From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net v5] ovs: limit ovs recursions in ovs_execute_actions to not corrupt stack Date: Mon, 18 Jan 2016 12:10:18 -0500 (EST) Message-ID: <20160118.121018.2292058052018055331.davem@davemloft.net> References: <1453136628-9816-1-git-send-email-hannes@stressinduktion.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, pshelar@ovn.org, simon.horman@netronome.com, eric.dumazet@gmail.com To: hannes@stressinduktion.org Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:40640 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755829AbcARRKU (ORCPT ); Mon, 18 Jan 2016 12:10:20 -0500 In-Reply-To: <1453136628-9816-1-git-send-email-hannes@stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Hannes Frederic Sowa Date: Mon, 18 Jan 2016 18:03:48 +0100 > It was seen that defective configurations of openvswitch could overwrite > the STACK_END_MAGIC and cause a hard crash of the kernel because of too > many recursions within ovs. > > This problem arises due to the high stack usage of openvswitch. The rest > of the kernel is fine with the current limit of 10 (RECURSION_LIMIT). > > We use the already existing recursion counter in ovs_execute_actions to > implement an upper bound of 5 recursions. > > Cc: Pravin Shelar > Cc: Simon Horman > Cc: Eric Dumazet > Cc: Simon Horman > Signed-off-by: Hannes Frederic Sowa Applied, thanks Hannes.