From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934856Ab1KCBm5 (ORCPT ); Wed, 2 Nov 2011 21:42:57 -0400 Received: from cantor2.suse.de ([195.135.220.15]:51484 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934782Ab1KCBmu (ORCPT ); Wed, 2 Nov 2011 21:42:50 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Nov 2 15:27:47 2011 Message-Id: <20111102222747.843606094@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 02 Nov 2011 15:27:12 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jarek Poplawski , Eric Dumazet , "David S. Miller" , Ben Hutchings Subject: [088/101] gro: Re-fix different skb headrooms In-Reply-To: <20111102222755.GA10893@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.33-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Jarek Poplawski commit 64289c8e6851bca0e589e064c9a5c9fbd6ae5dd4 upstream. The patch: "gro: fix different skb headrooms" in its part: "2) allocate a minimal skb for head of frag_list" is buggy. The copied skb has p->data set at the ip header at the moment, and skb_gro_offset is the length of ip + tcp headers. So, after the change the length of mac header is skipped. Later skb_set_mac_header() sets it into the NET_SKB_PAD area (if it's long enough) and ip header is misaligned at NET_SKB_PAD + NET_IP_ALIGN offset. There is no reason to assume the original skb was wrongly allocated, so let's copy it as it was. bugzilla : https://bugzilla.kernel.org/show_bug.cgi?id=16626 fixes commit: 3d3be4333fdf6faa080947b331a6a19bce1a4f57 Reported-by: Plamen Petrov Signed-off-by: Jarek Poplawski CC: Eric Dumazet Acked-by: Eric Dumazet Tested-by: Plamen Petrov Signed-off-by: David S. Miller Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- net/core/skbuff.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2711,7 +2711,7 @@ int skb_gro_receive(struct sk_buff **hea } else if (skb_gro_len(p) != pinfo->gso_size) return -E2BIG; - headroom = NET_SKB_PAD + NET_IP_ALIGN; + headroom = skb_headroom(p); nskb = alloc_skb(headroom + skb_gro_offset(p), GFP_ATOMIC); if (unlikely(!nskb)) return -ENOMEM;