# CVE-2026-53244: VFS: fix possible failure to unlock in nfsd4_create_file()

> A logic error in the Linux kernel NFS server can cause a deadlock if atomic_create fails, leading to denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 25 Jun 2026
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-53244, GHSA-q9qr-5342-rrw2, UBUNTU-CVE-2026-53244

## What is CVE-2026-53244?

CVE-2026-53244 is a high-severity denial of service vulnerability in Linux kernel, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

VFS: fix possible failure to unlock in nfsd4_create_file()

atomic_create() in fs/namei.c drops the reference to the dentry
when it returns an error.
This behaviour was imported into dentry_create() so that it
will drop the reference if an error is returned from atomic_create(),
though not if vfs_create() returns an error (in the case where
->atomic_create is not supported).

The caller - nfsd4_create_file() - is made aware of this by checking
path->dentry, which will either be a counted reference to a dentry, or
an error pointer.

However the change to use start_creating()/end_creating() (which landed
shortly before the dentry_create() change landed, though was likely
developed around the same time) means that nfsd4_create_file() *needs* a
valid dentry so that it can unlock the parent.

The net result is that if NFSD exports a filesystem which uses
->atomic_create, and if a call to ->atomic_create returns an error, then
nfsd4_create_file() will pass an error pointer to end_creating()
and the parent will not be unlocked.

Fix this by changing dentry_create() to make sure path->dentry is always
a valid dentry, never an error-pointer.  The actual error is already
returned a different way.

Note that if ->atomic_create() returns a different dentry (which may not
be possible in practice) we are guaranteed (because it is only ever
provided by d_spliace_alias()) that it will have the same d_parent and
so it will have the same effect when passed to end_creating().

## Which versions are affected by CVE-2026-53244?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-53244?

Apply the vendor's patch.

## Is CVE-2026-53244 being exploited?

There is no known exploitation of CVE-2026-53244 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53244 and fix it if it is affected.

What it is: CVE-2026-53244 is a high-severity denial of service vulnerability in Linux kernel, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53244 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53244/ (Markdown: https://insights.sbomify.com/CVE-2026-53244/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53244
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53244
- OSV: https://osv.dev/vulnerability/CVE-2026-53244

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53244/
Summaries are generated and may contain mistakes; the official description above is the record.