From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net 0/4] net/sched: forbid 'goto_chain' on fallback actions Date: Mon, 22 Oct 2018 19:43:14 -0700 (PDT) Message-ID: <20181022.194314.1462566480309700181.davem@davemloft.net> References: Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: jiri@resnulli.us, xiyou.wangcong@gmail.com, jhs@mojatatu.com, netdev@vger.kernel.org To: dcaratti@redhat.com Return-path: Received: from shards.monkeyblade.net ([23.128.96.9]:40012 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726894AbeJWLEc (ORCPT ); Tue, 23 Oct 2018 07:04:32 -0400 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Davide Caratti Date: Sat, 20 Oct 2018 23:33:06 +0200 > the following command: > > # tc actions add action police rate 1mbit burst 1k conform-exceed \ > > pass / goto chain 42 > > generates a NULL pointer dereference when packets exceed the configured > rate. Similarly, the following command: > > # tc actions add action pass random determ goto chain 42 2 > > makes the kernel crash with NULL dereference when the first packet does > not match the 'pass' action. > > gact and police allow users to specify a fallback control action, that is > stored in the action private data. 'goto chain x' never worked for these > cases, since a->goto_chain handle was never initialized. There is only one > goto_chain handle per TC action, and it is designed to be non-NULL only if > tcf_action contains a 'goto chain' command. So, let's forbid 'goto chain' > on fallback actions. > > Patch 1/4 and 2/4 change the .init() functions of police and gact, to let > them return an error when users try to set 'goto chain x' in the fallback > action. Patch 3/4 and 4/4 add TDC selftest coverage to this new behavior. Series applied.