# CVE-2026-93075: dax/fsdev: clear pgmap ops and owner on unbind

> A use-after-free vulnerability in the Linux kernel DAX fsdev driver allows local attackers to execute arbitrary code or cause a denial of service via stale pointers after device unbind.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **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:** DEBIAN-CVE-2026-93075, GHSA-m6jw-vjqw-78fh, UBUNTU-CVE-2026-93075

## What is CVE-2026-93075?

CVE-2026-93075 is an use after free 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/fsdev: clear pgmap ops and owner on unbind

fsdev_dax_probe() sets pgmap->ops = &fsdev_pagemap_ops and
pgmap->owner = dev_dax, but nothing ever clears them. For a dynamic
device the pgmap is devm-allocated and freed on unbind, so this is
harmless. For a static device the pgmap is the shared, long-lived one
owned by the dax bus (kill_dev_dax() only NULLs dev_dax->pgmap for the
non-static case), and device.c's probe sets only pgmap->type, never
clearing ops/owner.

So after fsdev unbinds a static device the stale fsdev_pagemap_ops
survives on the shared pgmap. If the device is then rebound to
device_dax (MEMORY_DEVICE_GENERIC, which installs no ->memory_failure),
or the fsdev_dax module is unloaded, a subsequent memory_failure on that
pgmap dispatches through the stale -- and possibly freed -- handler.

Register a devm action that clears pgmap->ops and pgmap->owner on unbind,
symmetric with setting them at probe, so the pgmap carries no fsdev state
once fsdev is detached.

## Which versions are affected by CVE-2026-93075?


## How do I fix CVE-2026-93075?

Apply the vendor's patch.

## Is CVE-2026-93075 being exploited?

There is no known exploitation of CVE-2026-93075 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93075 and fix it if it is affected.

What it is: CVE-2026-93075 is an use after free 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-2026-93075 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-2026-93075/ (Markdown: https://insights.sbomify.com/CVE-2026-93075/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93075
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93075
- OSV: https://osv.dev/vulnerability/CVE-2026-93075

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93075/
Summaries are generated and may contain mistakes; the official description above is the record.