# CVE-2025-39832: net/mlx5: Fix lockdep assertion on sync reset unload event

> A race condition in the mlx5 driver causes a lockdep assertion failure during sync reset, potentially leading to a 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:** 16 Sep 2025
- **Updated:** 11 May 2026
- **Also known as:** AZL-67407, BELL-CVE-2025-39832, DEBIAN-CVE-2025-39832, GHSA-qcgc-5p4x-hxc8, ROOT-OS-DEBIAN-13-CVE-2025-39832, ROOT-OS-UBUNTU-2404-CVE-2025-39832, UBUNTU-CVE-2025-39832

## What is CVE-2025-39832?

CVE-2025-39832 is a medium-severity vulnerability in Linux kernel, published on 16 Sep 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:

net/mlx5: Fix lockdep assertion on sync reset unload event

Fix lockdep assertion triggered during sync reset unload event. When the
sync reset flow is initiated using the devlink reload fw_activate
option, the PF already holds the devlink lock while handling unload
event. In this case, delegate sync reset unload event handling back to
the devlink callback process to avoid double-locking and resolve the
lockdep warning.

Kernel log:
WARNING: CPU: 9 PID: 1578 at devl_assert_locked+0x31/0x40
[...]
Call Trace:
<TASK>
 mlx5_unload_one_devl_locked+0x2c/0xc0 [mlx5_core]
 mlx5_sync_reset_unload_event+0xaf/0x2f0 [mlx5_core]
 process_one_work+0x222/0x640
 worker_thread+0x199/0x350
 kthread+0x10b/0x230
 ? __pfx_worker_thread+0x10/0x10
 ? __pfx_kthread+0x10/0x10
 ret_from_fork+0x8e/0x100
 ? __pfx_kthread+0x10/0x10
 ret_from_fork_asm+0x1a/0x30
</TASK>

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2025-39832?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-39832?

Apply the vendor's patch.

## Is CVE-2025-39832 being exploited?

There is no known exploitation of CVE-2025-39832 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-2025-39832 and fix it if it is affected.

What it is: CVE-2025-39832 is a medium-severity vulnerability in Linux kernel, published on 16 Sep 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-2025-39832 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-2025-39832/ (Markdown: https://insights.sbomify.com/CVE-2025-39832/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-39832
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-39832
- OSV: https://osv.dev/vulnerability/CVE-2025-39832

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-39832/
Summaries are generated and may contain mistakes; the official description above is the record.