CVE-2019-13590 — Integer Overflow or Wraparound in Exchange Project Sound Exchange

An issue was discovered in libsox.a in SoX 14.4.2. In sox-fmt.h (startread function), there is an integer overflow on the result of integer addition (wraparound to 0) fed into the lsx_calloc macro that wraps malloc. When a NULL pointer is returned, it is used without a prior check that it is a valid pointer, leading to a NULL pointer dereference on lsx_readbuf in formats_i.c.