Messages in this thread | | | Date | Fri, 12 Jan 2007 09:17:06 -0500 | From | Shaya Potter <> | Subject | Re: unionfs unusable on multiuser systems (was Re: [PATCH 01/24] Unionfs: Documentation) |
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Pavel Machek wrote: > Hi! > >>>> That statement is meant to scare people away from modifying the lower fs :) >>>> I tortured unionfs quite a bit, and it can oops but it takes some effort. >>> But isn't it then potential DOS? If you happen to union two filesystems >>> and an untrusted user has write access to both original filesystem and >>> the union, then you say he'd be able to produce oops? That does not >>> sound very secure to me... And if any secure use of unionfs requires >>> limitting access to the original trees, then I think it's a good reason >>> to implement it in unionfs itself. Just my 2 cents. >> You mean somebody like, say, a perfectly innocent process working on the >> NFS server or some other client that is oblivious to the existence of >> unionfs stacks on your particular machine? >> To me, this has always sounded like a showstopper for using unionfs with >> a remote filesystem. > > Actually, it is worse than that. find / (and updatedb) *will* write to > all the filesystems (atime). > > Expecting sysadmins to know/prevent this seems like expecting quite a > lot from them. Sounds like a show stopper to me :-(....
a modified atime will not affect unionfs at all (at least from my experience) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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