---
id: CVE-2026-68301
title: 'net: hsr: fix memory leak on slave unregistration by removing synced VLANs'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: hsr: fix memory leak on slave unregistration by removing synced VLANs

  When an HSR master device is brought UP, it auto-adds VLAN 0 via
  vlan_vid0_add(), which prop…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1100242709d5644856131a9dd25d32672ebe7357 <
    ccc822e9e4f09a6c2ca73ad5334570441947f94f
  - >-
    Linux >= a2accc07bdcfb0c7ab2cacdca6a1fe8267816efa <
    79ff0547676acdeceda445c3fce4071b0a887b70
  - >-
    Linux >= 72dbae1f2f2159395089405c6c54632f2613f1be <
    f72c312af6c7897ab0f8a2b5a63f917a207a4143
  - >-
    Linux >= c707d2c5541d2bb94131968ad5dfeb06427a1dba <
    21d48408479a17eb65568a765930adea37e4d804
  - >-
    Linux >= 1a8a63a5305e95519de6f941922dfcd8179f82e5 <
    b5ded444621b6180df9f3d4e07045fc1fc1e8cd9
  - >-
    Linux >= 1a8a63a5305e95519de6f941922dfcd8179f82e5 <
    ae995b8002d3af134560a706c0e111a89e26317c
  - >-
    Linux >= 1a8a63a5305e95519de6f941922dfcd8179f82e5 <
    dcf15eaf5641812f1cfc5e96537380132a7da89d
  - Linux >= 5.15.194 < 5.15.216
  - Linux >= 6.1.153 < 6.1.183
  - Linux >= 6.6.107 < 6.6.148
  - Linux >= 6.12.48 < 6.12.101
  - Linux 6.13
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:46:46.689582Z'
published: '2026-08-10'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T16:55:12.377Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-68301'
references:
  - url: 'https://git.kernel.org/stable/c/ccc822e9e4f09a6c2ca73ad5334570441947f94f'
  - url: 'https://git.kernel.org/stable/c/79ff0547676acdeceda445c3fce4071b0a887b70'
  - url: 'https://git.kernel.org/stable/c/f72c312af6c7897ab0f8a2b5a63f917a207a4143'
  - url: 'https://git.kernel.org/stable/c/21d48408479a17eb65568a765930adea37e4d804'
  - url: 'https://git.kernel.org/stable/c/b5ded444621b6180df9f3d4e07045fc1fc1e8cd9'
  - url: 'https://git.kernel.org/stable/c/ae995b8002d3af134560a706c0e111a89e26317c'
  - url: 'https://git.kernel.org/stable/c/dcf15eaf5641812f1cfc5e96537380132a7da89d'
tags:
  - cve.org
epss: 0.00173
epssPercentile: 0.06708
ingestedAt: '2026-11-06T18:00:12.615Z'
---

## Overview

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

net: hsr: fix memory leak on slave unregistration by removing synced VLANs

When an HSR master device is brought UP, it auto-adds VLAN 0 via
vlan_vid0_add(), which propagates VID 0 to its slave devices (slave A and B).

If a slave device is later unregistered while HSR is active (e.g., during
netns cleanup or interface destruction), hsr_del_port() is called to
detach the slave port from the HSR master. However, hsr_del_port() currently
does not delete the VLAN IDs that were synced to the slave device by HSR.

As a result, the slave device retains a refcount on VID 0 (and any other
synced VLANs). When the slave device is destroyed, its vlan_info /
vlan_vid_info structure remains allocated, leading to a memory leak.

Fix this by calling vlan_vids_del_by_dev(port->dev, master->dev) in
hsr_del_port() before unlinking slave A or slave B ports, matching the
propagation logic in hsr_ndo_vlan_rx_add_vid() / hsr_ndo_vlan_rx_kill_vid()
and the cleanup behavior in bonding and team drivers.

## Affected

- `Linux >= 1100242709d5644856131a9dd25d32672ebe7357 < ccc822e9e4f09a6c2ca73ad5334570441947f94f`
- `Linux >= a2accc07bdcfb0c7ab2cacdca6a1fe8267816efa < 79ff0547676acdeceda445c3fce4071b0a887b70`
- `Linux >= 72dbae1f2f2159395089405c6c54632f2613f1be < f72c312af6c7897ab0f8a2b5a63f917a207a4143`
- `Linux >= c707d2c5541d2bb94131968ad5dfeb06427a1dba < 21d48408479a17eb65568a765930adea37e4d804`
- `Linux >= 1a8a63a5305e95519de6f941922dfcd8179f82e5 < b5ded444621b6180df9f3d4e07045fc1fc1e8cd9`
- `Linux >= 1a8a63a5305e95519de6f941922dfcd8179f82e5 < ae995b8002d3af134560a706c0e111a89e26317c`
- `Linux >= 1a8a63a5305e95519de6f941922dfcd8179f82e5 < dcf15eaf5641812f1cfc5e96537380132a7da89d`
- `Linux >= 5.15.194 < 5.15.216`
- `Linux >= 6.1.153 < 6.1.183`
- `Linux >= 6.6.107 < 6.6.148`
- `Linux >= 6.12.48 < 6.12.101`
- `Linux 6.13`

## Remediation

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