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 9845FCD37A9 for ; Fri, 15 Sep 2023 20:38:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237368AbjIOUiJ (ORCPT ); Fri, 15 Sep 2023 16:38:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236626AbjIOUhg (ORCPT ); Fri, 15 Sep 2023 16:37:36 -0400 Received: from out-221.mta0.migadu.com (out-221.mta0.migadu.com [IPv6:2001:41d0:1004:224b::dd]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2655F106 for ; Fri, 15 Sep 2023 13:37:30 -0700 (PDT) Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1694810246; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=N9jUf0AezV9CUepWS4dSseHstKPiBlVXkzsuiSmuKZs=; b=cWsad2eNPDi2UIKGOD+rK2TaN1QvhdjuQcX8rGNgy8SnfvjEzileHeOHufHGj3aDmLH3MZ HTlyOocTWSj8YttEdbm9iyjRYNjHDlkY6KIxhOP3SPGMhhVN4H2QJ2jI4BBIXQ4my0x2I+ l/4eRZcSrWx2fUkUpdRgaB8UEBOexiQ= Date: Fri, 15 Sep 2023 21:37:22 +0100 MIME-Version: 1.0 Subject: Re: [PATCH] net: sched: drr: dont intepret cls results when asked to drop To: Ma Ke , jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230915142056.3411330-1-make_ruc2021@163.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Vadim Fedorenko In-Reply-To: <20230915142056.3411330-1-make_ruc2021@163.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15/09/2023 15:20, Ma Ke wrote: > If asked to drop a packet via TC_ACT_SHOT it is unsafe to > assume that res.class contains a valid pointer. > > Signed-off-by: Ma Ke > --- > net/sched/sch_drr.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c > index 19901e77cd3b..a535dc3b0e05 100644 > --- a/net/sched/sch_drr.c > +++ b/net/sched/sch_drr.c > @@ -310,6 +310,8 @@ static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch, > fl = rcu_dereference_bh(q->filter_list); > result = tcf_classify(skb, NULL, fl, &res, false); > if (result >= 0) { > + if (result == TC_ACT_SHOT) > + return NULL; With CONFIG_NET_CLS_ACT undefined tcf_classify can only return TC_ACT_UNSPEC and the if statement above is always false. Do you have any real issue you are trying to fix? > #ifdef CONFIG_NET_CLS_ACT > switch (result) { > case TC_ACT_QUEUED: > @@ -317,8 +319,6 @@ static struct drr_class *drr_classify(struct sk_buff *skb, struct Qdisc *sch, > case TC_ACT_TRAP: > *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; > fallthrough; > - case TC_ACT_SHOT: > - return NULL; > } > #endif > cl = (struct drr_class *)res.class;