From: John Fastabend Subject: [net PATCH v2] net: sched: lock imbalance in hhf qdisc Date: Thu, 01 May 2014 09:23:06 -0700 Message-ID: <20140501162300.17183.83124.stgit@nitbit.x32> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, edumazet@google.com, vtlam@google.com To: eric.dumazet@gmail.com Return-path: Received: from mail-oa0-f41.google.com ([209.85.219.41]:41343 "EHLO mail-oa0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750993AbaEAQXU (ORCPT ); Thu, 1 May 2014 12:23:20 -0400 Received: by mail-oa0-f41.google.com with SMTP id m1so1299792oag.0 for ; Thu, 01 May 2014 09:23:20 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: hhf_change() takes the sch_tree_lock and releases it but misses the error cases. Fix the missed case here. To reproduce try a command like this, # tc qdisc change dev p3p2 root hhf quantum 40960 non_hh_weight 300000 Signed-off-by: John Fastabend --- net/sched/sch_hhf.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/sched/sch_hhf.c b/net/sched/sch_hhf.c index edee03d..6e957c3 100644 --- a/net/sched/sch_hhf.c +++ b/net/sched/sch_hhf.c @@ -553,11 +553,6 @@ static int hhf_change(struct Qdisc *sch, struct nlattr *opt) if (err < 0) return err; - sch_tree_lock(sch); - - if (tb[TCA_HHF_BACKLOG_LIMIT]) - sch->limit = nla_get_u32(tb[TCA_HHF_BACKLOG_LIMIT]); - if (tb[TCA_HHF_QUANTUM]) new_quantum = nla_get_u32(tb[TCA_HHF_QUANTUM]); @@ -567,6 +562,12 @@ static int hhf_change(struct Qdisc *sch, struct nlattr *opt) non_hh_quantum = (u64)new_quantum * new_hhf_non_hh_weight; if (non_hh_quantum > INT_MAX) return -EINVAL; + + sch_tree_lock(sch); + + if (tb[TCA_HHF_BACKLOG_LIMIT]) + sch->limit = nla_get_u32(tb[TCA_HHF_BACKLOG_LIMIT]); + q->quantum = new_quantum; q->hhf_non_hh_weight = new_hhf_non_hh_weight;