# CVE-2023-54220: serial: 8250: Fix oops for port->pm on uart_change_pm()

> A null pointer dereference in the Linux kernel 8250 serial driver causes a system crash when unloading specific hardware drivers.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 30 Dec 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2023-54220, DEBIAN-CVE-2023-54220, GHSA-ghxp-vq7f-3f7c, UBUNTU-CVE-2023-54220

## What is CVE-2023-54220?

CVE-2023-54220 is a high-severity vulnerability in Linux, published on 30 Dec 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:

serial: 8250: Fix oops for port->pm on uart_change_pm()

Unloading a hardware specific 8250 driver can produce error "Unable to
handle kernel paging request at virtual address" about ten seconds after
unloading the driver. This happens on uart_hangup() calling
uart_change_pm().

Turns out commit 04e82793f068 ("serial: 8250: Reinit port->pm on port
specific driver unbind") was only a partial fix. If the hardware specific
driver has initialized port->pm function, we need to clear port->pm too.
Just reinitializing port->ops does not do this. Otherwise serial8250_pm()
will call port->pm() instead of serial8250_do_pm().

## Which versions are affected by CVE-2023-54220?


## How do I fix CVE-2023-54220?

Apply the vendor's patch.

## Is CVE-2023-54220 being exploited?

There is no known exploitation of CVE-2023-54220 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-54220 and fix it if it is affected.

What it is: CVE-2023-54220 is a high-severity vulnerability in Linux, published on 30 Dec 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-2023-54220 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-2023-54220/ (Markdown: https://insights.sbomify.com/CVE-2023-54220/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-54220
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-54220
- OSV: https://osv.dev/vulnerability/CVE-2023-54220

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-54220/
Summaries are generated and may contain mistakes; the official description above is the record.