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Date:      Fri, 21 May 2004 12:45:57 +0300
From:      Alex Lyashkov <shadow@psoft.net>
To:        Pawel Jakub Dawidek <pjd@FreeBSD.org>
Cc:        Ruslan Ermilov <ru@FreeBSD.org>
Subject:   Re: Call for a hacker.... security.bsd.see_other_uids in jails only
Message-ID:  <1085132756.24958.68.camel@berloga.shadowland>
In-Reply-To: <20040521094119.GB845@darkness.comp.waw.pl>
References:  <20040520220145.GN4567@genius.tao.org.uk> <20040521080218.GY845@darkness.comp.waw.pl> <20040521090217.GB57989@ip.net.ua> <20040521094119.GB845@darkness.comp.waw.pl>

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=F7 =F0=D4=CE, 21.05.2004, =D7 12:41, Pawel Jakub Dawidek =D0=C9=DB=C5=D4:
> On Fri, May 21, 2004 at 12:02:17PM +0300, Ruslan Ermilov wrote:
> +> I like the idea of per-jail sysctl MIB trees, e.g.:
> +>=20
> +> jail.<JID>.security.bsd
> +>=20
> +> When jail gets created, the generic sysctl code would traverse
> +> the primary sysctl tree (excluding the jail. subtree), and copy
> +> and attach those that have some jail-related flag to the
> +> jail.<JID>. branch.
> +>=20
> +> Inside the jail, jail.<JID>.security.bsd branch would map to
> +> just security.bsd.
> +>=20
> +> The generic sysctl code, when it detects it's run within a
> +> jail, will find a sysctl node "foo.bar", and if it has a
> +> jail-clone flag set, will remap a query to jail.<JID>.foo.bar.
> +>=20
> +> Whether it's allowed to change a particular sysctl inside
> +> a jail is another matter.
>=20
> There are two main issues with our current sysctls implementation:
> 1. We cannot hide sysctls/sysctl-trees.
> 2. We're operating in most cases on integers.
>=20
> We can work on 1, but we can't hack 2 easly, we have to transform
> sysctls, that have to be treated on per-jail basics from SYSCTL_INT
> to SYSCTL_PROC and if so, I'm not sure what for do we need
> security.jail.<JID> trees then. We can implement them in the same
> way security.jail.jailed is impelemented (it shows different value
> outside a jail and different inside) and if we want to change it:
>=20
> 	# jexec <JID> /sbin/sysctl <some_sysctl>=3D<some_value>
>=20
> Of course, there could be no /sbin/sysctl utility inside a jail,
> but I'll still suggest to add '-j' option to sysctl command to
> work just like 'killall -j' (i.e. jail_attach(<JID>); sysctl();).
killall -j =3D bad idea..
It not kill fork bomb started inside jail.
for protect from this situations me must have jail command for stop jail
and kill all tasks inside.

--=20
Alex Lyashkov <shadow@psoft.net>
PSoft



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