From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net 2/6] cx82310_eth: use skb_cow_head() to deal with cloned skbs Date: Wed, 19 Apr 2017 09:59:22 -0700 Message-ID: <20170419165926.30631-3-edumazet@google.com> References: <20170419165926.30631-1-edumazet@google.com> Cc: netdev , James Hughes , Eric Dumazet , Eric Dumazet To: "David S . Miller" Return-path: Received: from mail-yb0-f180.google.com ([209.85.213.180]:32799 "EHLO mail-yb0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752788AbdDSQ7w (ORCPT ); Wed, 19 Apr 2017 12:59:52 -0400 Received: by mail-yb0-f180.google.com with SMTP id 81so8846520ybp.0 for ; Wed, 19 Apr 2017 09:59:46 -0700 (PDT) In-Reply-To: <20170419165926.30631-1-edumazet@google.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 --- drivers/net/usb/cx82310_eth.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/net/usb/cx82310_eth.c b/drivers/net/usb/cx82310_eth.c index e221bfcee76b40a3ad7ba60ec4d348f4b8f4cc73..947bea81d924124c3827e87f75e732e35adb2acd 100644 --- 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(struct usbnet *dev, struct sk_buff *skb, { 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); -- 2.12.2.816.g2cccc81164-goog