Fwd: Re: need help with an rsync patch

Sherin A sherinmon at gmail.com
Tue Aug 13 09:34:40 MDT 2013

On Tuesday 13 August 2013 08:56 PM, Matthias Schniedermeyer wrote:
> On 13.08.2013 20:44, Sherin A wrote:
>> On Tuesday 13 August 2013 05:50 PM, Paul Slootman wrote:
>>> On Tue 13 Aug 2013, Matthias Schniedermeyer wrote:
>>>> BUT there is no direct vulnerability in that, only processes after that
>>>> (like backup/rsync) can make a vulnerability out of it.
>>> ... which is what I already wrote.
>>> Paul
>> So the solutions is to upgrade the kernel to 3.6  in all Operating
>> systems installations. ?  If it is one server  , then it  was a
>> solution.  Is it possible to add a flag to exclude hard inks of
>> regular file instead of waiting the OS vendors for updating there
>> kernel  to 3.6
> The other solution, if possible, is using separate
> root/data(/whatever)-fileystems.
> As hardlinks only work inside a single filesystem, if you can
> separate different things you significantly reduce the problematic
> cases.
> The described "problem" with /etc/shadow can be prevented by that, if
> the file isn't on the same filesytem, it can't be hardlinked.
> The advantage of this solution is that it workes for (all) older
> kernels.
=== Bum  again the third post =======

Thanks for your reply . But  think about the real world users. There  is 
not always necessary the /home will be  in separate disk partition or   
/tmp , /var/tmp , /usr/tmp.  Think about an openvz vps or disk with 
everything  on / (most of the cloud servers) . Rsync is  using  in a lot 
of production servers as a better tool for file backups. As in the case 
of a hosting server , we can't always trust all hosting users in  a 
single server.  Also just ignore the shadow  and  let us say there are 
two user on /home/foo and /home/fun  and the user fun created a hardlink 
to /hom/foo/joomla/configuration.php  , which contains database 
information of user foo's joomla site .    May be  this user created   
this type hardlinks with all the  directories  and files inside /home . 
So simply requesting a restore  will revert  the files into his readable 
form and he can wipe out every thing

  Thank you  Matthias for looking into it, awaiting for further updates.

Sherin A

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