CVE-2025-22070: Linux kernel · fs/9p: fix NULL pointer dereference on mkdir
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 30 Oct 2026, 14:06 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 5.5 |
|---|
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Apr 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
- git.kernel.org/stable/c/d5031a71a2d0e76d3eb02b52b21c17c881919d53 (opens in a new tab)
- git.kernel.org/stable/c/b17edabd917142d9ecd058f7c6ee9da5e32af1dd (opens in a new tab)
- git.kernel.org/stable/c/8522051c58d68146b93e8a5ba9987e83b3d64e7b (opens in a new tab)
- git.kernel.org/stable/c/2139dea5c53e3bb63ac49a6901c85e525a80ee8a (opens in a new tab)
- git.kernel.org/stable/c/6517b395cb1e43fbf3962dd93e6fb4a5e5ab100e (opens in a new tab)
- git.kernel.org/stable/c/3f61ac7c65bdb26accb52f9db66313597e759821 (opens in a new tab)