CVE-2025-21978: Linux kernel · drm/hyperv: Fix address space leak when Hyper-V DRM device is removed
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 5 Nov 2026, 23:23 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- EPSS
- 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Exploitation evidence
Disclosed: evidence found.
CVE published 1 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
Description
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.
References
- git.kernel.org/stable/c/c40cd24bfb9bfbb315c118ca14ebe6cf52e2dd1e (opens in a new tab)
- git.kernel.org/stable/c/ad27b4a51495490b815580d9b935e8eee14d1a9c (opens in a new tab)
- git.kernel.org/stable/c/24f1bbfb2be77dad82489c1468bbb14312aab129 (opens in a new tab)
- git.kernel.org/stable/c/158242b56bf465a73e1edeac0fe828a8acad4499 (opens in a new tab)
- git.kernel.org/stable/c/aed709355fd05ef747e1af24a1d5d78cd7feb81e (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/05/msg00045.html (opens in a new tab)