Hi, I am unable to understand how new_fdt->open_fds can be freed in __free_fdtable when its an unsigned long in files_struct ? Details: FUNCTION: dup_fd http://lxr.free-electrons.com/source/fs/file.c#L261 LINE : 282 : new_fdt->open_fds = newf->open_fds_init; files_struct : http://lxr.free-electrons.com/source/include/linux/fdtable.h#L45 unsigned long open_fds_init[1]; Cheers, Pavi