On Wed, 9 Sep 2020, Al Viro wrote: > On Wed, Sep 09, 2020 at 09:19:11AM +0200, Mickaël Salaün wrote: > > > > On 08/09/2020 20:50, Al Viro wrote: > > > On Tue, Sep 08, 2020 at 09:59:53AM +0200, Mickaël Salaün wrote: > > >> Hi, > > >> > > >> This height patch series rework the previous O_MAYEXEC series by not > > >> adding a new flag to openat2(2) but to faccessat2(2) instead. As > > >> suggested, this enables to perform the access check on a file descriptor > > >> instead of on a file path (while opening it). This may require two > > >> checks (one on open and then with faccessat2) but it is a more generic > > >> approach [8]. > > > > > > Again, why is that folded into lookup/open/whatnot, rather than being > > > an operation applied to a file (e.g. O_PATH one)? > > > > > > > I don't understand your question. AT_INTERPRETED can and should be used > > with AT_EMPTY_PATH. The two checks I wrote about was for IMA. > > Once more, with feeling: don't hide that behind existing syscalls. > If you want to tell LSM have a look at given fs object in a special > way, *add* *a* *new* *system* *call* *for* *doing* *just* *that*. It's not just for LSM, though, and it has identical semantics from the caller's POV as faccessat(). -- James Morris <jmorris@xxxxxxxxx>
