# CVE-2022-49418: NFSv4: Fix free of uninitialized nfs4_label on referral lookup.

> A use-after-free vulnerability in the Linux kernel NFSv4 module allows local attackers to cause a system crash via referral lookup.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 26 Feb 2025
- **Updated:** 5 Aug 2026
- **Also known as:** DEBIAN-CVE-2022-49418, GHSA-cmjx-92rg-pwqx, UBUNTU-CVE-2022-49418

## What is CVE-2022-49418?

CVE-2022-49418 is a critical use after free vulnerability in Linux kernel, published on 26 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

NFSv4: Fix free of uninitialized nfs4_label on referral lookup.

Send along the already-allocated fattr along with nfs4_fs_locations, and
drop the memcpy of fattr.  We end up growing two more allocations, but this
fixes up a crash as:

PID: 790    TASK: ffff88811b43c000  CPU: 0   COMMAND: "ls"
 #0 [ffffc90000857920] panic at ffffffff81b9bfde
 #1 [ffffc900008579c0] do_trap at ffffffff81023a9b
 #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78
 #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45
 #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de
 #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]
 #6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f
 #7 [ffffc90000857c60] walk_component at ffffffff813a86c4
 #8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553
 #9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b

Weakness: CWE-908 (Use of Uninitialized Resource)

## Which versions are affected by CVE-2022-49418?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2022-49418?

Apply the vendor's patch.

## Is CVE-2022-49418 being exploited?

There is no known exploitation of CVE-2022-49418 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-2022-49418 and fix it if it is affected.

What it is: CVE-2022-49418 is a critical use after free vulnerability in Linux kernel, published on 26 Feb 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-49418 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-2022-49418/ (Markdown: https://insights.sbomify.com/CVE-2022-49418/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-49418
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-49418
- OSV: https://osv.dev/vulnerability/CVE-2022-49418

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-49418/
Summaries are generated and may contain mistakes; the official description above is the record.