CVE-2025-21822: Linux kernel · ptp: vmclock: Set driver data before its usage
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 29 Oct 2026, 22:54 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Feb 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 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.2pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.5pkg:deb/ubuntu/linux-aws-6.5?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-azure-5.19pkg:deb/ubuntu/linux-azure-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available that sets the driver data before its usage during the probe process. Users should update to patched kernel versions to remediate this issue. No additional mitigation is required beyond applying the official fix.
Description
A vulnerability in the Linux kernel's ptp vmclock driver was identified where driver data was accessed before being set during error handling in vmclock_ptp_register(). This could lead to improper cleanup and potential system instability. The issue affects multiple specific kernel versions used in various Ubuntu LTS releases. The vulnerability has a medium severity score and does not impact confidentiality or integrity but can affect availability.
References
- ubuntu.com/security/CVE-2025-21822 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21822 (opens in a new tab)
- git.kernel.org/linus/f7d07cd4f77d77f366c8ffbb8ba8b61f614e5fce (opens in a new tab)
- git.kernel.org/stable/c/6dbd8b91a065d1d8001446a28e72cd140f9acef0 (opens in a new tab)
- git.kernel.org/stable/c/f7d07cd4f77d77f366c8ffbb8ba8b61f614e5fce (opens in a new tab)