CVE-2026-23129

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> dpll: Prevent duplicate registrations<br /> <br /> Modify the internal registration helpers dpll_xa_ref_{dpll,pin}_add()<br /> to reject duplicate registration attempts.<br /> <br /> Previously, if a caller attempted to register the same pin multiple<br /> times (with the same ops, priv, and cookie) on the same device, the core<br /> silently increments the reference count and return success. This behavior<br /> is incorrect because if the caller makes these duplicate registrations<br /> then for the first one dpll_pin_registration is allocated and for others<br /> the associated dpll_pin_ref.refcount is incremented. During the first<br /> unregistration the associated dpll_pin_registration is freed and for<br /> others WARN is fired.<br /> <br /> Fix this by updating the logic to return `-EEXIST` if a matching<br /> registration is found to enforce a strict "register once" policy.