---
id: CVE-2025-38736
title: 'net: usb: asix_devices: Fix PHY address mask in MDIO bus initialization'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: usb: asix_devices: Fix PHY address mask in MDIO bus initialization

  Syzbot reported shift-out-of-bounds exception on MDIO bus initialization.

  The PHY address shou…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 75947d3200de98a9ded9ad8972e02f1a177097fe <
    fcb4ce9f729c1d08e53abf9d449340e24c3edee6
  - >-
    Linux >= 59ed6fbdb1bc03316e09493ffde7066f031c7524 <
    8f141f2a4f2ef8ca865d5921574c3d6535e00a49
  - >-
    Linux >= ccef5ee4adf56472aa26bdd1f821a6d0cd06089a <
    748da80831221ae24b4bc8d7ffb22acd5712a341
  - >-
    Linux >= ee2cd40b0bb46056949a2319084a729d95389386 <
    22042ffedd8c2c6db08ccdd6d4273068eddd3c5c
  - >-
    Linux >= ad1f8313aeec0115f9978bd2d002ef4a8d96c773 <
    523eab02fce458fa6d3c51de5bb055800986953e
  - >-
    Linux >= 4faff70959d51078f9ee8372f8cff0d7045e4114 <
    24ef2f53c07f273bad99173e27ee88d44d135b1c
  - Linux a754ab53993b1585132e871c5d811167ad3c52ff
  - Linux >= 6.15.11 < 6.16
  - Linux >= 6.12.43 < 6.12.44
  - Linux >= 6.16.2 < 6.16.4
published: '2025-09-05'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:42:04.597Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-38736'
references:
  - url: 'https://git.kernel.org/stable/c/fcb4ce9f729c1d08e53abf9d449340e24c3edee6'
  - url: 'https://git.kernel.org/stable/c/8f141f2a4f2ef8ca865d5921574c3d6535e00a49'
  - url: 'https://git.kernel.org/stable/c/748da80831221ae24b4bc8d7ffb22acd5712a341'
  - url: 'https://git.kernel.org/stable/c/22042ffedd8c2c6db08ccdd6d4273068eddd3c5c'
  - url: 'https://git.kernel.org/stable/c/523eab02fce458fa6d3c51de5bb055800986953e'
  - url: 'https://git.kernel.org/stable/c/24ef2f53c07f273bad99173e27ee88d44d135b1c'
tags:
  - cve.org
epss: 0.00164
epssPercentile: 0.04947
ingestedAt: '2026-09-08T15:33:26.997Z'
---

## Overview

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

net: usb: asix_devices: Fix PHY address mask in MDIO bus initialization

Syzbot reported shift-out-of-bounds exception on MDIO bus initialization.

The PHY address should be masked to 5 bits (0-31). Without this
mask, invalid PHY addresses could be used, potentially causing issues
with MDIO bus operations.

Fix this by masking the PHY address with 0x1f (31 decimal) to ensure
it stays within the valid range.

## Affected

- `Linux >= 75947d3200de98a9ded9ad8972e02f1a177097fe < fcb4ce9f729c1d08e53abf9d449340e24c3edee6`
- `Linux >= 59ed6fbdb1bc03316e09493ffde7066f031c7524 < 8f141f2a4f2ef8ca865d5921574c3d6535e00a49`
- `Linux >= ccef5ee4adf56472aa26bdd1f821a6d0cd06089a < 748da80831221ae24b4bc8d7ffb22acd5712a341`
- `Linux >= ee2cd40b0bb46056949a2319084a729d95389386 < 22042ffedd8c2c6db08ccdd6d4273068eddd3c5c`
- `Linux >= ad1f8313aeec0115f9978bd2d002ef4a8d96c773 < 523eab02fce458fa6d3c51de5bb055800986953e`
- `Linux >= 4faff70959d51078f9ee8372f8cff0d7045e4114 < 24ef2f53c07f273bad99173e27ee88d44d135b1c`
- `Linux a754ab53993b1585132e871c5d811167ad3c52ff`
- `Linux >= 6.15.11 < 6.16`
- `Linux >= 6.12.43 < 6.12.44`
- `Linux >= 6.16.2 < 6.16.4`

## Remediation

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