CVE-2025-21978: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

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

• Linux Linux Kernel: from 6.0, before 6.1.132 (fixed in 6.1.132); from 6.2, before 6.6.84 (fixed in 6.6.84); from 6.7, before 6.12.20 (fixed in 6.12.20); from 6.13, before 6.13.8 (fixed in 6.13.8); version 6.14 only

Published 2025-04-01. Last modified 2026-06-17.