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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 ECC11C65BAF for ; Sun, 9 Dec 2018 22:17:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BBD542081F for ; Sun, 9 Dec 2018 22:17:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BBD542081F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727854AbeLIWHJ (ORCPT ); Sun, 9 Dec 2018 17:07:09 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:37164 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727274AbeLIWHB (ORCPT ); Sun, 9 Dec 2018 17:07:01 -0500 Received: from pub.yeoldevic.com ([81.174.156.145] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gW73I-0002if-Jh; Sun, 09 Dec 2018 21:55:52 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gW72c-0003LS-1O; Sun, 09 Dec 2018 21:55:10 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Alexander Aring" , "Rabi Narayan Sahoo" , "Stefan Schmidt" , "David Palma" Date: Sun, 09 Dec 2018 21:50:33 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 103/328] net: 6lowpan: fix reserved space for single frames In-Reply-To: X-SA-Exim-Connect-IP: 81.174.156.145 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.62-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Aring commit ac74f87c789af40936a80131c4759f3e72579c3a upstream. This patch fixes patch add handling to take care tail and headroom for single 6lowpan frames. We need to be sure we have a skb with the right head and tailroom for single frames. This patch do it by using skb_copy_expand() if head and tailroom is not enough allocated by upper layer. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=195059 Reported-by: David Palma Reported-by: Rabi Narayan Sahoo Signed-off-by: Alexander Aring Signed-off-by: Stefan Schmidt [bwh: Backported to 3.16: - s/ldev/dev/ - Adjust filename] Signed-off-by: Ben Hutchings --- net/ieee802154/6lowpan_rtnl.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) --- a/net/ieee802154/6lowpan_rtnl.c +++ b/net/ieee802154/6lowpan_rtnl.c @@ -388,9 +388,24 @@ static netdev_tx_t lowpan_xmit(struct sk /* We must take a copy of the skb before we modify/replace the ipv6 * header as the header could be used elsewhere */ - skb = skb_unshare(skb, GFP_ATOMIC); - if (!skb) - return NET_XMIT_DROP; + if (unlikely(skb_headroom(skb) < dev->needed_headroom || + skb_tailroom(skb) < dev->needed_tailroom)) { + struct sk_buff *nskb; + + nskb = skb_copy_expand(skb, dev->needed_headroom, + dev->needed_tailroom, GFP_ATOMIC); + if (likely(nskb)) { + consume_skb(skb); + skb = nskb; + } else { + kfree_skb(skb); + return NET_XMIT_DROP; + } + } else { + skb = skb_unshare(skb, GFP_ATOMIC); + if (!skb) + return NET_XMIT_DROP; + } ret = lowpan_header(skb, dev); if (ret < 0) {