From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net v2] net: test tailroom before appending to linear skb Date: Thu, 17 May 2018 10:18:15 -0700 Message-ID: <55d350d7-5450-b0ab-37e2-77bbb346d8a1@gmail.com> References: <20180517171329.201710-1-willemdebruijn.kernel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, Willem de Bruijn To: Willem de Bruijn , netdev@vger.kernel.org Return-path: Received: from mail-pl0-f67.google.com ([209.85.160.67]:37860 "EHLO mail-pl0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751494AbeEQRSW (ORCPT ); Thu, 17 May 2018 13:18:22 -0400 Received: by mail-pl0-f67.google.com with SMTP id w19-v6so2926412plq.4 for ; Thu, 17 May 2018 10:18:22 -0700 (PDT) In-Reply-To: <20180517171329.201710-1-willemdebruijn.kernel@gmail.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 05/17/2018 10:13 AM, Willem de Bruijn wrote: > From: Willem de Bruijn > > Device features may change during transmission. In particular with > corking, a device may toggle scatter-gather in between allocating > and writing to an skb. > > Do not unconditionally assume that !NETIF_F_SG at write time implies > that the same held at alloc time and thus the skb has sufficient > tailroom. > > This issue predates git history. > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Reported-by: Eric Dumazet > Signed-off-by: Willem de Bruijn > Reviewed-by: Eric Dumazet