Re: [PATCH] Ext2FS: SUID on Dir

["Albert D. Cahalan" <acahalan@cs.uml.edu>]

Clifford Wolf writes:

> As you all know, on Ext2FS Partitions the SGID flag has a special function
> on directories: files within that directories will be owned by the same
> group that also owns the directory - which is useful for creating
> directories which are shared between the members of a group.
>
> But that only makes sense if the umask is set to give full permissions to
> the group (e.g. 007 or 002). Noone would do that if there is a system-wide
> 'users' group - so some distributions add an extra group for every user
> which lets the /etc/group file grow very fast and makes the admins life
> harder ...
>
> The following small patch adds a function to the SUID flag on directories.
> If the SUID flag is set for a diectory, all new files in that directory
> will get the same rights in the group-field as they have in their
> user-field.  So, if one sets both - SUID and SGID - on a directory, it
> will also work with a umask like 022 or 077 and there is no more need for
> an extra group for every user.

It would at least be more logical to have SUID do for user IDs
what SGID does for group IDs. Having SUID muck with group IDs
is pretty ugly.