Date: Thu, 4 Dec 2008 00:08:58 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Miquel van Smoorenburg <miquels@cistron.nl>
Cc: Geoffrey McRae <geoff@rabidhost.com>, Nick Andrew <nick@nick-andrew.net>,
       linux-kernel@vger.kernel.org
Subject: Re: New Security Features, Please Comment
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> Well, in this particular case, and with this API, perhaps not.

ptrace, patching your own binary, kill etc.

> It would be great if you could say 'limit setuid() to saved-uid + uids
> 1000-2000' or something like that.

For the fsuid

> If then the userlevel NFS server gets owned you can at least be sure
> none of the files in /bin have been modified ..

The userland nfsd uses fsuid.. thats important. Acting on behalf of
another user for file purposes does make sense. I can see a
"setfsuidlist()" call making sense too, but uid/euid/saved uid don't make
sense in this context.

Alan
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