aliasing bug n. A class of subtle programming errors that can arise in
   code that does dynamic allocation, esp. via `malloc(3)' or equivalent.
   If several pointers address (`aliases for') a given hunk of storage, it
   may happen that the storage is freed or reallocated (and thus moved)
   through one alias and then referenced through another, which may lead to
   subtle (and possibly intermittent) lossage depending on the state and
   the allocation history of the malloc {arena}. Avoidable by use of
   allocation strategies that never alias allocated core, or by use of
   higher-level languages, such as {LISP}, which employ a garbage collector
   (see {GC}). Also called a {stale pointer bug}. See also {precedence
   lossage}, {smash the stack}, {fandango on core}, {memory leak}, {memory
   smash}, {overrun screw}, {spam}.

   Historical note: Though this term is nowadays associated with C
   programming, it was already in use in a very similar sense in the
   Algol-60 and FORTRAN communities in the 1960s.


Source: The Jargon File