Re: [06/07] [PATCH] SCSI tape security: require CAP_ADMIN forSG_IO etc.

From: Arjan van de Ven
Date: Fri Apr 29 2005 - 04:52:05 EST

On Thu, 2005-04-28 at 08:43 +0300, Kai Makisara wrote:
> On Wed, 27 Apr 2005, Alan Cox wrote:
> > On Mer, 2005-04-27 at 18:16, Greg KH wrote:
> > > -stable review patch. If anyone has any objections, please let us know.
> >
> > This patch is just wrong on so many different levels its hard to know
> > where to begin.
> >
> > 1. The auth for arbitary commands is CAP_SYS_RAWIO
> Valid complaint.
> > 2. "The SCSI command permissions were discussed widely on the linux
> > lists but this did not result in any useful refinement of the
> > permissions." - this is false. The process was refined, a table setup
> > was added and debugged.
> Any user having write access to the device is still allowed to send MODE
> SELECT (and some other commands useful for CD/DVD writers but being
> potentially dangerous to other).

If you give your user *WRITE ACCESS* to the tape you expect him to be
able to do a lot of writing, right? The restrictions for *READ* are
obviously more clear...

> OK. If the Linux solution to these kind of security problems in the not so
> central areas of kernel is to wait and see if the problem disappears
> without any action, I have to accept that. But I have tried...

the security problem is giving someone write access to a device and then
somehow expect that to mean "selective write" ?

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