How to fix CVE-2025-21978?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Vendor patch is available.

Is Linux Kernel affected by CVE-2025-21978?

CVE-2025-21978 presents moderate security risk rated CVSS 5.5. Exploitation could compromise the security of affected deployments. A patch is available and should be applied during regular vulnerability management.

CVE-2025-21978

MEDIUM

2025-04-01 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Information Disclosure Linux Linux Kernel Redhat Suse

5.5

CVSS 3.1

CVSS VectorNVD

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 18:34 vuln.today

Patch Released

Mar 28, 2026 - 18:34 nvd

Patch available

CVE Published

Apr 01, 2025 - 16:15 nvd

MEDIUM 5.5

DescriptionNVD

In the Linux kernel, the following vulnerability has been resolved:

drm/hyperv: Fix address space leak when Hyper-V DRM device is removed

When a Hyper-V DRM device is probed, the driver allocates MMIO space for the vram, and maps it cacheable. If the device removed, or in the error path for device probing, the MMIO space is released but no unmap is done. Consequently the kernel address space for the mapping is leaked.

Fix this by adding iounmap() calls in the device removal path, and in the error path during device probing.

AnalysisAI

In the Linux kernel, the following vulnerability has been resolved: drm/hyperv: Fix address space leak when Hyper-V DRM device is removed When a Hyper-V DRM device is probed, the driver allocates. Rated medium severity (CVSS 5.5), this vulnerability is low attack complexity. This Memory Leak vulnerability could allow attackers to exhaust available memory leading to denial of service.

Technical ContextAI

This vulnerability is classified as Memory Leak (CWE-401), which allows attackers to exhaust available memory leading to denial of service. In the Linux kernel, the following vulnerability has been resolved: drm/hyperv: Fix address space leak when Hyper-V DRM device is removed When a Hyper-V DRM device is probed, the driver allocates MMIO space for the vram, and maps it cacheable. If the device removed, or in the error path for device probing, the MMIO space is released but no unmap is done. Consequently the kernel address space for the mapping is leaked. Fix this by adding iounmap() calls in the device removal path, and in the error path during device probing. Affected products include: Linux Linux Kernel.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Ensure all allocated memory is properly freed. Use RAII patterns or garbage-collected languages.

Vendor StatusVendor

CVE-2025-21978 vulnerability details – vuln.today

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CVE-2025-21978

CVSS VectorNVD

Lifecycle Timeline

DescriptionNVD

AnalysisAI

Technical ContextAI

RemediationAI

Vendor StatusVendor

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