RE: [Xen-users] Tracking DomU memory

["Ulrich Windl" <ulrich.windl@xxxxxxxxxxxxxxxxxxxx>]

On 9 Jan 2007 at 17:41, Security Initiative Team wrote:

> Is it possible for the "root" user of a guest domain to
> update the "text" section of a user-level process in that guest domain?
> 
> The text section is mapped as read-only,
> but is the "root" user privileged enough  to be able to
> update the page-table entry (which will go through Xen)
> to make it a writable mapping and then update it? 

Considering multiple CPUs this is an interesing concept just like 
self-modifying 
code...

Only a few things prevent root from writing to /dev/mem, commonsense is one of 
those, but you can read paswords from it, just as you can patch code (AFAIK).

Still: Why whould one want to do so?

Ulrich


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