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 heisenbugs 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
malloc(3) itself. See
spam, overrun; see also memory leak, memory smash, aliasing bug, precedence lossage, fandango on core, secondary damage.