---
id: CVE-2026-64218
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  batman-adv: bla: fix report_work leak on backbone_gw purge

  batadv_bla_purge_backbone_gw() removes stale backbone gateway entries,
  but fails to properly handle their as…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  batman-adv: bla: fix report_work leak on backbone_gw purge

  batadv_bla_purge_backbone_gw() removes stale backbone gateway entries,
  but fails to properly handle their as…
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'
published: '2026-07-24'
updated: '2026-07-27'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64218'
references:
  - url: 'https://git.kernel.org/stable/c/0459430add32ea41f3e2ef9351610e6d33627a6b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3423a45e5c3d3c5129f88143a9a969787d7d5a0a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/48663158222b3b7f6ee6791a67d512ede7fc94bb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/95a7034661274cf5985708bd2f6d86ee46f88fa9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c6de1a5a9c406e30b91f1515a6ce05cc84023baa'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ce2c0ee4d76d5ee4b391fe0e31334361e25030ec'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/eeddd7bab3d59c1e98642a204141f8c5d6194707'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f1303adb1e59582f76c22798a2e2e150e054a9e7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64218.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-64218'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2506786'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-64218'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64218'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2026072415-CVE-2026-64218-ea1d@gregkh/T
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.00176
epssPercentile: 0.0626
ingestedAt: '2026-07-27T06:16:49.109Z'
vendor: Red Hat
product: Red Hat OpenShift Container Platform 4
affected:
  - enterprise_linux 10
  - enterprise_linux_for_nvidia 26
  - openshift_container_platform 4
cwe:
  - CWE-825
---

## Overview

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

batman-adv: bla: fix report_work leak on backbone_gw purge

batadv_bla_purge_backbone_gw() removes stale backbone gateway entries,
but fails to properly handle their associated report_work:

- If report_work is running, the purge must wait for it to finish before
  freeing the backbone_gw, otherwise the worker may access freed memory
  (e.g. bat_priv).
- If report_work is pending, the purge must cancel it and release the
  reference held for that pending work item.

The previous implementation called hlist_for_each_entry_safe() inside a
spin_lock_bh() section, but cancel_work_sync() may sleep and therefore
cannot be called from within a spinlock-protected region.

Restructure the loop to handle one entry per spinlock critical section:
acquire the lock, find the next entry to purge, remove it from the hash
list, then release the lock before calling cancel_work_sync() and
dropping the hash_entry reference. Repeat until no more entries require
purging.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux for NVIDIA 26, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux for NVIDIA 26, Red Hat Enterprise Linux 10, Red Hat OpenShift Container Platform 4 · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-64218.json)