/usr/include/suitesparse/ is in libsuitesparse-dev 1:4.2.1-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/suitesparse/SuiteSparseQR.hpp
/usr/include/suitesparse/SuiteSparseQR_C.h
/usr/include/suitesparse/SuiteSparseQR_definitions.h
/usr/include/suitesparse/SuiteSparse_config.h
/usr/include/suitesparse/amd.h
/usr/include/suitesparse/amd_internal.h
/usr/include/suitesparse/btf.h
/usr/include/suitesparse/btf_internal.h
/usr/include/suitesparse/camd.h
/usr/include/suitesparse/camd_internal.h
/usr/include/suitesparse/ccolamd.h
/usr/include/suitesparse/cholmod.h
/usr/include/suitesparse/cholmod_blas.h
/usr/include/suitesparse/cholmod_camd.h
/usr/include/suitesparse/cholmod_check.h
/usr/include/suitesparse/cholmod_cholesky.h
/usr/include/suitesparse/cholmod_complexity.h
/usr/include/suitesparse/cholmod_config.h
/usr/include/suitesparse/cholmod_core.h
/usr/include/suitesparse/cholmod_internal.h
/usr/include/suitesparse/cholmod_io64.h
/usr/include/suitesparse/cholmod_matrixops.h
/usr/include/suitesparse/cholmod_modify.h
/usr/include/suitesparse/cholmod_partition.h
/usr/include/suitesparse/cholmod_supernodal.h
/usr/include/suitesparse/cholmod_template.h
/usr/include/suitesparse/colamd.h
/usr/include/suitesparse/cs.h
/usr/include/suitesparse/klu.h
/usr/include/suitesparse/klu_internal.h
/usr/include/suitesparse/klu_version.h
/usr/include/suitesparse/ldl.h
/usr/include/suitesparse/spqr.hpp
/usr/include/suitesparse/umfpack.h
/usr/include/suitesparse/umfpack_col_to_triplet.h
/usr/include/suitesparse/umfpack_defaults.h
/usr/include/suitesparse/umfpack_free_numeric.h
/usr/include/suitesparse/umfpack_free_symbolic.h
/usr/include/suitesparse/umfpack_get_determinant.h
/usr/include/suitesparse/umfpack_get_lunz.h
/usr/include/suitesparse/umfpack_get_numeric.h
/usr/include/suitesparse/umfpack_get_symbolic.h
/usr/include/suitesparse/umfpack_global.h
/usr/include/suitesparse/umfpack_load_numeric.h
/usr/include/suitesparse/umfpack_load_symbolic.h
/usr/include/suitesparse/umfpack_numeric.h
/usr/include/suitesparse/umfpack_qsymbolic.h
/usr/include/suitesparse/umfpack_report_control.h
/usr/include/suitesparse/umfpack_report_info.h
/usr/include/suitesparse/umfpack_report_matrix.h
/usr/include/suitesparse/umfpack_report_numeric.h
/usr/include/suitesparse/umfpack_report_perm.h
/usr/include/suitesparse/umfpack_report_status.h
/usr/include/suitesparse/umfpack_report_symbolic.h
/usr/include/suitesparse/umfpack_report_triplet.h
/usr/include/suitesparse/umfpack_report_vector.h
/usr/include/suitesparse/umfpack_save_numeric.h
/usr/include/suitesparse/umfpack_save_symbolic.h
/usr/include/suitesparse/umfpack_scale.h
/usr/include/suitesparse/umfpack_solve.h
/usr/include/suitesparse/umfpack_symbolic.h
/usr/include/suitesparse/umfpack_tictoc.h
/usr/include/suitesparse/umfpack_timer.h
/usr/include/suitesparse/umfpack_transpose.h
/usr/include/suitesparse/umfpack_triplet_to_col.h
/usr/include/suitesparse/umfpack_wsolve.h