From patchwork Sat Jan 11 09:50:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 234156 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, 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 44810C33C9E for ; Sat, 11 Jan 2020 10:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A5D52084D for ; Sat, 11 Jan 2020 10:06:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578737176; bh=RriJfyQO+dMF4xwB9ajO0E4R54j6o4aGYeu+fFPkl9A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=OCreOu98YpEJEyzMPfjJx3yqn3hiEpO+DDG0pkQN7KuDlmTy6Osl4g7890WIx3yYJ KfsGAOe2wmMyn0/GfiiOQ6m7I3eKSJBBcIreeAOX9osbx9lamLteaS4g6miY75l52j 1rFDmq2bsitzVpSv7BlC/2g2uADNBeu+7TMCWdVg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729419AbgAKKGP (ORCPT ); Sat, 11 Jan 2020 05:06:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:40058 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729007AbgAKKGP (ORCPT ); Sat, 11 Jan 2020 05:06:15 -0500 Received: from localhost (unknown [62.119.166.9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0DFBC20848; Sat, 11 Jan 2020 10:06:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578737174; bh=RriJfyQO+dMF4xwB9ajO0E4R54j6o4aGYeu+fFPkl9A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xyXr8I1+haDEJebGC0c/U3SQ3XFa0z2WqePZSsE7vXbNcZtjqjw9SXsLKwZBuJno7 V16S35Xp4zCbw5lMWQl+dIrzgjZf/qlDMrfkDtQyv+3BrNxl5zUWnStfZEAeTU7kK7 6pq8XeVw+h1s/acbKAACWlpvYfm52ssDBXYTfkAI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , syzbot+dc9071cc5a85950bdfce@syzkaller.appspotmail.com, "David S. Miller" , Florian Westphal Subject: [PATCH 4.9 83/91] pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM Date: Sat, 11 Jan 2020 10:50:16 +0100 Message-Id: <20200111094912.594229733@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200111094844.748507863@linuxfoundation.org> References: <20200111094844.748507863@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Dumazet [ Upstream commit d9e15a2733067c9328fb56d98fe8e574fa19ec31 ] As diagnosed by Florian : If TCA_FQ_QUANTUM is set to 0x80000000, fq_deueue() can loop forever in : if (f->credit <= 0) { f->credit += q->quantum; goto begin; } ... because f->credit is either 0 or -2147483648. Let's limit TCA_FQ_QUANTUM to no more than 1 << 20 : This max value should limit risks of breaking user setups while fixing this bug. Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler") Signed-off-by: Eric Dumazet Diagnosed-by: Florian Westphal Reported-by: syzbot+dc9071cc5a85950bdfce@syzkaller.appspotmail.com Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_fq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/sched/sch_fq.c +++ b/net/sched/sch_fq.c @@ -736,7 +736,7 @@ static int fq_change(struct Qdisc *sch, if (tb[TCA_FQ_QUANTUM]) { u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); - if (quantum > 0) + if (quantum > 0 && quantum <= (1 << 20)) q->quantum = quantum; else err = -EINVAL;