From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6123C6FA86 for ; Tue, 6 Sep 2022 13:50:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238408AbiIFNu2 (ORCPT ); Tue, 6 Sep 2022 09:50:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238746AbiIFNsb (ORCPT ); Tue, 6 Sep 2022 09:48:31 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F2B41F62C; Tue, 6 Sep 2022 06:39:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 40B63B818CB; Tue, 6 Sep 2022 13:37:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82A7FC433D6; Tue, 6 Sep 2022 13:37:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1662471423; bh=wqumMZXi1LsOqk20M9uLwZVwJ/RaUHqGDItllRlXl3s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZWVvVkJUCc/L+LbChcYYZtbSTa8y9FbB++zjS9cb2XeSWlHiyn8NrFefgO0LIiF2q IbXenKwuzY6e8MpQCp3M2O+d7g5Li1x0aql0zMmEKugIgShSjpYqtaa0B1EK5DGr9U scPNngmB71/MSLsbppSIbS15K0KIHRFvS8JEI7F0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Zhengchao Shao , Paolo Abeni , Sasha Levin Subject: [PATCH 5.15 021/107] net: sched: tbf: dont call qdisc_put() while holding tree lock Date: Tue, 6 Sep 2022 15:30:02 +0200 Message-Id: <20220906132822.654023854@linuxfoundation.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220906132821.713989422@linuxfoundation.org> References: <20220906132821.713989422@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhengchao Shao [ Upstream commit b05972f01e7d30419987a1f221b5593668fd6448 ] The issue is the same to commit c2999f7fb05b ("net: sched: multiq: don't call qdisc_put() while holding tree lock"). Qdiscs call qdisc_put() while holding sch tree spinlock, which results sleeping-while-atomic BUG. Fixes: c266f64dbfa2 ("net: sched: protect block state with mutex") Signed-off-by: Zhengchao Shao Link: https://lore.kernel.org/r/20220826013930.340121-1-shaozhengchao@huawei.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- net/sched/sch_tbf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index 78e79029dc631..6eb17004a9e44 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -342,6 +342,7 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt, struct nlattr *tb[TCA_TBF_MAX + 1]; struct tc_tbf_qopt *qopt; struct Qdisc *child = NULL; + struct Qdisc *old = NULL; struct psched_ratecfg rate; struct psched_ratecfg peak; u64 max_size; @@ -433,7 +434,7 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt, sch_tree_lock(sch); if (child) { qdisc_tree_flush_backlog(q->qdisc); - qdisc_put(q->qdisc); + old = q->qdisc; q->qdisc = child; } q->limit = qopt->limit; @@ -453,6 +454,7 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt, memcpy(&q->peak, &peak, sizeof(struct psched_ratecfg)); sch_tree_unlock(sch); + qdisc_put(old); err = 0; tbf_offload_change(sch); -- 2.35.1