# CVE-2023-53176: serial: 8250: Reinit port->pm on port specific driver unbind

> A use-after-free in the Linux kernel serial driver causes a system crash when unbinding specific hardware drivers, leading to denial of service.

- **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:** 15 Sep 2025
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2023-53176, DEBIAN-CVE-2023-53176, GHSA-j67r-mf5q-82pc, UBUNTU-CVE-2023-53176

## What is CVE-2023-53176?

CVE-2023-53176 is a high-severity use after free vulnerability in Linux kernel, published on 15 Sep 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: Reinit port->pm on port specific driver unbind

When we unbind a serial port hardware specific 8250 driver, the generic
serial8250 driver takes over the port. After that we see an oops about 10
seconds later. This can produce the following at least on some TI SoCs:

Unhandled fault: imprecise external abort (0x1406)
Internal error: : 1406 [#1] SMP ARM

Turns out that we may still have the serial port hardware specific driver
port->pm in use, and serial8250_pm() tries to call it after the port
specific driver is gone:

serial8250_pm [8250_base] from uart_change_pm+0x54/0x8c [serial_base]
uart_change_pm [serial_base] from uart_hangup+0x154/0x198 [serial_base]
uart_hangup [serial_base] from __tty_hangup.part.0+0x328/0x37c
__tty_hangup.part.0 from disassociate_ctty+0x154/0x20c
disassociate_ctty from do_exit+0x744/0xaac
do_exit from do_group_exit+0x40/0x8c
do_group_exit from __wake_up_parent+0x0/0x1c

Let's fix the issue by calling serial8250_set_defaults() in
serial8250_unregister_port(). This will set the port back to using
the serial8250 default functions, and sets the port->pm to point to
serial8250_pm.

## Which versions are affected by CVE-2023-53176?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2023-53176?

Apply the vendor's patch.

## Is CVE-2023-53176 being exploited?

There is no known exploitation of CVE-2023-53176 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-2023-53176 and fix it if it is affected.

What it is: CVE-2023-53176 is a high-severity use after free vulnerability in Linux kernel, published on 15 Sep 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-2023-53176 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-2023-53176/ (Markdown: https://insights.sbomify.com/CVE-2023-53176/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53176
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53176
- OSV: https://osv.dev/vulnerability/CVE-2023-53176

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53176/
Summaries are generated and may contain mistakes; the official description above is the record.