From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH net] net: test tailroom before appending to linear skb Date: Thu, 17 May 2018 09:05:29 -0700 Message-ID: References: <20180517155437.120414-1-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-f65.google.com ([209.85.160.65]:37464 "EHLO mail-pl0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751047AbeEQQFb (ORCPT ); Thu, 17 May 2018 12:05:31 -0400 Received: by mail-pl0-f65.google.com with SMTP id w19-v6so2812788plq.4 for ; Thu, 17 May 2018 09:05:31 -0700 (PDT) In-Reply-To: <20180517155437.120414-1-willemdebruijn.kernel@gmail.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: On 05/17/2018 08:54 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 Excellent, thanks Willem. Reviewed-by: Eric Dumazet