Application crash via Pha iterator underflow

Stack-based buffer overflow in libxmp 4.6.2 and earlier allows attackers to crash a consuming application via a malformed Pha module. In depack_pha, an input-derived iterator can wrap below INT_MIN, and truncated modulo then indexes the stack-based onote and ocpt arrays below their bounds. Exploitation requires an application linked against the library to load the crafted tracker file; the resulting out-of-bounds reads and writes can corrupt stack data.