# CVE-2024-44951: serial: sc16is7xx: fix TX fifo corruption

> A race condition in the sc16is7xx serial driver allows received data to corrupt transmit buffers, potentially altering outgoing data.

- **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:** 4 Sep 2024
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-50225, BELL-CVE-2024-44951, DEBIAN-CVE-2024-44951, GHSA-qx5p-7g35-jj49, ROOT-OS-DEBIAN-12-CVE-2024-44951, ROOT-OS-UBUNTU-2404-CVE-2024-44951, UBUNTU-CVE-2024-44951

## What is CVE-2024-44951?

CVE-2024-44951 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 TX fifo corruption

Sometimes, when a packet is received on channel A at almost the same time
as a packet is about to be transmitted on channel B, we observe with a
logic analyzer that the received packet on channel A is transmitted on
channel B. In other words, the Tx buffer data on channel B is corrupted
with data from channel A.

The problem appeared since commit 4409df5866b7 ("serial: sc16is7xx: change
EFR lock to operate on each channels"), which changed the EFR locking to
operate on each channel instead of chip-wise.

This commit has introduced a regression, because the EFR lock is used not
only to protect the EFR registers access, but also, in a very obscure and
undocumented way, to protect access to the data buffer, which is shared by
the Tx and Rx handlers, but also by each channel of the IC.

Fix this regression first by switching to kfifo_out_linear_ptr() in
sc16is7xx_handle_tx() to eliminate the need for a shared Rx/Tx buffer.

Secondly, replace the chip-wise Rx buffer with a separate Rx buffer for
each channel.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2024-44951?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-44951?

Apply the vendor's patch.

## Is CVE-2024-44951 being exploited?

There is no known exploitation of CVE-2024-44951 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-2024-44951 and fix it if it is affected.

What it is: CVE-2024-44951 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-2024-44951 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-2024-44951/ (Markdown: https://insights.sbomify.com/CVE-2024-44951/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-44951
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-44951
- OSV: https://osv.dev/vulnerability/CVE-2024-44951

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-44951/
Summaries are generated and may contain mistakes; the official description above is the record.