---
id: CVE-2026-53014
title: >-
  In the Linux kernel, the following vulnerability has been resolved:


  net/sched: act_mirred: fix wrong device for mac_header_xmit check in
  tcf_blockcast_redir


  In tcf_blockcast_redir(), when iterating block ports to redirect

  packets to mu…
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  net/sched: act_mirred: fix wrong device for mac_header_xmit check in
  tcf_blockcast_redir


  In tcf_blockcast_redir(), when iterating block ports to redirect

  packets to mu…
severity: none
published: '2026-06-24'
updated: '2026-07-10'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53014'
references:
  - url: 'https://git.kernel.org/stable/c/4510d140524ca7d6e772db962e013f26f09a63b1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4764953c4b47585eb72797b216b63a831dc0c7e6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7db3e4e03032261b1b519341123fc30d995478ca'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8fda5174286119addd28473fb2ec5bdf521c05a8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00122
epssPercentile: 0.02283
ingestedAt: '2026-07-11T19:15:11.759Z'
---

## Overview

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

net/sched: act_mirred: fix wrong device for mac_header_xmit check in tcf_blockcast_redir

In tcf_blockcast_redir(), when iterating block ports to redirect
packets to multiple devices, the mac_header_xmit flag is queried
from the wrong device. The loop sends to dev_prev but queries
dev_is_mac_header_xmit(dev) — which is the NEXT device in the
iteration, not the one being sent to.

This causes tcf_mirred_to_dev() to make incorrect decisions about
whether to push or pull the MAC header. When the block contains
mixed device types (e.g., an ethernet veth and a tunnel device),
intermediate devices get the wrong mac_header_xmit flag, leading to
skb header corruption. In the worst case, skb_push_rcsum with an
incorrect mac_len can exhaust headroom and panic.

The last device in the loop is handled correctly (line 365-366 uses
dev_is_mac_header_xmit(dev_prev)), confirming this is a copy-paste
oversight for the intermediate devices.

Fix by using dev_prev instead of dev for the mac_header_xmit query,
consistent with the device actually being sent to.

## Remediation

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