# CVE-2022-50425: x86/fpu: Fix copy_xstate_to_uabi() to copy init states correctly

> A local attacker can trigger a kernel NULL pointer dereference in the x86 FPU code, causing a system crash and denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 1 Oct 2025
- **Updated:** 11 May 2026
- **Also known as:** DEBIAN-CVE-2022-50425, GHSA-cfcx-rgr2-rqqq, ROOT-OS-UBUNTU-2204-CVE-2022-50425, UBUNTU-CVE-2022-50425

## What is CVE-2022-50425?

CVE-2022-50425 is a medium-severity vulnerability in Linux kernel, published on 1 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:

x86/fpu: Fix copy_xstate_to_uabi() to copy init states correctly

When an extended state component is not present in fpstate, but in init
state, the function copies from init_fpstate via copy_feature().

But, dynamic states are not present in init_fpstate because of all-zeros
init states. Then retrieving them from init_fpstate will explode like this:

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 ...
 RIP: 0010:memcpy_erms+0x6/0x10
  ? __copy_xstate_to_uabi_buf+0x381/0x870
  fpu_copy_guest_fpstate_to_uabi+0x28/0x80
  kvm_arch_vcpu_ioctl+0x14c/0x1460 [kvm]
  ? __this_cpu_preempt_check+0x13/0x20
  ? vmx_vcpu_put+0x2e/0x260 [kvm_intel]
  kvm_vcpu_ioctl+0xea/0x6b0 [kvm]
  ? kvm_vcpu_ioctl+0xea/0x6b0 [kvm]
  ? __fget_light+0xd4/0x130
  __x64_sys_ioctl+0xe3/0x910
  ? debug_smp_processor_id+0x17/0x20
  ? fpregs_assert_state_consistent+0x27/0x50
  do_syscall_64+0x3f/0x90
  entry_SYSCALL_64_after_hwframe+0x63/0xcd

Adjust the 'mask' to zero out the userspace buffer for the features that
are not available both from fpstate and from init_fpstate.

The dynamic features depend on the compacted XSAVE format. Ensure it is
enabled before reading XCOMP_BV in init_fpstate.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2022-50425?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-50425?

Apply the vendor's patch.

## Is CVE-2022-50425 being exploited?

There is no known exploitation of CVE-2022-50425 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-2022-50425 and fix it if it is affected.

What it is: CVE-2022-50425 is a medium-severity vulnerability in Linux kernel, published on 1 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-2022-50425 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-2022-50425/ (Markdown: https://insights.sbomify.com/CVE-2022-50425/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-50425
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-50425
- OSV: https://osv.dev/vulnerability/CVE-2022-50425

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-50425/
Summaries are generated and may contain mistakes; the official description above is the record.