/usr/share/librecad/patterns/ is in librecad-data 1.0.2+nolibs-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/librecad/patterns/angle.dxf
/usr/share/librecad/patterns/ansi31.dxf
/usr/share/librecad/patterns/ar-b816.dxf
/usr/share/librecad/patterns/ar-b816c.dxf
/usr/share/librecad/patterns/ar-b88.dxf
/usr/share/librecad/patterns/ar-brelm.dxf
/usr/share/librecad/patterns/ar-brstd.dxf
/usr/share/librecad/patterns/ar-conc.dxf
/usr/share/librecad/patterns/ar-hbone.dxf
/usr/share/librecad/patterns/ar-parq1.dxf
/usr/share/librecad/patterns/ar-roof.dxf
/usr/share/librecad/patterns/ar-rshke.dxf
/usr/share/librecad/patterns/arcs.dxf
/usr/share/librecad/patterns/arcs_2.dxf
/usr/share/librecad/patterns/box.dxf
/usr/share/librecad/patterns/brick.dxf
/usr/share/librecad/patterns/brstone.dxf
/usr/share/librecad/patterns/clay.dxf
/usr/share/librecad/patterns/concrete.dxf
/usr/share/librecad/patterns/cross.dxf
/usr/share/librecad/patterns/daemon.dxf
/usr/share/librecad/patterns/dolmit.dxf
/usr/share/librecad/patterns/earth.dxf
/usr/share/librecad/patterns/escher.dxf
/usr/share/librecad/patterns/flex.dxf
/usr/share/librecad/patterns/grass.dxf
/usr/share/librecad/patterns/grass_b.dxf
/usr/share/librecad/patterns/hex.dxf
/usr/share/librecad/patterns/hexagon_a.dxf
/usr/share/librecad/patterns/hexagon_b.dxf
/usr/share/librecad/patterns/honeycomb.dxf
/usr/share/librecad/patterns/hound.dxf
/usr/share/librecad/patterns/iso03w100.dxf
/usr/share/librecad/patterns/iso03w100a.dxf
/usr/share/librecad/patterns/kerpele.dxf
/usr/share/librecad/patterns/misc01.dxf
/usr/share/librecad/patterns/misc02.dxf
/usr/share/librecad/patterns/misc03.dxf
/usr/share/librecad/patterns/paisley.dxf
/usr/share/librecad/patterns/pantagon_a.dxf
/usr/share/librecad/patterns/pantagon_b.dxf
/usr/share/librecad/patterns/plastic.dxf
/usr/share/librecad/patterns/sacncr.dxf
/usr/share/librecad/patterns/sand.dxf
/usr/share/librecad/patterns/square.dxf
/usr/share/librecad/patterns/triangle_a.dxf
/usr/share/librecad/patterns/triangle_b.dxf