---
id: CVE-2026-99054
title: 'tipc: destroy topsrv workqueues before closing connections'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  tipc: destroy topsrv workqueues before closing connections

  tipc_topsrv_stop() closed subscriber connections while the topology
  server's send and receive workqueues wer…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f <
    7f796bb3b440d7f1b14c0e3b520462eb34f553af
  - >-
    Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f <
    da9c16568bc79140a54c1f5fcf07a0305df47b37
  - >-
    Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f <
    0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e
  - >-
    Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f <
    fb717c536af2aafeca520ff11d1e0f25f7ab8fa9
  - >-
    Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f <
    3acdd44385bc7e2e57605e073691ce69cc5a960d
  - Linux 3.11
published: '2026-10-23'
updated: '2026-10-24'
sourceUpdated: '2026-10-24T14:10:14.659Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-99054'
references:
  - url: 'https://git.kernel.org/stable/c/7f796bb3b440d7f1b14c0e3b520462eb34f553af'
  - url: 'https://git.kernel.org/stable/c/da9c16568bc79140a54c1f5fcf07a0305df47b37'
  - url: 'https://git.kernel.org/stable/c/0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e'
  - url: 'https://git.kernel.org/stable/c/fb717c536af2aafeca520ff11d1e0f25f7ab8fa9'
  - url: 'https://git.kernel.org/stable/c/3acdd44385bc7e2e57605e073691ce69cc5a960d'
tags:
  - cve.org
epss: 0.00209
epssPercentile: 0.10489
ingestedAt: '2026-10-23T13:24:55.520Z'
---

## Overview

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

tipc: destroy topsrv workqueues before closing connections

tipc_topsrv_stop() closed subscriber connections while the topology
server's send and receive workqueues were still running. Socket
callbacks and subscription events could then queue more work, and
in-flight send/recv work could drop the last connection reference
during the conn_idr walk.

That race produced several teardown failures: refcount_t addition on
0 from conn_get() on a connection whose release was blocked on
idr_lock, a subsequent use-after-free in tipc_conn_close(),
queue_work() on an already destroyed workqueue from the listener
data-ready callback, and an RCU stall in tipc_topsrv_exit_net()
while the walk spun under idr_lock.

Clear srv->listener under idr_lock so it acts as a shutdown flag,
skip queue_work() once it is NULL, destroy the workqueues to flush
in-flight work, and only then close the remaining connections.
Refuse tipc_conn_lookup() after that flag is cleared, and drop
idr_lock when the teardown walk finds no connection, so an
in-flight subscription event cannot pin idr_in_use while the
walk holds the lock.

v3 supersedes the narrower in-thread diff Tung Quang Nguyen
posted on 2026-09-23. It keeps his teardown order and adds the
lookup refusal and the empty-idr unlock.

## Affected

- `Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f < 7f796bb3b440d7f1b14c0e3b520462eb34f553af`
- `Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f < da9c16568bc79140a54c1f5fcf07a0305df47b37`
- `Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f < 0af8780bdfdfc91fb9127bddb9c48fab67dc9d9e`
- `Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f < fb717c536af2aafeca520ff11d1e0f25f7ab8fa9`
- `Linux >= c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f < 3acdd44385bc7e2e57605e073691ce69cc5a960d`
- `Linux 3.11`

## Remediation

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