CVE-2026-16148: Kernel panic in the it82xx2 USB device controller driver via re-initialization of a busy delayable work item
The ITE it82xx2 USB device-controller driver initialized its bus-suspend detection work with kworkinitdelayable(&priv->suspendedwork, suspendedhandler) inside it82xx2enable() (the driver's .enable op) in drivers/usb/udc/udcit82xx2.c. This work item is scheduled essentially continuously while the USB bus is active: the interrupt handler reschedules it on every SOF frame and suspendedhandler() reschedules itself, so its timeout node is normally linked in the kernel timeout list / a workqueue pending queue.
kworkinitdelayable() (kernel/work.c) unconditionally overwrites the entire kworkdelayable structure, including its timeout and queue linkage, with no busy check. Because it82xx2disable() does not cancel the work, a normal disable-then-enable cycle re-runs api->enable() (udcenable() only rejects a redundant enable, not a re-enable after disable) and re-initializes the still-pending work in place, corrupting the kernel timeout/workqueue linked lists and causing a kernel panic.
An external USB host — for example a host performing USB DFU detach (dfu-util --detach) or forcing repeated attach/reset/re-enumeration — drives the udcdisable()/udcenable() transitions and controls suspend/resume timing, so it can arrange for the suspend work to be pending across a re-enable. This yields an unauthenticated denial of service (kernel panic) reachable across the USB boundary from a removable, physically-connected host, with no confidentiality or integrity impact demonstrated.
The fix moves the kworkinitdelayable() call into the one-time preinit function so the work is initialized exactly once, eliminating the re-initialization of an in-use item.
Affected Software
Event History
Frequently Asked Questions
Who is exposed to this issue?
Devices using the ITE it82xx2 USB device-controller driver are exposed when their USB device interface is connected to an external host. The attack vector is physical, so a remote network-only attacker is not described.
What does an attacker need to do to trigger the panic?
An external USB host must cause a disable-then-enable transition while the driver's delayable bus-suspend work remains pending. The described triggers include a DFU detach request and repeated attach, reset, or re-enumeration activity; no privileges or user interaction are required.
What is the impact if exploitation succeeds?
Re-initializing the pending delayable work item corrupts kernel timeout or workqueue linked lists and causes a kernel panic. The reported impact is denial of service through loss of availability, with no confidentiality or integrity impact stated.
Is ordinary USB activity relevant to exploitation?
Yes. While the USB bus is active, the affected work item is scheduled continuously through USB SOF-frame handling and by its own handler. This makes it likely to remain pending when a host drives the disable-then-enable sequence.