HP-UX on PA-RISC had an upward-growing stack. In practice, various exploits were developed which adapted to the changed direction of the stack.
One source from a few mins of searching: https://phrack.org/issues/58/11
One source from a few mins of searching: https://phrack.org/issues/58/11
As noted, stack growing up doesn't prevent all stack overflows, but it makes it less trivially easy to overwrite a return address. Bounded strings also made it less trivially easy to create string buffer overflows.