Re: [PATCH][2.4] cleanup ptrace secfix and fix most side effects

[Alan Cox]

On Iau, 2003-05-08 at 22:31, Alan Cox wrote:
> > Using is_dumpable() here is not neccesary because the checks done here are:
> > 
> > >        if (!(child->ptrace & PT_PTRACED))
> > >                return -ESRCH;
> 
> Except that current->mm->dumpable is not per task but per mm so you
> might ptrace one thread and have another go setuid.

Thinking about this harder

A ptraced thread cannot go setuid since we don't permit the exec to do
it

A setuid thread marks the mm dumpable so no thread can be ptraced (since
all threads inheriting the mm inherit it from the exec)

So ignore my earlier message