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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7479C433E6 for ; Mon, 4 Jan 2021 16:00:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FA3922473 for ; Mon, 4 Jan 2021 16:00:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728158AbhADP76 (ORCPT ); Mon, 4 Jan 2021 10:59:58 -0500 Received: from mail.kernel.org ([198.145.29.99]:36514 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727434AbhADP74 (ORCPT ); Mon, 4 Jan 2021 10:59:56 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 603FB22597; Mon, 4 Jan 2021 15:59:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609775963; bh=QxzuUY0e0Cy6wxab/lpuSiUOCkFGDvGcK/xhVfGXaw4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y/iPaK60SMwRX8Lyqd5yFq6Rusd4IAGfwo2sEyu+s12qXzuBKJlwS3BEaSsm2TKeF QfA9rP2341guwY1ezqEh8HXgXh44F91HbR/P+/gAoTcR64obpgTdrGomkTVBRQ5uFe wVl9o+9/iYBWfKgg4xy9I7MPCWPlxVNFLsQXaDmo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+8971da381fb5a31f542d@syzkaller.appspotmail.com, Davide Caratti , Vinicius Costa Gomes , Jakub Kicinski Subject: [PATCH 5.4 01/47] net/sched: sch_taprio: reset child qdiscs before freeing them Date: Mon, 4 Jan 2021 16:57:00 +0100 Message-Id: <20210104155705.815222259@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210104155705.740576914@linuxfoundation.org> References: <20210104155705.740576914@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Davide Caratti [ Upstream commit 44d4775ca51805b376a8db5b34f650434a08e556 ] syzkaller shows that packets can still be dequeued while taprio_destroy() is running. Let sch_taprio use the reset() function to cancel the advance timer and drop all skbs from the child qdiscs. Fixes: 5a781ccbd19e ("tc: Add support for configuring the taprio scheduler") Link: https://syzkaller.appspot.com/bug?id=f362872379bf8f0017fb667c1ab158f2d1e764ae Reported-by: syzbot+8971da381fb5a31f542d@syzkaller.appspotmail.com Signed-off-by: Davide Caratti Acked-by: Vinicius Costa Gomes Link: https://lore.kernel.org/r/63b6d79b0e830ebb0283e020db4df3cdfdfb2b94.1608142843.git.dcaratti@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_taprio.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1597,6 +1597,21 @@ free_sched: return err; } +static void taprio_reset(struct Qdisc *sch) +{ + struct taprio_sched *q = qdisc_priv(sch); + struct net_device *dev = qdisc_dev(sch); + int i; + + hrtimer_cancel(&q->advance_timer); + if (q->qdiscs) { + for (i = 0; i < dev->num_tx_queues && q->qdiscs[i]; i++) + qdisc_reset(q->qdiscs[i]); + } + sch->qstats.backlog = 0; + sch->q.qlen = 0; +} + static void taprio_destroy(struct Qdisc *sch) { struct taprio_sched *q = qdisc_priv(sch); @@ -1607,7 +1622,6 @@ static void taprio_destroy(struct Qdisc list_del(&q->taprio_list); spin_unlock(&taprio_list_lock); - hrtimer_cancel(&q->advance_timer); taprio_disable_offload(dev, q, NULL); @@ -1954,6 +1968,7 @@ static struct Qdisc_ops taprio_qdisc_ops .init = taprio_init, .change = taprio_change, .destroy = taprio_destroy, + .reset = taprio_reset, .peek = taprio_peek, .dequeue = taprio_dequeue, .enqueue = taprio_enqueue,