---
id: CVE-2026-98881
title: 'net: bridge: remove stale rcu_barrier() in br_multicast_dev_del()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: bridge: remove stale rcu_barrier() in br_multicast_dev_del()

  This rcu_barrier() came from a time call_rcu() calls were used in
  net/bridge/br_multicast.c.

  Now kfr…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    35f9f11740515a10b084adfb1ce691351f2452ab
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    0443f6aac6bf6a91e406273fdda11497cef6ad07
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    ac0e823a228f94ad9d7a3d876cc07e59a7afb806
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    f0018acf0b66f93a292667c9a9c2a26c570cf270
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    372ee8fbe0f796031c60f676ec90f0788c26523d
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    39679927fa7aaf4601119f7234342d1b5d4f6f84
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    25ae123db10ba9ab890b56bcdb0a4363aee8529a
  - Linux < 5.10.271
  - Linux < 5.15.222
  - Linux < 6.1.189
  - Linux < 6.6.158
  - Linux < 6.12.111
  - Linux < 6.18.53
  - Linux (all versions)
published: '2026-10-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T11:37:32.327Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98881'
references:
  - url: 'https://git.kernel.org/stable/c/35f9f11740515a10b084adfb1ce691351f2452ab'
  - url: 'https://git.kernel.org/stable/c/0443f6aac6bf6a91e406273fdda11497cef6ad07'
  - url: 'https://git.kernel.org/stable/c/ac0e823a228f94ad9d7a3d876cc07e59a7afb806'
  - url: 'https://git.kernel.org/stable/c/f0018acf0b66f93a292667c9a9c2a26c570cf270'
  - url: 'https://git.kernel.org/stable/c/372ee8fbe0f796031c60f676ec90f0788c26523d'
  - url: 'https://git.kernel.org/stable/c/39679927fa7aaf4601119f7234342d1b5d4f6f84'
  - url: 'https://git.kernel.org/stable/c/25ae123db10ba9ab890b56bcdb0a4363aee8529a'
tags:
  - cve.org
ingestedAt: '2026-10-23T13:24:55.582Z'
---

## Overview

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

net: bridge: remove stale rcu_barrier() in br_multicast_dev_del()

This rcu_barrier() came from a time call_rcu() calls were used in
net/bridge/br_multicast.c.

Now kfree_rcu() is there, we can remove this problematic rcu_barrier()
which causes extreme RTNL pressure in many syzbot reports.

INFO: task syz-executor:77945 is blocked on a mutex likely owned by task kworker/u1024:5:36537.
task:kworker/u1024:5 state:D stack:24616 pid:36537 tgid:36537 ppid:2      task_flags:0x4208060 flags:0x00080000 last_sleep:612797637337
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
  [<ffffffff81914eaa>] context_switch+0xf2a/0x1730 kernel/sched/core.c:6483
  [<ffffffff81201143>] __schedule+0x1133/0x43a0 kernel/sched/core.c:8411
  [<ffffffff8120446b>] __schedule_loop kernel/sched/core.c:8514 [inline]
  [<ffffffff8120446b>] schedule+0xab/0x260 kernel/sched/core.c:8529
  [<ffffffff8121a093>] schedule_timeout+0xc3/0x2b0 kernel/time/sleep_timeout.c:75
  [<ffffffff81205347>] do_wait_for_common kernel/sched/completion.c:100 [inline]
  [<ffffffff81205347>] __wait_for_common kernel/sched/completion.c:121 [inline]
  [<ffffffff81205347>] wait_for_common kernel/sched/completion.c:132 [inline]
  [<ffffffff81205347>] wait_for_completion+0x2c7/0x5d0 kernel/sched/completion.c:153
  [<ffffffff81b8f27f>] rcu_barrier+0x49f/0x620 kernel/rcu/tree.c:3888
  [<ffffffff860091b3>] br_multicast_dev_del+0x303/0x350 net/bridge/br_multicast.c:4459
  [<ffffffff85fb5dbc>] br_dev_uninit+0x1c/0x40 net/bridge/br_device.c:157
  [<ffffffff8568058c>] unregister_netdevice_many_notify+0x1c1c/0x2300 net/core/dev.c:12599
  [<ffffffff8562be43>] ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
  [<ffffffff8562be43>] ops_undo_list+0x3d3/0x940 net/core/net_namespace.c:248

## Affected

- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 35f9f11740515a10b084adfb1ce691351f2452ab`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 0443f6aac6bf6a91e406273fdda11497cef6ad07`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ac0e823a228f94ad9d7a3d876cc07e59a7afb806`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f0018acf0b66f93a292667c9a9c2a26c570cf270`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 372ee8fbe0f796031c60f676ec90f0788c26523d`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 39679927fa7aaf4601119f7234342d1b5d4f6f84`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 25ae123db10ba9ab890b56bcdb0a4363aee8529a`
- `Linux < 5.10.271`
- `Linux < 5.15.222`
- `Linux < 6.1.189`
- `Linux < 6.6.158`
- `Linux < 6.12.111`
- `Linux < 6.18.53`
- `Linux (all versions)`

## Remediation

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