Date: Wed, 2 Sep 2015 21:32:25 +0200 From: Kozlov Sergey <kozlov.sergey.404@gmail.com> To: freebsd-questions@freebsd.org Subject: Re: Jail causes host to reboot Message-ID: <55E74EC9.1060803@gmail.com> In-Reply-To: <CA%2BtpaK0Yh3KEcOtTXx0Aco1dGiGWCw=t0LYOnGVyrMo33BLzMw@mail.gmail.com> References: <55E6E26A.1040706@kulturflatrate.net> <CA%2BtpaK1UVW5in1JUfoKwZuO=_ACTHx_xCPy0zWO1_NL1s9Wzmw@mail.gmail.com> <55E704D4.2050607@kulturflatrate.net> <CA%2BtpaK0Yh3KEcOtTXx0Aco1dGiGWCw=t0LYOnGVyrMo33BLzMw@mail.gmail.com>
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Hello Anyways, any userspace program should not be able to crash the kernel, so if you don't use self-modified OS and you're sure that everything is ok with your hardware, you should really consider adding a bug to <https://bugs.freebsd.org/bugzilla/>; Regards, Sergey Kozlov On 02.09.2015 17:11, Adam Vande More wrote: > On Wed, Sep 2, 2015 at 9:16 AM, Niklaas Baudet von Gersdorff < > niklaas@kulturflatrate.net> wrote: > >> On 02/09/15 15:56, Adam Vande More wrote: >> >> Thanks for this clarification. >> >> So, in case someone is able to get access to a jail and causes a kernel >> panic, the person can compromise the entire host system? >> > Yes, depending on configuration. It's trivial to make a jail insecure. > The trick is to make a jail secure and fully functional for your needs. > > >> I doubt that it is possible but you saying "depending on configuration" >> brought up the following question: Is there a way to tell the host >> system to only shut down the jail (and maybe send an email to me) in >> case the jail causes a panic and not reboot the entire system? >> > The host and jails use the same kernel, so if there's a panic it all goes > down. A separate monitoring and alerting platform is the only reliable way > I know to get emails if something goes down. > > Am I right that the only way to prevent such failure is virtualising an >> entire operating system instead of using a jail? >> > Yes, but virtualizing is a loaded term. Some people don't consider jails > as virtualization. I do, at least from a certain point of view. > Especially now since independent FS's and network stacks can be involved. > Then you have types like container eg OpenVZ(there was FreeBSD version of > this floating around on 9.x, not sure what happened to it). The guest in > container's have independent kernels so the host would survive in my > original scenario. Same w/ other virtualization types like KVM, bhyve, > VBox, Xen, etc. > >
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