From patchwork Mon Apr 17 11:02:40 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Davide Caratti X-Patchwork-Id: 13213703 X-Patchwork-Delegate: kuba@kernel.org 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 09D0EC77B72 for ; Mon, 17 Apr 2023 11:12:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231190AbjDQLMG (ORCPT ); Mon, 17 Apr 2023 07:12:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229559AbjDQLMF (ORCPT ); Mon, 17 Apr 2023 07:12:05 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 580AD6A78 for ; Mon, 17 Apr 2023 04:10:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681729740; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=JPjIm3Vq19KYZ2oEFTQUD3krJLjmBIkBqTeJ33Vqnrk=; b=FE0Aq1aA8HOFuE89asS3TWJyaoUDT10brjzx3lw/2wcvTV0erMdR2Xrr4SlNqB4+ivD2wf DHwAxwE1bO8I7gnQ7Gojz274Rzef5v0qXrozqnAhBZysy0BhjKqpv1Kyfb7jTxVzWeEm0w QLNbD0qMB5Zfa3sY9VYpIlA4xKCOMGg= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-504-XARlszbgOLCaPY3UiJ_vIA-1; Mon, 17 Apr 2023 07:02:50 -0400 X-MC-Unique: XARlszbgOLCaPY3UiJ_vIA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id A6D22101A54F; Mon, 17 Apr 2023 11:02:49 +0000 (UTC) Received: from dcaratti.users.ipa.redhat.com (unknown [10.45.226.11]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6350F1121315; Mon, 17 Apr 2023 11:02:48 +0000 (UTC) From: Davide Caratti To: Jamal Hadi Salim , Cong Wang , Jiri Pirko Cc: Eric Dumazet , Christoph Paasch , netdev@vger.kernel.org Subject: [PATCH net] net/sched: sch_fq: fix integer overflow of "credit" Date: Mon, 17 Apr 2023 13:02:40 +0200 Message-Id: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org if sch_fq is configured with "initial quantum" having values greater than INT_MAX, the first assignment of "credit" does signed integer overflow to a very negative value. In this situation, the syzkaller script provided by Cristoph triggers the CPU soft-lockup warning even with few sockets. It's not an infinite loop, but "credit" wasn't probably meant to be minus 2Gb for each new flow. Capping "initial quantum" to INT_MAX proved to fix the issue. Reported-by: Christoph Paasch Link: https://github.com/multipath-tcp/mptcp_net-next/issues/377 Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler") Signed-off-by: Davide Caratti Reviewed-by: Eric Dumazet --- net/sched/sch_fq.c | 12 ++++++++-- .../tc-testing/tc-tests/qdiscs/fq.json | 22 +++++++++++++++++++ 2 files changed, 32 insertions(+), 2 deletions(-) diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c index 48d14fb90ba0..12efbcfc2938 100644 --- a/net/sched/sch_fq.c +++ b/net/sched/sch_fq.c @@ -842,8 +842,16 @@ static int fq_change(struct Qdisc *sch, struct nlattr *opt, } } - if (tb[TCA_FQ_INITIAL_QUANTUM]) - q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]); + if (tb[TCA_FQ_INITIAL_QUANTUM]) { + u32 initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]); + + if (initial_quantum <= INT_MAX) { + q->initial_quantum = initial_quantum; + } else { + NL_SET_ERR_MSG_MOD(extack, "invalid initial quantum"); + err = -EINVAL; + } + } if (tb[TCA_FQ_FLOW_DEFAULT_RATE]) pr_warn_ratelimited("sch_fq: defrate %u ignored.\n", diff --git a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json index 8acb904d1419..3593fb8f79ad 100644 --- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json +++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json @@ -114,6 +114,28 @@ "$IP link del dev $DUMMY type dummy" ] }, + { + "id": "10f7", + "name": "Create FQ with invalid initial_quantum setting", + "category": [ + "qdisc", + "fq" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "$IP link add dev $DUMMY type dummy || /bin/true" + ], + "cmdUnderTest": "$TC qdisc add dev $DUMMY handle 1: root fq initial_quantum 0x80000000", + "expExitCode": "2", + "verifyCmd": "$TC qdisc show dev $DUMMY", + "matchPattern": "qdisc fq 1: root.*initial_quantum 2048Mb", + "matchCount": "0", + "teardown": [ + "$IP link del dev $DUMMY type dummy" + ] + }, { "id": "9398", "name": "Create FQ with maxrate setting",