# CVE-2025-37838: HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition

> A race condition in the Linux kernel HSI ssi_protocol driver allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.

- **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:** 18 Apr 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-37838, DEBIAN-CVE-2025-37838, GHSA-m8p9-q552-5h79, ROOT-OS-UBUNTU-2204-CVE-2025-37838, ROOT-OS-UBUNTU-2404-CVE-2025-37838, UBUNTU-CVE-2025-37838

## What is CVE-2025-37838?

CVE-2025-37838 is a high-severity use after free vulnerability in Linux kernel, published on 18 Apr 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:

HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition

In the ssi_protocol_probe() function, &ssi->work is bound with
ssip_xmit_work(), In ssip_pn_setup(), the ssip_pn_xmit() function
within the ssip_pn_ops structure is capable of starting the
work.

If we remove the module which will call ssi_protocol_remove()
to make a cleanup, it will free ssi through kfree(ssi),
while the work mentioned above will be used. The sequence
of operations that may lead to a UAF bug is as follows:

CPU0                                    CPU1

                        | ssip_xmit_work
ssi_protocol_remove     |
kfree(ssi);             |
                        | struct hsi_client *cl = ssi->cl;
                        | // use ssi

Fix it by ensuring that the work is canceled before proceeding
with the cleanup in ssi_protocol_remove().

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-37838?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-37838?

Apply the vendor's patch.

## Is CVE-2025-37838 being exploited?

There is no known exploitation of CVE-2025-37838 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-2025-37838 and fix it if it is affected.

What it is: CVE-2025-37838 is a high-severity use after free vulnerability in Linux kernel, published on 18 Apr 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-2025-37838 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-2025-37838/ (Markdown: https://insights.sbomify.com/CVE-2025-37838/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-37838
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-37838
- OSV: https://osv.dev/vulnerability/CVE-2025-37838

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-37838/
Summaries are generated and may contain mistakes; the official description above is the record.