CVE-2022-49016: net: mdiobus: fix unbalanced node reference count

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-10-21 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: net: mdiobus: fix unbalanced node reference count I got the following report while doing device(mscc-miim) load test with CONFIG_OF_UNITTEST and CONFIG_OF_DYNAMIC enabled: OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /spi/soc@0/mdio@7107009c/ethernet-phy@0 If the 'fwnode' is not an acpi node, the refcount is get in fwnode_mdiobus_phy_device_register(), but it has never been put when the device is freed in the normal path. So call fwnode_handle_put() in phy_device_release() to avoid leak. If it's an acpi node, it has never been get, but it's put in the error path, so call fwnode_handle_get() before phy_device_register() to keep get/put operation balanced.

Affected products

Linux kernel: from 5.14 before 5.15.82; from 5.16 before 6.0.12; 6.1-rc1, 6.1-rc2, 6.1-rc3, 6.1-rc4, 6.1-rc5, 6.1-rc6 (+1) — fixed in 5.15.82, 6.0.12

How to fix

Upgrade to a fixed version: Linux kernel 5.15.82, 6.0.12. Check the vendor advisory for mitigations.

References

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