# CVE-2025-68245: net: netpoll: fix incorrect refcount handling causing incorrect cleanup

> A refcount handling error in the Linux kernel netpoll subsystem causes memory leaks and improper cleanup, potentially leading to denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Dec 2025
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-68245, DEBIAN-CVE-2025-68245, GHSA-jr3x-g84v-9793, ROOT-OS-DEBIAN-12-CVE-2025-68245, ROOT-OS-DEBIAN-13-CVE-2025-68245, ROOT-OS-UBUNTU-2204-CVE-2025-68245, ROOT-OS-UBUNTU-2404-CVE-2025-68245, UBUNTU-CVE-2025-68245

## What is CVE-2025-68245?

CVE-2025-68245 is an use after free vulnerability in Linux, published on 16 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:

net: netpoll: fix incorrect refcount handling causing incorrect cleanup

commit efa95b01da18 ("netpoll: fix use after free") incorrectly
ignored the refcount and prematurely set dev->npinfo to NULL during
netpoll cleanup, leading to improper behavior and memory leaks.

Scenario causing lack of proper cleanup:

1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is
   allocated, and refcnt = 1
   - Keep in mind that npinfo is shared among all netpoll instances. In
     this case, there is just one.

2) Another netpoll is also associated with the same NIC and
   npinfo->refcnt += 1.
   - Now dev->npinfo->refcnt = 2;
   - There is just one npinfo associated to the netdev.

3) When the first netpolls goes to clean up:
   - The first cleanup succeeds and clears np->dev->npinfo, ignoring
     refcnt.
     - It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);`
   - Set dev->npinfo = NULL, without proper cleanup
   - No ->ndo_netpoll_cleanup() is either called

4) Now the second target tries to clean up
   - The second cleanup fails because np->dev->npinfo is already NULL.
     * In this case, ops->ndo_netpoll_cleanup() was never called, and
       the skb pool is not cleaned as well (for the second netpoll
       instance)
  - This leaks npinfo and skbpool skbs, which is clearly reported by
    kmemleak.

Revert commit efa95b01da18 ("netpoll: fix use after free") and adds
clarifying comments emphasizing that npinfo cleanup should only happen
once the refcount reaches zero, ensuring stable and correct netpoll
behavior.

## Which versions are affected by CVE-2025-68245?


## How do I fix CVE-2025-68245?

Apply the vendor's patch.

## Is CVE-2025-68245 being exploited?

There is no known exploitation of CVE-2025-68245 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68245 and fix it if it is affected.

What it is: CVE-2025-68245 is an use after free vulnerability in Linux, published on 16 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-2025-68245 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-2025-68245/ (Markdown: https://insights.sbomify.com/CVE-2025-68245/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68245
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68245
- OSV: https://osv.dev/vulnerability/CVE-2025-68245

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68245/
Summaries are generated and may contain mistakes; the official description above is the record.