CVE-2026-97972 net: macb: put the "mdio" child node reference on success
A reference counting bug in the Linux kernel macb network driver causes a memory leak, potentially leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97972?
CVE-2026-97972 is a memory corruption vulnerability in Linux, published on 25 Sep 2026. 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: macb: put the "mdio" child node reference on success
macb_mii_init() holds the reference returned by of_get_child_by_name() for macb_mdiobus_register() and drops it only on the error paths, so every successful probe leaks a node reference. On a CM5, overlay removal after four bind cycles reports
OF: ERROR: memory leak, expected refcount 1 instead of 5
Drop the reference after registration, where __mdiobus_register() has already taken its own for the lifetime of the bus.
Which versions are affected by CVE-2026-97972?
How do I fix CVE-2026-97972?
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-2026-97972 being exploited?
There is no known exploitation of CVE-2026-97972 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-97972, DEBIAN-CVE-2026-97972, GHSA-234h-4jcx-ffp3, UBUNTU-CVE-2026-97972.