From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754030Ab2DQFdd (ORCPT ); Tue, 17 Apr 2012 01:33:33 -0400 Received: from mail-wg0-f42.google.com ([74.125.82.42]:64059 "EHLO mail-wg0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752064Ab2DQFdc (ORCPT ); Tue, 17 Apr 2012 01:33:32 -0400 Subject: Re: [PATCH 3/6] macvtap: zerocopy: validate vector length before pinning user pages From: Eric Dumazet To: Jason Wang Cc: netdev@vger.kernel.org, xma@us.ibm.com, davem@davemloft.net, linux-kernel@vger.kernel.org, mst@redhat.com, ebiederm@xmission.com In-Reply-To: <4F8BD68F.7070708@redhat.com> References: <20120416060749.14140.19433.stgit@intel-e5620-16-2.englab.nay.redhat.com> <20120416060807.14140.96229.stgit@intel-e5620-16-2.englab.nay.redhat.com> <1334559183.28012.45.camel@edumazet-glaptop> <4F8BD68F.7070708@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 17 Apr 2012 07:33:28 +0200 Message-ID: <1334640808.2472.6.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2012-04-16 at 16:21 +0800, Jason Wang wrote: > Hi: > On 04/16/2012 02:53 PM, Eric Dumazet wrote: > if ((num_pages != size) || > >> (num_pages> MAX_SKB_FRAGS - skb_shinfo(skb)->nr_frags)) > >> > > Hi Jason > > > > Why is -EFAULT the right error code ? > > E2BIG or is there any error code you prefer? Might be good yes. However it sounds strange user cant write any size he wants (and kernel needs to build several skbs to fulfill user request)