---
id: CVE-2026-98347
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  IB/IPoIB: Avoid restoring OPER_UP after multicast flush

  ipoib_ib_dev_flush_light() temporarily clears IPOIB_FLAG_OPER_UP to
  prevent multicast joins while ipoib_mcast_d…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  IB/IPoIB: Avoid restoring OPER_UP after multicast flush

  ipoib_ib_dev_flush_light() temporarily clears IPOIB_FLAG_OPER_UP to
  prevent multicast joins while ipoib_mcast_d…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 344bacca8cd811809fc33a249f2738ab757d327f <
    f973769fb7cb33ba0d4a64b7dcfee0cabaead938
  - >-
    Linux >= 344bacca8cd811809fc33a249f2738ab757d327f <
    b72f38929f4b5aa83161fd3b22a7327207e51ec5
  - >-
    Linux >= 344bacca8cd811809fc33a249f2738ab757d327f <
    1b11e4b55b41d9e69a8e8d07622614202e2eaca9
  - >-
    Linux >= 344bacca8cd811809fc33a249f2738ab757d327f <
    326f7d34bd7e64de535566b65c0533b640df5a81
  - >-
    Linux >= 344bacca8cd811809fc33a249f2738ab757d327f <
    5ad925d45f28464a5e043c9620880bb6a030da89
  - >-
    Linux >= 344bacca8cd811809fc33a249f2738ab757d327f <
    188b334a6db36a8e0bfaaf59bc4020639a0f3aad
  - >-
    Linux >= 344bacca8cd811809fc33a249f2738ab757d327f <
    1ff3add37c329704ec46181b4ae4f00f9f16ce6f
  - >-
    Linux >= 344bacca8cd811809fc33a249f2738ab757d327f <
    9a141d3dc869d18b2eab35e999f4790a9b84e40f
  - Linux a289c65ca49d2680a3d797e633e57a45573d1df2
  - Linux b81459c78935e4579a577b2366c5f8878d3c7fee
  - Linux 8a9d8dc9ce83a90bfbbe69181acc4cf1beff46f5
  - Linux dfe809702a11bd7fb91c882fb55620e39ce22109
  - Linux 87160fb51bc343793cc8f5f031a87f1a35aecb82
  - Linux 749fd55dd210f9676f0d445a6efaaa3bec65174a
  - Linux >= 3.2.84 < 3.3
  - Linux >= 3.10.105 < 3.11
  - Linux >= 3.12.65 < 3.13
  - Linux >= 3.16.39 < 3.17
  - Linux >= 4.4.24 < 4.5
  - Linux >= 4.7.7 < 4.8
  - Linux 4.8
published: '2026-10-06'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T09:18:27.773'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98347'
references:
  - url: 'https://git.kernel.org/stable/c/188b334a6db36a8e0bfaaf59bc4020639a0f3aad'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1b11e4b55b41d9e69a8e8d07622614202e2eaca9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1ff3add37c329704ec46181b4ae4f00f9f16ce6f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/326f7d34bd7e64de535566b65c0533b640df5a81'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5ad925d45f28464a5e043c9620880bb6a030da89'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9a141d3dc869d18b2eab35e999f4790a9b84e40f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b72f38929f4b5aa83161fd3b22a7327207e51ec5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f973769fb7cb33ba0d4a64b7dcfee0cabaead938'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-06T08:50:17.397Z'
---

## Overview

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

IB/IPoIB: Avoid restoring OPER_UP after multicast flush

ipoib_ib_dev_flush_light() temporarily clears IPOIB_FLAG_OPER_UP to
prevent multicast joins while ipoib_mcast_dev_flush() is running, and
restores the flag afterwards if it was previously set.

This restore races with ipoib_ib_dev_down(). If the interface is brought
down while the flush is in progress, ipoib_ib_dev_down() clears
IPOIB_FLAG_OPER_UP, but the flush path may set it again after the device
has already gone down.

Since commit 894021a75291 ("IB/ipoib: Make the carrier_on_task race
aware"), ipoib_mcast_carrier_on_task() relies on IPOIB_FLAG_OPER_UP
being cleared to terminate its rtnl_trylock() retry loop. If the flag is
left set after shutdown, the workqueue retries forever, causing teardown
to deadlock when ipoib_ndo_uninit() waits in destroy_workqueue() while
holding RTNL.

Instead of overloading IPOIB_FLAG_OPER_UP to block multicast joins
during a light flush, introduce a dedicated IPOIB_FLAG_MCAST_FLUSH flag.
Use it together with IPOIB_FLAG_OPER_UP to determine whether multicast
joins are allowed, avoiding the race with device shutdown.

## Remediation

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