Linux Kernel PHY ethnl_req_get_phydev null pointer dereference

Summaryinfo

A vulnerability described as problematic has been identified in Linux Kernel. This vulnerability affects the function ethnl_req_get_phydev of the component PHY. The manipulation results in null pointer dereference. This vulnerability was named CVE-2026-64228. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability classified as problematic has been found in Linux Kernel (unknown version). Affected is the function ethnl_req_get_phydev of the component PHY. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: net: ethtool: phy: avoid NULL deref when PHY driver is unbound phydev->drv can become NULL while the phy_device is still attached to its net_device, namely after the PHY driver is unbound via sysfs: echo <mdio_id> > /sys/bus/mdio_bus/drivers/<phy_drv>/unbind phy_remove() clears phydev->drv but doesn't call phy_detach(), so the phy_device stays in the link topology xarray and ethnl_req_get_phydev() still hands it back. ETHTOOL_MSG_PHY_GET then oopses on: rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL); drvname is already treated as optional by phy_reply_size(), phy_fill_reply() and phy_cleanup_data(), so just skip the allocation when there is no driver bound.

This vulnerability is traded as CVE-2026-64228. The exploitability is told to be easy. It is possible to launch the attack remotely. Additional levels of successful authentication are necessary for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 330189 (Linux Distros Unpatched Vulnerability : CVE-2026-64228), which helps to determine the existence of the flaw in a target environment.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Tenable (330189) and CERT Bund (WID-SEC-2026-2527). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Red Hat OpenShift
• RESF Rocky Linux
• SUSE Linux
• Ubuntu Linux
• Oracle Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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