# CVE-2025-37787: net: dsa: mv88e6xxx: avoid unregistering devlink regions which were never registered

> A NULL pointer dereference in the mv88e6xxx network driver causes a kernel crash when unbinding the driver on chips lacking specific devlink regions.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 May 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-37787, DEBIAN-CVE-2025-37787, GHSA-hfj5-q228-92r2, ROOT-OS-DEBIAN-12-CVE-2025-37787, ROOT-OS-UBUNTU-2204-CVE-2025-37787, ROOT-OS-UBUNTU-2404-CVE-2025-37787, UBUNTU-CVE-2025-37787

## What is CVE-2025-37787?

CVE-2025-37787 is a medium-severity vulnerability in Linux kernel, published on 1 May 2025. 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:

net: dsa: mv88e6xxx: avoid unregistering devlink regions which were never registered

Russell King reports that a system with mv88e6xxx dereferences a NULL
pointer when unbinding this driver:
https://lore.kernel.org/netdev/Z_lRkMlTJ1KQ0kVX@shell.armlinux.org.uk/

The crash seems to be in devlink_region_destroy(), which is not NULL
tolerant but is given a NULL devlink global region pointer.

At least on some chips, some devlink regions are conditionally registered
since the blamed commit, see mv88e6xxx_setup_devlink_regions_global():

		if (cond && !cond(chip))
			continue;

These are MV88E6XXX_REGION_STU and MV88E6XXX_REGION_PVT. If the chip
does not have an STU or PVT, it should crash like this.

To fix the issue, avoid unregistering those regions which are NULL, i.e.
were skipped at mv88e6xxx_setup_devlink_regions_global() time.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-37787?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-37787?

Apply the vendor's patch.

## Is CVE-2025-37787 being exploited?

There is no known exploitation of CVE-2025-37787 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-2025-37787 and fix it if it is affected.

What it is: CVE-2025-37787 is a medium-severity vulnerability in Linux kernel, published on 1 May 2025. 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-2025-37787 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-2025-37787/ (Markdown: https://insights.sbomify.com/CVE-2025-37787/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37787
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37787
- OSV: https://osv.dev/vulnerability/CVE-2025-37787

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37787/
Summaries are generated and may contain mistakes; the official description above is the record.