CVE-2026-99241
Received Received - Intake

NTFS Invalidate Lock Race Condition in Linux Kernel

Publication date: 2026-11-02

Last updated on: 2026-11-02

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ntfs: take invalidate_lock in ntfs_filemap_page_mkwrite() ntfs_filemap_page_mkwrite() calls iomap_page_mkwrite() without holding mapping->invalidate_lock, so a concurrent truncate or fallocate can be in the middle of invalidating pagecache and rewriting the runlist while the write fault maps blocks and dirties the folio. This races with ntfs_attr_fallocate(), which merges clusters into the in-memory runlist, drops the runlist lock, and only afterwards zeroes the newly allocated clusters on disk; and with the punch-hole/insert/collapse paths that free clusters after truncating the cache. Per Documentation/filesystems/locking.rst, ->page_mkwrite() must ensure there are no truncate/invalidate races, "usually mapping->invalidate_lock is suitable for proper serialization". xfs takes its mmaplock (= the invalidate_lock rwsem) shared in exactly this path. Take invalidate_lock shared around iomap_page_mkwrite(). The read-only fault path is already covered because filemap_fault() itself grabs invalidate_lock shared on instantiation/read paths; only page_mkwrite was bypassing it in this driver.

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Meta Information

Published
2026-11-02
Last Modified
2026-11-02
Generated
2026-11-02
AI Q&A
2026-11-02
EPSS Evaluated
N/A
NVD
CVE-2026-99241

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
Linux Linux 9c87959601e80b39a45250e362e6ddfec17cb0fa
Linux Linux 9c87959601e80b39a45250e362e6ddfec17cb0fa
Linux Linux 7.1

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a race condition in the NTFS file system. The ntfs_filemap_page_mkwrite() function calls iomap_page_mkwrite() without holding the mapping->invalidate_lock, which is supposed to prevent truncate or fallocate operations from interfering with pagecache invalidation and runlist rewriting. This can lead to concurrent operations corrupting file data or metadata.

Detection Guidance

This vulnerability is specific to the Linux kernel's NTFS implementation and involves a race condition during page write operations. Detection requires checking kernel logs for filesystem errors or crashes related to NTFS operations. Monitor for filesystem corruption or unexpected behavior during file writes or truncates.

Impact Analysis

This vulnerability could allow an attacker to corrupt file data or metadata on an NTFS file system, potentially leading to data loss, system crashes, or unauthorized access. It specifically affects write operations that map blocks and dirty folios while a truncate or fallocate operation is in progress.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel filesystem issue involving a race condition in NTFS page write operations, which could lead to data corruption or inconsistencies. Compliance impacts would only occur if such corruption affected protected data, but the CVE itself does not specify such scenarios.

Mitigation Strategies

Apply the latest Linux kernel updates that include the fix for this NTFS vulnerability. If immediate patching is not possible, avoid using NTFS filesystems for critical operations until patched. Monitor kernel logs for signs of exploitation or filesystem corruption.

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