Tati Chevron wrote: > On Tue, Dec 08, 2015 at 08:09:47AM -0700, Theo de Raadt wrote: > >> Currently, it's possible, (as root), to do something like: > >> > >> # mount_mfs -s 1g swap / > >> > >> which succeeds, and mounts the empty filesystem as the root filesystem. > >> > >> This makes the machine inoperable and requires a physical reset, without a > >> clean shutdown, as no system binaries are available. > >> > >> Shouldn't we make mount_mfs error out in this case? > > > >what is "this case"? > > mount_mfs as opposed to mount. > > It's possible to mount a regular filesystem on a mount point that is > already in use, except for /, which fails with an error. > > The behaviour of mount_mfs is inconsistent with that of mount, in > that it allows the root directory to be used as a mount point, whereas > mount does not.
This would have been interesting information to include in your original email. As far as I can see, there's no reason why mount and mount_mfs would behave differently here.
