Linux Kernel PCI: Mediatek Refcount Leak Vulnerability

A refcount leak vulnerability has been identified in the Linux kernel's PCI subsystem for Mediatek devices. The issue arises in the mtk_pcie_subsys_powerup() function, where the of_find_compatible_node() function returns a node pointer with an incremented refcount. The vulnerability occurs because the refcount is not properly released after use. The missing of_node_put() call has been added to address this issue.

Impact

The vulnerability could lead to a memory management issue, where reference counts are not properly managed, potentially causing resource leaks or other unintended behavior in the PCI subsystem.