Re: What does tainting actually mean?

[Nigel Cunningham]

Hi.

On Wed, 28 Apr 2004 01:19:32 -0400, Chris Friesen  
<cfriesen@xxxxxxxxxxxxxxxxxx> wrote:
> If only it were that easy.
>
> There has already been a case mentioned of a binary module that messed  
> up something that was only visible once that module was unloaded and  
> another one loaded.  It all depends totally on usage patterns.

I don't know what module you're talking about, but surely there must be  
something that could be done kernel-side to protect against such problems.  
Reference counting or such like? I guess if it was a hardware issue, but  
then again that might be an issue with too many assumptions being made  
about prior state? Maybe I am being too naive :>

> Binary modules, on the other hand, are often loaded up by users that  
> know just barely enough to download them and run an install script.  In  
> this case, it can be helpful to know up front that there has been  
> proprietary code running in kernel space, and aside from calls to kernel  
> APIs, we have no clue what else it was doing, what memory was being  
> trampled, what cpu registers were whacked, etc.

Now I see your point. Of course my previous point about patches is still  
valid though: the tainted flag only gives part of the picture. The person  
reporting the bug might create just as much of a black box for us by  
forgetting to mention that they applied patch foobar.

Regards,

Nigel
--
Nigel Cunningham
C/- Westminster Presbyterian Church Belconnen
61 Templeton Street, Cook, ACT 2614, Australia.
+61 (2) 6251 7727 (wk)
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