Re: reiserfs one user DoS?

viro
2003-10-06T02:14:16Z

On Sun, Oct 05, 2003 at 07:03:42PM -0700, Mike Fedyk wrote:
> On Mon, Oct 06, 2003 at 01:51:49AM +0200, Erik Tews wrote:
> > On Sun, Oct 05, 2003 at 06:09:24PM +0200, Christian Kujau wrote:
> > > Hans Reiser schrieb:
> > > >>I have found such strange thing:
> > > >>
> > > >>pseudo@avalon at 14:04:00 ~> dd if=/dev/zero of=file bs=1 count=0
> > > >>seek=1000000000000
> > > >>
> > > >>After that my Intel Celeron 800 MHz/384M RAM 60G/Seagate U6 under
> > > >>Linux-2.4.22-grsec on reiserfs was utilized 100% for more than 2 hours.
> > > >>dd process can't be killed.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

> > Really? If I got a process which is unkillable, how can the kernel kill
> > this process if it runs out of cpu-time?
>
> If it is unkillable, you're either talking about kernel bugs or NFS, and
> root should be able to kill a user process that has run out of ulimit
> resources.