Junglewise Threat Intelligence

CVE-2025-21701: Linux Kernel race condition in ethtool Netlink operations

CVE-2025-21701 · Severity: medium · CVSS 4.7 · Published 2025-02-13

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A race condition vulnerability was identified in the Linux kernel's networking subsystem. It occurs when a network device is being removed from the system at the same time its configuration is being modified via the ethtool utility. An exploit could lead to a system crash or instability, potentially causing a denial of service for the affected machine.

Technical details

A race condition exists between network device unregistration and ethtool Netlink (ethnl) operations. The vulnerability is rooted in the fact that 'unregister_netdevice_many_notify' can execute before the 'rtnl' lock section of certain ethnl operations (such as 'set_channels'). This can result in resources, like the RSS lock, being destroyed while still in use by the configuration path. The fix expands the check in 'ethnl_ops_begin' to deny operations on any device that has entered the 'NETREG_UNREGISTERING' state or further. This issue specifically affects the Netlink interface and not the older ioctl-based ethtool interface.

Affected products

  • Linux Linux Kernel 5.10.87 to 5.11, 5.15.8 to 5.15.179, 5.16.1 to 6.1.129, 6.2 to 6.6.76, 6.7 to 6.12.13, 6.13 to 6.13.2

Timeline

  • 2025-01-16: patched: Initial patch submitted by Antoine Tenart
  • 2025-02-13: disclosed: CVE-2025-21701 published

References

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