Subject: Re: MNT_NODEV and nullfs and derived filesystems
To: Manuel Bouyer <>
From: Bill Studenmund <>
List: tech-kern
Date: 03/17/1999 10:00:23
On Wed, 17 Mar 1999, Manuel Bouyer wrote:

> Hi,
> As pointed out to me by Artur Grabowski, there is a problem with nullfs
> and derived (umap, union): MNT_NODEV has to be checked at open(), which is not
> done for these filesystems (MNT_NODEV on the underlying filesystem is
> handled, however, so this is not really a problem as big as MNT_NOEXEC).
> Below is a patch that should fix this for null, umap, union (this was
> fixed some time ago in OpenBSD, but for nullfs only).
> In my sense this is more a semantic problem than a security problem.
> Comments ?

Looks good.

Take care,