Check various overflows.
Utilize GCC builtins in many places which had less robust (or no) overflow checks.
Change a realloc in libmount/util.h
to reallocarray, while we're at it.
Utilize GCC builtins in many places which had less robust (or no) overflow checks.
Change a realloc in libmount/util.h
to reallocarray, while we're at it.