Linux Kernel Page Cache Statistics Vulnerability in Cachestat System Call

CVE-2025-21691

Summary

A vulnerability in the Linux kernel's cachestat system call allows unauthorized access to page cache statistics. Initially designed for improved performance, the cachestat function failed to implement proper checks for writability and ownership, leaving it susceptible to exploitation. This oversight mirrors a previously resolved issue in the mincore system call and necessitates careful attention to ensure proper file context checks are enforced.

References