# CVE-2025-68341: veth: reduce XDP no_direct return section to fix race

> A race condition in the Linux kernel veth driver involving XDP return frames can lead to undefined behavior or potential memory corruption issues.

- **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:** 23 Dec 2025
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2025-68341, DEBIAN-CVE-2025-68341, GHSA-68w5-72rc-pgrc, UBUNTU-CVE-2025-68341

## What is CVE-2025-68341?

CVE-2025-68341 is a critical vulnerability in Linux, published on 23 Dec 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:

veth: reduce XDP no_direct return section to fix race

As explain in commit fa349e396e48 ("veth: Fix race with AF_XDP exposing
old or uninitialized descriptors") for veth there is a chance after
napi_complete_done() that another CPU can manage start another NAPI
instance running veth_pool(). For NAPI this is correctly handled as the
napi_schedule_prep() check will prevent multiple instances from getting
scheduled, but for the remaining code in veth_pool() this can run
concurrent with the newly started NAPI instance.

The problem/race is that xdp_clear_return_frame_no_direct() isn't
designed to be nested.

Prior to commit 401cb7dae813 ("net: Reference bpf_redirect_info via
task_struct on PREEMPT_RT.") the temporary BPF net context
bpf_redirect_info was stored per CPU, where this wasn't an issue. Since
this commit the BPF context is stored in 'current' task_struct. When
running veth in threaded-NAPI mode, then the kthread becomes the storage
area. Now a race exists between two concurrent veth_pool() function calls
one exiting NAPI and one running new NAPI, both using the same BPF net
context.

Race is when another CPU gets within the xdp_set_return_frame_no_direct()
section before exiting veth_pool() calls the clear-function
xdp_clear_return_frame_no_direct().

## Which versions are affected by CVE-2025-68341?


## How do I fix CVE-2025-68341?

Apply the vendor's patch.

## Is CVE-2025-68341 being exploited?

There is no known exploitation of CVE-2025-68341 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68341 and fix it if it is affected.

What it is: CVE-2025-68341 is a critical vulnerability in Linux, published on 23 Dec 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-2025-68341 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-2025-68341/ (Markdown: https://insights.sbomify.com/CVE-2025-68341/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68341
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68341
- OSV: https://osv.dev/vulnerability/CVE-2025-68341

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68341/
Summaries are generated and may contain mistakes; the official description above is the record.