# CVE-2026-23035: net/mlx5e: Pass netdev to mlx5e_destroy_netdev instead of priv

> A local attacker with high privileges can trigger a kernel null pointer dereference in the mlx5e driver during device removal, causing a system crash.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 Jan 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-77232, BELL-CVE-2026-23035, DEBIAN-CVE-2026-23035, GHSA-5wr5-mxmx-fvmr, ROOT-OS-DEBIAN-12-CVE-2026-23035, ROOT-OS-DEBIAN-13-CVE-2026-23035, ROOT-OS-UBUNTU-2204-CVE-2026-23035, ROOT-OS-UBUNTU-2404-CVE-2026-23035, UBUNTU-CVE-2026-23035

## What is CVE-2026-23035?

CVE-2026-23035 is a vulnerability in Linux, published on 31 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: Pass netdev to mlx5e_destroy_netdev instead of priv

mlx5e_priv is an unstable structure that can be memset(0) if profile
attaching fails.

Pass netdev to mlx5e_destroy_netdev() to guarantee it will work on a
valid netdev.

On mlx5e_remove: Check validity of priv->profile, before attempting
to cleanup any resources that might be not there.

This fixes a kernel oops in mlx5e_remove when switchdev mode fails due
to change profile failure.

$ devlink dev eswitch set pci/0000:00:03.0 mode switchdev
Error: mlx5_core: Failed setting eswitch to offloads.
dmesg:
workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12
mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: new profile init failed, -12
workqueue: Failed to create a rescuer kthread for wq "mlx5e": -EINTR
mlx5_core 0012:03:00.1: mlx5e_netdev_init_profile:6214:(pid 37199): mlx5e_priv_init failed, err=-12
mlx5_core 0012:03:00.1 gpu3rdma1: mlx5e_netdev_change_profile: failed to rollback to orig profile, -12

$ devlink dev reload pci/0000:00:03.0 ==> oops

BUG: kernel NULL pointer dereference, address: 0000000000000370
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 15 UID: 0 PID: 520 Comm: devlink Not tainted 6.18.0-rc5+ #115 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
RIP: 0010:mlx5e_dcbnl_dscp_app+0x23/0x100
RSP: 0018:ffffc9000083f8b8 EFLAGS: 00010286
RAX: ffff8881126fc380 RBX: ffff8881015ac400 RCX: ffffffff826ffc45
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8881035109c0
RBP: ffff8881035109c0 R08: ffff888101e3e838 R09: ffff888100264e10
R10: ffffc9000083f898 R11: ffffc9000083f8a0 R12: ffff888101b921a0
R13: ffff888101b921a0 R14: ffff8881015ac9a0 R15: ffff8881015ac400
FS:  00007f789a3c8740(0000) GS:ffff88856aa59000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000370 CR3: 000000010b6c0001 CR4: 0000000000370ef0
Call Trace:
 <TASK>
 mlx5e_remove+0x57/0x110
 device_release_driver_internal+0x19c/0x200
 bus_remove_device+0xc6/0x130
 device_del+0x160/0x3d0
 ? devl_param_driverinit_value_get+0x2d/0x90
 mlx5_detach_device+0x89/0xe0
 mlx5_unload_one_devl_locked+0x3a/0x70
 mlx5_devlink_reload_down+0xc8/0x220
 devlink_reload+0x7d/0x260
 devlink_nl_reload_doit+0x45b/0x5a0
 genl_family_rcv_msg_doit+0xe8/0x140

## Which versions are affected by CVE-2026-23035?


## How do I fix CVE-2026-23035?

Apply the vendor's patch.

## Is CVE-2026-23035 being exploited?

There is no known exploitation of CVE-2026-23035 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-23035 and fix it if it is affected.

What it is: CVE-2026-23035 is a vulnerability in Linux, published on 31 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-2026-23035 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-2026-23035/ (Markdown: https://insights.sbomify.com/CVE-2026-23035/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23035
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23035
- OSV: https://osv.dev/vulnerability/CVE-2026-23035

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23035/
Summaries are generated and may contain mistakes; the official description above is the record.