On Fri, Jul 03, 2020 at 08:02:07AM +0200, Greg Kroah-Hartman wrote: > On Thu, Jul 02, 2020 at 04:26:35PM -0700, Kees Cook wrote: > > + sattr->battr.size = 3 /* "0x", "\n" */ + (BITS_PER_LONG / 4); > > They get a correct "size" value now, nice! Yeah, though I do have some concerns that switching to a bin attribute changes the userspace behavior a bit. With seq_file-based "show", we get a 4096 size, and seeking isn't possible (lseek to non-0 location will fail). With the raw "read", we get the right size, but lseek() is allowed (but I've got the "read" handler refuse reads starting from non-zero). When I reviewed[1] potential readers (elftutils, systemtap, kmod), they all seem to do normal things (fopen/fscanf/fclose), so I'm hoping this won't be a problem in practice. > Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Thanks! [1] https://codesearch.debian.net/search?q=%2Fsys%2Fmodule.*sections&literal=0 -- Kees Cook
