Re: [PATCH] netfilter: account ebt_table_info to kmemcg

From: Florian Westphal
Date: Sat Dec 29 2018 - 04:52:34 EST


Michal Hocko <mhocko@xxxxxxxxxx> wrote:
> On Fri 28-12-18 17:55:24, Shakeel Butt wrote:
> > The [ip,ip6,arp]_tables use x_tables_info internally and the underlying
> > memory is already accounted to kmemcg. Do the same for ebtables. The
> > syzbot, by using setsockopt(EBT_SO_SET_ENTRIES), was able to OOM the
> > whole system from a restricted memcg, a potential DoS.
>
> What is the lifetime of these objects? Are they bound to any process?

No, they are not.
They are free'd only when userspace requests it or the netns is
destroyed.