CVE-2025-71228

In the Linux kernel, the following vulnerability has been resolved:

LoongArch: Set correct protection_map[] for VM_NONE/VM_SHARED

For 32BIT platform _PAGE_PROTNONE is 0, so set a VMA to be VM_NONE or
VM_SHARED will make pages non-present, then cause Oops with kernel page
fault.

Fix it by set correct protection_map[] for VM_NONE/VM_SHARED, replacing
_PAGE_PROTNONE with _PAGE_PRESENT.