Messages in this thread | | | From | (Harald Koenig) | Subject | Re: Proposal: restrict link(2) | Date | Wed, 11 Dec 1996 18:36:51 +0100 (MET) |
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> > > why is Joe Random Cracker allowed to make a hard link to /etc/passwd at all > > > (or to any other file not owed by him) ? > > Why not? The user can copy the file, so why shouldn't it be possible to > make a (hard or soft) link to the file. Or the user is _not_ allowed to > copy (=read) the file, but in that case the user can't read the link > either. The user doesn't gain any additional power by linking the file, > the permissible operations on the file are exactly the same as on the > original link (except, of course, the ability to unlink the file from the > directory it was linked to). > > Sorry, but I think this is a non-issue and a case of not understanding the > Unix file system semantics.
I think I'm very well understanding Unix file system semantics. maybe I should have asked "what's the real benefit or reason to allow..." or similar instead.
I can only see drawbacks in allowing this (same as that SYSV allowing Joe U. to change the owner of his own files to any other user) giving a number of problem and risks and no real use at all. which possible good application am I missing ?
> One point remains, though: By making a hard link to a file, Joe A. User > can make a file exist on a file system much longer than the owner of the > file might expect.
this is a major problem esp. if you're using quotas and even more if Jim B. has to pay for disk space (very expensive at the csd of your university:( and Joe A. keeps hard links of your files in his own directories...
also you can change access policies to files (and not only to a copy of the file) using hard links when access to the original directory isn't possible for user/group B but Joe U. creates a hard link to this file in a directory tree with different access rights...
Harald -- All SCSI disks will from now on ___ _____ be required to send an email notice 0--,| /OOOOOOO\ 24 hours prior to complete hardware failure! <_/ / /OOOOOOOOOOO\ \ \/OOOOOOOOOOOOOOO\ \ OOOOOOOOOOOOOOOOO|// Harald Koenig, \/\/\/\/\/\/\/\/\/ Inst.f.Theoret.Astrophysik // / \\ \ koenig@tat.physik.uni-tuebingen.de ^^^^^ ^^^^^
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