Local privilege escalation via pKVM size overflow

Integer overflow in Android kernel pKVM allows local users to escalate privileges through a crafted host-to-guest memory-sharing request. __pkvm_host_share_guest in mem_protect.c adds an attacker-controlled address and size without rejecting wraparound, so range validation accepts a truncated end boundary and permits an out-of-bounds write. No prior execution privileges or user interaction are required; successful exploitation grants elevated local control over the device.