---
id: CVE-2026-90155
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ksmbd: detach blocked lock requests before freeing

  A file_lock retained by ksmbd for byte-range lock bookkeeping can still
  be part of the VFS blocked-request graph
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ksmbd: detach blocked lock requests before freeing

  A file_lock retained by ksmbd for byte-range lock bookkeeping can still
  be part of the VFS blocked-request graph. In…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= d63528eb0d43c4796c42aad56889dec12cf4e122 <
    514a0b2bc949963497e66cacd433f65dc768a71d
  - >-
    Linux >= d63528eb0d43c4796c42aad56889dec12cf4e122 <
    215e8816b1ac25176d911abb8704390413ccee4b
  - Linux 5.15
published: '2026-09-17'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T11:17:58.390'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90155'
references:
  - url: 'https://git.kernel.org/stable/c/215e8816b1ac25176d911abb8704390413ccee4b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/514a0b2bc949963497e66cacd433f65dc768a71d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f77d2accafca529e0ea3f979eb6e6cf1dac05c90'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d20d3f6ad8b0b6f4e1bb32cdf7eca251962e8f04'
  - url: 'https://git.kernel.org/stable/c/d31db79cfaa9fce6649772ad279779473ba8aef9'
tags:
  - nvd
  - cve.org
epss: 0.00209
epssPercentile: 0.10926
ingestedAt: '2026-09-17T16:21:47.874Z'
---

## Overview

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

ksmbd: detach blocked lock requests before freeing

A file_lock retained by ksmbd for byte-range lock bookkeeping can still
be part of the VFS blocked-request graph. In particular, the VFS can
chain a new waiter below an already blocked request through
flc_blocked_requests. The ksmbd_file reference count does not cover that
graph.

Both __ksmbd_close_fd() and the cross-request unlock path free these
retained file_lock objects directly. If a dependent waiter is still
attached, locks_release_private() hits
BUG_ON(!list_empty(&flc->flc_blocked_requests)). The same lifetime
mismatch can leave a freed ksmbd_lock reachable through its request-local
llist.

Detach the file_lock from the blocked-request graph before freeing it in
the close, cross-request unlock, and rollback paths. locks_delete_block()
also wakes requests chained below the object. Remove llist when a
completed lock is published so a globally visible ksmbd_lock no longer
points into the submitting worker's stack.

## Remediation

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