From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [Patch net] xt_RATEEST: acquire xt_rateest_mutex for hash insert Date: Wed, 31 Jan 2018 17:44:46 -0800 Message-ID: <1517449486.3715.112.camel@gmail.com> References: <20180201002631.17638-1-xiyou.wangcong@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netfilter-devel@vger.kernel.org, Pablo Neira Ayuso To: Cong Wang , netdev@vger.kernel.org Return-path: In-Reply-To: <20180201002631.17638-1-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org On Wed, 2018-01-31 at 16:26 -0800, Cong Wang wrote: > rateest_hash is supposed to be protected by xt_rateest_mutex. > > Reported-by: > Fixes: 5859034d7eb8 ("[NETFILTER]: x_tables: add RATEEST target") > Cc: Pablo Neira Ayuso > Signed-off-by: Cong Wang > --- > net/netfilter/xt_RATEEST.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c > index 498b54fd04d7..83ec3a282755 100644 > --- a/net/netfilter/xt_RATEEST.c > +++ b/net/netfilter/xt_RATEEST.c > @@ -36,7 +36,9 @@ static void xt_rateest_hash_insert(struct xt_rateest *est) > unsigned int h; > > h = xt_rateest_hash(est->name); > + mutex_lock(&xt_rateest_mutex); > hlist_add_head(&est->list, &rateest_hash[h]); > + mutex_unlock(&xt_rateest_mutex); > } We probably should make this module netns aware, otherwise bad things will happen. (It seems multiple threads could run, so getting the mutex twice (xt_rateest_lookup then xt_rateest_hash_insert() is racy)