From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net 1/1] net sched actions: fix dumping which requires several messages to user space Date: Tue, 27 Mar 2018 10:59:45 -0400 (EDT) Message-ID: <20180327.105945.563897120983885303.davem@davemloft.net> References: <1522090712-9154-1-git-send-email-cdillaba@mojatatu.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, kernel@mojatatu.com, jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us To: cdillaba@mojatatu.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:41074 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751068AbeC0O7r (ORCPT ); Tue, 27 Mar 2018 10:59:47 -0400 In-Reply-To: <1522090712-9154-1-git-send-email-cdillaba@mojatatu.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Craig Dillabaugh Date: Mon, 26 Mar 2018 14:58:32 -0400 > Fixes a bug in the tcf_dump_walker function that can cause some actions > to not be reported when dumping a large number of actions. This issue > became more aggrevated when cookies feature was added. In particular > this issue is manifest when large cookie values are assigned to the > actions and when enough actions are created that the resulting table > must be dumped in multiple batches. > > The number of actions returned in each batch is limited by the total > number of actions and the memory buffer size. With small cookies > the numeric limit is reached before the buffer size limit, which avoids > the code path triggering this bug. When large cookies are used buffer > fills before the numeric limit, and the erroneous code path is hit. > > For example after creating 32 csum actions with the cookie > aaaabbbbccccdddd ... > Note that the action with index 27 is omitted from the report. > > Fixes: 4b3550ef530c ("[NET_SCHED]: Use nla_nest_start/nla_nest_end")" > Signed-off-by: Craig Dillabaugh Applied and queued up for -stable.