Re: More duplicate code, vnode locking question

[Elad Efrat <elad%NetBSD.org@localhost>]

Matthew Mondor wrote:
> On Tue, 21 Apr 2009 00:25:32 +0300
> Elad Efrat <elad%NetBSD.org@localhost> wrote:
>
>
> >         int
> >         common_mount_allowed(kauth_cred_t cred, struct vnode *vp,
> >             bool vnode_locked, int mode)
> >         {
> >                 /* if root, always allow. */
> >                 ...
>
> I'm actually unsure if security level has to be taken into account at
> this layer, but if so, I just want to remind that even the superuser
> shouldn't be able to mount new file systems under security level >1,
> which still might imply a call to kauth in uid == 0 case so the 44bsd
> secmodel may enforce security level policy?

This is the file-system specific code. We check securelevel way before
that. See

        http://nxr.netbsd.org/source/xref/sys/kern/vfs_syscalls.c#295

and

http://nxr.netbsd.org/source/xref/sys/secmodel/securelevel/secmodel_securelevel.c#204

Thanks,

-e.