# CVE-2024-35801: x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD

> A kernel crash occurs due to state desynchronization in x86 FPU handling, leading to a denial of service.

- **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:** 17 May 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2024-35801, DEBIAN-CVE-2024-35801, GHSA-r4ww-r2x2-fj39, ROOT-OS-UBUNTU-2204-CVE-2024-35801, UBUNTU-CVE-2024-35801

## What is CVE-2024-35801?

CVE-2024-35801 is a high-severity vulnerability in Linux kernel, published on 17 May 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:

x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD

Commit 672365477ae8 ("x86/fpu: Update XFD state where required") and
commit 8bf26758ca96 ("x86/fpu: Add XFD state to fpstate") introduced a
per CPU variable xfd_state to keep the MSR_IA32_XFD value cached, in
order to avoid unnecessary writes to the MSR.

On CPU hotplug MSR_IA32_XFD is reset to the init_fpstate.xfd, which
wipes out any stale state. But the per CPU cached xfd value is not
reset, which brings them out of sync.

As a consequence a subsequent xfd_update_state() might fail to update
the MSR which in turn can result in XRSTOR raising a #NM in kernel
space, which crashes the kernel.

To fix this, introduce xfd_set_state() to write xfd_state together
with MSR_IA32_XFD, and use it in all places that set MSR_IA32_XFD.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-35801?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-35801?

Apply the vendor's patch.

## Is CVE-2024-35801 being exploited?

There is no known exploitation of CVE-2024-35801 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-2024-35801 and fix it if it is affected.

What it is: CVE-2024-35801 is a high-severity vulnerability in Linux kernel, published on 17 May 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-2024-35801 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-2024-35801/ (Markdown: https://insights.sbomify.com/CVE-2024-35801/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-35801
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-35801
- OSV: https://osv.dev/vulnerability/CVE-2024-35801

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-35801/
Summaries are generated and may contain mistakes; the official description above is the record.