Providing it is the same file system supported by both hosts, it may work, but I don't think it is recommended.
When you create a LUN you need to declare its multiprotocol type & it is different for both OSes: "hpux" & "linux" respectively.
LUN Multiprotocol Type
The LUN Multiprotcol Type, or operating system type, specifies the OS of the host accessing the LUN. It also determines the layout of data on the LUN, the geometry used to access that data, and the minimum and maximum size of the LUN.
Re: Can a mapped NetApp iscsi lun to HPUX host be remaped to a Linux host?