overrun screw

A variety of fandango on core produced by a C program

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 especially of scribbles

beyond the end of arrays allocated with malloc; this

typically overwrites 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 or

malloc itself.

See spam, overrun; see also memory leak, memory smash,

aliasing bug, precedence lossage, fandango on core,

secondary damage.

(1995-01-19)