Re: SG_IO and security

Bill Davidsen
2004-08-16T22:24:02Z

Jeff Garzik wrote:
> Peter Jones wrote:
>
>> On Thu, 12 Aug 2004 22:22:36 +0300 (EEST), Kai Makisara
>> <kai.makisara@kolumbus.fi> wrote:
>>
>>> On Thu, 12 Aug 2004, Linus Torvalds wrote:
>>>
>>>> Let's see now:
>>>>
>>>> brw-rw---- 1 root disk 3, 0 Jan 30 2003 /dev/hda
>>>>
>>>> would you put people you don't trust with your disk in the "disk"
>>>> group?
>>>>
>>>
>>> This protects disks in practice but SG_IO is currently supported by
>>> other
>>> devices, at least SCSI tapes. It is reasonable in some organizations to
>>> give r/w access to ordinary users so that they can read/write tapes. I
>>> would be worried if this would enable the users, for instance, to
>>> mess up
>>> the mode page contents of the drive or change the firmware.
>>
>>
>>
>> Sure, but for that we need command based filtering.
>
>
> We have that now (sigh). See attached patch, which is in BK...
>
> A similar approach could be applied to tape as well.
>
> Though in general I think command-based filtering is not scalable... at
> the very least I would prefer a list loaded from userspace at boot.

It would seem that the list is unlikely to change much, since it would
presumably be limited to the standard SCSI commands, and require RAWIO
for vendor commands. Do you see any like change I'm missing?

--
-bill davidsen (davidsen@tmr.com)
"The secret to procrastination is to put things off until the
last possible moment - but no longer" -me