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=-3.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 7356CC352A4 for ; Wed, 12 Feb 2020 20:23:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3EC4121734 for ; Wed, 12 Feb 2020 20:23:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="a1guI9N1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728962AbgBLUXh (ORCPT ); Wed, 12 Feb 2020 15:23:37 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:43302 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727439AbgBLUXh (ORCPT ); Wed, 12 Feb 2020 15:23:37 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Transfer-Encoding:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=2Pf0jSF3zi7Uk2v8Judqp6wA4yzjcu8TqGWMZr8zWMU=; b=a1guI9N1hKkahCYzyQPOvSJcJZ Mrv+fB+gU4tju0reQiS9eQ3biRqjFCb4yBnem15YB2ICJND6Hw7mvZf9Av6Tiw5BkdxrDh8jBz4N4 1Lhgh1TtZWM7Ck/uCr8fWTGe/kZNf+GgsGOxgecNJU/0tlWjwLfTTCG9BHKophTsytDY=; Received: from andrew by vps0.lunn.ch with local (Exim 4.93) (envelope-from ) id 1j1yXk-0007YK-Vi; Wed, 12 Feb 2020 21:23:32 +0100 Date: Wed, 12 Feb 2020 21:23:32 +0100 From: Andrew Lunn To: Per =?iso-8859-1?Q?F=F6rlin?= Cc: "netdev@vger.kernel.org" , "john@phrozen.org" , "f.fainelli@gmail.com" Subject: Re: [Question] net: dsa: tag_qca: QCA tag and headroom size? Message-ID: <20200212202332.GV19213@lunn.ch> References: <1581501418212.84729@axis.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1581501418212.84729@axis.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Feb 12, 2020 at 09:57:00AM +0000, Per Förlin wrote: > Hi, > > --- > net/dsa/tag_qca.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/dsa/tag_qca.c b/net/dsa/tag_qca.c > index c8a128c9e5e0..70db7c909f74 100644 > --- a/net/dsa/tag_qca.c > +++ b/net/dsa/tag_qca.c > @@ -33,7 +33,7 @@ static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev) > struct dsa_port *dp = dsa_slave_to_port(dev); > u16 *phdr, hdr; > > - if (skb_cow_head(skb, 0) < 0) > > Is it really safe to assume there is enough headroom for the QCA tag? > > + if (skb_cow_head(skb, QCA_HDR_LEN) < 0) > > My proposal. Specify QCA tag size to make sure there is headroom. > > return NULL; > > skb_push(skb, QCA_HDR_LEN); Hi Per Yes, your change looks correct. ar9331_tag_xmit() also seems to have the same problem. Do you want to submit a patch? Thanks Andrew