CVE-2026-68338

Status: UPDATED  |  Advisory ID: CVE-2026-68338

Key Details

Affected Products, Subsystems & Sectors

What to Know

In the Linux kernel, the following vulnerability has been resolved:

net/packet: avoid fanout hook re-registration after unregister

packet_set_ring() temporarily detaches a socket from packet delivery while

reconfiguring its ring. It records the previous running state, clears

po->num, unregisters the protocol hook when needed, drops po->bind_lock,

and later restores po->num and re-registers the hook from the saved

was_running value.

That unlocked window can race with NETDEV_UNREGISTER. The notifier can

observe the socket as not running, skip __unregister_prot_hook(), and

invalidate the per-socket binding by setting po->ifindex to -1 and clearing

po->prot_hook.dev. A one-member fanout group can still retain its shared

fanout hook device pointer. When packet_set_ring() resumes, re-registering

solely from the stale was_running state can re-add the fanout hook after

the device has been unregistered.

Treat po->ifindex == -1 as an invalidated binding after reacquiring

po->bind_lock. This is distinct from ifindex 0, the normal

unbound/wildcard state: ifindex -1 marks an existing device binding that

was invalidated when the device was unregistered. Restore po->num as

before, but do not re-register the hook if device unregister already

detached the socket. (NVD)

What to Do

Monitor Linux's web page for any future patch releases.

References