Cloudanix VulnDB

CVE-2026-90390

None

CVSS

—

EPSS

0.2%

Published

Sep 17, 2026

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A Linux storage bug can accidentally pause certain disk arrays and leave them paused, stopping programs from reading or writing data until someone fixes it.

Exploitation
Local Privilege
Attacker needs
Low Privilege
Complexity
Low
Impact
Denial Of Service
Component
OS kernel
Class
Other
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

The flaw leaves a RAID array suspended after an error in backlog_store() when no write-mostly device is present, preventing all subsequent I/O operations on the md device.

Why it matters to the business

Linux systems using software RAID may experience persistent I/O blocking on affected arrays, causing application downtime, data access failures, and requiring manual administrator intervention to resume operations.

How an attack unfolds

An attacker or misconfigured process triggers the backlog_store() error path on an array lacking write-mostly devices; the missing resume leaves the array suspended indefinitely, blocking all I/O.

How to fix it

Apply the upstream kernel patch that replaces the error-path unlock with mddev_unlock_and_resume() and reboot or reload the md subsystem.

How to confirm the fix worked

Inspect the md/bitmap.c source for the corrected backlog_store() error handling that calls mddev_unlock_and_resume(); verify array resumes correctly after triggering the same error condition.

Typical attack path

  1. Identify or configure an md array without write-mostly devices
  2. Invoke backlog_store() to enter the error path
  3. Observe failure to call mddev_unlock_and_resume()
  4. Array remains suspended and blocks subsequent I/O

How to detect it

Review kernel logs (dmesg, /var/log/kern.log) for md array suspension messages without a matching resume; correlate with processes calling bitmap configuration interfaces.

What your security team should do

  • Prioritize kernel updates containing the md/bitmap fix on all systems using software RAID
  • Audit md array configurations for write-mostly device usage
  • Monitor kernel logs for unexpected array suspension events

The record

In the Linux kernel, the following vulnerability has been resolved: md/bitmap: resume array on backlog_store() error path backlog_store() suspends the array before checking whether a write-mostly device exists. If no such device exists, the error path only unlocks reconfig_mutex and leaves the array suspended, blocking subsequent I/O. Use mddev_unlock_and_resume() to release both states.

Affected packages

Ecosystem Package Introduced Fixed