CVE-2021-47416: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: phy: mdio: fix memory leak Syzbot reported memory leak in MDIO bus interface, the problem was in wrong state logic. MDIOBUS_ALLOCATED indicates 2 states: 1. Bus is only allocated 2. Bus allocated and __mdiobus_register() fails, but device_register() was called In case of device_register() has been called we should call put_device() to correctly free the memory allocated for this device, but mdiobus_free() calls just kfree(dev) in case of MDIOBUS_ALLOCATED state To avoid this behaviour we need to set bus->state to MDIOBUS_UNREGISTERED _before_ calling device_register(), because put_device() should be called even in case of device_register() failure.

Affected products

• Linux Linux Kernel: from 2.6.28, before 4.4.289 (fixed in 4.4.289); from 4.5, before 4.9.287 (fixed in 4.9.287); from 4.10, before 4.14.251 (fixed in 4.14.251); from 4.15, before 4.19.211 (fixed in 4.19.211); from 4.20, before 5.4.153 (fixed in 5.4.153); from 5.5, before 5.10.73 (fixed in 5.10.73); …

Published 2024-05-21. Last modified 2026-06-17.