Re: PATCH? fix unshare(NEWPID) && vfork()

From: Oleg Nesterov
Date: Mon Aug 19 2013 - 14:49:46 EST


On 08/19, Andy Lutomirski wrote:
>
> On Mon, Aug 19, 2013 at 11:33 AM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote:
> >
> > So do you think this change is fine or not (ignoring the fact it needs
> > cleanups) ?
>
> I think that removing the CLONE_VM check is fine (although there are
> some other ones that should probably be removed as well), but I'm not
> sure if that check needs replacing with something else.

OK, thanks... but I still can't understand.

The patch I sent is equivalent to the new one below. I just tried to
unify it with another check in do_fork().

Oleg.

--- x/kernel/fork.c
+++ x/kernel/fork.c
@@ -1176,7 +1176,7 @@ static struct task_struct *copy_process(
* If the new process will be in a different pid namespace
* don't allow the creation of threads.
*/
- if ((clone_flags & (CLONE_VM|CLONE_NEWPID)) &&
+ if ((clone_flags & (CLONE_THREAD | CLONE_PARENT | CLONE_NEWPID)) &&
(task_active_pid_ns(current) != current->nsproxy->pid_ns))
return ERR_PTR(-EINVAL);


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