ZwProtectVirtualMemory() returning NTSTATUS 0xC0000018

I am trying to call ZwProtectVirtualMemory() from my driver, when I call it with parameters I think are correct nothing happens and NTSTATUS 0xC0000018 is returned (STATUS_CONFLICTING_ADDRESSES).

Here I grab the PEPROCESS pointer.

if (!NT_SUCCESS(PsLookupProcessByProcessId((void*)request->target_pid, &target_process)))

I know this is correct because I can use this to read and write with MmCopyVirtualMemory. Then I attempt to call ZwProtectVirtualMemory() like so first I context switch with KeStackAttachProcess then I attempt to call it.

KAPC_STATE apc;
KeStackAttachProcess(target_process, &apc); 
{
    auto protect_base = (void*)request->target_addr; // ZwProtectVirtualMemory writes to target_addr
    unsigned long old_prot = 0;
    DbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, "base : %X size : %i protection : %X" , protect_base, request->size, request->protection);
    status = ZwProtectVirtualMemory(ZwCurrentProcess(), &protect_base, (unsigned long*)&request->size, request->protection, &old_prot);
    DbgPrintEx(DPFLTR_IHVDRIVER_ID, DPFLTR_ERROR_LEVEL, "returned : %X", status);
}
KeUnstackDetachProcess(&apc);

The first DbgPrintEx prints the parameters I expect and the second one returns 0xC0000018 like previously stated.