Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968167AbeAOOQS (ORCPT + 1 other); Mon, 15 Jan 2018 09:16:18 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:46504 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965673AbeAOMjz (ORCPT ); Mon, 15 Jan 2018 07:39:55 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , James Hughes , "David S. Miller" , Oliver Neukum Subject: [PATCH 4.4 41/87] cx82310_eth: use skb_cow_head() to deal with cloned skbs Date: Mon, 15 Jan 2018 13:34:40 +0100 Message-Id: <20180115123353.516702889@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180115123349.252309699@linuxfoundation.org> References: <20180115123349.252309699@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit a9e840a2081ed28c2b7caa6a9a0041c950b3c37d upstream. We need to ensure there is enough headroom to push extra header, but we also need to check if we are allowed to change headers. skb_cow_head() is the proper helper to deal with this. Fixes: cc28a20e77b2 ("introduce cx82310_eth: Conexant CX82310-based ADSL router USB ethernet driver") Signed-off-by: Eric Dumazet Cc: James Hughes Signed-off-by: David S. Miller Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/cx82310_eth.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) --- a/drivers/net/usb/cx82310_eth.c +++ b/drivers/net/usb/cx82310_eth.c @@ -293,12 +293,9 @@ static struct sk_buff *cx82310_tx_fixup( { int len = skb->len; - if (skb_headroom(skb) < 2) { - struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags); + if (skb_cow_head(skb, 2)) { dev_kfree_skb_any(skb); - skb = skb2; - if (!skb) - return NULL; + return NULL; } skb_push(skb, 2);