CVE-2022-49016 net: mdiobus: fix unbalanced node reference count
A memory leak in the Linux kernel MDIO bus driver can lead to resource exhaustion and denial of service when specific device tree configurations are enabled.
- 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-2022-49016?
CVE-2022-49016 is a medium-severity memory corruption vulnerability in Linux kernel, published on 21 Oct 2024. 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: 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.
Weakness: CWE-401
Which versions are affected by CVE-2022-49016?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49016?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2022-49016 being exploited?
There is no known exploitation of CVE-2022-49016 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49016, GHSA-5cp3-hg96-hvr9, UBUNTU-CVE-2022-49016.