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VulnerabilityPublished Updated

CVE-2025-22070: Linux kernel · fs/9p: fix NULL pointer dereference on mkdir

Affects Linux kernelSource GCVE Database

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Not known to be exploited · CVSS 5.5 Medium.

Data as of 30 Oct 2026, 14:06 UTC

CVSS 3.1 base score
5.5Medium
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CISA-ADPCVSS 3.15.5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 16 Apr 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

AI-suggested

A fix is available that corrects the function call order in the Linux kernel source code. Users should apply the official Linux kernel patch that swaps the calls in v9fs_vfs_mkdir_dotl() to prevent the NULL pointer dereference. No other mitigation or workaround is indicated.

Description

CVE-2025-22070 is a vulnerability in the Linux kernel's 9p filesystem client that causes a NULL pointer dereference when creating a subdirectory with the 'posixacl' mount option and default ACLs set on the parent directory. This results in a kernel crash (denial of service). The issue is due to an incorrect sequence of function calls in the mkdir operation, where a pointer is set to NULL before it is used. The fix involves swapping the order of these calls to prevent the NULL pointer dereference.

References

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