Linux Kernel Null Pointer Dereference Vulnerability in mtk-pmic-keys Input Handling

A null pointer dereference vulnerability has been identified in the Linux kernel's mtk-pmic-keys input handling. The issue arises in the mtk_pmic_keys_probe function, where the 'regs' parameter is only assigned if the button is recognized in the device tree. On hardware with floating buttons, that node is likely removed, leading to a null pointer dereference. The vulnerability can be addressed by using the 'regs' structure, which is defined for all supported platforms, ensuring that the key register is set even if the button is disabled, as the interrupt will not be activated.

Impact

Exploitation of this vulnerability leads to a null pointer dereference, causing a crash or undefined behavior in the kernel.