---
id: CVE-2022-49907
title: 'net: mdio: fix undefined behavior in bit shift for __mdiobus_register'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: mdio: fix undefined behavior in bit shift for __mdiobus_register

  Shifting signed 32-bit value by 31 bits is undefined, so changing
  significant bit to unsigned. Th…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c <
    20ed01a7b9af6e6a3c33761eebbb710ea6dd49b7
  - >-
    Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c <
    7006176a3c863e3e353ce1b8a349ef5bb1b9320e
  - >-
    Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c <
    a3fafc974be37319679f36dc4e7cca7db1e02973
  - >-
    Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c <
    4954b5359eb141499492fadfab891e28905509e2
  - >-
    Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c <
    634f066d02bdb22a26da7deb0c7617ab1a65fc9d
  - >-
    Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c <
    985a88bf0b27193522bba7856b1763f428cef19d
  - >-
    Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c <
    6ce6f8f8f6316da6f92afe7490bc2f0b654d68e0
  - >-
    Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c <
    40e4eb324c59e11fcb927aa46742d28aba6ecb8a
  - Linux 2.6.28
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T19:51:22.278697Z'
published: '2025-05-01'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:00:11.220Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2022-49907'
references:
  - url: 'https://git.kernel.org/stable/c/20ed01a7b9af6e6a3c33761eebbb710ea6dd49b7'
  - url: 'https://git.kernel.org/stable/c/7006176a3c863e3e353ce1b8a349ef5bb1b9320e'
  - url: 'https://git.kernel.org/stable/c/a3fafc974be37319679f36dc4e7cca7db1e02973'
  - url: 'https://git.kernel.org/stable/c/4954b5359eb141499492fadfab891e28905509e2'
  - url: 'https://git.kernel.org/stable/c/634f066d02bdb22a26da7deb0c7617ab1a65fc9d'
  - url: 'https://git.kernel.org/stable/c/985a88bf0b27193522bba7856b1763f428cef19d'
  - url: 'https://git.kernel.org/stable/c/6ce6f8f8f6316da6f92afe7490bc2f0b654d68e0'
  - url: 'https://git.kernel.org/stable/c/40e4eb324c59e11fcb927aa46742d28aba6ecb8a'
tags:
  - cve.org
epss: 0.0023
epssPercentile: 0.13834
ingestedAt: '2026-11-05T22:38:31.624Z'
---

## Overview

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

net: mdio: fix undefined behavior in bit shift for __mdiobus_register

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in drivers/net/phy/mdio_bus.c:586:27
left shift of 1 by 31 places cannot be represented in type 'int'
Call Trace:
 <TASK>
 dump_stack_lvl+0x7d/0xa5
 dump_stack+0x15/0x1b
 ubsan_epilogue+0xe/0x4e
 __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
 __mdiobus_register+0x49d/0x4e0
 fixed_mdio_bus_init+0xd8/0x12d
 do_one_initcall+0x76/0x430
 kernel_init_freeable+0x3b3/0x422
 kernel_init+0x24/0x1e0
 ret_from_fork+0x1f/0x30
 </TASK>

## Affected

- `Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c < 20ed01a7b9af6e6a3c33761eebbb710ea6dd49b7`
- `Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c < 7006176a3c863e3e353ce1b8a349ef5bb1b9320e`
- `Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c < a3fafc974be37319679f36dc4e7cca7db1e02973`
- `Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c < 4954b5359eb141499492fadfab891e28905509e2`
- `Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c < 634f066d02bdb22a26da7deb0c7617ab1a65fc9d`
- `Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c < 985a88bf0b27193522bba7856b1763f428cef19d`
- `Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c < 6ce6f8f8f6316da6f92afe7490bc2f0b654d68e0`
- `Linux >= 4fd5f812c23c7deee6425f4a318e85c317cd1d6c < 40e4eb324c59e11fcb927aa46742d28aba6ecb8a`
- `Linux 2.6.28`

## Remediation

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