Cloudanix VulnDB

CVE-2026-90396

None

CVSS

—

EPSS

0.2%

Published

Sep 17, 2026

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A bug in how Linux handles certain disk operations could let attackers slowly drain memory or cause crashes on affected computers.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Memory Corruption
Remediation
Patch
Effort
Medium
Patch risk
Low

What it actually does

A failed integrity mapping in the block layer holds a direct I/O (DIO) reference without releasing it, causing a reference leak that bypasses normal bio completion paths and can lead to memory corruption or resource exhaustion.

Why it matters to the business

Linux systems performing block I/O operations may experience instability, memory leaks, or crashes, potentially disrupting services and requiring unplanned restarts or maintenance.

How an attack unfolds

An attacker crafts I/O sequences that trigger metadata mapping errors during integrity checks; the unhandled reference leak accumulates across multiple bio submissions, eventually corrupting kernel memory structures or exhausting resources.

How to fix it

Update the Linux kernel to a version containing the fix for the DIO reference leak on metadata mapping errors; apply the patch that ensures full bio completion paths are followed on integrity failures.

How to confirm the fix worked

Confirm the kernel source contains the commit resolving the DIO leak, verify that integrity mapping error paths now invoke complete bio ending logic, and test with workloads that previously triggered mapping failures.

Typical attack path

  1. Identify a target system performing direct I/O with integrity metadata enabled
  2. Trigger repeated metadata mapping failures in the block layer
  3. Allow leaked DIO references to accumulate without triggering full bio completion
  4. Exploit resulting memory state for corruption or denial of service

How to detect it

Examine kernel logs for repeated integrity mapping errors followed by resource warnings; look for abnormal growth in DIO structures or bio allocations without corresponding completions in memory profiling tools.

What your security team should do

  • Prioritize kernel updates on systems handling high volumes of direct or integrity-protected I/O
  • Monitor for memory pressure or unexpected OOM events on block devices
  • Review change logs for the specific block-layer DIO fix before deployment

The record

In the Linux kernel, the following vulnerability has been resolved: block: fix dio leak on metadata mapping error A failed integrity mapping holds a dio reference, so we need to go through the full bio ending in case there were previously submitted bio's in the sequence.

Affected packages

Ecosystem Package Introduced Fixed