# CVE-2024-44950: serial: sc16is7xx: fix invalid FIFO access with special register set

> A race condition in the sc16is7xx serial driver causes invalid FIFO access, potentially leading to system instability or denial of service.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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:** 4 Sep 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-50204, AZL-50239, BELL-CVE-2024-44950, DEBIAN-CVE-2024-44950, GHSA-hw6f-2v4x-m477, ROOT-OS-DEBIAN-11-CVE-2024-44950, ROOT-OS-UBUNTU-2204-CVE-2024-44950, UBUNTU-CVE-2024-44950

## What is CVE-2024-44950?

CVE-2024-44950 is a high-severity vulnerability in Linux kernel, published on 4 Sep 2024. 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: sc16is7xx: fix invalid FIFO access with special register set

When enabling access to the special register set, Receiver time-out and
RHR interrupts can happen. In this case, the IRQ handler will try to read
from the FIFO thru the RHR register at address 0x00, but address 0x00 is
mapped to DLL register, resulting in erroneous FIFO reading.

Call graph example:
    sc16is7xx_startup(): entry
    sc16is7xx_ms_proc(): entry
    sc16is7xx_set_termios(): entry
    sc16is7xx_set_baud(): DLH/DLL = $009C --> access special register set
    sc16is7xx_port_irq() entry            --> IIR is 0x0C
    sc16is7xx_handle_rx() entry
    sc16is7xx_fifo_read(): --> unable to access FIFO (RHR) because it is
                               mapped to DLL (LCR=LCR_CONF_MODE_A)
    sc16is7xx_set_baud(): exit --> Restore access to general register set

Fix the problem by claiming the efr_lock mutex when accessing the Special
register set.

## Which versions are affected by CVE-2024-44950?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-44950?

Apply the vendor's patch.

## Is CVE-2024-44950 being exploited?

There is no known exploitation of CVE-2024-44950 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-2024-44950 and fix it if it is affected.

What it is: CVE-2024-44950 is a high-severity vulnerability in Linux kernel, published on 4 Sep 2024. 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-2024-44950 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-2024-44950/ (Markdown: https://insights.sbomify.com/CVE-2024-44950/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-44950
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-44950
- OSV: https://osv.dev/vulnerability/CVE-2024-44950

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-44950/
Summaries are generated and may contain mistakes; the official description above is the record.