From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:60068 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726051AbeKCEEA (ORCPT ); Sat, 3 Nov 2018 00:04:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Phil Sutter , Jiri Pirko , Eric Dumazet , "David S. Miller" Subject: [PATCH 4.14 136/143] net: sched: Fix for duplicate class dump Date: Fri, 2 Nov 2018 19:35:21 +0100 Message-Id: <20181102182908.626196713@linuxfoundation.org> In-Reply-To: <20181102182857.064326086@linuxfoundation.org> References: <20181102182857.064326086@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Phil Sutter [ Upstream commit 3c53ed8fef6881a864f0ee8240ed2793ef73ad0d ] When dumping classes by parent, kernel would return classes twice: | # tc qdisc add dev lo root prio | # tc class show dev lo | class prio 8001:1 parent 8001: | class prio 8001:2 parent 8001: | class prio 8001:3 parent 8001: | # tc class show dev lo parent 8001: | class prio 8001:1 parent 8001: | class prio 8001:2 parent 8001: | class prio 8001:3 parent 8001: | class prio 8001:1 parent 8001: | class prio 8001:2 parent 8001: | class prio 8001:3 parent 8001: This comes from qdisc_match_from_root() potentially returning the root qdisc itself if its handle matched. Though in that case, root's classes were already dumped a few lines above. Fixes: cb395b2010879 ("net: sched: optimize class dumps") Signed-off-by: Phil Sutter Reviewed-by: Jiri Pirko Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_api.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -1917,7 +1917,8 @@ static int tc_dump_tclass_root(struct Qd if (tcm->tcm_parent) { q = qdisc_match_from_root(root, TC_H_MAJ(tcm->tcm_parent)); - if (q && tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) + if (q && q != root && + tc_dump_tclass_qdisc(q, skb, tcm, cb, t_p, s_t) < 0) return -1; return 0; }