CVE-2025-71201

A race condition flaw was found in the Linux kernel's netfs subsystem. In the netfs_read_unlock_folios() function, a folio (memory page) may be unlocked prematurely before the ZERO subrequest completes clearing the tail portion of the page beyond the end-of-file. This allows an application using mmap to observe uninitialized kernel memory contents in the uncleared tail region, potentially leading to information disclosure.

This flaw primarily affects network filesystems using the netfs helper library, particularly 9P which uses synchronous reads. AFS and CIFS are less likely to exhibit this behavior due to their asynchronous read dispatch. The information disclosure is limited to uninitialized page contents and requires specific file sizes and mmap access patterns.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.