Date: Wed, 25 Aug 2021 13:50:04 UTC
firstname.lastname@example.org wrote: > https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=251046 > > --- Comment #15 from Anatoli <email@example.com> --- > Mark, All, > >> --- Comment #3 from Mark Johnston <markj@FreeBSD.org> --- >> PRIV_IO access is not required only by /dev/io, it is also required for >> sysarch(I386_SET_IOPERM), which is otherwise available to jailed processes. So >> the patch definitely should not be committed. A better solution would be to >> extend pci(4) so that bhyve can use it to do everything required for PCI >> passthrough. Even then I'm not sure why it's useful to jail the bhyve process >> - what does it buy you? > > In light of the recently patched VM-escape vulnerability in bhyve > (FreeBSD-SA-21:13.bhyve fixing the CVE-2021-29631), I'd like to highlight the > benefits of running bhyve under a non-root user and inside a jail by default. > > If it were the case, this vulnerability, instead of a complete host takeover > would just have a DoS impact on the malicious VM, which is perfectly fine IMO. > > That's why it's extremely important to make bhyve work correctly under all > situations (including PPT) inside jail so we could make it run inside jail by > default. > > >> --- Comment #8 from Mark Johnston <markj@FreeBSD.org> --- >> I am very skeptical that jailing bhyve with PCI passthrough enabled provides >> any meaningful security. /dev/pci allows a jailed root to access all PCI(e) >> devices in the system. Jails can be a useful deployment mechanism though, so I >> think we should better support their integration with bhyve. > > With respect to this, isn't it possible to restrict the bhyve process (maybe > self-restricting via Capsicum) to just the masked PCI addresses or to the PCI > addresses specified via the args so to limit the impact of a bhyve compromise > to > just the intended device(s)? > > Or, as you already proposed, to extend pci(4) so that bhyve can use it to do > everything required for PPT? > > Regards, > Anatoli > jail is not a vm.