/usr/include/CGAL/QP_solver/ is in libcgal-dev 4.2-5ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/CGAL/QP_solver/Initialization.h
/usr/include/CGAL/QP_solver/QP__filtered_base.h
/usr/include/CGAL/QP_solver/QP__filtered_base_impl.h
/usr/include/CGAL/QP_solver/QP__partial_base.h
/usr/include/CGAL/QP_solver/QP_basis_inverse.h
/usr/include/CGAL/QP_solver/QP_basis_inverse_impl.h
/usr/include/CGAL/QP_solver/QP_exact_bland_pricing.h
/usr/include/CGAL/QP_solver/QP_full_exact_pricing.h
/usr/include/CGAL/QP_solver/QP_full_filtered_pricing.h
/usr/include/CGAL/QP_solver/QP_functions_impl.h
/usr/include/CGAL/QP_solver/QP_partial_exact_pricing.h
/usr/include/CGAL/QP_solver/QP_partial_filtered_pricing.h
/usr/include/CGAL/QP_solver/QP_pricing_strategy.h
/usr/include/CGAL/QP_solver/QP_solution_impl.h
/usr/include/CGAL/QP_solver/QP_solver.h
/usr/include/CGAL/QP_solver/QP_solver_bounds_impl.h
/usr/include/CGAL/QP_solver/QP_solver_impl.h
/usr/include/CGAL/QP_solver/QP_solver_nonstandardform_impl.h
/usr/include/CGAL/QP_solver/Unbounded_direction.h
/usr/include/CGAL/QP_solver/assertions.h
/usr/include/CGAL/QP_solver/basic.h
/usr/include/CGAL/QP_solver/debug.h
/usr/include/CGAL/QP_solver/functors.h