CVE-2025-21814
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk12th percentile - higher than 12% of all known CVEs
Summary
In the Linux kernel, a vulnerability was found where the ->enable callback is called unconditionally without checking if it is implemented. Some drivers (e.g., ptp_s390, ptp_vclock, ptp_mock) do not define this callback, leading to NULL pointer dereference.
Risk Assessment
An attacker can cause a system crash (kernel panic) by sending a crafted ioctl request or interacting with sysfs, resulting in denial of service (DoS).
Recommendation
Immediately update the Linux kernel to a version containing the fix that replaces the missing callback with a dummy function.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: ptp: Ensure info->enable callback is always set The ioctl and sysfs handlers unconditionally call the ->enable callback. Not all drivers implement that callback, leading to NULL dereferences. Example of affected drivers: ptp_s390.c, ptp_vclock.c and ptp_mock.c. Instead use a dummy callback if no better was specified by the driver.