R_API int r_anal_bb(RAnal *anal, RAnalBlock *bb, ut64 addr, ut8 *buf, ut64 len, int head) {
	RAnalOp *op = NULL;
	int oplen, idx = 0;

	if (bb->addr == -1) {
		bb->addr = addr;
	}
	len -= 16; // XXX: hack to avoid segfault by x86im
	while (idx < len) {
		if (!(op = r_anal_op_new ())) {
			eprintf ("Error: new (op)\n");
			return R_ANAL_RET_ERROR;
		}
		if ((oplen = r_anal_op (anal, op, addr + idx, buf + idx, len - idx, R_ANAL_OP_MASK_VAL)) == 0) {
			r_anal_op_free (op);
			op = NULL;
			if (idx == 0) {
				VERBOSE_ANAL eprintf ("Unknown opcode at 0x%08"PFMT64x"\n", addr+idx);
				return R_ANAL_RET_END;
			}
			break;
		}
		if (oplen < 1) {
			goto beach;
		}
		r_anal_bb_set_offset (bb, bb->ninstr++, addr + idx - bb->addr);
		idx += oplen;
		bb->size += oplen;
		if (head) {
			bb->type = R_ANAL_BB_TYPE_HEAD;
		}
		switch (op->type) {
		case R_ANAL_OP_TYPE_CMP:
			r_anal_cond_free (bb->cond);
			bb->cond = r_anal_cond_new_from_op (op);
			break;
		case R_ANAL_OP_TYPE_CJMP:
			if (bb->cond) {
				bb->cond->type = R_ANAL_COND_EQ;
			} else VERBOSE_ANAL eprintf ("Unknown conditional for block 0x%"PFMT64x"\n", bb->addr);
			bb->conditional = 1;
			bb->fail = op->fail;
			bb->jump = op->jump;
			bb->type |= R_ANAL_BB_TYPE_BODY;
			goto beach;
		case R_ANAL_OP_TYPE_JMP:
			bb->jump = op->jump;
			bb->type |= R_ANAL_BB_TYPE_BODY;
			goto beach;
		case R_ANAL_OP_TYPE_UJMP:
		case R_ANAL_OP_TYPE_IJMP:
		case R_ANAL_OP_TYPE_RJMP:
		case R_ANAL_OP_TYPE_IRJMP:
			bb->type |= R_ANAL_BB_TYPE_FOOT;
			goto beach;
		case R_ANAL_OP_TYPE_RET:
			bb->type |= R_ANAL_BB_TYPE_LAST;
			goto beach;
		case R_ANAL_OP_TYPE_LEA:
		{
			RAnalValue *src = op->src[0];
			if (src && src->reg && anal->reg) {
				const char *pc = anal->reg->name[R_REG_NAME_PC];
				RAnalValue *dst = op->dst;
				if (dst && dst->reg && !strcmp (src->reg->name, pc)) {
					int memref = anal->bits/8;
					ut8 b[8];
					ut64 ptr = idx+addr+src->delta;
					anal->iob.read_at (anal->iob.io, ptr, b, memref);
					r_anal_xrefs_set (anal, addr+idx-op->size, ptr, R_ANAL_REF_TYPE_DATA);
				}
			}
		}
		}
		r_anal_op_free (op);
	}

	return bb->size;
beach:
	r_anal_op_free (op);
	return R_ANAL_RET_END;
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.