User: Password:
|
|
Subscribe / Log in / New account

Shared subtrees

Shared subtrees

Posted Nov 10, 2005 11:34 UTC (Thu) by nix (subscriber, #2304)
Parent article: Shared subtrees

One thing that might be useful here is a modification to mount(1) that allows the mounting of filesystems of specific types (listed in /etc/user-mountable-filesystems?) by any user *on top of any directory that user has write access to*. (I'm slightly concerned about /tmp, but not very. /tmp should probably be remounted separately in each user's subtree in any case in a system making use of this patch.)


(Log in to post comments)

Shared subtrees

Posted Nov 10, 2005 14:58 UTC (Thu) by jzbiciak (subscriber, #5246) [Link]

How about "any directory the user owns, or has write access to but does not have the sticky bit set"? Quick refresher on the sticky bit from the chmod(1) manpage:
STICKY DIRECTORIES
       When  the sticky bit is set on a directory, files in that directory may
       be unlinked or renamed only by root or their owner.  Without the sticky
       bit,  anyone able to write to the directory can delete or rename files.
       The sticky bit is commonly found on directories, such as /tmp, that are
       world-writable.

Shared subtrees

Posted Nov 11, 2005 11:05 UTC (Fri) by nix (subscriber, #2304) [Link]

Yes; that would mean that only world-writable directories (which strike me as a really bad idea) would be `problematic'.

(And for those of us giving each user their own /tmp, well, we can turn the sticky bit off and fix up the permissions so that only that user can write to it :) )

Shared subtrees

Posted Nov 12, 2005 0:06 UTC (Sat) by elanthis (guest, #6227) [Link]

If the rule is "any directory the user *owns*" then world-writable directories wouldn't be a big problem.

Shared subtrees

Posted Nov 26, 2005 6:14 UTC (Sat) by csamuel (✭ supporter ✭, #2624) [Link]

DEC Ultrix did allow users to do NFS mounts onto directories that they
owned. Whether this is a bug or a feature is left as an exercise for the
reader.

Shared subtrees

Posted Jan 4, 2006 4:23 UTC (Wed) by abartlet (subscriber, #3928) [Link]

Closer to home, this is also the behaviour of smbmount, when the helper binary (smbmnt) is setuid.


Copyright © 2017, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds