# CVE-2026-93073: dax: read holder_ops once in dax_holder_notify_failure()

> A race condition in the Linux kernel DAX subsystem can cause a null pointer dereference, leading to a system crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-102710, BELL-CVE-2026-93073, DEBIAN-CVE-2026-93073, GHSA-xxf3-2jmr-5rfc, UBUNTU-CVE-2026-93073

## What is CVE-2026-93073?

CVE-2026-93073 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

dax: read holder_ops once in dax_holder_notify_failure()

dax_holder_notify_failure() reads dax_dev->holder_ops twice without
READ_ONCE() -- once for the NULL check and once for the indirect
notify_failure() call. A concurrent fs_put_dax() can clear holder_ops
between the two reads, so the check can observe a non-NULL pointer while
the call dereferences NULL. (kill_dax() also clears holder_ops, but only
after synchronize_srcu(), so it cannot race a reader that is inside
dax_read_lock(); fs_put_dax() does no such synchronization.)

Fetch holder_ops once into a local with READ_ONCE() so the NULL check and
the indirect call observe the same value.

## Which versions are affected by CVE-2026-93073?


## How do I fix CVE-2026-93073?

Apply the vendor's patch.

## Is CVE-2026-93073 being exploited?

There is no known exploitation of CVE-2026-93073 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93073 and fix it if it is affected.

What it is: CVE-2026-93073 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-93073 in the wild and no public exploit code.

Affected product: Linux. 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-2026-93073/ (Markdown: https://insights.sbomify.com/CVE-2026-93073/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93073
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93073
- OSV: https://osv.dev/vulnerability/CVE-2026-93073

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93073/
Summaries are generated and may contain mistakes; the official description above is the record.