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Date: Mon, 16 Feb 2004 16:53:15 +0100
From: Pawel Jakub Dawidek <pjd@FreeBSD.org>
To: Maxim Konovalov <maxim@macomnet.ru>
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Subject: Re: Jails that keep hanging around
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On Mon, Feb 16, 2004 at 06:12:18PM +0300, Maxim Konovalov wrote:
+> > +> What I really do not understand why we do not leak in non-jail
+> > +> environment?
+> >
+> > I'm sure we are, this is just hard to check, because we don't have
+> > list with allocated 'cred' structures.
+> >
+> > But try to do your test without a jail and track 2nd column in:
+> >
+> > 	# sysctl kern.malloc | grep cred
+> >
+> > Number of objects grows when I'm killing daemon while connection
+> > exists. I'm wondering if this cannot be used to some DoS attack.
+>=20
+> Can't reproduce:
+>=20
+> $ vmstat -m | grep cred
+>          cred    38     5K      5K    22714  128
+>=20
+> [ serveral nc & telnet tests I port early in non-jail environment ]
+>=20
+> $ vmstat -m | grep cred
+>          cred    38     5K      5K    22833  128

Probably, because no new cred structure is allocated when you run 'nc'
without a jail (only this one used by your shell is referenced again).

Try to do:

	# su - <some_user> -c "/usr/local/bin/nc -p 1234 -l 127.0.0.1"

--=20
Pawel Jakub Dawidek                       http://www.FreeBSD.org
pjd@FreeBSD.org                           http://garage.freebsd.pl
FreeBSD committer                         Am I Evil? Yes, I Am!

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