---
id: CVE-2026-98585
title: 'eth: fbnic: Avoid rounding zero ring sizes'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  eth: fbnic: Avoid rounding zero ring sizes

  roundup_pow_of_two() is undefined for zero. ethtool permits a zero ring
  size to reach the driver, where the minimum-size che…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 6cbf18a05c06090d867ef417a2a30b214d42d171 <
    92c9f2ea634d92adff5403d231ebeda683c5685a
  - >-
    Linux >= 6cbf18a05c06090d867ef417a2a30b214d42d171 <
    491aa3167ae02f219cb2d2de6f4196d28dca03be
  - >-
    Linux >= 6cbf18a05c06090d867ef417a2a30b214d42d171 <
    0160953d8eec75c3c55562158c46442ff1fd410b
  - Linux 6.15
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:18:58.018Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98585'
references:
  - url: 'https://git.kernel.org/stable/c/92c9f2ea634d92adff5403d231ebeda683c5685a'
  - url: 'https://git.kernel.org/stable/c/491aa3167ae02f219cb2d2de6f4196d28dca03be'
  - url: 'https://git.kernel.org/stable/c/0160953d8eec75c3c55562158c46442ff1fd410b'
tags:
  - cve.org
ingestedAt: '2026-10-18T15:45:12.251Z'
---

## Overview

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

eth: fbnic: Avoid rounding zero ring sizes

roundup_pow_of_two() is undefined for zero. ethtool permits a zero ring
size to reach the driver, where the minimum-size check should reject it.

Leave zero unchanged while rounding nonzero ring sizes. The minimum-size
check then rejects zero deterministically without changing the established
behavior for other values.

## Affected

- `Linux >= 6cbf18a05c06090d867ef417a2a30b214d42d171 < 92c9f2ea634d92adff5403d231ebeda683c5685a`
- `Linux >= 6cbf18a05c06090d867ef417a2a30b214d42d171 < 491aa3167ae02f219cb2d2de6f4196d28dca03be`
- `Linux >= 6cbf18a05c06090d867ef417a2a30b214d42d171 < 0160953d8eec75c3c55562158c46442ff1fd410b`
- `Linux 6.15`

## Remediation

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