Re: Linux kernel exploit

[Stefan Roas <sroas () roath org>]

On Fri Dec 10, 2010 at 17:52:37, Wolf wrote:
> Well, I'm a first time writer to Bugtraq, but this is interesting. I
> commented out the call to clone(), and after it simply called
> trigger(fildes), and apparently, it works. Only tested on a stock
> install of Ubuntu 10.10, but I thought the bug was in clone()?

No, the bug is not checking address overwrite limit in the do_exit() path,
which migh offer the chance to overwrite an arbitrary memory location. The
clone call in the supplied poc just made sure do_exit() actually accesses
the memory clearing the child tid (using the CLONE_CHILD_CLEARTID). So if
your running process why so ever also had CLONE_CHILD_CLEARTID set it would
trigger the problem as well.