Is there any harm in installing too much RAM?

I'm aware that you can use RAM that's of a higher or lower speed
than the computer expects. (It'll just run at whatever
the lower speed is).

But what if you put in a higher *amount* of memory
than the computer expects?
For example, suppose you have an old desktop computer
that has 2 slots, each with a maximum capacity of 128MB each.
If you put in 2 RAM modules, each with 512MB, the computer
will likely still work (although it'll only recognize and use
the first 128MB of each module).

But besides wasting RAM, is there any actual harm in doing this?
For example, can this cause the operating system to malfunction
or for data to be corrupted?

....