# CVE-2026-45907: net/mlx5e: Fix deadlocks between devlink and netdev instance locks

> A deadlock in the Linux kernel mlx5e driver can cause a denial of service when devlink and netdev locks are acquired in the wrong order.

- **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:** 27 May 2026
- **Updated:** 27 May 2026
- **Also known as:** BELL-CVE-2026-45907, DEBIAN-CVE-2026-45907, GHSA-jpj8-hw92-vqgg, UBUNTU-CVE-2026-45907

## What is CVE-2026-45907?

CVE-2026-45907 is a medium-severity vulnerability in Linux kernel, published on 27 May 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: Fix deadlocks between devlink and netdev instance locks

In the mentioned "Fixes" commit, various work tasks triggering devlink
health reporter recovery were switched to use netdev_trylock to protect
against concurrent tear down of the channels being recovered. But this
had the side effect of introducing potential deadlocks because of
incorrect lock ordering.

The correct lock order is described by the init flow:
probe_one -> mlx5_init_one (acquires devlink lock)
-> mlx5_init_one_devl_locked -> mlx5_register_device
-> mlx5_rescan_drivers_locked -...-> mlx5e_probe -> _mlx5e_probe
-> register_netdev (acquires rtnl lock)
-> register_netdevice (acquires netdev lock)
=> devlink lock -> rtnl lock -> netdev lock.

But in the current recovery flow, the order is wrong:
mlx5e_tx_err_cqe_work (acquires netdev lock)
-> mlx5e_reporter_tx_err_cqe -> mlx5e_health_report
-> devlink_health_report (acquires devlink lock => boom!)
-> devlink_health_reporter_recover
-> mlx5e_tx_reporter_recover -> mlx5e_tx_reporter_recover_from_ctx
-> mlx5e_tx_reporter_err_cqe_recover

The same pattern exists in:
mlx5e_reporter_rx_timeout
mlx5e_reporter_tx_ptpsq_unhealthy
mlx5e_reporter_tx_timeout

Fix these by moving the netdev_trylock calls from the work handlers
lower in the call stack, in the respective recovery functions, where
they are actually necessary.

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2026-45907?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-45907?

Apply the vendor's patch.

## Is CVE-2026-45907 being exploited?

There is no known exploitation of CVE-2026-45907 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-2026-45907 and fix it if it is affected.

What it is: CVE-2026-45907 is a medium-severity vulnerability in Linux kernel, published on 27 May 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-2026-45907 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-2026-45907/ (Markdown: https://insights.sbomify.com/CVE-2026-45907/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45907
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45907
- OSV: https://osv.dev/vulnerability/CVE-2026-45907

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45907/
Summaries are generated and may contain mistakes; the official description above is the record.