CVE-2025-21769 ptp: vmclock: Add .owner to vmclock_miscdev_fops

What is CVE-2025-21769?

CVE-2025-21769 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

ptp: vmclock: Add .owner to vmclock_miscdev_fops

Without the .owner field, the module can be unloaded while /dev/vmclock0 is open, leading to an oops.

Which versions are affected by CVE-2025-21769?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2025-21769?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2025-21769 being exploited?

There is no known exploitation of CVE-2025-21769 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BELL-CVE-2025-21769, GHSA-g2f3-xcg7-rxp6, UBUNTU-CVE-2025-21769.