---
id: CVE-2025-40347
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: enetc: fix the deadlock of enetc_mdio_lock

  After applying the workaround for err050089, the LS1028A platform
  experiences RCU stalls on RT kernel
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: enetc: fix the deadlock of enetc_mdio_lock

  After applying the workaround for err050089, the LS1028A platform
  experiences RCU stalls on RT kernel. This issue is ca…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
published: '2025-12-16'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40347'
references:
  - url: 'https://git.kernel.org/stable/c/1f92f5bd057a4fad9dab6af17963cdd21e5da6ed'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2781ca82ce8cad263d80b617addb727e6a84c9e5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2e55a49dc3b2a6b23329e4fbbd8a5feb20e220aa'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/50bd33f6b3922a6b760aa30d409cae891cec8fb5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a649161526736f48bcc592e3a412e5bcd7dd9e24'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00528
epssPercentile: 0.43122
ingestedAt: '2026-10-14T13:30:58.436Z'
---

## Overview

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

net: enetc: fix the deadlock of enetc_mdio_lock

After applying the workaround for err050089, the LS1028A platform
experiences RCU stalls on RT kernel. This issue is caused by the
recursive acquisition of the read lock enetc_mdio_lock. Here list some
of the call stacks identified under the enetc_poll path that may lead to
a deadlock:

enetc_poll
  -> enetc_lock_mdio
  -> enetc_clean_rx_ring OR napi_complete_done
     -> napi_gro_receive
        -> enetc_start_xmit
           -> enetc_lock_mdio
           -> enetc_map_tx_buffs
           -> enetc_unlock_mdio
  -> enetc_unlock_mdio

After enetc_poll acquires the read lock, a higher-priority writer attempts
to acquire the lock, causing preemption. The writer detects that a
read lock is already held and is scheduled out. However, readers under
enetc_poll cannot acquire the read lock again because a writer is already
waiting, leading to a thread hang.

Currently, the deadlock is avoided by adjusting enetc_lock_mdio to prevent
recursive lock acquisition.

## Remediation

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