---
id: CVE-2026-98301
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: bridge: mst: move switchdev call outside rcu

  This is a follow-up of one of sashiko's pre-existing bug reports.
  br_mst_set_state() calls switchdev_port_attr_set() …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: bridge: mst: move switchdev call outside rcu

  This is a follow-up of one of sashiko's pre-existing bug reports.
  br_mst_set_state() calls switchdev_port_attr_set() …
severity: high
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 8ca9a750fc711911ef616ceb627d07357b04545e <
    b9661fd2423fc25e91e0517ecc0b6156ad83e3a8
  - >-
    Linux >= 4488617e5e995a09abe4d81add5fb165674edb59 <
    6b431b63219853eef4054e2f1cb073d2ca2059b4
  - >-
    Linux >= 3a7c1661ae1383364cd6092d851f5e5da64d476b <
    abf734d150c61acfdfee102169d0e5d1c482e285
  - >-
    Linux >= 3a7c1661ae1383364cd6092d851f5e5da64d476b <
    d5c4ee1fa4e83a12afc051c831936cd8e006cde3
  - >-
    Linux >= 3a7c1661ae1383364cd6092d851f5e5da64d476b <
    c40ed3e884c8dc0350f26484030438ef24208ff1
  - >-
    Linux >= 3a7c1661ae1383364cd6092d851f5e5da64d476b <
    18a6fe05fb6e18de29fa90d388bb34044114b3d8
  - Linux a2b01e65d9ba8af2bb086d3b7288ca53a07249ac
  - Linux e43dd2b1ec746e105b7db5f9ad6ef14685a615a4
  - Linux >= 6.1.93 < 6.1.189
  - Linux >= 6.6.33 < 6.6.158
  - Linux >= 6.8.12 < 6.9
  - Linux >= 6.9.3 < 6.10
  - Linux 6.10
published: '2026-10-06'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T09:18:21.037'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98301'
references:
  - url: 'https://git.kernel.org/stable/c/18a6fe05fb6e18de29fa90d388bb34044114b3d8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6b431b63219853eef4054e2f1cb073d2ca2059b4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/abf734d150c61acfdfee102169d0e5d1c482e285'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b9661fd2423fc25e91e0517ecc0b6156ad83e3a8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c40ed3e884c8dc0350f26484030438ef24208ff1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d5c4ee1fa4e83a12afc051c831936cd8e006cde3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98301.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98301'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2546493'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98301'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98301'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98301.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-10-06T08:50:17.415Z'
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe:
  - CWE-821
epss: 0.0018
epssPercentile: 0.07537
---

## Overview

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

net: bridge: mst: move switchdev call outside rcu

This is a follow-up of one of sashiko's pre-existing bug reports.
br_mst_set_state() calls switchdev_port_attr_set() for nonzero MSTIs
while holding rcu_read_lock() which invokes the blocking switchdev
notifier chain and may sleep. Nonzero MSTI changes come from netlink
with rtnl held. Move the switchdev call before entering the rcu section and
assert that rtnl is held.

The call cannot be deferred because netlink needs its error and extack.
Also DSA reads the old bridge MST state during the callback and checks it.
A deferred callback will be late and will see the updated state.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-11 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98301.json)