---
id: CVE-2024-47660
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fsnotify: clear PARENT_WATCHED flags lazily

  In some setups directories can have many (usually negative) dentries.
  Hence __fsnotify_update_child_dentry_flags() function…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fsnotify: clear PARENT_WATCHED flags lazily

  In some setups directories can have many (usually negative) dentries.
  Hence __fsnotify_update_child_dentry_flags() function…
severity: medium
cvss: 4.7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-362
vendor: linux
product: linux_kernel
affected:
  - linux_kernel < 5.10.226
  - 'linux_kernel >= 5.11, < 5.15.167'
  - 'linux_kernel >= 5.16, < 6.1.109'
  - 'linux_kernel >= 6.2, < 6.6.50'
  - 'linux_kernel >= 6.7, < 6.10.9'
patched:
  - linux_kernel 6.10.9
published: '2024-10-09'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T01:18:53.990'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-47660'
references:
  - url: 'https://git.kernel.org/stable/c/172e422ffea20a89bfdc672741c1aad6fbb5044e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3f3ef1d9f66b93913ce2171120d9226b55acd41d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7ef1d2e240c32b1f337a37232d037b07e3919e1a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d8c42405fc3507cc43ba7e4986a773c3fc633f6e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f9a48bc3dd9099935751458a5bbbea4b7c28abc8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fc1b1e135c3f72382f792e6c319fc088d5523ad5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-265688.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-355557.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.0016
epssPercentile: 0.05072
ingestedAt: '2026-10-15T03:30:12.744Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2024-10-10T13:23:14.677657Z'
---

## Overview

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

fsnotify: clear PARENT_WATCHED flags lazily

In some setups directories can have many (usually negative) dentries.
Hence __fsnotify_update_child_dentry_flags() function can take a
significant amount of time. Since the bulk of this function happens
under inode->i_lock this causes a significant contention on the lock
when we remove the watch from the directory as the
__fsnotify_update_child_dentry_flags() call from fsnotify_recalc_mask()
races with __fsnotify_update_child_dentry_flags() calls from
__fsnotify_parent() happening on children. This can lead upto softlockup
reports reported by users.

Fix the problem by calling fsnotify_update_children_dentry_flags() to
set PARENT_WATCHED flags only when parent starts watching children.

When parent stops watching children, clear false positive PARENT_WATCHED
flags lazily in __fsnotify_parent() for each accessed child.

## Affected

- `linux_kernel < 5.10.226`
- `linux_kernel >= 5.11, < 5.15.167`
- `linux_kernel >= 5.16, < 6.1.109`
- `linux_kernel >= 6.2, < 6.6.50`
- `linux_kernel >= 6.7, < 6.10.9`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.10.9`