---
id: CVE-2026-90279
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  md/raid5: round bitmap stripes with sector division

  raid5_bitmap_sector_map() aligns the array range to full RAID5 stripe
  widths before converting it to component sect…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  md/raid5: round bitmap stripes with sector division

  raid5_bitmap_sector_map() aligns the array range to full RAID5 stripe
  widths before converting it to component sect…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= b29e6400be51c214a0ad30dce937348b57abe33a <
    9d7490007707f90691911385365bd1d691d99225
  - >-
    Linux >= aa8e15d69f5c0044d5bff61844e163aacc4ac172 <
    cab7d949b18b2f1cd625689dc16c5f81236bac93
  - >-
    Linux >= 9c89f604476cf15c31fbbdb043cff7fbf1dbe0cb <
    02c10581866d08822c6348e299881485fc546185
  - >-
    Linux >= 9c89f604476cf15c31fbbdb043cff7fbf1dbe0cb <
    ccbdc483eb041eef809e9ff223d1ad63518a2c52
  - >-
    Linux >= 9c89f604476cf15c31fbbdb043cff7fbf1dbe0cb <
    17ea021ae74987d6064c8195c4922fa025753892
  - Linux a41a0df5d7638acf15e723ad985980b4f7ff9383
  - Linux >= 6.6.79 < 6.6.157
  - Linux >= 6.12.13 < 6.12.110
  - Linux >= 6.13.2 < 6.14
  - Linux 6.14
published: '2026-09-17'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T17:17:24.567'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90279'
references:
  - url: 'https://git.kernel.org/stable/c/02c10581866d08822c6348e299881485fc546185'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/17ea021ae74987d6064c8195c4922fa025753892'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9d7490007707f90691911385365bd1d691d99225'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cab7d949b18b2f1cd625689dc16c5f81236bac93'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ccbdc483eb041eef809e9ff223d1ad63518a2c52'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-17T16:21:47.835Z'
epss: 0.002
epssPercentile: 0.08781
---

## Overview

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

md/raid5: round bitmap stripes with sector division

raid5_bitmap_sector_map() aligns the array range to full RAID5 stripe
widths before converting it to component sectors. That width is
chunk_sectors multiplied by the number of data disks, and it is not
always a power of two.

Reproduce with a 4-disk RAID5, 1024-sector chunks, and three data disks.
The full-stripe width is 3072 sectors. For a one-sector write at array
sector 3072, correct rounding gives array range [3072, 6144), which maps
to component range [1024, 2048). The old round_down()/round_up() logic
instead gives [1024, 4096), which maps to [0, 1024).

Use sector_div() based arithmetic so the rounded range is aligned to the
actual RAID5 stripe width.

The deterministic mapper test now reports the fixed component range as
[1024, 2048), while the old mask-based range was [0, 1024).

## Remediation

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