On Sun, May 16, 2010 at 03:11:56PM +0000, The Fungi wrote: > On Sat, May 15, 2010 at 02:34:57PM -0700, Russ Allbery wrote: > > That's a good idea. I'm not sure if all UNIX group systems allow > > one to ask how many users are a member of a particular group, but > > if there's a way to ask that question at least in those group > > systems that support it, the implementation should be fairly > > straightforward. > > This is racy, unfortunately (at least by itself). Consider a non-UPG > system which starts with one user... this check passes and files get > created with group write flagged. Later, subsequent users appear > sharing that same group and the default umask stops making new files > group-writeable, but the first user's original files are now able to > be modified by others (and then his account is immediately at risk > of being taken over by one of the new users without his knowledge). > > Of course, coupled with other checks like uname==gname, parsing > login.defs, et cetera, it could add an extra layer of assurance.
I'd call it an extra layer of assumptions. I already get the shivers just thinking about the kind of complexity that is invented here. Now it's sufficient to have a look in /etc/profile to *know* the umask that will be set. If that scheme were implemented, I'd have to read code, several files and query ldap, or whatever is used, to *assume* what umask might be set. Please don't do that. If non-UPG systems should be supported, keep the umask at 022 and let the admin edit a single line to change it, if this is needed and he knows it's a pure UPG system. Cheers, harry -- To UNSUBSCRIBE, email to debian-devel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100516205051.gc4...@sbs288.lan
