---
id: CVE-2026-43127
title: 'ntfs3: fix circular locking dependency in run_unpack_ex'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ntfs3: fix circular locking dependency in run_unpack_ex

  Syzbot reported a circular locking dependency between wnd->rw_lock
  (sbi->used.bitmap) and ni->file.run_lock.

  T…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 57f7979aefdcef66326bda47e07ee0d8be64bf21 <
    d60f09d2d16c44a797d8cb67015cde2508720506
  - >-
    Linux >= db7fc56646cafe39599a4c21f1398e2bdfd5c185 <
    76016d15bbd90caa0ce7765fddf9bde8e943e601
  - >-
    Linux >= 5fc982fe7eca9d0cf7b25832450ebd4f7c8e1c36 <
    b014372b62237521444ee51384549bdf48b79015
  - >-
    Linux >= 5fc982fe7eca9d0cf7b25832450ebd4f7c8e1c36 <
    b8d22d9d8260b0f4f4d8e2898c98037c9982ea66
  - >-
    Linux >= 5fc982fe7eca9d0cf7b25832450ebd4f7c8e1c36 <
    08ce2fee1b869ecbfbd94e0eb2630e52203a2e03
  - Linux >= 6.6.66 < 6.6.160
  - Linux >= 6.12.5 < 6.12.114
  - Linux 6.13
published: '2026-05-06'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:40:09.954Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43127'
references:
  - url: 'https://git.kernel.org/stable/c/d60f09d2d16c44a797d8cb67015cde2508720506'
  - url: 'https://git.kernel.org/stable/c/76016d15bbd90caa0ce7765fddf9bde8e943e601'
  - url: 'https://git.kernel.org/stable/c/b014372b62237521444ee51384549bdf48b79015'
  - url: 'https://git.kernel.org/stable/c/b8d22d9d8260b0f4f4d8e2898c98037c9982ea66'
  - url: 'https://git.kernel.org/stable/c/08ce2fee1b869ecbfbd94e0eb2630e52203a2e03'
tags:
  - cve.org
epss: 0.00124
epssPercentile: 0.0191
ingestedAt: '2026-10-21T12:48:53.646Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

ntfs3: fix circular locking dependency in run_unpack_ex

Syzbot reported a circular locking dependency between wnd->rw_lock
(sbi->used.bitmap) and ni->file.run_lock.

The deadlock scenario:
1. ntfs_extend_mft() takes ni->file.run_lock then wnd->rw_lock.
2. run_unpack_ex() takes wnd->rw_lock then tries to acquire
   ni->file.run_lock inside ntfs_refresh_zone().

This creates an AB-BA deadlock.

Fix this by using down_read_trylock() instead of down_read() when
acquiring run_lock in run_unpack_ex(). If the lock is contended,
skip ntfs_refresh_zone() - the MFT zone will be refreshed on the
next MFT operation. This breaks the circular dependency since we
never block waiting for run_lock while holding wnd->rw_lock.

## Affected

- `Linux >= 57f7979aefdcef66326bda47e07ee0d8be64bf21 < d60f09d2d16c44a797d8cb67015cde2508720506`
- `Linux >= db7fc56646cafe39599a4c21f1398e2bdfd5c185 < 76016d15bbd90caa0ce7765fddf9bde8e943e601`
- `Linux >= 5fc982fe7eca9d0cf7b25832450ebd4f7c8e1c36 < b014372b62237521444ee51384549bdf48b79015`
- `Linux >= 5fc982fe7eca9d0cf7b25832450ebd4f7c8e1c36 < b8d22d9d8260b0f4f4d8e2898c98037c9982ea66`
- `Linux >= 5fc982fe7eca9d0cf7b25832450ebd4f7c8e1c36 < 08ce2fee1b869ecbfbd94e0eb2630e52203a2e03`
- `Linux >= 6.6.66 < 6.6.160`
- `Linux >= 6.12.5 < 6.12.114`
- `Linux 6.13`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.