Date: Mon, 9 Jul 2012 06:07:05 +0000 From: "Bjoern A. Zeeb" <bzeeb-lists@lists.zabbadoz.net> To: Mikolaj Golub <trociny@freebsd.org> Cc: d@delphij.net, FreeBSD virtualization mailing list <freebsd-virtualization@FreeBSD.org> Subject: Re: GPF when doing jail -r, possibly an use-after-free Message-ID: <A8594672-5F62-4809-BBE7-7C2C3FAFE3C3@lists.zabbadoz.net> In-Reply-To: <86liit8ocs.fsf@in138.ua3> References: <4FF32FC4.6020701@delphij.net> <86wr2kau38.fsf@in138.ua3> <4FF5E87C.2020908@delphij.net> <86r4sqasrt.fsf@kopusha.home.net> <672D93D3-D4B1-432E-AE53-98E6C05B8BE4@lists.zabbadoz.net> <86zk7da10y.fsf@in138.ua3> <E909B0C0-F4DE-4110-B151-98FAC9330B82@lists.zabbadoz.net> <86obnqq94x.fsf@kopusha.home.net> <50CFED43-7789-4F27-9EC7-85268B7F23D4@lists.zabbadoz.net> <86liit8ocs.fsf@in138.ua3>
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On 9. Jul 2012, at 06:01 , Mikolaj Golub wrote: > > On Sun, 8 Jul 2012 20:52:55 +0000 Bjoern A. Zeeb wrote: > > BAZ> Situation 1) > > BAZ> epairNa is in base, eiparNb is jail foo > BAZ> stop jail foo: jail -r foo > BAZ> both epairN[ab] will live in base and can be destiryed without vnet switching > > BAZ> Situation 2) > > BAZ> epairNa is in base, eiparNb is jail foo > BAZ> you are in jail foo and type epairNb destroy; that should not be allowed > > BAZ> Situation 3) > > BAZ> epairNa is in base, eiparNb is jail foo > BAZ> you are in base and type ifconfig epairNa destroy > > BAZ> This is your case ... I am not sure what I'd expect in this case, > BAZ> especailly given epair is special... You probably are right. > BAZ> Ideally I'd not allow it to be destroyed unless both are in the > BAZ> if_home_vnet. However it seems we allow this; so in that case > BAZ> I definitively make sure to use the CURVNET_SET_QUIET() version > BAZ> to avoid the expected noise otherwise. > > It looks like epair was expected to allow this, because in non-patched version > it already did switching before freeing the interface. It just did not switch > bere detaching. > > CURVNET_SET_QUIET() is used in the current version of the patch so I suppose I > can commit it. > > But if you think that just not allowing to destroy unless both ends are in the > f_home_vnet is a preferred solution and it is not late to change this I can > provide the patch. Get it in for now; it helps people. We should keep the other things in mind and write down a proper policy; it's more interesting as you can do other things with cloners you can create inside a vnet as well, today and later. > > BAZ> The moment cloners will handle this it'll all be centrally managed > BAZ> and individual device drivers shouldn't need to worry about it anymore. > > -- > Mikolaj Golub > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to "freebsd-virtualization-unsubscribe@freebsd.org" -- Bjoern A. Zeeb You have to have visions! It does not matter how good you are. It matters what good you do!home | help
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