPU might migrate before the pointer is cleared and __loaded_vmcs_clear() may then execute VMCLEAR. The VMCS needs to stay attached until its explicit VMCLEAR completes, but then it can be hidden and the page safely freed.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/1dabef6e206568bf9d9ade74f6e56a48ea35695d
- https://git.kernel.org/stable/c/4f50e6aec16f69627dbad5704d1e90a255d766a7
- https://git.kernel.org/stable/c/589419470030a89f16cf19300658b6dc644ca946
- https://git.kernel.org/stable/c/622ebfac01ba4f9c0060cebd41257fe46fc4a0b3
- https://git.kernel.org/stable/c/8001d2ce9d9bd09118ce523aef595aa094573ae3
- https://git.kernel.org/stable/c/af56298e9d86e6098cd1d2e155cb2949b7c45412
- https://git.kernel.org/stable/c/b82c3144d8264265448292ca406f60bafeba3b6f
- https://git.kernel.org/stable/c/dc3eecfa219ebc9d01eaf7d1abd1441efe884dab
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64562.json
- https://nvd.nist.gov/vuln/detail/CVE-2026-64562