# CVE-2024-50222: iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP

> A local attacker can cause a system hang and warning in the Linux kernel when specific highmem debug configurations are enabled.

- **Severity:** High 7.0 (`CVSS:3.1/AV:L/AC:H/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:** 9 Nov 2024
- **Updated:** 5 Aug 2026
- **Also known as:** AZL-53156, BELL-CVE-2024-50222, DEBIAN-CVE-2024-50222, GHSA-78hj-7cr6-hq8q, UBUNTU-CVE-2024-50222

## What is CVE-2024-50222?

CVE-2024-50222 is a high-severity denial of service vulnerability in Linux kernel, published on 9 Nov 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:

iov_iter: fix copy_page_from_iter_atomic() if KMAP_LOCAL_FORCE_MAP

generic/077 on x86_32 CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP=y with highmem,
on huge=always tmpfs, issues a warning and then hangs (interruptibly):

WARNING: CPU: 5 PID: 3517 at mm/highmem.c:622 kunmap_local_indexed+0x62/0xc9
CPU: 5 UID: 0 PID: 3517 Comm: cp Not tainted 6.12.0-rc4 #2
...
copy_page_from_iter_atomic+0xa6/0x5ec
generic_perform_write+0xf6/0x1b4
shmem_file_write_iter+0x54/0x67

Fix copy_page_from_iter_atomic() by limiting it in that case
(include/linux/skbuff.h skb_frag_must_loop() does similar).

But going forward, perhaps CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is too
surprising, has outlived its usefulness, and should just be removed?

## Which versions are affected by CVE-2024-50222?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-50222?

Apply the vendor's patch.

## Is CVE-2024-50222 being exploited?

There is no known exploitation of CVE-2024-50222 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-2024-50222 and fix it if it is affected.

What it is: CVE-2024-50222 is a high-severity denial of service vulnerability in Linux kernel, published on 9 Nov 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-2024-50222 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-2024-50222/ (Markdown: https://insights.sbomify.com/CVE-2024-50222/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-50222
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-50222
- OSV: https://osv.dev/vulnerability/CVE-2024-50222

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-50222/
Summaries are generated and may contain mistakes; the official description above is the record.