On Tue, Dec 6, 2016 at 10:25 PM, Miklos Szeredi <miklos@xxxxxxxxxx> wrote: > On Tue, Dec 6, 2016 at 10:13 PM, Jeremy Allison <jra@xxxxxxxxx> wrote: >> On Tue, Dec 06, 2016 at 03:15:29PM -0500, J. Bruce Fields wrote: >>> On Fri, Dec 02, 2016 at 10:57:42AM +0100, Miklos Szeredi wrote: >>> > On Tue, Oct 11, 2016 at 2:50 PM, Andreas Gruenbacher >>> > <agruenba@xxxxxxxxxx> wrote: >>> > > Normally, deleting a file requires MAY_WRITE access to the parent >>> > > directory. With richacls, a file may be deleted with MAY_DELETE_CHILD access >>> > > to the parent directory or with MAY_DELETE_SELF access to the file. >>> > > >>> > > To support that, pass the MAY_DELETE_CHILD mask flag to inode_permission() >>> > > when checking for delete access inside a directory, and MAY_DELETE_SELF >>> > > when checking for delete access to a file itself. >>> > > >>> > > The MAY_DELETE_SELF permission overrides the sticky directory check. >>> > >>> > And MAY_DELETE_SELF seems totally inappropriate to any kind of rename, >>> > since from the point of view of the inode we are not doing anything at >>> > all. The modifications are all in the parent(s), and that's where the >>> > permission checks need to be. >>> >>> I'm having a hard time finding an authoritative reference here (Samba >>> people might be able to help), but my understanding is that Windows >>> gives this a meaning something like "may I delete a link to this file". >>> >>> (And not even "may I delete the *last* link to this file", which might >>> also sound more logical.) >> >> I just did a recent patch here. In Samba we now check for >> SEC_DIR_ADD_FILE/SEC_DIR_ADD_SUBDIR on the target directory >> (depending on if the object being moved is a file or dir). > > And MAY_DELETE_SELF as well, for rename? That's really counterintuitive for me. Yes, MAY_DELETE_SELF applies to delete as well as rename; otherwise rename() would behave different from link() + unlink(); when a user has the appropriate permissions, the result should be the same though. Thanks, Andreas
