# CVE-2025-68779: net/mlx5e: Avoid unregistering PSP twice

> A double unregister bug in the Linux kernel mlx5e driver causes a use-after-free, potentially leading to system crashes or code execution.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Jan 2026
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2025-68779, GHSA-7crx-7pfp-hg6j, ROOT-OS-UBUNTU-2204-CVE-2025-68779, ROOT-OS-UBUNTU-2404-CVE-2025-68779, UBUNTU-CVE-2025-68779

## What is CVE-2025-68779?

CVE-2025-68779 is an use after free vulnerability in Linux, published on 13 Jan 2026. 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:

net/mlx5e: Avoid unregistering PSP twice

PSP is unregistered twice in:
_mlx5e_remove -> mlx5e_psp_unregister
mlx5e_nic_cleanup -> mlx5e_psp_unregister

This leads to a refcount underflow in some conditions:
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 2 PID: 1694 at lib/refcount.c:28 refcount_warn_saturate+0xd8/0xe0
[...]
 mlx5e_psp_unregister+0x26/0x50 [mlx5_core]
 mlx5e_nic_cleanup+0x26/0x90 [mlx5_core]
 mlx5e_remove+0xe6/0x1f0 [mlx5_core]
 auxiliary_bus_remove+0x18/0x30
 device_release_driver_internal+0x194/0x1f0
 bus_remove_device+0xc6/0x130
 device_del+0x159/0x3c0
 mlx5_rescan_drivers_locked+0xbc/0x2a0 [mlx5_core]
[...]

Do not directly remove psp from the _mlx5e_remove path, the PSP cleanup
happens as part of profile cleanup.

## Which versions are affected by CVE-2025-68779?


## How do I fix CVE-2025-68779?

Apply the vendor's patch.

## Is CVE-2025-68779 being exploited?

There is no known exploitation of CVE-2025-68779 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-68779 and fix it if it is affected.

What it is: CVE-2025-68779 is an use after free vulnerability in Linux, published on 13 Jan 2026. 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-2025-68779 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-2025-68779/ (Markdown: https://insights.sbomify.com/CVE-2025-68779/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-68779
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-68779
- OSV: https://osv.dev/vulnerability/CVE-2025-68779

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-68779/
Summaries are generated and may contain mistakes; the official description above is the record.