overrun screw

overrun screw n.  [C programming] A variety of {fandango
   on core} produced by scribbling past the end of an array (C
   implementations typically have no checks for this error).  This is
   relatively benign and easy to spot if the array is static; if it is
   auto, the result may be to {smash the stack} -- often resulting
   in {heisenbug}s of the most diabolical subtlety.  The term
   `overrun screw' is used esp. of scribbles beyond the end of
   arrays allocated with `malloc(3)'; this typically trashes the
   allocation header for the next block in the {arena}, producing
   massive lossage within malloc and often a core dump on the next
   operation to use `stdio(3)' or `malloc(3)' itself.  See
   {spam}, {overrun}; see also {memory leak}, {memory
   smash}, {aliasing bug}, {precedence lossage}, {fandango on
   core}, {secondary damage}.