Linux Kernel Vulnerability in PTP Callback Handling

CVE-2025-21814

Summary

A vulnerability exists in the Linux kernel related to the Precision Time Protocol (PTP) drivers, where the ioctl and sysfs handlers unconditionally invoke the ->enable callback. This can lead to NULL dereferences in scenarios where some drivers, such as ptp_s390.c, ptp_vclock.c, and ptp_mock.c, do not implement this callback properly. The solution involves implementing a dummy callback in the absence of a specified driver callback, ensuring more robust handling of driver operations.

References