# CVE-2022-50569: xfrm: Update ipcomp_scratches with NULL when freed

> A use-after-free or invalid memory access in the Linux kernel's IPComp module can cause a system crash when memory allocation fails.

- **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:** 22 Oct 2025
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-50569, GHSA-h9qx-33jg-gh24, UBUNTU-CVE-2022-50569

## What is CVE-2022-50569?

CVE-2022-50569 is a high-severity vulnerability in Linux, published on 22 Oct 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:

xfrm: Update ipcomp_scratches with NULL when freed

Currently if ipcomp_alloc_scratches() fails to allocate memory
ipcomp_scratches holds obsolete address. So when we try to free the
percpu scratches using ipcomp_free_scratches() it tries to vfree non
existent vm area. Described below:

static void * __percpu *ipcomp_alloc_scratches(void)
{
        ...
        scratches = alloc_percpu(void *);
        if (!scratches)
                return NULL;
ipcomp_scratches does not know about this allocation failure.
Therefore holding the old obsolete address.
        ...
}

So when we free,

static void ipcomp_free_scratches(void)
{
        ...
        scratches = ipcomp_scratches;
Assigning obsolete address from ipcomp_scratches

        if (!scratches)
                return;

        for_each_possible_cpu(i)
               vfree(*per_cpu_ptr(scratches, i));
Trying to free non existent page, causing warning: trying to vfree
existent vm area.
        ...
}

Fix this breakage by updating ipcomp_scrtches with NULL when scratches
is freed

## Which versions are affected by CVE-2022-50569?


## How do I fix CVE-2022-50569?

Apply the vendor's patch.

## Is CVE-2022-50569 being exploited?

There is no known exploitation of CVE-2022-50569 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-50569 and fix it if it is affected.

What it is: CVE-2022-50569 is a high-severity vulnerability in Linux, published on 22 Oct 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-2022-50569 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-2022-50569/ (Markdown: https://insights.sbomify.com/CVE-2022-50569/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50569
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50569
- OSV: https://osv.dev/vulnerability/CVE-2022-50569

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50569/
Summaries are generated and may contain mistakes; the official description above is the record.