Re: [uml-user] Security

2006-08-02 Thread Frank v Waveren
On Wed, Aug 02, 2006 at 02:15:39PM -0400, Jeff Dike wrote: > On Wed, Aug 02, 2006 at 10:35:20AM -0700, Jim Carter wrote: > > untrustedProg cannot use legitimate means to induce UML1's kernel to map > > kernel memory (except according to the UNIX file permissions of /dev/kmem). > > And whether /de

Re: [uml-user] Security

2006-08-02 Thread Jeff Dike
On Wed, Aug 02, 2006 at 10:35:20AM -0700, Jim Carter wrote: > untrustedProg cannot use legitimate means to induce UML1's kernel to map > kernel memory (except according to the UNIX file permissions of /dev/kmem). And whether /dev/kmem allows writing. This has been controversial in the past (and

Re: [uml-user] Security

2006-08-02 Thread Jim Carter
On Tue, 1 Aug 2006, TongKe Xue wrote: > Original Belief: I can use UML as a virtual machine; jail untrusted > processes. > > Let's say I am a user U, on a machine M running Linux. > I run an instance, UML1 of User Mode Linux. > Within this instance of UML1, I create a new user "jailedUser". > "j

Re: [uml-user] Security

2006-08-01 Thread Jeff Dike
On Tue, Aug 01, 2006 at 12:51:44AM -0700, TongKe Xue wrote: > Now, we know that M is running in ring 0. > UML1 is running as a process, so it's in ring 3. > > If this is the case, what protects "untrustedProg" from playing around > with the kernel memory of UML1? The process can't form a UML ker

Re: [uml-user] Security

2006-08-01 Thread Anselm Lingnau
TongKe Xue wrote: > Now, we know that M is running in ring 0. > UML1 is running as a process, so it's in ring 3. > > If this is the case, what protects "untrustedProg" from playing around > with the kernel memory of UML1? If you're running UML in SKAS mode (as you should), then »untrustedProg« do

[uml-user] Security

2006-08-01 Thread TongKe Xue
Please enlighten me of my ignorance. Original Belief: I can use UML as a virtual machine; jail untrusted processes. Problem: Let's say I am a user U, on a machine M running Linux. I run an instance, UML1 of User Mode Linux. Within this instance of UML1, I create a new user "jailedUser". "jai