Overcommit is a very deliberate feature, but its time may have passed. Keep in mind this is all from a time when RAM was so expensive swapping to spinning disks was a requirement just to run programs taking advantage of a 32-bit address space.

You can tune the overcommit ratio on Linux, but if memory serves (no pun intended) the last time I played with eliminating overcommit, a bunch of programs that liked to allocate big virtual address spaces ceased functioning.