CVE-2026-53323 net: dsa: remove redundant netdev_lock_ops() from conduit ethtool ops

Medium 5.5 Published Updated

A deadlock in the Linux kernel DSA subsystem causes a denial of service when ethtool operations are performed on conduit devices.

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

What is CVE-2026-53323?

CVE-2026-53323 is a medium-severity vulnerability in Linux kernel, published on 26 Jun 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: dsa: remove redundant netdev_lock_ops() from conduit ethtool ops

DSA replaces the conduit (master) device's ethtool_ops with its own wrappers that aggregate stats from both the conduit and DSA switch ports. Taking the lock again inside the DSA wrappers causes a deadlock.

Stumbled upon this when booting qemu with fbnic and CONFIG_NET_DSA_LOOP=y (which looks like some kind of testing device that auto-populates the ports of eth0). `ethtool -i` is enough to deadlock. This means we have basically zero coverage for DSA stuff with real ops locked devs.

Remove the redundant netdev_lock_ops()/netdev_unlock_ops() calls from the DSA conduit ethtool wrappers.

Weakness: CWE-667

Which versions are affected by CVE-2026-53323?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-53323?

Apply the vendor's patch.

Is CVE-2026-53323 being exploited?

There is no known exploitation of CVE-2026-53323 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as BELL-CVE-2026-53323, DEBIAN-CVE-2026-53323, GHSA-vg65-jq85-8q85, UBUNTU-CVE-2026-53323.

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