Ken Moffat wrote:
> On Sun, Apr 08, 2012 at 08:51:02PM -0500, Bruce Dubbs wrote:
>> Wayne Blaszczyk wrote:
>>> On 09/04/12 02:25, Bruce Dubbs wrote:
>>>> I do understand that some will be more comfortable with the tighter 
>>>> permissions just on principle, but I'm trying to understand why rw 
>>>> access to /dev/dri/card0 for a 'guest' user would be a problem.
>>> I'm not an expert hacker, so I would know how, but I could just imaging
>>> there being an exploit of sending the right combination of bytes to say
>>> hang the video driver.
>>> Just me being paranoid.
>> I understand what you are saying, but there are a lot of other cases. 
>> Virtually all tty interfaces are 666.  Also rtc and, in my case, 
>> nividia0 and nvidiactl.  It's curious that console is 622.
>>
>> Again, I have no problems with using the video group.  I was just 
>> suggesting a possible alternative.

>  Wayne has described the situation nicely - why open yourself to a
> possible exploit ?
> 
>  Looking at -my- /dev/tty*, on LFS-7.1 /dev/tty is 666, but nothing
> else.  The /dev/ttyN are 620 (tty0) or 600, /dev/ttyNN are 620,
> /dev/ttyXN are 660.  For me, /dev/rtc is 644.  I've never run nvidia
> binary drivers (I suspect they breach the kernel's licensing, and
> anyway the only nvidia card I had was on a ppc64 mac which they
> don't support), and I certainly wouldn't hold them up as paragons of
> how things ought to be.
> 
>  For me, /dev/console is 600.  Have you done something weird to
> change your permissions ?

Never mind.  I'm rambling.  The permissions were from an old system.  On 
the current system I only have write permissions to other on full, log 
(a socket), null, ptmx, random,  tty, urandom, and zero.

   -- Bruce
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