---
id: CVE-2026-89948
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  batman-adv: bla: fix freeing of claims on meshif deletion

  When the mesh interface is getting deleted, then
  batadv_bla_del_backbone_claims() (via batadv_bla_purge_backb…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  batman-adv: bla: fix freeing of claims on meshif deletion

  When the mesh interface is getting deleted, then
  batadv_bla_del_backbone_claims() (via batadv_bla_purge_backb…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 <
    844a95a734f178d56c7acce14c5cce2cecff7e1a
  - >-
    Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 <
    baeb1a28fd8e2f68193650d3664a8cd1adfd85c6
  - >-
    Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 <
    aacffa780a37e06cd5a13d33740a6e96c3a67e6c
  - >-
    Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 <
    76aedcde5a2489cc971d4d1e396e784a49565e96
  - >-
    Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 <
    f50edb69082a8ba990cc23d642089829f99afe6a
  - >-
    Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 <
    871acdf97f64cee8398f72b88b89e8b4f4816dbe
  - >-
    Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 <
    9a0c47023d3254048a1588534755d4476bcc3abc
  - >-
    Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 <
    8d128c932bced74e3b1625ba3d7c78ef122a88a7
  - Linux 3.5
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T11:17:04.890'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89948'
references:
  - url: 'https://git.kernel.org/stable/c/76aedcde5a2489cc971d4d1e396e784a49565e96'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/844a95a734f178d56c7acce14c5cce2cecff7e1a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/871acdf97f64cee8398f72b88b89e8b4f4816dbe'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8d128c932bced74e3b1625ba3d7c78ef122a88a7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9a0c47023d3254048a1588534755d4476bcc3abc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/aacffa780a37e06cd5a13d33740a6e96c3a67e6c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/baeb1a28fd8e2f68193650d3664a8cd1adfd85c6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f50edb69082a8ba990cc23d642089829f99afe6a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-16T10:53:53.963Z'
epss: 0.00211
epssPercentile: 0.11589
---

## Overview

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

batman-adv: bla: fix freeing of claims on meshif deletion

When the mesh interface is getting deleted, then
batadv_bla_del_backbone_claims() (via batadv_bla_purge_backbone_gw()) could
make sure that all claims gets removed. But this function is only executed
when bat_priv->bla.claim_hash is not NULL. And since batadv_bla_free() is
always setting it to NULL before it is (indirectly) called, it was never
actually executed.

But the batadv_bla_purge_claims() -> batadv_handle_unclaim() is at the
moment too fragile because the BLA code is not handling the rehashing in
batadv_bla_update_orig_address(). The stored backbone address doesn't have
to be the one actually used for the hash bucket selection during the
initial adding of the backbone. The batadv_handle_unclaim() can therefore
fail to find the respective backbone for the unclaim and then stop the
deletion.

But the actual backbone_gw object is not needed for the unclaim because all
relevant information is always provided by the caller. And the check for
the existence of the backbone_gw doesn't provide any additional security
check for the deletion of a claim.

## Remediation

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