On Fri, Jan 31, 2014 at 06:28:27PM -0700, James Gritton wrote: | On 1/31/2014 2:30 PM, Alexander Leidinger wrote: | > On Fri, 31 Jan 2014 12:34:48 +0000 (GMT) | > Robert Watson <rwat...@freebsd.org> wrote: | >> On Wed, 29 Jan 2014, Alexander Leidinger wrote: | >>>> It does. I included a warning in jail.8 that this will pretty | >>>> much undo jail security. There are still reasons some may want to | >>>> do this, but it's definitely not for everyone or even most people. | >>> | >>> It only "unjails" (= basically the same security level as the | >>> jail-host with the added benefit of the flexibility of a jail like | >>> easy moving from one system to another) the jail which has this | >>> flag set. All other jails without the flag can not "escape" to the | >>> host. | >>> | >>> I also have to add that just setting this flag does not give access | >>> to the host, you also have to configure a non-default devfs rule | >>> for this jail (to have the devices appear in the jail). | >> | >> This is not correct: devices do not need to be delegated in devfs for | >> PRIV_IO to allow bypass of the Jail security model, due to sysarch() | >> and the Linux-emulated equivalent, which turn out direct I/O access | >> from a user process without use of a device node. | > | > Ok, then it is just the non-default flag, not the additional devfs part. | > | > I agree with your other post that we are better of to document better | > what it means if an admin allows kmem access for a specific jail. | | I second the documentation route. Yes, it's true that this option | makes a totally insecure jail - at least one lacking the expected jail | security additions. But I think that while security is one of the | primary purposes of jails, it's not the only purpose. It should be | possible to have a trusted "master jail" that still takes advantage of | the encapsulation while allowing otherwise unsupported features such | as a desktop. | | The distinction of whether certain devices are required to break out | of a jail with allow.kmem is something of a red herring - the fact is | that anyone who wants this level of access is going to have the | devices in place anyway. | | I suppose "obviate" wasn't the best word for the situation. Maybe | something that starts with "WARNING: ..." is in order.
It's unfortunate that vimage requires jail. I want to use vimage but not have the security restrictions of a jail. To do this I patched jail to basically let everything through. It would be nice to be able to run jail in an insecure mode which I understand is a contradition. I do use the jail infrastructure to set the uname*/getosreldate so that a specific jail thinks it is FreeBSD version blah. Then I can ssh into that jail and pkg_add things, make ports etc. I use this on my laptop running current on the base. My other jails run various versions of FreeBSD. I don't care about security in this case. Thanks, Doug A. _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
