From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Subject: Re: [PATCH net v2] ovs: add recursion limit to ovs_vport_receive Date: Fri, 15 Jan 2016 14:28:29 +0900 Message-ID: <20160115052825.GA20879@vergenet.net> References: <1452812755-14018-1-git-send-email-hannes@stressinduktion.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, dev@openvswitch.org, Pravin Shelar To: Hannes Frederic Sowa Return-path: Received: from mail-pa0-f50.google.com ([209.85.220.50]:34485 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750810AbcAOF2i (ORCPT ); Fri, 15 Jan 2016 00:28:38 -0500 Received: by mail-pa0-f50.google.com with SMTP id uo6so373748408pac.1 for ; Thu, 14 Jan 2016 21:28:38 -0800 (PST) Content-Disposition: inline In-Reply-To: <1452812755-14018-1-git-send-email-hannes@stressinduktion.org> Sender: netdev-owner@vger.kernel.org List-ID: Hi, On Fri, Jan 15, 2016 at 12:05:55AM +0100, Hannes Frederic Sowa wrote: > 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). > Thus add an extra recursion limit counter for ovs_vport_receive until > parts of the stack usage is moved to percpu scratch space. > > Cc: Pravin Shelar > Signed-off-by: Hannes Frederic Sowa Thanks for this. Its looks like a clean solution to a problem that has been on my todo list for quite some time. Reviewed-by: Simon Horman