---
id: CVE-2025-68368
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  md: init bioset in mddev_init

  IO operations may be needed before md_run(), such as updating metadata
  after writing sysfs
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  md: init bioset in mddev_init

  IO operations may be needed before md_run(), such as updating metadata
  after writing sysfs. Without bioset, this triggers a NULL pointer
  …
severity: none
published: '2025-12-24'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T11:10:00.203'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-68368'
references:
  - url: 'https://git.kernel.org/stable/c/381a3ce1c0ffed647c9b913e142b099c7e9d5afc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9d37fe37dfa0833a8768740f0575e0ffd793cb4a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00174
epssPercentile: 0.06312
ingestedAt: '2026-10-13T11:23:51.153Z'
---

## Overview

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

md: init bioset in mddev_init

IO operations may be needed before md_run(), such as updating metadata
after writing sysfs. Without bioset, this triggers a NULL pointer
dereference as below:

 BUG: kernel NULL pointer dereference, address: 0000000000000020
 Call Trace:
  md_update_sb+0x658/0xe00
  new_level_store+0xc5/0x120
  md_attr_store+0xc9/0x1e0
  sysfs_kf_write+0x6f/0xa0
  kernfs_fop_write_iter+0x141/0x2a0
  vfs_write+0x1fc/0x5a0
  ksys_write+0x79/0x180
  __x64_sys_write+0x1d/0x30
  x64_sys_call+0x2818/0x2880
  do_syscall_64+0xa9/0x580
  entry_SYSCALL_64_after_hwframe+0x4b/0x53

Reproducer
```
  mdadm -CR /dev/md0 -l1 -n2 /dev/sd[cd]
  echo inactive > /sys/block/md0/md/array_state
  echo 10 > /sys/block/md0/md/new_level
```

mddev_init() can only be called once per mddev, no need to test if bioset
has been initialized anymore.

## Remediation

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