---
id: CVE-2023-53516
title: 'macvlan: add forgotten nla_policy for IFLA_MACVLAN_BC_CUTOFF'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  macvlan: add forgotten nla_policy for IFLA_MACVLAN_BC_CUTOFF

  The previous commit 954d1fa1ac93 ("macvlan: Add netlink attribute for
  broadcast cutoff") added one additio…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 954d1fa1ac93aa8a66f7d9a9ba545cf7f020d348 <
    79f44709aa7a744fbfbadd4aef678443290c6991
  - >-
    Linux >= 954d1fa1ac93aa8a66f7d9a9ba545cf7f020d348 <
    55cef78c244d0d076f5a75a35530ca63c92f4426
  - Linux 6.4
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T20:22:56.453109Z'
published: '2025-10-01'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:31:13.012Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-53516'
references:
  - url: 'https://git.kernel.org/stable/c/79f44709aa7a744fbfbadd4aef678443290c6991'
  - url: 'https://git.kernel.org/stable/c/55cef78c244d0d076f5a75a35530ca63c92f4426'
tags:
  - cve.org
epss: 0.00146
epssPercentile: 0.03865
ingestedAt: '2026-11-05T22:38:31.805Z'
---

## Overview

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

macvlan: add forgotten nla_policy for IFLA_MACVLAN_BC_CUTOFF

The previous commit 954d1fa1ac93 ("macvlan: Add netlink attribute for
broadcast cutoff") added one additional attribute named
IFLA_MACVLAN_BC_CUTOFF to allow broadcast cutfoff.

However, it forgot to describe the nla_policy at macvlan_policy
(drivers/net/macvlan.c). Hence, this suppose NLA_S32 (4 bytes) integer
can be faked as empty (0 bytes) by a malicious user, which could leads
to OOB in heap just like CVE-2023-3773.

To fix it, this commit just completes the nla_policy description for
IFLA_MACVLAN_BC_CUTOFF. This enforces the length check and avoids the
potential OOB read.

## Affected

- `Linux >= 954d1fa1ac93aa8a66f7d9a9ba545cf7f020d348 < 79f44709aa7a744fbfbadd4aef678443290c6991`
- `Linux >= 954d1fa1ac93aa8a66f7d9a9ba545cf7f020d348 < 55cef78c244d0d076f5a75a35530ca63c92f4426`
- `Linux 6.4`

## Remediation

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