Linux Kernel i2c PIIX4 EFCH MMIO Memory Leak Vulnerability

A memory leak vulnerability has been introduced in the Linux kernel's i2c PIIX4 EFCH MMIO support. This leak occurs because the function release_resource() only removes the resource from the management tree without freeing the associated memory. The correct function, release_mem_region(), which does free the memory, needs to be used instead. This change also restores symmetry between the legacy and MMIO handling.

Impact

Exploitation of this vulnerability leads to a memory leak, where allocated memory is not properly released, potentially causing increased memory usage and degradation of system performance over time.