CVE-2025-40102
Description
A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) for ARM64 architectures. A local user can exploit this vulnerability by sending virtual CPU (vCPU) events to a vCPU that has not been properly initialized. This improper handling of uninitialized vCPU events can lead to the kernel interpreting garbage data, causing the vCPU to enter an illegal state and triggering a kernel bug, ultimately resulting in a denial of service.
Mitigation
If virtualization is not required on ARM64 systems, the `kvm_arm64` kernel module can be prevented from loading to mitigate this vulnerability. This can be achieved by creating a modprobe configuration file:
bash
echo "install kvm_arm64 /bin/true" > /etc/modprobe.d/disable-kvm_arm64.conf
After creating the file, a system reboot is required for the changes to take effect. This mitigation will prevent the system from hosting ARM64 virtual machines.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory; Read Application Data
When reusing a resource such as memory or a program variable, the original contents of that resource may not be cleared before it is sent to an untrusted party.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
The uninitialized resource may contain values that cause program flow to change in ways that the programmer did not intend.
Frequently Asked Questions
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