On Mon, 29 Dec 2003, Paul Jakma wrote:
[...]
> > Is chmod of an in-use swapfile an important thing to be able to do?
>
> Had a box under memory pressure and had to add a swapfile to relieve
> said pressure. Noticed afterwards that it had been created under
> umask 0022 - not good, and the chmod to remove read rights for all
> blocked. Thankfully, it was my desktop, not a multiple user server :)
[...]
How much of the original problem goes away if swapon(8) were to refuse to
activate a file/device which has ownership/mode which it doesn't like?
Of course such a change to swapon(8) should be accompanied by a flag to
force swapping on a file/device with non-sane ownership/mode.
Regards,
Neale.
Neale Banks <[email protected]> wrote:
>
> How much of the original problem goes away if swapon(8) were to refuse to
> activate a file/device which has ownership/mode which it doesn't like?
I think swapon(8) should at least warn when the swapfile has inappropriate
permissions. It's an obvious and outright security hole.
On Thu, Jan 01, 2004 at 02:12:41AM -0800, Andrew Morton wrote:
> Neale Banks <[email protected]> wrote:
> >
> > How much of the original problem goes away if swapon(8) were to refuse to
> > activate a file/device which has ownership/mode which it doesn't like?
>
> I think swapon(8) should at least warn when the swapfile has inappropriate
> permissions. It's an obvious and outright security hole.
swapon had this warning for a while, but that generated lots of complaints.
Now this message is printed only when the -v (verbose) flag is given.
On Thu Jan 01, 2004 at 03:10:27PM +0100, Andries Brouwer wrote:
> On Thu, Jan 01, 2004 at 02:12:41AM -0800, Andrew Morton wrote:
> > Neale Banks <[email protected]> wrote:
> > >
> > > How much of the original problem goes away if swapon(8) were to refuse to
> > > activate a file/device which has ownership/mode which it doesn't like?
> >
> > I think swapon(8) should at least warn when the swapfile has inappropriate
> > permissions. It's an obvious and outright security hole.
>
> swapon had this warning for a while, but that generated lots of complaints.
> Now this message is printed only when the -v (verbose) flag is given.
Perhaps swapon should automagically do a chmod and chown on all
swapfiles, unless specifically asked to be wildly insecure
(perhaps with a -W option -- wildly insecure swapfile permissions
are considered acceptable)....
-Erik
--
Erik B. Andersen http://codepoet-consulting.com/
--This message was written using 73% post-consumer electrons--
On Thu, 1 Jan 2004, Erik Andersen wrote:
> Perhaps swapon should automagically do a chmod and chown on all
> swapfiles, unless specifically asked to be wildly insecure (perhaps
> with a -W option -- wildly insecure swapfile permissions are
> considered acceptable)....
There's no sane reason to have open swap files, so yes, above
behaviour would be good.
> -Erik
regards,
--
Paul Jakma [email protected] [email protected] Key ID: 64A2FF6A
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